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Yeak KYC, Tempelaars M, Wu JL, Westerveld W, Reder A, Michalik S, Dhople VM, Völker U, Pané-Farré J, Wells-Bennik MHJ, Abee T. SigB modulates expression of novel SigB regulon members via Bc1009 in non-stressed and heat-stressed cells revealing its alternative roles in Bacillus cereus. BMC Microbiol 2023; 23:37. [PMID: 36759782 PMCID: PMC9912610 DOI: 10.1186/s12866-023-02783-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 01/24/2023] [Indexed: 02/11/2023] Open
Abstract
BACKGROUND The Bacillus cereus Sigma B (SigB) dependent general stress response is activated via the two-component RsbKY system, which involves a phosphate transfer from RsbK to RsbY. It has been hypothesized that the Hpr-like phosphocarrier protein (Bc1009) encoded by bc1009 in the SigB gene cluster may play a role in this transfer, thereby acting as a regulator of SigB activation. Alternatively, Bc1009 may be involved in the activation of a subset of SigB regulon members. RESULTS We first investigated the potential role of bc1009 to act as a SigB regulator but ruled out this possibility as the deletion of bc1009 did not affect the expression of sigB and other SigB gene cluster members. The SigB-dependent functions of Bc1009 were further examined in B. cereus ATCC14579 via comparative proteome profiling (backed up by transcriptomics) of wt, Δbc1009 and ΔsigB deletion mutants under heat stress at 42 °C. This revealed 284 proteins displaying SigB-dependent alterations in protein expression levels in heat-stressed cells, including a subgroup of 138 proteins for which alterations were also Bc1009-dependent. Next to proteins with roles in stress defense, newly identified SigB and Bc1009-dependent proteins have roles in cell motility, signal transduction, transcription, cell wall biogenesis, and amino acid transport and metabolism. Analysis of lethal stress survival at 50 °C after pre-adaptation at 42 °C showed intermediate survival efficacy of Δbc1009 cells, highest survival of wt, and lowest survival of ΔsigB cells, respectively. Additional comparative proteome analysis of non-stressed wt and mutant cells at 30 °C revealed 96 proteins with SigB and Bc1009-dependent differences in levels: 51 were also identified under heat stress, and 45 showed significant differential expression at 30 °C. This includes proteins with roles in carbohydrate/ion transport and metabolism. Overlapping functions at 30 °C and 42 °C included proteins involved in motility, and ΔsigB and Δbc1009 cells showed reduced motility compared to wt cells in swimming assays at both temperatures. CONCLUSION Our results extend the B. cereus SigB regulon to > 300 members, with a novel role of SigB-dependent Bc1009 in the activation of a subregulon of > 180 members, conceivably via interactions with other transcriptional regulatory networks.
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Affiliation(s)
- Kah Yen Claire Yeak
- grid.419921.60000 0004 0588 7915NIZO, Kernhemseweg 2, PO Box 20, 6718 ZB Ede, The Netherlands ,grid.4818.50000 0001 0791 5666Food Microbiology, Wageningen University and Research, PO Box 8129, 6700 EV Wageningen, The Netherlands
| | - Marcel Tempelaars
- grid.4818.50000 0001 0791 5666Food Microbiology, Wageningen University and Research, PO Box 8129, 6700 EV Wageningen, The Netherlands
| | - Jia Lun Wu
- grid.4818.50000 0001 0791 5666Food Microbiology, Wageningen University and Research, PO Box 8129, 6700 EV Wageningen, The Netherlands
| | - Wouter Westerveld
- grid.4818.50000 0001 0791 5666Food Microbiology, Wageningen University and Research, PO Box 8129, 6700 EV Wageningen, The Netherlands
| | - Alexander Reder
- grid.5603.0Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Stephan Michalik
- grid.5603.0Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Vishnu M. Dhople
- grid.5603.0Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Uwe Völker
- grid.5603.0Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, Greifswald, Germany
| | - Jan Pané-Farré
- grid.10253.350000 0004 1936 9756Center for Synthetic Microbiology (SYNMIKRO) & Department of Chemistry, Philipps-University Marburg, Karl-Von-Frisch-Strasse 14, 35043 Marburg, Germany
| | | | - Tjakko Abee
- Food Microbiology, Wageningen University and Research, PO Box 8129, 6700 EV, Wageningen, The Netherlands.
