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  • 1
    Publikationsdatum: 1998-12-18
    Beschreibung: CTLA-4, a negative regulator of T cell function, was found to associate with the T cell receptor (TCR) complex zeta chain in primary T cells. The association of TCRzeta with CTLA-4, reconstituted in 293 transfectants, was enhanced by p56(lck)-induced tyrosine phosphorylation. Coexpression of the CTLA-4-associated tyrosine phosphatase, SHP-2, resulted in dephosphorylation of TCRzeta bound to CTLA-4 and abolished the p56(lck)-inducible TCRzeta-CTLA-4 interaction. Thus, CTLA-4 inhibits TCR signal transduction by binding to TCRzeta and inhibiting tyrosine phosphorylation after T cell activation. These findings have broad implications for the negative regulation of T cell function and T cell tolerance.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Lee, K M -- Chuang, E -- Griffin, M -- Khattri, R -- Hong, D K -- Zhang, W -- Straus, D -- Samelson, L E -- Thompson, C B -- Bluestone, J A -- P01 AI35294-6/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1998 Dec 18;282(5397):2263-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Ben May Institute for Cancer Research, and Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9856951" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Abatacept ; Animals ; Antigens, CD ; Antigens, Differentiation/*metabolism ; CTLA-4 Antigen ; Cell Line ; Cells, Cultured ; Humans ; *Immunoconjugates ; Intracellular Signaling Peptides and Proteins ; *Lymphocyte Activation ; Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/genetics/metabolism ; Membrane Proteins/*metabolism ; Mice ; Mice, Inbred BALB C ; Models, Immunological ; Phosphorylation ; Phosphotyrosine/metabolism ; Protein Tyrosine Phosphatase, Non-Receptor Type 11 ; Protein Tyrosine Phosphatase, Non-Receptor Type 6 ; Protein Tyrosine Phosphatases/genetics/metabolism ; Receptors, Antigen, T-Cell/*metabolism ; Recombinant Fusion Proteins/metabolism ; SH2 Domain-Containing Protein Tyrosine Phosphatases ; *Signal Transduction ; T-Lymphocytes/*immunology ; Transfection ; src Homology Domains
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Publikationsdatum: 1998-02-21
    Beschreibung: Protein kinase B (PKB) is activated in response to phosphoinositide 3-kinases and their lipid products phosphatidylinositol 3,4, 5-trisphosphate [PtdIns(3,4,5)P3] and PtdIns(3,4)P2 in the signaling pathways used by a wide variety of growth factors, antigens, and inflammatory stimuli. PKB is a direct target of these lipids, but this regulation is complex. The lipids can bind to the pleckstrin homologous domain of PKB, causing its translocation to the membrane, and also enable upstream, Thr308-directed kinases to phosphorylate and activate PKB. Four isoforms of these PKB kinases were purified from sheep brain. They bound PtdIns(3,4,5)P3 and associated with lipid vesicles containing it. These kinases contain an NH2-terminal catalytic domain and a COOH-terminal pleckstrin homologous domain, and their heterologous expression augments receptor activation of PKB, which suggests they are the primary signal transducers that enable PtdIns(3,4,5)P3 or PtdIns- (3,4)P2 to activate PKB and hence to control signaling pathways regulating cell survival, glucose uptake, and glycogen metabolism.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Stephens, L -- Anderson, K -- Stokoe, D -- Erdjument-Bromage, H -- Painter, G F -- Holmes, A B -- Gaffney, P R -- Reese, C B -- McCormick, F -- Tempst, P -- Coadwell, J -- Hawkins, P T -- Wellcome Trust/United Kingdom -- New York, N.Y. -- Science. 1998 Jan 30;279(5351):710-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Inositide Laboratory, The Babraham Institute, Babraham, Cambridge CB2 4AT, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9445477" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3-Phosphoinositide-Dependent Protein Kinases ; Alternative Splicing ; Amino Acid Sequence ; Animals ; Cell Line ; Cell Membrane/enzymology ; Cloning, Molecular ; DNA, Complementary ; Drosophila ; Drosophila Proteins ; Enzyme Activation ; Humans ; Liposomes/metabolism ; Molecular Sequence Data ; Open Reading Frames ; Phosphatidylinositol Phosphates/*metabolism ; Phosphorylation ; Platelet-Derived Growth Factor/pharmacology ; Protein-Serine-Threonine Kinases/chemistry/genetics/isolation & ; purification/*metabolism ; Proto-Oncogene Proteins/*metabolism ; Proto-Oncogene Proteins c-akt ; Rats ; Recombinant Proteins/metabolism ; Sheep ; *Signal Transduction
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Publikationsdatum: 1998-08-28
    Beschreibung: A large protein complex mediates the phosphorylation of the inhibitor of kappaB (IkappaB), which results in the activation of nuclear factor kappaB (NF-kappaB). Two subunits of this complex, IkappaB kinase alpha (IKKalpha) and IkappaB kinase beta (IKKbeta), are required for NF-kappaB activation. Purified recombinant IKKalpha and IKKbeta expressed in insect cells were used to demonstrate that each protein can directly phosphorylate IkappaB proteins. IKKalpha and IKKbeta were found to form both homodimers and heterodimers. Both IKKalpha and IKKbeta phosphorylated IkappaB bound to NF-kappaB more efficiently than they phosphorylated free IkappaB. This result explains how free IkappaB can accumulate in cells in which IKK is still active and thus can contribute to the termination of NF-kappaB activation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zandi, E -- Chen, Y -- Karin, M -- AI 43477/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1998 Aug 28;281(5381):1360-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Gene Regulation and Signal Transduction, Department of Pharmacology, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9721103" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Cell Line ; Dimerization ; Enzyme Activation ; HeLa Cells ; Helix-Loop-Helix Motifs ; Humans ; I-kappa B Kinase ; Leucine Zippers ; Mutation ; NF-kappa B/antagonists & inhibitors/*metabolism ; Phosphorylation ; Protein-Serine-Threonine Kinases/chemistry/genetics/*metabolism ; Proto-Oncogene Proteins/*metabolism ; Recombinant Fusion Proteins/metabolism ; Recombinant Proteins/metabolism ; Spodoptera ; Transcription Factor RelB ; *Transcription Factors
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    Publikationsdatum: 1998-11-30
    Beschreibung: The NPH1 gene of Arabidopsis thaliana encodes a 120-kilodalton serine-threonine protein kinase hypothesized to function as a photoreceptor for phototropism. When expressed in insect cells, the NPH1 protein is phosphorylated in response to blue light irradiation. The biochemical and photochemical properties of the photosensitive protein reflect those of the native protein in microsomal membranes. Recombinant NPH1 noncovalently binds flavin mononucleotide, a likely chromophore for light-dependent autophosphorylation. The fluorescence excitation spectrum of the recombinant protein is similar to the action spectrum for phototropism, consistent with the conclusion that NPH1 is an autophosphorylating flavoprotein photoreceptor mediating phototropic responses in higher plants.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Christie, J M -- Reymond, P -- Powell, G K -- Bernasconi, P -- Raibekas, A A -- Liscum, E -- Briggs, W R -- New York, N.Y. -- Science. 1998 Nov 27;282(5394):1698-701.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Plant Biology, Carnegie Institution of Washington, 260 Panama Street, Stanford, CA 94305, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9831559" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Arabidopsis/genetics/*physiology ; *Arabidopsis Proteins ; Cell Line ; Cryptochromes ; *Drosophila Proteins ; *Eye Proteins ; Flavin Mononucleotide/metabolism ; Flavoproteins/physiology ; Genes, Plant ; Light ; Mutation ; Phosphoproteins/genetics/*metabolism ; Phosphorylation ; *Photoreceptor Cells, Invertebrate ; *Phototropism ; Protein-Serine-Threonine Kinases/genetics/*metabolism ; Receptors, G-Protein-Coupled ; Recombinant Proteins/metabolism ; Spectrometry, Fluorescence ; Spodoptera ; Transfection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-06-20
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hafen, E -- New York, N.Y. -- Science. 1998 May 22;280(5367):1212-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Zoologisches Institut der Universitat Zurich, Zurich, Switzerland. hafen@zool.unizh.ch〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9634402" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinase Type 4 ; Calcium-Calmodulin-Dependent Protein Kinases/metabolism ; Cyclic AMP Response Element-Binding Protein/metabolism ; Down-Regulation ; Dual Specificity Phosphatase 6 ; Enzyme Activation ; Mitogen-Activated Protein Kinase 1 ; Phosphoprotein Phosphatases/*metabolism ; Phosphorylation ; Protein Kinases/*metabolism ; Protein Tyrosine Phosphatases/metabolism ; *Signal Transduction
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Publikationsdatum: 1998-09-11
    Beschreibung: Leptin is a hormone that regulates food intake, and its receptor (OB-Rb) is expressed primarily in the hypothalamus. Here, it is shown that OB-Rb is also expressed in human vasculature and in primary cultures of human endothelial cells. In vitro and in vivo assays revealed that leptin has angiogenic activity. In vivo, leptin induced neovascularization in corneas from normal rats but not in corneas from fa/fa Zucker rats, which lack functional leptin receptors. These observations indicate that the vascular endothelium is a target for leptin and suggest a physiological mechanism whereby leptin-induced angiogenesis may facilitate increased energy expenditure.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sierra-Honigmann, M R -- Nath, A K -- Murakami, C -- Garcia-Cardena, G -- Papapetropoulos, A -- Sessa, W C -- Madge, L A -- Schechner, J S -- Schwabb, M B -- Polverini, P J -- Flores-Riveros, J R -- New York, N.Y. -- Science. 1998 Sep 11;281(5383):1683-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, CT 06536, USA. rocio_sierra-honigmann@qm.yale.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9733517" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adipocytes/metabolism ; Amino Acid Sequence ; Animals ; Carrier Proteins/analysis/*physiology ; Cells, Cultured ; Corneal Neovascularization ; DNA-Binding Proteins/metabolism ; Endothelial Growth Factors/pharmacology ; Endothelium, Vascular/chemistry/cytology/*physiology ; Energy Metabolism ; Humans ; Leptin ; Lipid Metabolism ; Lymphokines/pharmacology ; Molecular Sequence Data ; *Neovascularization, Physiologic ; Phosphorylation ; Proteins/pharmacology/*physiology ; Rats ; Rats, Zucker ; *Receptors, Cell Surface ; Receptors, Leptin ; STAT3 Transcription Factor ; Trans-Activators/metabolism ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Publikationsdatum: 1998-09-11
    Beschreibung: The p53 tumor suppressor protein is activated and phosphorylated on serine-15 in response to various DNA damaging agents. The gene product mutated in ataxia telangiectasia, ATM, acts upstream of p53 in a signal transduction pathway initiated by ionizing radiation. Immunoprecipitated ATM had intrinsic protein kinase activity and phosphorylated p53 on serine-15 in a manganese-dependent manner. Ionizing radiation, but not ultraviolet radiation, rapidly enhanced this p53-directed kinase activity of endogenous ATM. These observations, along with the fact that phosphorylation of p53 on serine-15 in response to ionizing radiation is reduced in ataxia telangiectasia cells, suggest that ATM is a protein kinase that phosphorylates p53 in vivo.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Canman, C E -- Lim, D S -- Cimprich, K A -- Taya, Y -- Tamai, K -- Sakaguchi, K -- Appella, E -- Kastan, M B -- Siliciano, J D -- CA71387/CA/NCI NIH HHS/ -- ES05777/ES/NIEHS NIH HHS/ -- New York, N.Y. -- Science. 1998 Sep 11;281(5383):1677-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉The Johns Hopkins School of Medicine, Oncology Center, Baltimore, MD 21205, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9733515" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Ataxia Telangiectasia Mutated Proteins ; Cell Cycle Proteins ; Cell Line ; DNA Damage ; DNA-Activated Protein Kinase ; *DNA-Binding Proteins ; Enzyme Activation ; Humans ; Lymphocytes/metabolism/radiation effects ; Mutation ; Nuclear Proteins ; Phosphatidylinositol 3-Kinases/metabolism ; Phosphorylation ; Phosphoserine/metabolism ; Protein Kinases/*metabolism ; Protein-Serine-Threonine Kinases/metabolism ; Proteins/genetics/*metabolism ; *Radiation, Ionizing ; Recombinant Fusion Proteins/metabolism ; Recombinant Proteins/metabolism ; Signal Transduction ; Transfection ; Tumor Suppressor Protein p53/*metabolism ; Tumor Suppressor Proteins ; Ultraviolet Rays
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-07-17
    Beschreibung: Activation of nonreceptor protein tyrosine kinases (PTKs) is essential for T cell receptor (TCR) responsiveness; however, the function of individual PTK substrates is often uncertain. A mutant T cell line was isolated that lacked expression of SLP-76 (SH2 domain-containing leukocyte protein of 76 kilodaltons), a hematopoietically expressed adaptor protein and PTK substrate. SLP-76 was not required for TCR-induced tyrosine phosphorylation of most proteins, but was required for optimal tyrosine phosphorylation and activation of phospholipase C-gamma1 (PLC-gamma1), as well as Ras pathway activation. TCR-inducible gene expression was dependent on SLP-76. Thus, coupling of TCR-regulated PTKs to downstream signaling pathways requires SLP-76.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yablonski, D -- Kuhne, M R -- Kadlecek, T -- Weiss, A -- CA72531/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1998 Jul 17;281(5375):413-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine, Howard Hughes Medical Institute, Box 0795, University of California, San Francisco, San Francisco, CA 94143-0795, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9665884" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Adaptor Proteins, Signal Transducing ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinases/metabolism ; Carrier Proteins/metabolism ; Cell Line ; DNA-Binding Proteins/metabolism ; Enzyme Activation ; Gene Expression Regulation ; Humans ; Inositol Phosphates/metabolism ; Interleukin-2/genetics ; Isoenzymes/*metabolism ; Jurkat Cells ; *Membrane Proteins ; Mitogen-Activated Protein Kinase 1 ; NFATC Transcription Factors ; *Nuclear Proteins ; Phospholipase C gamma ; Phosphoproteins/metabolism/*physiology ; Phosphorylation ; Phosphotyrosine/metabolism ; Protein-Tyrosine Kinases/*metabolism ; Receptors, Antigen, T-Cell/*metabolism ; Signal Transduction ; T-Lymphocytes/enzymology/*metabolism ; Transcription Factors/metabolism ; Transcriptional Activation ; Transfection ; Type C Phospholipases/*metabolism ; ras Proteins/metabolism
    Print ISSN: 0036-8075
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-11-13
    Beschreibung: Many cell surface proteins are marked for endocytosis by a cytoplasmic sequence motif, tyrosine-X-X-(hydrophobic residue), that is recognized by the mu2 subunit of AP2 adaptors. Crystal structures of the internalization signal binding domain of mu2 complexed with the internalization signal peptides of epidermal growth factor receptor and the trans-Golgi network protein TGN38 have been determined at 2.7 angstrom resolution. The signal peptides adopted an extended conformation rather than the expected tight turn. Specificity was conferred by hydrophobic pockets that bind the tyrosine and leucine in the peptide. In the crystal, the protein forms dimers that could increase the strength and specificity of binding to dimeric receptors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Owen, D J -- Evans, P R -- New York, N.Y. -- Science. 1998 Nov 13;282(5392):1327-32.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9812899" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Adaptor Protein Complex 1 ; Adaptor Protein Complex 2 ; *Adaptor Protein Complex 3 ; Adaptor Protein Complex alpha Subunits ; *Adaptor Protein Complex mu Subunits ; Adaptor Proteins, Vesicular Transport ; Amino Acid Sequence ; Animals ; Binding Sites ; Crystallography, X-Ray ; Dimerization ; *Endocytosis ; *Glycoproteins ; Humans ; Hydrogen Bonding ; Membrane Glycoproteins/*chemistry/metabolism ; Membrane Proteins/*chemistry/metabolism ; Models, Molecular ; Molecular Sequence Data ; Phosphorylation ; Protein Conformation ; Protein Sorting Signals/*chemistry/metabolism ; Protein Structure, Secondary ; Receptor, Epidermal Growth Factor/*chemistry/metabolism ; Tyrosine/chemistry/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 10
    Publikationsdatum: 1998-12-04
    Beschreibung: Targeted disruption of the gene encoding MEK kinase 1 (MEKK1), a mitogen-activated protein kinase (MAPK) kinase kinase, defined its function in the regulation of MAPK pathways and cell survival. MEKK1(-/-) embryonic stem cells from mice had lost or altered responses of the c-Jun amino-terminal kinase (JNK) to microtubule disruption and cold stress but activated JNK normally in response to heat shock, anisomycin, and ultraviolet irradiation. Activation of JNK was lost and that of extracellular signal-regulated protein kinase (ERK) was diminished in response to hyperosmolarity and serum factors in MEKK1(-/-) cells. Loss of MEKK1 expression resulted in a greater apoptotic response of cells to hyperosmolarity and microtubule disruption. When activated by specific stresses that alter cell shape and the cytoskeleton, MEKK1 signals to protect cells from apoptosis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yujiri, T -- Sather, S -- Fanger, G R -- Johnson, G L -- DK37871/DK/NIDDK NIH HHS/ -- GM30324/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Dec 4;282(5395):1911-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Program in Molecular Signal Transduction, Division of Basic Sciences, National Jewish Medical and Research Center, Denver, CO 80206, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9836645" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Anisomycin/pharmacology ; Apoptosis ; Calcium-Calmodulin-Dependent Protein Kinases/*metabolism ; Cell Line ; Cell Size ; *Cell Survival ; Enzyme Activation ; Gene Targeting ; JNK Mitogen-Activated Protein Kinases ; Lysophospholipids/pharmacology ; *MAP Kinase Kinase 4 ; *MAP Kinase Kinase Kinase 1 ; Mice ; *Mitogen-Activated Protein Kinase Kinases ; *Mitogen-Activated Protein Kinases ; Nocodazole/pharmacology ; Osmolar Concentration ; Phosphorylation ; Protein-Serine-Threonine Kinases/genetics/*metabolism ; Protein-Tyrosine Kinases/metabolism ; Recombinant Proteins/metabolism ; Stem Cells ; Temperature ; Transfection ; Ultraviolet Rays
