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. Plays an essential role in electrolyte and blood pressure homeostasis, but also in airway surface liquid homeostasis, which is important for proper clearance of mucus. Controls the reabsorption of sodium in kidney, colon, lung and sweat glands. Also plays a role in taste perception. Activated by WNK1, WNK2, WNK3 and WNK4. Heterotrimer containing an alpha/SCNN1A, a beta/SCNN1B and a gamma/SCNN1G subunit. An additional delta/SCNN1D subunit exists only in some organisms and can replace the alpha/SCNN1A subunit to form an alternative channel with specific properties (By similarity). Interacts with NEDD4 (via WW domains) (PubMed:11244092, PubMed:15123669). Interacts with NEDD4L (via WW domains) (PubMed:11244092, PubMed:12424229, PubMed:15123669). Interacts with WWP1 (via WW domains). Interacts with WWP2 (via WW domains). Interacts with the full-length immature form of PCSK9 (pro-PCSK9) (By similarity). Interacts (N-glycosylated) with BPIFA1; the interaction is direct and inhibits the proteolytic processing of SCNN1A and SCNN1G and the activation of ENaC (By similarity). Apical membrane of epithelial cells. Lung and kidney. N-glycosylated. N-glycosylation is required for interaction with BPIFA1. Phosphorylated on serine and threonine residues. Aldosterone and insulin increase the basal level of phosphorylation. Belongs to the amiloride-sensitive sodium channel (TC 1.A.6) family. SCNN1B subfamily.