Sodium channel subunit beta-3 (SCN3B)

Sodium channel subunit beta-3 (SCN3B) is a membrane protein encoded by the SCN3B gene and serves as an auxiliary regulatory subunit for voltage-gated sodium channels (Nav). These channels are crucial for the initiation and propagation of action potentials in excitable cells such as neurons and cardiac muscle. SCN3B modulates the gating kinetics, especially the inactivation behavior, of sodium channels, thereby influencing electrical signaling and conduction. Its unique extracellular Ig-like domain provides distinct adhesion properties and structural support. SCN3B plays vital roles in cardiac excitability and rhythm; mutations are linked to arrhythmic conditions including Brugada syndrome and familial atrial fibrillation. While no approved drugs directly target SCN3B, it is a key modulator within the sodium channel complex, with potential therapeutic implications for cardiovascular and neurodegenerative diseases. SCN3B also participates in cellular stress signaling, acting via p53-dependent pathways to influence apoptosis and cell proliferation in a context-dependent manner.

Other names

Sodium channel regulatory subunit beta-3SCN3BKIAA1158SCNB3ATFB16BRGDA7HSA243396sodium channel, voltage-gated, type III, beta subunitvoltage-gated sodium channel beta-3 subunit

Modulation of Nav channel function via alteration of gating and inactivation kinetics (when part of the sodium channel complex); Indirectly affected by sodium channel blockers (e.g., antiarrhythmic agents) acting at the channel level, not specifically at beta-3 subunit