title: Existence of a plant tyrosylprotein sulfotransferase: novel plant enzyme catalyzing tyrosine O-sulfation of preprophytosulfokine variants in vitro.
abstract: An in vitro assay system to detect tyrosylprotein sulfotransferase (TPST) activity of higher plant cells was established, using synthetic oligopeptides based on the deduced amino acid sequence of a phytosulfokine-alpha (PSK-alpha) precursor. TPST activity was found in microsomal membrane fractions of rice, asparagus and carrot cells and it was confirmed that acidic amino acid residues adjacent to the tyrosine residues of acceptor peptides were essential to the sulfation reaction. The asparagus TPST exhibited a broad pH optimum of 7.0-8.5, required manganese ions for maximal activity and appeared to be a membrane-bound protein localized in the Golgi apparatus. These enzymes should be defined as a new class of plant sulfotransferases that catalyze tyrosine O-sulfation of a PSK-alpha precursor and other unknown proteins.
authors.affiliation: Laboratory of Bioactive Natural Products Chemistry, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan. i983006d@mbox.media.nagoya-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Hanai
authors.forename: D
authors.initials: D
authors.lastname: Nakayama
authors.forename: H
authors.initials: H
authors.lastname: Yang
authors.forename: Y
authors.initials: Y
authors.lastname: Matsubayashi
authors.forename: Y
authors.initials: Y
authors.lastname: Hirota
authors.forename: Y
authors.initials: Y
authors.lastname: Sakagami
mesh_terms: D000595:Amino Acid Sequence; D002384:Catalysis / Q000187:drug effects; D002413:Cations, Divalent / Q000494:pharmacology; D002460:Cell Line; D014644:Genetic Variation / Q000235:genetics*; D006056:Golgi Apparatus / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008345:Manganese / Q000494:pharmacology; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism; D008861:Microsomes / Q000201:enzymology; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D036361:Peptide Hormones; D059828:Plant Cells; D010937:Plant Growth Regulators; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D013379:Substrate Specificity; D015238:Sulfotransferases / Q000302:isolation & purification / Q000378:metabolism*; D013455:Sulfur / Q000378:metabolism*; D013816:Thermodynamics; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D002413:Cations, Divalent; D008565:Membrane Proteins; C100975:PSK-alpha protein, plant; D010446:Peptide Fragments; D036361:Peptide Hormones; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011498:Protein Precursors; D014443:Tyrosine; D008345:Manganese; D013455:Sulfur; D015238:Sulfotransferases; C039079:protein-tyrosine sulfotransferase