Fig. 5.

ATP is not required for VSD movement. (A) VCF recordings of the WT and ATP-binding disruptive mutant KCNQ1 channels. Whole-cell current (Upper) and fluorescence signal (Lower) of WT (black), W379S (red), and R380S/R397W (green) in response to increasing voltages. (B) Superimposed fluorescence signal (Left) of WT (black), W379S (red), and R380S/R397W (green) in response to a series of voltage pulses with increasing voltages. The currents activation time constants in response to voltages (Right). (C) Steady-state fluorescence changes vs. voltage (F–V).