title: A conserved dibasic site is essential for correct processing of the peptide hormone AtRALF1 in Arabidopsis thaliana.
abstract: Prohormone proteins in animals and yeast are typically processed at dibasic sites by convertases. Propeptide hormones are also found in plants but little is known about processing. We show for the first time that a dibasic site upstream of a plant peptide hormone, AtRALF1, is essential for processing. Overexpression of preproAtRALF1 causes semi-dwarfism whereas overexpression of preproAtRALF1(R69A), the propeptide with a mutation in the dibasic site, shows a normal phenotype. RALF1(R69A) plants accumulate only the mutated proprotein and not the processed peptide. In vitro processing using microsomal fractions suggests that processing is carried out by a kexin-like convertase.
authors.affiliation: Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo,C.P. 83, 13400-970 Piracicaba, SP, Brazil.
authors.forename: Juliana L
authors.initials: JL
authors.lastname: Matos
authors.forename: Celso S
authors.initials: CS
authors.lastname: Fiori
authors.forename: Marcio C
authors.initials: MC
authors.lastname: Silva-Filho
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Moura
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D017360:Arabidopsis / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001120:Arginine / Q000235:genetics / Q000378:metabolism*; D002458:Cell Fractionation; D017124:Conserved Sequence / Q000235:genetics; D008861:Microsomes / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D036361:Peptide Hormones / Q000235:genetics / Q000378:metabolism*; D018515:Plant Leaves / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism; D014170:Transformation, Genetic
chemical_list: D029681:Arabidopsis Proteins; D036361:Peptide Hormones; C529880:RALF1 protein, Arabidopsis; D001120:Arginine