Long-range DNA end resection supports homologous recombination by checkpoint activation rather than extensive homology generation

  1. Michael T Kimble
  2. Matthew J Johnson
  3. Mattie R Nester
  4. Lorraine S Symington  Is a corresponding author
  1. Columbia University Medical Center, United States

Abstract

Homologous recombination (HR), the high-fidelity mechanism for double-strand break (DSB) repair, relies on DNA end resection by nucleolytic degradation of the 5¢-terminated ends. However, the role of long-range resection mediated by Exo1 and/or Sgs1-Dna2 in HR is not fully understood. Here, we show that Exo1 and Sgs1 are dispensable for recombination between closely-linked repeats, but are required for interchromosomal repeat recombination in Saccharomyces cerevisiae. This context-specific requirement for long-range end resection is connected to its role in activating the DNA damage checkpoint. Consistent with this role, checkpoint mutants also show a defect specifically in interchromosomal recombination. Furthermore, artificial activation of the checkpoint partially restores interchromosomal recombination to exo1∆ sgs1∆ cells. However, cell cycle delay is insufficient to rescue the interchromosomal recombination defect of exo1∆ sgs1∆ cells, suggesting an additional role for the checkpoint. Given that the checkpoint is necessary for DNA damage-induced chromosome mobility, we propose that the importance of the checkpoint, and therefore long-range resection, in interchromosomal recombination is due to a need to increase chromosome mobility to facilitate pairing of distant sites. The need for long-range resection is circumvented when the DSB and its repair template are in close proximity.

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All data generated or analyzed during this study are included in the manuscript and supporting files; Source data files have been provided for Figures 1-5 and Supplementary Figures 1-6

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Author details

  1. Michael T Kimble

    Department of Microbiology and Immunology, Columbia University Medical Center, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Matthew J Johnson

    Department of Microbiology and Immunology, Columbia University Medical Center, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Mattie R Nester

    Department of Microbiology and Immunology, Columbia University Medical Center, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Lorraine S Symington

    Department of Microbiology and Immunology, Columbia University Medical Center, New York, United States
    For correspondence
    lss5@cumc.columbia.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1519-4800

Funding

National Institute of General Medical Sciences (R35 GM126997)

  • Michael T Kimble
  • Matthew J Johnson
  • Mattie R Nester
  • Lorraine S Symington

National Institute of General Medical Sciences (T32 GM008798)

  • Michael T Kimble

NIH/NCI (T32 CA265828)

  • Matthew J Johnson

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Copyright

© 2023, Kimble et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

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https://doi.org/10.7554/eLife.84322

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