FIGURE 3.

KDC1-KAT1 heterodimeric channels display the same zinc sensitivity as KDC1:KAT1 heteromultimeric channel. (A) Typical ionic currents recorded in oocytes before (control) and after (recovery) the application of ZnCl₂ to the bath solution. Like in KDC1:KAT1 channels current was enhanced (∼1.6-fold) in the presence of 1 mM of Zn²⁺. Applied transmembrane potentials to −150 mV. (B) Zn²⁺ dose-response curves for the dimeric (KDC1-KAT1) and heteromeric (KDC1:KAT1) channels. Data were obtained from at least three different experiments. I_Zn/I_control represents the steady state of the ionic current recorded in the presence of Zn²⁺ with respect to the control (i.e., Zn²⁺ = 0). (C) Comparison of the open probability in presence of 1 mM Zn²⁺. Continuous lines are the best fit of the open probability and gave the following values: KDC1-KAT1 (V_1/2 = −166 mV, z = 1.8, n = 4) and KDC1:KAT1 (V_1/2 = −163 mV, z = 1.9, n = 4). Standard ionic solution, pH 5.6.