Fig. 3: hGIRK2G154S compared to hGIRK2wt.
From: A selectivity filter mutation provides insights into gating regulation of a K+ channel
a Representative of whole cell current records from hGIRK2wt with Gβγ. Sequential changes of solutions and subsequent Ba2+ block are shown. The holding potential was −80 mV, and the recording always started in low-K+ (2 mM) solution. b Representative recordings of whole-cell currents from hGIRK2wt with Gβγ. 2 s voltage ramps from −120 to +50 mV are performed in each solution. Record from each solution is shown in a different color. Voltage protocol is shown in the lower panel. c I–V curves in a representative oocyte expressing hGIRK2wt with Gβγ tested in four solutions. Ba2+ sensitive currents are shown. d Representative recordings of whole-cell currents from hGIRK2G154S with Gβγ. 2 s voltage ramps from −120 mV to +50 mV are performed in each solution. e I-V curves in a representative oocyte expressing hGIRK2G154S with Gβγ in the 2 mM K+ solution (black) along with QX block (red), QX sensitive currents (green) and the net QX currents obtained from subtracting average native currents from QX sensitive currents (cyan) are shown. f hGIRK2wt and hGIRK2G154S currents with and without Gβγ, before and after QX314 (1 mM) application, in 4–7 oocytes from one frog, are shown. Paired t-test followed by Wilcoxon test was performed. **p = 0.0078 and *p = 0.0156; n.s. is not significant (p > 0.05).
