Figure 5.

The 89-kDa PARP1 fragment binds AIF via PAR polymers.A, the 89-kDa PARP1 fragment binds AIF. After 4-h exposure to staurosporine, cells were subjected to immunoprecipitation with anti-AIF antibody and then Western blotting using anti-PARP1 antibody. GAPDH was used for a loading control. B, 89-kDa PARP1 fragments bind AIF via PAR polymers in the cytoplasm. PJ34 (10 μM) was added for 30 min before 4-h exposure to staurosporine (300 nM). After subcellular fractionation, cytoplasmic/mitochondrial fractions were subjected to immunoprecipitation with anti-AIF antibody and anti-PARP1 antibody and then Western blotting using anti-PARP1 antibody (left) and anti-AIF antibody (right), respectively. GAPDH and Tom20 were used as cytoplasmic and mitochondrial markers, respectively. AIF, apoptosis-inducing factor; IP, immunoprecipitation; PARP1, poly(ADP-ribose) polymerase 1.