FIGURE 2.

Induction of apoptosis by Cholix. A, Cholix treatment induced cleavage of caspases and PARP. Cells (1 × 10⁵ cells/well) in a 12-well dish were grown for 24 h and then incubated with wild-type (WT) or mutant (MT) Cholix (10 μg/ml) for the indicated times. Lysates were collected from cells and resolved by immunoblotting (IB) to detect the indicated caspase cleavage or PARP cleavage. GAPDH was used as a loading control. B, cells were incubated with WT or MT Cholix at different concentrations for 18 h and analyzed for induction of caspase-7, caspase-9, or PARP cleavage. C, HeLa cells were incubated with WT or MT Cholix (10 μg/ml) for 18 h, and then the cytosolic fraction was collected as described previously (18). Cytochrome c release into cytosol was detected using an anti-cytochrome c antibody. Data are representative of three separate experiments.