FIGURE 3.

Phosphorylation of ERK, p38, and Akt in wt and lyn^−/− mast cells upon stimulation with low and high concentrations of Ag. Wt and lyn^−/− BMMC were sensitized with IgE and stimulated with 1 or 100 ng/ml DNP₂₁-BSA for the indicated periods. Cell lysates were directly analyzed by immunoblotting with anti-phospho-ERK (Thr²⁰²/Tyr²⁰⁴), anti-phospho-p38 (Thr¹⁸⁰/Tyr¹⁸²), or anti-phospho-Akt (Ser⁴⁷³), followed by reprobing the same blot with anti-ERK, anti-p38, or pAkt, respectively. Relative band intensities of ERK1, p38, and Akt phosphorylation normalized against their amounts are shown. Phosphorylation induced at 1 ng/ml DNP₂₁-BSA for 5 min is set at 1.0. *, p < 0.1. Results shown are representative of three experiments using independent sets of BMMCs.