scholarly journals The pst operon of Bacillus subtilis has a phosphate-regulated promoter and is involved in phosphate transport but not in regulation of the pho regulon.

1997 ◽  
Vol 179 (8) ◽  
pp. 2534-2539 ◽  
Author(s):  
Y Qi ◽  
Y Kobayashi ◽  
F M Hulett
Keyword(s):  
Bacillus Subtilis ◽  
Phosphate Transport ◽  
Pho Regulon ◽  
Pst Operon

scholarly journals Autoinduction of Bacillus subtilis phoPR Operon Transcription Results from Enhanced Transcription from EσA- and EσE-Responsive Promoters by Phosphorylated PhoP

2004 ◽  
Vol 186 (13) ◽  
pp. 4262-4275 ◽  
Author(s):  
Salbi Paul ◽  
Stephanie Birkey ◽  
Wei Liu ◽  
F. Marion Hulett
Keyword(s):  
Bacillus Subtilis ◽  
Response Regulator ◽  
Phosphate Starvation ◽  
Growth Conditions ◽  
In Vitro Transcription ◽  
Phosphate Deficiency ◽  
Pho Regulon ◽  
Environmental Controls ◽  
Rna Polymerase Holoenzyme

ABSTRACT The phoPR operon encodes a response regulator, PhoP, and a histidine kinase, PhoR, which activate or repress genes of the Bacillus subtilis Pho regulon in response to an extracellular phosphate deficiency. Induction of phoPR upon phosphate starvation required activity of both PhoP and PhoR, suggesting autoregulation of the operon, a suggestion that is supported here by PhoP footprinting on the phoPR promoter. Primer extension analyses, using RNA from JH642 or isogenic sigE or sigB mutants isolated at different stages of growth and/or under different growth conditions, suggested that expression of the phoPR operon represents the sum of five promoters, each responding to a specific growth phase and environmental controls. The temporal expression of the phoPR promoters was investigated using in vitro transcription assays with RNA polymerase holoenzyme isolated at different stages of Pho induction, from JH642 or isogenic sigE or sigB mutants. In vitro transcription studies using reconstituted EσA, EσB, and EσE holoenzymes identified PA4 and PA3 as EσA promoters and PE2 as an EσE promoter. Phosphorylated PhoP (PhoP∼P) enhanced transcription from each of these promoters. EσB was sufficient for in vitro transcription of the PB1 promoter. P5 was active only in a sigB mutant strain. These studies are the first to report a role for PhoP∼P in activation of promoters that also have activity in the absence of Pho regulon induction and an activation role for PhoP∼P at an EσE promoter. Information concerning PB1 and P5 creates a basis for further exploration of the regulatory coordination or overlap of the PhoPR and SigB regulons during phosphate starvation.

scholarly journals Contribution of the pst-phoU Operon to Cell Adherence by Atypical Enteropathogenic Escherichia coli and Virulence of Citrobacter rodentium

2009 ◽  
Vol 77 (5) ◽  
pp. 1936-1944 ◽  
Author(s):  
Catherine Cheng ◽  
Sharon M. Tennant ◽  
Kristy I. Azzopardi ◽  
Vicki Bennett-Wood ◽  
Elizabeth L. Hartland ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacterial Colonization ◽  
Constitutive Expression ◽  
Site Directed Mutagenesis ◽  
Pho Regulon ◽  
Intestinal Epithelial ◽  
Citrobacter Rodentium ◽  
Atypical Epec ◽  
Pst Operon

ABSTRACT Strains of enteropathogenic Escherichia coli (EPEC) generally employ the adhesins bundle-forming pili (Bfp) and intimin to colonize the intestine. Atypical EPEC strains possess intimin but are negative for Bfp and, yet, are able to cause disease. To identify alternative adhesins to Bfp in atypical EPEC, we constructed a transposon mutant library of atypical EPEC strain E128012 (serotype O114:H2) using TnphoA. Six mutants that had lost the ability to adhere to HEp-2 cells were identified, and in all six mutants TnphoA had inserted into the pstSCAB-phoU (Pst) operon. To determine if the Pst operon is required for adherence, we used site-directed mutagenesis to construct a pstCA mutant of E128012. The resultant mutant showed a reduced ability to adhere to HEp-2 cells and T84 intestinal epithelial cells, which was restored by trans-complementation with intact pstCA. To determine if pst contributes to bacterial colonization in vivo, a pstCA mutation was made in the EPEC-like murine pathogen, Citrobacter rodentium. C57BL/6 mice infected perorally with the pstCA mutant of C. rodentium excreted significantly lower numbers of C. rodentium than those given the wild-type strain. Moreover, colonic hyperplasia and diarrhea, which are features of infections with C. rodentium, were not observed in mice infected with the pstCA mutant but did occur in mice given the trans-complemented mutant. As mutations in pst genes generally lead to constitutive expression of the Pho regulon, our findings suggested that the Pho regulon may contribute to the reduced virulence of the pstCA mutants. To investigate this, we inactivated phoB in the pstCA mutants of EPEC E128012 and C. rodentium and found that the phoB mutation restored the adherent phenotype of both mutant strains. These results demonstrate that Pst contributes to the virulence of atypical EPEC and C. rodentium, probably by causing increased expression of an unidentified, Pho-regulated adhesin.

