Journal: Nucleic Acids Research
Article Title: Genome-wide CRISPR screens identify the EXO1-CAF-1 pathway suppressing R-loop-associated DNA damage
doi: 10.1093/nar/gkag226
Figure Lengend Snippet: Concomitant depletion of EXO1 and CHAF1A causes the accumulation of R-loop-associated DNA damage. ( A ) S9.6-γH2AX PLA experiments showing increased R-loop-associated DNA damage in HeLa cells with concomitant inactivation of EXO1 and CHAF1A. RNAseH1 overexpression suppresses the PLA signal, indicating that it derives from R-loops. At least 100 cells were quantified for each condition. Bars indicate the mean values, error bars represent standard errors of the mean, and asterisks indicate statistical significance ( t -test, two-tailed, unpaired). The siCHAF1A/siControl mean ratios are also presented. ( B–D ) γH2AX immunofluorescence showing that CHAF1A depletion causes increased DNA damage in both EXO1-knockout lines compared to WT HeLa cells, which is suppressed by RNaseH1 overexpression. Quantifications ( B, D ) and representative micrographs with scale bars representing 10 µm ( C ) are shown. At least 100 cells were quantified for each condition. Bars indicate the mean values, error bars represent standard errors of the mean, and asterisks indicate statistical significance ( t -test, two-tailed, unpaired). ( E–G ) Neutral comet assays showing that CHAF1A depletion causes increased DSB formation in both EXO1-knockout lines compared to WT HeLa cells, which is suppressed by RNaseH1 overexpression. Quantifications ( E, G ) and representative micrographs with scale bars representing 10 µm ( F ) are shown. At least 100 comets were quantified for each sample. The median values are marked on the graph, and asterisks indicate statistical significance (Mann–Whitney, two-tailed).
Article Snippet: Antibodies used were: S9.6 (Kerafast ENH001), double-stranded DNA (dsDNA; Novus NBP3-07302), γH2AX (Abcam ab2893), EXO1 (Novus NBP2-16391), and CHAF1A (Cell Signaling Technology 5480s).
Techniques: Over Expression, Two Tailed Test, Immunofluorescence, Knock-Out, MANN-WHITNEY