Progress in the Study of Potassium Channels in Cardiomyocytes
ZHOU Ying-Ying; LIU Tai-Feng(National Laboratory of Biomembrane and Membrane Engineering, College of Peking University,Beijing 100871)
The application of molecular biology and the development of patch clamp techniques led to a dramatic progress in the study of diversified and complicated K+ channels in the cardiomyocytes.Molecular studies suggested that all K+ channels are composed of four subunits units encoded by genes from a big K+ channel gene family. The mechanisms of K+ channel inactivation include N-, C- and p-types of inactivation. S5-S6 linker was postulated to form the pore of K+ channels by site- directed mutagenesis. Though the molecular structures among K+ channels are very close, a wide range of their functional properties has been observed.The channel conductances, the characterizations of activation, inactivation, rectification and external K+ sensitivity.the agonists,antagonists and modulators of eight K+ channels found in cardiomyocytes up to now are different with each other.