Figure 1.
Characterization of calmodulin-dependent Kv7.2 potentiation. (A) Effect of CaM on Kv7.2 current density as a function of the amount of channel cDNA transfected. Mean current density (pA/pF) in cells transfected with channels only (black symbols) or together with 3 μg CaM cDNA per 35 mm dish (red symbols). (B) Effect of increasing CaM on Kv7.2 density. Half maximal CaM effect was obtained approximately when transfecting cells at a 1:2 (w/w) Kv7.2/CaM cDNA ratio. Inset: Representative current traces recorded from HEK293T cells transfected with 0.15 μg Kv7.2 cDNA and, where indicated, with 3 μg CaM cDNA, to illustrate current density quantification. Maximum current was measured at −30 mV as the difference in the amplitude after a pre-pulse to −110 mV to close all channels and after a prepulse to +30 mV to reach maximum Popen (arrow).