scholarly journals Bacillus subtilis Tolerance of Moderate Concentrations of Rifampin Involves the σB-Dependent General and Multiple Stress Response

2002 ◽  
Vol 184 (2) ◽  
pp. 459-467 ◽  
Author(s):  
Julia Elisabeth Bandow ◽  
Heike Brötz ◽  
Michael Hecker
Keyword(s):  
Bacillus Subtilis ◽  
Stress Response ◽  
Rna Polymerase ◽  
Stress Proteins ◽  
Polyacrylamide Gel Electrophoresis ◽  
Growth Arrest ◽  
Wild Type ◽  
General Stress ◽  
Inhibition Of Growth ◽  
Increased Sensitivity

ABSTRACT Low concentrations of the RNA polymerase inhibitor rifampin added to an exponentially growing culture of Bacillus subtilis led to an instant inhibition of growth. Survival experiments revealed that during the growth arrest the cells became tolerant to the antibiotic and the culture was able to resume growth some time after rifampin treatment. l-[35S]methionine pulse-labeled protein extracts were separated by two-dimensional polyacrylamide gel electrophoresis to investigate the change in the protein synthesis pattern in response to rifampin. The σB-dependent general stress proteins were found to be induced after treatment with the antibiotic. Part of the oxidative stress signature was induced as indicated by the catalase KatA and MrgA. The target protein of rifampin, the β subunit (RpoB) of the DNA-dependent RNA polymerase, and the flagellin protein Hag belonging to the σD regulon were also induced. The rifampin-triggered growth arrest was extended in a sigB mutant in comparison to the wild-type strain, and the higher the concentration, the more pronounced this effect was. Activity of the RsbP energy-signaling phosphatase in the σB signal transduction network was also important for this protection against rifampin, but the RsbU environmental signaling phosphatase was not required. The sigB mutant strain was less capable of growing on rifampin-containing agar plates. When plated from a culture that had already reached stationary phase without previous exposure to the antibiotic during growth, the survival rate of the wild type exceeded that of the sigB mutant by a factor of 100. We conclude that the general stress response of B. subtilis is induced by rifampin depending on RsbP activity and that loss of SigB function causes increased sensitivity to the antibiotic.

scholarly journals Mechanisms of Adaptation to Nitrosative Stress in Bacillus subtilis

2007 ◽  
Vol 189 (8) ◽  
pp. 3063-3071 ◽  
Author(s):  
Annika Rogstam ◽  
Jonas T. Larsson ◽  
Peter Kjelgaard ◽  
Claes von Wachenfeldt
Keyword(s):  
Bacillus Subtilis ◽  
Stress Proteins ◽  
Nitrosative Stress ◽  
Vital Role ◽  
Null Mutant ◽  
Truncated Hemoglobin ◽  
Sigma B ◽  
Nitrosonium Cation ◽  
Mechanisms Of Adaptation ◽  
Increased Sensitivity

ABSTRACT Bacteria use a number of mechanisms for coping with the toxic effects exerted by nitric oxide (NO) and its derivatives. Here we show that the flavohemoglobin encoded by the hmp gene has a vital role in an adaptive response to protect the soil bacterium Bacillus subtilis from nitrosative stress. We further show that nitrosative stress induced by the nitrosonium cation donor sodium nitroprusside (SNP) leads to deactivation of the transcriptional repressor NsrR, resulting in derepression of hmp. Nitrosative stress induces the sigma B-controlled general stress regulon. However, a sigB null mutant did not show increased sensitivity to SNP, suggesting that the sigma B-dependent stress proteins are involved in a nonspecific protection against stress whereas the Hmp flavohemoglobin plays a central role in detoxification. Mutations in the yjbIH operon, which encodes a truncated hemoglobin (YjbI) and a predicted 34-kDa cytosolic protein of unknown function (YjbH), rendered B. subtilis hypersensitive to SNP, suggesting roles in nitrosative stress management.

scholarly journals Specific and general stress proteins in Bacillus subtilis - a two-dimensional protein electrophoresis study

