Fig. 6.

GFI1’s role in DNA Repair is mediated through PRMT1 activity. a Nuclear extracts were prepared from MEFs expressing an R/K mutant form of MRE11 and wild-type control cells. Extracts were immunoprecipitated for MRE11 and blotted for ADMA. b MEFs expressing an R/K mutant form of MRE11 and wild-type control cells were exposed to 5 Gy IR and allowed to recover for the indicated time. Cells were then lysed and analyzed by alkaline Comet assay. Comet tail moment averages are shown. One of three replicate experiments is shown. Error bars represent s.d. *p < 0.05, **p < 0.01, ***p < 0.001 on a Welch corrected T-test. c GFI1 KO Jurkat cells and parental control cells were treated for 48 h with 500 nM MS023 inhibitor. Nuclear extracts were then immunoprecipitated for MRE11 and blotted for ADMA. d GFI1 KO Jurkat cells and parental control cells (left) and SupT1 overexpressing GFI1 and vector control cells (right) were pre-treated with 500 nM of MS023 inhibitor or vehicle were seeded at 1 million cells per ml and exposed to 5 Gy IR. Cells were counted each following day. Dashed lines show average cell numbers and individual data points of a triplicate experiment are shown. e Cells as in d were exposed to 5 Gy IR and allowed to recover for the indicated time. Cells were then lysed and analyzed by Comet assay as in b. f SupT1 overexpressing GFI1 and vector control cells were electroporated with an siRNA against PRMT1. Electroporated cells were FACS sorted 24 h later. 24 additional hours later, cells were exposed to 5 Gy IR, allowed to recover for the indicated time, then lysed and analyzed by alkaline Comet assay as in b. g GFI1 KO Jurkat cells and parental control cells were treated as in f and analyzed by alkaline Comet assay as in b. h GFI1 KO Jurkat cells and parental control cells were electroporated with a pcDNA3.1 plasmid expressing PRMT1 or a vector control. Electroporated cells were FACS sorted 24 h later. 24 additional hours later, cells were exposed to 5 Gy IR, allowed to recover for the indicated time, then lysed and analyzed by alkaline Comet assay as in b