A forward chemical genetic screen reveals an inhibitor of the Mre11-Rad50-Nbs1 complex
A forward chemical genetic screen reveals an inhibitor of the Mre11-Rad50-Nbs1 complex
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DOI：
10.1038/nchembio.63
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发表时间：
2008-02-01
影响因子：
14.8
通讯作者：
Gautier, Jean
中科院分区：
文献类型：
--
作者：
Dupre, Aude;Boyer-Chatenet, Louise;Gautier, Jean
MRN（Mre 11-Rad 50-Nbs 1）-ATM（共济失调-毛细血管扩张突变）通路对于DNA双链断裂的传感和信号传导至关重要。MRN复合物作为DNA损伤传感器，在DNA复制期间维持基因组稳定性，促进同源依赖性DNA修复并激活ATM。MRN对于细胞活力是必不可少的，这限制了复合物的功能研究。MRN的小分子抑制剂可以规避这种实验限制，也可以用作细胞的放射和化疗增敏化合物。使用无细胞系统，忠实地概括了MRN-ATM信号通路，我们设计了一个正向化学遗传筛选，以确定该途径的抑制剂，我们分离6-（4-羟基苯基）-2-硫代-2，3-二氢-4（1H）-嘧啶酮（mirin，1）作为MRN的抑制剂。Mirin阻止ATM的MRN依赖性活化，而不影响ATM蛋白激酶活性，并抑制Mre 11相关的核酸外切酶活性。与其靶向MRN复合物的能力一致，mirin消除了哺乳动物细胞中的G2/M检查点和同源依赖性修复。
The MRN (Mre11-Rad50-Nbs1)-ATM (ataxia-telangiectasia mutated) pathway is essential for sensing and signaling from DNA double-strand breaks. The MRN complex acts as a DNA damage sensor, maintains genome stability during DNA replication, promotes homology-dependent DNA repair and activates ATM. MRN is essential for cell viability, which has limited functional studies of the complex. Small-molecule inhibitors of MRN could circumvent this experimental limitation and could also be used as cellular radio- and chemosensitization compounds. Using cell-free systems that recapitulate faithfully the MRN-ATM signaling pathway, we designed a forward chemical genetic screen to identify inhibitors of the pathway, and we isolated 6-(4-hydroxyphenyl)-2-thioxo-2,3-dihydro-4(1H)-pyrimidinone (mirin, 1) as an inhibitor of MRN. Mirin prevents MRN-dependent activation of ATM without affecting ATM protein kinase activity, and it inhibits Mre11-associated exonuclease activity. Consistent with its ability to target the MRN complex, mirin abolishes the G2/M checkpoint and homology-dependent repair in mammalian cells.