Rad53 phosphorylation site clusters are important for Rad53 regulation and signaling
Rad53 phosphorylation site clusters are important for Rad53 regulation and signaling
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DOI：
10.1128/mcb.23.17.6300-6314.2003
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发表时间：
2003-09-01
影响因子：
5.3
通讯作者：
Stern, DF
中科院分区：
文献类型：
--
作者：
Lee, SJ;Schwartz, MF;Stern, DF
芽殖酵母Rad53是一种必需的蛋白激酶，其在响应DNA损伤时以MEC1和TEL1依赖性方式被磷酸化和激活。我们通过上游激酶Mec1和Tell的共有磷酸化位点的突变研究了Rad53磷酸化的作用。Rad53氨基末端TQ簇区域的丙氨酸取代降低了活力并损害了检查点功能。这些取代突变避免了与Asf1的基础相互作用和与Rad9的DNA损伤诱导的相互作用。然而，它们导致DNA损伤诱导的Rad53激酶活性降低，并与蛋白激酶Dun1的相互作用受损。Dun1 FHA（Forkhead相关）结构域在DNA损伤或复制阻断后识别Rad53的氨基末端TQ簇。因此，上游激酶对Rad53的磷酸化不仅对Rad53的激活很重要，而且对Rad53和Dun1之间界面的产生也很重要。
Budding yeast Rad53 is an essential protein kinase that is phosphorylated and activated in a MEC1- and TEL1-dependent manner in response to DNA damage. We studied the role of Rad53 phosphorylation through mutation of consensus phosphorylation sites for upstream kinases Mec1 and Tell. Alanine substitution of the Rad53 amino-terminal TQ cluster region reduced viability and impaired checkpoint functions. These substitution mutations spared the basal interaction with Asf1 and the DNA damage-induced interactions with Rad9. However, they caused a decrease in DNA damage-induced Rad53 kinase activity and an impaired interaction with the protein kinase Dun1. The Dun1 FHA (Forkhead-associated) domain recognized the amino-terminal TQ cluster of Rad53 after DNA damage or replication blockade. Thus, the phosphorylation of Rad53 by upstream kinases is important not only for Rad53 activation but also for creation of an interface between Rad53 and Dun1.