Restoration of microfilament bundle organization in v-raf-transformed NRK cells after transduction with tropomyosin 2 cDNA

1994 ◽  
Vol 87 (1) ◽  
pp. 47-53 ◽  
Author(s):  
Keizo Takenaga ◽  
Akira Masuda
Keyword(s):  
Microfilament Bundle

Development of macrociliary cells in Beroe. I. Actin bundles and centriole migration

1988 ◽  
Vol 89 (1) ◽  
pp. 67-80
Author(s):  
S. Tamm ◽  
S.L. Tamm
Keyword(s):  
Cell Membrane ◽  
Basal Body ◽  
Actin Filaments ◽  
Close Association ◽  
Directed Assembly ◽  
Double Layers ◽  
Basal Bodies ◽  
Apical Surface ◽  
Actin Bundle ◽  
Microfilament Bundle

Differentiation of macrociliary cells on regenerating lips of the ctenophore Beroe was studied by transmission electron microscopy. In this study of early development, we found that basal bodies for macrocilia arise by an acentriolar pathway near the nucleus and Golgi apparatus, in close association with plaques of dense fibrogranular bodies. Procentrioles are often aligned side-by-side in double layers with the cartwheel ends facing outward toward the surrounding plaques of dense granules. Newly formed basal bodies then disband from groups and develop a long striated rootlet at one end. At the same time, an array of microfilaments arises in the basal cytoplasm. The microfilaments are arranged in parallel strands oriented toward the cell surface. The basal body-rootlet units are transported to the apical surface in close association with the assembling actin filament bundle. Microfilaments run parallel to and alongside the striated rootlets, to which they often appear attached. Basal body-rootlet units migrate at the heads of trails of microfilaments, as if they are pushed upwards by elongation of their attached actin filaments. Near the apical surface the actin bundle curves and runs below the cell membrane. Newly arrived basal body-rootlets tilt upwards out of the microfilament bundle to contact the cell membrane and initiate ciliogenesis. The basal bodies tilt parallel to the flat sides of the rootlets, and away from the direction in which the basal feet point. The actin bundle continues to enlarge during ciliogenesis. These results suggest that basal body migration may be driven by the directed assembly of attached actin filaments.

Microfilament-Supported Macrovilli in the Hindgut of the Polychaete Dinophilusgyrociliatus

1986 ◽  
Vol 41 (11-12) ◽  
pp. 1139-1144 ◽  
Author(s):  
Ulrich Oster
Keyword(s):  
Cytochalasin B ◽  
Maximal Length ◽  
Cell Type ◽  
Microfilament Bundle ◽  
Dinophilus Gyrociliatus

Abstract Large macrovilli of 7.7 μm maximal length and a diameter of 0.4 μm with several hundred cytochalasin B-sensitive 6 nm microfilaments are found as bordering lateral struc­tures in the ciliary groove of the hindgut of Dinophilus gyrociliatus. The microfilament bundle, accompanied by microtubules, extends with its tapering rootlets to the base of the cells. Another cell type in the middle of the groove bears the cilia and equally broad, but shorter macrovilli with a cytochalasin-sensitive microfilament core.

scholarly journals Distribution of the cell substratum attachment (CSAT) antigen on myogenic and fibroblastic cells in culture.

1985 ◽  
Vol 100 (5) ◽  
pp. 1528-1539 ◽  
Author(s):  
C H Damsky ◽  
K A Knudsen ◽  
D Bradley ◽  
C A Buck ◽  
A F Horwitz
Keyword(s):  
Cell Adhesion ◽  
Surface Membrane ◽  
Membrane Glycoproteins ◽  
Myogenic Cells ◽  
Microfilament Bundle ◽  
Cell Matrix ◽  
Cell Biol ◽  
The Stability ◽  
Adhesive Contacts ◽  
Fibroblastic Cells

Previous studies (Neff et al., 1982, J. Cell. Biol. 95:654-666; Decker et al., 1984. J. Cell. Biol. 99:1388-1404) have described a monoclonal antibody (CSAT Mab) directed against a complex of three integral membrane glycoproteins of 120,000-160,000 mol wt (CSAT antigen [ag]) involved in the cell matrix adhesion of myoblasts and fibroblasts. In localization studies on fibroblasts presented here, CSAT ag has a discrete, well-organized distribution pattern. It co-aligns with portions of stress fibers and is enriched at the periphery of, but not directly beneath vinculin-rich focal contacts. In this last location, it co-distributes with fibronectin, consistent with the suggestion that the CSAT ag participates in the mechanism by which fibroblasts attach to fibronectin. In prefusion myoblasts, which are rapidly detached by CSAT Mab, CSAT ag is distributed diffusely as are vinculin, laminin, and fibronectin. After fusion, myotubes become more difficult to detach with CSAT Mab. The CSAT ag and vinculin are organized in a much more discrete pattern on the myotube surface, becoming enriched at microfilament bundle termini and in lateral lamellae which appear to attach myotubes to the substratum. These results suggest that the organization of CSAT ag-adhesive complexes on the surface of myogenic cells can affect the stability of their adhesive contacts. We conclude from the sum of the studies presented that, in both myogenic and fibroblastic cells, the CSAT ag is localized in sites expected of a surface membrane mediator of cell adhesion to extracelluon of CSAT ag-adhesive complexes on the surface of myogenic cells can affect the stability of their adhesive contacts. We conclude from the sum of the studies presented that, in both myogenic and fibroblastic cells, the CSAT ag is localized in sites expected of a surface membrane mediator of cell adhesion to extracellular matrix. The results from studies that use fibroblasts in particular suggest the involvement of CSAT ag in the adhesion of these cells to fibronectin.

