Figure 6.

Slc7a5 accelerates Kvβ-mediated N-type inactivation of Kv1.2 channels. LM cells were transfected with Kv1.2[T252R] + Kvβ or Kv1.2[T252R] + Kvβ + Slc7a5 with transfection ratios as previously mentioned. Cells were hyperpolarized to −120 mV for 30 s before recording, to disinhibit Kv1.2 currents. (A) 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 (mean ± SEM) at each voltage (n = 19–20 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. τ inact (ms) at +100 mV ± SD; Kv1.2[T252R] + Kvβ = 7.2 ± 2.5; Kv1.2[T252R] + Kvβ + Slc7a5 = 5.3 ± 1.1; n = 19–20 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).