The pleiotropy of telomerase against cell death

The end of eukaryotic genomic DNA is capped by a specialized structure called as “telomere”, which con-sists of the repetitive array of nucleotide sequence, TTAGGG, in humans and mice, and a variety of bind-ing proteins. Telomerase is a ribonucleoprotein (RNP) complex responsible for the elongation of telomeres to maintain the genomic integrity, and is composed of telomerase reverse transcriptase (TERT), telomerase RNA component (TERC), and their associated factors regulating the catalytic activity of telomerase. Al-though it is now apparent that telomerase protects cells from apoptosis via the maintenance of genomic integrity by stabilizing telomeres, our understanding for the physiological role of telomerase is yet far from completion, and emerging evidence suggests that te-lomerase has additional extratelomeric roles in medi-ating cell survival and anti-apoptotic functions against various cytotoxic stresses. Here we summarize and discuss how telomerase and telomeres are involved in mediating cellular protection against apoptosis. Keywords: Anti-apoptotic; Apoptosis; Cell Death; Extrate-lomeric; Survival; Telomerase; Telomere; TERT; TERC.