ATM phosphorylates PP2A subunit A resulting in nuclear export and spatiotemporal regulation of the DNA damage response.
ATM phosphorylates PP2A subunit A resulting in nuclear export and spatiotemporal regulation of the DNA damage response.
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DOI：
10.1007/s00018-022-04550-5
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发表时间：
2022-11-24
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影响因子：
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共济失调毛细血管扩张症突变（ATM）是一种丝氨酸-苏氨酸蛋白激酶，是DNA损伤反应（DDR）的重要调节因子。一个关键的ATM靶标是蛋白磷酸酶2A（PP 2A）的结构亚基A（PR 65-S401），已知其调节多种细胞过程，例如有丝分裂和细胞生长，以及在从DDR恢复期间使许多蛋白质去磷酸化。我们产生了表达PR 65-WT、-S401 A（不能磷酸化）和-S401 D（磷酸模拟）转基因的小鼠胚胎成纤维细胞。值得注意的是，S401突变体表现出广泛的染色体畸变，受损的DNA双链断裂（DSB）修复和有丝分裂灾难增加辐射后。S401 A和S401 D细胞均表现出受损的DSB修复（非同源末端连接和同源重组修复），并表现出延迟的DNA损伤恢复，这反映在辐射存活率降低。此外，S401 D细胞显示出增加的ERK和AKT信号传导，导致生长速率增加，进一步强调了ATM-PP 2A信号传导在调节促存活反应中发挥的多种作用。延时视频和细胞定位实验表明，PR 65输出到细胞质辐射后的CRM 1，核输出蛋白，在非常快速的多效性效应观察。一个假定的核输出序列（内斯）接近S401被确定，当突变导致异常PR 65穿梭。我们的研究表明，一个单一的，关键的PR 65氨基酸（S401）的磷酸化ATM从根本上控制DDR，并平衡DSB修复质量，细胞存活和生长的时空PR 65核质穿梭核输出受体CRM 1介导的。在线版本包含补充材料，可通过10.1007/s 00018 -022-04550-5获得。
Ataxia telangiectasia mutated (ATM) is a serine–threonine protein kinase and important regulator of the DNA damage response (DDR). One critical ATM target is the structural subunit A (PR65–S401) of protein phosphatase 2A (PP2A), known to regulate diverse cellular processes such as mitosis and cell growth as well as dephosphorylating many proteins during the recovery from the DDR. We generated mouse embryonic fibroblasts expressing PR65-WT, -S401A (cannot be phosphorylated), and -S401D (phospho-mimetic) transgenes. Significantly, S401 mutants exhibited extensive chromosomal aberrations, impaired DNA double-strand break (DSB) repair and underwent increased mitotic catastrophe after radiation. Both S401A and the S401D cells showed impaired DSB repair (nonhomologous end joining and homologous recombination repair) and exhibited delayed DNA damage recovery, which was reflected in reduced radiation survival. Furthermore, S401D cells displayed increased ERK and AKT signaling resulting in enhanced growth rate further underscoring the multiple roles ATM–PP2A signaling plays in regulating prosurvival responses. Time-lapse video and cellular localization experiments showed that PR65 was exported to the cytoplasm after radiation by CRM1, a nuclear export protein, in line with the very rapid pleiotropic effects observed. A putative nuclear export sequence (NES) close to S401 was identified and when mutated resulted in aberrant PR65 shuttling. Our study demonstrates that the phosphorylation of a single, critical PR65 amino acid (S401) by ATM fundamentally controls the DDR, and balances DSB repair quality, cell survival and growth by spatiotemporal PR65 nuclear–cytoplasmic shuttling mediated by the nuclear export receptor CRM1. The online version contains supplementary material available at 10.1007/s00018-022-04550-5.
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影响因子：
19
作者：
Ceccaldi R;Rondinelli B;D'Andrea AD
通讯作者：
D'Andrea AD
影响因子：
64.5
作者：
Fornerod, M;Ohno, M;Mattaj, IW
通讯作者：
Mattaj, IW
DOI：
10.1073/pnas.0804608105
发表时间：
2008-11-04
影响因子：
11.1
作者：
Cai, Xin;Liu, Xuan
通讯作者：
Liu, Xuan
影响因子：
4.8
作者：
Favre, B;Turowski, P;Hemmings, BA
通讯作者：
Hemmings, BA
DOI：
10.1073/pnas.0709879104
发表时间：
2007-12-11
影响因子：
11.1
作者：
Forester, Craig M.;Maddox, Jessica;Virshup, David M.
通讯作者：
Virshup, David M.