Nav1.4 Sodium Channel is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
Nav1.4 (SCN4A) is a voltage-gated sodium channel specifically expressed in skeletal muscle. It is essential for muscle fiber depolarization and contraction.
This protein is involved in:
- Muscle contraction: Mediates action potentials in skeletal muscle
- Neuromuscular transmission: Converts motor endplate potentials to muscle action potentials
- Muscle excitability: Determines threshold for muscle activation
| Attribute |
Value |
| Protein Name |
Nav1.4 (SkM1) |
| Gene |
SCN4A |
| UniProt ID |
P15324 |
| PDB IDs |
6AGF, 7JX0 |
| Molecular Weight |
~260 kDa |
| Subcellular Localization |
Sarcolemma, T-tubules |
| Protein Family |
Voltage-gated sodium channel (NaV) family |
Nav1.4 is composed of:
- 4 Homologous Domains (DI-DIV): Each containing 6 transmembrane segments
- Voltage Sensor (S1-S4): Contains positively charged residues
- Pore Region (S5-S6): Forms ion selectivity filter
- Fast Inactivation Gate: Located between DIII and DIV
- β1 subunit association: Modulates channel properties
- Muscle Depolarization: Mediates rapid Na+ influx during action potential
- Excitation-Contraction Coupling: Initiates muscle contraction
- Force Generation: Enables rapid force development
- Muscle Fiber Types: Expressed in all skeletal muscle fiber types
- Mechanism: Gain-of-function mutations cause sustained depolarization
- Trigger: Exercise, potassium intake
- Treatment: Acetazolamide, dichlorphenamide
- Mechanism: Some mutations cause hyperexcitability
- Trigger: Carbohydrates, rest after exercise
- Cold sensitivity: Mutations cause temperature-dependent myotonia
- Mechanism: Impaired fast inactivation
- SCN4A channelopathies - Cannon SC, et al. Physiol Rev 2006 PMID:16818940
The study of Nav1.4 Sodium Channel has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.
- Gene expression and function in neuronal tissues. PubMed.
- Role in neuronal excitability and synaptic transmission. PubMed.
- Calcium channel dysfunction in neurological disorders. PubMed.
- Voltage-gated ion channels in neurodegeneration. PubMed.