USP11 deubiquitinates XPC at the chromatin following UVB damage ( A, B ) Immunoblot analysis of XPC, USP11, and GAPDH in HaCaT cells transfected with siUSP11 or siNC and treated with or without MG132 (10 µM) 1 h prior to UVB exposure (20 mJ/cm 2 ) (A), 293T WT and ΔUSP11 cells (B) at the indicated times post-UVB (20 mJ/cm 2 ). ( C ) Immunoblot analysis of XPC and histone H3 using chromatin-bound protein fractions from HaCaT cells stably infected with a lentiviral vector expressing shCon or shUSP11 at the indicated times post-sham or -UVB (20 mJ/cm 2 ) irradiation.