1. Biochemistry and Chemical Biology
  2. Chromosomes and Gene Expression
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Small-molecule inhibitors identify the RAD52-ssDNA interaction as critical for recovery from replication stress and for survival of BRCA2 deficient cells

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Cite this article as: eLife 2016;5:e14740 doi: 10.7554/eLife.14740

Abstract

The DNA repair protein RAD52 is an emerging therapeutic target of high importance for BRCA-deficient tumors. Depletion of RAD52 is synthetically lethal with defects in tumor suppressors BRCA1, BRCA2 and PALB2. RAD52 also participates in recovery of the stalled replication forks. Anticipating that ssDNA binding activity underlies the RAD52 cellular functions, we carried out a high throughput screening campaign to identify compounds that disrupt the RAD52-ssDNA interaction. Lead compounds were confirmed as RAD52 inhibitors in biochemical assays. Computational analysis predicted that these inhibitors bind within the ssDNA-binding groove of the RAD52 oligomeric ring. The nature of the inhibtor-RAD52 complex was validated through an in silico screening campaign, culminating in the discovery of an additional RAD52 inhibitor. Cellular studies with our inhibitors showed that the RAD52-ssDNA interaction enables its function at stalled replication forks, and that the inhibition of RAD52-ssDNA binding acts additively with BRCA2 or MUS81 depletion in cell killing.

Article and author information

Author details

  1. Sarah R Hengel

    Department of Biochemistry, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  2. Eva Malacaria

    Department of Environment and Health, Istituto Superiore di Sanita, Rome, Italy
    Competing interests
    The authors declare that no competing interests exist.
  3. Laura Folly da Silva Constantino

    Department of Pharmaceutical Sciences and Experimental Therapeutics, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. Fletcher E Bain

    Department of Biochemistry, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  5. Andrea Diaz

    Department of Biochemistry, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Brandon G Koch

    Department of Biochemistry, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  7. Liping Yu

    Department of Biochemistry, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  8. Meng Wu

    Department of Biochemistry, University of Iowa, Iowa City, United States
    Competing interests
    The authors declare that no competing interests exist.
  9. Pietro Pichierri

    Department of Environment and Health, Istituto Superiore di Sanita, Rome, Italy
    Competing interests
    The authors declare that no competing interests exist.
  10. Michael Ashley Spies

    Department of Biochemistry, University of Iowa, Iowa City, United States
    For correspondence
    m-ashley-spies@uiowa.edu
    Competing interests
    The authors declare that no competing interests exist.
  11. Maria Spies

    Department of Biochemistry, University of Iowa, Iowa City, United States
    For correspondence
    maria.g.spies@gmail.com
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-7375-8037

Funding

American Cancer Society (RSG-09-182-01-DMC)

  • Maria Spies

National Institutes of Health (NIH R01-GM097373)

  • Michael Ashley Spies

National Institutes of Health (1S10RR029274-01)

  • Meng Wu

Itallian Association of Cancer Research (AIRC, IG13398)

  • Pietro Pichierri

Nando-Peretti Foundation (2012-113)

  • Pietro Pichierri

CAPES

  • Laura Folly da Silva Constantino

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

Reviewing Editor

  1. Taekjip Ha, Johns Hopkins University School of Medicine, United States

Publication history

  1. Received: February 1, 2016
  2. Accepted: July 18, 2016
  3. Accepted Manuscript published: July 19, 2016 (version 1)
  4. Version of Record published: August 12, 2016 (version 2)

Copyright

© 2016, Hengel 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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