Mutational phospho-mimicry reveals a regulatory role for the XRCC4 and XLF C-terminal tails in modulating DNA bridging during classical non-homologous end joining

  1. Davide Normanno
  2. Aurélie Négrel
  3. Abinadabe J de Melo
  4. Stéphane Betzi
  5. Katheryn Meek
  6. Mauro Modesti  Is a corresponding author
  1. Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, France
  2. Sigma Aldrich, France
  3. Michigan State University, United States

Abstract

XRCC4 and DNA Ligase 4 (LIG4) form a tight complex that provides DNA ligase activity for classical non-homologous end joining (the predominant DNA double-strand break repair pathway in higher eukaryotes) and is stimulated by XLF. Independently of LIG4, XLF also associates with XRCC4 to form filaments that bridge DNA. These XRCC4/XLF complexes rapidly load and connect broken DNA, thereby stimulating intermolecular ligation. XRCC4 and XLF both include disordered C-terminal tails that are functionally dispensable in isolation but are phosphorylated in response to DNA damage by DNA-PK and/or ATM. Here we concomitantly modify the tails of XRCC4 and XLF by substituting fourteen previously identified phosphorylation sites with either alanine or aspartate residues. These phospho-blocking and -mimicking mutations impact both the stability and DNA bridging capacity of XRCC4/XLF complexes, but without affecting their ability to stimulate LIG4 activity. Implicit in this finding is that phosphorylation may regulate DNA bridging by XRCC4/XLF filaments.

Article and author information

Author details

  1. Davide Normanno

    Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Marseilles, France
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-4740-5542
  2. Aurélie Négrel

    Sigma Aldrich, Saint Quentin Fallavier, France
    Competing interests
    The authors declare that no competing interests exist.
  3. Abinadabe J de Melo

    Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.
  4. Stéphane Betzi

    Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Marseille, France
    Competing interests
    The authors declare that no competing interests exist.
  5. Katheryn Meek

    College of Veterinary Medicine, Michigan State University, East Lansing, United States
    Competing interests
    The authors declare that no competing interests exist.
  6. Mauro Modesti

    Cancer Research Center of Marseille, CNRS UMR7258, Inserm U1068, Marseille, France
    For correspondence
    mauro.modesti@inserm.fr
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-4964-331X

Funding

Fondation ARC pour la Recherche sur le Cancer (SFI20121205867)

  • Mauro Modesti

U.S. Public Health Service (AI048758)

  • Katheryn Meek

Institut National Du Cancer (PLBIO13-099)

  • Mauro Modesti

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

Reviewing Editor

  1. Barry P Sleckman, Weill Cornell Medical College, United States

Version history

  1. Received: November 2, 2016
  2. Accepted: May 12, 2017
  3. Accepted Manuscript published: May 13, 2017 (version 1)
  4. Version of Record published: June 12, 2017 (version 2)
  5. Version of Record updated: June 13, 2017 (version 3)

Copyright

© 2017, Normanno 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. Davide Normanno
  2. Aurélie Négrel
  3. Abinadabe J de Melo
  4. Stéphane Betzi
  5. Katheryn Meek
  6. Mauro Modesti
(2017)
Mutational phospho-mimicry reveals a regulatory role for the XRCC4 and XLF C-terminal tails in modulating DNA bridging during classical non-homologous end joining
eLife 6:e22900.
https://doi.org/10.7554/eLife.22900

Share this article

https://doi.org/10.7554/eLife.22900

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