Fig. 1. Biophysical properties of KCNQ1 channels and KCNQ1/KCNE1 channel complexes expressed in  Xenopus laevis oocytes. (  A and  B ) Representative currents evoked by the activation protocol through KCNQ1^wt(  A ) and KCNQ1^A344V(  B ) channels expressed without (  upper panel ) and with the subunit KCNE1 (  lower panel ). (  C ) Conductance–voltage relation of KCNQ1 wild-type (wt) and mutant (A344V) channels expressed with (+ E1) and without KCNE1 (− E1). Curves were fitted with Boltzmann functions (  table 1 ).