Kinetics of phosphorylation after FcγRIIA-dependent activation. Washed platelets from carriers (n = 3, ▨) and noncarriers of the CD148 276P/326Q alleles (n = 3, ▩) were activated by 2.5 μg/mL ALB6 in the absence of aggregation (tirofoban) and then lysed at 0, 90, 120, or 150 seconds. Platelet lysates were western blotted with an anti–phospho-tyrosine and antiactin (A), or antibodies against LAT p-Tyr 191, PLCγ2 p-Tyr 753, and PLCγ2 (Bi-ii), an anti-Src p-Tyr 146 (C), or an anti-Lyn p-Tyr-507 (D). In panels Bii, C, and D, band intensities were quantified (mean ± SEM; *P < .05 and ** P < .01, t test).