Projects per year
Abstract
The eukaryotic replisome assembles around the CMG helicase, which stably associates with DNA replication forks throughout elongation. When replication terminates, CMG is ubiquitylated on its Mcm7 subunit and disassembled by the Cdc48/p97 ATPase. Until now, the regulation that restricts CMG ubiquitylation to termination was unknown, as was the mechanism of disassembly. By reconstituting these processes with purified budding yeast proteins, we show that ubiquitylation is tightly repressed throughout elongation by the Y-shaped DNA structure of replication forks. Termination removes the repressive DNA structure, whereupon long K48-linked ubiquitin chains are conjugated to CMG-Mcm7, dependent on multiple replisome components that bind to the ubiquitin ligase SCF Dia2. This mechanism pushes CMG beyond a ‘5-ubiquitin threshold’ that is inherent to Cdc48, which specifically unfolds ubiquitylated Mcm7 and thereby disassembles CMG. These findings explain the exquisite regulation of CMG disassembly and provide a general model for the disassembly of ubiquitylated protein complexes by Cdc48.
Original language | English |
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Article number | e60371 |
Number of pages | 33 |
Journal | eLife |
Volume | 9 |
DOIs | |
Publication status | Published - 17 Aug 2020 |
Keywords
- CMG helicase
- eukaryotic replisome
- SCFDia2
- ubiquitylation
- Cdc48 / p97
- DNA replication fork
- chromosome duplication
- Ctf4
- Mrc1
- Pol ɛ
ASJC Scopus subject areas
- General Immunology and Microbiology
- General Biochemistry,Genetics and Molecular Biology
- General Neuroscience
Fingerprint
Dive into the research topics of 'CMG helicase disassembly is controlled by replication fork DNA, replisome components and a ubiquitin threshold'. Together they form a unique fingerprint.Projects
- 3 Finished
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Novel Genome Integrity Pathways that Regulate DNA Replication Termination in Metazoa
Labib, K. (Investigator)
1/03/18 → 1/09/23
Project: Research
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Molecular Mechanisms of DNA Replication Termination
Deegan, T. (Investigator)
1/05/17 → 1/11/21
Project: Research
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Functional Dissection of the Eukaryotic Replisome (Senior Investigator Award)
Labib, K. (Investigator)
1/04/14 → 29/02/20
Project: Research