title: G-protein-coupled receptor 1, G-protein Galpha-subunit 1, and prephenate dehydratase 1 are required for blue light-induced production of phenylalanine in etiolated Arabidopsis.
abstract: Different classes of plant hormones and different wavelengths of light act through specific signal transduction mechanisms to coordinate higher plant development. A specific prephenate dehydratase protein (PD1) was discovered to have a strong interaction with the sole canonical G-protein Galpha-subunit (GPA1) in Arabidopsis (Arabidopsis thaliana). PD1 is a protein located in the cytosol, present in etiolated seedlings, with a specific role in blue light-mediated synthesis of phenylpyruvate and subsequently of phenylalanine (Phe). Insertion mutagenesis confirms that GPA1 and the sole canonical G-protein-coupled receptor (GCR1) in Arabidopsis also have a role in this blue light-mediated event. In vitro analyses indicate that the increase in PD1 activity is the direct and specific consequence of its interaction with activated GPA1. Because of their shared role in the light-mediated synthesis of phenylpyruvate and Phe, because they are iteratively interactive, and because activated GPA1 is directly responsible for the activation of PD1; GCR1, GPA1, and PD1 form all of or part of a signal transduction mechanism responsible for the light-mediated synthesis of phenylpyruvate, Phe, and those metabolites that derive from that Phe. Data are also presented to confirm that abscisic acid can act through the same pathway. An additional outcome of the work is the confirmation that phenylpyruvate acts as the intermediate in the synthesis of Phe in etiolated plants, as it commonly does in bacteria and fungi.
authors.affiliation: Laboratory for Molecular Biology, Department of Biological Sciences, University of Illinois, Chicago, 60607, USA.
authors.forename: Katherine Mary
authors.initials: KM
authors.lastname: Warpeha
authors.forename: Syed Salman
authors.initials: SS
authors.lastname: Lateef
authors.forename: Yevgeniya
authors.initials: Y
authors.lastname: Lapik
authors.forename: Marybeth
authors.initials: M
authors.lastname: Anderson
authors.forename: Bao-Shiang
authors.initials: BS
authors.lastname: Lee
authors.forename: Lon Seth
authors.initials: LS
authors.lastname: Kaufman
mesh_terms: D000595:Amino Acid Sequence; D000872:Anthocyanins / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism; D044385:GTP-Binding Protein alpha Subunits / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D008027:Light; D045342:Light-Harvesting Protein Complexes / Q000235:genetics / Q000378:metabolism; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010649:Phenylalanine / Q000096:biosynthesis*; D011302:Prephenate Dehydratase / Q000235:genetics / Q000502:physiology*; D025941:Protein Interaction Mapping; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism
chemical_list: D000872:Anthocyanins; D029681:Arabidopsis Proteins; C112029:GCR1 protein, Arabidopsis; C429765:GPA1 protein, Arabidopsis; D044385:GTP-Binding Protein alpha Subunits; D045342:Light-Harvesting Protein Complexes; D043562:Receptors, G-Protein-Coupled; D014443:Tyrosine; D010649:Phenylalanine; D011302:Prephenate Dehydratase