1. Academic Validation
  2. Mitotic entry drives replisome disassembly at stalled replication forks

Mitotic entry drives replisome disassembly at stalled replication forks

  • Biochem Biophys Res Commun. 2018 Nov 17;506(1):108-113. doi: 10.1016/j.bbrc.2018.10.064.
Yoshitami Hashimoto 1 Hirofumi Tanaka 2
Affiliations

Affiliations

  • 1 School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan. Electronic address: hashimo@toyaku.ac.jp.
  • 2 School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan.
Abstract

The disassembly of eukaryotic replisome during replication termination is mediated by CRL-dependent poly-ubiquitylation of Mcm7 and p97 segregase. The replisome also disassembles at stalled or collapsed replication forks under certain stress conditions, but the underlying mechanism is poorly understood. Here, we discovered a novel pathway driving stepwise disassembly of the replisome at stalled replication forks after forced entry into M-phase using Xenopus egg extracts. This pathway was dependent on M-CDK activity and K48- and K63-linked poly-ubiquitylation but not on CRL and p97, which is different from known pathways. Furthermore, this pathway could not disassemble converged replisomes whose Mcm7 subunit had been poly-ubiquitylated without p97. These results suggest that there is a distinctive pathway for replisome disassembly when stalled replication forks persist into M-phase.

Keywords

CDK; CMG complex; Replisome; Ubiquitylation; Xenopus egg extract; p97/VCP/Cdc48.

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