Coexpression of Slc7a5 accelerates Kvβ-mediated inactivation kinetics in WT Kv1.2 channels. (A) LM cells were transfected with WT Kv1.2 + Kvβ or WT Kv1.2 + Kvβ + Slc7a5 with transfection ratios as previously mentioned. Cells were hyperpolarized to −120 mV for 30 s before recording, to disinhibit Kv1.2 currents. Time constants of inactivation (τ inact) were calculated from a single exponential fit of the inactivating current at depolarizing sweeps from 50 to 110 mV in 10-mV increments for 100 ms from a −100-mV holding potential (n = 19–23 individual cells recorded for each group). (B) τ Inactivation of individual cells from each group in A were obtained from the inactivating currents at +100 mV from a −100-mV holding voltage (n = 19–23 individual cells recorded for each group; Student’s t test was used to compare the Slc7a5 treatment group versus the respective control; P values are denoted above the box plots). (C) Representative traces of LM cells were depolarized to +100 mV for 40 ms from a −100-mV holding potential. Box plots depict the median, 25th, and 75th percentiles (box) and the 10th and 90th percentiles (whiskers).