Format

Send to

Choose Destination
J Biol Chem. 2014 Sep 26;289(39):27314-26. doi: 10.1074/jbc.M114.578823. Epub 2014 Aug 13.

DNA2 cooperates with the WRN and BLM RecQ helicases to mediate long-range DNA end resection in human cells.

Author information

1
From the Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland and.
2
the Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 14300 Prague, Czech Republic.
3
From the Institute of Molecular Cancer Research, University of Zurich, 8057 Zurich, Switzerland and the Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 14300 Prague, Czech Republic pjanscak@imcr.uzh.ch.

Abstract

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.

KEYWORDS:

DNA Damage; DNA Helicase; DNA Recombination; DNA Repair; Genomic Instability; RecQ

PMID:
25122754
PMCID:
PMC4175362
DOI:
10.1074/jbc.M114.578823
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center