Telomerase reverse transcriptase
From Ganfyd
Telomere reverse transcriptase is an RNA-dependent enzyme that adds deoxynucleotides to DNA. Its function is to restore the length of the telomeres.
During cell growth and subsequent division, the DNA polymerases that are responsible for replicating the genetic information stored in chromosomes are unable to replicate the information at the very end of the chromosomes (the telomeres). The telomeres consist of a particular type of variable number tandem repeats. With each subsequent replication, the telomeres become shorter, a process sometimes compared to the fraying of the protective tips of the shoe laces. With time, this shortening can be enough to affect cell replication - either by causing the cell to undergo apoptosis or to become senescent.
Clinical conditions associated with its dysfunction include:
- Telomerase reverse transcriptase protein subunit (TERT, TCS1, EST2) on 5p15.33 5p15.2
- Cri-du-chat syndrome (full features are due to TERT deletion)
- Acquired aplastic anaemia
- Association between a -1327T-C polymorphism in the promoter region of the TERT gene and coronary artery disease[1]
- Idiopathic pulmonary fibrosis
- Telomerase RNA component (TERC, TRC3) on 3q21-q28
- Autosomal dominant dyskeratosis congenita and aplastic anaemia caused by mutations of the RNA encoding gene TERC
- Dyskerin which is involved in RNA processing, presumably including the telomerase RNA component.
- X-linked dyskeratosis congenita is caused by mutations of the dyskerin (DKC1) gene on Xq28 causing abnormal
- Hoyeraal-Hreidarsson syndrome
