Telomerase reverse transcriptase

Telomerase reverse transcriptase (abbreviated to TERT, or hTERT in humans) is a catalytic subunit of the <a href="/facts/Enzyme/DSI1Fh7y">enzyme</a> <a href="/facts/Telomerase/tUtWedEg">telomerase</a>, which, together with the <a href="/facts/Telomerase_RNA_component/j3yKwYBF">telomerase RNA component</a> (TERC), comprises the most important unit of the telomerase complex.
Telomerases are part of a distinct subgroup of RNA-dependent polymerases. Telomerase lengthens telomeres in <a href="/facts/DNA/nB89Iauz">DNA</a> strands, thereby allowing senescent <a href="/facts/Cell_(biology)/bLM9UQvy">cells</a> that would otherwise become postmitotic and undergo <a href="/facts/Apoptosis/8dVzSm4y">apoptosis</a> to exceed the <a href="/facts/Hayflick_limit/2zat9aY9">Hayflick limit</a> and become potentially immortal, as is often the case with cancerous cells. To be specific, TERT is responsible for catalyzing the addition of <a href="/facts/Nucleotides/pQKEwlJI">nucleotides</a> in a TTAGGG sequence to the ends of a <a href="/facts/Chromosome/FRGf11FC">chromosome</a>'s <a href="/facts/Telomere/RQ4Gp9LT">telomeres</a>. This addition of repetitive <a href="/facts/DNA/nB89Iauz">DNA</a> sequences prevents degradation of the chromosomal ends following multiple rounds of replication.
hTERT absence (usually as a result of a <a href="/facts/Chromosome/FRGf11FC">chromosomal</a> <a href="/facts/Mutation/Ee4NnWbY">mutation</a>) is associated with the disorder <a href="/facts/Cri_du_chat/xgKJxuyy">Cri du chat</a>.

Telomerase reverse transcriptase open-in-new

Telomerase reverse transcriptase