The epithelial sodium channel (ENaC) plays a key role in salt and water homeostasis in tetrapod vertebrates. There are four ENaC subunits (α, β, γ and δ) which form heterotrimeric αβγ- or δβγ-ENaC assemblies. ENaC activity is tightly coupled to proteolytic processing of ENaC subunits, but this effect is specific to ENaC subunit assembly and mechanistically not completely understood. Guinea pig αβγ- or δβγ-ENaCs were heterologo...

The cystic fibrosis transmembrane conductance regulator (CFTR) anion channel and the epithelial Na + channel (ENaC) play essential roles in transepithelial ion and fluid transport in numerous epithelial tissues. Inhibitors of both channels have been important tools for defining their physiological role in vitro. However, two commonly used CFTR inhibitors, CFTR inh -172 and GlyH-101, also inhibit non-CFTR anion channels, indica...