Biological and Molecular Diversity in Telomerase: Characteristics of hTERT in Human, Vertebrates and Yeast

hTERT (human telomerase reverse transcriptase) is the catalytic subunit of telomerase enzyme, and is essential for its functions. The aim of this review was to compare the TERT in human and other species including microorganism, vertebrates and mammals, in terms of its functions and regulation. According to literature, the catalytic subunit of telomerase in animals contains many conserved domains and residues, which have crucial roles in its functions. Moreover, the structure and biology of human telomerase seem to be more similar to that of dog compared other animals. Thus interestingly, unlike the mouse that is seemingly not a proper model for evaluation of telomerase activity and its regulation, dog may be an appropriate model for the experimental investigations of telomerase function and therapeutic strategies in cancer studies.