SAM (sterile alpha motif) domain of Tankyrase1,2 subfamily is a protein-protein interaction domain. In addition to the SAM domain, proteins of this group have ankyrin repeats and a ADP- ribosyltransferase (poly-(ADP-ribose) synthase) domain. Tankyrases can polymerize through their SAM domains forming homoligomers and these complexes are disrupted by autoribosylation. Tankyrases apparently act as master scaffolding proteins and thus may interact simultaneously with multiple proteins, in particular with TRF1, NuMA, IRAP and Grb14 (ankyrin repeats are involved in these interactions). Tankyrases participate in a variety of cell signaling pathways as effector molecules. Their functions are different depending on the intracellular location: at telomeres they play a role in the regulation of telomere length via control of telomerase access to telomeres, at centrosomes they promote spindle assembly/disassembly, in Golgi vesicles they participate in the regulation of vesicle trafficking and Golgi dynamics. Tankyrase 1 may be of interest as new potential target for telomerase-directed cancer therapy.
Jiyao W et al.(2023). "The conserved domain database in 2023.",