Figure 3.

hENaC containing αG70S gates in a voltage-dependent manner with increased P_o at hyperpolarizing potentials. (A) Families of representative single-channel current traces for wild-type (top) and mutant (bottom) hENaC in outside-out patches stepped from 80 mV to −80 mV. The bath and pipette [Li⁺] were symmetrical for these experiments. Inward Na⁺ current is downward; C, closed state. (B) Single-channel I/V relations for wild-type (black squares) and αG70S (gray circles) hENaC in outside-out patches. Data were obtained from experiments identical to that in panel A; n ≥ 3 for each group. (C) Plot showing the ENaC P_o as a function of voltage for wild-type (black squares) and mutant channels containing the αG70S mutation (gray circles). Data were fit by the Boltzmann equation. Data were obtained from experiments identical to that in panel A; n ≥ 3 for each group.