title: COI1 links jasmonate signalling and fertility to the SCF ubiquitin-ligase complex in Arabidopsis.
abstract: Jasmonates (JAs) regulate Arabidopsis thaliana wound and defence responses, pollen development, and stress-related growth inhibition. Significantly, each of these responses requires COI1, an F-box protein. Other F-box proteins interact with SKP1 and cullin proteins to form SCF complexes that selectively recruit regulatory proteins targeted for ubiquitination. To determine whether COI1 also functions in an SCF complex, we have characterized Arabidopsis proteins that bind to COI1. An Arabidopsis cDNA expression library was screened in yeast for clones that produce proteins which can bind to COI1. We recovered two SKP1 homologues and a histone deacetylase. The Arabidopsis F-box protein TIR1 interacted with SKP1 proteins, but not with the histone deacetylase. Mutant COI1 proteins revealed that the F-box is required for interaction with SKP1s, but that sequences in leucine-rich repeat domains are required for interaction with the histone deacetylase. Epitope-tagged COI1 was introduced into Arabidopsis plants and cell cultures. Co-immunoprecipitation experiments confirmed the interaction in planta of COI1 with SKP1-like proteins and histone deacetylase, and also indicated that COI1 interacted with cullin. These results suggest that COI1 forms an SCFCOI1 complex in vivo. COI1 is therefore expected to form a functional E3-type ubiquitin ligase in plants and to regulate expression of jasmonate responsive genes, possibly by targeted ubiquitination of a histone deacetylase.
authors.affiliation: School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK, and John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Devoto
authors.forename: Manuela
authors.initials: M
authors.lastname: Nieto-Rostro
authors.forename: Daoxin
authors.initials: D
authors.lastname: Xie
authors.forename: Christine
authors.initials: C
authors.lastname: Ellis
authors.forename: Rebecca
authors.initials: R
authors.lastname: Harmston
authors.forename: Elaine
authors.initials: E
authors.lastname: Patrick
authors.forename: Jackie
authors.initials: J
authors.lastname: Davis
authors.forename: Leigh
authors.initials: L
authors.lastname: Sherratt
authors.forename: Mark
authors.initials: M
authors.lastname: Coleman
authors.forename: John G
authors.initials: JG
authors.lastname: Turner
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003517:Cyclopentanes / Q000378:metabolism*; D005298:Fertility; D017343:Genes, Plant / Q000235:genetics; D006655:Histone Deacetylases / Q000235:genetics / Q000378:metabolism; D008540:Meiosis; D008969:Molecular Sequence Data; D009154:Mutation; D054883:Oxylipins; D010453:Peptide Synthases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D011485:Protein Binding; D021122:Protein Subunits; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012273:Ribulose-Bisphosphate Carboxylase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D044843:SKP Cullin F-Box Protein Ligases; D012441:Saccharomyces cerevisiae; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; C112279:COI1 protein, Arabidopsis; D003517:Cyclopentanes; D054883:Oxylipins; D021122:Protein Subunits; D012097:Repressor Proteins; C011006:jasmonic acid; D044843:SKP Cullin F-Box Protein Ligases; D006655:Histone Deacetylases; D012273:Ribulose-Bisphosphate Carboxylase; D010453:Peptide Synthases