A forward chemical genetic screen reveals an inhibitor of the Mre11-Rad50-Nbs1 complex

作者：Dupre Aude; Boyer Chatenet Louise; Sattler Rose M; Modi Ami P; Lee Ji Hoon; Nicolette Matthew L; Kopelovich Levy; Jasin Maria; Baer Richard; Paull Tanya T; Gautier Jean^*

来源：Nature Chemical Biology, 2008, 4(2): 119-125.

DOI：10.1038/nchembio.63

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.

• 出版日期2008-2