Nutrient sensing and gene regulation by CodY
Bacteria respond to changes in the nutritional state of their environment by adjusting the expression of genes required for metabolic adaptation, and ultimately, survival. Our interest in this nutritional stress response lead us to study the CodY protein, an amino acid- and GTP-responsive global regulator of many pathways that branch from central metabolism. The protein is produced by nearly all low G+C Gram-positive bacteria; in pathogenic species, CodY also controls virulence gene expression. We determined that S. aureus prioritizes gene expression using CodY, and delays the expression of toxins and other digestive enzymes until CodY activity is substantially reduced. Currently, we are investigating how this delay is genetically wired into the bacterium’s response.