Lenticular intermediate-sized filaments: biosynthesis and interaction with plasma membrane.
Electron microscopical features of the lens fiber plasma membrane-cytoskeleton complex are suggestive of an intimate association between the intermediate-sized filaments (IF) and the lipid bilayer. Biochemical analysis of this complex reveals the occurrence of an appreciable amount of vimentin as a protein subunit of lenticular IF. Additional evidence for association between IF and membranes is provided by the observation that newly synthesized vimentin is associated with plasma membranes added to a reticulocyte lysate programmed with lens polyribosomes. Concomitantly alpha-crystallin polypeptide chains (alpha A2) are also found associated with the plasma membrane together with a hitherto unidentified 47-kilodalton protein. Once associated with the lipid bilayer, the vimentin polypeptide resists urea treatment, suggesting that it has become an integral constituent associated with part of the membrane.
D000818:Animals; D002417:Cattle; D002458:Cell Fractionation / Q000379:methods; D002462:Cell Membrane / Q000648:ultrastructure*; D003459:Crystallins / Q000378:metabolism; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D007908:Lens, Crystalline / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008970:Molecular Weight; D009124:Muscle Proteins / Q000378:metabolism; D014746:Vimentin
D003459:Crystallins; D009124:Muscle Proteins; D014746:Vimentin