Fig. 4
MUS81 cleavage leads to transient DSB accumulation in BRCA2-deficient cells. a Representative comet images of BRCA2-proficient and -deficient cells following treatment with 4 mM HU for 120 min. Scale bar, 50 μm. b Neutral Comet assay monitoring DSB formation in BRCA2-deficient and -proficient U2OS cells following HU treatment for 120 min (no restart) and 15 min after HU removal (restart). Cells were transfected with control siRNA (siNEG) or BRCA2 siRNA. Out of 3 repeats; n ≥ 200 comets scored for each data set. Whiskers the 10th and 90th percentiles. ****P < 0.0001 (Mann–Whitney test). c Neutral Comet assay monitoring DSB formation upon MUS81 depletion or complementation wild-type (MUS81-WT) or catalytically dead (MUS81D338A-D339A) MUS81. Cells were transfected with control siRNA (siNEG), BRCA2 siRNA, MUS81 siRNA, or EXO1 siRNA. MUS81-depleted cells were complemented with wild-type (MUS81-WT) or catalytically dead (MUS81D338A-D339A) MUS81, when indicated. Mirin (50 μM) was added concomitantly with HU treatment, as indicated. Out of 3 repeats; n ≥ 200 comets scored for each data set Whiskers the 10th and 90th percentiles. ****P < 0.0001, *P < 0.05 (Mann–Whitney test)
