Telomerase
Telomerase is an enzyme that rebuilds the caps on your chromosome ends. Technically, it is a ribonucleoprotein 'reverse transcriptase'. It pairs a protein part (TERT) with an RNA template (TERC). Using that template, it adds TTAGGG repeats to chromosome ends, countering the shortening that comes with cell division. Telomerase is highly active in germline, stem, and most cancer cells. But it is largely switched off in your adult body tissues. In longevity research, switching telomerase back on has extended healthspan in mice. But it carries cancer risk, because most human tumors depend on telomerase for unlimited growth.
Last reviewed:
This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer
Sources
- Greider CW, Blackburn EH. (1985). Identification of a specific telomere terminal transferase activity in Tetrahymena extracts. *Cell*doi:10.1016/0092-8674(85)90170-9
- Bernardes de Jesus B, Vera E, Schneeberger K, et al.. (2012). Telomerase gene therapy in adult and old mice delays aging and increases longevity without increasing cancer. *EMBO Molecular Medicine*doi:10.1002/emmm.201200245