Steady-state hydrogen peroxide induces glycolysis in Staphylococcus aureus and Pseudomonas aeruginosa

Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from human pathogens Staphylococcus aureus and Pseudomonas aeruginosa can be readily inhibited by reactive oxygen species (ROS)-mediated direct oxidation of their catalytic active cysteines. Because of the rapid degradation of H2O2 by bacterial catalase, only steady-state but not one-dose treatment with H2O2 rapidly induces glycolysis and the pentose phosphate pathway (PPP). We conducted transcriptome sequencing (RNA-seq) analyses to globally profile the bacterial transcriptomes in response to a steady level of H2O2, which revealed profound transcriptional changes, including the induced expression of glycolytic genes in both bacteria. Our results revealed that the inactivation of GAPDH by H2O2 induces metabolic levels of glycolysis and the PPP; the elevated levels of fructose 1,6-biphosphate (FBP) and 2-keto-3-deoxy-6-phosphogluconate (KDPG) lead to dissociation of their corresponding glycolytic repressors (GapR and HexR, respectively) from their cognate promoters, thus resulting in derepression of the glycolytic genes to overcome H2O2-stalled glycolysis in S. aureus and P. aeruginosa, respectively. Both GapR and HexR may directly sense oxidative stresses, such as menadione.