Phosphorylation of H2AX, ATM or NBS1 does not require GG-NER in mouse cells. (A) γ-H2AX, p-ATM and p-Nbs1 accumulate at sites of localized UV damage in mouse fibroblasts. (B) No accumulation of NER proteins XPA, XPB and XPC at sites of localized UV damage in mouse fibroblasts that lack GG-NER. Cells were irradiated with 100 J/m2 UV through 5 μm pore filters and cultured for 3 h before fixation. Immunofluorescent labeling was performed using a rabbit or mouse anti-γ-H2AX, anti-CPD, anti-pATM, anti-pNBS1, anti-XPC, anti-XPB and anti-XPA.