Functional heterogeneity of arrhythmogenic KCNQ1 S1 mutants reveals dependence on the number of KCNE1 subunits in the IKs channel complex.
BACKGROUND A cluster of closely spaced residues located at the extracellular end of the S1 transmembrane domain in KCNQ1 (Q1, residues 140-147) harbors six mutations associated with both gain- and loss-of-function (GoF and LoF) arrhythmic diseases. Whether severity of the mutation phenotype is affected by the stoichiom...