Figure 1.

p53-dependent interaction of Gadd45a, APE1 and PCNA in response to SeMet. (A) Co-immunoprecipitation of Gadd45a, PCNA and APE1 from mock-treated RKO cells and p53 siRNA-treated RKO cells. Anti-Gadd45a antibody (Ab) was used for immunoprecipitation. An anti-PCNA or anti-APE1 primary Ab was used for western blotting. A secondary Ab conjugated to a near-infrared dye was used to detect the bands corresponding to PCNA or APE1. In the cells with reduced p53 expression, the interaction of PCNA and APE1 with Gadd45a was significantly decreased in response to SeMet. (B) APE1, PCNA and Gadd45a were detected using western blotting. GAPDH was used as a marker for equal protein loading.