Figure 2.

DNA damage-dependent polySUMOylation of Pol η. A, U2OS or U2OS/GFP-Pol η cells were left untreated or exposed to UV, lysed, and subjected to GFP immunoprecipitation (IP) under denaturing conditions followed by immunoblotting (IB) with the indicated antibodies. B, as in A, but using SUMO1 antibody for immunoblotting. C, Pol η polySUMOylation at different time points after UV exposure was analyzed as in A. D, U2OS/GFP-Pol η cells treated or not with RAD18 siRNA and UV as indicated were processed for analysis of Pol η polySUMOylation as in A. E, as in A, using the indicated PIAS1 siRNAs. F, U2OS or U2OS/GFP-Pol η cells left untreated or exposed to UV were lysed and subjected to GFP IP under native conditions and immunoblotted with the indicated antibodies.