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Guerreiro DN, Pucciarelli MG, Tiensuu T, Gudynaite D, Boyd A, Johansson J, García-del Portillo F, O’Byrne CP. Acid stress signals are integrated into the σB-dependent general stress response pathway via the stressosome in the food-borne pathogen Listeria monocytogenes. PLoS Pathog 2022; 18:e1010213. [PMID: 35275969 PMCID: PMC8942246 DOI: 10.1371/journal.ppat.1010213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 03/23/2022] [Accepted: 02/28/2022] [Indexed: 12/17/2022] Open
Abstract
The general stress response (GSR) in Listeria monocytogenes plays a critical role in the survival of this pathogen in the host gastrointestinal tract. The GSR is regulated by the alternative sigma factor B (σB), whose role in protection against acid stress is well established. Here, we investigated the involvement of the stressosome, a sensory hub, in transducing low pH signals to induce the GSR. Mild acid shock (15 min at pH 5.0) activated σB and conferred protection against a subsequent lethal pH challenge. A mutant strain where the stressosome subunit RsbR1 was solely present retained the ability to induce σB activity at pH 5.0. The role of stressosome phosphorylation in signal transduction was investigated by mutating the putative phosphorylation sites in the core stressosome proteins RsbR1 (rsbR1-T175A, -T209A, -T241A) and RsbS (rsbS-S56A), or the stressosome kinase RsbT (rsbT-N49A). The rsbS S56A and rsbT N49A mutations abolished the response to low pH. The rsbR1-T209A and rsbR1-T241A mutants displayed constitutive σB activity. Mild acid shock upregulates invasion genes inlAB and stimulates epithelial cell invasion, effects that were abolished in mutants with an inactive or overactive stressosome. Overall, the results show that the stressosome is required for acid-induced activation of σB in L. monocytogenes. Furthermore, they show that RsbR1 can function independently of its paralogues and signal transduction requires RsbT-mediated phosphorylation of RsbS on S56 and RsbR1 on T209 but not T175. These insights shed light on the mechanisms of signal transduction that activate the GSR in L. monocytogenes in response to acidic environments, and highlight the role this sensory process in the early stages of the infectious cycle. The stress sensing hub known as the stressosome, found in many bacterial and archaeal lineages, plays a crucial role in both stress tolerance and virulence in the food-borne pathogen Listeria monocytogenes. However, the mechanisms that lead to its activation and the subsequent activation of the general stress response have remained elusive. In this study, we examined the signal transduction mechanisms that operate in the stressosome in response to acid stress. We found that only one of the five putative sensory proteins present in L. monocytogenes, RsbR1, was required for effective transduction of acid tress signals. We further found that phosphorylation of RsbS and RsbR1, mediated by the RsbT kinase, is essential for signal transduction. Failure to phosphorylate RsbS on Serine 56 completely abolished acid sensing by the stressosome, which prevented the development of adaptive acid tolerance. The acid-induced activation of internalin gene expression was also abolished in mutants with defective stressosome signalling, suggesting a role for the stressosome in the invasion of host cells. Together the data provide new insights into the mechanisms that activate the stressosome in response to acid stress and highlight the role this sensory hub plays in virulence.
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Affiliation(s)
- Duarte N. Guerreiro
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, National University of Ireland, Galway, Ireland
| | - M. Graciela Pucciarelli
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid, Centre of Molecular Biology ‘Severo Ochoa’ (CBMSO CSIC-UAM), Madrid, Spain
| | - Teresa Tiensuu
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre of Microbial Research, Umeå, Sweden
| | - Diana Gudynaite
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, National University of Ireland, Galway, Ireland
| | - Aoife Boyd
- Pathogenic Mechanisms Research Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Jörgen Johansson
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Centre of Microbial Research, Umeå, Sweden
| | | | - Conor P. O’Byrne
- Bacterial Stress Response Group, Microbiology, School of Biological and Chemical Sciences, National University of Ireland, Galway, Ireland
- * E-mail:
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3
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Genetic Factors Affect the Survival and Behaviors of Selected Bacteria during Antimicrobial Blue Light Treatment. Int J Mol Sci 2021; 22:ijms221910452. [PMID: 34638788 PMCID: PMC8508746 DOI: 10.3390/ijms221910452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/26/2022] Open
Abstract
Antimicrobial resistance is a global, mounting and dynamic issue that poses an immediate threat to human, animal, and environmental health. Among the alternative antimicrobial treatments proposed to reduce the external use of antibiotics is electromagnetic radiation, such as blue light. The prevailing mechanistic model is that blue light can be absorbed by endogenous porphyrins within the bacterial cell, inducing the production of reactive oxygen species, which subsequently inflict oxidative damages upon different cellular components. Nevertheless, it is unclear whether other mechanisms are involved, particularly those that can affect the efficacy of antimicrobial blue light treatments. In this review, we summarize evidence of inherent factors that may confer protection to a selected group of bacteria against blue light-induced oxidative damages or modulate the physiological characteristics of the treated bacteria, such as virulence and motility. These include descriptions of three major photoreceptors in bacteria, chemoreceptors, SOS-dependent DNA repair and non-SOS protective mechanisms. Future directions are also provided to assist with research efforts to increase the efficacy of antimicrobial blue light and to minimize the development of blue light-tolerant phenotypes.
