--- res: bibo_abstract: - The shaping of organs in plants depends on the intercellular flow of the phytohormone auxin, of which the directional signaling is determined by the polar subcellular localization of PIN-FORMED (PIN) auxin transport proteins. Phosphorylation dynamics of PIN proteins are affected by the protein phosphatase 2A (PP2A) and the PINOID kinase, which act antagonistically to mediate their apical-basal polar delivery. Here, we identified the ROTUNDA3 (RON3) protein as a regulator of the PP2A phosphatase activity in Arabidopsis thaliana. The RON3 gene was map-based cloned starting from the ron3-1 leaf mutant and found to be a unique, plant-specific gene coding for a protein with high and dispersed proline content. The ron3-1 and ron3-2 mutant phenotypes [i.e., reduced apical dominance, primary root length, lateral root emergence, and growth; increased ectopic stages II, IV, and V lateral root primordia; decreased auxin maxima in indole-3-acetic acid (IAA)-treated root apical meristems; hypergravitropic root growth and response; increased IAA levels in shoot apices; and reduced auxin accumulation in root meristems] support a role for RON3 in auxin biology. The affinity-purified PP2A complex with RON3 as bait suggested that RON3 might act in PIN transporter trafficking. Indeed, pharmacological interference with vesicle trafficking processes revealed that single ron3-2 and double ron3-2 rcn1 mutants have altered PIN polarity and endocytosis in specific cells. Our data indicate that RON3 contributes to auxin-mediated development by playing a role in PIN recycling and polarity establishment through regulation of the PP2A complex activity.@eng bibo_authorlist: - foaf_Person: foaf_givenName: Michael foaf_name: Karampelias, Michael foaf_surname: Karampelias - foaf_Person: foaf_givenName: Pia foaf_name: Neyt, Pia foaf_surname: Neyt - foaf_Person: foaf_givenName: Steven foaf_name: De Groeve, Steven foaf_surname: De Groeve - foaf_Person: foaf_givenName: Stijn foaf_name: Aesaert, Stijn foaf_surname: Aesaert - foaf_Person: foaf_givenName: Griet foaf_name: Coussens, Griet foaf_surname: Coussens - foaf_Person: foaf_givenName: Jakub foaf_name: Rolčík, Jakub foaf_surname: Rolčík - foaf_Person: foaf_givenName: Leonardo foaf_name: Bruno, Leonardo foaf_surname: Bruno - foaf_Person: foaf_givenName: Nancy foaf_name: De Winne, Nancy foaf_surname: De Winne - foaf_Person: foaf_givenName: Annemie foaf_name: Van Minnebruggen, Annemie foaf_surname: Van Minnebruggen - foaf_Person: foaf_givenName: Marc foaf_name: Van Montagu, Marc foaf_surname: Van Montagu - foaf_Person: foaf_givenName: Maria foaf_name: Ponce, Maria foaf_surname: Ponce - foaf_Person: foaf_givenName: José foaf_name: Micol, José foaf_surname: Micol - foaf_Person: foaf_givenName: Jirí foaf_name: Friml, Jirí foaf_surname: Friml foaf_workInfoHomepage: http://www.librecat.org/personId=4159519E-F248-11E8-B48F-1D18A9856A87 orcid: 0000-0002-8302-7596 - foaf_Person: foaf_givenName: Geert foaf_name: De Jaeger, Geert foaf_surname: De Jaeger - foaf_Person: foaf_givenName: Mieke foaf_name: Van Lijsebettens, Mieke foaf_surname: Van Lijsebettens bibo_doi: 10.1073/pnas.1501343112 bibo_issue: '10' bibo_volume: 113 dct_date: 2016^xs_gYear dct_language: eng dct_publisher: National Academy of Sciences@ dct_title: ROTUNDA3 function in plant development by phosphatase 2A-mediated regulation of auxin transporter recycling@ ...