Cul4a as a New Interaction Protein of PARP1 Inhibits Oxidative Stress-Induced H9c2 Cell Apoptosis

Figure 5

PARP1 was a novel Cul4a-interacting protein, and the interaction was enhanced under oxidative stress. (a) Coimmunoprecipitation (co-IP) and western blotting (IP-western) using anti-PARP1 antibody or negative control IgG and Protein A/G immunoprecipitation magnetic beads followed by anti-Cul4a western blot were performed to identify endogenous interaction between PARP1 and Cul4a. (b) Anti-Flag antibody and Protein A/G immunoprecipitation magnetic beads followed by anti-PARP1 western blot were performed to identify semiexogenous interaction between Flag-Cul4a and PARP1. (c) Endogenous interaction between PARP1 and Cul4a was enhanced by treatment of 200 μM H₂O₂ for 2 h, which were evaluated by coimmunoprecipitation using anti-PARP1 antibody. (d) Semiexogenous interaction between Flag-Cul4a and PARP1 was enhanced by treatment of 200 μM H₂O₂ for 2 h, which were evaluated by coimmunoprecipitation using anti-Flag antibody. GAPDH was used as a loading control. Cul4a: cullin 4a; PARP1: poly (ADP-ribose) polymerase-1; GAPDH: glyceraldehyde-3-phosphate dehydrogenase.

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