Functional overlap between the structure-specific nucleases Yen1 and Mus81-Mms4 for DNA-damage repair in S. cerevisiae

DNA Repair (Amst). 2010 Apr 4;9(4):394-402. doi: 10.1016/j.dnarep.2009.12.017. Epub 2010 Jan 27.


In eukaryotic cells, multiple DNA repair mechanisms respond to a wide variety of DNA lesions. Homologous recombination-dependent repair provides a pathway for dealing with DNA double-strand breaks and replication fork demise. A key step in this process is the resolution of recombination intermediates such as Holliday junctions (HJs). Recently, nucleases from yeast (Yen1) and human cells (GEN1) were identified that can resolve HJ intermediates, in a manner analogous to the E. coli HJ resolvase RuvC. Here, we have analyzed the role of Yen1 in DNA repair in S. cerevisiae, and show that while yen1Delta mutants are repair-proficient, yen1Delta mus81Delta double mutants are exquisitely sensitive to a variety of DNA-damaging agents that disturb replication fork progression. This phenotype is dependent upon RAD52, indicating that toxic recombination intermediates accumulate in the absence of Yen1 and Mus81. After MMS treatment, yen1Delta mus81Delta double mutants arrest with a G2 DNA content and unsegregated chromosomes. These findings indicate that Yen1 can act upon recombination/repair intermediates that arise in MUS81-defective cells following replication fork damage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • DNA Breaks, Double-Stranded
  • DNA Damage*
  • DNA Repair*
  • DNA, Fungal / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Endonucleases / genetics
  • Endonucleases / metabolism*
  • Flap Endonucleases / genetics
  • Flap Endonucleases / metabolism*
  • Holliday Junction Resolvases / genetics
  • Holliday Junction Resolvases / metabolism*
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*


  • DNA, Fungal
  • DNA-Binding Proteins
  • Saccharomyces cerevisiae Proteins
  • Endonucleases
  • Flap Endonucleases
  • MUS81 protein, S cerevisiae
  • Holliday Junction Resolvases
  • Yen1 protein, S cerevisiae
  • MMS4 protein, S cerevisiae