Requirement of the FATC domain of protein kinase Tel1 for localization to DNA ends and target protein recognition.
Requirement of the FATC domain of protein kinase Tel1 for localization to DNA ends and target protein recognition.
复制标题
需要蛋白激酶 Tel1 的 FATC 结构域定位到 DNA 末端并识别目标蛋白。
DOI：
10.1091/mbc.e15-05-0259
复制
发表时间：
2015-10-01
影响因子：
3.3
通讯作者：
Sugimoto K
中科院分区：
文献类型：
--
作者：
Ogi H;Goto GH;Ghosh A;Zencir S;Henry E;Sugimoto K
The FATC domain of Tel1 is studied via introduction of substitution and truncation mutations. It is found to be required for localization to sites of DNA damage and is essential for phosphorylation of exogenous substrates but dispensable for the intrinsic kinase activity. Two large phosphatidylinositol 3-kinase–related protein kinases (PIKKs), ATM and ATR, play a central role in the DNA damage response pathway. PIKKs contain a highly conserved extreme C-terminus called the FRAP-ATM-TRRAP-C-terminal (FATC) domain. In budding yeast, ATM and ATR correspond to Tel1 and Mec1, respectively. In this study, we characterized functions of the FATC domain of Tel1 by introducing substitution or truncation mutations. One substitution mutation, termed tel1-21, and a truncation mutation, called tel1-ΔC, did not significantly affect the expression level. The tel1-21 mutation impaired the cellular response to DNA damage and conferred moderate telomere maintenance defect. In contrast, the tel1-ΔC mutation behaved like a null mutation, conferring defects in both DNA damage response and telomere maintenance. Tel1-21 protein localized to DNA ends as effectively as wild-type Tel1 protein, whereas Tel1-ΔC protein failed. Introduction of a hyperactive TEL1-hy mutation suppressed the tel1-21 mutation but not the tel1-ΔC mutation. In vitro analyses revealed that both Tel1-21 and Tel1-ΔC proteins undergo efficient autophosphorylation but exhibit decreased kinase activities toward the exogenous substrate protein, Rad53. Our results show that the FATC domain of Tel1 mediates localization to DNA ends and contributes to phosphorylation of target proteins.
