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Protein / target

Telomerase reverse transcriptase

Encoded byTERTO14746Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
2
Approved medicines
Open Targets target-level
9
Clinical trials
Small-molecule tractable
Druggability
High-Quality Ligand

Protein at a glance

Biological role

Template-free RNA nucleotidyltransferase

Strongest disease association

Autosomal recessive dyskeratosis congenita 4

Via encoding gene TERT · Genetic literature evidence · score 0.96

Therapeutic position

Established drug target

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 overview

Telomerase is a ribonucleoprotein enzyme essential for the replication of chromosome termini in most eukaryotes.

View complete UniProt function annotation

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.

Cell migrationGOCell-cycle regulationGOTranscriptional regulationGOApoptosis & cell deathGO
View supporting evidence

Cell migration

  • ·positive regulation of vascular associated smooth muscle cell migration

Cell-cycle regulation

  • ·positive regulation of G1/S transition of mitotic cell cycle

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
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

How approved and investigational drugs engage this protein — mechanism and action type, direct vs complex targeting, and how broadly each acts across other targets. A drug-first view (the section above groups the approved ones disease-first); direct binders with few recorded targets are listed first.

imetelstat
Narrow target profileApprovedInhibitor

Telomerase reverse transcriptase inhibitor

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

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

Translational evidence

Open Targets 26

Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.

Strongest disease associations · via encoding gene TERT

Gene-level evidence surfaced through the gene TERTthat encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.

pulmonary fibrosis and/or bone marrow failure, Telomere-related, 1
0.95Well supported

Genetic evidence dominant · Open Targets 0.81

Dyskeratosis congenita, autosomal dominant 2
0.93Well supported

Genetic evidence dominant · Open Targets 0.86

Idiopathic Pulmonary Fibrosis
0.88Well supported

Genetic evidence dominant · Open Targets 0.72

Leukemia, Myeloid, Acute
0.88Well supported

Genetic evidence dominant · Open Targets 0.71

Anemia, Aplastic
0.87Well supported

Genetic evidence dominant · Open Targets 0.71

View evidence synthesis (5)
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

Leukemia, Myeloid, AcuteWell 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

Anemia, AplasticWell 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 per-type scores above show the calculation.

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
Leukemia, Myeloid, Acute0.71
Autosomal recessive dyskeratosis congenita 40.71
Anemia, Aplastic0.71
Melanoma, cutaneous malignant, susceptibility to, 90.65
Lung Diseases, Interstitial0.64
Pulmonary Fibrosis0.64

Drug development

2 compounds recorded · 2 approved

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines. Distinct from the 1 drug that targets this protein in Forefront's canonical graph: these count different sets and are not a subset relation.

View all recorded compounds (2)
IMETELSTATApproval
IMETELSTAT SODIUMApproval

Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.

Tractability

Small moleculesEmerging

Feasibility evidence (high-quality ligand and druggable family) — no clinical-stage drug of this modality recorded.

AntibodiesEmerging

Feasibility evidence (go cc med conf) — no clinical-stage drug of this modality recorded.

Protein degradersEmerging

Feasibility evidence (uniprot ubiquitination and small molecule binder) — no clinical-stage drug of this modality recorded.

Other modalitiesStrong

Advanced Clinical support this modality.

View underlying tractability evidence (6)
SM · High-Quality LigandSM · Druggable FamilyAB · GO CC med confPR · UniProt UbiquitinationPR · Small Molecule BinderOC · Advanced Clinical

Raw Open Targets tractability assessment buckets, by modality.

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. Ranked by active status, then clinical phase and recency, and spread across the targeting drugs.

ClinicalTrials.gov via the drug-target graph.

What's happening now

2

Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for a drug that targets this protein, plus publications where such a drug is a genuine subject. Every item is reached indirectly through the drug, not the protein itself; incidental mentions (a paper that merely measures a drug) and press items are excluded.

  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.