Cohesin drives chromatin scanning during the RAD51-mediated homology search.

ABSTRACT: Cohesin folds genomes into chromatin loops, the roles of which are under debate. We found that double-strand breaks (DSBs) induce de novo formation of chromatin loops in human cells, with the loop base positioned at the DSB site. These loops form in the S and G₂ phases of the cell cycle during homologous recombination repair, concomitantly with DNA end resection and radiation-sensitive protein 51 (RAD51) recruitment. RAD51 shows a broad (megabase-sized) chromatin domain reflective of the homology search. This domain is regulated by cohesin unloader and overlaps with chromatin regions reeled through the break-anchored loop, suggesting that loop extrusion regulates the homology search. Indeed, depletion of the loop-extruding cohesin subunit NIPBL lowers homologous recombination in

SUBMITTER: Marin-Gonzalez A 

PROVIDER: S-EPMC12701822 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature