The dCMP transferase activity of yeast Rev1 is biologically relevant during the bypass of endogenously generated AP sites.

Published

Journal Article

The bypass of AP sites in yeast requires the Rev1 protein in addition to the Pol ζ translesion synthesis DNA polymerase. Although Rev1 was originally characterized biochemically as a dCMP transferase during AP-site bypass, the relevance of this activity in vivo is unclear. The current study uses highly sensitive frameshift- and nonsense-reversion assays to monitor the bypass of AP sites created when uracil is excised from chromosomal DNA. In the frameshift-reversion assay, an unselected base substitution frequently accompanies the selected mutation, allowing the relative incorporation of each of the four dNMPs opposite endogenously created AP sites to be inferred. Results with this assay suggest that dCMP is the most frequent dNMP inserted opposite uracil-derived AP sites and demonstrate that dCMP insertion absolutely requires the catalytic activity of Rev1. In the complementary nonsense-reversion assay, dCMP insertion likewise depended on the dCMP transferase activity of Rev1. Because dAMP insertion opposite uracil-derived AP sites does not revert the nonsense allele and hence could not be detected, it also was possible to detect low levels of dGMP or dTMP insertion upon loss of Rev1 catalytic activity. These results demonstrate that the catalytic activity of Rev1 is biologically relevant and is required specifically for dCMP insertion during the bypass of endogenous AP sites.

Full Text

Duke Authors

Cited Authors

  • Kim, N; Mudrak, SV; Jinks-Robertson, S

Published Date

  • December 10, 2011

Published In

Volume / Issue

  • 10 / 12

Start / End Page

  • 1262 - 1271

PubMed ID

  • 22024240

Pubmed Central ID

  • 22024240

Electronic International Standard Serial Number (EISSN)

  • 1568-7856

Digital Object Identifier (DOI)

  • 10.1016/j.dnarep.2011.09.017

Language

  • eng

Conference Location

  • Netherlands