Amiloride-sensitive sodium channels (SCNNs, aka ENaCs, epithelial Na+ channels, non voltage-gated sodium channels) belong to the epithelial Na+ channel/degenerin (ENaC/DEG) protein family and mediate the transport of Na+ (and associated water) through the apical membrane of epithelial cells in kidney, colon and lungs. This makes SCNNs important determinants of systemic blood pressure. The physiological activator for SCNNs is unknown but as they belong in the same family as acid-sensitive ion channels (ASICs, which are mediated by protons), these may also be the activating ligands for SCNNs. SCNNs are probable heterotrimers comprising an alpha (or interchangeable delta subunit), beta and gamma subunit (Horisberger 1998).
ligand-gated sodium channel activity of SCNN channels [plasma membrane]