Kv1.1-1.1-1.2-1.2 and Kv1.2-1.1-1.2-1.1 yield functionally uniform K⁺ currents when expressed in HEK-293 cells. In A–E, data for the adjacent and diagonal channels are presented in the left and right panels, respectively. (A) K⁺ currents (I_K), recorded by conventional patch clamp, in response to depolarizing steps (gray traces), from −40 to 80 mV in 20-mV increments (see protocol below), fit with a power of an exponential function (black lines). (B) Inactivation of I_K (gray trace) during a pulse to 0 mV for 10 s, fitted with a double-exponential function (black line). (C) Deactivation of I_K (gray traces) at −60, −90, or −120 mV after a 50-ms depolarization at +60 mV, fitted with a mono-exponential function (black lines). (D) Time constants associated with activation (>−50 mV) or deactivation (<−50 mV); lines are fits of exponential functions. Error bars represent ± SEM; n = 3. (E) Conductance–voltage relationship of I_K currents after 100 ms at the indicated voltages from the forward adjacent (○; Kv1.1-1.1-1.2-1.2), reverse adjacent (•; Kv1.2-1.2-1.1-1.1), the forward diagonal (□; Kv1.1-1.2-1.1-1.2), and the reverse adjacent (▪; Kv1.2-1.1-1.2-1.1), calculated using −55 mV as reversal potential. Line is a Boltzmann fit, and parameters are shown in Table I. Error bars represent ± SD; some error bars fall within the data points; n ≥ 7.