title: Conversion of an instantaneous activating K+channel into a slow activating inward rectifier.
abstract: The miniature channel, Kcv, is a structural equivalent of the pore of all K+channels. Here, we follow up on a previous observation that a largely voltage-insensitive channel can be converted into a slow activating inward rectifier after extending the outer transmembrane domain by one Ala. This gain of rectification can be rationalized by dynamic salt bridges at the cytosolic entrance to the channel; opening is favored by voltage-sensitive formation of salt bridges and counteracted by their disruption. Such latent voltage sensitivity in the pore could be relevant for the understanding of voltage gating in complex Kv channels.
authors.affiliation: Plant Membrane Biophysics, Technical University Darmstadt, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Baumeister
authors.affiliation: Plant Membrane Biophysics, Technical University Darmstadt, Germany.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Hertel
authors.affiliation: Plant Membrane Biophysics, Technical University Darmstadt, Germany.
authors.forename: Indra
authors.initials: I
authors.lastname: Schroeder
authors.affiliation: Department of Biosciences and CNR IBF-Mi, Università degli Studi di Milano, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Gazzarrini
authors.affiliation: Physikalische Chemie III, Technische Universität Dortmund, Germany.
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Kast
authors.affiliation: Department of Plant Pathology, Nebraska Center for Virology, University of Nebraska Lincoln, NE, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Van Etten
authors.affiliation: Department of Biosciences and CNR IBF-Mi, Università degli Studi di Milano, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Moroni
authors.affiliation: Plant Membrane Biophysics, Technical University Darmstadt, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Thiel
mesh_terms: D049452:Green Fluorescent Proteins / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating; D007700:Kinetics; D008954:Models, Biological; D050505:Mutant Proteins / Q000378:metabolism; D015221:Potassium Channels / Q000378:metabolism*; D024661:Potassium Channels, Inwardly Rectifying / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013696:Temperature
chemical_list: D050505:Mutant Proteins; D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins
keywords: Kcv K+ channel; inward rectification; salt bridges; voltage-dependent gating