title: Isolation and characterization of membrane vesicles of Saccharomyces cerevisiae harboring the high-affinity phosphate transporter.
abstract: Membrane vesicles with an inside-out orientation were isolated from the plasma membrane of Saccharomyces cerevisiae by an improved aqueous two-phase partitioning technique. The activity of the orthovanadate-sensitive H+-pumping ATPase, the plasma membrane marker, was highly enriched by the partitioning technique. The obtained results suggest that the membrane vesicles produced were predominantly oriented inside-out. The isolated plasma membrane vesicles displayed cross-reactions with antibodies raised against synthetic peptide corresponding to the N-terminal (residues 1-10) and the C-terminal (residues 578-597) regions of the plasma membrane phosphate transporter encoded by the PHO84 gene and the H+-pumping ATPase of S. cerevisiae. The purified membrane vesicles catalyzed a derepressible inhibitor-sensitive phosphate uptake at levels comparable with the situation in intact cells of S. cerevisiae indicating that transport of phosphate across the membrane is both functional and bidirectional. The PHO84 transporter harbored in isolated plasma membranes could moreover be enriched in a high state of purity by immunoaffinity chromatography using immobilized anti-PHO84 antibodies.
authors.affiliation: Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, University of Stockholm, Sweden.
authors.forename: U
authors.initials: U
authors.lastname: Fristedt
authors.forename: A
authors.initials: A
authors.lastname: Berhe
authors.forename: K
authors.initials: K
authors.lastname: Ensler
authors.lastname: Norling
authors.forename: B L
authors.initials: BL
authors.lastname: Persson
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000595:Amino Acid Sequence; D000906:Antibodies; D001692:Biological Transport; D015153:Blotting, Western; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism / Q000648:ultrastructure; D003576:Electron Transport Complex IV / Q000378:metabolism; D007700:Kinetics; D008969:Molecular Sequence Data; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D015388:Organelles / Q000378:metabolism / Q000648:ultrastructure; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology; D028044:Phosphate-Binding Proteins; D010710:Phosphates / Q000378:metabolism; D006180:Proton-Translocating ATPases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000648:ultrastructure; D014638:Vanadates / Q000494:pharmacology
chemical_list: D000906:Antibodies; D002352:Carrier Proteins; D010446:Peptide Fragments; D028044:Phosphate-Binding Proteins; D010710:Phosphates; D014638:Vanadates; D009251:NADPH-Ferrihemoprotein Reductase; D003576:Electron Transport Complex IV; D000251:Adenosine Triphosphatases; D006180:Proton-Translocating ATPases