Multiple roles of Rev3, the catalytic subunit of pole in maintaining genome stability in vertebrates
Multiple roles of Rev3, the catalytic subunit of pole in maintaining genome stability in vertebrates
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DOI：
10.1093/emboj/cdg308
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发表时间：
2003-06-16
期刊：
影响因子：
11.4
通讯作者：
Takeda, S
中科院分区：
文献类型：
--
作者：
Sonoda, E;Okada, T;Takeda, S
翻译DNA合成（TLS）和同源DNA重组（HR）是复制后修复（PRR）的两种主要途径。酿酒酵母REV3基因编码DNA聚合酶的催化亚基，参与诱变TLS。为了研究REV3在脊椎动物中的作用，我们在鸡DT40细胞中破坏了该基因。REV3（-/-）细胞很敏感。对紫外线、甲磺酸甲酯（MMS）、顺铂和电离辐射（IR）等多种dna损伤剂的影响，与其在TLS中的作用一致。有趣的是，在G(2)期IR后，REV3（-/-）细胞表现出基因靶向效率降低，在随后的M期染色体断裂水平显著增加，这表明REV3参与了hr介导的双链断裂修复。即使在没有外源性基因毒性胁迫的情况下，REV3（-/-）细胞的姐妹染色单体交换事件和染色体断裂也显著增加。此外，与HR相关的基因REV3和RAD54双突变体具有合成致死性。综上所述，Rev3在PRR中起着关键作用，它解释了在复制过程中自然发生的内源性损伤和诱导损伤下的存活。
Translesion DNA synthesis (TLS) and homologous DNA recombination (HR) are two major postreplicational repair (PRR) pathways. The REV3 gene of Saccharomyces cerevisiae encodes the catalytic subunit of DNA polymerase, which is involved in mutagenic TLS. To investigate the role of REV3 in vertebrates, we disruped the gene in chicken DT40 cells. REV3(-/-) cells are sensitive. to various DNA-damaging agents, including UV, methyl methanesulphonate (MMS), cisplatin and ionizing radiation (IR), consistent with its role in TLS. Interestingly, REV3(-/-) cells showed reduced gene targeting efficiencies and significant increase in the level of chromosomal breaks in the subsequent M phase after IR in the G(2) phase, suggesting the involvement of Rev3 in HR-mediated doublestrand break repair. REV3(-/-) cells showed significant increase in sister chromatid exchange events and chromosomal breaks even in the absence of exogenous genotoxic stress. Furthermore, double mutants of REV3 and RAD54, genes involved in HR, are synthetic lethal. In conclusion, Rev3 plays critical roles in PRR, which accounts for survival on naturally occurring endogenous as well as induced damages during replication.