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 11
    Publikationsdatum: 1998-09-04
    Beschreibung: Recruitment of the coactivator, CREB binding protein (CBP), by signal-regulated transcription factors, such as CREB [adenosine 3', 5'-monophosphate (cAMP) response element binding protein], is critical for stimulation of gene expression. The mouse pituitary cell line AtT20 was used to show that the CBP recruitment step (CREB phosphorylation on serine-133) can be uncoupled from CREB/CBP-activated transcription. CBP was found to contain a signal-regulated transcriptional activation domain that is controlled by nuclear calcium and calcium/calmodulin-dependent (CaM) protein kinase IV and by cAMP. Cytoplasmic calcium signals that stimulate the Ras mitogen-activated protein kinase signaling cascade or expression of the activated form of Ras provided the CBP recruitment signal but did not increase CBP activity and failed to activate CREB- and CBP-mediated transcription. These results identify CBP as a signal-regulated transcriptional coactivator and define a regulatory role for nuclear calcium and cAMP in CBP-dependent gene expression.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chawla, S -- Hardingham, G E -- Quinn, D R -- Bading, H -- New York, N.Y. -- Science. 1998 Sep 4;281(5382):1505-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Medical Research Council, Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9727976" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; CREB-Binding Protein ; Calcium/*metabolism ; Calcium Channels/metabolism ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinase Type 4 ; Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors/*metabolism ; Cell Line ; Cell Nucleus/*metabolism ; Cyclic AMP/metabolism ; Cyclic AMP Response Element-Binding Protein/metabolism ; Cytoplasm/metabolism ; Genes, Reporter ; Mice ; Models, Genetic ; Nuclear Proteins/*metabolism ; Phosphorylation ; Phosphoserine/metabolism ; Recombinant Fusion Proteins/metabolism ; Signal Transduction ; Trans-Activators/*metabolism ; Transcription, Genetic ; *Transcriptional Activation ; ras Proteins/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 12
    Publikationsdatum: 1998-02-28
    Beschreibung: The calcium-calmodulin-dependent kinase II (CaMKII) is required for hippocampal long-term potentiation (LTP) and spatial learning. In addition to its calcium-calmodulin (CaM)-dependent activity, CaMKII can undergo autophosphorylation, resulting in CaM-independent activity. A point mutation was introduced into the alphaCaMKII gene that blocked the autophosphorylation of threonine at position 286 (Thr286) of this kinase without affecting its CaM-dependent activity. The mutant mice had no N-methyl-D-aspartate receptor-dependent LTP in the hippocampal CA1 area and showed no spatial learning in the Morris water maze. Thus, the autophosphorylation of alphaCaMKII at Thr286 appears to be required for LTP and learning.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Giese, K P -- Fedorov, N B -- Filipkowski, R K -- Silva, A J -- AG13622/AG/NIA NIH HHS/ -- New York, N.Y. -- Science. 1998 Feb 6;279(5352):870-3.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9452388" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 2-Amino-5-phosphonovalerate/pharmacology ; 6-Cyano-7-nitroquinoxaline-2,3-dione/pharmacology ; Animals ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinases/genetics/*metabolism ; Calmodulin/metabolism ; Gene Targeting ; Hippocampus/metabolism/*physiology ; *Long-Term Potentiation/drug effects ; *Maze Learning ; Mice ; Mice, Inbred C57BL ; Mice, Mutant Strains ; Patch-Clamp Techniques ; Phosphorylation ; Phosphothreonine/metabolism ; Picrotoxin/pharmacology ; Point Mutation ; Pyramidal Cells/*physiology ; Receptors, N-Methyl-D-Aspartate/physiology ; Synaptic Transmission
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 13
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-12-18
    Beschreibung: Transforming growth factor-beta (TGF-beta) inhibits cell proliferation, and acquisition of TGF-beta resistance has been linked to tumorigenesis. A genetic screen was performed to identify complementary DNAs that abrogated TGF-beta sensitivity in mink lung epithelial cells. Ectopic expression of murine double minute 2 rescued TGF-beta-induced growth arrest in a p53-independent manner by interference with retinoblastoma susceptibility gene product (Rb)/E2F function. In human breast tumor cells, increased MDM2 expression levels correlated with TGF-beta resistance. Thus, MDM2 may confer TGF-beta resistance in a subset of tumors and may promote tumorigenesis by interference with two independent tumor suppressors, p53 and Rb.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, P -- Dong, P -- Dai, K -- Hannon, G J -- Beach, D -- New York, N.Y. -- Science. 1998 Dec 18;282(5397):2270-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9856953" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Breast Neoplasms/genetics/metabolism/pathology ; *Carrier Proteins ; *Cell Cycle Proteins ; *Cell Division ; Cell Line ; Cell Transformation, Neoplastic ; *DNA-Binding Proteins ; Drug Resistance, Neoplasm ; E2F Transcription Factors ; Gene Expression ; Genes, Retinoblastoma ; Genes, p53 ; Genetic Vectors ; Humans ; Mice ; Mink ; *Nuclear Proteins ; Phosphorylation ; Proto-Oncogene Proteins/genetics/*physiology ; Proto-Oncogene Proteins c-mdm2 ; Retinoblastoma Protein/metabolism ; Retinoblastoma-Binding Protein 1 ; Signal Transduction ; Transcription Factor DP1 ; Transcription Factors/genetics/metabolism ; Transcription, Genetic ; Transforming Growth Factor beta/*pharmacology/physiology ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53/*physiology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 14
    Publikationsdatum: 1998-06-11
    Beschreibung: The tumor suppressor PTEN is a phosphatase with sequence similarity to the cytoskeletal protein tensin. Here the cellular roles of PTEN were investigated. Overexpression of PTEN inhibited cell migration, whereas antisense PTEN enhanced migration. Integrin-mediated cell spreading and the formation of focal adhesions were down-regulated by wild-type PTEN but not by PTEN with an inactive phosphatase domain. PTEN interacted with the focal adhesion kinase FAK and reduced its tyrosine phosphorylation. Overexpression of FAK partially antagonized the effects of PTEN. Thus, PTEN phosphatase may function as a tumor suppressor by negatively regulating cell interactions with the extracellular matrix.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tamura, M -- Gu, J -- Matsumoto, K -- Aota, S -- Parsons, R -- Yamada, K M -- New York, N.Y. -- Science. 1998 Jun 5;280(5369):1614-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Craniofacial Developmental Biology and Regeneration Branch, National Institute of Dental Research, National Institutes of Health, Bethesda, MD 20892-4370, USA. mtamura@yoda.nidr.nih.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9616126" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3T3 Cells ; Animals ; *Cell Adhesion ; Cell Adhesion Molecules/metabolism ; Cell Line ; *Cell Movement ; Cell Size ; Concanavalin A ; Down-Regulation ; Ecdysone/pharmacology ; Fibronectins ; Focal Adhesion Kinase 1 ; Focal Adhesion Protein-Tyrosine Kinases ; Genes, Tumor Suppressor ; Humans ; Integrins/physiology ; Mice ; Mutation ; PTEN Phosphohydrolase ; *Phosphoric Monoester Hydrolases ; Phosphorylation ; Polylysine ; Protein Tyrosine Phosphatases/genetics/metabolism/pharmacology/*physiology ; Protein-Tyrosine Kinases/metabolism ; Recombinant Proteins/pharmacology ; Signal Transduction ; Transfection ; Tumor Cells, Cultured ; *Tumor Suppressor Proteins
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 15
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-07-10
    Beschreibung: The Rad53 protein kinase of Saccharomyces cerevisiae is required for checkpoints that prevent cell division in cells with damaged or incompletely replicated DNA. The Rad9 protein was phosphorylated in response to DNA damage, and phosphorylated Rad9 interacted with the COOH-terminal forkhead homology-associated (FHA) domain of Rad53. Inactivation of this domain abolished DNA damage-dependent Rad53 phosphorylation, G2/M cell cycle phase arrest, and increase of RNR3 transcription but did not affect replication inhibition-dependent Rad53 phosphorylation. Thus, Rad53 integrates DNA damage signals by coupling with phosphorylated Rad9. The hitherto uncharacterized FHA domain appears to be a modular protein-binding domain.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Sun, Z -- Hsiao, J -- Fay, D S -- Stern, D F -- New York, N.Y. -- Science. 1998 Jul 10;281(5374):272-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biology, Yale University, New Haven, CT 06511, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9657725" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; *Cell Cycle Proteins ; Checkpoint Kinase 2 ; *DNA Damage ; DNA Replication/drug effects ; Fungal Proteins/*metabolism ; G2 Phase ; Hydroxyurea/pharmacology ; Methyl Methanesulfonate/pharmacology ; Mitosis ; Mutation ; Oligopeptides ; Peptides ; Phosphorylation ; Protein Kinases/chemistry/genetics/*metabolism ; *Protein-Serine-Threonine Kinases ; Saccharomyces cerevisiae/cytology/*metabolism ; *Saccharomyces cerevisiae Proteins ; Transcription, Genetic
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 16
    Publikationsdatum: 1998-01-24
    Beschreibung: The function and regulation of the receptorlike transmembrane protein tyrosine phosphatases (RPTPs) are not well understood. Ligand-induced dimerization inhibited the function of the epidermal growth factor receptor (EGFR)-RPTP CD45 chimera (EGFR-CD45) in T cell signal transduction. Properties of mutated EGFR-CD45 chimeras supported a general model for the regulation of RPTPs, derived from the crystal structure of the RPTPalpha membrane-proximal phosphatase domain. The phosphatase domain apparently forms a symmetrical dimer in which the catalytic site of one molecule is blocked by specific contacts with a wedge from the other.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Majeti, R -- Bilwes, A M -- Noel, J P -- Hunter, T -- Weiss, A -- New York, N.Y. -- Science. 1998 Jan 2;279(5347):88-91.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology, University of California, San Francisco, CA 94143, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9417031" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Antigens, CD45/chemistry/*metabolism ; Binding Sites ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinases/metabolism ; Dimerization ; Epidermal Growth Factor/metabolism/pharmacology ; Humans ; Ligands ; Lymphocyte Activation ; Mutation ; Phosphorylation ; Protein Tyrosine Phosphatases/*antagonists & inhibitors/chemistry/metabolism ; Protein-Tyrosine Kinases/metabolism ; Receptor, Epidermal Growth Factor/chemistry/metabolism ; Receptors, Antigen, T-Cell/metabolism ; Recombinant Fusion Proteins/antagonists & inhibitors/chemistry/metabolism ; Signal Transduction ; T-Lymphocytes/immunology/*metabolism ; Tumor Cells, Cultured ; ZAP-70 Protein-Tyrosine Kinase
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 17
    Publikationsdatum: 1998-11-13
    Beschreibung: Caspases are intracellular proteases that function as initiators and effectors of apoptosis. The kinase Akt and p21-Ras, an Akt activator, induced phosphorylation of pro-caspase-9 (pro-Casp9) in cells. Cytochrome c-induced proteolytic processing of pro-Casp9 was defective in cytosolic extracts from cells expressing either active Ras or Akt. Akt phosphorylated recombinant Casp9 in vitro on serine-196 and inhibited its protease activity. Mutant pro-Casp9(Ser196Ala) was resistant to Akt-mediated phosphorylation and inhibition in vitro and in cells, resulting in Akt-resistant induction of apoptosis. Thus, caspases can be directly regulated by protein phosphorylation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Cardone, M H -- Roy, N -- Stennicke, H R -- Salvesen, G S -- Franke, T F -- Stanbridge, E -- Frisch, S -- Reed, J C -- CA-69381/CA/NCI NIH HHS/ -- CA-69515/CA/NCI NIH HHS/ -- New York, N.Y. -- Science. 1998 Nov 13;282(5392):1318-21.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Program on Apoptosis and Cell Death Research, The Burnham Institute, La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9812896" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Apoptosis ; Caspase 9 ; Caspase Inhibitors ; Caspases/*metabolism ; Cell Line ; Cytochrome c Group/pharmacology ; Enzyme Precursors/metabolism ; Humans ; Mass Spectrometry ; Mutation ; Peptide Fragments/metabolism ; Phosphorylation ; Phosphoserine/metabolism ; Protein-Serine-Threonine Kinases/metabolism ; Proto-Oncogene Proteins/metabolism ; Proto-Oncogene Proteins c-akt ; Proto-Oncogene Proteins p21(ras)/metabolism ; Recombinant Fusion Proteins/metabolism ; Transfection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 18
    Publikationsdatum: 1998-11-30
    Beschreibung: Proteolysis of mitotic cyclins depends on a multisubunit ubiquitin-protein ligase, the anaphase promoting complex (APC). Proteolysis commences during anaphase, persisting throughout G1 until it is terminated by cyclin-dependent kinases (CDKs) as cells enter S phase. Proteolysis of mitotic cyclins in yeast was shown to require association of the APC with the substrate-specific activator Hct1 (also called Cdh1). Phosphorylation of Hct1 by CDKs blocked the Hct1-APC interaction. The mutual inhibition between APC and CDKs explains how cells suppress mitotic CDK activity during G1 and then establish a period with elevated kinase activity from S phase until anaphase.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Zachariae, W -- Schwab, M -- Nasmyth, K -- Seufert, W -- New York, N.Y. -- Science. 1998 Nov 27;282(5394):1721-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Research Institute of Molecular Pathology, Dr. Bohr-Gasse 7, A-1030 Vienna, Austria.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9831566" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Anaphase ; Anaphase-Promoting Complex-Cyclosome ; CDC2 Protein Kinase/metabolism ; Cdh1 Proteins ; Cyclin-Dependent Kinases/*metabolism ; Cyclins/*metabolism ; Fungal Proteins/*metabolism ; G1 Phase ; Ligases/*metabolism ; Mitosis ; Phosphorylation ; Recombinant Fusion Proteins/metabolism ; S Phase ; Saccharomyces cerevisiae/cytology/*metabolism ; *Saccharomyces cerevisiae Proteins ; *Ubiquitin-Protein Ligase Complexes ; Ubiquitin-Protein Ligases ; Ubiquitins/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 19
    Publikationsdatum: 1998-09-25
    Beschreibung: Phosphorylation sites in members of the protein kinase A (PKA), PKG, and PKC kinase subfamily are conserved. Thus, the PKB kinase PDK1 may be responsible for the phosphorylation of PKC isotypes. PDK1 phosphorylated the activation loop sites of PKCzeta and PKCdelta in vitro and in a phosphoinositide 3-kinase (PI 3-kinase)-dependent manner in vivo in human embryonic kidney (293) cells. All members of the PKC family tested formed complexes with PDK1. PDK1-dependent phosphorylation of PKCdelta in vitro was stimulated by combined PKC and PDK1 activators. The activation loop phosphorylation of PKCdelta in response to serum stimulation of cells was PI 3-kinase-dependent and was enhanced by PDK1 coexpression.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Le Good, J A -- Ziegler, W H -- Parekh, D B -- Alessi, D R -- Cohen, P -- Parker, P J -- New York, N.Y. -- Science. 1998 Sep 25;281(5385):2042-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Protein Phosphorylation Laboratory, Imperial Cancer Research Fund, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9748166" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3-Phosphoinositide-Dependent Protein Kinases ; Binding Sites ; Cell Line ; Chromones/pharmacology ; Enzyme Activation ; Enzyme Inhibitors/pharmacology ; Humans ; Isoenzymes/*metabolism ; Morpholines/pharmacology ; Phosphatidylcholines/pharmacology ; Phosphatidylinositol 3-Kinases/*metabolism ; Phosphatidylinositol Phosphates ; Phosphatidylserines/pharmacology ; Phosphorylation ; Protein Kinase C/*metabolism ; Protein Kinase C beta ; Protein-Serine-Threonine Kinases/*metabolism ; Recombinant Proteins/metabolism ; Tetradecanoylphorbol Acetate/pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 20
    Publikationsdatum: 1998-02-07
    Beschreibung: Mitogen stimulation of cytoskeletal changes and c-jun amino-terminal kinases is mediated by Rac small guanine nucleotide-binding proteins. Vav, a guanosine diphosphate (GDP)-guanosine triphosphate (GTP) exchange factor for Rac that stimulates the exchange of bound GDP for GTP, bound to and was directly controlled by substrates and products of phosphoinositide (PI) 3-kinase. The PI 3-kinase substrate phosphatidylinositol-4,5-bisphosphate inhibited activation of Vav by the tyrosine kinase Lck, whereas the product phosphatidylinositol-3,4,5-trisphosphate enhanced phosphorylation and activation of Vav by Lck. Control of Vav in response to mitogens by the products of PI 3-kinase suggests a mechanism for Ras-dependent activation of Rac.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Han, J -- Luby-Phelps, K -- Das, B -- Shu, X -- Xia, Y -- Mosteller, R D -- Krishna, U M -- Falck, J R -- White, M A -- Broek, D -- CA50261/CA/NCI NIH HHS/ -- CA71443/CA/NCI NIH HHS/ -- GM31278/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Jan 23;279(5350):558-60.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biochemistry and Molecular Biology, Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90033-0800, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9438848" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Cell Line ; Enzyme Activation ; GTP Phosphohydrolases/*metabolism ; GTP-Binding Proteins/*metabolism ; Guanine Nucleotide Exchange Factors ; Guanosine Diphosphate/*metabolism ; Guanosine Triphosphate/metabolism ; Inositol 1,4,5-Trisphosphate/metabolism/pharmacology ; Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism ; Mutagenesis, Site-Directed ; Oncogene Proteins/chemistry/*metabolism ; Phosphatidylinositol 3-Kinases/*metabolism ; Phosphatidylinositol 4,5-Diphosphate/metabolism/pharmacology ; Phosphatidylinositol Phosphates/metabolism/pharmacology ; Phosphatidylinositols/*metabolism/pharmacology ; Phosphorylation ; Proteins/metabolism ; Proto-Oncogene Proteins c-vav ; Rats ; rac GTP-Binding Proteins ; ras Guanine Nucleotide Exchange Factors
