The 5'-3' resection of DNA ends is a prerequisite for the repair of DNA double strand breaks by homologous recombination, microhomology-mediated end joining, and single strand annealing. Recent studies in yeast have shown that, following initial DNA end processing by the Mre11-Rad50-Xrs2 complex and Sae2, the extension of resection tracts is mediated either by exonuclease 1 or by combined activities of the RecQ family DNA helicase Sgs1 and the helicase/endonuclease Dna2. Although human DNA2 has been shown to cooperate with the BLM helicase to catalyze the resection of DNA ends, it remains a matter of debate whether another human RecQ helicase, WRN, can substitute for BLM in DNA2-catalyzed resection. Here we present evidence that WRN and BLM act epistatically with DNA2 to promote the long-range resection of double strand break ends in human cells. Our biochemical experiments show that WRN and DNA2 interact physically and coordinate their enzymatic activities to mediate 5'-3' DNA end resection in a reaction dependent on RPA. In addition, we present in vitro and in vivo data suggesting that BLM promotes DNA end resection as part of the BLM-TOPOIIIα-RMI1-RMI2 complex. Our study provides new mechanistic insights into the process of DNA end resection in mammalian cells.
- MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- DNA-helikasy genetika metabolismus MeSH
- DNA genetika metabolismus MeSH
- dvouřetězcové zlomy DNA * MeSH
- enzymy opravy DNA genetika metabolismus MeSH
- exodeoxyribonukleasy genetika metabolismus MeSH
- genetická epistáze fyziologie MeSH
- HEK293 buňky MeSH
- helikasy RecQ genetika metabolismus MeSH
- lidé MeSH
- multienzymové komplexy genetika metabolismus MeSH
- ubikvitin aktivující enzymy genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
