Biomaterial Database

The Escherichia coli adenylate cyclase complex. Stimulation by potassium and phosphate. 1985

E Liberman, and P Reddy, and C Gazdar, and A Peterkofsky

In Escherichia coli, adenylate cyclase activity in toluene-treated cells can be inhibited by glucose while the activity in a broken cell preparation cannot. Adenylate cyclase activity in the permeabilized but not in broken cells is stimulated somewhat specifically and additively by potassium and phosphate. Kinetic studies show sigmoid substrate-velocity curves for the toluene-treated cells but hyperbolic curves for the broken cells. The stimulatory effects of potassium and phosphate on adenylate cyclase activity in tolulene-treated cells are associated with increases in the Vmax and Km for ATP. While the enzyme activity in toluene-treated cells shows a preference for magnesium over manganese, the reverse is observed in broken cells. Stimulation of adenylate cyclase activity in toluene-treated cells requires the presence of the proteins of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). The PTS proteins can be phosphorylated in a P-enolpyruvate-dependent reaction. The stimulatory effects of ions will not occur if the PTS proteins are not phosphorylated. Since potassium phosphate stimulates both adenylate cyclase and PTS activities in toluene-treated cells, it is proposed that the effect of potassium phosphate on adenylate cyclase activity is mediated through an effect on the PTS. A model for dual regulation by glucose of adenylate cyclase activity is proposed. This model involves regulation of both the condition of the PTS proteins as well as the cellular concentration of phosphate.

UI	MeSH Term	Description	Entries
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)
D008956	Models, Chemical	Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.	Chemical Models,Chemical Model,Model, Chemical
D010539	Permeability	Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.	Permeabilities
D010710	Phosphates	Inorganic salts of phosphoric acid.	Inorganic Phosphate,Phosphates, Inorganic,Inorganic Phosphates,Orthophosphate,Phosphate,Phosphate, Inorganic
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D004926	Escherichia coli	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.	Alkalescens-Dispar Group,Bacillus coli,Bacterium coli,Bacterium coli commune,Diffusely Adherent Escherichia coli,E coli,EAggEC,Enteroaggregative Escherichia coli,Enterococcus coli,Diffusely Adherent E. coli,Enteroaggregative E. coli,Enteroinvasive E. coli,Enteroinvasive Escherichia coli
D000262	Adenylyl Cyclases	Enzymes of the lyase class that catalyze the formation of CYCLIC AMP and pyrophosphate from ATP.	Adenyl Cyclase,Adenylate Cyclase,3',5'-cyclic AMP Synthetase,Adenylyl Cyclase,3',5' cyclic AMP Synthetase,AMP Synthetase, 3',5'-cyclic,Cyclase, Adenyl,Cyclase, Adenylate,Cyclase, Adenylyl,Cyclases, Adenylyl,Synthetase, 3',5'-cyclic AMP