scholarly journals Analysis of Bacillus subtilis tagAB andtagDEF Expression during Phosphate Starvation Identifies a Repressor Role for PhoP∼P

1998 ◽  
Vol 180 (3) ◽  
pp. 753-758 ◽  
Author(s):  
Wei Liu ◽  
Stephen Eder ◽  
F. Marion Hulett
Keyword(s):  
Cell Wall ◽  
Bacillus Subtilis ◽  
Teichoic Acid ◽  
Phosphate Starvation ◽  
Acid Synthesis ◽  
Pho Regulon ◽  
Wall Teichoic Acid ◽  
Negative Role ◽  
First Time ◽  
Starvation Conditions

ABSTRACT The tagAB and tagDEF operons, which are adjacent and divergently transcribed, encode genes responsible for cell wall teichoic acid synthesis in Bacillus subtilis. TheBacillus data presented here suggest that PhoP and PhoR are required for direct repression of transcription of the two operons under phosphate starvation conditions but have no regulatory role under phosphate-replete conditions. These data identify for the first time that PhoP∼P has a negative role in Pho regulon gene regulation.

scholarly journals Bacillus subtilis Phosphorylated PhoP: Direct Activation of the EσA- and Repression of the EσE-Responsive phoB-PS+V Promoters during Pho Response

2005 ◽  
Vol 187 (15) ◽  
pp. 5166-5178 ◽  
Author(s):  
Wael R. Abdel-Fattah ◽  
Yinghua Chen ◽  
Amr Eldakak ◽  
F. Marion Hulett
Keyword(s):  
Alkaline Phosphatase ◽  
Bacillus Subtilis ◽  
Type Strain ◽  
Wild Type Strain ◽  
Pho Regulon ◽  
Dependent Manner ◽  
Wild Type ◽  
Phosphate Deprivation

ABSTRACT The phoB gene of Bacillus subtilis encodes an alkaline phosphatase (PhoB, formerly alkaline phosphatase III) that is expressed from separate promoters during phosphate deprivation in a PhoP-PhoR-dependent manner and at stage two of sporulation under phosphate-sufficient conditions independent of PhoP-PhoR. Isogenic strains containing either the complete phoB promoter or individual phoB promoter fusions were used to assess expression from each promoter under both induction conditions. The phoB promoter responsible for expression during sporulation, phoB-PS, was expressed in a wild-type strain during phosphate deprivation, but induction occurred >3 h later than induction of Pho regulon genes and the levels were approximately 50-fold lower than that observed for the PhoPR-dependent promoter, phoB-PV. EσE was necessary and sufficient for PS expression in vitro. PS expression in a phoPR mutant strain was delayed 2 to 3 h compared to the expression in a wild-type strain, suggesting that expression or activation of σE is delayed in a phoPR mutant under phosphate-deficient conditions, an observation consistent with a role for PhoPR in spore development under these conditions. Phosphorylated PhoP (PhoP∼P) repressed PS in vitro via direct binding to the promoter, the first example of an EσE-responsive promoter that is repressed by PhoP∼P. Whereas either PhoP or PhoP∼P in the presence of EσA was sufficient to stimulate transcription from the phoB-PV promoter in vitro, roughly 10- and 17-fold-higher concentrations of PhoP than of PhoP∼P were required for PV promoter activation and maximal promoter activity, respectively. The promoter for a second gene in the Pho regulon, ykoL, was also activated by elevated concentrations of unphosphorylated PhoP in vitro. However, because no Pho regulon gene expression was observed in vivo during Pi -replete growth and PhoP concentrations increased only threefold in vivo during phoPR autoinduction, a role for unphosphorylated PhoP in Pho regulon activation in vivo is not likely.

scholarly journals Transcriptional Regulation of the phoPR Operon in Bacillus subtilis

2004 ◽  
Vol 186 (4) ◽  
pp. 1182-1190 ◽  
Author(s):  
Zoltán Prágai ◽  
Nicholas E. E. Allenby ◽  
Nicola O'Connor ◽  
Sarah Dubrac ◽  
Georges Rapoport ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Stationary Phase ◽  
Stress Responses ◽  
Response Regulator ◽  
Constitutive Expression ◽  
Phosphate Starvation ◽  
Pho Regulon ◽  
Dependent Manner ◽  
Low Level

