Platelet adhesion to collagen via the alpha 2 beta 1 integrin under arterial flow conditions causes rapid tyrosine phosphorylation of pp125FAK.
Adhesion of human platelets to collagen under arterial flow conditions mediated by the alpha 2 beta 1 integrin increased tyrosine phosphorylation of several proteins, one of which was the focal adhesion tyrosine kinase, pp125FAK. Tyrosine phosphorylation of pp125FAK did not occur in non-adherent flowing platelets or in platelets attached to poly(L-lysine). Neither adhesion nor tyrosine phosphorylation was affected by pretreatment of platelets with GRGDSP peptide or by anti-alpha IIb beta 3 monoclonal antibody P2. Adherent platelets retained their discoid shape, suggesting that induction of pp125FAK precedes platelet spreading. The tyrosine kinase inhibitor erbstatin decreased tyrosine phosphorylation in non-stimulated platelets and blocked platelet adhesion. These results suggest that pp125FAK plays an important role in platelet adhesion to collagen via the alpha 2 beta 1 integrin.
Polanowska-Grabowska
R
R
Department of Biochemistry, University of Virginia Health Science Centre, Charlottesville 22908.
Geanacopoulos
M
M
Gear
A R
AR
D000595:Amino Acid Sequence; D001158:Arteries / Q000502:physiology*; D001775:Blood Circulation; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism* / Q000648:ultrastructure; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D006801:Humans; D016023:Integrins / Q000378:metabolism*; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011972:Receptor, Insulin / Q000037:antagonists & inhibitors / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*
D015815:Cell Adhesion Molecules; D016023:Integrins; D014443:Tyrosine; D003094:Collagen; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human