title: Comparison of protein behavior between wild-type and G601S hERG in living cells by fluorescence correlation spectroscopy.
abstract: The human ether-a-go-go-related gene (hERG) protein is a cardiac potassium channel. Mutations in hERG can result in reductions in membrane channel current, cardiac repolarization, prolongation of QT intervals, and lethal arrhythmia. In the last decade, it has been found that some mutants of hERG involved in long QT syndrome exhibit intracellular protein trafficking defects, while other mutants sort to the membrane but cannot form functional channels. Due to the close relationship between intracellular trafficking and functional protein expression, we aimed to measure differences in protein behavior/motion between wild-type and mutant hERG by directly analyzing the fluorescence fluctuations of green fluorescent protein-labeled proteins using fluorescence correlation spectroscopy (FCS). Our data imply that FCS can be applied as a new diagnostic tool to assess whether the defect in a particular mutant channel protein involves aberrant intracellular trafficking.
authors.affiliation: International Research and Educational Institute for Integrated Medical Sciences (IREIIMS), Tokyo Women's Medical University, Kawata-cho, Shinjuku-ku, Tokyo, Japan. erihayakawa@jichi.ac.jp
authors.forename: Eri H
authors.initials: EH
authors.lastname: Hayakawa
authors.forename: Michiko
authors.initials: M
authors.lastname: Furutani
authors.forename: Rumiko
authors.initials: R
authors.lastname: Matsuoka
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Takakuwa
mesh_terms: D019943:Amino Acid Substitution / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004058:Diffusion; D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels / Q000235:genetics / Q000378:metabolism*; D006031:Glycosylation; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D021381:Protein Transport / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014162:Transfection
chemical_list: D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C000606913:KCNH2 protein, human; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins