ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 1-1 
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 81-101 
    ISSN: 0886-1544
    Keywords: fast axonal transport ; isolated axoplasm ; video microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The development of AVEC-DIC microscopy and the application of this method to the study of fast axonal transport in isolated axoplasm extruded from the giant axon of the squid Loligo pealei provides a new paradigm for analyzing the intracellular transport of membranous organelles. The size of the axon, the number of transported particles, and the absence of permeability barriers like the plasma membrane in this preparation permit many experiments that are difficult or impossible to perform using other model systems. The use and features of this preparation are described in detail and a number of properties are evaluated for the first time. The process of extrusion is characterized. Particle movement is evaluated both in the interior of extruded axoplasm and along individual fibrils that extend from the periphery of perfused axoplasm. The role of divalent cations, particularly Ca2+, and the effects of elevated Ca2+ on axoplasmic organization and transport are analyzed. A series of pharmacological agents and polypeptides that alter cytoskeletal organization are used to examine the role of microfilaments and microtubules in fast transport. Finally, the effects of depleting ATP and of adding ATP analogues are discussed. The extruded axoplasm preparation is shown to be an invaluable model system for biochemical and pharmacological analyses of the molecular mechanisms of intracellular transport.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We present a high-resolution electron microscopic study of the sidearms on microtubules and vesicles that are suggested to form the crossbridges which produce the microtubule-based vesicle transport in squid axoplasm. The sidearms were found attached to the surfaces of the anterogradely transported vesicles in the presence of ATP. These sidearms were made of one to three filaments of uniform diameter. Each filament measured 5-6 nm in width and 30-35 nm in length. The filaments in some of the sidearms had splayed apart by pivoting at their base, thereby assuming a “V” shape. The spread configuration illustrated the independence of the individual filaments. The filaments in other sidearms were closely spaced and oriented parallel to each other, a pattern called the compact configuration. In axoplasmic buffer containing AMP-PNP, structures indistinguishable from the filaments of the sidearms on the vesicles were observed attached to microtubules. Pairs of filaments, thought to represent the basic functional unit, were observed attached to adjacent protofilaments of the microtubules by their distal tips. These data support a model of vesicle movement in which a pair of filaments within a sidearm forms two crossbridges and moves a vesicle by “walking” along the protofilaments of the microtubule.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. 31-51 
    ISSN: 0886-1544
    Keywords: microtubules ; birefringence ; flow birefringence ; tubulin ; polarization microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Understanding the molecular basis of mitotic movements in living cells will require correlative experiments on intact cells, cell models, purified tubulin, and perhaps other biopolymers. Birefringence is one assay that is useful in all of these experimental situations. Heretofore, studies of birefringence changes during mitosis have lacked a quantitiative basis for interpretation in terms of microtubule number and packing density. One of the aims of this work was to establish that relationship.Purified calf brain tubulin was polymerized to equilibrium and oriented in the hydrodynamic field of a microcapillary flow birefringence apparatus. The relationship between birefringence and microtubule packing density was determined by a combination of optical, electron microscopic, and biochemical methods. The data correlate surprisingly well with those obtained by others from in vitro measurements on isolated mitotic spindles. Using the flow birefringence data, the sensitivity of polarizing microscopes for detecting microtubules was examined and found to depend on microtubule packing density, object thickness, and instrumental factors that limit both the detection and measurement of weakly birefringent objects. Because of the dependence of measurement sensitivity on object thickness, a method of measuring the thickness of microtubule bundles using the dispersion of birefringence was developed. This method is capable of measuring thickness to within two or three Airy diffraction units and does not require any assumptions regarding object symmetry.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 5 (1985), S. i 
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 406-418 
    ISSN: 0886-1544
    Keywords: Intermediate filaments ; microfilaments fibroblast cell spreading ; focal center ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Spreading and fully spread chick embryo fibroblasts (CEF) were examined by double-label fluorescence microscopy using the actin-specific probe rhodamine-phalloidin and an antibody directed against CEF intermediate filaments (IF). During midspreading, a striking relationship became discernible: statistical analysis showed that approximately half of the cell population exhibited one or more phase-dense, phalloidin-binding nodules that appeared to act as foci from which IF diverged. Coincidence between actin-containing structures and IF was not limited to these centers; IF could also frequently be seen running in close parallel arrays with stress fibers.Ultrastructural analysis confirmed the presence of non-membrane-bound out-pocketings along the length of stress fibers from which 10-nm IF diverged. These structures varied in size and shape, and displayed a dense, fine fibrillar appearance. IF and microfilaments (MF) were distinguished by size and by decoration of MF with myosin subfragment-1. Other IF-MF interactions were seen in cells of all stages: IF were observed to loop through stress fibers, most frequently at the cell margins. In colchicine-treated cells, IF became redistributed into cables that often ran parallel and appeared to merge with stress fibers. Cytochalasin D-treated CEF exhibited loose aggregates of actin-containing material that appeared to be associated with IF.These results suggest the possibility of an interaction between actin-containing structures and IF, particularly during cell spreading in cultured fibroblasts.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 389-405 
