Induction of protein phosphorylation, protein synthesis, immediate-early-gene expression and cellular proliferation by intracellular pH modulation : implications for the role of hydrogen ions in signal transduction

• Published in: European journal of biochemistry Vol. 213; no. 1; pp. 349 - 357
• Main Authors: ISFORT, R. J, CODY, D. B, ASQUITH, T. N, RIDDER, G. M, STUARD, S. B, LEBOEUF, R. A
• Format: Journal Article
• Language: English
• Published: Oxford Blackwell 01-04-1993
• Subjects: Animals; Biological and medical sciences; Calcium - metabolism; Cell Division; Cell physiology; Cells, Cultured; Cricetinae; Effects of physical and chemical agents; Epidermal Growth Factor - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Gene Expression; Genes, fos; Genes, myc; Hydrogen - physiology; Hydrogen-Ion Concentration; Ions; Molecular and cellular biology; Phosphorylation; Pregnancy; Protein Biosynthesis; Proteins - genetics; Proteins - metabolism; Signal Transduction - physiology; Cell proliferation; Phosphorylation; Rodentia; Gene expression; Signal transduction; Vertebrata; Mammalia; Epidermal growth factor; Polypeptide; Protein synthesis; pH; Early; Intracellular; Hamster; Growth factor
• ISSN: 0014-2956; 1432-1033
• DOI: 10.1111/j.1432-1033.1993.tb17768.x

In Syrian hamster embryo cells, intracellular acidification (but not alkalization) results in proliferation, immediate-early-gene expression and tyrosine phosphorylation. In addition, both intracellular acidification and alkalization result in serine/threonine phosphorylation and de novo protein synthesis of specific proteins. Calcium is not mobilized in response to either intracellular alkalization or acidification. Neither intracellular acidification nor alkalization altered the serum proliferative signal while intracellular alkalization (but not acidification) reduced the epidermal-growth-factor-induced proliferative signal, tyrosine phosphorylation and immediate-early-gene expression. Finally, intracellular acidification (but not alkalization) could induce immediate-early-gene expression in cells growing in the presence of serum, indicating that the pH signalling pathway is not down modulated by the serum signalling pathway. These results, while indirect, indicate that hydrogen ions may play an important role in mitogen-signal transduction in Syrian hamster embryo cells.