title: Functional identification of AtAVT3, a family of vacuolar amino acid transporters, in Arabidopsis.
abstract: Amino acids stored in the vacuoles are exported to the cytosol mainly for protein synthesis; however, the molecular identity of vacuolar amino acid exporters remains obscure in plants. Here, we demonstrate that the heterologous expression of AtAVT3 genes, Arabidopsis homologs of AVT3 and AVT4 encoding vacuolar amino acid exporters in yeast, reduces vacuolar amino acid levels in the avt3∆avt4∆ yeast cells. In vitro experiments revealed that14C-labeled Ala and Pro are exported from vacuolar membrane vesicles by AtAvt3A in an ATP-dependent manner. In Arabidopsis, AtAvt3A fused with green fluorescent protein localizes to the vacuolar membrane. We propose that AtAVT3 family represents the long sought-for vacuolar amino acid exporters in plants.
authors.affiliation: Division of Life Science, Graduate School of Science and Engineering, Saitama University, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Fujiki
authors.affiliation: Department of Applied Bioscience, Faculty of Agriculture, Ehime University, Japan.
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Teshima
authors.affiliation: Department of Applied Bioscience, Faculty of Agriculture, Ehime University, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Kashiwao
authors.affiliation: Department of Applied Bioscience, Faculty of Agriculture, Ehime University, Japan.|Advanced Research Support Center (ADRES), Ehime University, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Kawano-Kawada
authors.affiliation: Frontier Research Center, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ohsumi
authors.affiliation: Department of Applied Bioscience, Faculty of Agriculture, Ehime University, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kakinuma
authors.affiliation: Department of Applied Bioscience, Faculty of Agriculture, Ehime University, Japan.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Sekito
mesh_terms: D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D018506:Gene Expression Regulation, Plant; D007425:Intracellular Membranes / Q000378:metabolism; D010802:Phylogeny; D059828:Plant Cells / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D026905:Amino Acid Transport Systems; D000596:Amino Acids; D029681:Arabidopsis Proteins
keywords: 
  Arabidopsis
  ; amino acid transporter; export; vacuole; yeast