title: The regulatory α and β subunits of phosphorylase kinase directly interact with its substrate, glycogen phosphorylase.
abstract: The selective phosphorylation of glycogen phosphorylase (GP) by its only known kinase, phosphorylase kinase (PhK), keeps glycogen catabolism tightly regulated. In addition to the obligatory interaction between the catalytic γ subunit of PhK and the phosphorylatable region of GP, previous studies have suggested additional sites of interaction between this kinase and its protein substrate. Using short chemical crosslinkers, we have identified direct interactions of GP with the large regulatory α and β subunits of PhK. These newfound interactions were found to be sensitive to ligands that bind PhK.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA.
authors.forename: Jackie A
authors.initials: JA
authors.lastname: Thompson
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA. Electronic address: gcarlson@kumc.edu.
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Carlson
mesh_terms: D001665:Binding Sites; D003432:Cross-Linking Reagents / Q000737:chemistry; D004789:Enzyme Activation; D024981:Glycogen Phosphorylase / Q000737:chemistry* / Q000648:ultrastructure; D009097:Multienzyme Complexes / Q000737:chemistry / Q000648:ultrastructure; D010764:Phosphorylase Kinase / Q000737:chemistry* / Q000648:ultrastructure; D011485:Protein Binding; D025941:Protein Interaction Mapping / Q000379:methods*; D021122:Protein Subunits; D013379:Substrate Specificity
chemical_list: D003432:Cross-Linking Reagents; D009097:Multienzyme Complexes; D021122:Protein Subunits; D024981:Glycogen Phosphorylase; D010764:Phosphorylase Kinase
keywords: Crosslinking; Docking sites; Glycogen phosphorylase; Phosphorylase kinase; Substrate recognition