Fe3+-dependent epistasis between the CpxR-activated loci and the PmrA-activated LPS modification loci in Salmonella enterica.
Bacteria utilize varying combinations of two-component regulatory systems, many of which respond and adapt closely to stress conditions, thus expanding their niche steadily. While mechanisms of recognition and avoidance of the specific Fe3+signal by the PmrA/PmrB system is well understood, those of the CpxR/CpxA system are more complex because they can be induced by various stress conditions, which, in turn, expresses a variety of phenotypes. Here, we highlight another aspect of the CpxR/CpxA system; mutations in degP and yqjA genes, which are under the control of the system, exhibit an iron sensitive phenotype in the mutant background defective in the PmrA-dependent gene products that alter the pyrophosphate status of the lipid A moiety of lipopolysaccharide in Salmonella enterica. Therefore, after the PmrA/PmrB-mediated Fe3+-dependent control of the pyrophosphate status on the cell surface, the CpxR/CpxA system is one of the second layers of envelope stress response that allows adaptation to high Fe3+conditions in this bacterium.
Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University.
Akinori
A
Kato
Nami
N
Higashino
Ryutaro
R
Utsumi
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004843:Epistasis, Genetic; D005290:Ferric Compounds / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D056426:Genetic Loci; D006360:Heat-Shock Proteins / Q000235:genetics; D008070:Lipopolysaccharides / Q000737:chemistry*; D009154:Mutation; D033903:Periplasmic Proteins / Q000235:genetics; D017382:Reactive Oxygen Species / Q000378:metabolism; D012486:Salmonella typhimurium / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000235:genetics; D013312:Stress, Physiological; D014774:Virulence
D001426:Bacterial Proteins; D005290:Ferric Compounds; D006360:Heat-Shock Proteins; D008070:Lipopolysaccharides; D033903:Periplasmic Proteins; D017382:Reactive Oxygen Species; C081902:pmrA protein, Bacteria; C085504:CpxR protein, Bacteria; C061682:DegP protease; D012697:Serine Endopeptidases