Single molecule microscopy reveals key physical features of repair foci in living cells

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 a...

Full description

Saved in:
Bibliographic Details
Published in:eLife Vol. 10
Main Authors: Miné-Hattab, Judith, Heltberg, Mathias, Villemeur, Marie, Guedj, Chloé, Mora, Thierry, Walczak, Aleksandra M, Dahan, Maxime, Taddei, Angela
Format: Journal Article
Language:English
Published: England eLife Sciences Publications Ltd 05.02.2021
eLife Sciences Publication
eLife Sciences Publications, Ltd
Subjects:
BRCA2 protein
Cell cycle
Chromatin
DNA Damage
DNA repair
Life Sciences
liquid-liquid phase separation
Microscopy
nuclear sub-compartments
Physics of Living Systems
Population
Proteins
Rad52 DNA Repair and Recombination Protein - chemistry
Rad52 protein
Replication Protein A - chemistry
Saccharomyces cerevisiae - chemistry
Saccharomyces cerevisiae Proteins - chemistry
Single Molecule Imaging
single molecule microscopy
single particle tracking
Yeast
nuclear sub-compartments
liquid-liquid phase separation
single particle tracking
single molecule microscopy
DNA repair
physics of living systems
S. cerevisiae
ISSN:2050-084X, 2050-084X
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 14
content type line 23
PMCID: PMC7924958
Deceased.
ISSN:2050-084X
2050-084X
DOI:10.7554/eLife.60577