title: Phosphocreatine-dependent protein phosphorylation in rat skeletal muscle.
abstract: Phosphocreatine (PCr) was found to alter the phosphorylation state of two proteins of apparent molecular masses 18 and 29 kDa in dialysed cell-free extracts of rat skeletal muscle in the presence of [gamma-32P]ATP. The 29 kDa protein was identified as phosphoglycerate mutase (PGM), phosphorylated at the active-site histidine residue by 2,3-bisphosphoglycerate (2,3-biPG). 2,3-biPG labelling from [gamma-32P]ATP occurred through the concerted action of phosphoglycerate kinase and 2,3-bisphosphoglycerate mutase. PCr-dependent labelling, which required creatine kinase, resulted from a shift in the phosphoglycerate kinase equilibrium towards 1,3-bisphosphoglycerate (1,3-biPG) synthesis, ultimately resulting in an increase in available [2-32P]2,3-biPG. The maximal catalytic activity of PGM was unaffected by PCr. The 18 kDa protein was transiently phosphorylated at a histidine residue, probably by 1,3-biPG. No proteins of this monomeric molecular mass are known to bind 1,3-biPG, suggesting that the 18 kDa protein is an undescribed phosphoenzyme intermediate. Previous observations of 2- and 3-phosphoglycerate-dependent protein phosphorylation in cytosolic extracts [Ueda & Plagens (1987) Proc. Natl. Acad. Sci. U.S.A. 84, 1229-1233; Pek, Usami, Bilir, Fischer-Bovenkerk & Ueda (1990) Proc. Natl. Acad. Sci. U.S.A. 87, 4294-4298], attributed to the action of novel kinases, are likely to represent phosphoenzyme intermediates labelled by bisphosphorylated metabolites in a similar manner.
authors.affiliation: Montreal Neurological Institute, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Ouellet
authors.forename: E A
authors.initials: EA
authors.lastname: Shoubridge
mesh_terms: D019794:2,3-Diphosphoglycerate; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D001731:Bisphosphoglycerate Mutase / Q000378:metabolism; D003402:Creatine Kinase / Q000378:metabolism; D003600:Cytosol / Q000201:enzymology / Q000378:metabolism; D004163:Diphosphoglyceric Acids / Q000378:metabolism; D006639:Histidine / Q000378:metabolism; D007700:Kinetics; D008297:Male; D008970:Molecular Weight; D009124:Muscle Proteins / Q000378:metabolism*; D009132:Muscles / Q000201:enzymology / Q000378:metabolism*; D010725:Phosphocreatine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D010735:Phosphoglycerate Kinase / Q000378:metabolism; D010736:Phosphoglycerate Mutase / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004163:Diphosphoglyceric Acids; D009124:Muscle Proteins; D010761:Phosphorus Radioisotopes; D010725:Phosphocreatine; D019794:2,3-Diphosphoglycerate; C015891:glycerate 1,3-biphosphate; D006639:Histidine; C025403:phosphocreatinine; D000255:Adenosine Triphosphate; D010735:Phosphoglycerate Kinase; D003402:Creatine Kinase; D010736:Phosphoglycerate Mutase; D001731:Bisphosphoglycerate Mutase