| Primary Identifier | IPR003545 | Type | Family |
| Short Name | Telomerase_RT |
| description | Telomerase is an enzyme that, in certain cells, maintains the physical endsof chromosomes (telomeres) during replication. In somatic cells, replicationof the lagging strand requires the continual presence of an RNA primerapproximately 200 nucleotides upstream, which is complementary to thetemplate strand. Since there is a region of DNA less than 200 base pairsfrom the end of the chromosome where this is not possible, the chromosome iscontinually shortened. However, there is a surplus of repetitive DNA at the ends, the telomeres, that protects against the erosion of gene-encoding DNA.Telomerase is a ribonucleoprotein (RNP) that synthesises the telomeric DNArepeats. The telomerase RNA subunit provides the template for synthesis ofthese repeats. There are 2 protein components of the RNP: the catalyticsubunit is known as telomerase reverse transcriptase (TERT). The reversetranscriptase domain is located in the C-terminal region of the TERTpolypeptide and single amino acid substitutions in this region lead totelomere shortening and senescence [].Telomerase is not normally expressed in somatic cells and it has beensuggested that exogenous TERT may extend the lifespan of, or evenimmortalise, the cell. However, recent studies have shown that telomeraseactivity can be induced by a number of oncogenes []. Conversely, theoncogene c-myc can be activated in human TERT immortalised cells []. |
