title: REV1 mediated mutagenesis in base excision repair deficient mouse fibroblast.
abstract: The DNA polymerase beta (Pol beta) null background renders mouse embryonic fibroblast (MEF) cells base excision repair deficient and hyper-mutagenic upon treatment with the monofunctional alkylating agent, methyl methanesulfonate (MMS). This effect involves an increase in all types of base substitutions, with a modest predominance of G to A transitions. In the present study, we examined the hypothesis that the MMS-induced mutagenesis in the Pol beta null MEF system is due to a lesion bypass mechanism. We studied the effect of RNAi mediated down-regulation of the lesion bypass factor REV1. The steady-state level of REV1 protein was reduced by more than 95% using stable expression of a siRNA construct in a Pol beta null cell line. We found that REV1 expression is required for the MMS-induced mutagenesis phenotype of Pol beta null MEF cells. In contrast, cell survival after MMS treatment is not reduced in the absence of REV1.
authors.affiliation: Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Poltoratsky
authors.forename: Julie K
authors.initials: JK
authors.lastname: Horton
authors.forename: Rajendra
authors.initials: R
authors.lastname: Prasad
authors.forename: Samuel H
authors.initials: SH
authors.lastname: Wilson
mesh_terms: D000818:Animals; D019951:DNA Polymerase beta / Q000235:genetics*; D004260:DNA Repair / Q000235:genetics*; D004259:DNA-Directed DNA Polymerase; D015536:Down-Regulation; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism; D008741:Methyl Methanesulfonate / Q000633:toxicity; D051379:Mice; D016296:Mutagenesis; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000235:genetics; D000099270:Y-Family DNA Polymerases
chemical_list: D019951:DNA Polymerase beta; D004259:DNA-Directed DNA Polymerase; D008741:Methyl Methanesulfonate; D009713:Nucleotidyltransferases; D034741:RNA, Small Interfering; C496086:Rev1 protein, mouse; D000099270:Y-Family DNA Polymerases