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:
“We now recognize that abuse and neglect may be as frequent in nuclear families as love, protection, and commitment are in nonnuclear families.”
—David Elkind (20th century)
“Children from humble families must be taught how to command just as other children must be taught how to obey.”
—Friedrich Nietzsche (1844–1900)
“The brotherhood of men does not imply their equality. Families have their fools and their men of genius, their black sheep and their saints, their worldly successes and their worldly failures. A man should treat his brothers lovingly and with justice, according to the deserts of each. But the deserts of every brother are not the same.”
—Aldous Huxley (1894–1963)