Features of Formation of a Multifilament Yarn from Crystallizing and Amorphic High-Heat Resistant Thermoplastics

2020 ◽  
Vol 869 ◽  
pp. 524-531
Author(s):  
Ismel V. Musov ◽  
Azamat L. Slonov ◽  
Azamat Zhansitov ◽  
Zhanna I. Kurdanova ◽  
Svetlana Yu. Khashirova
Keyword(s):  
High Performance ◽  
Cold Drawing ◽  
High Heat ◽  
Polyphenylene Sulfide ◽  
Post Processing ◽  
Molding Process ◽  
Laboratory Conditions ◽  
Heat Resistant ◽  
Microfilament Bundle ◽  
Multifilament Yarn

In laboratory conditions, the molding process was simulated by extrusion of a multifilament yarn with a diameter of the monofilament equal 250-350 μm from high performance plastics. The possibility of obtaining a microfilament bundle of polyetheretherketone, polyphenylene sulfide and polyetherimide using a specially made forming head is shown. The technological modes of extrusion have been worked out, which makes it possible to obtain thermoplastic fibers from the studied thermoplastics. It was revealed that the obtained microfilaments can be subjected to post-processing by cold drawing to reduce their diameter by 40-70 %.

Role of microvillar cell surfaces in the regulation of glucose uptake and organization of energy metabolism

2002 ◽  
Vol 282 (1) ◽  
pp. C1-C26 ◽  
Author(s):  
Klaus Lange
Keyword(s):  
Glucose Metabolism ◽  
Glucose Uptake ◽  
Metabolic Regulation ◽  
General Concept ◽  
Characteristic Functions ◽  
Resting Cells ◽  
Cell Surfaces ◽  
Differentiated Cells ◽  
Microfilament Bundle ◽  
Metabolic Substrates

Experimental evidence suggesting a type of glucose uptake regulation prevailing in resting and differentiated cells was surveyed. This type of regulation is characterized by transport-limited glucose metabolism and depends on segregation of glucose transporters on microvilli of differentiated or resting cells. Earlier studies on glucose transport regulation and a recently presented general concept of influx regulation for ions and metabolic substrates via microvillar structures provide the basic framework for this theory. According to this concept, glucose uptake via transporters on microvilli is regulated by changes in the structural organization of the microfilament bundle, which is acting as a diffusion barrier between the microvillar tip compartment and the cytoplasm. Both microvilli formation and the switch of glucose metabolism from “metabolic regulation” to “transport limitation” occur during differentiation. The formation of microvillar cell surfaces creates the essential preconditions to establish the characteristic functions of specialized tissue cells including the coordination between glycolysis and oxidative phosphorylation, regulation of cellular functions by external signals, and Ca2+ signaling. The proposed concept integrates various aspects of glucose uptake regulation into a ubiquitous cellular mechanism involved in regulation of transmembrane ion and substrate fluxes.

Modulation by retinyl acetate of microfilament bundle formation in C3H/10T1/2 cells

1984 ◽  
Vol 24 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Lawrence J. Mordan ◽  
Sek-Wen Hui ◽  
John S. Bertram
Keyword(s):  
Retinyl Acetate ◽  
Microfilament Bundle

Microfilaments in plant vascular cells

1980 ◽  
Vol 58 (7) ◽  
pp. 807-815 ◽  
Author(s):  
M. V. Parthasarathy ◽  
T. C. Pesacreta
Keyword(s):  
Actin Filaments ◽  
Vascular Tissue ◽  
Longitudinal Axis ◽  
Vascular Cells ◽  
Microfilament Bundle ◽  
Microfilament Bundles ◽  
Size And Morphology ◽  
Oriented Parallel ◽  
Peripheral Regions

Microfilaments 50–70 Å (Å = 0.1 nm) in diameter are commonly found in vascular tissue of elongating roots and stems of many plants. Such microfilaments occur in bundles in peripheral regions of elongating or differentiating vascular cells, and are usually oriented parallel to the longitudinal axis of the cells. Although the longest microfilament bundle we have measured is about 15 μm, we suspect that the bundles are at least as long as the cells that contain them. The bundles are 0.1–0.4 μm in width and are often in apparent contact with organelles, but there is no definite indication of their being anchored to plasmalemma or any organelle. The microfilaments are comparable in size and morphology to actin filaments. The distribution of microfilament bundles in the vascular tissue of various plants and the possible function of the bundles is discussed.

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