Effect of the stoichiometry of ILT subunits on Shaker activation and deactivation kinetics. (A) Activation time constants (τact) and (B) deactivation time constants (τdeact) of the heterotetramers compared with that of 4ILT. The weighted τact as a function of the activating membrane potential is shown. The inset illustrates a current trace (black) at +160 mV from an oocyte expressing 4ILT, a fit with a single (red) and double (blue) exponential function. The vertical dotted line indicates the time position for the beginning of the fit. The internal and external solutions contained 120 and 12 mM K+, respectively. The weighted τdeact from an activating pulse at +160 mV plotted against the returning membrane potential. The internal and external solutions contained 120 and 50 mM K+, respectively. 4wt (black squares, n = 5), 1ILT/3wt (red circles, n = 3), 2ILT/2wt (blue up triangles, n = 3), 3ILT/1wt (green down triangles, n = 3), 4ILT (yellow diamonds, n = 4). Data from 4wt was taken from Fig. 4 of Gagnon and Bezanilla (2009).
