A role for nucleosome remodellers during resection of deprotected telomeres in yeast [ChIP-seq]

This decision critically depends on DNA end resection, the nucleolytic processing of DSB ends that generates 3′ single-stranded DNA required for homologous recombination while simultaneously suppressing non-homologous end joining. Although the enzymatic mechanisms of resection have been well defined, its regulation by the dynamic, DSB-surrounding chromatin remains poorly understood.

Here, we used the budding yeast cdc13-1 system to investigate how chromatin influences resection after telomere deprotection. Analysis of long-range resection nucleases revealed that Dna2 contributes to telomeric processing, particularly in the absence of Exo1, and acts in conjunction with the STR complex (Sgs1–Top3–Rmi1). Genetic removal of chromatin regulatory factors showed that H2A.Z incorporation did not significantly affect resection, whereas depletion of major nucleosome evictors RSC and SWI/SNF impaired telomere resection.