14-3-3 proteins repress Exo1-mediated DNA end resection in a Xenopus egg extract.
A, purified recombinant GST, GST-Difopein(WT), and GST-Difopein(MUT) were expressed in and purified from BL21(DE3) E. coli cells. MW, molecular weight. B, effects of GST, GST-Difopein(WT), or GST-Difopein(MUT) on the association of xExo1 with 14-3-3 proteins in the Xenopus NPE. The asterisk denotes a nonspecific band detected by the anti-14-3-3 antibody. IP, immunoprecipitation. C, effects of GST, GST-Difopein(WT) or GST-Difopein(MUT) on DNA end resection in the extract. Vertical lines were added for sample lane identification. D, effects of GST-Difopein(WT) or GST-Difopein(MUT) on DNA end resection in the mock-depleted (depl) and xExo1-depleted or xDna2-depleted extracts. Vertical lines were added for sample lane identification. E, effects of GST-Difopein(WT) or GST-Difopein(MUT) on DNA end resection mediated by added Exo1(WT)-His or Exo1(ΔCR)-His in the extract depleted of both xExo1 and xDna2. Vertical lines were added for sample lane identification.