Mutational analysis of the C8-guanine adduct of the environmental carcinogen 3-nitrobenzanthrone in human cells: critical roles of DNA polymerases η and κ and Rev1 in error-prone translesion synthesis.
Mutational analysis of the C8-guanine adduct of the environmental carcinogen 3-nitrobenzanthrone in human cells: critical roles of DNA polymerases η and κ and Rev1 in error-prone translesion synthesis.
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人体细胞中环境致癌物 3-硝基苯并酮的 C8-鸟嘌呤加合物的突变分析：DNA 聚合酶 γ 和 γ 以及 Rev1 在易错跨损伤合成中的关键作用。
DOI：
10.1021/bi5007805
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发表时间：
2014
期刊：
影响因子：
2.9
通讯作者：
Basu,AshisK
中科院分区：
文献类型：
--
作者：
Pande,Paritosh;Malik,ChanchalK;Bose,Arindam;Jasti,VijayP;Basu,AshisK
3-硝基苯蒽酮（3-NBA）是一种常见的环境污染物，具有很强的致突变性和致癌性。3-NBA的遗传毒性与其形成DNA加合物的能力有关，包括N-（2′-脱氧鸟苷-8-基）-3-氨基苯并蒽酮（C8-dG-ABA）。为了研究C8-dG-ABA在人类细胞中致突变的分子机制，我们在人胚肾293 T（HEK 293 T）细胞中复制了含有单个C8-dG-ABA的质粒，产生了14%的突变后代。C8-dG-ABA诱发的突变类型主要为G → T > G → A > G → C。HEK 293 T细胞中跨损伤合成（TLS）DNA聚合酶（pols）的siRNA敲低表明，pol η、pol κ、pol I、pol κ和Rev 1各自在跨该加合物的复制中具有作用。TLS的程度随着每次pol敲低而降低，但是TLS水平的最大降低（降低约55%）发生在pol敲低的细胞中。Pol η和pol κ被认为是致突变TLS的主要贡献者，因为当这些pol同时被敲低时，突变频率（MF）降低了70%。Rev 1也是重要的诱变，反映了60%的减少MF Rev 1敲低后，但它可能发挥了非催化作用的物理相互作用与其他两个Y-家族pols。相比之下，pol β似乎参与了病变的无错误旁路，因为MF在pol β敲低细胞中增加了60%。这些结果为C8-dG-ABA加合物的旁路提供了重要的机理见解。
3-Nitrobenzanthrone (3-NBA), a potent mutagen and suspected human carcinogen, is a common environmental pollutant. The genotoxicity of 3-NBA has been associated with its ability to form DNA adducts, includingN-(2′-deoxyguanosin-8-yl)-3-aminobenzanthrone (C8-dG-ABA). To investigate the molecular mechanism of C8-dG-ABA mutagenesis in human cells, we have replicated a plasmid containing a single C8-dG-ABA in human embryonic kidney 293T (HEK293T) cells, which yielded 14% mutant progeny. The major types of mutations induced by C8-dG-ABA were G → T > G → A > G → C. siRNA knockdown of the translesion synthesis (TLS) DNA polymerases (pols) in HEK293T cells indicated that pol η, pol κ, pol ι, pol ζ, and Rev1 each have a role in replication across this adduct. The extent of TLS was reduced with each pol knockdown, but the largest decrease (of ∼55% reduction) in the level of TLS occurred in cells with knockdown of pol ζ. Pol η and pol κ were considered the major contributors of the mutagenic TLS, because the mutation frequency (MF) decreased by 70%, when these pols were simultaneously knocked down. Rev1 also is important for mutagenesis, as reflected by the 60% reduction in MF upon Rev1 knockdown, but it probably plays a noncatalytic role by physically interacting with the other two Y-family pols. In contrast, pol ζ appeared to be involved in the error-free bypass of the lesion, because MF increased by 60% in pol ζ knockdown cells. These results provide important mechanistic insight into the bypass of the C8-dG-ABA adduct.