BH3-only and multidomain proapoptotic proteins sequestered by Bcl-2 were displaced by ABT-737. (A) Immunoblot analysis of the indicated proteins (70 μg). Actin was used as a loading control. (B) Immunoprecipitation of KMS-12-PE or XG-5 cell lysates (300 μg) using the indicated antibodies. The immunoprecipitates were analyzed for the presence of antiapoptotic, BH3-only proteins or multidomain proapoptotic proteins. The asterisk (*) corresponds to the immunoglobulin light chain. (C) Bcl-2 immunoprecipitation of KMS-12-PE or XG-5 cell lysates treated or not with 40nM ABT-737 for both 1 and 6 hours. The immunoprecipitates and the outputs (IP supernatants) were analyzed for the presence for the indicated proteins by immunoblotting.