FIG. 8.

Caspase activity is not required for VDAC oligomerization. Cells were preincubated with or without zVAD-fmk (2.5 or 5 μM with HeLa cells and 50 μM with T-REx cells, for 1.5 h), followed by As₂O₃ treatment (30 μM for 17 h). (A and B) Cells were analyzed for VDAC oligomerization (A) and Cyto c release (B). (C) The enzymatic activities of the caspases were followed by measuring the bioluminescent signals using a microplate reader, as described in Materials and Methods. (D) Caspase activity, as reflected by PARP cleavage, was analyzed by immunoblotting. The immunoblot was probed with a rabbit anti-PARP polyclonal antibody. Immunoblotting of actin, as a loading control, is also presented.