Fig. 3. HP1γ facilitates homologous recombination of DNA repair.

a Western blotting shows γH2AX and cleaved PARP in WT and BR MM cell treated with BTZ for 24 h. b Levels of γH2AX in WT and BR MM cells treated with camptothecin (CPT, 0–4 μM) for 24 h. c Western blotting shows γH2AX in MM cells with HP1γ KD treated with gradient concentration CPT for 4 h. d Left: immunofluorescence assay shows the level of γH2AX in WT and BR MM cells treated with CPT (2 μM) for 4 h. Right: quantification of γH2AX foci. At least 100 cells were counted, and n = 3 independent experiments. Data represent mean ± S.E.M., student’s t test. e Quantitative assessment of HR and NHEJ activities in HEK293T cells expressing vector control or HP1γ expressing plasmid via flow cytometry assay for the percentage of GFP⁺ cells among RFP⁺ cells. Quantitative data are shown as means ± s.e.m., student’s t test, and n  =  3 (biologically independent experiments). f Co-IP assay shows bilateral interactions between endogenous HP1γ and MDC1. Input, 2% whole cell lysate. g Left: immunofluorescence assay demonstrating the HP1γ recruited to DNA damage regions in MDC1-KD CAG cells. Right: the graph represents the mean intensity of the HP1γ protein on the γH2AX track. Error bars represent S.E.M., n  =  3 (biologically independent experiments), and differences relative to NT-Ctrl were calculated using student’s t test. Source data are provided as a Source data file.