TelomeraseKomplexes

The telomerase complex is a ribonucleoprotein enzyme responsible for the maintenance of telomere length in eukaryotic chromosomes. Telomeres are repetitive nucleotide sequences at the ends of chromosomes that protect the ends from degradation and fusion with neighboring chromosomes. The telomerase complex is composed of two main components: the telomerase RNA (TERC) and the telomerase reverse transcriptase (TERT).

TERC is a non-coding RNA that serves as the template for telomerase to extend telomeres. It is transcribed from the TERC gene and forms a stable RNA:protein complex with TERT. TERT is the catalytic subunit of the telomerase complex, responsible for the addition of nucleotides to the 3' end of telomeres. It is encoded by the TERT gene and contains a reverse transcriptase domain that allows it to synthesize DNA from an RNA template.

The telomerase complex is active in most human cells, but its activity is tightly regulated. In most somatic cells, telomerase activity is low or absent, leading to the progressive shortening of telomeres with each cell division. This is thought to contribute to cellular senescence and aging. In contrast, telomerase is highly active in germ cells and stem cells, allowing these cells to maintain their telomere length and undergo unlimited division.

Telomerase activity has been implicated in various diseases, including cancer. In cancer cells, telomerase activity is often upregulated, leading to the maintenance of telomere length and the ability to divide indefinitely. This is thought to contribute to the uncontrolled growth and proliferation of cancer cells. Therefore, telomerase is a potential target for cancer therapy, and inhibitors of telomerase activity are being developed as anticancer agents.