Kochenova Olga V, D'Alessandro Giuseppina, Pilger Domenic, Schmid Ernst, Richards Sean L, Garcia Marcos Rios, Jhujh Satpal S, Voigt Andrea, Gupta Vipul, Carnie Christopher J, Wu R Alex, Gueorguieva Nadia, Stewart Grant S, Walter Johannes C, Jackson Stephen P
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Blavatnik Institute; Boston, MA 02115, USA.
Howard Hughes Medical Institute; Boston, MA 02115, USA.
bioRxiv. 2024 Sep 4:2024.09.03.611025. doi: 10.1101/2024.09.03.611025.
The E3 ubiquitin ligase TRAIP associates with the replisome and helps this molecular machine deal with replication stress. Thus, TRAIP promotes DNA inter-strand crosslink repair by triggering the disassembly of CDC45-MCM2-7-GINS (CMG) helicases that have converged on these lesions. However, disassembly of single CMGs that have stalled temporarily would be deleterious, suggesting that TRAIP must be carefully regulated. Here, we demonstrate that human cells lacking the de-ubiquitylating enzyme USP37 are hypersensitive to topoisomerase poisons and other replication stress-inducing agents. We further show that TRAIP loss rescues the hypersensitivity of knockout cells to topoisomerase inhibitors. In egg extracts depleted of USP37, TRAIP promotes premature CMG ubiquitylation and disassembly when converging replisomes stall. Finally, guided by AlphaFold-Multimer, we discovered that binding to CDC45 mediates USP37's response to topological stress. In conclusion, we propose that USP37 protects genome stability by preventing TRAIP-dependent CMG unloading when replication stress impedes timely termination.
E3泛素连接酶TRAIP与复制体相关联，并帮助这一分子机器应对复制压力。因此，TRAIP通过触发聚集在这些损伤部位的CDC45-MCM2-7-GINS（CMG）解旋酶的解体来促进DNA链间交联修复。然而，暂时停滞的单个CMG的解体会是有害的，这表明TRAIP必须受到严格调控。在此，我们证明，缺乏去泛素化酶USP37的人类细胞对拓扑异构酶毒物和其他复制应激诱导剂高度敏感。我们进一步表明，TRAIP的缺失挽救了基因敲除细胞对拓扑异构酶抑制剂的超敏感性。在缺乏USP37的卵提取物中，当聚集的复制体停滞时，TRAIP会促进CMG过早泛素化和解体。最后，在AlphaFold-Multimer的指导下，我们发现与CDC45的结合介导了USP37对拓扑应激的反应。总之，我们提出，当复制压力阻碍及时终止时，USP37通过防止TRAIP依赖的CMG卸载来保护基因组稳定性。
