Reduced IgE/antigen-induced FcR γ-chain tyrosine phosphorylation in PigA-deficient BMMCs. After sensitization of BMMCs with IgE anti-DNP for 3 hours at 37°C, DNP-BSA (Ag) was added and the cells were challenged for 3 minutes at 37°C, or left on ice (0 minutes), and lysed. Top panel: immunoprecipitates prepared using anti–γ-chain antibodies were immunoblotted with anti-phosphotyrosine antibody 4G10 (γ-pY), or as loading control with anti–γ-chain (γ). Bottom panel: lysates were immunoprecipitated using anti-phosphotyrosine antibody 4G10 and immunoblotted with anti–β-chain antibodies (β-pY); loading controls are lysates immunoblotted with anti–β-chain antibodies (β). WT: littermate control BMMC; KO: PigA-deficient BMMCs; data representative of at least 2 experiments are shown.