Fig. 5

Slc7a5 influences inactivation of Kv1.2. a Kv1.2[V381T] channels were expressed alone or with Slc7a5 (1:1 transfection ratio). Conductance-voltage relationships were generated with the same protocol as Fig. 4, after disinhibition by a 30 s hyperpolarization to −120 mV (Kv1.2[V381T] V_1/2= −16 ± 4 mV, k = 8.5 ± 0.7 mV, n = 6; + Slc7a5 V_1/2 = −55 ± 11 mV, k = 13.1 ± 3.2 mV, n = 8). b Current density at +60 mV was measured at the beginning and of a pulse train with −120 mV holding potential (identical to Fig. 3; Kv1.2[V381T] n = 8; +Slc7a5 n = 16). c Exemplar traces of Kv1.2[V381T] ± Slc7a5 (green) currents elicited by a 1 s depolarization to +60 mV (after current disinhibition by holding at −120 mV). d Steady-state inactivation was measured by pulsing to test voltages for 6 s and allowing channels to recover for 7 s at −100 mV. Curves were fit with a Boltzmann function (Kv1.2[V381T] V_1/2 = −31 ± 3 mV, k = 11.1 ± 2.1 mV, n = 5; Kv1.2[V381T] + Slc7a5 V_1/2= −69 ± 6 mV, k = 6.7 ± 1.8 mV, n = 5). e, f Identical experiments as in a, b were performed with Kv1.2[LT] channels (Kv1.2[LT] V_1/2 = +80 ± 10 mV, k = 18 ± 2 mV, n = 7; +Slc7a5 V_1/2 = +40 ± 11 mV, k = 17 ± 2 mV, n = 7). g Current disinhibition (fold change in current after a −120 mV pulse train) for Kv1.2[V381T] (n = 8, 16) or Kv1.2[LT] (n = 7, 7). Bars represent mean ± s.d., Student’s t-test was used to compare Slc7a5-mediated disinhibition vs. control with each channel type