Families
Members of the epithelial Na+ channel (ENaC) family fall into four subfamilies, termed alpha, beta, gamma and delta. The proteins exhibit the same apparent topology, each with two transmembrane (TM) spanning segments, separated by a large extracellular loop. In most ENaC proteins studied to date, the extracellular domains are highly conserved and contain numerous cysteine residues, with flanking C-terminal amphipathic TM regions, postulated to contribute to the formation of the hydrophilic pores of the oligomeric channel protein complexes. It is thought that the well-conserved extracellular domains serve as receptors to control the activities of the channels.
Vertebrate ENaC proteins are similar to degenerins of Caenorhabditis elegans: deg-1, del-1, mec-4, mec-10 and unc-8. These proteins can be mutated to cause neuronal degradation, and are also thought to form sodium channels.
Read more about this topic: Epithelial Sodium Channel
Famous quotes containing the word families:
“Nostalgia is one of the great enemies of clear thinking about the family. The disruption of families in the nineteenth century through death, separation, and other convulsions of an industrializing economy was much more catastrophic than we imagine.”
—Joseph Featherstone (20th century)
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—Stephanie Coontz (20th century)
“Accidents will occur in the best-regulated families; and in families not regulated by that pervading influence which sanctifies while it enhances ... in short, by the influence of Woman, in the lofty character of Wife, they may be expected with confidence, and must be borne with philosophy.”
—Charles Dickens (1812–1870)