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 21
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-01-07
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Vogel, G -- New York, N.Y. -- Science. 1997 Dec 12;278(5345):1883-4.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9417635" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Binding Sites ; *Cell Cycle Proteins ; *Cell Division ; Humans ; *Mitosis ; Models, Molecular ; Peptidylprolyl Isomerase/chemistry/*metabolism ; Phosphoproteins/*metabolism ; Phosphorylation ; Proline/metabolism ; Protein Conformation ; Protein-Serine-Threonine Kinases/metabolism ; Yeasts/cytology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 22
    Publikationsdatum: 1998-01-07
    Beschreibung: Pin1 is an essential and conserved mitotic peptidyl-prolyl isomerase (PPIase) that is distinct from members of two other families of conventional PPIases, cyclophilins and FKBPs (FK-506 binding proteins). In response to their phosphorylation during mitosis, Pin1 binds and regulates members of a highly conserved set of proteins that overlaps with antigens recognized by the mitosis-specific monoclonal antibody MPM-2. Pin1 is here shown to be a phosphorylation-dependent PPIase that specifically recognizes the phosphoserine-proline or phosphothreonine-proline bonds present in mitotic phosphoproteins. Both Pin1 and MPM-2 selected similar phosphorylated serine-proline-containing peptides, providing the basis for the specific interaction between Pin1 and MPM-2 antigens. Pin1 preferentially isomerized proline residues preceded by phosphorylated serine or threonine with up to 1300-fold selectivity compared with unphosphorylated peptides. Pin1 may thus regulate mitotic progression by catalyzing sequence-specific and phosphorylation-dependent proline isomerization.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Yaffe, M B -- Schutkowski, M -- Shen, M -- Zhou, X Z -- Stukenberg, P T -- Rahfeld, J U -- Xu, J -- Kuang, J -- Kirschner, M W -- Fischer, G -- Cantley, L C -- Lu, K P -- GM56203/GM/NIGMS NIH HHS/ -- GM56230/GM/NIGMS NIH HHS/ -- R01 GM056203/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1997 Dec 12;278(5345):1957-60.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Medicine Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9395400" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Isomerases/metabolism ; Antibodies, Monoclonal ; Binding Sites ; Carrier Proteins/metabolism ; Cell Cycle Proteins/chemistry/*metabolism ; DNA-Binding Proteins/metabolism ; Epitopes ; HeLa Cells ; Heat-Shock Proteins/metabolism ; Humans ; Isomerism ; *Mitosis ; Models, Molecular ; Oligopeptides/chemistry/*metabolism ; Peptide Library ; Peptidylprolyl Isomerase/chemistry/*metabolism ; Phosphoproteins/chemistry/immunology/*metabolism ; Phosphorylation ; Phosphoserine/metabolism ; Phosphothreonine/metabolism ; Proline/*metabolism ; Protein Conformation ; Recombinant Fusion Proteins/chemistry/metabolism ; Substrate Specificity ; Tacrolimus Binding Proteins
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 23
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-11-30
    Beschreibung: The Xenopus polo-like kinase 1 (Plx1) is essential during mitosis for the activation of Cdc25C, for spindle assembly, and for cyclin B degradation. Polo-like kinases from various organisms are activated by phosphorylation by an unidentified protein kinase. A protein kinase, polo-like kinase kinase 1 or xPlkk1, that phosphorylates and activates Plx1 in vitro was purified to near homogeneity and cloned. Phosphopeptide mapping of Plx1 phosphorylated in vitro by recombinant xPlkk1 or in progesterone-treated oocytes indicates that xPlkk1 may activate Plx1 in vivo. The xPlkk1 protein itself was also activated by phosphorylation on serine and threonine residues, and the kinetics of activation of xPlkk1 in vivo closely paralleled the activation of Plx1. Moreover, microinjection of xPlkk1 into Xenopus oocytes accelerated the timing of activation of Plx1 and the transition from G2 to M phase of the cell cycle. These results define a protein kinase cascade that regulates several events of mitosis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Qian, Y W -- Erikson, E -- Maller, J L -- CA46934/CA/NCI NIH HHS/ -- GM26743/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Nov 27;282(5394):1701-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Pharmacology, University of Colorado School of Medicine, Denver, Colorado 80262, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9831560" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/metabolism ; Amino Acid Sequence ; Animals ; Catalytic Domain ; Cell Cycle Proteins ; Cloning, Molecular ; Enzyme Activation ; Mitosis ; Molecular Sequence Data ; Okadaic Acid/pharmacology ; Oocytes/enzymology ; Peptide Mapping ; Phosphoprotein Phosphatases/metabolism ; Phosphorylation ; Progesterone/pharmacology ; Protein-Serine-Threonine Kinases/chemistry/genetics/*isolation & ; purification/*metabolism ; Recombinant Fusion Proteins/metabolism ; Xenopus ; *Xenopus Proteins
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 24
    Publikationsdatum: 1998-09-11
    Beschreibung: Signal transduction is controlled both by regulation of enzyme activation and by organization of enzymatic complexes with nonenzymatic adapters, scaffolds, and anchor proteins. The extracellular signal-regulated kinase (ERK) cascade is one of several evolutionarily conserved mitogen-activated protein (MAP) kinase cascades important in the regulation of growth, apoptosis, and differentiation. A two-hybrid screen was conducted to identify nonenzymatic components of this signaling cascade that might be important in regulating its activity. A protein called MP1 (MEK Partner 1) was identified that bound specifically to MEK1 and ERK1 and facilitated their activation. When overexpressed in cultured cells, MP1 enhanced activation of ERK1 and activation of a reporter driven by the transcription factor Elk-1. Expression of MP1 in cells increased binding of ERK1 to MEK1. MP1 apparently functions as an adapter to enhance the efficiency of the MAP kinase cascade.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Schaeffer, H J -- Catling, A D -- Eblen, S T -- Collier, L S -- Krauss, A -- Weber, M J -- CA39076/CA/NCI NIH HHS/ -- GM47332/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Sep 11;281(5383):1668-71.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Microbiology and Cancer Center, University of Virginia Health Sciences Center, Charlottesville, VA 22908, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9733512" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Calcium-Calmodulin-Dependent Protein Kinases/*metabolism ; Carrier Proteins/*metabolism ; Cell Line ; *DNA-Binding Proteins ; Enzyme Activation ; MAP Kinase Kinase 1 ; MAP Kinase Kinase 2 ; Mitogen-Activated Protein Kinase 1 ; Mitogen-Activated Protein Kinase 3 ; *Mitogen-Activated Protein Kinase Kinases ; *Mitogen-Activated Protein Kinases ; Molecular Sequence Data ; Phosphorylation ; Protein-Serine-Threonine Kinases/*metabolism ; Protein-Tyrosine Kinases/*metabolism ; Proto-Oncogene Proteins/metabolism ; Proto-Oncogene Proteins c-raf/metabolism ; Recombinant Fusion Proteins/metabolism ; *Signal Transduction ; *Transcription Factors ; Transcriptional Activation ; Transfection ; ets-Domain Protein Elk-1
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 25
    Publikationsdatum: 1998-06-25
    Beschreibung: Long-term potentiation (LTP) at the Schaffer collateral-CA1 synapse involves interacting signaling components, including calcium (Ca2+)/calmodulin-dependent protein kinase II (CaMKII) and cyclic adenosine monophosphate (cAMP) pathways. Postsynaptic injection of thiophosphorylated inhibitor-1 protein, a specific inhibitor of protein phosphatase-1 (PP1), substituted for cAMP pathway activation in LTP. Stimulation that induced LTP triggered cAMP-dependent phosphorylation of endogenous inhibitor-1 and a decrease in PP1 activity. This stimulation also increased phosphorylation of CaMKII at Thr286 and Ca2+-independent CaMKII activity in a cAMP-dependent manner. The blockade of LTP by a CaMKII inhibitor was not overcome by thiophosphorylated inhibitor-1. Thus, the cAMP pathway uses PP1 to gate CaMKII signaling in LTP.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Blitzer, R D -- Connor, J H -- Brown, G P -- Wong, T -- Shenolikar, S -- Iyengar, R -- Landau, E M -- DK52054/DK/NIDDK NIH HHS/ -- GM54508/GM/NIGMS NIH HHS/ -- NS33646/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1998 Jun 19;280(5371):1940-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Bronx VA Medical Center and Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029, USA. rb2@doc.mssm.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9632393" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors/*metabolism ; *Carrier Proteins ; Cyclic AMP/analogs & derivatives/*metabolism/pharmacology ; Cyclic AMP-Dependent Protein Kinases/metabolism ; Electric Stimulation ; Enzyme Inhibitors/metabolism/pharmacology ; Hippocampus/*metabolism ; In Vitro Techniques ; *Intracellular Signaling Peptides and Proteins ; *Long-Term Potentiation ; Male ; Phosphoprotein Phosphatases/antagonists & inhibitors/*metabolism ; Phosphorylation ; Protein Phosphatase 1 ; RNA-Binding Proteins/metabolism/pharmacology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Synapses/*metabolism ; Thionucleotides/pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 26
    Publikationsdatum: 1998-06-20
    Beschreibung: Stimulation of T lymphocytes results in a rapid increase in intracellular calcium concentration ([Ca2+]i) that parallels the activation of Ca2+-calmodulin-dependent protein kinase IV (CaMKIV), a nuclear enzyme that can phosphorylate and activate the cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB). However, inactivation of CaMKIV occurs despite the sustained increase in [Ca2+]i that is required for T cell activation. A stable and stoichiometric complex of CaMKIV with protein serine-threonine phosphatase 2A (PP2A) was identified in which PP2A dephosphorylates CaMKIV and functions as a negative regulator of CaMKIV signaling. In Jurkat T cells, inhibition of PP2A activity by small t antigen enhanced activation of CREB-mediated transcription by CaMKIV. These findings reveal an intracellular signaling mechanism whereby a protein serine-threonine kinase (CaMKIV) is regulated by a tightly associated protein serine-threonine phosphatase (PP2A).〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Westphal, R S -- Anderson, K A -- Means, A R -- Wadzinski, B E -- GM33976/GM/NIGMS NIH HHS/ -- GM51366/GM/NIGMS NIH HHS/ -- HD07503/HD/NICHD NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1998 May 22;280(5367):1258-61.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9596578" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antigens, Polyomavirus Transforming/metabolism ; Brain/enzymology ; Calcium/metabolism ; Calcium-Calmodulin-Dependent Protein Kinase Type 4 ; Calcium-Calmodulin-Dependent Protein Kinases/genetics/isolation & ; purification/*metabolism ; Calmodulin/metabolism ; Coenzymes/metabolism ; Cyclic AMP Response Element-Binding Protein/metabolism ; Enzyme Activation ; Humans ; Jurkat Cells ; Lymphocyte Activation ; Mutation ; Phosphoprotein Phosphatases/isolation & purification/*metabolism ; Phosphorylation ; Protein Phosphatase 2 ; Rats ; Recombinant Fusion Proteins/metabolism ; *Signal Transduction ; T-Lymphocytes/*enzymology ; Transcription, Genetic
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 27
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-05-23
    Beschreibung: Myotonic dystrophy (DM) is caused by a CTG expansion in the 3' untranslated region of the DM gene. One model of DM pathogenesis suggests that RNAs from the expanded allele create a gain-of-function mutation by the inappropriate binding of proteins to the CUG repeats. Data presented here indicate that the conserved heterogeneous nuclear ribonucleoprotein, CUG-binding protein (CUG-BP), may mediate the trans-dominant effect of the RNA. CUG-BP was found to bind to the human cardiac troponin T (cTNT) pre-messenger RNA and regulate its alternative splicing. Splicing of cTNT was disrupted in DM striated muscle and in normal cells expressing transcripts that contain CUG repeats. Altered expression of genes regulated posttranscriptionally by CUG-BP therefore may contribute to DM pathogenesis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Philips, A V -- Timchenko, L T -- Cooper, T A -- AR 44387/AR/NIAMS NIH HHS/ -- HL45565/HL/NHLBI NIH HHS/ -- New York, N.Y. -- Science. 1998 May 1;280(5364):737-41.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, Baylor College of Medicine, Houston, TX 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9563950" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Alternative Splicing ; CELF1 Protein ; Cell Line ; Cell Nucleus/metabolism ; Exons ; Humans ; Introns ; Muscle, Skeletal/cytology/embryology/metabolism ; Mutation ; Myotonic Dystrophy/*genetics/metabolism ; Myotonin-Protein Kinase ; Phosphorylation ; Protein-Serine-Threonine Kinases/*genetics ; RNA Precursors/metabolism ; RNA, Messenger/*genetics/metabolism ; RNA-Binding Proteins/genetics/*metabolism ; Recombinant Fusion Proteins/metabolism ; Ribonucleoproteins/genetics/*metabolism ; Transcription, Genetic ; Transfection ; *Trinucleotide Repeats ; Troponin/genetics ; Troponin T
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 28
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-05-23
    Beschreibung: Cdc2, the kinase that induces mitosis, is regulated by checkpoints that couple mitosis to the completion of DNA replication and repair. The repair checkpoint kinase Chk1 regulates Cdc25, a phosphatase that activates Cdc2. Effectors of the replication checkpoint evoked by hydroxyurea (HU) are unknown. Treatment of fission yeast with HU stimulated the kinase Cds1, which appears to phosphorylate the kinase Wee1, an inhibitor of Cdc2. The protein kinase Cds1 was also required for a large HU-induced increase in the amount of Mik1, a second inhibitor of Cdc2. HU-induced arrest of cell division was abolished in cds1 chk1 cells. Thus, Cds1 and Chk1 appear to jointly enforce the replication checkpoint.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Boddy, M N -- Furnari, B -- Mondesert, O -- Russell, P -- New York, N.Y. -- Science. 1998 May 8;280(5365):909-12.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Departments of Molecular Biology and Cell Biology, Scripps Research Institute, La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9572736" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): CDC2 Protein Kinase/antagonists & inhibitors/metabolism ; Cell Cycle ; Cell Cycle Proteins/metabolism ; Checkpoint Kinase 2 ; DNA Repair ; *DNA Replication/drug effects ; Hydroxyurea/pharmacology ; *Nuclear Proteins ; Phosphoprotein Phosphatases/metabolism ; Phosphorylation ; Protein Kinases/*metabolism ; *Protein-Serine-Threonine Kinases ; Protein-Tyrosine Kinases/metabolism ; Recombinant Fusion Proteins/metabolism ; S Phase ; Schizosaccharomyces/cytology/enzymology/*metabolism ; *Schizosaccharomyces pombe Proteins ; cdc25 Phosphatases
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 29
    Publikationsdatum: 1998-10-09
    Beschreibung: Phosphoinositide 3-kinases (PI3Ks) activate protein kinase PKB (also termed Akt), and PI3Kgamma activated by heterotrimeric guanosine triphosphate-binding protein can stimulate mitogen-activated protein kinase (MAPK). Exchange of a putative lipid substrate-binding site generated PI3Kgamma proteins with altered or aborted lipid but retained protein kinase activity. Transiently expressed, PI3Kgamma hybrids exhibited wortmannin-sensitive activation of MAPK, whereas a catalytically inactive PI3Kgamma did not. Membrane-targeted PI3Kgamma constitutively produced phosphatidylinositol 3,4, 3,4,5-trisphosphate and activated PKB but not MAPK. Moreover, stimulation of MAPK in response to lysophosphatidic acid was blocked by catalytically inactive PI3Kgamma but not by hybrid PI3Kgammas. Thus, two major signals emerge from PI3Kgamma: phosphoinositides that target PKB and protein phosphorylation that activates MAPK.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Bondeva, T -- Pirola, L -- Bulgarelli-Leva, G -- Rubio, I -- Wetzker, R -- Wymann, M P -- New York, N.Y. -- Science. 1998 Oct 9;282(5387):293-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Research Unit "Molecular Cell Biology," University of Jena, D-07747 Jena, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9765155" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Androstadienes/pharmacology ; Animals ; Binding Sites ; COS Cells ; Calcium-Calmodulin-Dependent Protein Kinases/*metabolism ; Cell Membrane/enzymology ; Cercopithecus aethiops ; Enzyme Activation ; Lysophospholipids/pharmacology ; MAP Kinase Kinase 1 ; Mitogen-Activated Protein Kinase 1 ; *Mitogen-Activated Protein Kinase Kinases ; Molecular Sequence Data ; Myelin Basic Protein/metabolism ; Phosphatidylinositol 3-Kinases/genetics/*metabolism ; Phosphatidylinositol Phosphates/metabolism ; Phosphorylation ; Protein-Serine-Threonine Kinases/metabolism ; Protein-Tyrosine Kinases/metabolism ; Proto-Oncogene Proteins/*metabolism ; Proto-Oncogene Proteins c-akt ; Recombinant Proteins/metabolism ; Signal Transduction ; Transfection
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Publikationsdatum: 1998-06-20
