Abstract—

5-Methyl-2'-deoxycytidine (mC) and the product of its controlled oxidation, 5-hydroxymethyl-2'-cytidine (hmC), play a key role in the epigenetic regulation of gene expression, the cell differentiation, and the carcinogenesis. Due to spontaneious deamination, genomic CpG sites containing mC and hmC serve as mutagenesis hotspots. In addition, error-prone translesion and reparative DNA polymerases may serve as additional source of mutations in the lesion-containing regions with CpG sites. In the present work, we performed in vitro analysis of the accuracy of nucleotide incorporation opposite to mC and hmC by human DNA polymerases Polβ, Polλ, Polη, Polι, Polκ and primase polymerase PrimPol. The results of the study show a high accuracy of copying mC and hmC by the reparative DNA polymerases Polβ and Polλ, while Polη, Polι, Polκ, and PrimPol copied mC and hmC with less accuracy evident by incorporation of dAMP and dTMP. The same spectrum of error-prone dNMP incorporation was also noted at sites with unmodified cytosines.

中文翻译：

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5-甲基-2'-脱氧胞苷和5-羟甲基-2'-脱氧胞苷在与人类侵染和修复性DNA聚合酶反应中的模板性质

摘要-

5-甲基-2'-脱氧胞苷（mC）及其受控氧化产物5-羟甲基-2'-胞苷（hmC）在基因表达的表观遗传调控，细胞分化和癌变中起关键作用。由于自发的脱氨基作用，含有mC和hmC的基因组CpG位点可作为诱变热点。此外，容易出错的转移和修复性DNA聚合酶可作为含CpG位点的含病变区域中突变的额外来源。在目前的工作中，我们进行了人DNA聚合酶Polβ，Polλ，Polη，PolI，Polκ和primase聚合酶PrimPol与mC和hmC相反的核苷酸掺入准确性的体外分析。研究结果表明，修复性DNA聚合酶Polβ和Polλ复制mC和hmC的准确性很高，而Polη，Polι，Polκ，PrimPol通过并入dAMP和dTMP明显降低了mC和hmC的复制准确性。在未修饰胞嘧啶的位点也发现了容易出错的dNMP掺入的相同光谱。