    ISSN: 0886-1544
    Keywords: cell membrane complex ; extracellular matrix ; fibronectin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Intermediate filaments (IF) were found in close proximity to the plasma membrane in substrate attached baby hamster kidney cells (BHK-21) and chick embryo fibroblasts (CEF) as well as cells removed from their substrate in the absence of trypsin. However, in cells removed with trypsin, it appeared that IF had retracted away from the membrane. In cells with abundant extracellular matrix (ECM), colchicine induced massive cables of IF, which appeared to interact with specialized areas of the inner plasma membrane. In cells lysed to extract most microfilaments and cytoplasmic constituents, the intact IF network which remained was closely associated with the ECM. From these ultrastructural observations it was concluded that IF interact in some way with a “cell membrane complex” defined as comprising the plasma membrane and molecules attached to its inner and outer surfaces.In order to investigate the possibility that components of the membrane complex may co-isolate with IF, native intermediate filaments (NIF) were prepared. In addition to the structural subunits and other associated polypeptides, a ∼220 kd species which reacted specifically with antibodies directed against the ECM protein fibronectin (FN) was observed; 220 kd was still present after NIF were isolated under pH conditions where FN is more soluble, suggesting that its presence was not simply due to the coprecipitation of two insoluble proteins. Immunofluorescence and immunogold localization confirmed that FN is a component of the cell membrane complex with which IF appeared to interact.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 8 (1987), S. 284-291 
    ISSN: 0886-1544
    Keywords: tyrosination ; acetylation ; post-translational modifications ; cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have examined the distribution of acetylated α-tubulin using immunofluorescence microscopy in fibroblastic cells of rat brain meaninges. Meningeal fibroblasts showed heterogenous staining patterns with a monoclonal antibody against acetylated α-tubulin ranging from staining of primary cilia or microtubule-organising centers (MTOCs) alone to extensive microtubule networks. Staining with a broad spectrum anti-α-tubulin monoclonal indicated that all cells possessed cytoplasmic microtubule networks. From double-labeling experiments using an antibody against acetylated α-tubulin (6-11B-1) and antibodies against either tyrosinated or detyrosinated α-tubulin, it was found that acetylated α-tubulin and tyrosinated α-tubulin were often segregated to different microtubules. The microtubules containing acetylated but not tyrosinated α-tubulin were cold stable. Therefore, it appeared that in general meningeal cells possessed two subset of microtubules: One subset contained detyrosinated and acetylated α-tubulin and was cold stable, and the other contained tyrosinated α-tubulin and was cold labile. These results are consistent with the idea that acetylation and detyrosination of α-tubulin are involved in the specification of stable microtubules.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 10 (1988), S. 438-449 
    ISSN: 0886-1544
    Keywords: tyrosinated microtubules ; organelle distribution/transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have recently shown that acetylated α-tubulin containing microtubules (acety1-MTs; labeled by antibody 6-11B-1) constitute a cold-stable subset of the microtubule network of nonneuronal cells in rat primary forebrain cultures [Cambray-Deakin and Burgoyne: Cell Motil. 8(3):284-291, 1987b]. In contrast, tyrosinated α-tubulin containing MTs (tyr-MTs; labeled by antibody YL1/2) are cold-labile. Here we have examined the distribution of acety1-MTs and tyr-MTs in cultures of newborn rat forebrain astrocytes and simultaneously investigated the distribution of mitochondria and glial filaments. In double-label immunofluorescence experiments a marked colocalisation of acetyl-MTs and glial filament bundles was observed. Tyr-MTs did not show a similar colocalisation with glial filament bundles. Furthermore, the distribution of mitochondria closely followed that of the acetyl-MT and glial filament bundles. When cells were exposed to short-term (30-min) treatments with MT-disrupting agents such as colchicine and nocodazole, the tyr-MT network was removed but the distributions of acetyl-MTs, glial filaments, and mitochondria were unchanged. Increased exposure to colchicine (9-16 hr) caused a progressive disruption of the acetyl-MTs and the collapse of glial filaments and mitochondria to the perinuclear region. These results suggest that acetyl-MTs and glial filaments but not tyr-MTs may be involved in the intracellular transport of organelles and/or in the control of their cytoplasmic distribution.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 12 (1989), S. 273-282 
    ISSN: 0886-1544
    Keywords: cytoskeleton ; microtubules ; axons ; sensory neurons ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The comparative distribution of tyrosinated, detyrosinated, and acetylated α-tubulins was examined in neurites of rat dorsal root ganglion neurones in culture using immunofluorescence microscopy. Phase contrast observations of single neurones revealed that the neurites were actively motile, and rhodamine phalloidin staining of actin filaments showed the extent of lamellopodia and microspike projections from the growth cones. From double-labelling experiments using antibodies against tyrosinated, detryrosinated, or acetylated α-tubulin, it was found that the three different isoforms were differentially localised in neurites and growth cones. Detyrosinated and acetylated forms of α-tubulin were in the main restricted to the neurites extending no further than the base of the growth cones. Tyrosinated α-tubulin was, however, distributed throughout the body of the growth cone and into the base of some microspikes. Following treatment with taxol to promote microtubule assembly, detyrosinated and acetylated α-tubulins were found to be colocalised with tyrosinated α-tubulins throughout the growth cones of all cells examined. These results would be consistent with axonal transport of tyrosinated α-tubulin followed by assembly in the growth cone and subsequent detyrosination and acetylation. In addition the presence of unmodified α-tubulin in the growth cone may be necessary for the provision of labile microtubules for growth cone motility and extension.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...