Quantitation of GTP-cdc42 from high-speed supernatant prepared from resting platelets or platelets stimulated with 25 μmol/L TRAP or 1 U/mL thrombin.

(A) Measurement of GTP-cdc42 in high-speed platelet supernatant. The plot is an average of 4 experiments (mean ± SD). (inset) Representative anti-cdc42 immunoblot from resting or TRAP-activated cells (30 to 300 seconds). The graph shows that there is a 6-fold increase in the relative amount of GTP-cdc42 collected 30 seconds after TRAP activation. (inset) Representative immunoblot of cdc42 collected with the bead complexes. (B) Graph showing GTP-cdc42 after thrombin (1 U/mL) stimulation of platelets (n = 3, mean ± SD). (inset) Representative experiment of cdc42 bound to the beads in high-speed supernatant from resting or thrombin/TRAP activated cells.