Global regulation by the seven-component Pi signaling system

Curr Opin Microbiol. 2010 Apr;13(2):198-203. doi: 10.1016/j.mib.2010.01.014. Epub 2010 Feb 18.


This review concerns how Escherichia coli detects environmental inorganic orthophosphate (P(i)) to regulate genes of the phosphate (Pho) regulon by the PhoR/PhoB two-component system (TCS). P(i) control by the PhoR/PhoB TCS is a paradigm of a bacterial signal transduction pathway in which occupancy of a cell surface receptor(s) controls gene expression in the cytoplasm. The P(i) signaling pathway requires seven proteins, all of which probably interact in a membrane-associated signaling complex. Our latest studies show that P(i) signaling involves three distinct processes, which appear to correspond to different states of the sensory histidine kinase PhoR: an inhibition state, an activation state, and a deactivation state. We describe a revised model for P(i) signal transduction of the E. coli Pho regulon.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Escherichia coli / genetics
  • Escherichia coli / metabolism*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Phosphates / metabolism*
  • Regulon
  • Signal Transduction*


  • Bacterial Proteins
  • Escherichia coli Proteins
  • Phosphates
  • PhoB protein, Bacteria
  • PhoR protein, Bacteria