Cross-linking of JAQ1 induces full platelet aggregation and intracellular calcium mobilization.

Washed platelets were incubated with JAQ1 (10 μg/mL) alone or JAQ1 followed by polyclonal antirat IgG antibodies (10 μg/mL). (A) JAQ1 alone does not induce aggregation, whereas cross-linking of surface-bound JAQ1 induces strong aggregation that is insensitive to aspirin treatment (1 mM, 15 minutes, 37°C), apyrase (2 U/mL), or CP/CPK (10 mM/20 U/mL). The trace shown was obtained in the presence of aspirin and apyrase. Traces obtained in the presence of aspirin and CP/CPK were similar. (B) JAQ1 only induces intracellular calcium mobilization on cross-linking.