Cytoplasmic Mg²⁺ supersedes carbon source preference to dictate <i>Salmonella</i> metabolism.

ABSTRACT: Glucose is the preferred carbon source of most studied microorganisms. However, we now report that glucose loses preferred status when the intracellular pathogen Salmonella enterica serovar Typhimurium experiences cytoplasmic magnesium (Mg²⁺) starvation. We establish that this infection-relevant stress drastically reduces synthesis of cyclic adenosine monophosphate (cAMP), the allosteric activator of the cAMP receptor protein (CRP), master regulator of carbon utilization. The resulting reduction in cAMP concentration, which is independent of carbon source, decreases transcription of CRP-cAMP-activated carbon utilization genes, hinders carbon source uptake, and restricts metabolism, rendering wild-type bacteria phenotypically CRP^-. A cAMP-independent allele of C

SUBMITTER: Pokorzynski ND 

PROVIDER: S-EPMC12002343 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature