Reciprocal transmembranous receptor-cytoskeleton interactions in concanavalin A-activated platelets.
Concanavalin A (Con A) has been used to activate platelets, inducing a specific interaction between the glycoprotein IIb-IIIa complex and the cytoskeleton of the activated platelet. In agreement with this, we have shown that Con A activates human platelets, initiating phosphorylation, secretion, and cytoskeletal formation. Con A and cytochalasin B were used to demonstrate a reciprocal interaction of the glycoprotein complex with the platelet cytoskeleton. Additionally, we have shown that a similar reciprocity is provided by the multivalent fibrin-fibrinogen platelet interaction found in the thrombin-induced clot. Con A differs from other activators in precipitating an apparent cytoskeletal core despite a complete inhibition of platelet activation by prostaglandin E1. We suggest, from this result, that Con A may be cross-linking a membrane-associated cytoskeletal complex present in the unactivated platelet.
Wheeler
M E
ME
Gerrard
J M
JM
Carroll
R C
RC
D000199:Actins / Q000378:metabolism; D000527:Alprostadil; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D002352:Carrier Proteins / Q000378:metabolism; D003208:Concanavalin A / Q000494:pharmacology*; D003599:Cytoskeleton / Q000378:metabolism*; D005340:Fibrinogen / Q000378:metabolism; D018260:Gelsolin; D006023:Glycoproteins / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D008840:Microfilament Proteins; D009218:Myosins / Q000378:metabolism; D010766:Phosphorylation; D010974:Platelet Aggregation; D010980:Platelet Membrane Glycoproteins; D011458:Prostaglandins E / Q000494:pharmacology; D011956:Receptors, Cell Surface / Q000378:metabolism*
D000199:Actins; D002352:Carrier Proteins; D018260:Gelsolin; D006023:Glycoproteins; D008565:Membrane Proteins; D008840:Microfilament Proteins; D010980:Platelet Membrane Glycoproteins; D011458:Prostaglandins E; D011956:Receptors, Cell Surface; C016953:brevin; D003208:Concanavalin A; D005340:Fibrinogen; D009218:Myosins; D000527:Alprostadil