title: cAMP-dependent phosphorylation activates phosphofructokinase from mantle tissue of the mollusc Mytilus galloprovincialis. Identification of the phosphorylated site.
abstract: Phosphofructokinase from mantle tissue of the sea mussel Mytilus galloprovincialis was phosphorylated in vitro by a protein kinase isolated from the same tissue, homologous to mammalian cAMP-dependent protein kinase; the maximal level of phosphorylation achieved was around 1 mol of Pi/mol of phosphofructokinase subunit. The covalent incorporation of phosphate leads to a notable increase in the enzyme activity assayed at near-physiological concentrations of substrates and allosteric modulators and neutral pH. Tryptic digestion of labeled phosphofructokinase released a phosphopeptide whose sequence was Lys-Asp-Ser(P)-Ile-Trp-Ile-Gln-Thr-Gly-Arg. This sequence showed high homology with the phosphopeptides from other invertebrates whose phosphofructokinase is also activated by cAMP-dependent phosphorylation.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Santiago de Compostela, Lugo, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Fernández
authors.forename: J
authors.initials: J
authors.lastname: Cao
authors.forename: F V
authors.initials: FV
authors.lastname: Vega
authors.forename: U
authors.initials: U
authors.lastname: Hellman
authors.forename: C
authors.initials: C
authors.lastname: Wernstedt
authors.forename: J A
authors.initials: JA
authors.lastname: Villamarín
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D049872:Bivalvia / Q000201:enzymology*; D000242:Cyclic AMP / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D010732:Phosphofructokinase-1 / Q000737:chemistry / Q000378:metabolism*; D010748:Phosphopeptides / Q000378:metabolism; D010766:Phosphorylation
chemical_list: D010748:Phosphopeptides; D000242:Cyclic AMP; D010732:Phosphofructokinase-1; D017868:Cyclic AMP-Dependent Protein Kinases