title: Auxin efflux by PIN-FORMED proteins is activated by two different protein kinases, D6 PROTEIN KINASE and PINOID.
abstract: The development and morphology of vascular plants is critically determined by synthesis and proper distribution of the phytohormone auxin. The directed cell-to-cell distribution of auxin is achieved through a system of auxin influx and efflux transporters. PIN-FORMED (PIN) proteins are proposed auxin efflux transporters, and auxin fluxes can seemingly be predicted based on the--in many cells--asymmetric plasma membrane distribution of PINs. Here, we show in a heterologous Xenopus oocyte system as well as in Arabidopsis thaliana inflorescence stems that PIN-mediated auxin transport is directly activated by D6 PROTEIN KINASE (D6PK) and PINOID (PID)/WAG kinases of the Arabidopsis AGCVIII kinase family. At the same time, we reveal that D6PKs and PID have differential phosphosite preferences. Our study suggests that PIN activation by protein kinases is a crucial component of auxin transport control that must be taken into account to understand auxin distribution within the plant.
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Melina
authors.initials: M
authors.lastname: Zourelidou
authors.affiliation: Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Absmanner
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Weller
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Inês C R
authors.initials: IC
authors.lastname: Barbosa
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Björn C
authors.initials: BC
authors.lastname: Willige
authors.affiliation: Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany.
authors.forename: Astrid
authors.initials: A
authors.lastname: Fastner
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Verena
authors.initials: V
authors.lastname: Streit
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Port
authors.affiliation: Unité de Recherche en Génomique Végétale, Université Evry, Evry, France.
authors.forename: Jean
authors.initials: J
authors.lastname: Colcombet
authors.affiliation: Unité de Recherche en Génomique Végétale, Université Evry, Evry, France.
authors.forename: Sergio
authors.initials: S
authors.lastname: de la Fuente van Bentem
authors.affiliation: Unité de Recherche en Génomique Végétale, Université Evry, Evry, France.
authors.forename: Heribert
authors.initials: H
authors.lastname: Hirt
authors.affiliation: Proteomics and Bioanalytics, Technische Universität München, Freising, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Kuster
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, Potsdam, Germany.
authors.forename: Waltraud X
authors.initials: WX
authors.lastname: Schulze
authors.affiliation: Department of Cell Biology and Plant Biochemistry, Universität Regensburg, Regensburg, Germany.
authors.forename: Ulrich Z
authors.initials: UZ
authors.lastname: Hammes
authors.affiliation: Department of Plant Systems Biology, Technische Universität München, Freising, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Schwechheimer
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D007210:Indoleacetic Acids / Q000737:chemistry*; D018613:Microscopy, Confocal; D009154:Mutation; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014981:Xenopus
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; C030737:indoleacetic acid; C585918:D6PK protein, Arabidopsis; D011494:Protein Kinases; C405165:PINOID protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases
keywords: AGC kinases; arabidopsis; auxin; auxin transport; plant biology; protein kinase