posted on 2023-06-09, 17:50authored byElda Cannavo, Dominic Johnson, Sara Andres, Vera Kissling, Julia Reinert, Valerie Garcia, Dorothy Erie, Daniel Hess, Nicolas Thomä, Radoslav Enchev, Matthias Peter, Scott Williams, Matt NealeMatt Neale, Petr Cejka
DNA end resection plays a critical function in DNA double-strand break repair pathway choice. Resected DNA ends are refractory to end-joining mechanisms and are instead channeled to homology-directed repair. Using biochemical, genetic, and imaging methods, we show that phosphorylation of Saccharomyces cerevisiae Sae2 controls its capacity to promote the Mre11-Rad50-Xrs2 (MRX) nuclease to initiate resection of blocked DNA ends by at least two distinct mechanisms. First, DNA damage and cell cycle-dependent phosphorylation leads to Sae2 tetramerization. Second, and independently, phosphorylation of the conserved C-terminal domain of Sae2 is a prerequisite for its physical interaction with Rad50, which is also crucial to promote the MRX endonuclease. The lack of this interaction explains the phenotype of rad50S mutants defective in the processing of Spo11-bound DNA ends during meiotic recombination. Our results define how phosphorylation controls the initiation of DNA end resection and therefore the choice between the key DNA double-strand break repair mechanisms.
Funding
Control and impact of meiotic DNA resection on recombination and genome stability; G1538; BBSRC-BIOTECHNOLOGY & BIOLOGICAL SCIENCES RESEARCH COUNCIL; BB/M010279/1
Repair of covalent protein-linked DNA double-strand breaks (ext to R33Y - but separate grant); G0866; ROYAL SOCIETY; UF110009
Spatial regulation of meiotic recombination; WELLCOME TRUST; 200843/Z/16/Z
Biochemical reconstitution of DNA repair reactions on intact chromatin; G0986; EUROPEAN UNION; 311336