iPLA2 attenuates the release of cytochrome c, Smac/DIABLO, and AIF from mitochondria. A, effect of iPLA2 on cytochrome c in INS-1 cells. INS-1 and iPLA2-INS cells were treated with 1 μM STS for increasing times, and cytoplasmic (Cyt.) and mitochondrial (Mitoch) fractions were prepared with a mitochondria/cytosol fractionation kit. The samples from each fraction were analyzed by Western blot for cytochrome c. B, effect of iPLA2 on Smac/DIABLO and AIF in INS-1 cells. Samples were prepared analyzed as in A for Smac/DIABLO and AIF in both fractions.