Roles of exonucleases and translesion synthesis DNA polymerases during mitotic gap repair in yeast.
Journal Article (Journal Article)
Transformation-based gap-repair assays have long been used to model the repair of mitotic double-strand breaks (DSBs) by homologous recombination in yeast. In the current study, we examine genetic requirements of two key processes involved in DSB repair: (1) the processive 5'-end resection that is required to efficiently engage a repair template and (2) the filling of resected ends by DNA polymerases. The specific gap-repair assay used allows repair events resolved as crossover versus noncrossover products to be distinguished, as well as the extent of heteroduplex DNA formed during recombination to be measured. To examine end resection, the efficiency and outcome of gap repair were monitored in the absence of the Exo1 exonuclease and the Sgs1 helicase. We found that either Exo1 or Sgs1 presence is sufficient to inhibit gap-repair efficiency over 10-fold, consistent with resection-mediated destruction of the introduced plasmid. In terms of DNA polymerase requirements for gap repair, we focused specifically on potential roles of the Pol ζ and Pol η translesion synthesis DNA polymerases. We found that both Pol ζ and Pol η are necessary for efficient gap repair and that each functions independently of the other. These polymerases may be involved either in the initiation of DNA synthesis from the an invading end, or in a gap-filling process that is required to complete recombination.
Full Text
Duke Authors
Cited Authors
- Guo, X; Jinks-Robertson, S
Published Date
- December 2013
Published In
Volume / Issue
- 12 / 12
Start / End Page
- 1024 - 1030
PubMed ID
- 24210827
Pubmed Central ID
- PMC3870910
Electronic International Standard Serial Number (EISSN)
- 1568-7856
Digital Object Identifier (DOI)
- 10.1016/j.dnarep.2013.10.001
Language
- eng
Conference Location
- Netherlands