ALBERT — All Library Books, journals and Electronic Records Telegrafenberg

Treffer pro Seite

Treffer 1 - 3 | 3 Treffer

Sortierung

Digitale Medien

1H, 15N, 13C and 13CO resonance assignments and secondary structure of villin 14T, a domain conserved among actin-severing proteins (1994)

Markus, Michelle A. ; Nakayama, Tomoko ; Matsudaira, Paul ; [weitere]

Springer

Journal of biomolecular NMR 4 (1994), S. 553-574

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1573-5001

Schlagwort(e): Villin 14T ; Heteronuclear multidimensional NMR ; Chemical shift assignments ; Hydrogen exchange ; Calcium titration ; pH titration

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie , Chemie und Pharmazie

Notizen: Summary Sequence-specific assignments have been made for the 1H, 15N, 13C and 13CO resonances of 14T, the 126-residue amino-terminal domain of the actin-severing protein villin. Villin is a member of a family of proteins that regulate cytoskeletal actin by severing, capping and nucleating actin filaments. Actin binding is dependent on calcium and disrupted by phosphatidyl inositol 4,5-bisphosphate. Actin-severing proteins are built from three or six repeats of a conserved domain, represented by 14T. Expression in Escherichia coli facilitated incorporation of 15N and 13C isotopes and application of triple-resonance, backbone-directed strategies for the sequential assignments. Elements of regular secondary structure have been identified by characteristic patterns of NOE cross peaks and values of vicinal 3JH n Hα coupling constants. Amide protons that exchange slowly (rates less than 1.0×10-4 per min) are concentrated in the central β-sheet and the second and third α-helices, suggesting that these elements of secondary structure form very stable hydrogen bonds. Assignments for the amide nitrogens and protons have been examined as a function of pH and calcium concentration. Based on the conservation of chemical shifts in the core of the domain, villin 14T maintains the same overall fold in the pH range from 4.15 to 6.91 and the calcium range from 0 to 50 mM. The calcium data indicate the presence of two calcium-binding sites and suggest their locations.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00156620

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Fimbrin localized to an insoluble cytoskeletal fraction is constitutively phosphorylated on its headpiece domain in adherent macrophages (1993)

Messier, Jeanne M. ; Shaw, Leslie M. ; Chafel, Mark ; [weitere]

New York, NY : Wiley-Blackwell

Cell Motility and the Cytoskeleton 25 (1993), S. 223-233

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0886-1544

Schlagwort(e): actin-bundling protein ; phosphorylation ; macrophage fractions ; Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Medizin

Notizen: The actin-bundling protein fimbrin is homologous to l-plastin, a 65kD phosphoprotein expressed in leukocytes and transformed cells [de Arruda et al., J. Cell Biol. 111, 1069-1080]. Because fimbrin is present in cell adhesion sites, we studied the phosphorylation state of fimbrin and its distribution in macrophages sequentially extracted with Triton-X-100 (soluble fraction), Tween 40-deoxy-cholate (cytoskeletal fraction), and SDS (insoluble cytoskeletal fraction). The approximate distribution of fimbrin and actin among these fractions was found to be: 65% fimbrin/55% actin in the soluble fraction, 30% fimbrin/20% actin in the cytoskeletal fraction, and 5% fimbrin/25% actin in the insoluble cytoskeletal fraction. PMA did not alter this distribution. Fluorescence microscopy of acetone-extracted macrophages showed that actin is concentrated in podosomes at the substratum interface and is diffusely distributed throughout the remainder of the cell. Fimbrin colocalizes with actin in podosomes and also exhibits a punctate distribution in the cytoplasm that overlaps with actin. In Tween 40/DOC-extracted cells, podosomes remain, and fimbrin also exhibits a punctate distribution along actin filaments. Metabolic 32PO4 labeling revealed that fimbrin is constitutively phosphorylated and that phosphorylated fimbrin is concentrated in the insoluble cytoskeletal fraction. PMA increased the relative levels of fimbrin phosphorylation twofold but did not alter the pattern of fimbrin fluorescence or the distribution of phosphorylated fimbrin. Limited trypsin digestion and phosphoamino acid analysis demonstrated that phosphorylation occurs specifically on serine residues within the 10kD headpiece domain of fimbrin. Phosphorylation of the headpiece domain could regulate the actin binding and bundling properties of fimbrin, or it could regulate the interaction of fimbrin with other proteins. © 1993 Wiley-Liss, Inc.

Zusätzliches Material: 7 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/cm.970250303

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Recombinant expression of the brush border myosin I heavy chain (1995)

Collins, Kathleen ; Matsudaira, Paul T.

New York, NY : Wiley-Blackwell

Cell Motility and the Cytoskeleton 32 (1995), S. 151-161

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0886-1544

Schlagwort(e): membrane localization ; ATPase activity ; actin binding ; calmodulin ; motility ; Life and Medical Sciences ; Cell & Developmental Biology

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Biologie , Medizin

Notizen: Although the specific functions of myosin I motors are not known, their localization to membrane structures suggests a function in membrane motility. Different myosin I isoforms in the same cell or in different cells can possess different localizations. To determine if the localization and biochemical activity of the best-characterized mammalian myosin I, chicken intestinal epithelium brush border myosin I, was dependent on determinants of the membrane or actin cytoskeleton specific to epithelial cells, we transfected the cDNA for the heavy chain of this myosin into COS cells. Transient transfection of COS cells with the chicken brush border myosin I heavy chain resulted in the production of recombinant myosin I. Recombinant brush border myosin I localized to protrusions of the plasma membrane, particularly at spreading cell edges, and also to unknown cytoplasmic structures. Some cells expressing particularly high levels of brush border myosin I possessed a highly irregular surface. Recombinant brush border myosin I purified from COS cells bound to actin filaments in an ATP-dependent manner and decorated actin filaments to form a characteristic appearance. The recombinant myosin also catalyzed calcium-sensitive, actin-activated MgATPase activity similar to that of the native enzyme. Thus, any cellular factor required for the general membrane localization or biochemical activity of brush border myosin I is present in COS cells as well as intestinal epithelium.

Zusätzliches Material: 5 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/cm.970320216

Permalink

	Standort	Signatur	Erwartet	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Treffer 1 - 3 | 3 Treffer