RNF168 resides in detergent-insoluble structures and interacts with the histone core. A) Before fixing, HeLa cells transfected with the GFP-tagged indicated constructs or the vector alone, were pre-treated (right panels) or not (left panels) with Triton X-100. The nucleus was stained with To-Pro 3. B) To test RNF168 capability to associate with histones, we performed in vitro pull down assay on cell lysate derived from 293T cells expressing the GFP-tagged forms of histones H2A, H2B, H3 and H4. To detect histone binding, the associated proteins were resolved by SDS-PAGE and analysed by anti-GFP immunoblot. To normalize for equal loading, Ponceau-red staining is shown.