A crucial role for ATR in the regulation of deoxycytidine kinase activity
A crucial role for ATR in the regulation of deoxycytidine kinase activity
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DOI：
10.1016/j.bcp.2015.11.022
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发表时间：
2016-01-15
影响因子：
5.8
通讯作者：
Bontemps, Francoise
中科院分区：
文献类型：
--
作者：
Beyaert, Maxime;Starczewska, Eliza;Bontemps, Francoise
脱氧胞苷激酶（dCK）（EC 2.7.1.74）是用于挽救脱氧核苷和活化许多抗癌和抗病毒核苷类似物的关键酶。dCK活性在几种遗传毒性处理中增强，这与dCK在Ser-74的磷酸化增加相关。ATM最近被鉴定为负责电离辐射（IR）后Ser-74磷酸化和dCK激活的激酶。在这里，我们研究了ATM和相关激酶ATR在其他类型的DNA损伤诱导的dCK激活中的作用。使用ATM缺陷的细胞或ATM抑制剂KU-60019，我们发现ATM是不需要的dCK激活引起的紫外线，阿非迪霉素，克拉屈滨，出乎意料地也IR。另一方面，选择性ATR抑制剂VE-821显着减少上调dCK活性诱导这些遗传毒性剂，虽然不是IR，也下调基础dCK活性。通过使用ATR siRNA和ATR-Seckel细胞证实了ATR在控制dCK活性中的作用。ATR还被发现在体外直接磷酸化dCK的Ser-74。进一步的研究表明，ATR，这也是激活响应IR，虽然晚于ATM，是负责IR诱导的dCK激活ATM缺陷细胞或在KU-60019的存在下。总体而言，我们的研究结果表明，ATR控制基础dCK活性和dCK激活复制应激反应，并表明ATR可以激活dCK IR后，如果ATM是缺乏或抑制。(C)2015爱思唯尔公司All rights reserved.
Deoxycytidine kinase (dCK) (EC 2.7.1.74) is a key enzyme for salvage of deoxynucleosides and activation of numerous anticancer and antiviral nucleoside analogs. dCK activity is enhanced in response to several genotoxic treatments, which has been correlated with an increase of dCK phosphorylation at Ser-74. ATM was recently identified as the kinase responsible for Ser-74 phosphorylation and dCK activation after ionizing radiation (IR). Here, we investigated the role of ATM and the related kinase ATR in dCK activation induced by other types of DNA damage. Using ATM-deficient cells or the ATM inhibitor KU-60019, we found that ATM was not required for dCK activation caused by UV light, aphidicolin, cladribine, and unexpectedly also IR. On the other hand, the selective ATR inhibitor VE-821 significantly reduced up regulation of dCK activity induced by these genotoxic agents, though not IR, and also down-regulated basal dCK activity. A role for ATR in the control of dCK activity was confirmed by using ATR siRNA and ATR-Seckel cells. ATR was also found to directly phosphorylate dCK at Ser-74 in vitro. Further studies revealed that ATR, which is also activated in response to IR, although later than ATM, was responsible for IR-induced dCK activation in ATM-deficient cells or in the presence of KU-60019. Overall, our results demonstrate that ATR controls basal dCK activity and dCK activation in response to replication stress and indicate that ATR can activate dCK after IR if ATM is lacking or inhibited. (C) 2015 Elsevier Inc. All rights reserved.