Proteins (TRFs) that bind to the TTAGGG tandem repeats of telomeres as homodimers, recruit other proteins into the shelterin complex, and control telomere length by inhibiting telomerase. TRF1 (439 aa) is related to the proto-oncogene myb. TRF2 is similar and coexpressed: it is presumed to have a slightly different role. TRF2 dysfunction results in the exposure of the telomere ends and activation of ATM (ataxia telangiectasia mutated)-mediated DNA damage response. The binding of TRF1 to DNA is inhibited by the poly(ADP-ribose) polymerase (PARP) activity of tankyrase-1.
Subjects: Medicine and Health.