The 4:4 (Kv4.2/KChIP4) channel shows faster recovery than the 4:2 channel.
A, representative current traces showing the recovery from inactivation of the 4:2 channel (top) and the 4:4 channel (bottom). The currents were evoked by a two-pulse protocol, as shown in Fig. 3A (inset). B, comparison of the recovery kinetics of the tandem constructs with those of Kv4.2/KChIP4 co-expression. The 4:2 channel shows kinetics similar to that of Kv4.2 (5 ng) with KChIP4 (0.5 ng). The 4:4 channel shows kinetics similar to that of Kv4.2 (5 ng) with KChIP4 (5 ng). The recovery kinetics of the 4:2 channel with additional KChIP4 was comparable with that of the 4:4 channel (n = 4). C, the time constants of single exponential fits of the recovery taken from B. ***, statistically significant difference (p < 0.001 by Dunnett's test). Error bars, S.E.