    Beschreibung: MAP kinase phosphatase-3 (MKP-3) dephosphorylates phosphotyrosine and phosphothreonine and inactivates selectively ERK family mitogen-activated protein (MAP) kinases. MKP-3 was activated by direct binding to purified ERK2. Activation was independent of protein kinase activity and required binding of ERK2 to the noncatalytic amino-terminus of MKP-3. Neither the gain-of-function Sevenmaker ERK2 mutant D319N nor c-Jun amino-terminal kinase-stress-activated protein kinase (JNK/SAPK) or p38 MAP kinases bound MKP-3 or caused its catalytic activation. These kinases were also resistant to enzymatic inactivation by MKP-3. Another homologous but nonselective phosphatase, MKP-4, bound and was activated by ERK2, JNK/SAPK, and p38 MAP kinases. Catalytic activation of MAP kinase phosphatases through substrate binding may regulate MAP kinase activation by a large number of receptor systems.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Camps, M -- Nichols, A -- Gillieron, C -- Antonsson, B -- Muda, M -- Chabert, C -- Boschert, U -- Arkinstall, S -- New York, N.Y. -- Science. 1998 May 22;280(5367):1262-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Geneva Biomedical Research Institute, Glaxo Wellcome Research and Development S.A., CH-1228 Plan-les-Ouates, Geneva, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9596579" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; COS Cells ; Calcium-Calmodulin-Dependent Protein Kinases/antagonists & ; inhibitors/genetics/*metabolism ; Catalysis ; Dual Specificity Phosphatase 6 ; Enzyme Activation ; Epidermal Growth Factor/pharmacology ; Mitogen-Activated Protein Kinase 1 ; Mitogen-Activated Protein Kinase 12 ; Mitogen-Activated Protein Kinase 9 ; *Mitogen-Activated Protein Kinases ; Molecular Sequence Data ; Mutation ; Phosphorylation ; Protein Kinases/metabolism ; Protein Tyrosine Phosphatases/genetics/*metabolism ; Recombinant Fusion Proteins/metabolism ; Signal Transduction ; Transfection ; p38 Mitogen-Activated Protein Kinases
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-05-23
    Beschreibung: Xenopus oocytes convert a continuously variable stimulus, the concentration of the maturation-inducing hormone progesterone, into an all-or-none biological response-oocyte maturation. Here evidence is presented that the all-or-none character of the response is generated by the mitogen-activated protein kinase (MAPK) cascade. Analysis of individual oocytes showed that the response of MAPK to progesterone or Mos was equivalent to that of a cooperative enzyme with a Hill coefficient of at least 35, more than 10 times the Hill coefficient for the binding of oxygen to hemoglobin. The response can be accounted for by the intrinsic ultrasensitivity of the oocyte's MAPK cascade and a positive feedback loop in which the cascade is embedded. These findings provide a biochemical rationale for the all-or-none character of this cell fate switch.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ferrell, J E Jr -- Machleder, E M -- CA09302/CA/NCI NIH HHS/ -- GM56383/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 May 8;280(5365):895-8.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular Pharmacology, Stanford University School of Medicine, Stanford, CA 94305-5332, USA. ferrell@cmgm.stanford.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9572732" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Carrier Proteins/pharmacology ; Cell Cycle ; Cycloheximide/pharmacology ; Enzyme Activation ; Feedback ; Kinetics ; Maltose-Binding Proteins ; Mitogen-Activated Protein Kinase 1/*metabolism ; Oocytes/*cytology/drug effects/enzymology/*metabolism ; Phosphorylation ; Progesterone/*pharmacology ; Protein Synthesis Inhibitors/pharmacology ; Proto-Oncogene Proteins c-mos/*pharmacology ; Recombinant Fusion Proteins/pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Publikationsdatum: 1998-12-18
    Beschreibung: cAMP (3',5' cyclic adenosine monophosphate) is a second messenger that in eukaryotic cells induces physiological responses ranging from growth, differentiation, and gene expression to secretion and neurotransmission. Most of these effects have been attributed to the binding of cAMP to cAMP-dependent protein kinase A (PKA). Here, a family of cAMP-binding proteins that are differentially distributed in the mammalian brain and body organs and that exhibit both cAMP-binding and guanine nucleotide exchange factor (GEF) domains is reported. These cAMP-regulated GEFs (cAMP-GEFs) bind cAMP and selectively activate the Ras superfamily guanine nucleotide binding protein Rap1A in a cAMP-dependent but PKA-independent manner. Our findings suggest the need to reformulate concepts of cAMP-mediated signaling to include direct coupling to Ras superfamily signaling.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kawasaki, H -- Springett, G M -- Mochizuki, N -- Toki, S -- Nakaya, M -- Matsuda, M -- Housman, D E -- Graybiel, A M -- P01 CA42063/CA/NCI NIH HHS/ -- P01 HL41484/HL/NHLBI NIH HHS/ -- R01 HD28341/HD/NICHD NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1998 Dec 18;282(5397):2275-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, 02139, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9856955" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 1-Methyl-3-isobutylxanthine/pharmacology ; Adrenal Glands/metabolism ; Adult ; Amino Acid Sequence ; Animals ; Brain/metabolism ; Cell Line ; Colforsin/pharmacology ; Cyclic AMP/*metabolism ; Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors/metabolism ; Fetus/metabolism ; GTP-Binding Proteins/*metabolism ; Gene Expression ; Guanine Nucleotide Exchange Factors ; Humans ; In Situ Hybridization ; Molecular Sequence Data ; Phosphorylation ; Proteins/chemistry/genetics/*metabolism ; Rats ; Second Messenger Systems ; Sequence Deletion ; Signal Transduction ; rap GTP-Binding Proteins ; ras Guanine Nucleotide Exchange Factors
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Publikationsdatum: 1998-01-07
    Beschreibung: A Sonic hedgehog (Shh) response element was identified in the chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) promoter that binds to a factor distinct from Gli, a gene known to mediate Shh signaling. Although this binding activity is specifically stimulated by Shh-N (amino-terminal signaling domain), it can also be unmasked with protein phosphatase treatment in the mouse cell line P19, and induction by Shh-N can be blocked by phosphatase inhibitors. Thus, Shh-N signaling may result in dephosphorylation of a target factor that is required for activation of COUP-TFII-, Islet1-, and Gli response element-dependent gene expression. This finding identifies another step in the Shh-N signaling pathway.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Krishnan, V -- Pereira, F A -- Qiu, Y -- Chen, C H -- Beachy, P A -- Tsai, S Y -- Tsai, M J -- New York, N.Y. -- Science. 1997 Dec 12;278(5345):1947-50.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030 USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9395397" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; COUP Transcription Factor II ; COUP Transcription Factors ; Cell Line ; DNA/metabolism ; DNA-Binding Proteins/*genetics/metabolism ; Enzyme Inhibitors/pharmacology ; *Gene Expression Regulation ; Hedgehog Proteins ; Mice ; Okadaic Acid/pharmacology ; Oxazoles/pharmacology ; Phosphoprotein Phosphatases/antagonists & inhibitors/*metabolism ; Phosphorylation ; Promoter Regions, Genetic ; Proteins/*genetics/*metabolism ; *Receptors, Steroid ; Signal Transduction ; *Trans-Activators ; Transcription Factors/*genetics/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 34
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-02-21
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Downward, J -- New York, N.Y. -- Science. 1998 Jan 30;279(5351):673-4.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Signal Transduction Laboratory, Imperial Cancer Research Fund, London, WC2A 3PX, UK. downward@europa.lif.icnet.uk〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9471728" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3-Phosphoinositide-Dependent Protein Kinases ; Cell Membrane/enzymology ; Cloning, Molecular ; Cytosol/enzymology ; Enzyme Activation ; Models, Chemical ; Phosphatidylinositol Phosphates/metabolism ; Phosphorylation ; Phosphoserine/metabolism ; Phosphothreonine/metabolism ; Protein Conformation ; Protein-Serine-Threonine Kinases/chemistry/genetics/*metabolism ; Proto-Oncogene Proteins/chemistry/*metabolism ; Proto-Oncogene Proteins c-akt ; Ribosomal Protein S6 Kinases/chemistry/*metabolism ; *Signal Transduction
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 35
    Publikationsdatum: 1998-01-07
    Beschreibung: The crystal structure of a soluble, catalytically active form of adenylyl cyclase in a complex with its stimulatory heterotrimeric G protein alpha subunit (Gsalpha) and forskolin was determined to a resolution of 2.3 angstroms. When P-site inhibitors were soaked into native crystals of the complex, the active site of adenylyl cyclase was located and structural elements important for substrate recognition and catalysis were identified. On the basis of these and other structures, a molecular mechanism is proposed for the activation of adenylyl cyclase by Gsalpha.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tesmer, J J -- Sunahara, R K -- Gilman, A G -- Sprang, S R -- DK38828/DK/NIDDK NIH HHS/ -- DK46371/DK/NIDDK NIH HHS/ -- GM34497/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1997 Dec 12;278(5345):1907-16.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute and Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75235-9050, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9417641" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphate/metabolism ; Adenylyl Cyclase Inhibitors ; Adenylyl Cyclases/*chemistry/metabolism ; Amino Acid Sequence ; Binding Sites ; Catalysis ; Colforsin/metabolism ; Crystallization ; Crystallography, X-Ray ; Dimerization ; Enzyme Activation ; GTP-Binding Protein alpha Subunits, Gs/*chemistry/metabolism ; Guanosine 5'-O-(3-Thiotriphosphate)/*chemistry/metabolism ; Ligands ; Models, Molecular ; Molecular Sequence Data ; Mutation ; Phosphorylation ; Protein Conformation ; Protein Structure, Secondary ; Protein Structure, Tertiary
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-01-07
    Beschreibung: Light-regulated translation of chloroplast messenger RNAs (mRNAs) requires trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. Chloroplast polyadenylate-binding protein (cPABP) specifically binds to the 5'-UTR of the psbA mRNA and is essential for translation of this mRNA. A protein disulfide isomerase that is localized to the chloroplast and copurifies with cPABP was shown to modulate the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP through redox potential or adenosine 5'-diphosphate-dependent phosphorylation. This mechanism allows for a simple reversible switch regulating gene expression in the chloroplast.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kim, J -- Mayfield, S P -- GM54659/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1997 Dec 12;278(5345):1954-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cell Biology and The Skaggs Institute for Chemical Biology, The Scripps Research Institute, La Jolla, CA 92037, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9395399" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Diphosphate/metabolism ; Amino Acid Sequence ; Animals ; Binding Sites ; Catalysis ; Chlamydomonas reinhardtii/enzymology/*genetics/metabolism ; Chloroplasts/*genetics/metabolism ; Cloning, Molecular ; Dithiothreitol/pharmacology ; *Gene Expression Regulation ; Glutathione Disulfide/pharmacology ; Molecular Sequence Data ; Oxidation-Reduction ; Phosphorylation ; Photosynthetic Reaction Center Complex Proteins/genetics ; Photosystem II Protein Complex ; *Protein Biosynthesis ; Protein Disulfide-Isomerases/chemistry/genetics/*metabolism ; RNA, Messenger/genetics/metabolism ; RNA-Binding Proteins/*metabolism ; Recombinant Fusion Proteins/metabolism ; Sequence Homology, Amino Acid
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-02-12
    Beschreibung: The process by which extracellular signals are relayed from the plasma membrane to specific intracellular sites is an essential facet of cellular regulation. Many signaling pathways do so by altering the phosphorylation state of tyrosine, serine, or threonine residues of target proteins. Recently, it has become apparent that regulatory mechanisms exist to influence where and when protein kinases and phosphatases are activated in the cell. The role of scaffold, anchoring, and adaptor proteins that contribute to the specificity of signal transduction events by recruiting active enzymes into signaling networks or by placing enzymes close to their substrates is discussed.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pawson, T -- Scott, J D -- GM48231/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1997 Dec 19;278(5346):2075-80.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9405336" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Ligands ; Phospholipids/metabolism ; Phosphoprotein Phosphatases/metabolism ; Phosphoproteins/*metabolism ; Phosphorylation ; Phosphoserine/metabolism ; Phosphothreonine/metabolism ; Phosphotyrosine/metabolism ; Protein-Serine-Threonine Kinases/metabolism ; Protein-Tyrosine Kinases/metabolism ; Proteins/chemistry/*metabolism ; *Signal Transduction ; src Homology Domains
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 38
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-02-12
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pennisi, E -- New York, N.Y. -- Science. 1997 Oct 24;278(5338):573.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9381163" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Alcoholic Intoxication/*enzymology ; Animals ; Central Nervous System Depressants/pharmacology ; Ethanol/*pharmacology ; Hippocampus/cytology/metabolism ; Mice ; Mice, Knockout ; Motor Activity/drug effects ; Neurons/metabolism/physiology ; Phosphorylation ; Protein-Tyrosine Kinases/genetics/*metabolism ; Proto-Oncogene Proteins/genetics/*metabolism ; Proto-Oncogene Proteins c-fyn ; Receptors, N-Methyl-D-Aspartate/metabolism ; Time Factors
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-12-05
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hopkin, K -- New York, N.Y. -- Science. 1998 Nov 6;282(5391):1027,1029-30.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9841444" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Apoptosis ; *Cell Division ; *Genes, Tumor Suppressor ; Humans ; Mice ; Mutation ; Neoplasms/metabolism/*pathology ; PTEN Phosphohydrolase ; Phosphatidylinositol Phosphates/*metabolism ; Phosphoric Monoester Hydrolases/chemistry/genetics/*metabolism ; Phosphorylation ; *Protein-Serine-Threonine Kinases ; Proto-Oncogene Proteins/metabolism ; Proto-Oncogene Proteins c-akt ; Signal Transduction ; Tumor Cells, Cultured ; *Tumor Suppressor Proteins
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    Publikationsdatum: 1998-05-23
    Beschreibung: Anthrax lethal toxin, produced by the bacterium Bacillus anthracis, is the major cause of death in animals infected with anthrax. One component of this toxin, lethal factor (LF), is suspected to be a metalloprotease, but no physiological substrates have been identified. Here it is shown that LF is a protease that cleaves the amino terminus of mitogen-activated protein kinase kinases 1 and 2 (MAPKK1 and MAPKK2) and that this cleavage inactivates MAPKK1 and inhibits the MAPK signal transduction pathway. The identification of a cleavage site for LF may facilitate the development of LF inhibitors.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Duesbery, N S -- Webb, C P -- Leppla, S H -- Gordon, V M -- Klimpel, K R -- Copeland, T D -- Ahn, N G -- Oskarsson, M K -- Fukasawa, K -- Paull, K D -- Vande Woude, G F -- New York, N.Y. -- Science. 1998 May 1;280(5364):734-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Advanced BioScience Laboratories-Basic Research Program, National Cancer Institute-Frederick Cancer Research and Development Center, Post Office Box B, Frederick, MD 21702.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9563949" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; *Antigens, Bacterial ; *Bacillus anthracis/enzymology ; Bacterial Toxins/metabolism/*toxicity ; Binding Sites ; Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors/metabolism ; Cell Line, Transformed ; Enzyme Activation ; Enzyme Inhibitors/toxicity ; Humans ; MAP Kinase Kinase 1 ; MAP Kinase Kinase 2 ; Metalloendopeptidases/metabolism/toxicity ; Mice ; *Mitogen-Activated Protein Kinase Kinases ; Myelin Basic Protein/metabolism ; Oocytes/physiology ; Phosphorylation ; Protein-Serine-Threonine Kinases/*antagonists & ; inhibitors/chemistry/genetics/metabolism ; Protein-Tyrosine Kinases/*antagonists & inhibitors/chemistry/genetics/metabolism ; Recombinant Fusion Proteins/metabolism ; Sequence Deletion ; Signal Transduction ; Xenopus laevis
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-12-04
    Beschreibung: In response to DNA damage and replication blocks, cells prevent cell cycle progression through the control of critical cell cycle regulators. We identified Chk2, the mammalian homolog of the Saccharomyces cerevisiae Rad53 and Schizosaccharomyces pombe Cds1 protein kinases required for the DNA damage and replication checkpoints. Chk2 was rapidly phosphorylated and activated in response to replication blocks and DNA damage; the response to DNA damage occurred in an ataxia telangiectasia mutated (ATM)-dependent manner. In vitro, Chk2 phosphorylated Cdc25C on serine-216, a site known to be involved in negative regulation of Cdc25C. This is the same site phosphorylated by the protein kinase Chk1, which suggests that, in response to DNA damage and DNA replicational stress, Chk1 and Chk2 may phosphorylate Cdc25C to prevent entry into mitosis.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Matsuoka, S -- Huang, M -- Elledge, S J -- GM44664/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Dec 4;282(5395):1893-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9836640" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Ataxia Telangiectasia Mutated Proteins ; *Cell Cycle ; Cell Cycle Proteins/metabolism ; Cell Line ; Checkpoint Kinase 2 ; *DNA Damage ; *DNA Replication ; DNA-Binding Proteins ; Enzyme Activation ; Gamma Rays ; HeLa Cells ; Humans ; Models, Biological ; Molecular Sequence Data ; Phosphorylation ; *Protein Kinases ; Protein-Serine-Threonine Kinases/chemistry/genetics/*metabolism ; Proteins/*metabolism ; Recombinant Fusion Proteins/metabolism ; Saccharomyces cerevisiae/cytology/genetics/growth & development ; Tumor Suppressor Proteins ; Ultraviolet Rays ; *cdc25 Phosphatases
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 42
    Publikationsdatum: 1998-05-09
