Two-component PhoB-PhoR regulatory system and ferric uptake regulator sense phosphate and iron to control virulence genes in type III and VI secretion systems of Edwardsiella tarda.

ABSTRACT: Inorganic phosphate (P(i)) and iron are essential nutrients that are depleted by vertebrates as a protective mechanism against bacterial infection. This depletion, however, is sensed by some pathogens as a signal to turn on the expression of virulence genes. Here, we show that the PhoB-PhoR two-component system senses changes in P(i) concentration, whereas the ferric uptake regulator (Fur) senses changes in iron concentration in Edwardsiella tarda PPD130/91 to regulate the expression of type III and VI secretion systems (T3SS and T6SS) through an E. tarda secretion regulator, EsrC. In sensing low P(i) concentration, PhoB-PhoR autoregulates and activates the phosphate-specific transport operon, pstSCAB-phoU, by binding directly to the Pho box in the promoters of phoB and pstS. PhoB also bin

SUBMITTER: Chakraborty S 

PROVIDER: S-EPMC3234765 | biostudies-literature | 2011 Nov

REPOSITORIES: biostudies-literature