Regulatory control of DNA end resection by Sae2 phosphorylation

Nat Commun. 2018 Oct 1;9(1):4016. doi: 10.1038/s41467-018-06417-5.

Abstract

DNA end resection plays a critical function in DNA double-strand break repair pathway choice. Resected DNA ends are refractory to end-joining mechanisms and are instead channeled to homology-directed repair. Using biochemical, genetic, and imaging methods, we show that phosphorylation of Saccharomyces cerevisiae Sae2 controls its capacity to promote the Mre11-Rad50-Xrs2 (MRX) nuclease to initiate resection of blocked DNA ends by at least two distinct mechanisms. First, DNA damage and cell cycle-dependent phosphorylation leads to Sae2 tetramerization. Second, and independently, phosphorylation of the conserved C-terminal domain of Sae2 is a prerequisite for its physical interaction with Rad50, which is also crucial to promote the MRX endonuclease. The lack of this interaction explains the phenotype of rad50S mutants defective in the processing of Spo11-bound DNA ends during meiotic recombination. Our results define how phosphorylation controls the initiation of DNA end resection and therefore the choice between the key DNA double-strand break repair mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Cycle
  • DNA Breaks, Double-Stranded*
  • DNA End-Joining Repair / physiology
  • DNA, Fungal / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Endodeoxyribonucleases / metabolism
  • Endonucleases / chemistry
  • Endonucleases / genetics
  • Endonucleases / metabolism*
  • Exodeoxyribonucleases / metabolism
  • Meiosis / genetics
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / metabolism
  • Phosphorylation
  • Protein Binding
  • Protein Multimerization
  • Recombinational DNA Repair / physiology*
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*

Substances

  • DNA, Fungal
  • DNA-Binding Proteins
  • Multiprotein Complexes
  • RAD50 protein, S cerevisiae
  • SAE2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • XRS2 protein, S cerevisiae
  • Endodeoxyribonucleases
  • Endonucleases
  • Exodeoxyribonucleases
  • MRE11 protein, S cerevisiae