Glycoprotein VI is the collagen receptor in platelets which underlies tyrosine phosphorylation of the Fc receptor gamma-chain.
We have recently shown that collagen activates platelets through a pathway dependent on the Fc receptor gamma-chain and the tyrosine kinase Syk. We report here that the Fc receptor gamma-chain and the candidate collagen receptor glycoprotein VI (GPVI) co-associate. Furthermore, cross-linking GPVI stimulates a similar pattern of tyrosine phosphorylation to that stimulated by collagen, including tyrosine phosphorylation of Fc receptor gamma-chain. These results support a model where GPVI couples collagen-stimulation of platelets to phosphorylation of the Fc receptor gamma-chain leading to activation of Syk and phospholipase Cgamma2.
Gibbins
J M
JM
Department of Pharmacology, University of Oxford, UK. jonathan.gibbins@pharmacology.ox.ac.uk
Okuma
M
M
Farndale
R
R
Barnes
M
M
Watson
S P
SP
D001792:Blood Platelets / Q000378:metabolism; D003094:Collagen / Q000494:pharmacology; D003432:Cross-Linking Reagents; D006801:Humans; D007140:Immunoglobulin Fab Fragments; D016023:Integrins / Q000378:metabolism*; D010766:Phosphorylation; D015539:Platelet Activation / Q000502:physiology*; D010980:Platelet Membrane Glycoproteins / Q000378:metabolism*; D038981:Receptors, Collagen; D017452:Receptors, IgG / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
D003432:Cross-Linking Reagents; D007140:Immunoglobulin Fab Fragments; D016023:Integrins; D010980:Platelet Membrane Glycoproteins; D038981:Receptors, Collagen; D017452:Receptors, IgG; D014443:Tyrosine; D003094:Collagen