Fig. 7. Effect of the Bcl-2 mutants on CD95-mediated caspase activation. Cell lysates were prepared 1, 2, 4 and 6 hours after CD95 stimulation (100 ng/ml CH11) and analyzed for caspase processing and PARP cleavage by immunoblotting using antibodies against caspase-8, active caspase-9, active caspase-3 and PARP. The immunoblots show the proforms and p43/41 intermediate cleavage products of caspase-8, the p35 intermediate caspase-9 fragment, the different cleavage products of caspase-3, and the full-length and p85 fragment of PARP. In vector control cells as well as in Bcl-2/
TM- and Bcl-2/ER-expressing cells procaspase-8 was almost completely processed, whereas in cells expressing the wild-type and mitochondrial form of Bcl-2 the processing was attenuated. Caspase-9 and caspase-3 activation as well as PARP cleavage was also delayed in Bcl-2/WT and Bcl-2/MT cells.