    Beschreibung: Control of stability of beta-catenin is central in the wnt signaling pathway. Here, the protein conductin was found to form a complex with both beta-catenin and the tumor suppressor gene product adenomatous polyposis coli (APC). Conductin induced beta-catenin degradation, whereas mutants of conductin that were deficient in complex formation stabilized beta-catenin. Fragments of APC that contained a conductin-binding domain also blocked beta-catenin degradation. Thus, conductin is a component of the multiprotein complex that directs beta-catenin to degradation and is located downstream of APC. In Xenopus embryos, conductin interfered with wnt-induced axis formation.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Behrens, J -- Jerchow, B A -- Wurtele, M -- Grimm, J -- Asbrand, C -- Wirtz, R -- Kuhl, M -- Wedlich, D -- Birchmeier, W -- New York, N.Y. -- Science. 1998 Apr 24;280(5363):596-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max Delbruck Center for Molecular Medicine, Robert-Rossle-Strasse 10, 13122 Berlin, Germany.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9554852" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenomatous Polyposis Coli Protein ; Amino Acid Sequence ; Animals ; Axin Protein ; Binding Sites ; Body Patterning ; Calcium-Calmodulin-Dependent Protein Kinases/*metabolism ; Cytoskeletal Proteins/chemistry/genetics/*metabolism ; Glycogen Synthase Kinase 3 ; Humans ; Mice ; Molecular Sequence Data ; Mutation ; Phosphorylation ; Proteins/chemistry ; Proto-Oncogene Proteins/metabolism ; *Repressor Proteins ; Signal Transduction ; *Trans-Activators ; Tumor Cells, Cultured ; Xenopus/embryology ; Xenopus Proteins ; beta Catenin
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-08-15
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Malissen, B -- New York, N.Y. -- Science. 1998 Jul 24;281(5376):528-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Centre d'Immunologie INSERM-CNRS de Marseille-Luminy, Marseille, France. bernardm@ciml.univ-mrs.fr〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9705722" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antigens/immunology ; Antigens, CD3/*metabolism ; Immunoglobulin E/metabolism ; Ligands ; Phosphorylation ; Phosphotyrosine/metabolism ; Protein-Tyrosine Kinases/metabolism ; Rats ; Receptor Aggregation ; Receptor-CD3 Complex, Antigen, T-Cell/metabolism ; Receptors, Antigen, T-Cell/*metabolism ; Receptors, IgE/*metabolism ; Signal Transduction ; T-Lymphocytes/immunology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-02-12
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Maniatis, T -- New York, N.Y. -- Science. 1997 Oct 31;278(5339):818-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138-2092, USA. maniatis@biohp.harvard.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9381193" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Catalysis ; Humans ; I-kappa B Kinase ; Macromolecular Substances ; Membrane Proteins/metabolism ; Multiprotein Complexes ; NF-kappa B/*metabolism ; Phosphorylation ; Protein-Serine-Threonine Kinases/*metabolism ; *Signal Transduction
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 45
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-02-12
    Beschreibung: Abscisic acid (ABA) is the primary hormone that mediates plant responses to stresses such as cold, drought, and salinity. Single-cell microinjection experiments in tomato were used to identify possible intermediates involved in ABA signal transduction. Cyclic ADP-ribose (cADPR) was identified as a signaling molecule in the ABA response and was shown to exert its effects by way of calcium. Bioassay experiments showed that the amounts of cADPR in Arabidopsis thaliana plants increased in response to ABA treatment and before ABA-induced gene expression.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Wu, Y -- Kuzma, J -- Marechal, E -- Graeff, R -- Lee, H C -- Foster, R -- Chua, N H -- HD17484/HD/NICHD NIH HHS/ -- New York, N.Y. -- Science. 1997 Dec 19;278(5346):2126-30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Plant Molecular Biology, Rockefeller University, 1230 York Avenue, New York, NY 10021-6399, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9405349" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Abscisic Acid/*pharmacology ; Adenosine Diphosphate Ribose/*analogs & derivatives/metabolism/pharmacology ; Arabidopsis/genetics/metabolism ; Arabidopsis Proteins ; Calcium/*metabolism/pharmacology ; Cyclic ADP-Ribose ; Egtazic Acid/pharmacology ; GTP-Binding Proteins/physiology ; Gene Expression Regulation, Plant/drug effects ; Genes, Reporter ; Inositol Phosphates/pharmacology ; Lycopersicon esculentum/genetics/metabolism ; Microinjections ; Phosphoprotein Phosphatases/metabolism ; Phosphorylation ; Phytochrome/pharmacology ; Phytochrome A ; Plants/genetics/*metabolism ; Plants, Genetically Modified ; Protein Kinases/metabolism ; *Second Messenger Systems ; *Signal Transduction
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Putney, J W Jr -- New York, N.Y. -- Science. 1998 Jan 9;279(5348):191-2.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Signal Transduction, National Institute of Environmental Health Sciences--National Institutes of Health, Research Triangle Park, NC 27709, USA. putney@niehs.nih.gov〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9446226" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Action Potentials ; Animals ; Brain/metabolism ; Calcium/*metabolism ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinases/*metabolism ; Calmodulin/metabolism ; Endoplasmic Reticulum/metabolism ; Enzyme Activation ; Enzymes, Immobilized ; Mitochondria/metabolism ; Phosphorylation ; *Signal Transduction ; Synaptic Transmission
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-02-21
    Beschreibung: Activation of the protein p70s6k by mitogens leads to increased translation of a family of messenger RNAs that encode essential components of the protein synthetic apparatus. Activation of the kinase requires hierarchical phosphorylation at multiple sites, culminating in the phosphorylation of the threonine in position 229 (Thr229), in the catalytic domain. The homologous site in protein kinase B (PKB), Thr308, has been shown to be phosphorylated by the phosphoinositide-dependent protein kinase PDK1. A regulatory link between p70s6k and PKB was demonstrated, as PDK1 was found to selectively phosphorylate p70s6k at Thr229. More importantly, PDK1 activated p70s6k in vitro and in vivo, whereas the catalytically inactive PDK1 blocked insulin-induced activation of p70s6k.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Pullen, N -- Dennis, P B -- Andjelkovic, M -- Dufner, A -- Kozma, S C -- Hemmings, B A -- Thomas, G -- New York, N.Y. -- Science. 1998 Jan 30;279(5351):707-10.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Friedrich Miescher Institute, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9445476" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 3-Phosphoinositide-Dependent Protein Kinases ; Amino Acid Sequence ; Androstadienes/pharmacology ; Animals ; Binding Sites ; Calcium-Calmodulin-Dependent Protein Kinase Type 4 ; Calcium-Calmodulin-Dependent Protein Kinases/metabolism ; Catalysis ; Cell Line ; Enzyme Activation ; Insulin/pharmacology ; Insulin Antagonists/pharmacology ; Molecular Sequence Data ; Phosphorylation ; Phosphothreonine/metabolism ; Polyenes/pharmacology ; Protein-Serine-Threonine Kinases/*metabolism ; Proto-Oncogene Proteins/metabolism ; Proto-Oncogene Proteins c-akt ; Recombinant Proteins/metabolism ; Ribosomal Protein S6 Kinases/*metabolism ; Sirolimus
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 48
    Publikationsdatum: 1998-12-04
    Beschreibung: Tau proteins aggregate as cytoplasmic inclusions in a number of neurodegenerative diseases, including Alzheimer's disease and hereditary frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17). Over 10 exonic and intronic mutations in the tau gene have been identified in about 20 FTDP-17 families. Analyses of soluble and insoluble tau proteins from brains of FTDP-17 patients indicated that different pathogenic mutations differentially altered distinct biochemical properties and stoichiometry of brain tau isoforms. Functional assays of recombinant tau proteins with different FTDP-17 missense mutations implicated all but one of these mutations in disease pathogenesis by reducing the ability of tau to bind microtubules and promote microtubule assembly.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hong, M -- Zhukareva, V -- Vogelsberg-Ragaglia, V -- Wszolek, Z -- Reed, L -- Miller, B I -- Geschwind, D H -- Bird, T D -- McKeel, D -- Goate, A -- Morris, J C -- Wilhelmsen, K C -- Schellenberg, G D -- Trojanowski, J Q -- Lee, V M -- New York, N.Y. -- Science. 1998 Dec 4;282(5395):1914-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9836646" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Alternative Splicing ; Brain/*metabolism ; Cerebellum/metabolism ; Chromosomes, Human, Pair 17 ; Dementia/*genetics/metabolism ; Frontal Lobe/metabolism ; Humans ; Microtubules/*metabolism ; Mutation ; Mutation, Missense ; Parkinson Disease, Secondary/*genetics/metabolism ; Phosphorylation ; Protein Isoforms/chemistry/genetics/metabolism ; Recombinant Proteins/metabolism ; Solubility ; Syndrome ; tau Proteins/chemistry/*genetics/*metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    Publikationsdatum: 1998-09-11
    Beschreibung: The ATM protein, encoded by the gene responsible for the human genetic disorder ataxia telangiectasia (A-T), regulates several cellular responses to DNA breaks. ATM shares a phosphoinositide 3-kinase-related domain with several proteins, some of them protein kinases. A wortmannin-sensitive protein kinase activity was associated with endogenous or recombinant ATM and was abolished by structural ATM mutations. In vitro substrates included the translation repressor PHAS-I and the p53 protein. ATM phosphorylated p53 in vitro on a single residue, serine-15, which is phosphorylated in vivo in response to DNA damage. This activity was markedly enhanced within minutes after treatment of cells with a radiomimetic drug; the total amount of ATM remained unchanged. Various damage-induced responses may be activated by enhancement of the protein kinase activity of ATM.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Banin, S -- Moyal, L -- Shieh, S -- Taya, Y -- Anderson, C W -- Chessa, L -- Smorodinsky, N I -- Prives, C -- Reiss, Y -- Shiloh, Y -- Ziv, Y -- NS31763/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1998 Sep 11;281(5383):1674-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9733514" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adaptor Proteins, Signal Transducing ; Androstadienes/pharmacology ; Ataxia Telangiectasia/metabolism ; Ataxia Telangiectasia Mutated Proteins ; *Carrier Proteins ; Cell Cycle Proteins ; Cell Line ; *DNA Damage ; DNA-Binding Proteins ; Enzyme Inhibitors/pharmacology ; Humans ; Mutation ; Phosphatidylinositol 3-Kinases/chemistry ; Phosphoproteins/metabolism ; Phosphorylation ; Protein Kinase Inhibitors ; Protein Kinases/chemistry/*metabolism ; *Protein-Serine-Threonine Kinases ; Proteins/antagonists & inhibitors/chemistry/genetics/*metabolism ; Recombinant Proteins/metabolism ; Tumor Cells, Cultured ; Tumor Suppressor Protein p53/*metabolism ; Tumor Suppressor Proteins ; Zinostatin/pharmacology
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 50
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    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-08-01
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Walworth, N C -- New York, N.Y. -- Science. 1998 Jul 10;281(5374):185-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pharmacology, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, Piscataway, NJ 08854-5635, USA. walworna@umdnj.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9687277" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): *Cell Cycle Proteins ; Checkpoint Kinase 2 ; *DNA Damage ; Fungal Proteins/*chemistry/genetics/*metabolism ; *Interphase ; Mutation ; Phosphorylation ; Protein Kinases/chemistry/genetics/metabolism ; *Protein-Serine-Threonine Kinases ; Saccharomyces cerevisiae/cytology/genetics/*metabolism ; *Saccharomyces cerevisiae Proteins ; Ultraviolet Rays
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    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 51
    Publikationsdatum: 1998-08-07
    Beschreibung: Dopaminergic neurons exert a major modulatory effect on the forebrain. Dopamine and adenosine 3',5'-monophosphate-regulated phosphoprotein (32 kilodaltons) (DARPP-32), which is enriched in all neurons that receive a dopaminergic input, is converted in response to dopamine into a potent protein phosphatase inhibitor. Mice generated to contain a targeted disruption of the DARPP-32 gene showed profound deficits in their molecular, electrophysiological, and behavioral responses to dopamine, drugs of abuse, and antipsychotic medication. The results show that DARPP-32 plays a central role in regulating the efficacy of dopaminergic neurotransmission.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Fienberg, A A -- Hiroi, N -- Mermelstein, P G -- Song, W -- Snyder, G L -- Nishi, A -- Cheramy, A -- O'Callaghan, J P -- Miller, D B -- Cole, D G -- Corbett, R -- Haile, C N -- Cooper, D C -- Onn, S P -- Grace, A A -- Ouimet, C C -- White, F J -- Hyman, S E -- Surmeier, D J -- Girault, J -- Nestler, E J -- Greengard, P -- DA 08227/DA/NIDA NIH HHS/ -- DA10044/DA/NIDA NIH HHS/ -- F31 DA005794/DA/NIDA NIH HHS/ -- MH40899/MH/NIMH NIH HHS/ -- New York, N.Y. -- Science. 1998 Aug 7;281(5378):838-42.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University, New York, NY 10021, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9694658" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amphetamines/pharmacology ; Animals ; Behavior, Animal/drug effects ; Calcium/metabolism ; Cocaine/pharmacology ; Corpus Striatum/metabolism ; Cyclic AMP-Dependent Protein Kinases/metabolism ; Dopamine/pharmacology/*physiology ; Dopamine Agents/pharmacology ; Dopamine and cAMP-Regulated Phosphoprotein 32 ; Female ; Gene Expression Regulation ; Gene Targeting ; Genes, fos ; Glutamic Acid/pharmacology ; Male ; Mice ; Mice, Inbred C57BL ; Nerve Tissue Proteins/genetics/*metabolism ; Neurons/*metabolism ; Phosphoprotein Phosphatases/metabolism ; *Phosphoproteins ; Phosphorylation ; Raclopride ; Receptors, Dopamine D1/metabolism ; Receptors, N-Methyl-D-Aspartate/metabolism ; Salicylamides/pharmacology ; Sodium-Potassium-Exchanging ATPase/metabolism ; *Synaptic Transmission ; gamma-Aminobutyric Acid/metabolism
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    Publikationsdatum: 1998-07-10
    Beschreibung: A nonpeptidyl small molecule SB 247464, capable of activating granulocyte-colony-stimulating factor (G-CSF) signal transduction pathways, was identified in a high-throughput assay in cultured cells. Like G-CSF, SB 247464 induced tyrosine phosphorylation of multiple signaling proteins and stimulated primary murine bone marrow cells to form granulocytic colonies in vitro. It also elevated peripheral blood neutrophil counts in mice. The extracellular domain of the murine G-CSF receptor was required for the activity of SB 247464, suggesting that the compound acts by oligomerizing receptor chains. The results indicate that a small molecule can activate a receptor that normally binds a relatively large protein ligand.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Tian, S S -- Lamb, P -- King, A G -- Miller, S G -- Kessler, L -- Luengo, J I -- Averill, L -- Johnson, R K -- Gleason, J G -- Pelus, L M -- Dillon, S B -- Rosen, J -- New York, N.Y. -- Science. 1998 Jul 10;281(5374):257-9.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Transcription Research, Ligand Pharmaceuticals, San Diego, CA 92121, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9657720" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Benzimidazoles/chemistry/metabolism/*pharmacology ; Cell Line ; Colony-Forming Units Assay ; DNA-Binding Proteins/metabolism ; Dimerization ; Female ; Granulocyte Colony-Stimulating Factor/metabolism/pharmacology ; Granulocytes/cytology ; Guanidines/chemistry/metabolism/*pharmacology ; Humans ; Janus Kinase 1 ; Janus Kinase 2 ; Leukocyte Count ; Leukopoiesis ; Mice ; Mice, Inbred C57BL ; *Milk Proteins ; Neutrophils/cytology ; Phosphorylation ; Phosphotyrosine/metabolism ; Protein-Tyrosine Kinases/metabolism ; *Proto-Oncogene Proteins ; Receptors, Granulocyte Colony-Stimulating Factor/chemistry/*metabolism ; Recombinant Fusion Proteins/chemistry/metabolism ; STAT3 Transcription Factor ; STAT5 Transcription Factor ; Signal Transduction/drug effects ; Species Specificity ; Trans-Activators/metabolism ; Transfection ; Tumor Cells, Cultured
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 53
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-01-31
    Beschreibung: The transduction of many cellular stimuli results in oscillations in the intracellular concentration of calcium ions (Ca2+). Although information is thought to be encoded in the frequency of such oscillations, no frequency decoder has been identified. Rapid superfusion of immobilized Ca2+- and calmodulin-dependent protein kinase II (CaM kinase II) in vitro showed that the enzyme can decode the frequency of Ca2+ spikes into distinct amounts of kinase activity. The frequency response of CaM kinase II was modulated by several factors, including the amplitude and duration of individual spikes as well as the subunit composition and previous state of activation of the kinase. These features should provide specificity in the activation of this multifunctional enzyme by distinct cellular stimuli and may underlie its pivotal role in activity-dependent forms of synaptic plasticity.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉De Koninck, P -- Schulman, H -- GM30179/GM/NIGMS NIH HHS/ -- GM40600/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Jan 9;279(5348):227-30.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Neurobiology, Stanford University School of Medicine, Stanford, CA 94305-5401, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9422695" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Base Sequence ; COS Cells ; Calcium/*metabolism/pharmacology ; Calcium-Calmodulin-Dependent Protein Kinase Type 2 ; Calcium-Calmodulin-Dependent Protein Kinases/*metabolism ; Calmodulin/metabolism/pharmacology ; Cercopithecus aethiops ; Enzyme Activation ; Enzymes, Immobilized ; Molecular Sequence Data ; Neuronal Plasticity ; Phosphorylation ; Phosphothreonine/metabolism ; Polyvinyl Chloride ; Recombinant Proteins/metabolism ; *Signal Transduction
