The phosphate regulon and bacterial virulence: a regulatory network connecting phosphate homeostasis and pathogenesis.
Bacterial pathogens regulate virulence factor gene expression coordinately in response to environmental stimuli, including nutrient starvation. The phosphate (Pho) regulon plays a key role in phosphate homeostasis. It is controlled by the PhoR/PhoB two-component regulatory system. PhoR is an integral membrane signaling histidine kinase that, through an interaction with the ABC-type phosphate-specific transport (Pst) system and a protein called PhoU, somehow senses environmental inorganic phosphate (P(i)) levels. Under conditions of P(i) limitation (or in the absence of a Pst component or PhoU), PhoR activates its partner response regulator PhoB by phosphorylation, which, in turn, up- or down-regulates target genes. Single-cell profiling of PhoB activation has shown recently that Pho regulon gene expression exhibits a stochastic, "all-or-none" behavior. Recent studies have also shown that the Pho regulon plays a role in the virulence of several bacteria. Here, we present a comprehensive overview of the role of the Pho regulon in bacterial virulence. The Pho regulon is clearly not a simple regulatory circuit for controlling phosphate homeostasis; it is part of a complex network important for both bacterial virulence and stress response.
Lamarche
Martin G
MG
Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de médecine vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec, Canada.
Wanner
Barry L
BL
Crépin
Sébastien
S
Harel
Josée
J
D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D018407:Bacterial Physiological Phenomena; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D018441:Biofilms / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D006706:Homeostasis; D010710:Phosphates / Q000378:metabolism*; D018085:Regulon; D014774:Virulence
D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; D010710:Phosphates; C061278:PhoB protein, Bacteria; C061279:PhoR protein, Bacteria