Telomere

Definition

Telomeres are repetitive nucleotide sequences (TTAGGG in humans) capping the ends of chromosomes that protect genetic material from degradation, end-to-end fusion, and recognition as DNA damage. They function as a biological clock — shortening with each cell division and eventually triggering cellular senescence when critically depleted.

Structure and Function

Human telomeres consist of thousands of TTAGGG repeats bound by a protein complex called shelterin, which prevents the chromosome ends from being recognised as DNA double-strand breaks. Each cell division results in the loss of 50–200 base pairs of telomeric DNA due to the “end replication problem” — DNA polymerase cannot fully replicate the 3′ end of linear chromosomes.

Telomerase, a ribonucleoprotein enzyme containing a reverse transcriptase component (TERT) and an RNA template (TERC), can extend telomeres by adding TTAGGG repeats. Telomerase is active in stem cells, germ cells, and most cancer cells, but has minimal activity in most somatic cells.

Telomere Length and Ageing

Telomere shortening is considered a hallmark of biological ageing. When telomeres reach a critical length, cells enter replicative senescence — permanently exiting the cell cycle. Accelerated telomere attrition is associated with chronic stress, inflammation, oxidative damage, and various age-related diseases.

Relevance to Peptide Research

Epitalon (epithalamin tetrapeptide) is the most directly relevant research peptide, studied for its reported ability to activate telomerase and extend telomere length in cell culture models. This connection between a short synthetic peptide and telomere biology has generated significant research interest in the longevity peptide field. Other peptides involved in anti-oxidant defence and mitochondrial function (Humanin, MOTS-c, GHK-Cu) may indirectly influence telomere maintenance by reducing oxidative damage to telomeric DNA.

Related Peptides

Peptide profiles that reference “Telomere” in their research content.