Voltage-gated sodium channel alpha subunit (Nav1.1, Nav1.2, Nav1.3, Nav1.4, Nav1.5, Nav1.8, Nav1.9) (Nav1.1–1.5, 1.8, 1.9)

Voltage-gated sodium channels (Nav) are critical transmembrane proteins that mediate the rapid influx of sodium ions required for the initiation and propagation of action potentials in excitable tissues [1]. This specific group of isoforms—Nav1.1, Nav1.2, Nav1.3, Nav1.4, Nav1.5, Nav1.8, and Nav1.9—plays diverse roles across the central nervous system, peripheral nervous system, heart, and skeletal muscle [2]. Nav1.1, Nav1.2, and Nav1.3 are primarily expressed in the brain and are major targets for antiepileptic drugs, while Nav1.4 and Nav1.5 are essential for skeletal muscle contraction and cardiac rhythm, respectively [3]. Nav1.8 and Nav1.9 are specialized for nociception in peripheral sensory neurons, making them key targets for pain management [4]. Dysregulation or genetic mutations in these channels lead to various channelopathies, including Dravet syndrome, Brugada syndrome, and chronic pain conditions [1, 3]. Pharmacological agents such as local anesthetics (e.g., lidocaine) and anti-arrhythmics (e.g., flecainide) typically act as pore blockers that stabilize the inactivated state of the channel to suppress hyperexcitability [2, 5]. A major challenge in drug development for this group is achieving isoform selectivity to avoid off-target effects, particularly cardiotoxicity associated with Nav1.5 inhibition [3, 6].

Other names

Sodium channel protein type 1 subunit alpha (SCN1A)Sodium channel protein type 2 subunit alpha (SCN2A)Sodium channel protein type 3 subunit alpha (SCN3A)Sodium channel protein type 4 subunit alpha (SCN4A)Sodium channel protein type 5 subunit alpha (SCN5A)Sodium channel protein type 10 subunit alpha (SCN10A)Sodium channel protein type 11 subunit alpha (SCN11A)Voltage-gated sodium channel type IVoltage-gated sodium channel type IIVoltage-gated sodium channel type IIISkM1H1PN3NaN

Drugs targeting these channels typically act as state-dependent blockers that bind to the local anesthetic receptor site within the alpha subunit's pore, stabilizing the inactivated state and reducing the influx of sodium ions during depolarization [3, 5].