Association of actin with the platelet membrane.
Human platelet membrane-actin associations were studied by means of differential extraction of purified membranes and low-shear viscometry of membrane-F-actin mixtures. As indicated by resistance to extraction with 0.6 M potassium iodide, a significant amount of platelet actin appears to be tightly associated with the membrane. When tested by falling-ball viscometry, both whole and KI-extracted membranes increased the low-shear viscosity of preformed rabbit skeletal muscle F-actin at physiologically reasonable pH and ionic conditions. This membrane-associated actin gelation activity was dependent upon low free calcium concentration (10(-8)-10(-7) M). The results are consistent with specific associations between actin and platelet membranes and may be relevant to membrane-cytoskeletal interactions believed to occur in the intact cell.
D000199:Actins / Q000097:blood*; D001792:Blood Platelets / Q000648:ultrastructure*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000648:ultrastructure; D002499:Centrifugation, Density Gradient / Q000379:methods; D003902:Detergents; D006801:Humans; D008565:Membrane Proteins / Q000097:blood / Q000302:isolation & purification; D008970:Molecular Weight; D017830:Octoxynol; D011092:Polyethylene Glycols; D014783:Viscosity
D000199:Actins; D003902:Detergents; D008565:Membrane Proteins; D011092:Polyethylene Glycols; D017830:Octoxynol