ATR and ATM differently regulate WRN to prevent DSBs at stalled replication forks and promote replication fork recovery
ATR and ATM differently regulate WRN to prevent DSBs at stalled replication forks and promote replication fork recovery
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DOI：
10.1038/emboj.2010.205
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发表时间：
2010-09-15
期刊：
影响因子：
11.4
通讯作者：
Pichierri, Pietro
中科院分区：
文献类型：
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作者：
Ammazzalorso, Francesca;Pirzio, Livia Maria;Pichierri, Pietro
对复制阻滞的准确反应是保持基因组稳定的关键，需要ATR和ATM功能。Werner综合征蛋白（WRN）与停滞的复制分叉的恢复有关，尽管在复制停止后观察到ATR/ atm依赖的WRN磷酸化，但这种修饰在响应受干扰的复制过程中的功能尚不清楚。在这里，我们报道了ATR在多个c端S/TQ残基上直接磷酸化WRN。atr介导的WRN磷酸化抑制了WRN在核灶中的适当积累，与RPA共定位，并导致停滞分叉的断裂。另一方面，抑制ATM激酶活性或ATM不磷酸化的WRN等位基因的表达会导致WRN在核灶中保留，RAD51重组酶的募集受损，导致分叉塌陷后的生存能力降低。总之，我们的研究结果表明，ATR和ATM通过在对复制分叉停止的响应的定义时刻不同地调节WRN来促进从受干扰的复制中恢复。
Accurate response to replication arrest is crucial to preserve genome stability and requires both the ATR and ATM functions. The Werner syndrome protein (WRN) is implicated in the recovery of stalled replication forks, and although an ATR/ATM-dependent phosphorylation of WRN was observed after replication arrest, the function of such modifications during the response to perturbed replication is not yet appreciated. Here, we report that WRN is directly phosphorylated by ATR at multiple C-terminal S/TQ residues. Suppression of ATR-mediated phosphorylation of WRN prevents proper accumulation of WRN in nuclear foci, co-localisation with RPA and causes breakage of stalled forks. On the other hand, inhibition of ATM kinase activity or expression of an ATM-unphosphorylable WRN allele leads to retention of WRN in nuclear foci and impaired recruitment of RAD51 recombinase resulting in reduced viability after fork collapse. Altogether, our findings indicate that ATR and ATM promote recovery from perturbed replication by differently regulating WRN at defined moments of the response to replication fork arrest.