The XRCC1 phosphate-binding pocket binds poly (ADP-ribose) and is required for XRCC1 function.
The XRCC1 phosphate-binding pocket binds poly (ADP-ribose) and is required for XRCC1 function.
复制标题
XRCC1磷酸盐结合口袋结合了聚（ADP-核糖），是XRCC1函数所必需的。
DOI：
10.1093/nar/gkv623
复制
发表时间：
2015-08-18
影响因子：
14.9
通讯作者：
Caldecott KW
中科院分区：
文献类型：
--
作者：
Breslin C;Hornyak P;Ridley A;Rulten SL;Hanzlikova H;Oliver AW;Caldecott KW
聚 (ADP-核糖) 在 DNA 单链断裂处合成，可以促进支架蛋白 XRCC1 的募集。然而，这一过程的机制和重要性受到了挑战。为了解决这个问题，我们描述了 XRCC1 与聚 (ADP-核糖) 结合的机制，并检查了其对 XRCC1 功能的重要性。我们发现，XRCC1 中央 BRCT1 结构域中的磷酸盐结合口袋是在低 ADP-核糖基化水平下选择性结合聚（ADP-核糖）所必需的，并促进与细胞 PARP1 的相互作用。我们还表明，EGFP-XRCC1 在 UVA 激光、H2O2 诱导的 DNA 损伤处和亚核 PCNA 灶位点处积累需要磷酸盐结合袋，这表明聚（ADP-核糖）在整个基因组的单链断裂处和 DNA 复制应激位点处促进 XRCC1 募集。最后，我们表明，DNA 损伤后，XRCC1 依赖性加速 DNA 单链断裂修复、DNA 碱基切除修复和细胞存活需要磷酸盐结合袋。这些数据支持这样的假设：聚 (ADP-核糖) 合成促进 XRCC1 在 DNA 损伤位点的募集，并且对 XRCC1 功能很重要。
Poly (ADP-ribose) is synthesized at DNA single-strand breaks and can promote the recruitment of the scaffold protein, XRCC1. However, the mechanism and importance of this process has been challenged. To address this issue, we have characterized the mechanism of poly (ADP-ribose) binding by XRCC1 and examined its importance for XRCC1 function. We show that the phosphate-binding pocket in the central BRCT1 domain of XRCC1 is required for selective binding to poly (ADP-ribose) at low levels of ADP-ribosylation, and promotes interaction with cellular PARP1. We also show that the phosphate-binding pocket is required for EGFP-XRCC1 accumulation at DNA damage induced by UVA laser, H2O2, and at sites of sub-nuclear PCNA foci, suggesting that poly (ADP-ribose) promotes XRCC1 recruitment both at single-strand breaks globally across the genome and at sites of DNA replication stress. Finally, we show that the phosphate-binding pocket is required following DNA damage for XRCC1-dependent acceleration of DNA single-strand break repair, DNA base excision repair, and cell survival. These data support the hypothesis that poly (ADP-ribose) synthesis promotes XRCC1 recruitment at DNA damage sites and is important for XRCC1 function.