Figure 7.

INT6 is required for an efficient DDR. (A–C) HeLa cells transfected with siRNAs were treated with NCS (200 ng/ml, 15 min) and immunostained 3 h post-treatment with antibodies to γ-H2AX and Ser343-phosphorylated NBS1 (panel A), conjugated ubiquitin (FK2 antibody, panel B), and BRCA1 (panel C). ~30 cells were acquired for each cell population and experiments were repeated at least twice. Representative confocal images shown were processed as in Fig. 6C. (D) Fluorescence intensities of γ-H2AX, phospho-NBS1, ubiquitin and BRCA1 labeling were measured within the entire nucleus (Total) and within γ-H2AX foci (Foci). Ten nuclei from control cells and from INT6-deficient cells were analyzed for each experiment. Shown are the mean values of fluorescence intensities. Error bars represent standard errors of the mean.