Influence of CD32 cross-linking on Btk and Tec phosphorylation modulated by PI 3-kinase.

Platelets were incubated with 0.1% DMSO (vehicle for LY294002) or 50 μmol/L LY294002 for 10 minutes. We added 3 μg/mL anti-CD32 for 10 minutes, followed by 30 μg/mL (Fab′)2 of goat antimouse IgG for 5 minutes as indicated. (A) Btk or (B) Tec was purified from the soluble extracts by immunoprecipitation as described above, then immunoblotted with 4G10 antibody (top panels) and anti-Btk or anti-Tec antibody (bottom panels).