Microbiology ◽  
1997 ◽  
Vol 143 (3) ◽  
pp. 999-1017 ◽  
Author(s):  
J. Bernhardt ◽  
U. Volker ◽  
A. Volker ◽  
H. Antelmann ◽  
R. Schmid ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Stress Proteins ◽  
Protein Electrophoresis ◽  
Two Dimensional ◽  
General Stress

scholarly journals Modeling the functioning of YtvA in the general stress response in Bacillus subtilis

2013 ◽  
Vol 9 (9) ◽  
pp. 2331 ◽  
Author(s):  
Jeroen B. van der Steen ◽  
Yusuke Nakasone ◽  
Johnny Hendriks ◽  
Klaas J. Hellingwerf
Keyword(s):  
Bacillus Subtilis ◽  
Stress Response ◽  
General Stress Response ◽  
General Stress

scholarly journals Comprehensive Characterization of the Contribution of Individual SigB-Dependent General Stress Genes to Stress Resistance of Bacillus subtilis

2005 ◽  
Vol 187 (8) ◽  
pp. 2810-2826 ◽  
Author(s):  
Dirk Höper ◽  
Uwe Völker ◽  
Michael Hecker
Keyword(s):  
Bacillus Subtilis ◽  
Heat Shock ◽  
Stress Resistance ◽  
Transcriptional Profiling ◽  
Stress Sensitivity ◽  
Phenotypic Screening ◽  
Common Component ◽  
Screening Analysis ◽  
General Stress ◽  
Increased Sensitivity

ABSTRACT Theσ B-dependent general stress regulon of Bacillus subtilis comprises more than 150 members. Induction of this regulon by imposition of environmental or metabolic stress confers multiple, nonspecific, and preemptive stress resistance to nongrowing, nonsporulated cells of B. subtilis. In this study we performed a regulon-wide phenotypic screening analysis to determine the stress sensitivity profiles of 94 mutants defective in candidate members of the general stress regulon that were previously identified in our transcriptional profiling study of the general stress response of B. subtilis. The phenotypic screening analysis included analysis of adaptation to a growth-inhibiting concentration of ethanol (10%, vol/vol) or NaCl (10%, wt/vol), severe heat shock (54°C), and low temperature (survival at 4°C and growth at 12.5°C). Surprisingly, 85% of the mutants tested displayed increased sensitivity at an α confidence level of ≤0.01 to at least one of the four stresses tested, and 62% still exhibited increased sensitivity at anα of ≤0.001. In essence, we were able to assign 63 genes (28 genes with an α of ≤0.001) to survival after ethanol shock, 37 genes (28 genes with an α of ≤0.001) to protection from NaCl shock, 34 genes (24 genes with an α of≤ 0.001) to survival at 4°C, and 10 genes (3 genes with an α of ≤0.001) to management of severe heat shock. Interestingly, there was a substantial overlap between the genes necessary for survival during ethanol shock and the genes necessary for survival at 4°C, and there was also an overlap between genes required for survival during ethanol shock and genes required for survival during NaCl shock. Our data provide evidence for the importance of the σB regulon at low temperatures, not only for growth but also for survival. Moreover, the data imply that a secondary oxidative stress seems to be a common component of the severe stresses tested.

scholarly journals Exposure of Bacillus subtilis to Low Pressure (5 Kilopascals) Induces Several Global Regulons, Including Those Involved in the SigB-Mediated General Stress Response

2014 ◽  
Vol 80 (16) ◽  
pp. 4788-4794 ◽  
Author(s):  
Samantha M. Waters ◽  
José A. Robles-Martínez ◽  
Wayne L. Nicholson
Keyword(s):  
Bacillus Subtilis ◽  
Stress Response ◽  
High Pressures ◽  
Low Pressure ◽  
Bacterial Cells ◽  
Content Type ◽  
General Stress Response ◽  
Cellular Processes ◽  
General Stress ◽  
Microbial Responses

ABSTRACTStudies of how microorganisms respond to pressure have been limited mostly to the extreme high pressures of the deep sea (i.e., the piezosphere). In contrast, despite the fact that the growth of most bacteria is inhibited at pressures below ∼2.5 kPa, little is known of microbial responses to low pressure (LP). To study the global LP response, we performed transcription microarrays onBacillus subtiliscells grown under normal atmospheric pressure (∼101 kPa) and a nearly inhibitory LP (5 kPa), equivalent to the pressure found at an altitude of ∼20 km. Microarray analysis revealed altered levels of 363 transcripts belonging to several global regulons (AbrB, CcpA, CodY, Fur, IolR, ResD, Rok, SigH, Spo0A). Notably, the highest number of upregulated genes, 86, belonged to the SigB-mediated general stress response (GSR) regulon. Upregulation of the GSR by LP was confirmed by monitoring the expression of the SigB-dependentctc-lacZreporter fusion. Measuring transcriptome changes resulting from exposure of bacterial cells to LP reveals insights into cellular processes that may respond to LP exposure.

