title: ROOT ULTRAVIOLET B-SENSITIVE1/weak auxin response3 is essential for polar auxin transport in Arabidopsis.
abstract: The phytohormone auxin regulates virtually every aspect of plant development. To identify new genes involved in auxin activity, a genetic screen was performed for Arabidopsis (Arabidopsis thaliana) mutants with altered expression of the auxin-responsive reporter DR5rev:GFP. One of the mutants recovered in the screen, designated as weak auxin response3 (wxr3), exhibits much lower DR5rev:GFP expression when treated with the synthetic auxin 2,4-dichlorophenoxyacetic acid and displays severe defects in root development. The wxr3 mutant decreases polar auxin transport and results in a disruption of the asymmetric auxin distribution. The levels of the auxin transporters AUXIN1 and PIN-FORMED are dramatically reduced in the wxr3 root tip. Molecular analyses demonstrate that WXR3 is ROOT ULTRAVIOLET B-SENSITIVE1 (RUS1), a member of the conserved Domain of Unknown Function647 protein family found in diverse eukaryotic organisms. Our data suggest that RUS1/WXR3 plays an essential role in the regulation of polar auxin transport by maintaining the proper level of auxin transporters on the plasma membrane.
authors.affiliation: Howard Hughes Medical Institute and Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA.
authors.forename: Hong
authors.initials: H
authors.lastname: Yu
authors.forename: Michael
authors.initials: M
authors.lastname: Karampelias
authors.forename: Stephanie
authors.initials: S
authors.lastname: Robert
authors.forename: Wendy Ann
authors.initials: WA
authors.lastname: Peer
authors.forename: Ranjan
authors.initials: R
authors.lastname: Swarup
authors.forename: Songqing
authors.initials: S
authors.lastname: Ye
authors.forename: Lei
authors.initials: L
authors.lastname: Ge
authors.forename: Jerry
authors.initials: J
authors.lastname: Cohen
authors.forename: Angus
authors.initials: A
authors.lastname: Murphy
authors.forename: Jirí
authors.initials: J
authors.lastname: Friml
authors.forename: Mark
authors.initials: M
authors.lastname: Estelle
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D044783:F-Box Proteins / Q000235:genetics / Q000378:metabolism; D007210:Indoleacetic Acids / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D018519:Meristem / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development; D030821:Plants, Genetically Modified; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D015084:2,4-Dichlorophenoxyacetic Acid; D029681:Arabidopsis Proteins; D044783:F-Box Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; D011956:Receptors, Cell Surface; C116363:PIN1 protein, Arabidopsis; C117013:AT5G57090 protein, Arabidopsis; C543709:RUS1 protein, Arabidopsis; C501405:TIR1 protein, Arabidopsis