(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.


Figure 7


Fig. 7. Inactivation properties of CionaKv4 and an N-terminal deletion mutant of CionaKv4 (ntCionaKv4) in the presence/absence of CionaKChIP. (A) Comparison of the time constant of macroscopic inactivation ({tau} inactivation)-voltage relationships for (Ai) CionaKv4 alone (wt) or in the presence of CionaKChIP (wt+), (Aii) CionaKv4 (wt) and ntCionaKv4 (nt), and (Aiii) ntCionaKv4 alone (nt) or with CionaKChIP (nt+). {tau}1 (circles) and {tau}2 (squares) are the time constants of the fast and slow components of inactivation, respectively, of CionaKv4 (solid symbols) or ntCionaKv4 (open symbols) currents. {tau} (diamonds) is the time constant of the single component of inactivation of CionaKv4/KChIP (solid diamonds) or ntCionaKv4/KChIP (open diamonds). All inactivation kinetics appear to be insensitive to voltage. N=15. (B) Comparison of the time constant of deactivation ({tau} deactivation)-voltage relationships for (Bi) CionaKv4 alone or in the presence of CionaKChIP, (Bii) CionaKv4 and ntCionaKv4, and (Biii) ntCionaKv4 alone or with CionaKChIP. N=16. (C) Comparison of the steady-state inactivation curves for (Ci) CionaKv4 alone or with CionaKChIP, (Cii) CionaKv4 and ntCionaKv4, and (Ciii) ntCionaKv4 alone or with CionaKChIP. Solid curves represent first order Boltzmann fits of the averaged data. Steady-state inactivation was determined by measuring the peak current evoked with a depolarizing pulse to +50 mV as a function of the voltage of a preceding 10 s prepulse test (between -130 and -30 mV). N=8. (D) Comparison of the rates of recovery from inactivation for (Di) CionaKv4 alone or in the presence of CionaKChIP, (Dii) CionaKv4 and ntCionaKv4, and (Diii) ntCionaKv4 alone or in the presence of CionaKChIP. N=8. A double-pulse protocol was used with a test pulse to +50 mV lasting 1 s separated by a recovery period (at -100 mV) of increasing duration (50-2000 ms) from a second test pulse to +50 mV. The currents evoked by the second pulse (I0) were normalized to the currents produced by the first pulse (I) and plotted against the duration of the interpulse interval. Solid curves represent single exponential fits to the data. Values are means ± s.e.m.