Telomerase

Definition

Telomerase is a ribonucleoprotein enzyme complex that helps maintain telomeres, the protective DNA- protein structures at chromosome ends. It contains a reverse transcriptase component and an RNA template that can be used to add telomeric DNA repeats to chromosome ends. [1] [2] [3]

Why It Matters in Ageing Research

Telomerase matters because telomere maintenance influences cellular replication, tissue renewal, stem-cell function, genome stability, and cellular senescence. Low telomerase activity can contribute to telomere shortening in many somatic cells, while high or reactivated telomerase activity is common in many cancers. This makes telomerase important in ageing biology, but also a clear example of the trade-offs between regeneration and cancer risk. [4] [5] [6]

Common Confusion

• Telomerase is not the same as telomeres; telomeres are chromosome-end structures, while telomerase is an enzyme that can help maintain them.
• More telomerase is not automatically better, because telomerase activation can interact with cancer biology.
• Telomerase activity varies by cell type and is not a simple standalone measure of biological age.

Related Reading

• Telomeres
• Hallmarks of Ageing
• Cellular Senescence
• Genomic Instability

References

1. Greider, C. W., & Blackburn, E. H. (1985). Identification of a specific telomere terminal transferase activity in Tetrahymena extracts. https://doi.org/10.1016/0092-8674(85)90170-9
2. Blackburn, E. H., Greider, C. W., & Szostak, J. W. (2006). Telomeres and telomerase: the path from maize, Tetrahymena and yeast to human cancer and ageing. https://doi.org/10.1038/nm1006-1133
3. Schmidt, J. C., & Cech, T. R. (2015). Human telomerase: biogenesis, trafficking, recruitment, and activation. https://doi.org/10.1101/gad.263863.115
4. Lopez-Otin, C., et al. (2013). The Hallmarks of Aging. https://doi.org/10.1016/j.cell.2013.05.039
5. Bernardes de Jesus, B., & Blasco, M. A. (2013). Telomerase at the intersection of cancer and aging. https://doi.org/10.1016/j.tig.2013.05.003
6. Shay, J. W., & Wright, W. E. (2019). Telomeres and telomerase: three decades of progress. https://doi.org/10.1038/s41576-019-0099-1