What is the composition of a telomerase enzyme?

Telomerase is a ribonucleoprotein (RNP) enzyme comprised of two essential core subunits: the telomerase RNA (TER) and telomerase reverse transcriptase protein (TERT). TERT assembles with the integral RNA template within TER to repeatedly synthesize tandem repeats of DNA at the telomeric end of the chromosome.

Is telomerase single stranded?

At least in vitro, telomerase requires a single-stranded 3′ end for strand elongation (11, 23).

What are the two components of telomerase?

Telomerase consists of two essential components: one is the functional RNA component (in humans called hTR or hTERC) (64), which serves as a template for telomeric DNA synthesis; the other is a catalytic protein (hTERT) with reverse transcriptase activity (98, 123, 149, 163).

How many subunits are in telomerase?

The components of the telomerase complex are poorly conserved, but telomerase appears to universally contain three common subunits: a well-conserved catalytic protein called TERT, (TElomere Reverse Transcriptase), a poorly conserved RNA called TER (TElomerase RNA), and an RNA-binding protein or proteins that are …

Do humans produce telomerase?

Most human somatic cells do not produce active telomerase and do not maintain stable telomere length with proliferation. Most or all do have telomerase RNP, which raises the possibility of a second telomerase function independent of DNA synthesis.

Do humans have telomerase?

Telomerase has been detected in human cancer cells and is found to be 10-20 times more active than in normal body cells. This provides a selective growth advantage to many types of tumors.

What is the role of telomerase?

Telomerase is a key enzyme for cell survival that prevents physiological telomere shortening after many rounds of cell division. In most human cancers, reactivation of telomerase is required to enable uncontrolled proliferation of the tumour cells.

What appears to be a negative role of telomerase activity with regard to human health?

Distinct from human stem cells, somatic cells constitute the vast majority of the cells in the human body and lack telomerase activity. The telomerase deficiency of human somatic cells reduces the risk of cancer development, as telomerase fuels uncontrolled cancer cell growth.

What is human telomerase gene?

The TERT gene provides instructions for making one component of an enzyme called telomerase. Telomerase maintains structures called telomeres, which are composed of repeated segments of DNA found at the ends of chromosomes. Telomeres protect chromosomes from abnormally sticking together or breaking down (degrading).

Do human cells express telomerase?

Most human somatic cells do not produce active telomerase and do not maintain stable telomere length with proliferation.

Do humans have telomeres?

Telomeres are the protective caps on the ends of the strands of DNA called chromosomes, which house our genomes. In young humans, telomeres are about 8,000-10,000 nucleotides long. They shorten with each cell division, however, and when they reach a critical length the cell stops dividing or dies.