Damage response of XRCC1 at sites of DNA single strand breaks is regulated by phosphorylation and ubiquitylation after degradation of poly(ADP-ribose).
Damage response of XRCC1 at sites of DNA single strand breaks is regulated by phosphorylation and ubiquitylation after degradation of poly(ADP-ribose).
复制标题
DOI：
10.1242/jcs.128272
复制
发表时间：
2013-10-01
影响因子：
4
通讯作者：
Lan L
中科院分区：
文献类型：
--
作者：
Wei L;Nakajima S;Hsieh CL;Kanno S;Masutani M;Levine AS;Yasui A;Lan L
单链断裂（SSBs）是最常见的DNA氧化损伤类型，它与衰老和许多遗传疾病有关。用于修复SSBs的支架蛋白XRCC1在PARP合成的聚adp核糖（pAR）位点上积累，但在pAR降解后保留在SSBs位点上。在pAR降解后，XRCC1如何对SSBs作出反应，以及这如何影响修复进程，目前尚不清楚。我们发现XRCC1与pAR分离，并根据其BRCTII结构域和PARG的功能转移到SSBs的位点。此外，XRCC1的磷酸化也是XRCC1适当解离动力学所必需的，因为(1)与野生型XRCC1相比，XRCC1磷酸化位点突变（X1 pm）导致XRCC1在SSB位点滞留的时间更长；(2) XRCC1的高效多泛素化需要磷酸化。有趣的是，XRCC1的一个突变体LL360/361DD，可以消除pAR结合，显示出泛素化的显著上调，这表明XRCC1的pARylation阻止了多泛素化。我们还发现修复蛋白DNA聚合酶β、PNK、APTX、PCNA和连接酶I的动态受到XRCC1结构域的调节。综上所述，XRCC1的动态损伤反应依赖于活细胞中聚adp核糖基化、磷酸化和泛素化的修饰。
Single-strand breaks (SSBs) are the most common type of oxidative DNA damage and they are related to aging and many genetic diseases. The scaffold protein for repair of SSBs, XRCC1, accumulates at sites of poly(ADP-ribose) (pAR) synthesized by PARP, but it is retained at sites of SSBs after pAR degradation. How XRCC1 responds to SSBs after pAR degradation and how this affects repair progression are not well understood. We found that XRCC1 dissociates from pAR and is translocated to sites of SSBs dependent on its BRCTII domain and the function of PARG. In addition, phosphorylation of XRCC1 is also required for the proper dissociation kinetics of XRCC1 because (1) phosphorylation sites mutated in XRCC1 (X1 pm) cause retention of XRCC1 at sites of SSB for a longer time compared to wild type XRCC1; and (2) phosphorylation of XRCC1 is required for efficient polyubiquitylation of XRCC1. Interestingly, a mutant of XRCC1, LL360/361DD, which abolishes pAR binding, shows significant upregulation of ubiquitylation, indicating that pARylation of XRCC1 prevents the poly-ubiquitylation. We also found that the dynamics of the repair proteins DNA polymerase beta, PNK, APTX, PCNA and ligase I are regulated by domains of XRCC1. In summary, the dynamic damage response of XRCC1 is regulated in a manner that depends on modifications of polyADP-ribosylation, phosphorylation and ubiquitylation in live cells.
登录
查看更多内容
影响因子：
64.5
作者：
Loizou, JI;El-Khamisy, SF;Caldecott, KW
通讯作者：
Caldecott, KW
影响因子：
5.3
作者：
Fisher, Anna E. O.;Hochegger, Helfrid;Caldecott, Keith W.
通讯作者：
Caldecott, Keith W.
影响因子：
4.8
作者：
Della-Maria, Julie;Hegde, Muralidhar L.;Tomkinson, Alan E.
通讯作者：
Tomkinson, Alan E.
影响因子：
5.3
作者：
CALDECOTT, KW;MCKEOWN, CK;THOMPSON, LH
通讯作者：
THOMPSON, LH
影响因子：
14.9
作者：
El-Khamisy, SF;Masutani, M;Caldecott, KW
通讯作者：
Caldecott, KW