Regulatory interactions between the Pho and σB-dependent general stress regulons of Bacillus subtilis

Prágai, Zoltán; Harwood, Colin R.

doi:10.1099/00221287-148-5-1593

Cited by 87 publications

(88 citation statements)

References 38 publications

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“…Their downregulation has been linked to various stress experiences (Ishige et al, 2003;Lawrence et al, 2004;Silberbach et al, 2005;Silberbach and Burkovski, 2006) and a decrease of cellular growth (Stintzi, 2003). Genes Cf_3502 and Cf_2039, in clusters P and Q, respectively, encode two Csb proteins (Akbar et al, 1999;Prágai and Harwood, 2002). These are activated during the general stress response, which is triggered by energy or environmental stress and aims at protecting DNA, proteins and membranes from damage (Hecker and Volker, 1998).…”

Section: General Stress Response and Ribosomal Proteinsmentioning

confidence: 99%

Dual transcriptional profiling of a bacterial/fungal confrontation: Collimonas fungivorans versus Aspergillus niger

et al. 2011

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Interactions between bacteria and fungi cover a wide range of incentives, mechanisms and outcomes. The genus Collimonas consists of soil bacteria that are known for their antifungal activity and ability to grow at the expense of living fungi. In non-contact confrontation assays with the fungus Aspergillus niger, Collimonas fungivorans showed accumulation of biomass concomitant with inhibition of hyphal spread. Through microarray analysis of bacterial and fungal mRNA from the confrontation arena, we gained new insights into the mechanisms underlying the fungistatic effect and mycophagous phenotype of collimonads. Collimonas responded to the fungus by activating genes for the utilization of fungal-derived compounds and for production of a putative antifungal compound. In A. niger, differentially expressed genes included those involved in lipid and cell wall metabolism and cell defense, which correlated well with the hyphal deformations that were observed microscopically. Transcriptional profiles revealed distress in both partners: downregulation of ribosomal proteins and upregulation of mobile genetic elements in the bacteria and expression of endoplasmic reticulum stress and conidia-related genes in the fungus. Both partners experienced nitrogen shortage in each other's presence. Overall, our results indicate that the Collimonas/ Aspergillus interaction is a complex interplay between trophism, antibiosis and competition for nutrients.

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Section: General Stress Response and Ribosomal Proteinsmentioning

confidence: 99%

Dual transcriptional profiling of a bacterial/fungal confrontation: Collimonas fungivorans versus Aspergillus niger

et al. 2011

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“…[25][26][27] The ctc gene, described as being positively regulated by s B in L. monocytogenes, 11 was also used in a transcriptomic approach to investigate blue and red light activation of s B in L. monocytogenes. 28 The study demonstrated that in a DsigB mutant there was still substantial ctc transcript levels, suggesting that in L. monocytogenes ctc transcription is not fully dependent on s B .…”

Section: Introductionmentioning

confidence: 99%

Development and optimization of an EGFP-based reporter for measuring the general stress response inListeria monocytogenes

et al. 2012

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A characteristic of the food-borne pathogen Listeria monocytogenes is its tolerance to the harsh conditions found both in minimally processed foods and the human gastrointestinal tract. This trait is partly under the control of the alternative sigma factor sigma B (s B ). To study the mechanisms that trigger the activation of s B , and hence the development of stress tolerance, we have developed a fluorescent reporter fusion that allows the real-time activity of s B to be monitored. The reporter, designated P lmo2230 ::egfp, fuses the strong s B -dependent promoter from the lmo2230 gene (which encodes a putative arsenate reductase) to a gene encoding enhanced green fluorescence protein (EGFP). The reporter was integrated into the genomes of the wild-type strain L. monocytogenes EGD-e as well as two mutant derivatives lacking either sigB or rsbV. The resulting strains were used to study s B activation in response to growth phase and hyperosmotic stress. The wild-type was strongly fluorescent in stationary phase or in cultures with added NaCl and this fluorescence was abolished in both the sigB and rsbV backgrounds, consistent with the s B -dependency of the lmo2230 promoter. During sudden osmotic upshock (addition of 0.5 M NaCl during growth) a real-time increase in fluorescence was observed microscopically, reaching maximal activation after 30 min. Flow cytometry was used to study the activation of s B at a population level by hyperosmotic stress during exponential growth. A strong and proportional increase in fluorescence was observed as the salt concentration increased from 0 to 0.9 M NaCl. Interestingly, there was considerable heterogeneity within the population and a significant proportion of cells failed to induce a high level of fluorescence, suggesting that s B activation occurs stochastically in response to hyperosmotic stress. Thus the P lmo2230 ::egfp is a powerful tool that will allow the stress response to be better studied in this important human pathogen.

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“…Concomitant repression of the teichoic acid operons (tagAB and tagDEF) and induction of teichuronic acid operon (tuaA to tuaH) conserves phosphate by bringing about the controlled replacement of the phosphate-containing cell wall polymer teichoic acid with the non-phosphate-containing teichuronic acid (21,24,28). The functions of five putative Pho regulon genes (ydhF, ykoL, yhaX, yhbH, and yttP) are presently unknown (2,32,36).…”

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confidence: 99%

Transcriptional Regulation of thephoPROperon inBacillus subtilis

et al. 2004

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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 A -dependent promoters, P 1 and P 2 . 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 P 1 . During phosphate starvation-induced transition from exponential to stationary phase, the expression of the phoPR operon was up-regulated in a phosphorylated PhoP (PhoPϳP)-dependent manner; in addition to P 1 , the P 2 promoter becomes active. In vitro gel shift assays and DNase I footprinting experiments showed that both PhoP and PhoPϳP 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 PhoPϳP to induce other members of the Pho regulon. The extent to which promoters P 1 and P 2 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.

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Regulatory interactions between the Pho and σB-dependent general stress regulons of Bacillus subtilis

Cited by 87 publications

References 38 publications

Dual transcriptional profiling of a bacterial/fungal confrontation: Collimonas fungivorans versus Aspergillus niger

Dual transcriptional profiling of a bacterial/fungal confrontation: Collimonas fungivorans versus Aspergillus niger

Development and optimization of an EGFP-based reporter for measuring the general stress response inListeria monocytogenes

Transcriptional Regulation of thephoPROperon inBacillus subtilis

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