Fig. 4: XPF is recruited by TERRA R-loops to generate DNA damage response.

a Representative images of XPF and TRF2 staining in HeLa, WI38-VA, and U2OS cells. U2OS cells were expressing wildtype RNase H1 or catalytic-dead mutant RNase H1. b Quantification of the percentage of TRF2 colocalized with XPF per nucleus in various cell lines and in U2OS cells expressing WT and mutant RNase H1. Percentage of TRF2 co-localized with XPF = (XPF-TRF2 co-localization events / total TRF2 foci). Data of three independent experiments. c Quantification of the percentage of TRF2 colocalized with XPF per nucleus in U2OS cells expressing RCas9-sgRNAs. Data of three independent experiments. Other replicates show similar trends and are provided in the Source Data file. d Representative images of immuno-DNA FISH to detect the colocalization of γH2AX and telomeres in U2OS cells after 72 h transfection with control or XPF siRNAs. Arrowheads indicate colocalization events. e Western blot analysis for XPF in U2OS cells after siRNA knockdown. GAPDH, loading control. f Quantification of γH2AX foci at telomeres. Data of three independent experiments. g Representative images of immuno-DNA FISH to detect the co-localization of RPA70 and telomeres in U2OS cells after transfection with control or XPF siRNAs. Arrowheads indicate colocalization events. Data of three independent experiments. h Quantification of RPA70 foci at telomeres. Data of three independent experiments. a–h Mean or median values of each group shown on the top of figures. P-values by two-sided Mann-Whitney test. Bars, mean ± SEM. n, cell number.