Nonsense-mediated decay regulates key components of homologous recombination

Nucleic Acids Res. 2016 Jun 20;44(11):5218-30. doi: 10.1093/nar/gkw182. Epub 2016 Mar 21.


Cells frequently experience DNA damage that requires repair by homologous recombination (HR). Proteins involved in HR are carefully coordinated to ensure proper and efficient repair without interfering with normal cellular processes. In Saccharomyces cerevisiae, Rad55 functions in the early steps of HR and is regulated in response to DNA damage through phosphorylation by the Mec1 and Rad53 kinases of the DNA damage response. To further identify regulatory processes that target HR, we performed a high-throughput genetic interaction screen with RAD55 phosphorylation site mutants. Genes involved in the mRNA quality control process, nonsense-mediated decay (NMD), were found to genetically interact with rad55 phospho-site mutants. Further characterization revealed that RAD55 transcript and protein levels are regulated by NMD. Regulation of HR by NMD extends to multiple targets beyond RAD55, including RAD51, RAD54 and RAD57 Finally, we demonstrate that loss of NMD results in an increase in recombination rates and resistance to the DNA damaging agent methyl methanesulfonate, suggesting this pathway negatively regulates HR under normal growth conditions.

MeSH terms

  • Cluster Analysis
  • Computational Biology / methods
  • DNA Damage
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Epistasis, Genetic
  • Gene Expression Regulation, Fungal
  • Homologous Recombination*
  • Mutation
  • Nonsense Mediated mRNA Decay*
  • Phosphorylation
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Signal Transduction
  • Transcription, Genetic


  • DNA-Binding Proteins
  • RAD55 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins