Escherichia coliacid phosphatase AphA expression is upregulated under carbon and phosphate starvations and inhibited by CytR

This study investigates the regulation of E. coli aphA expression under nutrient starvation. Using transcriptional reporters with truncated aphA promoter sequences, we found that starvation of carbon and phosphate, but not amino acid, stimulated aphA expression through distinct promoter regions. Deletions of crp or cyaA reduced aphA expression, confirming their importance in aphA regulation during carbon starvation. Conversely, CytR deletion increased aphA expression, suggesting CytR’s role as a repressor of aphA expression. Collectively, these data imply a potential connection between CytR, aphA expression, and the broader context of natural competence evolution and bacterial nutrient absorption.