Phosphate Starvation-Inducible Proteins of Bacillus subtilis: Proteomics and Transcriptional Analysis
AUTOR(ES)
Antelmann, Haike
FONTE
American Society for Microbiology
RESUMO
The phosphate starvation response in Bacillus subtilis was analyzed using two-dimensional (2D) polyacrylamide gel electrophoresis of cell extracts and supernatants from phosphate-starved cells. Most of the phosphate starvation-induced proteins are under the control of ςB, the activity of which is increased by energy depletion. In order to define the proteins belonging to the Pho regulon, which is regulated by the two-component regulatory proteins PhoP and PhoR, the 2D protein pattern of the wild type was compared with those of a sigB mutant and a phoR mutant. By matrix-assisted laser desorption ionization–time of flight mass spectrometry, two alkaline phosphatases (APases) (PhoA and PhoB), an APase-alkaline phosphodiesterase (PhoD), a glycerophosphoryl diester phosphodiesterase (GlpQ), and the lipoprotein YdhF were identified as very strongly induced PhoPR-dependent proteins secreted into the extracellular medium. In the cytoplasmic fraction, PstB1, PstB2, and TuaD were identified as already known PhoPR-dependent proteins, in addition to PhoB, PhoD, and the previously described PstS. Transcriptional studies of glpQ and ydhF confirmed the strong PhoPR dependence. Northern hybridization and primer extension experiments showed that glpQ is transcribed monocistronically from a ςA promoter which is overlapped by four putative TT(A/T)ACA-like PhoP binding sites. Furthermore, ydhF might be cotranscribed with phoB initiating from the phoB promoter. Only a small group of proteins remained phosphate starvation inducible in both phoR and sigB mutant and did not form a unique regulation group. Among these, YfhM and YjbC were controlled by ςB-dependent and unknown PhoPR-independent mechanisms. Furthermore, YtxH and YvyD seemed to be induced after phosphate starvation in the wild type in a ςB-dependent manner and in the sigB mutant probably via ςH. YxiE was induced by phosphate starvation independently of ςB and PhoPR.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=94619Documentos Relacionados
- Bacillus subtilis PhoP binds to the phoB tandem promoter exclusively within the phosphate starvation-inducible promoter.
- Transcriptional regulation of Bacillus subtilis glucose starvation-inducible genes: control of gsiA by the ComP-ComA signal transduction system.
- Identification of phosphate starvation-inducible genes in Escherichia coli K-12 by DNA sequence analysis of psi::lacZ(Mu d1) transcriptional fusions.
- Characterization of the ccpA Gene of Enterococcus faecalis: Identification of Starvation-Inducible Proteins Regulated by CcpA
- Identification and characterization of a relA-dependent starvation-inducible locus (sin) in Salmonella typhimurium.