ATM signaling modulates cohesin behavior in meiotic prophase and proliferating cells

The authors show that the assembly of the meiotic chromosome axis in worms depends on activation of the master DNA-damage response kinase ATM, which leads to destabilization of the cohesin-unloader WAPL. Similar ATM-dependent WAPL inhibition also occurs in cohesin-rich genomic regions upon DNA-damage induction. Cohesins are ancient and ubiquitous regulators of chromosome architecture and function, but their diverse roles and regulation remain poorly understood. During meiosis, chromosomes are reorganized as linear arrays of chromatin loops around a cohesin axis. This unique organization underlies homolog pairing, synapsis, double-stranded break induction, and recombination. We report that axis assembly in Caenorhabditiselegans is promoted by DNA-damage response (DDR) kinases that are activated at meiotic entry, even in the absence of DNA breaks. Downregulation of the cohesin-destabilizing factor WAPL-1 by ATM-1 promotes axis association of cohesins containing the meiotic kleisins COH-3 and COH-4. ECO-1 and PDS-5 also contribute to stabilizing axis-associated meiotic cohesins. Further, our data suggest that cohesin-enriched domains that promote DNA repair in mammalian cells also depend on WAPL inhibition by ATM. Thus, DDR and Wapl seem to play conserved roles in cohesin regulation in meiotic prophase and proliferating cells.

Automated summary

The authors demonstrate that the assembly of the meiotic chromosome axis in worms relies on the activation of the master DNA-damage response kinase ATM, leading to destabilization of the cohesin-unloader WAPL. Similar ATM-dependent WAPL inhibition also occurs in cohesin-rich genomic regions upon DNA-damage induction.