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,[2] 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.[3]
The apical membranes of many tight epithelia contain sodium channels that are characterized primarily by their high affinity for the diuretic blocker amiloride.[2][4][5][6] These channels mediate the first step of active sodium reabsorption essential for the maintenance of body salt and water homeostasis.[4] 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.
^Noreng S, Bharadwaj A, Posert R, Yoshioka C, Baconguis I (September 2018). "Structure of the human epithelial sodium channel by cryo-electron microscopy". eLife. 7: e39340. doi:10.7554/eLife.39340. PMC 6197857. PMID 30251954.
^ abHanukoglu I, Hanukoglu A (April 2016). "Epithelial sodium channel (ENaC) family: Phylogeny, structure-function, tissue distribution, and associated inherited diseases". Gene. 579 (2): 95–132. doi:10.1016/j.gene.2015.12.061. PMC 4756657. PMID 26772908.
^Shekdar K, Langer J, Venkatachalan S, Schmid L, Anobile J, Shah P, et al. (March 2021). "Cell engineering method using fluorogenic oligonucleotide signaling probes and flow cytometry". Biotechnology Letters. 43 (5): 949–958. doi:10.1007/s10529-021-03101-5. PMC 7937778. PMID 33683511.
^Waldmann R, Champigny G, Bassilana F, Voilley N, Lazdunski M (November 1995). "Molecular cloning and functional expression of a novel amiloride-sensitive Na+ channel". The Journal of Biological Chemistry. 270 (46): 27411–4. doi:10.1074/jbc.270.46.27411. PMID 7499195.
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Sodiumchannels are integral membrane proteins that form ion channels, conducting sodium ions (Na+) through a cell's membrane. They belong to the superfamily...
Sodiumchannel blockers are drugs which impair the conduction of sodium ions (Na+) through sodiumchannels. The following naturally-produced substances...
protein subunits of the Epithelialsodium (Na+) channel (ENaC). These studies also helped establish that ENaC is the principal channel involved in blood volume...
cells, preventing sodium reabsorption. Similar agents are eplerenone and potassium canreonate.[citation needed] Epithelialsodiumchannel blockers: amiloride...
problems, diabetes, and those who are older. Amiloride blocks the epithelialsodiumchannel (ENaC) in the late distal tubule, connecting tubule, and collecting...
mutations in the genes SCNN1A, SCNN1B, and SCNN1G that code for the epithelialsodiumchannel subunits, α, β, and γ, respectively. Hyperchloremic acidosis...
(Epithelialsodiumchannel) is located along the entire length of the cilia. In sweat glands, defective CFTR results in reduced transport of sodium chloride...
for greater absorption and secretion. It has been shown that epithelialsodiumchannel ENaC that allows the flow of Na+ ions into the cell is localized...
Sharma S, Kleyman T, Hanukoglu A (January 2017). "Expression of epithelialsodiumchannel (ENaC) and CFTR in the human epidermis and epidermal appendages"...
Spermatogenesis Sharma S, Hanukoglu A, Hanukoglu I (2018). "Localization of epithelialsodiumchannel (ENaC) and CFTR in the germinal epithelium of the testis, Sertoli...
of NEDD4-2 include the epithelialsodiumchannel (ENaC), the Na+-Cl- co-transporter (NCC), and the voltage gated sodiumchannels (Navs), although additional...
ISBN 978-0-7637-3905-8. Hanukoglu I, Hanukoglu A (April 2016). "Epithelialsodiumchannel (ENaC) family: Phylogeny, structure-function, tissue distribution...
either channels or carriers (a.k.a. transporters, or permeases). Examples of channel/carrier proteins include the GLUT 1 uniporter, sodiumchannels, and...
blocks the epithelialsodiumchannel (ENaC) on the lumen side of the kidney collecting tubule.: 127 Other diuretics cause a decrease in the sodium concentration...
are re-absorbed into tissue by epithelialsodiumchannels (ENaC) that are located on the apical membrane of epithelial cells that form the duct (see Fig...
selectively (excluding, most notably, sodium despite the sub-angstrom difference in ionic radius). Biologically, these channels act to set or reset the resting...
The SCNN1D gene encodes for the δ (delta) subunit of the epithelialsodiumchannel ENaC in vertebrates. ENaC is assembled as a heterotrimer composed of...
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