p75^NTR-induced apoptosis activates the JNK-dependent phosphorylation of Bim_EL and is dependent on Bim_EL. A, PC12 cells were infected with p75^NTR or control adenovirus (LacZ) together with either 5 or 15 MOI of JBD-JIP (J) or control (L) adenovirus. Lysates were immunoblotted with phospho65-Bim or Bim antibody. Aspecific bands recognized by the phospho65-Bim antibody are indicated with an asterisk. B, Lysates of PC12 cells transfected with increasing amounts of control vector (U6), Bim_EL RNA interference plasmid (Bim RNAi), or control RNAi plasmid (Cdk2 RNAi) were immunoblotted with the Bim (top panel), p42 MAP kinase (ERK1/2; middle panel), or actin antibody (bottom panel). C, PC12rtta cells were transfected with the indicated plasmids and subsequently infected with p75^NTR (p75) or control adenovirus (LacZ). Twenty-four hours after infection, cells were fixed and immunostained for cleaved caspase-3. Double asterisk indicates a difference of p < 0.001 between p75^NTR-infected, pCDNA3-transfected cells (bar 8) and mock or LacZ-infected cells (bars 1-7), and p75^NTR-infected, U6-transfected cells (bar 11) and Bim RNAi-transfected cells (bar 12). Single asterisk indicates a difference of p < 0.05 between p75^NTR-infected, pCDNA3-transfected cells (bar 8) and Bim_ELS65A-transfected cells (bar 10), as determined by ANOVA.