title: Alphavirus 6K proteins form ion channels.
abstract: Ross River virus and Barmah Forest virus are Australian arboviruses of the Alphavirus genus. Features of alphavirus infection include an increased permeability of cells to monovalent cations followed by virion budding. Virally encoded ion channels are thought to have a role in these processes. In this paper, the 6K proteins of Ross River virus and Barmah Forest virus are shown to form cation-selective ion channels in planar lipid bilayers. Using a novel purification method, bacterially expressed 6K proteins were inserted into bilayers with a defined orientation (i.e. N-terminal cis, C-terminal trans). Channel activity was reversibly inhibited by antibodies to the N and C termini of 6K protein added to the cis and trans baths, respectively. Channel conductances varied from 40-800 picosiemens, suggesting that the protein is able to form channels with a range of possible oligomerization states.
authors.affiliation: Division of Molecular Bioscience, John Curtin School of Medical Research, The Australian National University, GPO Box 334, Canberra ACT 2601, Australia.
authors.forename: Julian V
authors.initials: JV
authors.lastname: Melton
authors.forename: Gary D
authors.initials: GD
authors.lastname: Ewart
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Weir
authors.forename: Philip G
authors.initials: PG
authors.lastname: Board
authors.forename: Eva
authors.initials: E
authors.lastname: Lee
authors.forename: Peter W
authors.initials: PW
authors.lastname: Gage
mesh_terms: D000524:Alphavirus / Q000378:metabolism*; D000595:Amino Acid Sequence; D015153:Blotting, Western; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004594:Electrophysiology; D004926:Escherichia coli / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007473:Ion Channels / Q000737:chemistry*; D007477:Ions / Q000378:metabolism; D008051:Lipid Bilayers / Q000378:metabolism; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013997:Time Factors; D014764:Viral Proteins / Q000737:chemistry
chemical_list: D018076:DNA, Complementary; D007473:Ion Channels; D007477:Ions; D008051:Lipid Bilayers; D010455:Peptides; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D005982:Glutathione Transferase