telomerase RNA component

Normal function

ال TERC 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). In most cells, telomeres become progressively shorter as the cell divides. After a certain number of cell divisions, the telomeres become so short that they trigger the cell to stop dividing or to self-destruct (undergo apoptosis). Telomerase counteracts the shortening of telomeres by adding small repeated segments of DNA to the ends of chromosomes each time the cell divides.

In most types of cells, telomerase is either undetectable or active at very low levels. However, telomerase is highly active in cells that divide rapidly, such as cells that line the lungs and gastrointestinal tract, cells in bone marrow, and cells of the developing fetus. Telomerase allows these cells to divide many times without becoming damaged or undergoing apoptosis. Telomerase is also abnormally active in cancer cells, which grow and divide without control or order.

The telomerase enzyme consists of two major components that work together. The component produced from the TERC gene is known as hTR. The hTR component is an RNA molecule, a chemical cousin of DNA. It provides a template for creating the repeated sequence of DNA that telomerase adds to the ends of chromosomes. The other major component of telomerase, which is produced from a gene called TERT, is known as hTERT. The function of hTERT is to add the new DNA segment to chromosome ends.

Conditions referring to this gene or chromosome

• التليف الرئوي مجهول السبب

• Dyskeratosis congenita

Other names

hTERC

hTR

SCARNA19

small Cajal body-specific RNA 19

telomerase RNA

telomerase RNA component gene

قلس ثلاثي الشرفات (TR)

TRC3