1. Physics of Living Systems
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Single molecule microscopy reveals key physical features of repair foci in living cells

  1. Judith Miné-Hattab  Is a corresponding author
  2. Mathias Heltberg
  3. Marie Villemeur
  4. Chloé Guedj
  5. Thierry Mora
  6. Aleksandra M Walczak
  7. Maxime Dahan
  8. Angela Taddei  Is a corresponding author
  1. Institut Curie, France
  2. Ecole Normale Supérieure, France
  3. École Normale Supérieure, France
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Cite this article as: eLife 2021;10:e60577 doi: 10.7554/eLife.60577

Abstract

In response to double strand breaks (DSB), repair proteins accumulate at damaged sites, forming membrane-less sub-compartments or foci. Here we explored the physical nature of these foci, using single molecule microscopy in living cells. Rad52, the functional homolog of BRCA2 in yeast, accumulates at DSB sites and diffuses ~6 times faster within repair foci than the focus itself, exhibiting confined motion. The Rad52 confinement radius coincides with the focus size: foci resulting from 2 DSBs are twice larger in volume that the ones induced by a unique DSB and the Rad52 confinement radius scales accordingly. In contrast, molecules of the single strand binding protein Rfa1 follow anomalous diffusion similar to the focus itself or damaged chromatin. We conclude that while most Rfa1 molecules are bound to the ssDNA, Rad52 molecules are free to explore the entire focus reflecting the existence of a liquid droplet around damaged DNA.

Data availability

All data generated or analysed during this study are included in the manuscript and supporting files. Source data files are available on zenodo using the following link: https://zenodo.org/record/4495116.

The following data sets were generated

Article and author information

Author details

  1. Judith Miné-Hattab

    UMR 3664 - Nuclear Dynamics, Institut Curie, Paris, France
    For correspondence
    judith.Mine@curie.fr
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0001-9986-4092
  2. Mathias Heltberg

    UMR 3664 - Nuclear Dynamics, Institut Curie, paris, France
    Competing interests
    No competing interests declared.
  3. Marie Villemeur

    UMR3664 - Nuclear Dynamics, Institut Curie, Paris, France
    Competing interests
    No competing interests declared.
  4. Chloé Guedj

    UMR3664 - Nuclear Dynamics, Institut Curie, Paris, France
    Competing interests
    No competing interests declared.
  5. Thierry Mora

    Laboratoire de physique, Ecole Normale Supérieure, Paris, France
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-5456-9361
  6. Aleksandra M Walczak

    Laboratoire de Physique Theorique, École Normale Supérieure, Paris, France
    Competing interests
    Aleksandra M Walczak, Reviewing editor, eLife.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-2686-5702
  7. Maxime Dahan

    Division of Genetics, Genomics & Development, Department of Molecular and Cell Biology, Institut Curie, Paris, France
    Competing interests
    No competing interests declared.
  8. Angela Taddei

    UMR3664, Institut Curie, Paris, France
    For correspondence
    angela.taddei@curie.fr
    Competing interests
    No competing interests declared.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-3217-0739

Funding

Agence Nationale de la Recherche (ANR-11-LABEX-0044 DEEP)

  • Angela Taddei

Agence Nationale de la Recherche (ANR-10-IDEX-0001-02 PSL)

  • Angela Taddei

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

Reviewing Editor

  1. Irene E Chiolo, University of Southern California, United States

Publication history

  1. Received: June 30, 2020
  2. Accepted: January 26, 2021
  3. Accepted Manuscript published: February 5, 2021 (version 1)
  4. Version of Record published: March 1, 2021 (version 2)
  5. Version of Record updated: March 5, 2021 (version 3)

Copyright

© 2021, Miné-Hattab 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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