page_title: Epithelial sodium channel
hierarchical_section_title: Epithelial sodium channel
caption_attribution_description: English: ENaC with subunits colored (alpha blue, beta red, gamma magenta). Produced using PyMol from PDB entry 6BQN.
context_page_description: The epithelial sodium channel is a membrane-bound ion channel that is selectively permeable to the ions of sodium and that 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. It is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney's nephrons.
  The apical membranes of many tight epithelia contain sodium channels that are characterized primarily by their high affinity for the diuretic blocker amiloride. These channels mediate the first step of active sodium reabsorption essential for the maintenance of body salt and water homeostasis. In vertebrates, the channels control reabsorption of sodium in kidney, colon, lung and sweat glands; they also play a role in taste perception.
  The epithelial sodium channels are structurally and probably evolutionary related to P2X purinoreceptors, pain receptors that activate when they detect ATP.
context_section_description: The epithelial sodium channel (short: ENaC, also: amiloride-sensitive sodium channel) is a membrane-bound ion channel that is selectively permeable to the ions of sodium (Na⁺) and that 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. It is involved primarily in the reabsorption of sodium ions at the collecting ducts of the kidney's nephrons.
  The apical membranes of many tight epithelia contain sodium channels that are characterized primarily by their high affinity for the diuretic blocker amiloride. These channels mediate the first step of active sodium reabsorption essential for the maintenance of body salt and water homeostasis. In vertebrates, the channels control reabsorption of sodium in kidney, colon, lung and sweat glands; they also play a role in taste perception.
  The epithelial sodium channels are structurally and probably evolutionary related to P2X purinoreceptors, pain receptors that activate when they detect ATP.
caption: Structure of human ENaC.[1]
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