Figure 3.

V_j gating of AF-linked mutant GJs. (A) Dual whole-cell patch clamp was used to measure I_js in N2A cell pairs expressing Cx40, K107R, L223M, Q236H, or I257L in response to a series of V_j pulses as indicated. Superimposed I_js for each mutant is shown; (B) normalized steady state junctional conductance, G_j,ss, of the Cx40 mutants (black filled circles) and wildtype Cx40 (grey open circles) were plotted at different V_js. The G_j,ss–V_j plot of each mutant was fitted with a two-state Boltzmann equation at each V_j polarity (smooth black lines). Boltzmann fittings of G_j,ss–V_j plot of wildtype Cx40 (smooth grey dashed lines) were obtained and superimposed on each plot for comparison. The number of cell pairs is indicated.