Figure 7.

NTH1 and XRCC1 recruitment to chromatin after oxidative stress is dependent on mediator and cohesin. (A) Cells co-transfected with OGG1-mcherry and either NTH1-GFP or XRCC1-GFP were exposed to KBrO₃ and after 3 h of recovery soluble proteins were washed by CSK pre-extraction. Both NTH1 and XRCC1 perfectly co-localize with OGG1 in the chromatin fraction. (B) Levels of NTH1-GFP and XRCC1-GFP associated to the chromatin fraction were quantified three hours after exposure to KBrO₃ in cells transfected with siRNA against MED14 or SMC3 and compared to the control cells. More than 300 cells were analysed from two independent experiments. Error bars indicate SEM. Statistical analysis involved a Kruskal–Wallis test. (****) P < 0.0001; (***) 0.0005. Scale bar 5 μm