Tyrosine phosphorylation in platelets Potential roles in intracellular signal transduction

Tyrosine phosphorylation has been shown to play a critical role in the induction of cellular responses to extracellular stimuli in a wide variety of cell types. In platelets, many diverse agonists induce multiple waves of tyrosine phosphorylation, suggesting a potential role for these protein modifications throughout the platelet activation process. Tyrosine phosphorylation of several platelet proteins is regulated by fibrinogen binding to its integrin receptor and subsequent platelet aggregation, suggesting specific functions for tyrosine phosphorylation in integrin-regulated intracellular processes. In this article, we review the regulation of tyrosine phosphorylation and the role of tyrosine phosphorylation in platelet activation events.