title: Auxin-mediated ribosomal biogenesis regulates vacuolar trafficking in Arabidopsis.
abstract: In plants, the mechanisms that regulate the transit of vacuolar soluble proteins containing C-terminal and N-terminal vacuolar sorting determinants (VSDs) to the vacuole are largely unknown. In a screen for Arabidopsis thaliana mutants affected in the trafficking of C-terminal VSD containing proteins, we isolated the ribosomal biogenesis mutant rpl4a characterized by its partial secretion of vacuolar targeted proteins and a plethora of developmental phenotypes derived from its aberrant auxin responses. In this study, we show that ribosomal biogenesis can be directly regulated by auxins and that the exogenous application of auxins to wild-type plants results in vacuolar trafficking defects similar to those observed in rpl4a mutants. We propose that the influence of auxin on ribosomal biogenesis acts as a regulatory mechanism for auxin-mediated developmental processes, and we demonstrate the involvement of this regulatory mechanism in the sorting of vacuolar targeted proteins in Arabidopsis.
authors.affiliation: Department of Botany and Plant Sciences and Center for Plant Cell Biology, University of California, Riverside, California 92521, USA.
authors.forename: Abel
authors.initials: A
authors.lastname: Rosado
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Sohn
authors.forename: Georgia
authors.initials: G
authors.lastname: Drakakaki
authors.forename: Songqin
authors.initials: S
authors.lastname: Pan
authors.forename: Alexandra
authors.initials: A
authors.lastname: Swidergal
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Xiong
authors.forename: Byung-Ho
authors.initials: BH
authors.lastname: Kang
authors.forename: Ray A
authors.initials: RA
authors.lastname: Bressan
authors.forename: Natasha V
authors.initials: NV
authors.lastname: Raikhel
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000096:biosynthesis* / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D007210:Indoleacetic Acids / Q000378:metabolism*; D016254:Mutagenesis, Insertional; D009154:Mutation; D021381:Protein Transport; D020543:Proteome / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics; D012269:Ribosomal Proteins / Q000096:biosynthesis* / Q000235:genetics; D014617:Vacuoles / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D007210:Indoleacetic Acids; D020543:Proteome; D018749:RNA, Plant; D012269:Ribosomal Proteins; C036483:T-DNA; C056368:ribosomal protein L4