Protein / target
Potassium voltage-gated channel subfamily KQT member 3
Protein at a glance
Biological role
Voltage-gated monoatomic cation channel
Strongest disease association
Genetic Diseases, Inborn
Therapeutic position
Established drug target
Derived from structured UniProt, Open Targets and literature data on this page.
Protein profile
Canonical identity and biological annotation from UniProt.
Function overview
Pore-forming subunit of the voltage-gated potassium (Kv) M-channel which is responsible for the M-current, a key controller of neuronal excitability.
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Pore-forming subunit of the voltage-gated potassium (Kv) M-channel which is responsible for the M-current, a key controller of neuronal excitability (PubMed:16319223, PubMed:27564677, PubMed:28793216, PubMed:9872318). M-channel is composed of pore-forming subunits KCNQ2 and KCNQ3 assembled as heterotetramers (PubMed:14534157, PubMed:16319223, PubMed:27564677, PubMed:9872318). The native M-current has a slowly activating and deactivating potassium conductance which plays a critical role in determining the subthreshold electrical excitability of neurons as well as the responsiveness to synaptic inputs (PubMed:14534157, PubMed:16319223, PubMed:28793216). M-channel is selectively permeable in vitro to other cations besides potassium, in decreasing order of affinity K(+) > Rb(+) > Cs(+) > Na(+) (PubMed:28793216). M-channel association with SLC5A3/SMIT1 alters channel ion selectivity, increasing Na(+) and Cs(+) permeation relative to K(+) (PubMed:28793216). Suppressed by activation of M1 muscarinic acetylcholine receptors (PubMed:10713961). KCNQ3 also associates with KCNQ5 to form a functional channel in vitro and may also contribute to the M-current in brain (PubMed:11159685)
Subcellular location
Domains and Gene Ontology detail (11)Hide
Gene Ontology
- Caxon initial segment
- Ccell surface
- Cnode of Ranvier
- Cplasma membrane
- Csynapse
- Cvoltage-gated potassium channel complex
- Fcalmodulin binding
- Fvoltage-gated monoatomic cation channel activity
- Fvoltage-gated potassium channel activity
- Pchemical synaptic transmission
- Ppotassium ion transmembrane transport
Biological roles
What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.
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Synaptic signalling
- ·synapse
- ·chemical synaptic transmission
Ion channel gating
- ·voltage-gated monoatomic cation channel activity
- ·potassium ion transmembrane transport
Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.
Approved medicines with mapped indications
Approved therapies targeting this protein, grouped by what they are approved to treat — the disease-first view of the medicines below. Relationships come from the canonical approved-indication graph (ChEMBL phase-4), the same source as the drug cards.
6 medicines meet Open Targets' target-level approved-medicine definition; the 3 shown here are those on this page with a canonical approved disease indication in the graph. Approved indications from ChEMBL (phase-4), via the canonical drug→disease graph.
Drugs targeting this protein
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.
Voltage-gated potassium channel blocker
Indicated for Lambert-Eaton Myasthenic Syndrome
ChEMBL mechanism, action type, target identity and approved indications. Open Targets clinical status.
Translational evidence
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 KCNQ3
Gene-level evidence surfaced through the gene KCNQ3that 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.
View evidence synthesis (2)Hide
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.
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Drug development
8 compounds recorded · 6 approved · 2 in clinical development
View all recorded compounds (8)Hide
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 molecules — Strong
Antibodies — Emerging
Protein degraders — Emerging
View underlying tractability evidence (8)Hide
Raw Open Targets tractability assessment buckets, by modality.
Clinical trials
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.
View all trials (26)Hide
ClinicalTrials.gov via the drug-target graph.
What's happening now
Recent therapeutic activity around this target — regulatory actions, clinical trials and safety signals for 2 drugs that target 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.
- Supplemental approval
Supplemental approval: DALFAMPRIDINE (ANDA210158)
- Label change
Label change: DALFAMPRIDINE (ANDA210158)
- Label change
Label change: DALFAMPRIDINE (ANDA210158)
- Label change
Label change: DALFAMPRIDINE (ANDA210158)
- Regulatory approval
Approval: DALFAMPRIDINE (ANDA210158)
- Regulatory approval
Approval: Firdapse (previously Zenas) (EMA)
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.