Membranes cytoskeletal anchors

The manner by which shear stress-induced cellular changes occur in endothelial cells involves cell membrane and cytoskeletal molecules that lead to a shape change. The cytoskeleton contains actin filaments, intermediate filaments, and microtubules, all of which are restructured upon exposure to external force. Under stress conditions, actin filaments coalesce to form stress fibers that anchor at the focal contacts, which are adhesion sites at the cell substrate interface. 

Cell salvage may be caused by fusion of the IL lipid bilayer with the cell membrane promoted by the anchoring of the IL plug to the underlying cytoskeletal myofilaments with AM on the IL surface. The mechanism of cell salvage may also be by simple plugging of the sarcolemmal lesions with the IL kept in place by the antibody anchors. Whatever the exact mechanism, this model of intervention provided a novel approach to preservation of cell viability. 

In keeping with their proposed cytoskeletal nature, IFPs initially were thought to serve a purely structural role in muscle cells. It was hypothesized that the function of these proteins was to keep other cytoplasmic proteins in proper relationship to one another, as well as to anchor the cytoplasmic contractile apparatus to the cell membrane. Flowever, subsequent developments in cell biology cast considerable doubt on this premise." The intermediate filaments are now known to serve a nucleic acid-binding function moreover, they are susceptible to processing by calcium-activated proteases and are substrates for cyclic adenosine monophosphate-dependent protein kinases. Thus, it has been proposed that all IFPs serve as modulators between extracellular influences governing calcium flux into the cell (and subsequent protease activation) and nuclear function at a transcriptional... 

PI is involved in membrane anchoring of proteins via GPI and the inositol moiety is a substrate for lipid kinases yielding phosphoinositides involved in cytoskeletal organization, vesicle transport and signal transduction. 

Fig. 6. Organization of structural elements within the smooth muscle cell. For purposes of simplicity, the contractile filaments are illustrated on the left side of the cell, whereas the cytoskeletal filaments are illustrated on the right side. Thin filaments composed of contractile actin (a or y isoforms) are proposed to associate with thick filaments. Thin filaments composed of cytoskeletal actin do not associate with myosin (as reviewed by Small (1995)). Actin filaments anchor at dense bodies in the cytosol and dense plaques at the cell membrane via linker proteins. Intermediate filaments link chains of dense bodies. Intermediate filaments are also linked to the cell surface at dense plaques...

The lymphatic endothelium has a number of similarities with vascular endothelium. It forms a continuous lining and has typical cytoskeletal fibers such as microtubules, intermediate fibers, and actin in both fiber bundle form and mafric form. There are numerous caveolae, Weibel-Palade bodies, but lymphatic endothelium has fewer interendothehal adhesion complexes and a discontinuous basement membrane. The residues of the basement membrane are attached to interstitial collagen via anchoring filaments [Leak and Burke, 1968] that provide relatively hrm attachment of the endothelium to interstitial structures. 

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