REV1介导的碱基切除修复缺陷型小鼠成纤维细胞中的诱变作用。

REV1 mediated mutagenesis in base excision repair deficient mouse fibroblast.

作者信息

Poltoratsky Vladimir, Horton Julie K, Prasad Rajendra, Wilson Samuel H

机构信息

Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, NC 27709, USA.

出版信息

DNA Repair (Amst). 2005 Sep 28;4(10):1182-8. doi: 10.1016/j.dnarep.2005.05.002.

DOI:10.1016/j.dnarep.2005.05.002

PMID:15950550

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.

摘要

DNA聚合酶β（Polβ）基因缺失背景使小鼠胚胎成纤维细胞（MEF）在受到单功能烷化剂甲磺酸甲酯（MMS）处理时碱基切除修复功能缺陷且超诱变。这种效应涉及所有类型碱基替换的增加，其中G到A的转换略有优势。在本研究中，我们检验了以下假设：Polβ基因缺失的MEF系统中MMS诱导的诱变是由于损伤旁路机制。我们研究了RNA干扰介导的损伤旁路因子REV1下调的影响。在Polβ基因缺失的细胞系中使用siRNA构建体的稳定表达，使REV1蛋白的稳态水平降低了95%以上。我们发现，REV1的表达是Polβ基因缺失的MEF细胞MMS诱导的诱变表型所必需的。相比之下，在没有REV1的情况下，MMS处理后的细胞存活率并未降低。