Direct kinase-to-kinase signaling mediated by the FHA phosphoprotein recognition domain of the Dun1 DNA damage checkpoint kinase
Direct kinase-to-kinase signaling mediated by the FHA phosphoprotein recognition domain of the Dun1 DNA damage checkpoint kinase
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DOI：
10.1128/mcb.23.4.1441-1452.2003
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发表时间：
2003-02-01
影响因子：
5.3
通讯作者：
Heyer, WD
中科院分区：
文献类型：
--
作者：
Bashkirov, VI;Bashkirova, EV;Heyer, WD
丝氨酸-苏氨酸激酶 Dun1 含有叉头相关 (FRA) 结构域，在酿酒酵母的 DNA 损伤检查点通路中发挥作用。它属于检查点激酶 Chk2 家族，该家族包括酿酒酵母 Rad53 和 Mek1、粟酒裂殖酵母 Cds1 和人类 Chk2。 Dun1 是 DNA 损伤诱导的某些靶基因转录、DNA 损伤后短暂的 G(2)/M 停滞以及 DNA 损伤诱导的 DNA 修复蛋白 Rad55 磷酸化所必需的。在这里，我们报道了 Dun1 的 FRA 磷蛋白识别结构域是 Rad53 激酶在体外和体内直接磷酸化 Dun1 所必需的。 Rad53 的反式磷酸化不需要 Dun1 激酶活性，并且可能仅涉及两种激酶之间的短暂相互作用。 Dun1 激酶在 DNA 损伤诱导的转录、G(2)/M 细胞周期停滞和 Rad55 磷酸化中的检查点功能在 Dun1 的 FRA 结构域突变体中受到严重损害。因此，Dun1 FRA 结构域突变体对紫外线、甲磺酸甲酯和复制抑制剂羟基脲诱导的基因毒性应激表现出增强的敏感性。我们发现 Dun1 FRA 结构域对于 DNA 损伤检查点通路中从 Rad53 到 Dun1 的直接激酶到激酶信号转导至关重要。
The serine-threonine kinase Dun1 contains a forkhead-associated (FRA) domain and functions in the DNA damage checkpoint pathway of Saccharomyces cerevisiae. It belongs to the Chk2 family of checkpoint kinases, which includes S. cerevisiae Rad53 and Mek1, Schizosaccharomyces pombe Cds1, and human Chk2. Dun1 is required for DNA damage-induced transcription of certain target genes, transient G(2)/M arrest after DNA damage, and DNA damage-induced phosphorylation of the DNA repair protein Rad55. Here we report that the FRA phosphoprotein recognition domain of Dun1 is required for direct phosphorylation of Dun1 by Rad53 kinase in vitro and in vivo. trans phosphorylation by Rad53 does not require the Dun1 kinase activity and is likely to involve only a transient interaction between the two kinases. The checkpoint functions of Dun1 kinase in DNA damage-induced transcription, G(2)/M cell cycle arrest, and Rad55 phosphorylation are severely compromised in an FRA domain mutant of Dun1. As a consequence, the Dun1 FRA domain mutant displays enhanced sensitivity to genotoxic stress induced by UV, methyl methanesulfonate, and the replication inhibitor hydroxyurea. We show that the Dun1 FRA domain is critical for direct kinase-to-kinase signaling from Rad53 to Dun1 in the DNA damage checkpoint pathway.