ENAC

The epithelial sodium channel (ENaC), (also known as amiloride-sensitive sodium channel) is a membrane-bound ion channel that is selectively permeable to sodium ions (Na+). It is assembled as a heterotrimer composed of three homologous subunits α or δ, β, and γ, These subunits are encoded by four genes: SCNN1A, SCNN1B, SCNN1G, and SCNN1D. The ENaC is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney's nephrons. In addition to being implicated in diseases where fluid balance across epithelial membranes is perturbed, including pulmonary edema, cystic fibrosis, COPD and COVID-19, proteolyzed forms of ENaC function as the human salt taste receptor.