Figure 2.

Knockdown of DHHC7 decreases macroscopic ClC-Ka/barttin currents. A, voltage protocol and representative whole-cell current recordings from HEK293T cells expressing hClC-Ka/barttin channels under varying conditions of DHHC7 expression: control, presence of endogenous DHHC7; DHHC7, overexpression of DHHC7; shRNA, partial knockdown of DHHC7 (shRNA against a scrambled target sequence (scr) served as control). B, voltage dependence of hClC-Ka/barttin currents under varying conditions of DHHC7 expression. C, comparison of mean current amplitudes at 105 mV. D–G, stationary noise analysis of hClC-Ka/barttin currents. D, representative plot of the current variance σ², normalized to the product of the mean current amplitude (I) and the electrical driving force (V-Vrev), versus the macroscopic conductance (I/(V-Vrev)). A linear regression provides the single channel conductance (gCl) as y axis intercept and the number of active channels as inverse slope. E, mean values of single-channel conductance (gCl). F, voltage dependence of absolute open probabilities of hClC-Ka/barttin channels. G, mean values of V_mid, the voltage of half-maximal activation of hClC-Ka/barttin. B and F, all data are mean ± S.E.M. (error bars); C, E, G, all data are mean + S.D. (error bars); n is indicated in the bar graphs; ***, p ≤ 0.001, Student's t test.