OxLDL-induced Vav1 phosphorylation is mediated by src kinase Fyn. (A) Human platelets were incubated with the broad-spectrum src inhibitor AG1879 before incubation with 50 μg/mL oxLDL. The platelet lysates were then analyzed as in Figure 1 for Vav1 phosphorylation. (B) Platelets were incubated without or with oxLDL and then lysed. Vav1 was precipitated by an Ab specific for Vav1. Precipitates were analyzed by immunoblot with 4G10 anti-phosphotyrosine Ab, Vav1 Ab, and Fyn Ab (mouse). (C) Platelets were incubated without or with oxLDL and then lysed. Fyn was precipitated with an anti-Fyn Ab (mouse). Precipitates were analyzed by immunoblot with Vav1 Ab and Fyn Ab (Rabbit).