BRCA2 BRC missense variants disrupt RAD51-dependent DNA repair

  1. Judit Jimenez-Sainz
  2. Joshua Mathew
  3. Gemma Moore
  4. Sudipta Lahiri
  5. Jennifer Garbarino
  6. Joseph P Eder
  7. Eli Rothenberg
  8. Ryan B Jensen  Is a corresponding author
  1. Yale University, United States
  2. New York University, United States

Abstract

Pathogenic mutations in the BRCA2 tumor suppressor gene predispose to breast, ovarian, pancreatic, prostate, and other cancers. BRCA2 maintains genome stability through homology-directed repair (HDR) of DNA double-strand breaks (DSBs) and replication fork protection. Nonsense or frameshift mutations leading to truncation of the BRCA2 protein are typically considered pathogenic, however, missense mutations resulting in single amino acid substitutions can be challenging to functionally interpret. The majority of missense mutations in BRCA2 have been classified as Variants of Uncertain Significance (VUS) with unknown functional consequences. In this study, we identified three BRCA2 VUS located within the BRC repeat region to determine their impact on canonical HDR and fork protection functions. We provide evidence that S1221P and T1980I, which map to conserved residues in the BRC2 and BRC7 repeats, compromise the cellular response to chemotherapeutics and ionizing radiation, and display deficits in fork protection. We further demonstrate biochemically that S1221P and T1980I disrupt RAD51 binding and diminish the ability of BRCA2 to stabilize RAD51-ssDNA complexes. The third variant, T1346I, located within the spacer region between BRC2 and BRC3 repeats, is fully functional. We conclude that T1346I is a benign allele whereas S1221P and T1980I are hypomorphic disrupting the ability of BRCA2 to fully engage and stabilize RAD51 nucleoprotein filaments. Our results underscore the importance of correctly classifying BRCA2 VUS as pathogenic variants can impact both future cancer risk and guide therapy selection during cancer treatment.

Data availability

All data generated or analyzed during this study are included in the manuscript and supporting files.

Article and author information

Author details

  1. Judit Jimenez-Sainz

    Department of Therapeutic Radiology, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1048-8623
  2. Joshua Mathew

    Department of Therapeutic Radiology, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-5743-2670
  3. Gemma Moore

    Department of Therapeutic Radiology, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2656-0538
  4. Sudipta Lahiri

    Department of Therapeutic Radiology, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Jennifer Garbarino

    Department of Therapeutic Radiology, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Joseph P Eder

    Department of Medical Oncology, Yale University, New Haven, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Eli Rothenberg

    Department of Biochemistry and Molecular Pharmacology, New York University, New York, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-1382-1380
  8. Ryan B Jensen

    Department of Therapeutic Radiology, Yale University, New Haven, United States
    For correspondence
    ryan.jensen@yale.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9844-0789

Funding

National Cancer Institute (CA215990)

  • Ryan B Jensen

Chavkin Philanthropic

  • Eli Rothenberg

Women's Health Research at Yale

  • Ryan B Jensen

The Gray Foundation

  • Ryan B Jensen

Lion Heart Pilot Grant

  • Judit Jimenez-Sainz

National Institutes of Health (R35 GM134947)

  • Eli Rothenberg

National Institutes of Health (AI153040)

  • Eli Rothenberg

National Institutes of Health (CA247773)

  • Eli Rothenberg

The V Foundation BRCA Research

  • Eli Rothenberg

Pfizer

  • Eli Rothenberg

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

Reviewing Editor

  1. Andrés Aguilera, CABIMER, Universidad de Sevilla, Spain

Publication history

  1. Preprint posted: September 25, 2021 (view preprint)
  2. Received: April 1, 2022
  3. Accepted: September 12, 2022
  4. Accepted Manuscript published: September 13, 2022 (version 1)
  5. Accepted Manuscript updated: September 14, 2022 (version 2)
  6. Version of Record published: October 7, 2022 (version 3)

Copyright

© 2022, Jimenez-Sainz 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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  1. Judit Jimenez-Sainz
  2. Joshua Mathew
  3. Gemma Moore
  4. Sudipta Lahiri
  5. Jennifer Garbarino
  6. Joseph P Eder
  7. Eli Rothenberg
  8. Ryan B Jensen
(2022)
BRCA2 BRC missense variants disrupt RAD51-dependent DNA repair
eLife 11:e79183.
https://doi.org/10.7554/eLife.79183

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