title: Mutual control of intracellular localisation of the patterning proteins AtMYC1, GL1 and TRY/CPC in Arabidopsis.
abstract: Trichome and root hair patterning is governed by a gene regulatory network involving TTG1 and several homologous MYB and bHLH proteins. The bHLH proteins GL3 and EGL3 are core components that serve as a regulatory platform for the activation of downstream genes. In this study we show that a homologue of GL3 and EGL3, AtMYC1, can regulate the intracellular localisation of GL1 and TRY. AtMYC1 protein is predominantly localised in the cytoplasm and can relocate GL1 from the nucleus into the cytoplasm. Conversely, AtMYC1 can be recruited into the nucleus by TRY and CPC, concomitant with a strong accumulation of TRY and CPC in the nucleus. When AtMYC1 is targeted to the nucleus or cytoplasm by nuclear localisation or export signals (NLS or NES), respectively, the intracellular localisation of GL1 and TRY also changes accordingly. The biological significance of this intracellular localisation is suggested by the finding that the efficiency of rescue of trichome number is significantly altered in NES and NLS fusions as compared with wild-type AtMYC1. Genetic analysis of mutants and overexpression lines supports the hypothesis that AtMYC1 represses the activity of TRY and CPC.
authors.affiliation: Biocenter, Cologne University, Botanical Institute, Zülpicher Straße 47b, 50674 Cologne, Germany. martin.huelskamp@uni-koeln.de
authors.forename: Martina
authors.initials: M
authors.lastname: Pesch
authors.forename: Ilka
authors.initials: I
authors.lastname: Schultheiß
authors.forename: Simona
authors.initials: S
authors.lastname: Digiuni
authors.forename: Joachim F
authors.initials: JF
authors.lastname: Uhrig
authors.forename: Martin
authors.initials: M
authors.lastname: Hülskamp
mesh_terms: D021581:Active Transport, Cell Nucleus; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D005822:Genetic Vectors; D049790:Nuclear Export Signals; D010641:Phenotype; D059828:Plant Cells / Q000378:metabolism; D019441:Plant Epidermis / Q000235:genetics / Q000378:metabolism; D018515:Plant Leaves / Q000378:metabolism / Q000502:physiology; D030821:Plants, Genetically Modified / Q000235:genetics / Q000378:metabolism; D025941:Protein Interaction Mapping; D020598:Proto-Oncogene Proteins c-myb / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D049790:Nuclear Export Signals; D020598:Proto-Oncogene Proteins c-myb; D014157:Transcription Factors; C103079:ATMYC1 protein, Arabidopsis; C511989:CPC protein, Arabidopsis; C417284:GL3 protein, Arabidopsis; C468526:TRIPTYCHON protein, Arabidopsis; C071556:GL1 protein, Arabidopsis
keywords: Arabidopsis thaliana; GL1; MYC1; Patterning; TRY; Trichome