A dynamic molecular link between the telomere length regulator TRF1 and the chromosome end protector TRF2.

Background: Human telomeres are coated by the telomere repeat binding proteins TRF1 and TRF2, which are believed to function independently to regulate telomere length and protect chromosome ends, respectively.

Results: Here, we show that TRF1 and TRF2 are linked via TIN2, a previously identified TRF1-interacting protein, and its novel binding partner TINT1. TINT1 localized to telomeres via TIN2, where it functioned as a negative regulator of telomerase-mediated telomere elongation.