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

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

Version 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.

Metrics

  • 3,462
    views
  • 509
    downloads
  • 57
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Judith Miné-Hattab
  2. Mathias Heltberg
  3. Marie Villemeur
  4. Chloé Guedj
  5. Thierry Mora
  6. Aleksandra M Walczak
  7. Maxime Dahan
  8. Angela Taddei
(2021)
Single molecule microscopy reveals key physical features of repair foci in living cells
eLife 10:e60577.
https://doi.org/10.7554/eLife.60577

Share this article

https://doi.org/10.7554/eLife.60577

Further reading

    1. Cell Biology
    2. Physics of Living Systems
    Qin Ni, Sean X Sun
    Insight

    An influx of water molecules can help immune cells called neutrophils to move to where they are needed in the body.

    1. Cell Biology
    2. Physics of Living Systems
    Tamas L Nagy, Evelyn Strickland, Orion D Weiner
    Research Article

    While the involvement of actin polymerization in cell migration is well-established, much less is known about the role of transmembrane water flow in cell motility. Here, we investigate the role of water influx in a prototypical migrating cell, the neutrophil, which undergoes rapid, directed movement to sites of injury, and infection. Chemoattractant exposure both increases cell volume and potentiates migration, but the causal link between these processes are not known. We combine single-cell volume measurements and a genome-wide CRISPR screen to identify the regulators of chemoattractant-induced neutrophil swelling, including NHE1, AE2, PI3K-gamma, and CA2. Through NHE1 inhibition in primary human neutrophils, we show that cell swelling is both necessary and sufficient for the potentiation of migration following chemoattractant stimulation. Our data demonstrate that chemoattractant-driven cell swelling complements cytoskeletal rearrangements to enhance migration speed.