Voltage-gated sodium channel (Nav1) (Nav1)

Voltage-gated sodium channels (Nav1) are essential transmembrane proteins that mediate the rapid influx of sodium ions across the cell membrane, a process fundamental to the initiation and propagation of action potentials in excitable tissues [6, 9]. The Nav1 family comprises nine distinct alpha-subunit isoforms (Nav1.1 through Nav1.9), which are expressed in a tissue-specific manner across the central and peripheral nervous systems, as well as in skeletal and cardiac muscle [7, 13]. These channels play a pivotal role in physiological processes such as sensory perception, motor control, and cardiac rhythmicity [5, 12]. Dysregulation or mutations in the genes encoding these subunits (SCN1A-SCN11A) are associated with a wide spectrum of diseases, known as channelopathies, including various forms of epilepsy, chronic pain syndromes, and life-threatening cardiac arrhythmias [5, 9]. Pharmacologically, Nav1 channels are targeted by a diverse array of drugs, including local anesthetics, antiarrhythmics, and anticonvulsants, which typically function by blocking the ion-conducting pore in a state-dependent manner [7, 8]. Recent evidence also suggests that Nav1 channels are expressed in non-excitable cells, such as cancer cells, where they may contribute to invasive and metastatic behavior [1, 10]. The structural complexity of these channels, involving four homologous domains and auxiliary beta subunits, allows for fine-tuned regulation of electrical signaling [6, 11]. Therapeutic development continues to focus on subtype-selective inhibitors to minimize off-target effects, particularly for the treatment of chronic pain and epilepsy [2, 8].

Other names

VGSCSodium channel alpha subunitNaVVoltage-dependent sodium channel

Drugs targeting Nav1 channels typically act through state-dependent blockade of the ion-conducting pore [13]. They primarily bind to a conserved receptor site located in the S6 segment of domain IV, which stabilizes the channel in its non-conducting inactivated state, thereby inhibiting the influx of sodium ions and preventing membrane depolarization [7, 9].