Taxonomic distribution of proteins containing Tankyrase_bdg_C domains

The tree below includes only several representative species and genera. The complete taxonomic breakdown of all proteins containing Tankyrase_bdg_C domains can be accessed here. Click the counts or percentage values to display the corresponding proteins.

The telomeric poly(ADP-ribose) polymerase, tankyrase 1, contains multiple bindingsites for telomeric repeat binding factor 1 (TRF1) and a novel acceptor, 182-kDa tankyrase-binding protein (TAB182).

Seimiya H, Smith S
J Biol Chem. 2002; 277: 14116-26

Tankyrase 1, a human telomeric poly(ADP-ribose) polymerase, was originallyidentified through its interaction with TRF1, a negative regulator of telomerelength. Tankyrase 1 ADP-ribosylates TRF1 in vitro, and its overexpression inducestelomere elongation in human cancer cells. In addition to its telomericlocalization, tankyrase 1 resides at multiple subcellular sites, suggestingadditional functions for this protein. Here we identify TAB182, a novel tankyrase1-binding protein of 182 kDa. TAB182 displays a complex pattern of subcellularlocalization. TAB182 localizes to the nucleus in a heterochromatic stainingpattern and to the cytoplasm, where it co-stains with the cortical actin network.TAB182 coimmunoprecipitates with tankyrase 1 from human cells and serves as anacceptor of poly(ADP-ribosyl)ation by tankyrase 1 in vitro. Like TRF1, TAB182binds to the ankyrin domain (comprising 24 ankyrin repeats) of tankyrase 1.Surprisingly, dissection of this domain reveals multiple discrete and overlappingbinding sites for TRF1 and TAB182. Thus, we demonstrate five well conservedankyrin repeat clusters in tankyrase 1. Although each of the five ankyrin repeat clusters independently binds to TRF1, only three of the five bind toTAB182. Thesefindings suggest that tankyrase 1 may act as a scaffold for large molecular mass complexes made up of multiple binding proteins. We discuss potential roles fortankyrase 1-mediated higher order complexes at telomeres and at other subcellularsites.