FIGURE 2.

Bim degradation in MEF cells is associated with an increase interaction between TRIM2 and Bim. MEF cells were serum-starved for 24 h and then incubated for 1 h with serum and emetine. A, lysates were immunoblotted for phospho-p42/p44 MAPK and Bim protein levels. B, immunoprecipitation of TRIM2 with either GST-Bim or GST3ABim following serum stimulation (Stim) of MEF cells. Pulldown is determined by immunoblotting precipitated proteins with a GST-specific antibody. Representative blots of two independent observations are shown. C, MEF cells were incubated with TPA for 1 h, and cell lysates were prepared. Some cells were co-incubated with 10 μm U0126. Bim protein levels and phospho-MAPK levels were determined by immunoblotting. D, lysates from TPA-treated MEF cells were subjected to endogenous Bim immunoprecipitation. Precipitated proteins were immunoblotted for TRIM2 with a TRIM2-specific antibody (Novus). TRIM2 pulldown with Bim increased following incubation of MEF cells with TPA and was reduced by U0126.