Skip to main content
. Author manuscript; available in PMC: 2016 Mar 3.
Published in final edited form as: Oncogene. 2014 Dec 1;34(36):4791–4796. doi: 10.1038/onc.2014.394

Figure 4. Overexpression of USP7 facilitates UV-induced PCNA ubiquitination by stabilizing Polη.

Figure 4

Cells were transiently transfected with empty vector (EV) or vector encoding FLAG-tagged USP7 for 24 h. The transfected cells, without or with UV (20 J/m2) irradiation, were harvested at indicated post-irradiation time points. The protein levels in cell lysates were detected by Western blotting with their respective antibodies. S and L, respectively, stand for short and long film exposures, which were necessary to depict uniform loading and changes in low abundant ubiquitinated PCNA (ubPCNA). Quantitative analysis of PCNA ubiquitination: The ratio of ubPCNA/PCNA at different time points were normalized to the ratio of XP30RO-EGFP-Polη cells at 2 h post-irradiation, which set as 1. Error bars represent ±SE of three independent Western blot experiments. (A) XP30RO-EGFP-Polη. (B) XP30RO cells. (C) HCT116 cells transfected with empty vector (EV) or vector encoding FLAG-tagged USP7-WT for 24 h. (D) HCT116 cells transfected with empty vector (EV) or vector encoding FLAG-tagged USP7-CS for 24 h.