RT Journal Article SR Electronic T1 Loss of Rap1 supports recombination-based telomere maintenance independent of RNA-DNA hybrids in fission yeast JF bioRxiv FD Cold Spring Harbor Laboratory SP 458968 DO 10.1101/458968 A1 Yan Hu A1 Henrietta W. Bennett A1 Na Liu A1 Martin Moravec A1 Jessica F. Williams A1 Claus M. Azzalin A1 Megan C. King YR 2018 UL http://biorxiv.org/content/early/2018/11/01/458968.abstract AB To investigate the molecular changes needed for cells to maintain their telomeres by recombination, we monitored telomere appearance during serial culture of fission yeast cells lacking the telomerase recruitment factor Ccq1. Rad52 is loaded onto critically short telomeres shortly after germination despite continued telomere erosion, suggesting that recruitment of recombination factors is not sufficient to maintain telomeres in the absence of telomerase function. Instead, survivor formation coincides with the derepression of telomeric repeat-containing RNA (TERRA). Degradation of telomere-associated TERRA in this context drives a severe growth crisis, ultimately leading to a distinct type of linear survivor with altered cytological telomere characteristics and the eviction of the shelterin component Rap1 (but not the TRF1/TRF2 orthologue, Taz1) from the telomere. We demonstrate that deletion of Rap1 is protective, preventing the growth crisis that is otherwise triggered by degradation of telomere-engaged TERRA in survivors with linear chromosomes. Thus, modulating the stoichiometry of shelterin components appears to support recombination-dependent survivors to persist in the absence of telomere-engaged TERRA.