The induction of ornithine decarboxylase by L-asparagine and intracellular alkalinization.
The uptake of transport systems A and N amino acids, most noticeably L-asparagine, is essential for the induction of ornithine decarboxylase (L-ornithine carboxylase, EC 4.1.1.17) in cultured cells and we have proposed that the uptake-associated pH and ionic changes might constitute part of the cell activation signal (1). In the present study, it was shown that extracellular L-asparagine caused an immediate and transient increase in intracellular pH which was continuously monitored by the fluorescence probe BCECF (2',7'-bis(carboxyethyl)-5,6-carboxyfluorescein). NH4Cl and NH4OH which caused intracellular alkalinization also caused ornithine decarboxylase activity to increase.
Fong
W F
WF
Department of Biochemistry, Faculty of Medicine, University of Hong Kong.
Law
C L
CL
D000643:Ammonium Chloride / Q000494:pharmacology*; D001216:Asparagine / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000201:enzymology*; D004790:Enzyme Induction; D006863:Hydrogen-Ion Concentration; D007424:Intracellular Fluid / Q000378:metabolism; D008113:Liver Neoplasms; D009955:Ornithine Decarboxylase / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D000643:Ammonium Chloride; D001216:Asparagine; D009955:Ornithine Decarboxylase