KCNQ3
Potassium Voltage-Gated Channel Subfamily Q Member 3
Gene Information Card
| Symbol | KCNQ3 |
|---|---|
| Full Name | Potassium Voltage-Gated Channel Subfamily Q Member 3 |
| Gene Type | protein-coding |
| Chromosomal Location | 8q24.22 |
| NCBI Gene ID | 3786 ncbi.nlm.nih.gov/gene/3786 |
| Ensembl ID | ENSG00000184156 |
| UniProt ID | O43525 |
| OMIM ID | 602232 |
| HGNC ID | 6296 |
| Aliases | BFNC2, EBN2, Kv7.3, KQT-like 3 |
Description
KCNQ3 encodes the Kv7.3 subunit of the M-channel, a voltage-gated potassium channel that assembles with Kv7.2 (KCNQ2) to form the neuronal M-current. This current is a key regulator of neuronal excitability, controlling subthreshold electrical activity and limiting repetitive firing. Mutations in KCNQ3 are associated with benign familial neonatal seizures (BFNS) and other epileptic disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Benign Familial Neonatal Seizures (BFNS) | Loss-of-function mutations reduce M-current, increasing neuronal excitability and seizure susceptibility | ClinVar, OMIM |
| Epileptic Encephalopathy, Early Infantile | Severe loss-of-function or dominant-negative mutations impair M-current more profoundly | ClinVar, OMIM |
| Autism Spectrum Disorder (ASD) | Rare variants may alter neuronal excitability and network development | ClinVar, NCBI |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 24.5 | High |
| Cerebral Cortex | 28.1 | High |
| Hippocampus | 26.3 | High |
| Cerebellum | 18.7 | Medium |
| Spinal Cord | 12.4 | Medium |
| Heart | 1.2 | Low |
| Liver | 0.3 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 15.2 | High expression |
| U-87 MG (glioblastoma) | 8.7 | Medium expression |
| HEK 293 (embryonic kidney) | 0.5 | Low expression |
| HepG2 (hepatocellular carcinoma) | 0.2 | Not detected |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1040C>T (p.Thr347Met) | Missense | <0.01% | Reduces M-current amplitude; associated with BFNS |
| c.740G>A (p.Arg247His) | Missense | <0.01% | Impairs channel trafficking; causes epileptic encephalopathy |
| c.1129G>A (p.Gly377Ser) | Missense | <0.01% | Dominant-negative effect; severe epilepsy phenotype |
Mutation functional classification
Loss of Function (LOF)
Most common; reduces potassium conductance and M-current, leading to hyperexcitability.
Gain of Function (GOF)
Rare; not well-documented for KCNQ3.
Dominant Negative (DN)
Observed in some missense mutations (e.g., p.Gly377Ser) that impair wild-type subunit function.
View complete mutation data：
Gene Ontology (GO)
| • voltage-gated potassium channel activity | • delayed rectifier potassium channel activity |
| • plasma membrane | • neuronal cell body |
| • axon | • dendrite |
| • regulation of membrane potential | • nervous system development |
Pathways
• M-channel (KCNQ/Kv7) pathway
• Neuronal System
• Potassium Channels
Protein Summary
Kv7.3 is a 872-amino acid protein with six transmembrane domains (S1-S6), a pore loop between S5 and S6, and long cytoplasmic N- and C-termini. It forms heterotetramers with Kv7.2 to generate the M-current. The C-terminus contains a calmodulin-binding domain essential for channel assembly and modulation. Mutations in the pore region or C-terminus disrupt channel function.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| KCNQ3 Knockout HEK293 Cell Line | EDJ-KQ5057 | Human | 3786 | Details Get a Quote |
| KCNQ3 Knockout HeLa Cell Line | EDJ-KQ53727 | Human | 3786 | Details Get a Quote |
| KCNQ3 Knockout A-549 Cell Line | EDJ-KQ62204 | Human | 3786 | Details Get a Quote |
| KCNQ3 Knockout HCT 116 Cell Line | EDJ-KQ70691 | Human | 3786 | Details Get a Quote |
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