SCN3B
Sodium Voltage-Gated Channel Beta Subunit 3
Gene Information Card
| Symbol | SCN3B |
|---|---|
| Full Name | Sodium Voltage-Gated Channel Beta Subunit 3 |
| Gene Type | protein-coding |
| Chromosomal Location | 11q24.1 |
| NCBI Gene ID | 55800 ncbi.nlm.nih.gov/gene/55800 |
| Ensembl ID | ENSG00000166257 |
| UniProt ID | Q9NY72 |
| OMIM ID | 608214 |
| HGNC ID | 10594 |
| Aliases | HSA243396, SCN3B, UNQ302/PRO343 |
Description
SCN3B encodes the beta-3 subunit of voltage-gated sodium channels, which modulates channel gating, kinetics, and cell surface expression. It is primarily expressed in cardiac muscle, brain, and dorsal root ganglia. Mutations in SCN3B are associated with cardiac arrhythmias such as Brugada syndrome and atrial fibrillation, as well as epilepsy.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Brugada syndrome 7 | Loss-of-function mutations reduce sodium current (INa), leading to altered cardiac repolarization | ClinVar, OMIM |
| Atrial fibrillation, familial, 16 | Missense mutations impair channel trafficking and current density | ClinVar, OMIM |
| Epilepsy, early-onset, with or without intellectual disability | Disrupted sodium channel function in neurons | ClinVar |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Heart | 12.5 | Medium |
| Brain | 8.3 | Low |
| Skeletal muscle | 4.1 | Low |
| Testis | 2.0 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| Cardiomyocytes | 15.2 | High expression |
| SH-SY5Y (neuroblastoma) | 6.8 | Moderate |
| HEK 293 | 0.5 | Low |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.448G>A (p.Gly150Arg) | Missense | Rare | Reduced sodium current; associated with Brugada syndrome |
| c.544C>T (p.Arg182Trp) | Missense | Rare | Impaired trafficking; linked to atrial fibrillation |
| c.1A>G (p.Met1Val) | Start loss | Very rare | Loss of protein expression; epilepsy phenotype |
Mutation functional classification
Loss of Function (LOF)
Most SCN3B mutations reduce sodium current (INa) by impairing channel trafficking or gating, leading to Brugada syndrome and atrial fibrillation.
Gain of Function (GOF)
No gain-of-function mutations reported in SCN3B.
Dominant Negative (DN)
Some missense variants (e.g., p.Gly150Arg) exert dominant-negative effects on wild-type beta subunits, further reducing sodium current.
View complete mutation data：
Gene Ontology (GO)
Pathways
• Voltage-gated sodium channel complex (Reactome: R-HSA-5576892)
• Cardiac conduction (Reactome: R-HSA-5576891)
• Neuronal system (Reactome: R-HSA-112316)
Protein Summary
SCN3B encodes a 215-amino acid type I transmembrane protein with an extracellular immunoglobulin-like domain. It associates with the pore-forming alpha subunit (e.g., SCN5A) to modulate channel gating, voltage dependence, and cell surface expression. The beta-3 subunit is critical for normal cardiac and neuronal excitability.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SCN3B Knockout HEK293 Cell Line | EDJ-KQ15189 | Human | 55800 | Details Get a Quote |
| SCN3B Knockout HeLa Cell Line | EDJ-KQ56633 | Human | 55800 | Details Get a Quote |
| SCN3B Knockout A-549 Cell Line | EDJ-KQ65138 | Human | 55800 | Details Get a Quote |
| SCN3B Knockout HCT 116 Cell Line | EDJ-KQ73576 | Human | 55800 | Details Get a Quote |
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