The amiloride-sensitive epithelial Na+ channel (ENaC) family includes 4 members: ENaCα, β, γ and δ. The ENaC subunits have a conserved topology consisting of two membrane-spanning domains with intracellular N and C-termini and a large glycosylated extracellular region.nThe functional ENaC channel is a heteromer with a presumed stoichiometry of α2βγ while the δ subunit can substitute for the α subunit in some tissues. Interestingly, neither the β nor the γ subunits are capable of producing any current when expressed alone in heterologous systems, while in these systems the simultaneous presence of all three ENaC subunits will produce Na+ currents that resemble the endogenous channel.
