The phosphate-starvation response in Vibrio cholerae O1 and phoB mutant under proteomic analysis: disclosing functions involved in adaptation, survival and virulence.
A proteomic analysis of a wild-type and of a phoB mutant showed that Vibrio cholerae expresses genes of two major regulons in response to phosphate starvation. The Pho regulon, expressed by the wild-type, allowed the cells to adapt to the new environment. Induction of the general stress regulon was mainly observed in the phoB mutant as a strategy to resist stress and survive. Some functions of the adaptative and survival responses play roles in the pathogenicity of the bacteria. Among the members of the Pho regulon, we found a porin described as an important factor for the intestinal colonisation. Other functions not obviously related to phosphate metabolism, expressed preferentially by the wild-type cells, have also been implicated in virulence. These findings might explain the lack of virulence of the phoB mutant. The Pho regulon picture of V. cholerae, however, will not be complete until minor members and membrane proteins are identified. Among the phosphate-starvation induced genes we have found 13 hypothetical ones and for some of them functions have been assigned. The majority of the genes identified here have not been described before, thus they could be used to expand the proteomic reference map of V. cholerae El Tor.
von Krüger
Wanda Maria Almeida
WM
Proteomics Network of Rio de Janeiro-FAPERJ, Rio de Janeiro, Brazil. wmavk@biof.ufrj.br
Lery
Leticia Miranda Santos
LM
Soares
Marcia Regina
MR
de Neves-Manta
Fernanda Saloum
FS
Batista e Silva
Celia Maria
CM
Neves-Ferreira
Ana Gisele da Costa
AG
Perales
Jonas
J
Bisch
Paulo Mascarello
PM
D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D015180:Electrophoresis, Gel, Two-Dimensional; D008969:Molecular Sequence Data; D009876:Operon; D010710:Phosphates / Q000378:metabolism*; D020543:Proteome / Q000032:analysis*; D018085:Regulon; D041241:Vibrio cholerae O1 / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*
D001426:Bacterial Proteins; D010710:Phosphates; D020543:Proteome; C061278:PhoB protein, Bacteria