Sodium permeable non-voltage-sensitive ion channel inhibited by the diuretic amiloride. Mediates the electrodiffusion of the luminal sodium (and water, which follows osmotically) through the apical membrane of epithelial cells. Controls the reabsorption of sodium in kidney, colon, lung and sweat glands. Also plays a role in taste perception.
Involvement in disease
Defects in SCNN1G are a cause of Liddle syndrome (LIDDS) [MIM:177200]. It is an autosomal dominant disorder characterized by pseudoaldosteronism and hypertension associated with hypokalemic alkalosis. The disease is caused by constitutive activation of the renal epithelial sodium channel. Defects in SCNN1G are the cause of bronchiectasis with or without elevated sweat chloride type 3 (BESC3) [MIM:613071]. A debilitating respiratory disease characterized by chronic, abnormal dilatation of the bronchi and other cystic fibrosis-like symptoms in the absence of known causes of bronchiectasis (cystic fibrosis, autoimmune diseases, ciliary dyskinesia, common variable immunodeficiency, foreign body obstruction). Clinical features include sub-normal lung function, sinopulmonary infections, chronic productive cough, excessive sputum production, and elevated sweat chloride in some cases.
Belongs to the amiloride-sensitive sodium channel (TC 1.A.6) family. SCNN1G subfamily.
Phosphorylated on serine and threonine residues. Ubiquitinated; this targets individual subunits for endocytosis and proteasome-mediated degradation.
Apical cell membrane. Apical membrane of epithelial cells.