Transcriptome analysis of phosphate starvation response in Escherichia coli.
Escherichia coli has a PhoR-PhoB two-component regulatory system to detect and respond to the changes of environmental phosphate concentration. For the E. coli W3110 strain growing under phosphate-limiting condition, the changes of global gene expression levels were investigated by using DNA microarray analysis. The expression levels of some genes that are involved in phosphate metabolism were increased as phosphate became limited, whereas those of the genes involved in ribosomal protein or amino acid metabolism were decreased, owing to the stationary phase response. The upregulated genes could be divided into temporarily and permanently inducible genes by phosphate starvation. At the peak point showing the highest expression levels of the phoB and phoR genes under phosphate-limiting condition, the phoB- and/or phoR-dependent regulatory mechanisms were investigated in detail by comparing the gene expression levels among the wild-type and phoB and/or phoR mutant strains. Overall, the phoB mutation was epistatic over the phoR mutation. It was found that PhoBR and PhoB were responsible for the upregulation of the phosphonate or glycerol phosphate metabolism and high-affinity phosphate transport system, respectively. These results show the complex regulation by the PhoR-PhoB two-component regulatory system in E. coli.
Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Program) and BioProcess Engineering Research Center, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
Jong Hwan
JH
Baek
Sang Yup
SY
Lee
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000502:physiology; D001483:Base Sequence; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010710:Phosphates / Q000378:metabolism*
D001426:Bacterial Proteins; D010710:Phosphates; C061278:PhoB protein, Bacteria; C061279:PhoR protein, Bacteria