Figure 3. Pro-apoptotic Bcl-2 proteins and VDAC are not required for ceramide-induced permeabilization of the mitochondrial outer membrane.

a, mitochondria isolated from Bax^−/− Bak^−/− BMK cells (80 µg of mitochondrial protein) were incubated for 10 min with C₁₆-ceramide at the indicated levels. The permeability of the MOM was measured by the complex IV accessibility assay. Data are a representative experiment (from three independent experiments) and are presented as means ± S.D. A two-tailed t test was performed, and ** and *** indicate p values ≤0.01 and 0.005, respectively, when comparing the indicated results with the control (no ceramide addition). b, mitochondria (80µg) isolated from either wild-type (filled circles) or VDAC1 KO (open circles) yeast were incubated for 10 min with the indicated amounts of C₁₆-ceramide, and the permeability of MOM was measured by the complex IV accessibility assay. Data are presented as means ± S.D. from three independent experiments. A two-tailed t test was performed, and ** and *** indicate p values ≤0.01 and 0.005, respectively, when comparing the indicated results with the control (no ceramide addition).