Fig. 2.

Proteolytic cleavage allows Na⁺ conduction through ENaC. ENaC is a heterotrimer consisting of α, β, and γ subunits that together form the functional channel. a In the absence of proteolysis, ENaC is uncleaved and cannot conduct Na⁺. b After proteolytic cleavage, the “inhibitory” tracts from the extracellular loops of the α and γ subunits are removed, possibly leading to a conformational change in the channel, which can now conduct Na⁺ (c)