It's getting HOT at telomeres.

How telomerase and telomeres are brought together to alleviate telomere shortening and preserve genome integrity in the cell remains incompletely understood. A study in The EMBO Journal now identifies HOT1 as a direct telomere repeat binding protein that contributes to telomerase-mediated telomere elongation, likely by bridging telomere and telomerase interactions. In contrast to the usually circular DNA of prokaryotes, eukaryotes maintain their genetic information in the form of linear chromosomes, whose extremities assemble complex structures called telomeres, consisting of repetitive DNA sequences and associated proteins. Telomeres serve two major functions: (1) to prevent chromosome ends from being recognized as broken DNA and triggering checkpoint responses, which would lead to deleterious chromosome endto-end fusions and (2) to protect genetic material from degradation by cellular nucleases. Protection of chromosome ends from fusion is coordinated by the shelterin complex, which consists of six proteins: TRF1, TRF2, POT1, RAP1, TIN2 and TPP1. Both TRF1 and TRF2 can bind directly to doublestranded telomeric DNAwith sequence specificity, while POT1 binds to single-stranded TTAGGG repeats. The shelterin complex acts to suppress DNA damage responses at telomeres, which would result from recognition of the ends of linear chromosomes as double-strand breaks. As this function is required at all telomeres, almost throughout the cell cycle, the shelterin proteins are intrinsic and permanent components of telomeres (reviewed in Martı́nez and Blasco, 2011). The second challenge of functional telomeres is to protect the genetic material from degradation. To achieve this, telomeric repeats must be constantly replenished at chromosome ends to prevent attrition of the telomeric tract. This is facilitated by transient telomere uncapping during every S phase of the cell cycle, when telomeres are replicated