GLUTAMINE AND REGULATION OF GENE-EXPRESSION IN MAMMALIAN-CELLS - SPECIAL REFERENCE TO PHOSPHOENOLPYRUVATE CARBOXYKINASE (PEPCK)

The repertoire of the actions of specific amino acids on gene expressi on is relatively limited in mammalian cells. Glutamine constitutes the most studied amino acid and recent works intended to demonstrate its mechanism of action on two genes: the beta-actin and the phosphoenolpy ruvate carboxykinase genes. From these studies, it appears that glutam ine may regulate gene expression by, at least, two different mechanism s: one through the glutamine-induced cell swelling, and another throug h its intracellular metabolism. The involvement of phosphatidylinosito l 3-kinase in the signaling pathway triggered by cell swelling is disc ussed.