Biomaterial Database

A plasmocytoma ribosome-associated protein kinase which phosphorylates a specific protein of the ribosomal KCl wash. 1976

C Quirin-Stricker, and M Schmitt, and J M Egly, and J Kempf

One ribosomal protein kinase activity and 3 soluble protein kinase activities have been identified in plasma cell tumors by DEAE-cellulose chromatography. We have shown phosphorylation in vivo and in vitro of a protein fraction from the ribosomal KCl wash which we have termed 'PPx fraction'. Phosphorylation of this protein fraction has been obtained in vitro with the ribosome-associated protein kinase. We have determined for the ribosomal protein kinase the following characteristics. 1. It is an Mg2+-dependent enzyme that transfers the gamma-phosphate from ATP into phosphoseryl and phosphothreonyl residues of the substrate. 2. It has a wide substrate specificity. Like the soluble protein kinases it catalyses the phosphorylation of several proteins like histone, phosvitin, casein and ribosomal proteins but it differs from the main soluble kinases (I, II) by the fact that it catalyses specifically the phosphorylation at least of one of the ribosomal KCl wash proteins. On dodecylsulfate-polyacrylamide gels this protein has a molecular weight of approximately 90000 and it is released from ribosomes under conditions commonly employed for extraction of initiation factors. 3. The ribosome-associated protein kinase is not stimulated by the addition of cyclic adenosine 3':5'-monophosphate. 4. KCl has no effect, NaCl has a weak effect on the phosphorylation, Mn2+ and Ca2+ are inhibitors. 5. ADP has been found to be a competitive inhibitor. 6. The maximum velocity of the ribosomal protein-kinase-catalysed reaction is 0.65 nmol of 32P incorporated in the KCl wash protein per min and per mg protein. 7. The apparent Km for the ribosomal KCl wash protein as substrate is 0.71 mg/ml and the Km for ATP is 94 muM. 8. The molecular weight of the ribosomal protein kinase, estimated by electrophoresis in polyacrylamide-dodecylsulfate gels, is 60000 and corresponds probably to a catalytic subunit.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008274	Magnesium	A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.
D008345	Manganese	A trace element with atomic symbol Mn, atomic number 25, and atomic weight 54.94. It is concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone, influences the synthesis of mucopolysaccharides, stimulates hepatic synthesis of cholesterol and fatty acids, and is a cofactor in many enzymes, including arginase and alkaline phosphatase in the liver. (From AMA Drug Evaluations Annual 1992, p2035)
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009363	Neoplasm Proteins	Proteins whose abnormal expression (gain or loss) are associated with the development, growth, or progression of NEOPLASMS. Some neoplasm proteins are tumor antigens (ANTIGENS, NEOPLASM), i.e. they induce an immune reaction to their tumor. Many neoplasm proteins have been characterized and are used as tumor markers (BIOMARKERS, TUMOR) when they are detectable in cells and body fluids as monitors for the presence or growth of tumors. Abnormal expression of ONCOGENE PROTEINS is involved in neoplastic transformation, whereas the loss of expression of TUMOR SUPPRESSOR PROTEINS is involved with the loss of growth control and progression of the neoplasm.	Proteins, Neoplasm
D010954	Plasmacytoma	Any discrete, presumably solitary, mass of neoplastic PLASMA CELLS either in BONE MARROW or various extramedullary sites.	Plasma Cell Tumor,Plasmocytoma,Plasma Cell Tumors,Plasmacytomas,Plasmocytomas,Tumor, Plasma Cell,Tumors, Plasma Cell
D011189	Potassium Chloride	A white crystal or crystalline powder used in BUFFERS; FERTILIZERS; and EXPLOSIVES. It can be used to replenish ELECTROLYTES and restore WATER-ELECTROLYTE BALANCE in treating HYPOKALEMIA.	Slow-K,Chloride, Potassium
D011494	Protein Kinases	A family of enzymes that catalyze the conversion of ATP and a protein to ADP and a phosphoprotein.	Protein Kinase,Kinase, Protein,Kinases, Protein
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell