What is telomerase?

Telomerase is an enzyme that plays a crucial role in maintaining the length of telomeres, which are repetitive sequences of DNA located at the ends of chromosomes. These telomeres serve to protect chromosome ends from degradation and prevent them from being recognized as broken DNA by the cell's repair machinery. Over time, with each cell division, telomeres shorten due to the inability of the DNA replication machinery to fully replicate the ends of linear chromosomes. Telomerase counters this shortening by adding nucleotide sequences back to the ends of the telomeres, thus extending their length and allowing cells to divide without losing important genetic information.

In certain cells, such as stem cells and germ cells, telomerase activity is high, allowing these cells to divide many times. Conversely, in most somatic cells, telomerase is not active, leading to eventual cell aging and senescence as telomeres become critically short. This explains the significance of telomerase in cellular aging and its potential link to cancer, where some tumors reactivate telomerase to sustain continuous division.

Understanding the function of telomerase is essential for insights into cellular aging, cancer biology, and potential therapeutic approaches targeting this enzyme in the treatment of age-related diseases and cancer.