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cAMP‐dependent phosphorylation activates phosphofructokinase from mantle tissue of the mollusc Mytilus galloprovincialis. Identification of the phosphorylated site
Author(s) -
Fernández Montserrat,
Cao Jesús,
Vega Félix V.,
Hellman Ulf,
Wernstedt Christer,
Villamarín J. Antonio
Publication year - 1997
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549700203941
Subject(s) - phosphofructokinase , phosphorylation , mytilus , biochemistry , protein kinase a , biology , kinase , glycolysis , protein subunit , allosteric regulation , phosphopeptide , microbiology and biotechnology , enzyme , gene , ecology
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.