TAB182 (tankyrase 1-binding protein of 182 kDa) was identified in a two-hybrid screen in search of tankyrase 1-interacting proteins. Tankyrase 1 is a poly (ADP-ribose) polymerase (PARP) that ribosylates the negative regulator of telomere length, TRF1 (telomere-repeat binding factor). Ribosylation of TRF1 has been shown to result in the inhibition of TRF1 binding and an induction of telomere elongation. TAB182 and TRF1 bind multiple discrete and overlapping sites of the tankyrase 1 ankyrin domain. This finding suggests that TAB182 may act as a scaffold to mediate higher order protein complex formation at telomeres. TAB182 has also been suggested to serve a role in the cytoplasm as it has been found to localize to the cytoplasmic cortical actin network.
