D) Proposed model for Npl3 function at telomeres. At normal length telomeres, Npl3 associates transiently to telomeres, likely through interaction with the TERRA nascent transcript. As TERRA and R-loops are removed in late S phase, Npl3 is also lost. When telomeres shorten, increased levels of telomeric R-loops and TERRA are a result of decreased Rat1 and RNase H2 localization to telomeres. This has the effect of allowing Npl3 to remain associated with telomeres. The continued presence of Npl3 further promotes R-loop stability, potentially by preventing access of RNA-DNA hybrid removal factors. The continued presence of stable R-loops at telomeres promotes HDR at the short telomeres, likely upon interaction with the oncoming replisome, which in turn prevents the early onset of replicative senescence. 