DDK Phosphorylates Checkpoint Clamp Component Rad9 and Promotes Its Release from Damaged Chromatin
DDK Phosphorylates Checkpoint Clamp Component Rad9 and Promotes Its Release from Damaged Chromatin
复制标题
DOI：
10.1016/j.molcel.2010.10.026
复制
发表时间：
2010-11-24
期刊：
影响因子：
16
通讯作者：
Carr, Antony M.
中科院分区：
文献类型：
--
作者：
Furuya, Kanji;Miyabe, Izumi;Carr, Antony M.
当不合适的DNA结构出现时，它们被DNA结构依赖的检查点通路感知并随后修复。检查点蛋白在这些结构上的募集先于参与DNA代谢的蛋白的募集。因此，检查点可以调节DNA代谢。我们发现，分裂酵母Rad9是一种9-1-1异三聚体的checkpoint-clamp成分，在复制诱导的DNA损伤中，分裂糖酵母pombe db4依赖性激酶（DDK）同源物Hsk1（Cdc7）磷酸化。Rad9的磷酸化破坏了它与复制蛋白A （RPA）的相互作用，并依赖于9-1-1染色质负载、Rad9相关蛋白Rad4/Cut5（TopBP1）和Rad3的先前磷酸化（ATR）。DDK磷酸化缺陷的rad9突变体在复制应激后表现出野生型检查点反应，但DNA修复蛋白位点异常，生存能力下降。我们认为，DDK对Rad9的磷酸化可以将Rad9从DNA损伤位点释放出来，从而促进DNA修复。
When inappropriate DNA structures arise, they are sensed by DNA structure-dependent checkpoint pathways and subsequently repaired. Recruitment of checkpoint proteins to such structures precedes recruitment of proteins involved in DNA metabolism. Thus, checkpoints can regulate DNA metabolism. We show that fission yeast Rad9, a 9-1-1 heterotrimeric checkpoint-clamp component, is phosphorylated by Hsk1(Cdc7), the Schizosaccharomyces pombe Dbf4-dependent kinase (DDK) homolog, in response to replication-induced DNA damage. Phosphorylation of Rad9 disrupts its interaction with replication protein A (RPA) and is dependent on 9-1-1 chromatin loading, the Rad9-associated protein Rad4/Cut5(TopBP1), and prior phosphorylation by Rad3(ATR). rad9 mutants defective in DDK phosphorylation show wild-type checkpoint responses but abnormal DNA repair protein foci and decreased viability after replication stress. We propose that Rad9 phosphorylation by DDK releases Rad9 from DNA damage sites to facilitate DNA repair.