title: Post-translational regulation of nitrogen transporters in plants and microorganisms.
abstract: For microorganisms and plants, nitrate and ammonium are the main nitrogen sources and they are also important signaling molecules controlling several aspects of metabolism and development. Over the past decade, numerous studies revealed that nitrogen transporters are strongly regulated at the transcriptional level. However, more and more reports are now showing that nitrate and ammonium transporters are also subjected to post-translational regulations in response to nitrogen availability. Phosphorylation is so far the most well studied post-translational modification for these transporters and it affects both the regulation of nitrogen uptake and nitrogen sensing. For example, in Arabidopsis thaliana, phosphorylation was shown to activate the sensing function of the root nitrate transporter NRT1.1 and to switch the transport affinity. Also, for ammonium transporters, a phosphorylation-dependent activation/inactivation mechanism was elucidated in recent years in both plants and microorganisms. However, despite the fact that these regulatory mechanisms are starting to be thoroughly described, the signaling pathways involved and their action on nitrogen transporters remain largely unknown. In this review, we highlight the inorganic nitrogen transporters regulated at the post-translational level and we compare the known mechanisms in plants and microorganisms. We then discuss how these mechanisms could contribute to the regulation of nitrogen uptake and/or nitrogen sensing.
authors.affiliation: Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes 'Claude Grignon', UMR CNRS/INRA/SupAgro/UM2, Place Viala, 34060 Montpellier cedex, France.
authors.forename: Aurore
authors.initials: A
authors.lastname: Jacquot
authors.affiliation: Institute of Physiology and Biotechnology of plants, Plant Systems Biology, University of Hohenheim, Garbenstrasse 30, D-70593, Stuttgart, Germany.
authors.forename: Zhi
authors.initials: Z
authors.lastname: Li
authors.affiliation: Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes 'Claude Grignon', UMR CNRS/INRA/SupAgro/UM2, Place Viala, 34060 Montpellier cedex, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Gojon
authors.affiliation: Institute of Physiology and Biotechnology of plants, Plant Systems Biology, University of Hohenheim, Garbenstrasse 30, D-70593, Stuttgart, Germany.
authors.forename: Waltraud
authors.initials: W
authors.lastname: Schulze
authors.affiliation: Laboratoire de Biochimie et Physiologie Moléculaire des Plantes, Institut de Biologie Intégrative des Plantes 'Claude Grignon', UMR CNRS/INRA/SupAgro/UM2, Place Viala, 34060 Montpellier cedex, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Lejay
mesh_terms: D027321:Anion Transport Proteins / Q000235:genetics* / Q000378:metabolism; D001419:Bacteria / Q000235:genetics* / Q000378:metabolism; D005658:Fungi / Q000235:genetics* / Q000378:metabolism; D000091285:Nitrate Transporters; D009584:Nitrogen / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D010944:Plants / Q000235:genetics* / Q000378:metabolism; D011499:Protein Processing, Post-Translational
chemical_list: D027321:Anion Transport Proteins; D000091285:Nitrate Transporters; D010940:Plant Proteins; D009584:Nitrogen
keywords: Ammonium uptake; nitrate uptake; nitrogen transporter; phosphorylation; plants; post-translational regulation; yeast.