title: Nitrate transport capacity of the Arabidopsis thaliana NRT2 family members and their interactions with AtNAR2.1.
abstract: • Interactions between the Arabidopsis NitRate Transporter (AtNRT2.1) and Nitrate Assimilation Related protein (AtNAR2.1, also known as AtNRT3.1) have been well documented, and confirmed by the demonstration that AtNRT2.1 and AtNAR2.1 form a 150-kDa plasma membrane complex, thought to constitute the high-affinity nitrate transporter of Arabidopsis thaliana roots. Here, we have investigated interactions between the remaining AtNRT2 family members (AtNRT2.2 to AtNRT2.7) and AtNAR2.1, and their capacity for nitrate transport. • Three different systems were used to examine possible interactions with AtNAR2.1: membrane yeast split-ubiquitin, bimolecular fluorescence complementation in A. thaliana protoplasts and nitrate uptake in Xenopus oocytes. • All NRT2s, except for AtNRT2.7, restored growth and β-galactosidase activity in the yeast split-ubiquitin system, and split-YFP fluorescence in A. thaliana protoplasts only when co-expressed with AtNAR2.1. Thus, except for AtNRT2.7, all other NRT2 transporters interact strongly with AtNAR2.1. • Co-injection into Xenopus oocytes of cRNA of all NRT2 genes together with cRNA of AtNAR2.1 resulted in statistically significant increases of uptake over and above that resulting from single cRNA injections.
authors.affiliation: University of British Columbia, 6270 University Blvd, Vancouver, BC V6T1Z4, Canada.
authors.forename: Zorica
authors.initials: Z
authors.lastname: Kotur
authors.affiliation: University of Adelaide, PRC, 2B Hartley Grove, Urrbrae, SA 5064, Australia.
authors.forename: Nenah
authors.initials: N
authors.lastname: Mackenzie
authors.affiliation: University of Adelaide, PRC, 2B Hartley Grove, Urrbrae, SA 5064, Australia.
authors.forename: Sunita
authors.initials: S
authors.lastname: Ramesh
authors.affiliation: University of Adelaide, PRC, 2B Hartley Grove, Urrbrae, SA 5064, Australia.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Tyerman
authors.affiliation: University of Adelaide, PRC, 2B Hartley Grove, Urrbrae, SA 5064, Australia.
authors.forename: Brent N
authors.initials: BN
authors.lastname: Kaiser
authors.affiliation: University of British Columbia, 6270 University Blvd, Vancouver, BC V6T1Z4, Canada.
authors.forename: Anthony D M
authors.initials: ADM
authors.lastname: Glass
mesh_terms: D000818:Animals; D027321:Anion Transport Proteins / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D009154:Mutation; D009566:Nitrates / Q000378:metabolism*; D009587:Nitrogen Isotopes / Q000032:analysis; D009865:Oocytes; D018515:Plant Leaves; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D025941:Protein Interaction Mapping; D011523:Protoplasts; D018075:RNA, Complementary / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D011993:Recombinant Fusion Proteins; D020798:Two-Hybrid System Techniques; D014981:Xenopus / Q000235:genetics / Q000378:metabolism
chemical_list: D027321:Anion Transport Proteins; D029681:Arabidopsis Proteins; D009566:Nitrates; D009587:Nitrogen Isotopes; D018075:RNA, Complementary; D018749:RNA, Plant; D011993:Recombinant Fusion Proteins; C516470:NAR2.1 protein, Arabidopsis; C510574:NRT3.1 protein, Arabidopsis; C477335:NRT2.1 protein, Arabidopsis