PT  - JOURNAL ARTICLE
AU  - Coline Arnould
AU  - Vincent Rocher
AU  - Thomas Clouaire
AU  - Pierre Caron
AU  - Philippe. E. Mangeot
AU  - Emiliano. P. Ricci
AU  - Raphael Mourad
AU  - Daan Noordermeer
AU  - Gaëlle Legube
TI  - Loop extrusion as a mechanism for DNA Double-Strand Breaks repair foci formation
AID  - 10.1101/2020.02.12.945311
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.02.12.945311
4099  - http://biorxiv.org/content/early/2020/02/13/2020.02.12.945311.short
4100  - http://biorxiv.org/content/early/2020/02/13/2020.02.12.945311.full
AB  - DNA Double-Strand Breaks (DSBs) repair is essential to safeguard genome integrity. Upon DSBs, the ATM PI3K kinase rapidly triggers the establishment of megabase-sized, γH2AX-decorated chromatin domains which further act as seeds for the formation of DNA Damage Response (DDR) foci1. How these foci are rapidly assembled in order to establish a “repair-prone” environment within the nucleus is yet unclear. Topologically Associating Domains (TADs) are a key feature of 3D genome organization that regulate transcription and replication, but little is known about their contribution to DNA repair processes2,3. Here we found that TADs are functional units of the DDR, instrumental for the correct establishment of γH2AX/53BP1 chromatin domains in a manner that involves one-sided cohesin-mediated loop extrusion on both sides of the DSB. We propose a model whereby H2AX-containing nucleosomes are rapidly phosphorylated as they actively pass by DSB-anchored cohesin. Our work highlights the critical impact of chromosome conformation in the maintenance of genome integrity and provides the first example of a chromatin modification established by loop extrusion.