A new Riff: Rif1 eats its cake and has it too.

Abstract

Rif1 protein is present in eukaryotic cells from yeast to human. In yeast, Rif1 is important for telomere homeostasis. Despite conservation in its domain organization, human Rif1 is not part of the telomere complex but was recently reported to work at DNA double‐strand breaks (DSBs) with 53BP1 to inhibit 5′ strand degradation (resection) and stimulate a subset of nonhomologous end‐joining (NHEJ) reactions. Martina et al report in this issue of EMBO reports that yeast Rif1 is also recruited to DSBs, but in contrast to its human counterpart, it promotes resection. The authors propose that Rif1 stimulates resection by limiting the access of Rad9, an ortholog of 53BP1, to DSBs.