ABSTRACT When Bacillus subtilis is subjected to phosphate starvation, the Pho regulon is activated by the PhoP-PhoR two-component signal transduction system to elicit specific responses to this nutrient limitation. The response regulator, PhoP, and its cognate histidine sensor kinase, PhoR, are encoded by the phoPR operon that is transcribed as a 2.7-kb bicistronic mRNA. The phoPR operon is transcribed from two σA-dependent promoters, P1 and P2. Under conditions where the Pho regulon was not induced (i.e., phosphate-replete conditions or phoR-null mutant), a low level of phoPR transcription was detected only from promoter P1. During phosphate starvation-induced transition from exponential to stationary phase, the expression of the phoPR operon was up-regulated in a phosphorylated PhoP (PhoP∼P)-dependent manner; in addition to P1, the P2 promoter becomes active. In vitro gel shift assays and DNase I footprinting experiments showed that both PhoP and PhoP∼P could bind to the control region of the phoPR operon. The data indicate that while low-level constitutive expression of phoPR is required under phosphate-replete conditions for signal perception and transduction, autoinduction is required to provide sufficient PhoP∼P to induce other members of the Pho regulon. The extent to which promoters P1 and P2 are activated appears to be influenced by the presence of other sigma factors, possibly the result of sigma factor competition. For example, phoPR is hyperinduced in a sigB mutant and, later in stationary phase, in sigH, sigF, and sigE mutants. The data point to a complex regulatory network in which other stress responses and post-exponential-phase processes influence the expression of phoPR and, thereby, the magnitude of the Pho regulon response.

Post-transcriptional regulation of the Bacillus subtilis pst operon encoding a phosphate-specific ABC transporter

Microbiology ◽  
2004 ◽  
Vol 150 (8) ◽  
pp. 2619-2628 ◽  
Author(s):  
Nicholas E. E. Allenby ◽  
Nicola O'Connor ◽  
Zoltán Prágai ◽  
Noel M. Carter ◽  
Marcus Miethke ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Reporter Gene ◽  
Messenger Rna ◽  
Northern Blotting ◽  
Gene Technology ◽  
Dna Arrays ◽  
Phosphate Binding ◽  
Pst Operon ◽  
Combination Of Methods ◽  
Post Transcriptional Regulation

During phosphate starvation, Bacillus subtilis regulates genes in the PhoP regulon to reduce the cell's requirement for this essential substrate and to facilitate the recovery of inorganic phosphate from organic sources such as teichoic and nucleic acids. Among the proteins that are highly induced under these conditions is PstS, the phosphate-binding lipoprotein component of a high-affinity ABC-type phosphate transporter. PstS is encoded by the first gene in the pst operon, the other four members of which encode the integral membrane and cytoplasmic components of the transporter. The transcription of the pst operon was analysed using a combination of methods, including transcriptional reporter gene technology, Northern blotting and DNA arrays. It is shown that the primary transcript of the pst operon is processed differentially to maintain higher concentrations of PstS relative to other components of the transporter. The comparative studies have revealed limitations in the use of reporter gene technology for analysing the transcription of operons in which the messenger RNA transcript is differentially processed.

scholarly journals Bacillus subtilis NhaC, an Na+/H+ Antiporter, Influences Expression of thephoPR Operon and Production of Alkaline Phosphatases

2001 ◽  
Vol 183 (8) ◽  
pp. 2505-2515 ◽  
Author(s):  
Zoltán Prágai ◽  
Caroline Eschevins ◽  
Sierd Bron ◽  
Colin R. Harwood
Keyword(s):  
Bacillus Subtilis ◽  
Target Gene ◽  
Transcriptional Unit ◽  
Secretory Proteins ◽  
Pho Regulon ◽  
Two Component System ◽  
Alkaline Phosphatases ◽  
Genes Encoding ◽  
Isogenic Mutants ◽  
Transcriptional Fusions

ABSTRACT When Bacillus subtilis is subjected to phosphate starvation, genes of the Pho regulon are either induced or repressed. Among those induced are genes encoding alkaline phosphatases (APases). A set of isogenic mutants, with a β-galactosidase gene transcriptionally fused to the inactivated target gene, was used to identify genes that influence the operation of the Pho regulon. One such gene was nhaC (previously yheL). In the absence of NhaC, growth and APase production were enhanced, while the production of other non-Pho-regulon secretory proteins (proteases and α-amylase) did not change. The influence of NhaC on growth, APase synthesis, and its own expression was dependent on the external Na+ concentration. Other monovalent cations such as Li+ or K+ had no effect. We propose a role for NhaC in the uptake of Na+. nhaC appears to be encoded by a monocistronic operon and, contrary to previous reports, is not in the same transcriptional unit as yheK, the gene immediately upstream. The increase in APase production was dependent on an active PhoR, the sensor kinase of the two-component system primarily responsible for controlling the Pho regulon. Transcriptional fusions showed that the phoPR operon and both phoA(encoding APaseA) and phoB (encoding APaseB) were hyperinduced in the absence of NhaC and repressed when this protein was overproduced. This suggests that NhaC effects APase production viaphoPR.

Sign in / Sign up

Export Citation Format

Share Document