title: MODULATOR OF PIN genes control steady-state levels of Arabidopsis PIN proteins.
abstract: Polar transport of the phytohormone auxin controls numerous growth responses in plants. Molecular characterization of auxin transport in Arabidopsis thaliana has provided important insights into the mechanisms underlying the regulation of auxin distribution. In particular, the control of subcellular localization and expression of PIN-type auxin efflux components appears to be fundamental for orchestrated distribution of the growth regulator throughout the entire plant body. Here we describe the identification of two Arabidopsis loci, MOP2 and MOP3 (for MODULATOR OF PIN), that are involved in control of the steady-state levels of PIN protein. Mutations in both loci result in defects in auxin distribution and polar auxin transport, and cause phenotypes consistent with a reduction of PIN protein levels. Genetic interaction between PIN2 and both MOP loci is suggestive of functional cross-talk, which is further substantiated by findings demonstrating that ectopic PIN up-regulation is compensated in the mop background. Thus, in addition to pathways that control PIN localization and transcription, MOP2 and MOP3 appear to be involved in fine-tuning of auxin distribution via post-transcriptional regulation of PIN expression.
authors.affiliation: Institute for Applied Genetics and Cell Biology, University of Applied Life Sciences and Natural Resources (BOKU), Muthgasse 18, A-1190 Vienna, Austria.
authors.forename: Nenad
authors.initials: N
authors.lastname: Malenica
authors.forename: Lindy
authors.initials: L
authors.lastname: Abas
authors.forename: René
authors.initials: R
authors.lastname: Benjamins
authors.forename: Saeko
authors.initials: S
authors.lastname: Kitakura
authors.forename: Harald F
authors.initials: HF
authors.lastname: Sigmund
authors.forename: Kim S
authors.initials: KS
authors.lastname: Jun
authors.forename: Marie-Theres
authors.initials: MT
authors.lastname: Hauser
authors.forename: Jirí
authors.initials: J
authors.lastname: Friml
authors.forename: Christian
authors.initials: C
authors.lastname: Luschnig
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D015152:Blotting, Northern; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant / Q000235:genetics*; D007150:Immunohistochemistry; D007210:Indoleacetic Acids / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D018517:Plant Roots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D018520:Plant Shoots / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D026901:Membrane Transport Proteins; C116363:PIN1 protein, Arabidopsis; D011993:Recombinant Fusion Proteins