title: How tyrosine phosphorylation affects the UDP-glucose dehydrogenase activity of Bacillus subtilis YwqF.
abstract: The UDP-glucose dehydrogenase activity of Bacillus subtilis YwqF is regulated by reversible phosphorylation on a tyrosine residue. This reaction, which is catalyzed by the protein-tyrosine kinase YwqD, activates the enzyme, while dephosphorylation of phosphotyrosine-YwqF by the phosphotyrosine-protein phosphatase YwqE reduces its enzyme activity. Our kinetic data indicate that the phosphorylated and unphosphorylated forms of YwqF differ in binding the substrates. The UDP-glucose dehydrogenase reaction catalyzed by YwqF is inhibited by one of its substrates, UDP-glucose, and the extent of this inhibition seems to be reduced upon YwqF phosphorylation. We propose that this effect could at least partly account for the observed activation of YwqF induced by tyrosine phosphorylation. Potential physiological implications of this finding are discussed.
authors.affiliation: Microbiologie et Génétique Moléculaire, CNRS/INRA/INA-PG UMR 2585, Thiverval-Grignon, France. im@biocentrum.tu.dk
authors.forename: Ivan
authors.initials: I
authors.lastname: Mijakovic
authors.forename: Dina
authors.initials: D
authors.lastname: Petranovic
authors.forename: Josef
authors.initials: J
authors.lastname: Deutscher
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009243:NAD / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014443:Tyrosine / Q000378:metabolism*; D014533:Uridine Diphosphate Glucose Dehydrogenase / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D009243:NAD; D014443:Tyrosine; D014533:Uridine Diphosphate Glucose Dehydrogenase; D011505:Protein-Tyrosine Kinases; D010744:Phosphoric Monoester Hydrolases