Fig. 9: ALC1 regulates UV-induced chromatin expansion and PAR response shut-down.
From: XPC–PARP complexes engage the chromatin remodeler ALC1 to catalyze global genome DNA damage repair
a Outline of the sequential UV-C and UV-A laser irradiation approach and representative images of PAGFP-H2A and mCherry-DDB2 in the indicated cell lines at 3 s and 60 s after sequential irradiation. Additional irradiation controls are shown in Fig. S6c, d. b Quantification of the UV-induced expansion of PAGFP-H2A tracks marked by mCherry-DDB2 recruitment at 60 s after sequential irradiation. The normalized expansion of each biological replicate is depicted as a point, while the bar represents the median from three independent experiments. The expansion in each experiment for PARP1-KO (blue dots) and PARP2-KO (red dots) was normalized to the isogenic WT control (black dots), while ALC1-KO (purple dots) was normalized to the isogenic WT (FRT) control (black dots). >38 cells were analyzed in 3 independent experiments. c Representative images and d quantification of poly-(ADP-ribose) (PAR) levels 10, 20, and 30 minutes after local UV-C irradiation (30 J/m2) by immunofluorescence (Trevigen, 4335-MC-100) in U2OS WT, ALC1-KO, ALC1-KO + GFP-ALC1, ALC1-KO + GFP-ALC1 E175Q. Quantification of XPC levels in the same cells is shown in Fig. S6e. The median of each biological replicate is depicted as a colored point, while the bar represents the median of all data points. >80 cells were analyzed per condition from three independent experiments. The scale bar in a, c is 5 µm. e Model of PARP1, PARP2, and ALC1 influence on XPC-dependent repair.
