Rad59-Facilitated Acquisition of Y′ Elements by Short Telomeres Delays the Onset of Senescence

• DOI: 10.1371/journal.pgen.1004736
• Publication Date: 2014-11-06T19:10:43Z
• Authors: Dmitri Churikov; Ferose Charifi; Marie-Noëlle Simon; Vincent Géli
• Keywords: RAD52; Subtelomere; Senescence

Telomerase-negative yeasts survive via one of the two Rad52-dependent recombination pathways, which have distinct genetic requirements. Although telomere pattern type I and II survivors is well characterized, mechanistic details short rearrangement into highly evolved observed in are still missing. Here, we analyze immediate events taking place at abruptly shortened VII-L native telomeres. We show that telomeres engage pairing with internal Rap1-bound TG1–3-like tracts present between subtelomeric X Y′ elements, followed by BIR-mediated non-reciprocal translocation element terminal TG1–3 repeats from donor end onto telomere. found choice was not random, since both engineered VI-R acquired elements partially overlapping sets specific chromosome ends. repair associated transient delay cell divisions, on did require Mec1-dependent checkpoint. Furthermore, homeologous other ends largely independent Rad51, but instead it facilitated Rad59 stimulates Rad52 strand annealing activity. Therefore, during presenescence genetically separable Rad51-dependent amplification process occurs later survivor formation. Rad59-facilitated translocations X-only onset senescence while preparing ground for