ATR Kinase Activity Limits Mutagenesis and Promotes the Clonogenic Survival of Quiescent Human Keratinocytes Exposed to UVB Radiation.
ATR Kinase Activity Limits Mutagenesis and Promotes the Clonogenic Survival of Quiescent Human Keratinocytes Exposed to UVB Radiation.
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ATR 激酶活性限制突变并促进暴露于 UVB 辐射的静态人类角质形成细胞的克隆存活。
DOI：
10.1111/php.13164
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发表时间：
2020
影响因子：
3.3
通讯作者：
Kemp,MichaelG
中科院分区：
文献类型：
--
作者：
Shaj,Kavya;Hutcherson,RebekahJ;Kemp,MichaelG
ATR蛋白激酶在细胞周期的DNA合成阶段维持基因组完整性方面具有良好的作用。然而，ATR在不活跃复制DNA的细胞中的功能仍然在很大程度上未被探索。使用HaCaT和端粒酶-永生化的人角质形成细胞在体外保持融合，非复制状态，ATR被发现在UVB辐射下以依赖于核苷酸切除修复因子和DNA移位酶XPB的方式被强烈激活。在这些条件下抑制ATR激酶活性会对急性细胞存活和细胞毒性产生负面影响，并严重抑制UVB照射的HaCaT角质形成细胞在生长因子刺激下增殖的能力。此外，ATR激酶抑制在静止的HaCaT角质形成细胞增强UVB诱变的次黄嘌呤磷酸核糖转移酶基因座。尽管ATR抑制不影响环丁烷嘧啶二聚体从基因组DNA中去除的速率，但PCNA单泛素化和染色质相关的PCNA和RPA水平升高表明，在缺乏ATR信号传导的情况下，切除间隙填充合成发生了改变。这些结果表明ATR激酶在防止诱变和促进暴露于UVB辐射的静止角质形成细胞的增殖潜力中起重要作用。
The ATR protein kinase has well‐described roles in maintaining genomic integrity during the DNA synthesis phase of the cell cycle. However, ATR function in cells that are not actively replicating DNA remains largely unexplored. Using HaCaT and telomerase‐immortalized human keratinocytes maintained in a confluent, nonreplicating state in vitro, ATR was found to be robustly activated in response to UVB radiation in a manner dependent on the nucleotide excision repair factor and DNA translocase XPB. Inhibition of ATR kinase activity under these conditions negatively impacted acute cell survival and cytotoxicity and severely inhibited the ability of UVB‐irradiated HaCaT keratinocytes to proliferate upon stimulation with growth factors. Furthermore, ATR kinase inhibition in quiescent HaCaT keratinocytes potentiated UVB mutagenesis at the hypoxanthine phosphoribosyltransferase locus. Though ATR inhibition did not impact the rate of removal of cyclobutane pyrimidine dimers from genomic DNA, elevated levels of PCNA mono‐ubiquitination and chromatin‐associated PCNA and RPA indicate that excision gap‐filling synthesis was altered in the absence of ATR signaling. These results indicate that the ATR kinase plays important roles in preventing mutagenesis and in promoting the proliferative potential of quiescent keratinocytes exposed to UVB radiation.