Functional interactions of Slc7a5 and Kvβ influence the deactivation kinetics of Kv1.2. LM cells were transfected with combinations of WT Kv1.2, Kvβ, and Slc7a5 as previously mentioned. Cells were depolarized to +20 mV for 200 ms followed by repolarizing steps from −60 to −150 mV in 10-mV increments for 600 ms before returning to a −100-mV holding potential. Time constants of deactivation (mean ± SD) were calculated from single (WT Kv1.2; Kv1.2 + Kvβ; Kv1.2 + Slc7a5) or double (Kv1.2 + Kvβ + Slc7a5) exponential functions of the deactivation tail currents obtained from repolarizing voltage sweeps of −60 to −150 mV from a +20-mV depolarizing step (n = 11–18 individual cells recorded for each group).