scholarly journals Uncovering New Metabolic Capabilities of Bacillus subtilis Using Phenotype Profiling of Rifampin-Resistant rpoB Mutants

2007 ◽  
Vol 190 (3) ◽  
pp. 807-814 ◽  
Author(s):  
Amy E. Perkins ◽  
Wayne L. Nicholson
Keyword(s):  
Bacillus Subtilis ◽  
Rna Polymerase ◽  
Metabolic Profiling ◽  
Transcriptional Control ◽  
Β Subunit ◽  
Subunit Gene ◽  
Wild Type ◽  
Mutant Strains ◽  
Utilization Patterns ◽  
Flow Of Information

ABSTRACT RNA polymerase is a central macromolecular machine controlling the flow of information from genotype to phenotype, and insights into global transcriptional regulation can be gained by studying mutational perturbations in the enzyme. Mutations in the RNA polymerase β subunit gene rpoB causing resistance to rifampin (Rifr) in Bacillus subtilis were previously shown to lead to alterations in the expression of a number of global phenotypes known to be under transcriptional control, such as growth, competence for transformation, sporulation, and germination (H. Maughan, B. Galeano, and W. L. Nicholson, J. Bacteriol. 186:2481-2486, 2004). To better understand the global effects of rpoB mutations on metabolism, wild-type and 11 distinct congenic Rifr mutant strains of B. subtilis were tested for utilization of 95 substrates by use of Biolog GP2 MicroPlates. A number of alterations of substrate utilization patterns were observed in the Rifr mutants, including the utilization of novel substrates previously unknown in B. subtilis, such as gentiobiose, β-methyl-d-glucoside, and d-psicose. The results indicate that combining global metabolic profiling with mutations in RNA polymerase provides a system-wide approach for uncovering previously unknown metabolic capabilities and further understanding global transcriptional control circuitry in B. subtilis.

scholarly journals Calcium and S100B Regulation of p53-Dependent Cell Growth Arrest and Apoptosis

1998 ◽  
Vol 18 (7) ◽  
pp. 4272-4281 ◽  
Author(s):  
Christian Scotto ◽  
Jean Christophe Deloulme ◽  
Denis Rousseau ◽  
Edmond Chambaz ◽  
Jacques Baudier
Keyword(s):  
Cell Growth ◽  
Uv Irradiation ◽  
Growth Arrest ◽  
Nuclear Accumulation ◽  
Permissive Temperature ◽  
Wild Type ◽  
Cell Growth Arrest ◽  
Calcium Dependent ◽  
Inhibition Of Growth ◽  
Dependent Cell

ABSTRACT In glial C6 cells constitutively expressing wild-type p53, synthesis of the calcium-binding protein S100B is associated with cell density-dependent inhibition of growth and apoptosis in response to UV irradiation. A functional interaction between S100B and p53 was first demonstrated in p53-negative mouse embryo fibroblasts (MEF cells) by sequential transfection with the S100B and the temperature-sensitive p53Val135 genes. We show that in MEF cells expressing a low level of p53Val135, S100B cooperates with p53Val135 in triggering calcium-dependent cell growth arrest and cell death in response to UV irradiation at the nonpermissive temperature (37.5°C). Calcium-dependent growth arrest of MEF cells expressing S100B correlates with specific nuclear accumulation of the wild-type p53Val135 conformational species. S100B modulation of wild-type p53Val135 nuclear translocation and functions was confirmed with the rat embryo fibroblast (REF) cell line clone 6, which is transformed by oncogenic Ha-ras and overexpression of p53Val135. Ectopic expression of S100B in clone 6 cells restores contact inhibition of growth at 37.5°C, which also correlates with nuclear accumulation of the wild-type p53Val135 conformational species. Moreover, a calcium ionophore mediates a reversible G1 arrest in S100B-expressing REF (S100B-REF) cells at 37.5°C that is phenotypically indistinguishable from p53-mediated G1arrest at the permissive temperature (32°C). S100B-REF cells proceeding from G1 underwent apoptosis in response to UV irradiation. Our data support a model in which calcium signaling and S100B cooperate with the p53 pathways of cell growth inhibition and apoptosis.

