Sodium channel epithelial 1 subunit beta (ENaC β (or SCNN1B))

Sodium channel epithelial 1 subunit beta (ENaC β, encoded by the SCNN1B gene) is one of three essential pore-forming subunits (α, β, γ) that assemble to form the epithelial sodium channel (ENaC), a non-voltage-gated, amiloride-sensitive sodium ion channel. ENaC is primarily expressed in the apical membrane of epithelial cells in tissues such as kidney, lung, colon, and sweat glands, where it mediates the electrogenic transport of sodium ions from the extracellular fluid into cells, a process crucial for maintaining sodium balance, extracellular fluid volume, airway surface liquid, and blood pressure. The β subunit plays a structural and regulatory role in functional channel assembly, gating, and trafficking. Mutations in SCNN1B lead to diseases of sodium imbalance, most notably Liddle syndrome and pseudohypoaldosteronism type 1, with significant consequences for blood pressure and fluid homeostasis. Amiloride and its analogs are direct blockers of ENaC and are used clinically as potassium-sparing diuretics for conditions of sodium and fluid overload. The channel is regulated by multiple hormones, including aldosterone and vasopressin, and is implicated in both renal and pulmonary diseases as well as in the perception of salty taste[2][4][5][8].

Other names

Epithelial sodium channel subunit betaENaC beta subunitSCNN1BAmiloride-sensitive sodium channel beta subunit

Direct channel inhibition (e.g., amiloride blocks sodium influx through ENaC)\n- Modulation by aldosterone (increases channel expression/activity)\n- Indirect reduction of channel activity through mineralocorticoid receptor antagonism