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 54
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-07-24
    Beschreibung: The T cell receptor (TCR) alphabeta heterodimer interacts with its ligands with high specificity, but surprisingly low affinity. The role of the zeta component of the murine TCR in contributing to the fidelity of antigen recognition was examined. With sequence-specific phosphotyrosine antibodies, it was found that zeta undergoes a series of ordered phosphorylation events upon TCR engagement. Completion of phosphorylation steps is dependent on the nature of the TCR ligand. Thus, the phosphorylation steps establish thresholds for T cell activation. This study documents the sophisticated molecular events that follow the engagement of a low-affinity receptor.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kersh, E N -- Shaw, A S -- Allen, P M -- New York, N.Y. -- Science. 1998 Jul 24;281(5376):572-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Center for Immunology and Department of Pathology, Washington University School of Medicine, 660 South Euclid Avenue, St. Louis, MO 63110, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9677202" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Animals ; Antigen-Presenting Cells/immunology ; Antigens/immunology ; Antigens, CD3/immunology/*metabolism ; Ligands ; *Lymphocyte Activation ; Membrane Proteins/genetics/immunology/*metabolism ; Mice ; Mice, Transgenic ; Mutation ; Peptides/immunology ; Phosphorylation ; Phosphotyrosine/metabolism ; Protein-Tyrosine Kinases/metabolism ; Receptors, Antigen, T-Cell/genetics/immunology/*metabolism ; Receptors, Antigen, T-Cell, alpha-beta/immunology ; Signal Transduction ; T-Lymphocytes/*immunology ; ZAP-70 Protein-Tyrosine Kinase
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 55
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-07-24
    Beschreibung: The ratio of late to early events stimulated by the mast cell receptor for immunoglobulin E (IgE) correlated with the affinity of a ligand for the receptor-bound IgE. Because excess receptors clustered by a weakly binding ligand could hoard a critical initiating kinase, they prevented the outnumbered clusters engendered by the high-affinity ligands from launching the more complete cascade. A similar mechanism could explain the antagonistic action of some peptides on the activation of T cells.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Torigoe, C -- Inman, J K -- Metzger, H -- New York, N.Y. -- Science. 1998 Jul 24;281(5376):568-72.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Arthritis and Rheumatism Branch, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD 20892-1820, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9677201" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): 2,4-Dinitrophenol/immunology ; Adaptor Proteins, Signal Transducing ; Animals ; Antibody Affinity ; Antigen-Antibody Reactions ; Calcium-Calmodulin-Dependent Protein Kinases/metabolism ; Dansyl Compounds ; Enzyme Precursors/metabolism ; Focal Adhesion Kinase 2 ; Haptens/*immunology/metabolism ; Immunoglobulin E/immunology/*metabolism ; Intracellular Signaling Peptides and Proteins ; Ligands ; Mast Cells/*immunology ; Mitogen-Activated Protein Kinase 1 ; Oncogene Proteins/metabolism ; Phosphorylation ; Phosphotyrosine/metabolism ; Protein-Tyrosine Kinases/metabolism ; Rats ; Receptor Aggregation ; Receptors, IgE/immunology/*metabolism ; Signal Transduction ; T-Lymphocytes/immunology ; Tumor Cells, Cultured
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 56
    Publikationsdatum: 1998-02-07
    Beschreibung: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors in the human digestive tract, but their molecular etiology and cellular origin are unknown. Sequencing of c-kit complementary DNA, which encodes a proto-oncogenic receptor tyrosine kinase (KIT), from five GISTs revealed mutations in the region between the transmembrane and tyrosine kinase domains. All of the corresponding mutant KIT proteins were constitutively activated without the KIT ligand, stem cell factor (SCF). Stable transfection of the mutant c-kit complementary DNAs induced malignant transformation of Ba/F3 murine lymphoid cells, suggesting that the mutations contribute to tumor development. GISTs may originate from the interstitial cells of Cajal (ICCs) because the development of ICCs is dependent on the SCF-KIT interaction and because, like GISTs, these cells express both KIT and CD34.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Hirota, S -- Isozaki, K -- Moriyama, Y -- Hashimoto, K -- Nishida, T -- Ishiguro, S -- Kawano, K -- Hanada, M -- Kurata, A -- Takeda, M -- Muhammad Tunio, G -- Matsuzawa, Y -- Kanakura, Y -- Shinomura, Y -- Kitamura, Y -- New York, N.Y. -- Science. 1998 Jan 23;279(5350):577-80.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Pathology, Osaka University Medical School, Yamada-oka 2-2, Suita 565, Japan.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9438854" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Sequence ; Animals ; Antigens, CD34/analysis ; Cell Line ; Cell Transformation, Neoplastic ; DNA, Complementary ; Digestive System/cytology ; Esophageal Neoplasms/genetics/metabolism/pathology ; Gastrointestinal Neoplasms/chemistry/*genetics/pathology ; Humans ; Intestinal Neoplasms/chemistry/genetics/pathology ; Ligands ; Mice ; Mice, Nude ; Molecular Sequence Data ; *Mutation ; Phosphorylation ; Phosphotyrosine/metabolism ; Proto-Oncogene Proteins c-kit/analysis/chemistry/*genetics/metabolism ; Recombinant Proteins/pharmacology ; Sequence Deletion ; Stem Cell Factor/pharmacology ; Stomach Neoplasms/genetics/metabolism/pathology ; Transfection
    Print ISSN: 0036-8075
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-10-17
    Beschreibung: 13S condensin is a multisubunit protein complex essential for mitotic chromosome condensation in Xenopus egg extracts. Purified 13S condensin introduces positive supercoils into DNA in the presence of topoisomerase I and adenosine triphosphate in vitro. The supercoiling activity of 13Scondensin was regulated by mitosis-specific phosphorylation. Immunodepletion, in vitro phosphorylation, and peptide-mapping experiments indicated that Cdc2 is likely to be the kinase that phosphorylates and activates 13S condensin. Multiple Cdc2 phosphorylation sites are clustered in the carboxyl-terminal domain of the XCAP-D2 (Xenopus chromosome-associated polypeptide D2) subunit. These results suggest that phosphorylation of 13Scondensin by Cdc2 may trigger mitotic chromosome condensation in vitro.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Kimura, K -- Hirano, M -- Kobayashi, R -- Hirano, T -- CA45508/CA/NCI NIH HHS/ -- GM53926/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 1998 Oct 16;282(5388):487-90.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Cold Spring Harbor Laboratory, Post Office Box 100, 1 Bungtown Road, Cold Spring Harbor, NY 11724, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9774278" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphatases/chemistry/*metabolism ; Amino Acid Sequence ; Animals ; CDC2 Protein Kinase/*metabolism ; Chromosomes/chemistry/*metabolism ; DNA, Circular/chemistry/metabolism ; DNA, Superhelical/*chemistry ; DNA-Binding Proteins/chemistry/*metabolism ; Enzyme Activation ; Interphase ; *Mitosis ; Molecular Sequence Data ; Multiprotein Complexes ; Nucleic Acid Conformation ; Peptide Mapping ; Phosphorylation ; Xenopus
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    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 58
    facet.materialart.
    Unbekannt
    American Association for the Advancement of Science (AAAS)
    Publikationsdatum: 1998-12-05
    Beschreibung: 〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Murray, A W -- New York, N.Y. -- Science. 1998 Oct 16;282(5388):425, 427.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Physiology, University of California at San Francisco, San Francisco, CA 94143-0444, USA. amurray@socrates.ucsf.edu〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/9841400" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Adenosine Triphosphatases/chemistry/*metabolism ; Adenosine Triphosphate/metabolism ; Animals ; CDC2 Protein Kinase/metabolism ; Carrier Proteins/metabolism ; *Cell Cycle Proteins ; *Chromosomal Proteins, Non-Histone ; Chromosomes/*metabolism/ultrastructure ; Cyclin B/metabolism ; DNA/chemistry/*metabolism ; DNA, Superhelical/chemistry ; DNA-Binding Proteins/chemistry/*metabolism ; Dosage Compensation, Genetic ; Female ; Interphase ; Male ; *Mitosis ; Multiprotein Complexes ; Nuclear Proteins/metabolism ; Nucleic Acid Conformation ; Phosphorylation ; Xenopus ; *Xenopus Proteins
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Immunogenetics 47 (1998), S. 381-389 
    ISSN: 1432-1211
    Schlagwort(e): Key words H2 ; Histocompatibility ; 2-D PAGE ; Glycan ; Phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Polypeptide phosphorylation and sialylation of the glycan moieties contribute to the charge heterogeneity of the class I major histocompatibility complex glycoproteins. The present study demonstrates that a unique acidic modification unrelated to phosphorylation or glycosylation also affects the charge heterogeneity of the H2-Kk heavy chain of BW5147 lymphoma cells. In vitro cultivation of BW5147 cells results in changes in charge heterogeneity of the H2-Kk heavy chains due to the unique acidic modification. Sequential papain digestion of the 45 000 M r H2-Kk glycoprotein yields a 42 500 M r glycopolypeptide initially, followed by production of a 39 000 M r glycopolypeptide. Results from experiments designed to localize and characterize the novel acidic modification suggest that the modification resides in the segment of the H2-Kk polypeptide located between the two papain cleavage sites. This portion of the polypeptide consists of the transmembrane region and part of the cytoplasmic domain of the H2-Kk heavy chain. At steady state, 25% of the total cell surface H2-Kk possesses this modification. In addition, the modification is mutually exclusive with the phosphorylation of the H2-Kk heavy chain at Ser-333. The possible biological significance of the novel modification of class I antigens is discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 60
    Digitale Medien
    Digitale Medien
    Springer
    Immunogenetics 48 (1998), S. 184-195 
    ISSN: 1432-1211
    Schlagwort(e): Key words β7 integrin gene ; Promoter elements ; TGFβ1 ; Phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  The β7 integrins LPAM-1 (α4β7) and M290 (αEβ7) mediate the homing of lymphocytes to gut-associated lymphoid tissue, and the proposed retention of intraepithelial lymphocytes (IEL), respectively. Here we show that the gut mucosal cytokine TGF- β1 increases the expression of β7 and αE subunit mRNA transcripts and the cell-surface expression of M290 on T cells, and that it decreases the level of α4 integrin transcripts. Induced β7 integrin gene expression was inhibited by the protein tyrosine kinase inhibitor genistein, implicating a role for tyrosine phosphorylation. An analysis of the β7 integrin gene promoter revealed three DNAse I hypersensitivity sites, two of which mapped to the 5′ and 3′ ends of a promoter fragment (nucleotides +690 to +63) that directed both the basal and the TGF-β1-induced expression of a heterologous reporter gene. Deletion analysis identified two TGF-β1 response regions encompassing nucleotides –509 to –398 (TGFBRR1), and –122 to +32 (TGFBRR2). TGFBRR1 interacted with at least five protein complexes, whose binding could be induced with TGF-β1 stimulation and could be antagonized by TGFBRR2 which harbored both similar and distinctive cis-elements. TGFBRR2 interacted specifically with at least two major nuclear protein complexes, whose binding was phosphorylation dependent. These data provide new insights into the mechanism by which TGF-β may switch LPAM-1+ve migrating T cells to express M290, facilitating their retention in the gut.
    Materialart: Digitale Medien
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  • 61
    ISSN: 1432-2048
    Schlagwort(e): Key words: Calmodulin-domain protein kinase ; Nitrate reductase ; Phosphorylation ; 14-3-3 proteins ; Spinacea (nitrate reductase)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract. Spinach (Spinacea oleracea L.) nitrate reductase (NR) is inactivated by phosphorylation on serine-543, followed by binding of the phosphorylated enzyme to 14-3-3 proteins. We purified one of several chromatographically distinct NRserine-543 kinases from spinach leaf extracts, and established by Edman sequencing of 80 amino acid residues that it is a calcium-dependent (calmodulin-domain) protein kinase (CDPK), with peptide sequences very similar to Arabidopsis CDPK6 (accession no. U20623; also known as CPK3). The spinach CDPK was recognized by antibodies raised against Arabidopsis CDPK. Nitrate reductase was phosphorylated at serine-543 by bacterially expressed His-tagged CDPK6, and the phosphorylated NR was inhibited by 14-3-3 proteins. However, the bacterially expressed CDPK6 had a specific activity approx. 200-fold lower than that of the purified spinach enzyme. The physiological control of NR by CDPK is discussed, and the regulatory properties of the purified CDPK are considered with reference to current models for reversible intramolecular binding of the calmodulin-like domain to the autoinhibitory junction of CDPKs.
    Materialart: Digitale Medien
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  • 62
    ISSN: 1432-0878
    Schlagwort(e): Key words: Neurofilaments ; Phosphorylation ; Differentiation ; Immunocytochemistry ; Brain storage ; Fixation ; Microwave ; Human
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract  Neurofilaments, which are exclusively found in nerve cells, are one of the earliest recognizable features of the maturing nervous system. The differential distribution of neurofilament proteins in varying degrees of phosphorylation within a neuron provides the possibility of selectively demonstrating either somata and dendrites or axons. Non-phosphorylated neurofilaments typical of somata and dendrites can be visualized with the aid of monoclonal antibody SMI 311, whereas antibody SMI 312 is directed against highly phosphorylated axonal epitopes of neurofilaments. The maturation of neuronal types, the development of area-specific axonal networks, and the gradients of maturation can thus be demonstrated. Optimal immunostaining with SMI 311 and SMI 312 is achieved when specimens are fixed in a mixture of paraformaldehyde and picric acid for up to 3 days and sections are incubated free-floating. Neurons, with their dendritic domains immunostained by SMI 311 in a Golgi-like manner, can be completely visualized in relatively thick sections. The limitations of Golgi-preparations, such as glia-labeling, artifacts, and the staining of only a small non-representative percentage of existing neurons, are not apparent in SMI preparations, which additionally provide the possibility of selectively staining axonal networks. The results achieved in normal fetal brain provide the basis for studies of developmental disturbances.
    Materialart: Digitale Medien
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  • 63
    ISSN: 1573-5028
    Schlagwort(e): chlorophyll a/b protein ; CP29 ; Phosphorylation ; Photosystem II ; cold stress
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The CP29 subunit of Photosystem II is reversibly phosphorylated in Zea mays upon exposure to high light in the cold (Bergantino et al., J Biol Chem 270 (1995) 8474–8481). This phenomenon was previously proposed to be restricted to C4 plants. We present the complete sequence of the CP29 protein, deduced from a maize Lhcb4 cDNA clone, and its comparison with the previously known Lhcb4 sequences of two C3 plants: Hordeum vulgare and Arabidopsis thaliana. Despite the relatively low degree of homology in their amino-terminal region, i.e. the part of the molecule which is phosphorylated in maize, the three polypeptides conserve consensus sequences for the site of phosphorylation. We proved by immunoblotting and 33P-labelling that the same post-translational modification occurs in barley. Being thus common to C3 and C4 plant species, the phosphorylation of this minor antenna complex of Photosystem II appears now as a widespread phenomenon, possibly part of the phosphorylation cascade which signals the redox status of the plastoquinone to the nuclear transcription apparatus. Arabidopsis plants do not show phosphorylation of CP29 in the same conditions, but other low-molecular-weight phosphoproteins, whose role need to be elucidated, become evident.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    ISSN: 1617-4623
    Schlagwort(e): Key words Cold ; Phosphorylation ; Promoter ; Transcription ; Wheat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The Wcs120 gene encodes a highly abundant protein which appears to play an important role during cold acclimation of wheat. To understand the regulatory mechanism controlling its expression at low temperature, the promoter region has been characterized. Electrophoretic mobility shift assays using short promoter fragments revealed the presence in nuclear extracts from non-acclimated (NA) plants of multiple DNA-binding proteins which interact with several elements. In contrast, no DNA-binding activity was observed in the nuclear extracts from cold-acclimated (CA) plants. In vitro dephosphorylation of these CA nuclear extracts with alkaline phosphatase restored the binding activity. Moreover, okadaic acid (a potent phosphatase inhibitor) markedly stimulated the in vivo accumulation of the WCS120 family of proteins. This suggests that protein phosphatases PP1 and/or PP2A negatively regulate the expression of the Wcs120 gene. In addition, both Ca2+-dependent and Ca2+-independent kinase activities were found to be significantly higher in the CA nuclear extracts. Western analysis using antibodies directed against protein kinase C (PKC) isoforms showed that a PKCγ homolog (84 kDa) is selectively translocated into the nucleus in response to low temperature. Taken together, our results suggest that, in vivo, the expression of the Wcs120 gene may be regulated by nuclear factors whose binding activity is modulated by a phosphorylation/dephosphorylation mechanism.