scholarly journals The Blue-Light Receptor YtvA Acts in the Environmental Stress Signaling Pathway of Bacillus subtilis

2006 ◽  
Vol 188 (17) ◽  
pp. 6387-6395 ◽  
Author(s):  
Tatiana A. Gaidenko ◽  
Tae-Jong Kim ◽  
Andrea L. Weigel ◽  
Margaret S. Brody ◽  
Chester W. Price
Keyword(s):  
Bacillus Subtilis ◽  
Stress Response ◽  
Signaling Pathway ◽  
Blue Light ◽  
Stress Signaling ◽  
Negative Regulators ◽  
General Stress Response ◽  
Signaling Complex ◽  
General Stress ◽  
Stress Signaling Pathway

ABSTRACT The general stress response of the bacterium Bacillus subtilis is regulated by a partner-switching mechanism in which serine and threonine phosphorylation controls protein interactions in the stress-signaling pathway. The environmental branch of this pathway contains a family of five paralogous proteins that function as negative regulators. Here we present genetic evidence that a sixth paralog, YtvA, acts as a positive regulator in the same environmental signaling branch. We also present biochemical evidence that YtvA and at least three of the negative regulators can be isolated from cell extracts in a large environmental signaling complex. YtvA differs from these associated negative regulators by its flavin mononucleotide (FMN)-containing light-oxygen-voltage domain. Others have shown that this domain has the photochemistry expected for a blue-light sensor, with the covalent linkage of the FMN chromophore to cysteine 62 composing a critical part of the photocycle. Consistent with the view that light intensity modifies the output of the environmental signaling pathway, we found that cysteine 62 is required for YtvA to exert its positive regulatory role in the absence of other stress. Transcriptional analysis of the ytvA structural gene indicated that it provides the entry point for at least one additional environmental input, mediated by the Spx global regulator of disulfide stress. These results support a model in which the large signaling complex serves to integrate multiple environmental signals in order to modulate the general stress response.

scholarly journals PhyR Is Involved in the General Stress Response of Methylobacterium extorquens AM1

2007 ◽  
Vol 190 (3) ◽  
pp. 1027-1035 ◽  
Author(s):  
Benjamin Gourion ◽  
Anne Francez-Charlot ◽  
Julia A. Vorholt
Keyword(s):  
Stress Response ◽  
Heat Shock ◽  
Stress Responses ◽  
Target Genes ◽  
Stress Proteins ◽  
Plant Colonization ◽  
Methylobacterium Extorquens ◽  
General Stress Response ◽  
Amino Terminal ◽  
General Stress

ABSTRACTPhyR represents a novel alphaproteobacterial family of response regulators having a structure consisting of two domains; a predicted amino-terminal extracytoplasmic function (ECF) sigma factor-like domain and a carboxy-terminal receiver domain. PhyR was first described inMethylobacterium extorquensAM1, in which it has been shown to be essential for plant colonization, probably due to its suggested involvement in the regulation of a number of stress proteins. Here we investigated the PhyR regulon using microarray technology. We found that the PhyR regulon is rather large and that most of the 246 targets are under positive control. Mapping of transcriptional start sites revealed candidate promoters for PhyR-mediated regulation. One of these promoters, an ECF-type promoter, was identified upstream of one-third of the target genes by in silico analysis. Among the PhyR targets are genes predicted to be involved in multiple stress responses, includingkatE,osmC,htrA,dnaK,gloA,dps, anduvrA. The induction of these genes is consistent with our phenotypic analyses which revealed that PhyR is involved in resistance to heat shock and desiccation, as well as oxidative, UV, ethanol, and osmotic stresses, inM. extorquensAM1. The finding that PhyR is involved in the general stress response was further substantiated by the finding that carbon starvation induces protection against heat shock and that this protection is at least in part dependent on PhyR.

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