FIG. 1.

Knockdown of Bif-1 prevents Bax conformational change. HeLa cells were transfected with siRNAs targeting Bif-1 (siBif-1) or control GFP (siGFP) and subjected to the following analyses. (A) Immunoblot analysis with anti-Bif-1 monoclonal antibody (Imgenex) revealed that Bif-1 protein expression was significantly reduced by transfection with siBif-1 duplexes. (B to D) SiRNA-transfected cells were exposed to either 1 μM ADR for 12 h, 0.5 μM STS for 6 h, or 1 mM methyl methanesulfonate (MMS) for 10 h. Bax conformational change was determined by immunoprecipitation (IP) with anti-Bax 6A7 monoclonal antibody (B), as well as by immunofluorescence staining (green) with anti-Bax N20 polyclonal antibody (C). The N20-positive cells in panel C were counted under fluorescence microscopy (D). The data shown are means plus standard deviations (n = 3). The nuclear morphology was examined by DAPI (blue) staining.