Mitotic CDK Promotes Replisome Disassembly, Fork Breakage, and Complex DNA Rearrangements

Mol Cell. 2019 Mar 7;73(5):915-929.e6. doi: 10.1016/j.molcel.2018.12.021.


DNA replication errors generate complex chromosomal rearrangements and thereby contribute to tumorigenesis and other human diseases. One mechanism that triggers these errors is mitotic entry before the completion of DNA replication. To address how mitosis might affect DNA replication, we used Xenopus egg extracts. When mitotic CDK (Cyclin B1-CDK1) is used to drive interphase egg extracts into a mitotic state, the replicative CMG (CDC45/MCM2-7/GINS) helicase undergoes ubiquitylation on its MCM7 subunit, dependent on the E3 ubiquitin ligase TRAIP. Whether replisomes have stalled or undergone termination, CMG ubiquitylation is followed by its extraction from chromatin by the CDC48/p97 ATPase. TRAIP-dependent CMG unloading during mitosis is also seen in C. elegans early embryos. At stalled forks, CMG removal results in fork breakage and end joining events involving deletions and templated insertions. Our results identify a mitotic pathway of global replisome disassembly that can trigger replication fork collapse and DNA rearrangements.

Keywords: CMG; DNA replication; TRAIP; fork collapse; genome rearrangement; premature mitotic entry; replication stress; template switching.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism
  • Animals
  • Caenorhabditis elegans / genetics
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans Proteins / genetics
  • Caenorhabditis elegans Proteins / metabolism
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • Cyclin B1 / genetics
  • Cyclin B1 / metabolism*
  • DNA / biosynthesis*
  • DNA / genetics
  • DNA Damage*
  • DNA Repair
  • DNA Replication*
  • DNA-Directed DNA Polymerase / genetics
  • DNA-Directed DNA Polymerase / metabolism
  • Gene Rearrangement*
  • Minichromosome Maintenance Proteins / genetics
  • Minichromosome Maintenance Proteins / metabolism
  • Mitosis*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism
  • Protein Kinases / genetics
  • Protein Kinases / metabolism*
  • Protein Serine-Threonine Kinases / genetics
  • Protein Serine-Threonine Kinases / metabolism
  • Ubiquitin-Protein Ligases / genetics
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination
  • Xenopus Proteins / genetics
  • Xenopus Proteins / metabolism*
  • Xenopus laevis / genetics
  • Xenopus laevis / metabolism


  • Caenorhabditis elegans Proteins
  • Cdc45 protein, Xenopus
  • Cell Cycle Proteins
  • Cyclin B1
  • Nuclear Proteins
  • Xenopus Proteins
  • DNA
  • Ubiquitin-Protein Ligases
  • Protein Kinases
  • CDK1 protein, Xenopus
  • AURKA protein, Xenopus
  • Plk1 protein, Xenopus
  • Protein Serine-Threonine Kinases
  • DNA polymerase theta
  • DNA-Directed DNA Polymerase
  • Adenosine Triphosphatases
  • p97 ATPase
  • Minichromosome Maintenance Proteins