title: Antagonistic regulation of PIN phosphorylation by PP2A and PINOID directs auxin flux.
abstract: In plants, cell polarity and tissue patterning are connected by intercellular flow of the phytohormone auxin, whose directional signaling depends on polar subcellular localization of PIN auxin transport proteins. The mechanism of polar targeting of PINs or other cargos in plants is largely unidentified, with the PINOID kinase being the only known molecular component. Here, we identify PP2A phosphatase as an important regulator of PIN apical-basal targeting and auxin distribution. Genetic analysis, localization, and phosphorylation studies demonstrate that PP2A and PINOID both partially colocalize with PINs and act antagonistically on the phosphorylation state of their central hydrophilic loop, hence mediating PIN apical-basal polar targeting. Thus, in plants, polar sorting by the reversible phosphorylation of cargos allows for their conditional delivery to specific intracellular destinations. In the case of PIN proteins, this mechanism enables switches in the direction of intercellular auxin fluxes, which mediate differential growth, tissue patterning, and organogenesis.
authors: Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Tübingen, Germany.
authors: Marta
authors: M
authors: Michniewicz
authors: Marcelo K
authors: MK
authors: Zago
authors: Lindy
authors: L
authors: Abas
authors: Dolf
authors: D
authors: Weijers
authors: Alois
authors: A
authors: Schweighofer
authors: Irute
authors: I
authors: Meskiene
authors: Marcus G
authors: MG
authors: Heisler
authors: Carolyn
authors: C
authors: Ohno
authors: Jing
authors: J
authors: Zhang
authors: Fang
authors: F
authors: Huang
authors: Rebecca
authors: R
authors: Schwab
authors: Detlef
authors: D
authors: Weigel
authors: Elliot M
authors: EM
authors: Meyerowitz
authors: Christian
authors: C
authors: Luschnig
authors: Remko
authors: R
authors: Offringa
authors: Jirí
authors: J
authors: Friml
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D016764:Cell Polarity; D011992:Endosomes / Q000378:metabolism; D005838:Genotype; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D018519:Meristem / Q000201:enzymology / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D010749:Phosphoprotein Phosphatases / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D030821:Plants, Genetically Modified / Q000196:embryology / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D036226:Seedlings / Q000201:enzymology / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D010749:Phosphoprotein Phosphatases; D017346:Protein Serine-Threonine Kinases; D021122:Protein Subunits; D011993:Recombinant Fusion Proteins; C116363:PIN1 protein, Arabidopsis; C117013:AT5G57090 protein, Arabidopsis; C451260:PIN4 protein, Arabidopsis; C405165:PINOID protein, Arabidopsis