How does telomerase function as a reverse transcriptase?
How does telomerase function as a reverse transcriptase?
The human telomerase reverse-transcriptase (TERT) gene encodes a rate-limiting catalytic subunit of telomerase, which maintains the length of telomeric DNA and chromosomal stability. Thus, TERT plays a pivotal role in cellular immortalization, cancer development and progression.
Does telomerase use reverse transcriptase?
Telomerase is the enzyme required for the addition of telomeric repeats to the ends of linear chromosomes. It consists of a reverse transcriptase, TERT, that carries its own template in the form of an RNA moiety, TER. In vitro this complex can add telomeric repeats to artificial substrates.
How can telomerase be inhibited?
Anticancer approaches directed at telomerase inhibition are varied, and methods ranging from RNA interference (RNAi) of the TERT catalytic subunit to inhibition of the proteins associated with telomerase at the telomeres have proven to have efficacy against cancer.
Is reverse transcriptase catalytically similar to telomerase?
Our genetic and biochemical analyses show that the reverse transcriptase motifs of Est2p are essential for telomeric DNA synthesis in vivo and in vitro. We propose that telomerase, frequently called “a specialized reverse transcriptase,” is in fact a reverse transcriptase in terms of its catalytic active site.
How is telomerase regulated?
Telomerase expression is also controlled by oncogenes (i.e. c-Myc) as well as tumor suppressors (i.e. WT1). c-Myc influences telomerase expression by binding the two E-boxes present in the hTERT promoter.
How does the telomerase work?
Telomerase, also called telomere terminal transferase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes. Telomerase is found in fetal tissues, adult germ cells, and also tumor cells.
What is the function of the telomerase enzyme?
Telomerase is the enzyme responsible for maintenance of the length of telomeres by addition of guanine-rich repetitive sequences. Telomerase activity is exhibited in gametes and stem and tumor cells.
What is telomerase made of?
Telomerase, also called telomere terminal transferase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes.
How does telomerase play a role?
In egg and sperm cells, an enzyme called telomerase keeps adding more of the repeating sequence onto the end of DNA strands, so that the telomeres in these cells don’t shorten. In other cells, telomerase is less active, leading to the gradual shortening of telomeres over time.
What is the role of telomerase RNA in telomere replenishing?
Telomerase compensates for telomere erosion by replenishing the sequence repeats (TTAGGG in humans) at the 3′ end of telomeric DNA (16).
What triggers telomerase?
In a majority of cancers,telomerase (encoded by theTERT gene), an enzyme that adds telomeres to the ends of chromosomes, becomes activated, usually through mutations in theTERT promoter.
What is telomerase used for?