Proximal signaling mechanisms are not impaired in VAMP-7−/− platelets. (A) [Ca2+]i flux in wild-type and VAMP-7−/− mice incubated with fura-2 was monitored after incubation with the indicated concentrations of AYPGKF. (B) Immunoblot analysis using an anti-phosphoserine/phosphothreonine antibody (PS/PT; left) or an anti-phosphotyrosine antibody (PY) of lysates (right) from wild-type and VAMP-7−/− (V7−/−) platelets before (Resting) and after (Activated) stimulation with 150 μM AYPGKF. (C) Wild-type (top) and VAMP-7−/− platelets (bottom) were stained with anti-CD41 antibody and evaluated by flow cytometry. (D) Wild-type (top) and VAMP-7−/− platelets (bottom) were incubated in the presence of vehicle (Resting; left) or 150 μM AYPGKF (Activated; right), stained with Jon/A antibody, and evaluated by flow cytometry.