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  • 65
    ISSN: 1434-193X
    Schlagwort(e): Photocycloaddition ; Ring opening ; Oxetanes ; 1,2-Diols ; Alkyldealkoxylation ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The ring opening of 3-isopropyl-2-phenyl-3-oxetanol (2a) by various nucleophiles has been studied. In the presence of BF3 as a Lewis acid, a clean reaction at the less substituted C-4 position was observed and the corresponding 1,2-diols 6-11 and 21-23 were isolated in diastereomerically pure form (47-97% yield). Alkyl-, aryl-, alkynyl- and alkenyllithium compounds proved to be suitable carbon nucleophiles. Deprotonated thiols were used as sulfur nucleophiles. An alkoxide derived from benzyl alcohol and an amide derived from benzylamine reacted less readily under these conditions, yielding the 1,2,3-trifunctional compounds 24 (42% yield) and 26 (54% yield). Other 2-phenyl-3-oxetanols such as 2b and 2c can also be employed as electrophiles, whereas 2-anisyl derivatives preferentially undergo rearrangement reactions, as exemplified by the conversion of oxetane 16 to the hydroxy ketone 17 (84% yield). The superior behaviour of 3-oxetanols as compared to their silyl derivatives in reactions with nucleophiles became evident from the reaction of 3-silyloxyoxetane 1a with alkyllithium reagents. A β elimination occurred upon treatment with nBuLi, which, after pericyclic ring opening and addition of nBuLi, yielded the allylic alcohol 20.
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  • 66
    ISSN: 1434-193X
    Schlagwort(e): Azoalkanes ; DBO ; Fluorescence quenching ; Exciplexes ; Hydrogen transfer ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The fluorescence of the DBO derivatives 1-3 is efficiently quenched by olefins and arenes, exciplex formation and hydrogen transfer operate as quenching mechanisms. The electron-accepting ester groups in the azoalkanes 1-3 promote significantly more effective quenching compared to the parent DBO. Steric hindrance accounts for the differences in the quenching efficiencies, but electronic effects dominate
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  • 67
    ISSN: 1434-193X
    Schlagwort(e): Mannich bases ; γ-Amino alcohols ; Grob fragmentation ; (Z)-Alkenes ; Oxetanes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Quaternized γ-amino alcohols 5 derived from ternary iminium salts 2 are stereospecifically converted into both unsaturated aldehydes/ketones 6 with a (Z)-C—C double bond in a Grob-type fragmentation and highly functionalized oxetanes 7 by intramolecular substitution.
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  • 68
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2201-2207 
    ISSN: 1434-193X
    Schlagwort(e): Antibiotics ; Asymmetric synthesis ; β-Lactams ; Michael additions ; Multicomponent reactions ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Lithium dialkylcuprates react either in a sequential one-pot or in a domino “three-component” fashion with chiral Michael acceptors, like Oppolzer's N-enoyl-2,10-camphorsultams 7 and 11 or ‘Evans’ N-enoyl-4-phenyl-1,3-oxazolidin-2-ones 8 and 13, and N-(methoxycarbonylmethylidene)(4-methoxyphenyl)amine 9 to afford the corresponding cis-3-alkyl-4-methoxycarbonyl-1-(4-methoxyphenyl)azetidin-2-ones 10, 14-15 in overall yields of 40-67% and enantiomeric excesses of 91-99%.
    Materialart: Digitale Medien
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  • 69
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2229-2235 
    ISSN: 1434-193X
    Schlagwort(e): 3-Nitro-ω-benzylideneacetophenone ; Carbanions ; Michael addition ; Intramolecular vicarious nucleophilic substitution of hydrogen ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 3-Nitro-ω-benzylideneacetophenone (1) reacts with carbanions containing leaving groups to give addition products to the electrophilic side chain. As a result of conjugated addition and subsequent intramolecular vicarious nucleophilic substitution of hydrogen (VNS) in the nitroaromatic ring of 1 in the position para to the nitro group, 4-cyano-7-nitro-3-phenyl-1,2,3,4-tetrahydronaphthalen-1-one and 4-cyano-7-nitro-3-phenylnaphth-1-ol are obtained. Smooth intramolecular VNS in the position para to the nitro group was observed for 4-chloro-1-(3-nitrophenyl)-3-phenyl-4-(p-tosyl)butanol.
    Materialart: Digitale Medien
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  • 70
    ISSN: 1434-193X
    Schlagwort(e): Conformation analysis ; Electrochemistry ; Nitrogen heterocycles ; Dimerization ; Mechanism ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: In aqueous media the one-electron reduction of the title compounds on a mercury pool generally gives rise to three dimers, which are distinguishable by HPL chromatography. From spectroscopic analyses it has been possible to propose a structure for these conformers and their stability has been studied. Two conformers are unstable, yielding the third conformer. A mechanism is proposed for this transformation.
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  • 71
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 837-846 
    ISSN: 1434-193X
    Schlagwort(e): AZT ; cycloSal-pro-nucleotide ; Prodrugs ; Nucleotide delivery ; HIV chemotherapy ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The application of our cycloSaligenyl- (cycloSal) pronucleotide concept to the approved anti-HIV dideoxynucleoside 3′-azido-3′-deoxythymidine AZT (1) is reported. This pro-nucleotide concept has been designed to deliver the corresponding 3′-azido-3′-deoxythymidine monophosphate AZTMP (2) by selective chemical hydrolysis from the lipophilic precursors cycloSal-AZTMP 4a-h. All derivatives 4a-h were synthesized using differently substituted salicyl alcohols 7a-h as starting materials. In hydrolysis studies, compounds 4 decomposed selectively releasing AZTMP (2) and the salicyl alcohols 7 following the designed tandem reaction. Furthermore, due to the electronic properties introduced by substituents, the half-lives of the triesters 4 could be ajusted over a wide range. Phosphotriesters 4 exhibited considerable biological activity in HIV-1 and HIV-2 infected wild-type human T-lymphocyte (CEM/O) cells, whereas, contrary to our expectations, nearly all activity was lost in HIV-2 infected thymidine-kinase-deficient CEM cells.
    Materialart: Digitale Medien
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  • 72
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 853-859 
    ISSN: 1434-193X
    Schlagwort(e): N-Alkylation ; Diketopiperazine building block ; Peptidomimetics ; RGD analogues ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: As a new scaffold for peptidomimetic synthesis, a highly constrained bifunctional diketopiperazine, 4, has been prepared by smooth N-alkylation with tert-butyl bromoacetate. As a first application, we describe herein the synthesis of new peptidomimetics of the Arg-Gly-Asp (RGD) sequence. The product 30, which shows a selective platelet-aggregation inhibiting activity, can be used as a lead for the preparation of more potent products.
    Materialart: Digitale Medien
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  • 73
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 871-876 
    ISSN: 1434-193X
    Schlagwort(e): Dioxirane ; Homolysis, induced ; Aminoxyl ; Oxidation ; Spin-trapping ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: In the reactions of dimethyldioxirane (1a) and methyl(trifluoromethyl)dioxirane (1b) with 2,2,6,6-tetramethylpiperidinyl-1-oxyl (2) (TEMPO) in acetone, the corresponding methoxyamine 1-methoxy-2,2,6,6-tetramethylpiperidine (5) is produced in ≥98% yield, both in air and under N2, and in the absence or presence of a hydrocarbon (adamantane). Kinetic experiments show that aminoxyl 2 triggers the radical decomposition of the dioxirane, in addition to scavenging methyl radicals derived therefrom. The reactions of an aminoxyl less prone to oxidation, namely 1,2-dihydro-2-methyl-2-phenyl-3H-indol-3-one-1-oxyl (4), with dioxiranes 1a and 1b in acetone have also been studied. In these cases, not only is the corresponding methoxyamine 8a produced (yield 12-16%), but quinoneimine-N-oxides 10 (yield 12-21%) and 11 (yield 18-19%) are also formed. Furthermore, significant amounts (8-14%) of the amine 9 (the product of deoxygenation of 4) can be isolated. These observations provide useful information concerning the free-radical mechanism that follows the initial attack by the aminoxyl at the dioxirane.
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  • 74
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2373-2377 
    ISSN: 1434-193X
    Schlagwort(e): Charge-transfer fluorescence ; Fluorogenic probe ; Fluorescence labelling ; Maleimide group ; Solvatochromism ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Structural modification of the highly fluorescent donor-bridge-acceptor molecule “Fluoroprobe” (FP) is shown to extend the excitation window to longer wavelengths. The resulting “Fluorotrope” (FT) shows appreciable absorption in the 350-420-nm range, so that visible (blue) light can be used for excitation. Further functionalization with a maleimide group results in the novel fluorogenic reagent MaleimidoFluorotrope (MFT) which yields fluorescent adducts with amines, thiols and other reactive groups that add to the double bond of the maleimide. The fluorescence wavelength of these adducts is extremely sensitive to the polarity and mobility of the medium.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 75
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2379-2387 
    ISSN: 1434-193X
    Schlagwort(e): β-Peptides ; Polylithiation of peptides ; Li-enolates of peptides ; Back-bone alkylation of β-peptides ; Diastereoselective alkylation of β-peptide enolates ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A series of N-Boc-protected β-tripeptide derivatives with or without N-methyl groups and with free or Me-ester-protected C terminus has been prepared (8-14, 16, 17). As with α-peptides (→ A), the β-peptide derivatives can be polylithiated (→ B, C). No epimerization of stereogenic centers and no β elimination (exception 17 → 24) is observed upon treatment with bases as strong as tBuLi. The C terminal ester Li-enolate moiety of tetralithio β-tripeptides (cf. C) can be selectively alkylated with methyl, benzyl and allyl halides, and with tert-butyl bromoacetate in yields ranging from 35-80% (8 → 18, 14 → 20-23).
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  • 76
    ISSN: 1434-193X
    Schlagwort(e): Natural products ; Steroids ; Chenodeoxycholic acid ; Brassinosteroid analogues ; Biological activity ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis and spectroscopic characterization of two new bioactive analogues of brassinosteroids with a 24-hydroxylated cholanic side chain, an A/B ring cis-junction and oxygenated functions in C-7 is described.
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  • 77
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2409-2416 
    ISSN: 1434-193X
    Schlagwort(e): Sulfur heterocycles ; Rearrangements ; Reductions ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The syntheses of 1,2-benzodithiino[5,4,3-cde][1,2]benzodithiin-2,7-diamine (1) and dithio-bridged benzidine 2 have been achieved. The starting material for the synthesis of 1 was 1,3-diiodo-5-nitrobenzene (15) which was transformed by conventional means into 1,2-bis[3,5-bis(ethylthio)phenyl]diazane (19). The benzidine rearrangement of 19 in the presence of HBF4 at -30 °C yielded 4,4′-diamino-2,2′,6,6′-tetraethylthiobiphenyl (20) in 50 % yield. Treatment of 20 with sodium in ammonia and work-up in the presence of air yielded 1. The latter compound could be reduced with LiAlH4 to the tetrathiol 20a. The starting material for the preparation of 2 was 3-chloro-1-iodo-5-nitrobenzene (23), a side product of the preparation of 15. It was transformed analogously to the preparation of 1 into 1,2-bis(3-ethylthiophenyl)diazane (28). The benzidine rearrangement of 28 in presence of HBF4 at -30 °C afforded 4,4′-diamino-2,2′-bis(ethylthio)biphenyl (29) in 49 % yield. Treatment of 29 with sodium in ammonia and work-up under aerobic conditions yielded 2. Quantitative reduction of 2 to the thiol 29a could be achieved with LiAlH4. The reversible electrochemical reduction of 1 on unmodified glassy carbon electrodes leads to a product to which the structure of 3 was assigned.
    Zusätzliches Material: 5 Ill.
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  • 78
    ISSN: 1434-193X
    Schlagwort(e): N-Heterocycles ; Porphyrins ; Radical cations ; N-Dealkylation ; Stereoelectronic effects ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Evidence for a stereoelectronic inhibition of deprotonation of the radical cation of N-benzylpiperidine is presented. This stereoelectronic effect, which is due to the cyclic structure of the precursor, provides a tool to differentiate hydrogen-atom- versus electron-transfer routes in the biomimetic oxidative N-dealkylation of tertiary amines: the electron-transfer route appears to be the operating mechanism.
    Zusätzliches Material: 1 Ill.
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  • 79
    ISSN: 1434-193X
    Schlagwort(e): Colchicine ; 10-Ethylthiocolchicide, diene properties of ; π-Facial diastereoselectivity ; Consecutive [4+2],[3+2] cycloadditions ; Atropisomerism ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Cycloaddition reactions of the facially dissymmetric diene moiety of (-)-(M,7S)-colchicine (5) and (-)-(M,7S)-10-ethylthiocolchicide (9) to various alkynes have been studied. With 5 and the dienophilic benzyne (3), dimethyl acetylenedicarboxylate (DMAD) (4) and cyclooctyne (6) as starting materials all cycloadditions could be realized with high regioselectivity at the 8,12-positions of the alkaloid. The approach of the dienophiles preferentially occurred toward the syn π-face of the diene. In contrast to the cycloaddition mode of 5 the ethylthiocolchicide 9 surprisingly reacted in a different manner. With benzyne as starting material a novel [3+2] cycloaddition of the thioenol ether moiety of 9 towards the dipolarophilic benzyne is supposed, affording the unexpected colchicide 10 after [1,5]H shift of the primarily formed cycloadduct followed by cleavage of the C-S linkage. With DMAD (4) and cyclooctyne (6) the reaction course is more complex. In a consecutive [4+2]/[3+2] cycloaddition (or vice versa) followed by a thermally induced cycloreversion of a not identified intermediate DMAD (4) gives rise to the polycyclic thiophene derivative 13 and the novel allocolchicinoid 14. In a similar way cyclooctyne (6) yielded three products, the thiophene-annulated homobarrelenones 18 and 19 and the tetracyclic allocolchicinoid 21. The structures of the novel colchicine derivatives were assigned on the basis of spectral data, those of the cycloadducts 1 and 19 were verified by X-ray crystallography. For the unprecedented formation of the various allocolchicinoids by consecutive [4+2]/[3+2] cycloadditions plausible reaction pathways are suggested, as far as possible. In addition the inhibitory effects on the tubulin polymerization reaction in vitro of 10, 14, and 21 are reported.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 80
    ISSN: 1434-193X
    Schlagwort(e): Paclitaxel (Taxol®) ; Paclitaxel CD-ring ; High-pressure Diels-Alder reactions ; Furan cycloadditions ; Ether cleavage in 7-oxabicyclo[2.2.1]heptanes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The high-pressure promoted Diels-Alder reactions between several furans and citraconic anhydride have been studied and the cycloadducts obtained have been explored in new straightforward routes to the CD-ring fragment of paclitaxel. The reaction between furan and citraconic anhydride afforded the exo cycloadduct diastereoselectively, whereas a variety of 2-substituted furans afforded approximate 1:1 mixtures of exo regioisomers. Separation of both regioisomers was accomplished after either diastereoselective esterification or regioselective reduction of the anhydride function. Ether cleavage of the bicyclic compounds by either high-pressure promoted ether cleavage or Boord elimination afforded several potential CD-ring precursors which can be used in the total synthesis of paclitaxel analogues.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 81
    ISSN: 1434-193X
    Schlagwort(e): Camphoracetyl chloride ; Lactols, fused ; Lactones, fused ; Pseudoacid chlorides ; Reagents, stereoselective ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: endo-Fused lactone 3 was obtained in high yield from the camphoracetic acid 2 with thionyl chloride and a subsequent reduction of intermediate 5 with tributyltin hydride. The structure of 5 was elaborated and some aspects of the mechanism of its formation and reactivity were investigated. Lactone 3 serves as key intermediate for lactol 1 which is a useful reagent in racemate resolution and asymmetric synthesis.
    Zusätzliches Material: 1 Ill.
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  • 82
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2609-2615 
    ISSN: 1434-193X
    Schlagwort(e): Supramolecular chemistry ; Domino reactions ; Bipyridines ; 1,x-Cyclohexanediones ; Mannich bases ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A one-pot reaction using 1,x-cyclohexanediones, a Mannich base (or its hydrochloride), and ammonium acetate delivers novel pyridines or 3,3′-bridged bipyridine compounds 8, 16, 18, 20, and 22. This strategy offers a great flexibility in the design of new building blocks, e.g. in supramolecular chemistry and underlines the efficiency of domino reactions.
    Zusätzliches Material: 1 Ill.
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  • 83
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2603-2607 
    ISSN: 1434-193X
    Schlagwort(e): Fluoro analogs of vitamin A ; Horner-Wittig reaction ; Fluoroisoprenoid building blocks ; Stereoselectivity ; Hydrolysis of chlorofluorocyclopropanes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: An improved method for the preparation of ethyl 2-fluoro-3-methyl-2-butenoate (3) is described. The two stereoisomers [(E)-4 and (Z)-4] obtained after γ-bromination can be separated and can be individually converted into the corresponding diethyl phosphonates. The PO-ylides generated by α-deprotonation of the latter lose their stereochemical integrity by rapid torsional equilibration of the ester tail. Thus, Horner-Wittig reactions accomplished with benzaldehyde and (Z)- or (E)-(β-ionylidene)-acetaldehyde lead inevitably to stereorandomization at the terminal, ethoxycarbonyl-bearing double bond affording (E)- and (Z)-isomers in 50:50 to 15:85 ratios, depending on the reaction conditions. The new double bond, however, is formed with perfect trans-selectivity.
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  • 84
    ISSN: 1434-193X
    Schlagwort(e): Alkaloids ; Total synthesis/Pumiliotoxin ; PTX-C ; PTX isomers ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A method is described for the synthesis of pumiliotoxin C (1a) and related stereoisomeric compounds 1c-1f. Starting from (+)- or (-)-3-methylcyclohexanone (6a,b), the oxo esters 7a and 7b were prepared. Condensation with (+)- or (-)-3-aminohexanol (8a,b) gave the stereoisomeric 3-aminoacrylates 9a, 9b and 9c. The hydroxy group of the amino-acrylates was transformed into bromide using the tosylate method. Cyclization of the bromides led to unsaturated quinoline ring systems. Finally, decarboxylation and catalytic hydrogenation gave the different cis- and trans-fused stereoisomeric alkaloids of the pumiliotoxin C type. The structures were verified by X-ray analysis.
