Roles of specialized DNA polymerases in mutagenesis by 8-hydroxyguanine in human cells
Roles of specialized DNA polymerases in mutagenesis by 8-hydroxyguanine in human cells
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DOI：
10.1016/j.mrfmmm.2010.02.001
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发表时间：
2010-04-01
影响因子：
2.3
通讯作者：
Harashima, Hideyoshi
中科院分区：
文献类型：
--
作者：
Kamiya, Hiroyuki;Yamaguchi, Ayaka;Harashima, Hideyoshi
由于8-OH-Gua与C和A配对的能力，DNA和核苷酸池中8-羟基鸟嘌呤(8-OH-Gua，7，8-二氢-8-氧鸟嘌呤)的形成分别导致G：C->；T：A和A：T->；C：G替换突变。在细胞中复制的DNA被回收，然后被导入一种指示菌株--大肠杆菌。突变分析表明，siRNAs对DNA聚合酶Eta和Zeta的敲除增强了8-OH-Gua：C引起的G：C-和Gt；T：A突变，而DNA聚合酶Eta和Zeta的双重敲除并未进一步增加8-OH-GUA：C引起的突变频率，提示这两种DNA聚合酶的作用途径是相同的。此外，DNA聚合酶Eta的减少使8-OH-Gua：A引起的A：T-&Gt；C：G取代略有减少。这些结果表明，DNA聚合酶ETA和Zeta参与了8-OH-Gua在细胞内的旁路。(C)2010爱思唯尔B.V.保留所有权利。
The formation of 8-hydroxyguanine (8-OH-Gua, 7,8-dihydro-8-oxoguanine) in DNA and in the nucleotide pool results in G:C --> T:A and A:T --> C:G substitution mutations, respectively, due to the ability of 8-OH-Gua to pair with both C and A. In this study, shuttle plasmid DNAs containing 8-OH-Gua paired with C and A in the supF gene were transfected into human 293T cells, in which specialized DNA polymerases were knocked-down. The DNAs replicated in the cells were recovered and then introduced into an indicator strain of Escherichia coli. Mutation analysis indicated that the knock-downs of DNA polymerases eta and zeta by siRNAs enhanced the G:C --> T:A mutations caused by 8-OH-Gua:C. The 8-OH-Gua:C-induced mutation frequency was not further increased by double knock-downs of DNA polymerases eta and zeta suggesting that the two DNA polymerases work in the same pathway. In addition, the reduction of DNA polymerase eta slightly decreased the A:T --> C:G substitutions caused by 8-OH-Gua:A. These results suggest that DNA polymerases eta and zeta are involved in the bypass of 8-OH-Gua in human cells. (C) 2010 Elsevier B.V. All rights reserved.