Polμ tumor variants decrease the efficiency and accuracy of NHEJ.
Polμ tumor variants decrease the efficiency and accuracy of NHEJ.
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DOI：
10.1093/nar/gkx625
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发表时间：
2017-09-29
影响因子：
14.9
通讯作者：
Blanco L
中科院分区：
文献类型：
--
作者：
Sastre-Moreno G;Pryor JM;Díaz-Talavera A;Ruiz JF;Ramsden DA;Blanco L
双链断裂（DSB）修复的非同源末端连接（NHEJ）途径通常需要DNA合成来填补断裂端对齐时产生的间隙，这是一项复杂的任务，在人类细胞中由两种特殊的DNA聚合酶Polλ和Polμ完成。目前已经确定Polμ适合修复具有非互补末端的dsb，这是最具挑战性的情况，尽管这种适应的结构基础和生理意义尚未完全了解。在这里，我们证明了两个人类Polμ点突变G174S和R175H，先前在两个不同的肿瘤样本中发现并影响两个相邻残基，限制了Polμ在体外和体内精确NHEJ的效率。此外，我们发现这种限制是NHEJ过程中模板依赖性降低的结果，这使得突变体的错误率更高，这是由于Polμ在dsb中随机结合核苷酸的能力。这些结果突出了Polμ的8 kDa结构域与精确和高效的NHEJ的相关性，以及它对Polμ在2-nt间隙容易出错的行为的贡献。这项工作首次证明了肿瘤中发现的影响Polμ的突变可以改变NHEJ的效率和保真度。
The non homologous end-joining (NHEJ) pathway of double-strand break (DSB) repair often requires DNA synthesis to fill the gaps generated upon alignment of the broken ends, a complex task performed in human cells by two specialized DNA polymerases, Polλ and Polμ. It is now well established that Polμ is the one adapted to repair DSBs with non-complementary ends, the most challenging scenario, although the structural basis and physiological implications of this adaptation are not fully understood. Here, we demonstrate that two human Polμ point mutations, G174S and R175H, previously identified in two different tumor samples and affecting two adjacent residues, limit the efficiency of accurate NHEJ by Polμ in vitro and in vivo. Moreover, we show that this limitation is the consequence of a decreased template dependency during NHEJ, which renders the error-rate of the mutants higher due to the ability of Polμ to randomly incorporate nucleotides at DSBs. These results highlight the relevance of the 8 kDa domain of Polμ for accurate and efficient NHEJ, but also its contribution to the error-prone behavior of Polμ at 2-nt gaps. This work provides the first demonstration that mutations affecting Polμ identified in tumors can alter the efficiency and fidelity of NHEJ.
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影响因子：
2.9
作者：
Dalal, S;Hile, S;Sweasy, JB
通讯作者：
Sweasy, JB
影响因子：
11.4
作者：
Delarue, M;Boulé, JB;Papanicolaou, C
通讯作者：
Papanicolaou, C
影响因子：
16.8
作者：
Garcia-Diaz, M;Bebenek, K;Pedersen, LC
通讯作者：
Pedersen, LC
DOI：
10.1016/j.bbrc.2004.09.002
发表时间：
2004-10-29
影响因子：
3.1
作者：
Fan, W;Wu, XM
通讯作者：
Wu, XM
影响因子：
14.9
作者：
CORPET, F
通讯作者：
CORPET, F