SFPQ•NONO and XLF function separately and together to promote DNA double-strand break repair via canonical nonhomologous end joining.
SFPQ•NONO and XLF function separately and together to promote DNA double-strand break repair via canonical nonhomologous end joining.
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DOI：
10.1093/nar/gkw1209
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发表时间：
2017-02-28
影响因子：
14.9
通讯作者：
Dynan WS
中科院分区：
文献类型：
--
作者：
Jaafar L;Li Z;Li S;Dynan WS
两种相关哺乳动物蛋白质SFPQ和NONO的复合物通过典型的非同源末端连接（c-NHEJ）途径促进DNA双链断裂修复。然而，其作用机制尚未完全了解。在这里，我们描述了一种改进的SFPQ·NONO依赖的体外末端连接试验。我们使用该系统来证明SFPQ·NONO复合物在体外替代核心c-NHEJ因子XLF。结果与SFPQ·NONO促进DNA底物的序列独立配对的模型一致，尽管在细节上与XLF不同。虽然SFPQ·NONO和XLF在体外功能冗余，但shRNA介导的敲除实验表明NONO和XLF都是基于细胞的测定中有效末端连接和辐射抗性所必需的。此外，NONO的敲低使细胞对链间交联剂顺铂敏感，而XLF的敲低则不会，并且确实抑制了NONO缺乏的作用。这些发现表明，除了在体外发现的DNA配对之外，每种蛋白质都具有一种或多种独特的活性，这些活性有助于在更复杂的细胞环境中进行DNA修复。SFPQ·NONO复合物含有一个RNA结合结构域，先前的工作已经证明了在RNA代谢中的多种作用。因此，在基于细胞的测定中揭示的NONO的额外修复功能可能涉及RNA相互作用是合理的。
A complex of two related mammalian proteins, SFPQ and NONO, promotes DNA double-strand break repair via the canonical nonhomologous end joining (c-NHEJ) pathway. However, its mechanism of action is not fully understood. Here we describe an improved SFPQ•NONO-dependent in vitro end joining assay. We use this system to demonstrate that the SFPQ•NONO complex substitutes in vitro for the core c-NHEJ factor, XLF. Results are consistent with a model where SFPQ•NONO promotes sequence-independent pairing of DNA substrates, albeit in a way that differs in detail from XLF. Although SFPQ•NONO and XLF function redundantly in vitro, shRNA-mediated knockdown experiments indicate that NONO and XLF are both required for efficient end joining and radioresistance in cell-based assays. In addition, knockdown of NONO sensitizes cells to the interstrand crosslinking agent, cisplatin, whereas knockdown of XLF does not, and indeed suppresses the effect of NONO deficiency. These findings suggest that each protein has one or more unique activities, in addition to the DNA pairing revealed in vitro, that contribute to DNA repair in the more complex cellular milieu. The SFPQ•NONO complex contains an RNA binding domain, and prior work has demonstrated diverse roles in RNA metabolism. It is thus plausible that the additional repair function of NONO, revealed in cell-based assays, could involve RNA interaction.
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影响因子：
1.6
作者：
Ahmed EA;Vélaz E;Rosemann M;Gilbertz KP;Scherthan H
通讯作者：
Scherthan H
影响因子：
10.3
作者：
Liu, Pei Y.;Erriquez, Daniela;Liu, Tao
通讯作者：
Liu, Tao
影响因子：
14.9
作者：
Li S;Kuhne WW;Kulharya A;Hudson FZ;Ha K;Cao Z;Dynan WS
通讯作者：
Dynan WS
DOI：
10.1073/pnas.94.9.4267
发表时间：
1997-04-29
影响因子：
11.1
作者：
Cary, RB;Peterson, SR;Chen, DJ
通讯作者：
Chen, DJ
影响因子：
14.9
作者：
Knott GJ;Bond CS;Fox AH
通讯作者：
Fox AH