Disease relevance of barA

• The barA and sirA genes of Salmonella enterica serovar Typhimurium encode a two-component sensor kinase and a response regulator, respectively [1].

High impact information on barA

• Two other short-chain fatty acids (SCFA), propionate and butyrate, present in high concentrations in the caecum and colon, had effects opposite to those of acetate: neither restored invasion gene expression in the barA mutant, and both, in fact, reduced expression in the wild-type strain [2].
• Further, a combination of SCFAs found in the distal ileum restored invasion gene expression in the barA mutant, whereas colonic conditions failed to do so and also reduced expression in the wild-type strain [2].
• Response regulators are activated to elicit a specific cellular response to an extracellular stimulus via phosphotransfer from a cognate sensor histidine kinase to a specific aspartate residue [3].

Associations of barA with chemical compounds

• These results suggest that the rising concentration of acetate in the distal ileum provides a signal for invasion gene expression by the production of acetyl-phosphate in the bacterial cytoplasm, a pathway that bypasses barA [2].

References