REDOX-REGULATED EXPRESSION OF GLYCOLYTIC-ENZYMES IN RESTING AND PROLIFERATING RAT THYMOCYTES

Resting rat thymocytes partially degrade glucose aerobically to CO2 an d H2O and produce reactive peroxide anions, In contrast proliferating cells, due to enhanced induction of glycolytic enzymes, degrade glucos e almost completely to lactate thus minimizing the production of react ive oxygen species. In this paper we show that under conditions of oxi dative stress the induction of the glycolytic enzymes in cultured rat thymocytes is markedly reduced. Furthermore, transfection assays with a rat hepatoma cell line and Drosophila Schneider cells revealed that reactive oxygen intermediates dramatically decrease the transcriptiona l activities of the Sp1-dependent aldolase A and pyruvate kinase M(2) promoters leading to reduced reporter gene expression. These results i ndicate that cellular redox changes can regulate gene expression by re versible oxidative inactivation of Sp1 binding. (C) 1997 Federation of European Biochemical Societies.