Figure 8. The deletion form of OsKAT3 can recover the inward rectifying K⁺ channel activity in yeast and CHO cell.

A, CY162 yeast with the empty vector (EV, pYES-DEST52), or expression constructs for rice OsKAT2, OsKAT3 or deletion form of OsKAT3 (OsΔKAT3) was serially diluted (no dilution (1: 0), diluted 1:10 or 1:100 with sterile distilled water) and plated on solid SDGU medium containing 0, 2, 7, or 100mM KCl. B, representative whole cell currents recorded in CHO cells expressing C-terminal deleted OsKAT3. Currents were obtained by changing the membrane voltage from a holding potential of -20 mV followed by test pulses from -140 mV to +60 mV in 20 mV increments in the presence of various concentrations of external potassium, as indicated. C, steady-state current-voltage curves of whole cell recordings in the presence of 5 mM (■) (n=13), 50 mM (●) (n=13), and 170 mM (▲) (n=13) external potassium, respectively. Ba²⁺ inhibition of OsKAT3-mediated K⁺ _in currents (▽) (n=12). D, Current densities of OsKAT3, OsKAT3 and OsKAT2 at -140 mV in 170 mM [K⁺]_o. The numbers of samples used in the analysis are shown in parentheses.