Protein / target

Telomerase reverse transcriptase

TERTO14746Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
2
Approved medicines
9
Clinical trials
Small-molecule tractable
Druggability
High-Quality Ligand

Protein at a glance

Biological role

Template-free RNA nucleotidyltransferase activity

Primary system

Cardiovascular system

Strongest disease association

autosomal recessive dyskeratosis congenita 4

Genetic literature evidence · score 0.96

Therapeutic maturity

Clinically validated target

2 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · High-Quality Ligand

Clinical development

2 approved

9 linked trials

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function

Telomerase is a ribonucleoprotein enzyme essential for the replication of chromosome termini in most eukaryotes. Active in progenitor and cancer cells. Inactive, or very low activity, in normal somatic cells. Catalytic component of the teleromerase holoenzyme complex whose main activity is the elongation of telomeres by acting as a reverse transcriptase that adds simple sequence repeats to chromosome ends by copying a template sequence within the RNA component of the enzyme. Catalyzes the RNA-dependent extension of 3'-chromosomal termini with the 6-nucleotide telomeric repeat unit, 5'-TTAGGG-3'. The catalytic cycle involves primer binding, primer extension and release of product once the template boundary has been reached or nascent product translocation followed by further extension. More active on substrates containing 2 or 3 telomeric repeats. Telomerase activity is regulated by a number of factors including telomerase complex-associated proteins, chaperones and polypeptide modifiers. Modulates Wnt signaling. Plays important roles in aging and antiapoptosis

Subcellular location

Nucleus, nucleolusNucleus, nucleoplasmNucleusChromosome, telomereCytoplasmNucleus, PML body
Domains and Gene Ontology detail (60)

Domains & features

Reverse transcriptase

Gene Ontology

  • Cchromosome, telomeric region
  • Ccytosol
  • Cmitochondrial nucleoid
  • Cnuclear speck
  • Cnuclear telomere cap complex
  • Cnucleolus
  • Cnucleoplasm
  • Cnucleus
  • Cplasma membrane
  • CPML body
  • CRNA-directed RNA polymerase complex
  • Ctelomerase catalytic core complex

1132 aa · 127 kDa · 4 isoforms

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

Transcriptional regulationGOApoptosis & cell deathGOMetabolic enzyme activityGO
View supporting evidence

Transcriptional regulation

  • ·transcription coactivator binding
  • ·positive regulation of miRNA transcription
  • ·RNA-templated transcription
  • ·siRNA transcription

Apoptosis & cell death

  • ·negative regulation of endothelial cell apoptotic process
  • ·negative regulation of neuron apoptotic process

Metabolic enzyme activity

  • ·template-free RNA nucleotidyltransferase activity
View underlying pathways (3)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

NHP2NOP10WRAP53TEP1DKC1HSP90A…SULT1E1CTNNB1RUVBL2POT1TERT

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Drugs targeting this protein

1

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

imetelstat
Narrow target profileApprovedInhibitor

Telomerase reverse transcriptase inhibitor

Appears in clinical studies involving anemia, myelodysplastic syndrome, neoplasm, myelofibrosis

Direct interaction with this protein · Only this protein recorded as a target

ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

autosomal recessive dyskeratosis congenita 40.96

Genetic literature · overall 0.71

pulmonary fibrosis and/or bone marrow failure, Telomere-related, 10.95

Genetic · overall 0.81

dyskeratosis congenita, autosomal dominant 20.93

Genetic · overall 0.86

acute myeloid leukemia0.91

Genetic literature · overall 0.71

dyskeratosis congenita0.91

Genetic literature · overall 0.80

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

idiopathic pulmonary fibrosis0.72

Genetic

aplastic anemia0.71

Genetic

melanoma, cutaneous malignant, susceptibility to, 90.65

Genetic literature

interstitial lung disease0.64

Genetic

pulmonary fibrosis0.64

Literature

Show all associations
dyskeratosis congenita, autosomal dominant 20.86
pulmonary fibrosis and/or bone marrow failure, Telomere-related, 10.81
dyskeratosis congenita0.80
idiopathic pulmonary fibrosis0.72
acute myeloid leukemia0.71
autosomal recessive dyskeratosis congenita 40.71
aplastic anemia0.71
melanoma, cutaneous malignant, susceptibility to, 90.65
interstitial lung disease0.64
pulmonary fibrosis0.64

Open Targets ranks 1,712 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 2 total

IMETELSTATApproval

anemia · myelodysplastic syndrome · neoplasm

IMETELSTAT SODIUMApproval

anemia · myelodysplastic syndrome · breast cancer

Tractability

SM · High-Quality LigandSM · Druggable FamilyAB · GO CC med confPR · UniProt UbiquitinationPR · Small Molecule BinderOC · Advanced Clinical

Clinical trials

9

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein.

ClinicalTrials.gov via the drug-target graph.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

pulmonary fibrosis and/or bone marrow failure, Telomere-related, 1Well supported
0.95
agreement 0.831.00
Genetic100%Genetic literaturedup

Open Targets aggregate 0.81 · 1 independent evidence family · 1 not counted as duplicate

dyskeratosis congenita, autosomal dominant 2Well supported
0.93
agreement 0.811.00
Genetic100%Genetic literaturedup

Open Targets aggregate 0.86 · 1 independent evidence family · 1 not counted as duplicate

idiopathic pulmonary fibrosisWell supported
0.88
agreement 0.741.00
Genetic89%Literature11%

Open Targets aggregate 0.72 · 2 independent evidence families

acute myeloid leukemiaWell supported
0.88
agreement 0.790.97
Genetic60%Somatic mutation23%Literature10%Clinical8%Genetic literaturedup

Open Targets aggregate 0.71 · 4 independent evidence families · 1 not counted as duplicate

aplastic anemiaWell supported
0.87
agreement 0.760.98
Genetic95%Literature4%Somatic mutation1%Genetic literaturedup

Open Targets aggregate 0.71 · 3 independent evidence families · 1 not counted as duplicate

This ranking differs from Open Targets' own: re-weighting moves genetically-evidenced diseases above more heavily co-mentioned ones. The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the underlying per-type scores are shown above so the calculation can be checked.

What's happening now

2

Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.

  1. Regulatory approval2025-03-07

    Approval: Rytelo (EMA)

    ema · regulatory · ema · via imetelstat

  2. New publication2023-10-30
    Imetelstat-mediated alterations in fatty acid metabolism to induce ferroptosis as a therapeutic strategy for acute myeloid leukemia.

    Nature cancer · 2024 · 74 citations · Europe PMC · via imetelstat

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.