title: Transport Function of Rice Amino Acid Permeases (AAPs).
abstract: The transport function of four rice (Oryza sativa) amino acid permeases (AAPs), OsAAP1 (Os07g04180), OsAAP3 (Os06g36180), OsAAP7 (Os05g34980) and OsAAP16 (Os12g08090), was analyzed by expression in Xenopus laevis oocytes and electrophysiology. OsAAP1, OsAAP7 and OsAAP16 functioned, similarly to Arabidopsis AAPs, as general amino acid permeases. OsAAP3 had a distinct substrate specificity compared with other rice or Arabidopsis AAPs. OsAAP3 transported the basic amino acids lysine and arginine well but selected against aromatic amino acids. The transport of basic amino acids was further analyzed for OsAAP1 and OsAAP3, and the results support the transport of both neutral and positively charged forms of basic amino acids by the rice AAPs. Cellular localization using the tandem enhanced green fluorescent protein (EGFP)-red fluorescent protein (RFP) reporter pHusion showed that OsAAP1 and OsAAP3 localized to the plasma membrane after transient expression in onion epidermal cells or stable expression in Arabidopsis.
authors.affiliation: Department of Plant Biology, University of Minnesota, St. Paul, MN 55108, USA.
authors.forename: Margaret R
authors.initials: MR
authors.lastname: Taylor
authors.affiliation: Department of Plant Biology, University of Minnesota, St. Paul, MN 55108, USA.
authors.forename: Anke
authors.initials: A
authors.lastname: Reinders
authors.affiliation: Department of Plant Biology, University of Minnesota, St. Paul, MN 55108, USA jward@umn.edu.
authors.forename: John M
authors.initials: JM
authors.lastname: Ward
mesh_terms: D026905:Amino Acid Transport Systems / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001692:Biological Transport; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008564:Membrane Potentials; D018613:Microscopy, Confocal; D019697:Onions / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism / Q000502:physiology; D012275:Oryza / Q000201:enzymology / Q000235:genetics*; D010802:Phylogeny; D019441:Plant Epidermis / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013379:Substrate Specificity; D014982:Xenopus laevis
chemical_list: D026905:Amino Acid Transport Systems; D000596:Amino Acids; D007527:Isoenzymes; D010940:Plant Proteins; D049452:Green Fluorescent Proteins
keywords: Xenopus oocytes; amino acid transporters; electrophysiology; rice AAPs