Amiloride-Sensitive sodium Channel Subunit delta, Delta-NaCH, Epithelial Na(+) Channel Subunit delta, Delta-ENaC, ENaCD, Nonvoltage-Gated sodium Channel 1 Subunit delta, SCNED, SCNN1D, DNACH

The epithelial sodium channel (ENaC) is a member of the ENaC/DEG superfamily that is located on the apical surface of cells. ENaC mediates sodium reabsorption in kidney, distal colon, lung, ducts of exocrine glands and other organs. ENaC is formed by heteromultimerization of four homologous subunits, alpha, beta, y and delta. The most frequently formed heterotetramer consists of 2alpha, 1beta, and 1y subunit, but the alpha subunit can be replaced by a delta subunit. The alphaENaC gene maps to human chromosome 12p13, and expresses a glycosylated protein. Both the beta and yENaC genes map to human chromosome 16p12, and the yENaC transcript is detected as a glycosylated protein. The carboxy-terminus of all ENaC subunits contains Py motifs, which interact with the ubiquitin protein ligase, Nedd4, to regulate intracellular sodium concentrations. Gain-of-function mutations involving the Py motif cause Liddle’s syndrome, an autosomal dominant form of hypertension, resulting from excessive renal sodium absorption. Conversely, ENaC loss-of-function mutations result in pseudohypoaldosteronism type I, a disorder characterized by salt wasting and hypotension.