Fig. 7. Electrophysiological properties of 2xL-A-KCNQ1 and Y51A-KCNQ1. (A) Representative traces from MDCK cells expressing wt-KCNQ1, Y51A-KCNQ1, and 2xL-A-KCNQ1 channels. The traces were obtained after stepping from –80 mV to +60 mV for 2 seconds followed by 0.5 seconds at – 30 mV. (B) Mean current values of MDCK cells expressing wt-KCNQ1 or mutated KCNQ1. Peak current values, measured at +60 mV, were as follows: 296±52 (n=5) for wt-KCNQ1, 114±35 pA (n=8) for 2xL-A-KCNQ1, 265±70 pA (n=8) for Y51A-KCNQ1, 27±6 pA (n=5) for Y111A-KCNQ1, and 24±10 pA (n=4) for Y111C-KCNQ1.