Base excision repair intermediates are mutagenic in mammalian cells.
Base excision repair intermediates are mutagenic in mammalian cells.
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DOI：
10.1093/nar/gki749
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发表时间：
2005
影响因子：
14.9
通讯作者：
Fortini P
中科院分区：
文献类型：
--
作者：
Simonelli V;Narciso L;Dogliotti E;Fortini P
碱基切除修复（BER）是哺乳动物细胞DNA损伤修复的主要途径。该途径导致DNA修复中间体的形成，如果仍然未解决，则导致细胞致死和诱变。为了表征哺乳动物细胞中BER中间体诱导的突变，构建了SV-40衍生的穿梭载体，其在限制性内切酶的识别序列内携带位点特异性损伤。应用限制性片段长度多态性（RFLP）/聚合酶链反应（PCR）技术分析了哺乳动物细胞中无碱基（AP）位点、5′-脱氧核糖-5-磷酸（5′dRp）和3′-[2，3-二氨基-2，3-二脱氧核糖]（3′ ddR5 p）单链断裂（ssb）的突变谱，并应用定量PCR技术估算了突变频率。点突变是发生在所有BER中间体的主要事件。AP位点诱导的突变谱支持“A规则”的证据，也与使用5′相邻碱基指导核苷酸掺入（5′规则）一致。在体内复制5′dRp或3′ ddR5 p ssb后也观察到优先的腺嘌呤插入。我们提供了原始的证据，不仅脱碱基位点，但它的衍生物'面' BER中间体是致突变的，具有类似的突变频率，在哺乳动物细胞。我们的研究结果支持这一假设，无人看管的BER中间体可能是一个持续的威胁基因组的完整性，以及自发的突变源。
Base excision repair (BER) is the main pathway for repair of DNA damage in mammalian cells. This pathway leads to the formation of DNA repair intermediates which, if still unsolved, cause cell lethality and mutagenesis. To characterize mutations induced by BER intermediates in mammalian cells, an SV-40 derived shuttle vector was constructed carrying a site-specific lesion within the recognition sequence of a restriction endonuclease. The mutation spectra of abasic (AP) sites, 5′-deoxyribose-5-phosphate (5′dRp) and 3′-[2,3-didehydro-2,3-dideoxy-ribose] (3′ddR5p) single-strand breaks (ssb) in mammalian cells was analysed by RFLP/PCR and mutation frequency was estimated by quantitative PCR. Point mutations were the predominant events occurring at all BER intermediates. The AP site-induced mutation spectrum supports evidence for the ‘A-rule’ and is also consistent with the use of the 5′ neighbouring base to instruct nucleotide incorporation (5′-rule). Preferential adenine insertion was also observed after in vivo replication of 5′dRp or 3′ddR5p ssb. We provide original evidence that not only the abasic site but also its derivatives ‘faceless’ BER intermediates are mutagenic, with a similar mutation frequency, in mammalian cells. Our findings support the hypothesis that unattended BER intermediates could be a constant threat for genome integrity as well as a spontaneous source of mutations.
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影响因子：
16
作者：
Haracska, L;Kondratick, CM;Prakash, L
通讯作者：
Prakash, L
影响因子：
2.9
作者：
Fortini, P;Pascucci, B;Dogliotti, E
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Dogliotti, E
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作者：
Bennett, SE;Sung, JS;Mosbaugh, DW
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Mosbaugh, DW
影响因子：
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作者：
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通讯作者：
JORGENSEN, TJ
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4.8
作者：
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通讯作者：
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