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  • 85
    ISSN: 1434-193X
    Schlagwort(e): Lawesson's reagent ; Thiolation of cyclic ketones ; Anchimeric effect ; cis-Bicyclo[3.3.0]octane-3,7-diones ; 9-Thiatricyclo[3.3.1.03,7]nonane ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A simple and efficient approach to the 9-thiatricyclo[3.3.1.03,7]nonane ring system (5) has been found by treating cis-bicyclo[3.3.0]octane-3,7-diones (1) with Lawesson's reagent or phosphorus pentasulfide. When dione 1 is treated with Lawesson's reagent tetramethyl 3(4aH)oxo-1,4-dihydrophenanthro[9,10-a]pentalene-1,2,4,4a-tetracarboxylate (6) is obtained as a by-product as shown by X-ray structural analysis.
    Zusätzliches Material: 1 Ill.
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  • 86
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2667-2672 
    ISSN: 1434-193X
    Schlagwort(e): Pyrazolidin-3-ones ; Optical activity ; Asymmetric synthesis ; Ring transformation ; Hydrazines ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Enantiopure α-alkylidenelactones 7 were prepared by a Wittig reaction from α-bromolactones 4 and chiral aldehydes 6. Compounds 7 react with hydrazines 9 by stereoselective Michael-like addition and ring-chain transformation affording optically active 4-(ω-hydroxyalkyl)pyrazolidin-3-ones 11.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 87
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2673-2676 
    ISSN: 1434-193X
    Schlagwort(e): Aromatic aldehydes ; Pinacol coupling ; Radical reactions ; Reagent control ; Titanium ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A novel concept for conductingtransition-metal-catalyzed radical reactions that allows highly diastereoselective titanocene-catalyzed pinacol couplings is described.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
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  • 88
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2677-2682 
    ISSN: 1434-193X
    Schlagwort(e): Terpenoid lactones ; Antifeedants ; Limonene ; Claisen rearrangement ; Iodolactonization ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Four enantiomeric pairs of spirolactones were obtained in a four step synthesis from (+) and (-) limonene. The Claisen rearrangement and iodolactonization were the key steps of the syntheses presented. The structures of products were confirmed by X-ray crystallography of 11, 18b, and 19.
    Zusätzliches Material: 3 Ill.
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  • 89
    ISSN: 1434-193X
    Schlagwort(e): Phosphole ; Phosphanorbornadiene ; Stille cross-coupling ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The reaction of alkynylstannanes with 1-phenyl-3,4-dimethylphosphole at 150 °C affords the corresponding 2-stannyl-1-phosphanorbornadienes (2a, b), in fair yield. Oxidation under mild conditions affords the corresponding phosphane oxides (3a, b), whereas more drastic conditions (H2O2, 15% in toluene at 80 °C) induce the oxidative cleavage of the P-CH2 bond of the bridge to give a bicyclic phosphinate such as 4. Treatement of 4 by iodine leads to a tin → iodine exchange. The X-ray crystal structure analysis of the resulting 1-phospha-2-oxabicyclo[2.2.2]octa-5,7-diene 1-oxide confirms the functionalisation at the α-position and the relief of ring strain taking place upon insertion of oxygen into the P-CH2 bond of the norbornadiene. The 2-stannyl-1-phosphanorbornadiene 1-oxides (3a, b) readily undergo tin → iodine exchange. The resulting 2-iodo derivatives (6a, b) can be cross-coupled with 2-furyl-, 2-thienyl-, 2-pyrrolyl-, phenylethynyl-, and vinyl-tributylstannanes to give the corresponding 2-functional 1-phosphanorbornadiene 1-oxides in excellent yields (80-95%)
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 90
    ISSN: 1434-193X
    Schlagwort(e): Asymmetric synthesis ; Density functional calculations ; Cycloadditions ; Dihydropyrans ; Enantioselective oxidations ; Sulfur heterocycles ; Sulfoxides ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The 4-benzylidene-3-oxo[1,3]oxathiolan-5-ones 13-15, which were derived from the 3-oxo[1,3]oxathiolan-5-ones 9-11 by Knoevenagel condensation with the aldehydes 12, cyclize in an intramolecular hetero Diels-Alder reaction with high yield and excellent endo/exo as well as induced diastereoselectivity to give the hetero Diels-Alder adducts 16-18. The preferred formation of the Knoevenagel products 13-15 with a (Z) configuration was predicted with DFT calculations (B3LYP-6-311+G*) using the model systems 28 and 29. In addition B3LYP-6-31G*/sB3LYP/3-21G(*) calculations on transition structures for the hetero Diels-Alder reaction of 29 and 30 allowed a good correlation with the experimental results, which show that an endo attack of the dienophile syn to the S-O group in 13-15 leads to the main products.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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  • 91
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2759-2767 
    ISSN: 1434-193X
    Schlagwort(e): Phosphorus phthalocyanines ; Triazatetrabenzcorroles ; Dihydroxyphosphorus(V) phthalocyanine hydroxides ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The previously reported reaction of phthalocyanines [H2(pc)] with PBr3, which was claimed to give a phosphorus(III) phthalocyanine “(PcPIII)”, has been reinvestigated in detail with both unsubstituted and alkyl-substituted phthalocyanines, 1-4. The products exhibit unusual electronic and mass spectra compared to normal phthalocyanines and have been identified as oxophosphorus(V) triazatetrabenzcorroles 5-8. The corresponding dihydroxyphosphorus(V) phthalocyanine hydroxides 9-12 have also been synthesized for the first time by insertion of phosphorus(V) into phthalocyanines and have been characterized in detail. The different reactivities of PBr3 and POX3 (X = Cl, Br) toward phthalocyanines are discussed.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
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  • 92
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 2769-2773 
    ISSN: 1434-193X
    Schlagwort(e): Rubicenes ; Cyclization ; Polycyclic aromatic hydrocarbons ; Arenes ; Synthetic methods ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of novel disubstituted rubicenes 1a-k is described. Starting from 1,5-dichloroanthraquinone and aryllithium reagents 3, the diol adducts 4 are reduced and the resulting diarylanthracenes 5 are cyclized to afford the title compounds in fair to good overall yield.
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  • 93
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 37-41 
    ISSN: 1434-1948
    Schlagwort(e): Tripodal P ligands ; Rhodium ; Water-soluble complexes ; Immobilization ; Biphasic hydroformylation ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of the water-soluble tripodal phosphane ligand cis,cis-1,3,5-(PPh2)3-1,3,5-[CH2(OCH2CH2)xOCH3]C6H6 (x = 30-160) (5) has been achieved in a four-step reaction sequence. The alcohol Mo(CO)3[cis,cis-1,3,5-(PPh2)3-1,3,5-(CH2OH)3C6H6] (1) is converted to the corresponding alcoholate 2, which forms the polyethylene glycol derivative 3 in a polyaddition reaction with oxirane. After methylation of the end groups of 3, the ligand 5 is obtained by a combined photochemical/oxidative demolybdenation reaction. The water-soluble tripodal phosphane 5 and the methoxymethyl functionalized tripodal ligand 6 react with Rh(PPh3)3(CO)H to form the water-soluble and water-insoluble rhodium carbonyl hydrido complexes 5a and 6a, respectively. The catalytic activity of the rhodium complex 5a in the hydroformylation of 1-hexene was found to be comparable in a single-phase system (1-hexene/methanol) with that in the biphasic system (1-hexene/water). Only traces of alcohol were found, which demonstrates that the catalyst 5a displays higher selectivity in hydroformylation than in hydrogenation.
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  • 94
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 55-59 
    ISSN: 1434-1948
    Schlagwort(e): Arsaalkenes ; Arsenic ligands ; Carbonyl complexes ; Chromium ; Iron ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Reaction of equimolar amounts of the metalloarsaalkene [(η5-C5Me5)(CO)2FeAs=C(NMe2)2] (1) with the carbonyl complexes [Ni(CO)4], [Fe2(CO)9], and [{(Z)-cyclooctene}Cr(CO)5], respectively, affords the adducts [(η5-C5Me5)(CO)2FeAs{M(CO)n}=C(NMe2)2] with [M(CO)n] = [Ni(CO)3] (2); [Fe(CO)4] (3), and [Cr(CO)5] (4). These feature η1 coordination of the arsaalkene ligand via the arsenic atom. The molecular structures of the complexes 3 and 4 have been determined by X-ray diffraction analyses.
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  • 95
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 155-157 
    ISSN: 1434-1948
    Schlagwort(e): Bite angle ; Catalysis ; P ligands ; Palladium ; Cross-coupling ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The effect of the natural bite angle (βn) of diphosphane ligands on catalyst selectivity and activity in the palladium-catalyzed cross-coupling of sec-butyl magnesium chloride with bromobenzene was investigated. The calculated natural bite angles range from 78° for dppe (1,2-bisdiphenylphosphanoethane) to 110° for Xantphos. The natural bite angle of diphosphane ligands has a large effect on catalyst selectivity and activity. Both rate and selectivity of the cross-coupling reaction increase with increasing bite angle and reach a maximum value with DPEphos (βn = 102.7° ). Larger bite angles of the diphosphane ligands result in a decreased selectivity and activity.
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  • 96
    ISSN: 1434-1948
    Schlagwort(e): Ligand field spectra ; Phosphonate complexes ; X-ray structures ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis and characterization of transition-metal coordination compounds containing the ligand diethyl 2-quinolylmethylphosphonate (2-qmpe) is described. Complexes of CoII, MnII, NiII, CdII, and ZnII were found to be mutually isomorphous according to their X-ray powder diffraction patterns and IR spectra. The new coordination compounds were identified and characterized by elemental analysis, magnetic measurements, infrared and ligand-field spectra. The crystal structures of the complexes [M(2-qmpe)4(H2O)2](ClO4)2 (M = Ni, 1; Mn, 2) reveal six-coordinate [M(2-qmpe)4(H2O)2] cations with the qmpe ligand coordinating via the oxygen rather than via the nitrogen atom, as well as lattice perchlorate anions. The metal ion is octahedrally surrounded by the four oxygen atoms of the four organic ligands. The non-participation of the pyridine nitrogen atom is unusual. The two water molecules occupy the fifth and the sixth coordination sites in a trans configuration. The coordinated water molecules are strongly hydrogen-bonded to the pyridine nitrogen atom of the 2-qmpe, further stabilizing the solid-state structure. The geometry of the metal ion can be described as distorted octahedral. For the CuII complex, a hydroxo-bridged dinuclear structure of the type [Cu(2-qmpe)2(OH)(H2O)2]2(ClO4)2 is proposed, based on its spectroscopic and magnetic properties. Ligand-field spectra of the Co and Ni compounds were found to be in agreement with the tetragonally distorted octahedral geometry.
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  • 97
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 191-202 
    ISSN: 1434-1948
    Schlagwort(e): Polynuclear complexes ; Carbene complexes ; Bridging ligands ; Alkynyl complexes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The sequential reaction of two equivalents of the dimethylamino(ethynyl)carbene complexes [(CO)5M=C(NMe2)C≡CH] [M = W (1a), Cr (1b)] with two equivalents of nBuLi and one equivalent of a transition metal dichloride, [Cl2M′(Ln)], affords trinuclear biscarbene complexes of the type [(CO)5M=C(NMe2)C≡C-M′(Ln)-C≡CC(NMe)2=M(CO)5] [M′(Ln) = Ni(PEt3)2 (2a, b), Pd(PEt3)2 (3a, b), Pt(PEt3)2 (4a, b), Fe(dmpe)2 (6a), Hg (8a), Ti(η5-C5H5)2 (9a, b)] [dmpe = 1,2-bis(dimethylphosphino)ethane]. Treatment of 1a with equimolar amounts of first nBuLi and then [Cl2M′(Ln)] results in the formation of the monosubstitution products [(CO)5W=C(NMe2)C≡CM′(Ln)] [M′(Ln) = trans-Pd(PEt3)2Cl (5a), trans-Fe(dmpe)2Cl (7a)]. Additionally, the synthesis of the heterobimetallicethynylcarbene complex [(CO)5W=C(NMe2)C≡CPd(PEt3)2C≡CH] (10a), starting from 1a and [ClPd(PEt3)2C≡CH], is described. When three equivalents of 1a are treated, first with three equivalents of nBuLi and then with one equivalent of the trihalides PCl3 or BBr3, the novel tris(ethynylcarbene) complexes [{(CO)5W=C(NMe2)C≡C}3E] [E = B (11a), P (12a)] are obtained. The reaction of four equivalents of 1a,b with four equivalents of nBuLi, followed by addition of one equivalent of a group 14 tetrachloride [M′Cl4], yields the novel tetrakis(ethynylcarbene) complexes [{(CO)5M=C(NMe2)C≡C}4M′] [M′ = Si (13a, b), Ge (14a), Sn (15a, b)]. The complexes 8a, 9a, 12a, and 15a were characterized by X-ray structural analyses. All spectroscopic and structural data suggest that the carbene fragments and the central transition metal or heteroatom in these new bis-, tris-, and tetrakis(ethynylcarbene) complexes interact only weakly.
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  • 98
    ISSN: 1434-1948
    Schlagwort(e): Rhenium ; Oxacyclocarbene complexes ; Vinylidene comlexes ; Alkynols ; Tripodal ligands ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Various β-, γ-, and δ-alkynols have been reacted with the 16e- fragment [(triphos)Re(CO)2]+ generated in situ by H2 elimination from [(triphos)Re(CO)2(η2-H2)]BF4 [triphos = MeC(CH2PPh2)3]. Irrespective of the length of the alkyl chain between the C≡C and OH functional groups in the ω-alkynol, 2-oxacyclocarbene complexes are obtained. These include the 2-oxacyclopentylidene derivatives [(triphos)Re(CO)2{=CCH2CH2CH2O}]BF4 and [(triphos)Re(CO)2{=CCH2CH2CH(Me)O}]BF4, the 2-oxacyclohexylidene dervivatives [(triphos)Re(CO)2{=CCH2CH2CH2CH2O}]BF4 and[(triphos)Re(CO)2{=CCH2CH2CH2CH(Me)O}]BF4, and the 2-oxacycloheptylidene complex [(triphos)Re(CO)2{=CCH2CH2- CH2CH2CH2O}]BF4. The latter compound contains a unprecedented seven-membered oxacarbene ring. The rhenium-assisted δ-alkynol to 2-oxacyloheptylidene rearrangement proceeds via the hydroxybutylvinylidene kinetic intermediate [(triphos)Re(CO)2{C=C(H)CH2CH2CH2CH2OH}]BF4, which has been characterized in both the solid state and solution. An X-ray analysis has been carried out on a single crystal of [(triphos)Re(CO)2{=CCH2CH2CH(Me)O}]BF4. The structure of this complex consists of [(triphos)Re(CO)2{=CCH2CH2CH(Me)O}]+ cations and tetrafluoroborate anions with no interspersed solvent molecules. A facial triphos ligand, two cis-disposed carbonyl groups and a 2-oxacyclopentylidene ligand coordinate the Re centre in a slightly distorted octahedral environment.
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  • 99
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 237-244 
    ISSN: 1434-1948
    Schlagwort(e): Titanium complexes ; Amido-cyclopentadienyl ligand ; Titanium alkyl ; Intramolecular coordination ; Ethene polymerization ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Titanium complexes containing a linked isopropyl- or benzylamido(tetramethylcyclopentadienyl) ligand C5Me4SiMe2NR (R = iPr, CH2Ph,) and one bidentate organyl group C6H4(CH2NMe2)-2, CH2C6H4(NMe2)-2, and {η5-C5H3(CH2NMe2)-2}Fe(η5-C5H5) were prepared by salt metathesis of the corresponding dichloro complex Ti(η5:η1-C5Me4SiMe2NR)Cl2 with the lithium organyl. Single crystal X-ray structural analysis of Ti(η5:η1-C5Me4SiMe2NCH2Ph)- {C6H4(CH2NMe2)-2}Cl and of Ti(η5:η1-C5Me4SiMe2NiPr){CH2C6H4(NMe2)-2}Cl revealed the presence of intramolecular coordination with square pyramidal geometry around titanium. In the ferrocenyl derivative Ti(η5:η1-C5Me4SiMe2NCH2Ph)[{η5-C5H3(CH2NMe2)-2}Fe(η5-C5H5)]Cl the NMe2 group is not bonded at the titanium atom. Ethene polymerization catalyzed by these complexes upon activation with methylaluminoxane was examined.
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  • 100
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1998 (1998), S. 271-274 
    ISSN: 1434-1948
    Schlagwort(e): Zinc complexes ; Pyrazolylborate ligands ; Hydrolytic cleavage ; Diphosphate ; Sulfonatophosphate ; Disulfonate ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Three (pyrazolylborate)zinc hydroxide complexes Tp*Zn-OH were used as hydrolytic reagents to cleave the P-O-P, P-O-S, and S-O-S linkages of organic diphosphates, sulfonatophosphates, and disulfonates. The resulting complexes of the types Tp*Zn-OPO(OR)2 and Tp*Zn-OSO2R could also be obtained by condensation reactions between Tp*Zn-OH and HO-PO(OR)2 or HO-SO2R. Two of them were characterized by structure determinations.
    Materialart: Digitale Medien
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