Role of DNA polymerases η, ι and ζ in UV resistance and UV-induced mutagenesis in a human cell line
Role of DNA polymerases η, ι and ζ in UV resistance and UV-induced mutagenesis in a human cell line
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DOI：
10.1016/j.dnarep.2008.05.012
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发表时间：
2008-09-01
期刊：
影响因子：
3.8
通讯作者：
Weill, Jean-Claude
中科院分区：
文献类型：
--
作者：
Gueranger, Quentin;Stary, Anne;Weill, Jean-Claude
编码 DNA 聚合酶 eta、iota 和 zeta 或 Pol eta 和 Pol iota 的基因已通过伯基特淋巴瘤 BL2 细胞系中的同源重组而失活，从而首次在人类环境中完全抑制这些酶。已经对这些缺陷细胞系的辐照穿梭载体的紫外线敏感性和紫外线诱导诱变进行了分析。双 Pol eta/iota 缺陷细胞系比 Pol eta 缺陷细胞系对紫外线更敏感，并且 Pol eta 缺陷环境特有的突变热点似乎需要 Pol iota 的存在，从而强化了 Pol iota 参与紫外线损伤跨损伤合成和紫外线诱导突变的观点。据报道，Pol zeta 在复制后期损伤修复过程中的作用，这可能解释了当这种聚合酶缺失时观察到的强烈的紫外线敏感性表型。在 Pol C 缺陷细胞系中转染的紫外线照射穿梭载体中观察到了特定的突变模式，与之前报道的 HPRT 位点的诱变相反，其与紫外线诱导的人类皮肤癌中观察到的突变惊人地相似。最后，在没有紫外线诱导病灶的情况下，Pol eta PIP-box 突变体（没有 PCNA 结合域）可以完全恢复 Pol eta 缺陷细胞系的紫外线抵抗力，这表明，正如在 Pol eta 缺陷背景中观察到的 Pol iota 一样，TLS 可能在没有显微镜可见的修复工厂积累的情况下发生。 (c) 2008 Elsevier B.V. 保留所有权利。
Genes coding for DNA polymerases eta, iota and zeta, or for both Pol eta and Pol iota have been inactivated by homologous recombination in the Burkitt's lymphoma BL2 cell line, thus providing for the first time the total suppression of these enzymes in a human context. The UV sensitivities and UV-induced mutagenesis on an irradiated shuttle vector have been analyzed for these deficient cell lines. The double Pol eta/iota deficient cell line was more UV sensitive than the Pol eta-deficient cell line and mutation hotspots specific to the Pol eta-deficient context appeared to require the presence of Pol iota, thus strengthening the view that Pol iota is involved in UV damage translesion synthesis and UV-induced mutagenesis. A role for Pol zeta in a damage repair process at late replicative stages is reported, which may explain the drastic UV-sensitivity phenotype observed when this polymerase is absent. A specific mutation pattern was observed for the UV-irradiated shuttle vector transfected in Pol C-deficient cell lines, which, in contrast to mutagenesis at the HPRT locus previously reported, strikingly resembled mutations observed in UV-induced skin cancers in humans. Finally, a Pol eta PIP-box mutant (without its PCNA binding domain) could completely restore the UV resistance in a Pol eta deficient cell line, in the absence of UV-induced foci, suggesting, as observed for Pol iota in a Pol eta-deficient background, that TLS may occur without the accumulation of microscopically visible repair factories. (c) 2008 Elsevier B.V. All rights reserved.