Bolhuis Derek L, Fleifel Dalia, Bonacci Thomas, Wang Xianxi, Mouery Brandon L, Cook Jeanette Gowen, Brown Nicholas G, Emanuele Michael J
Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, North Carolina 27599, USA.
Department of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA.
bioRxiv. 2024 Sep 3:2024.09.03.610997. doi: 10.1101/2024.09.03.610997.
The CMG helicase (CDC45-MCM2-7-GINS) unwinds DNA as a component of eukaryotic replisomes. Replisome (dis)assembly is tightly coordinated with cell cycle progression to ensure genome stability. However, factors that prevent premature CMG unloading and replisome disassembly are poorly described. Since disassembly is catalyzed by ubiquitination, deubiquitinases (DUBs) represent attractive candidates for safeguarding against untimely and deleterious CMG unloading. We combined a targeted loss-of-function screen with quantitative, single-cell analysis to identify human USP37 as a key DUB preventing replisome disassembly. We demonstrate that USP37 maintains active replisomes on S-phase chromatin and promotes normal cell cycle progression. Proteomics and enzyme assays revealed USP37 interacts with the CMG complex to deubiquitinate MCM7, thus antagonizing replisome disassembly. Significantly, USP37 protects normal epithelial cells from oncoprotein-induced replication stress. Our findings reveal USP37 to be critical to the maintenance of replisomes in S-phase and suggest USP37-targeting as a potential strategy for treating malignancies with defective DNA replication control.
CMG解旋酶（CDC45-MCM2-7-GINS）作为真核生物复制体的一个组成部分解开DNA。复制体的组装和解组装与细胞周期进程紧密协调，以确保基因组稳定性。然而，防止CMG过早卸载和复制体解组装的因素却鲜有描述。由于解组装是由泛素化催化的，去泛素化酶（DUBs）成为防止CMG过早卸载和有害解组装的有吸引力的候选者。我们将靶向功能丧失筛选与定量单细胞分析相结合，以确定人类USP37是防止复制体解组装的关键DUB。我们证明USP37在S期染色质上维持活跃的复制体，并促进正常的细胞周期进程。蛋白质组学和酶分析表明，USP37与CMG复合物相互作用，使MCM7去泛素化，从而拮抗复制体的解组装。重要的是，USP37保护正常上皮细胞免受癌蛋白诱导 的复制应激。我们的研究结果表明USP37对维持S期复制体至关重要，并表明靶向USP37是治疗DNA复制控制缺陷的恶性肿瘤的潜在策略。
