| A 14aa Peptide sequence near the N-terminus of rat ENAC g (1) was selected for antibody production. The peptide was coupled to KLH. Tissue acidosis (decrease in pH below the physiological level) that occurs in ischemia, tissue damage or inflammation is accompanied by pain. At the molecular level, H+-gated cation channels are activated by low pH in nociceptive neurons. H+-gated cation channels, members of the NaC/DEG superfamily of Na channels that include amiloride-sensitive epithelial Na+ channel proteins (alpha, beta, and gamma, and delta-ENaC subunits), are expressed in epithelia of the vertebrate kidney, colon, lung, tongue, and brain. The ENaC subunits may form heterotrimeric active Na channel. ENaCs are involved in Na and water readsorption, and salty taste transduction) of vertebrate colon, lung, kidney and tongue. The superfamily of DEG/NaC proteins are characterized by intracellular N and C-termini, two TM domains, and a large extracellular loop. ENaC-beta subunit (mouse/rat 638 aa, human 640 aa), ENaC-gamma subunit (mouse 655 aa, rat 650 aa, and human 649 aa) are expressed in lung, kidney, colon and other tissues. ENaC-b from various species are ~80% identical, and only ~30% similarity with the ENaC-alpha ENaC-delta (human 638 aa) is expressed mainly in brain, pancreas, testis, and ovary. It is 27-30% homologous with the other ENaCs. It can associate with b, and g ENaC to form a functional channel. |
