Stoichiometry of the Slow Iks Potassium Channel in Human Embryonic Stem Cell-Derived Myocytes

摘要

The delayed rectifier Iks potassium channel is composed of α-(KCNQ1) and β-(KCNE1) subunits. The stoichiometry of Iks channels is a matter of some debate. Recently some investigators proposed that the number of KCNE1 subunits per KCNQ1 tetramer could be vary from one to four depending on the relative expression of these two genes. Here we review our previous study of biophysical properties of Iks in human embryonic stem cell–derived cardiomyocytes (hESC-CMs) showed that Iks in hESC-CMs is a coassembly channel with a stoichiometry other than 1:1, which could be further modulated by additional KCNE1.