Fig. 2: SART3 promotes DSB repair.

a, b U2OS cells stably expressing GFP or GFP-SART3 were transfected with siNC or siSART3-1, followed by treatment with DMSO or ETO (10 µM for 2 h, and allowed to repair 0.5 h). The levels of γH2AX were analyzed by immunoblotting (a). U2OS cells were transfected with siNC or siSART3-1/3, followed by treatment with DMSO or ETO (10 µM for 2 h) and further recovery for 0.5, 3 or 8 h. The samples were analyzed by immunoblotting using indicated antibodies. b The intensity of γH2AX was quantified by Image J software and normalized. c U2OS-DR-GFP cells stably expressing Flag-SART3 or Flag were transfected with siNC, siSART3-1 or siCtIP. 24 h later, cells were infected with I-SceI lentivirus. Percentage of GFP-positive cells was quantitated by FACS at 48 h after virus infection (top). The SART3 knockdown efficiency was verified by immunoblotting (bottom). d–g U2OS cells stably expressing either GFP-SART3 or GFP were transfected with siNC or siSART3, followed by treatment with indicated concentrations of ETO for 24 h (e), CPT for 1 h (f), HU for 2 h (g) or Olaparib for 48 h (h). The cells were further incubated for colony formation. SiSART3 indicates siSART3-1, if not specified. In (c–g), error bars represent mean ± SEM (N = 3 independent experiments), and p values were calculated using unpaired two-tailed Student’s t test (c) or one-way ANOVA analysis with Tukey test (d–g). Source data are provided as a Source Data file.