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4
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Dessaux C, Guerreiro DN, Pucciarelli MG, O'Byrne CP, García-Del Portillo F. Impact of osmotic stress on the phosphorylation and subcellular location of Listeria monocytogenes stressosome proteins. Sci Rep 2020; 10:20837. [PMID: 33257749 PMCID: PMC7705745 DOI: 10.1038/s41598-020-77738-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 11/17/2020] [Indexed: 12/14/2022] Open
Abstract
Listeria monocytogenes responds to environmental stress using a supra-macromolecular complex, the stressosome, to activate the stress sigma factor SigB. The stressosome structure, inferred from in vitro-assembled complexes, consists of the core proteins RsbR (here renamed RsbR1) and RsbS and, the kinase RsbT. The active complex is proposed to be tethered to the membrane and to support RsbR1/RsbS phosphorylation by RsbT and the subsequent release of RsbT following signal perception. Here, we show in actively-growing cells that L. monocytogenes RsbR1 and RsbS localize mostly in the cytosol in a fully phosphorylated state regardless of osmotic stress. RsbT however distributes between cytosolic and membrane-associated pools. The kinase activity of RsbT on RsbR1/RsbS and its requirement for maximal SigB activation in response to osmotic stress were demonstrated in vivo. Cytosolic RsbR1 interacts with RsbT, while this interaction diminishes at the membrane when RsbR1 paralogues (RsbR2, RsbR3 and RsbL) are present. Altogether, the data support a model in which phosphorylated RsbR1/RsbS may sustain basal SigB activity in unstressed cells, probably assuring a rapid increase in such activity in response to stress. Our findings also suggest that in vivo the active RsbR1-RsbS-RsbT complex forms only transiently and that membrane-associated RsbR1 paralogues could modulate its assembly.
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Affiliation(s)
- Charlotte Dessaux
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Darwin 3, 28049, Madrid, Spain
| | - Duarte N Guerreiro
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, H91 TK33, Ireland
| | - M Graciela Pucciarelli
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Darwin 3, 28049, Madrid, Spain.,Department of Molecular Biology, Centre of Molecular Biology 'Severo Ochoa' (CBMSO)-CSIC, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Conor P O'Byrne
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, H91 TK33, Ireland
| | - Francisco García-Del Portillo
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB)-CSIC, Darwin 3, 28049, Madrid, Spain.
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5
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Bonilla CY. Generally Stressed Out Bacteria: Environmental Stress Response Mechanisms in Gram-Positive Bacteria. Integr Comp Biol 2020; 60:126-133. [PMID: 32044998 DOI: 10.1093/icb/icaa002] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The ability to monitor the environment for toxic chemical and physical disturbances is essential for bacteria that live in dynamic environments. The fundamental sensing mechanisms and physiological responses that allow bacteria to thrive are conserved even if the molecular components of these pathways are not. The bacterial general stress response (GSR) represents a conceptual model for how one pathway integrates a wide range of environmental signals, and how a generalized system with broad molecular responses is coordinated to promote survival likely through complementary pathways. Environmental stress signals such as heat, osmotic stress, and pH changes are received by sensor proteins that through a signaling cascade activate the sigma factor, SigB, to regulate over 200 genes. Additionally, the GSR plays an important role in stress priming that increases bacterial fitness to unrelated subsequent stressors such as oxidative compounds. While the GSR response is implicated during oxidative stress, the reason for its activation remains unknown and suggests crosstalk between environmental and oxidative stress sensors and responses to coordinate antioxidant functions. Systems levels studies of cellular responses such as transcriptomes, proteomes, and metabolomes of stressed bacteria and single-cell analysis could shed light into the regulated functions that protect, remediate, and minimize damage during dynamic environments. This perspective will focus on fundamental stress sensing mechanisms and responses in Gram-positive bacterial species to illustrate their commonalities at the molecular and physiological levels; summarize exciting directions; and highlight how system-level approaches can help us understand bacterial physiology.
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Affiliation(s)
- Carla Y Bonilla
- Biology Department, Gonzaga University, 502 East Boone Avenue, Spokane, WA 99258, USA
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6
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Guerreiro DN, Arcari T, O'Byrne CP. The σ B-Mediated General Stress Response of Listeria monocytogenes: Life and Death Decision Making in a Pathogen. Front Microbiol 2020; 11:1505. [PMID: 32733414 PMCID: PMC7358398 DOI: 10.3389/fmicb.2020.01505] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 06/10/2020] [Indexed: 12/17/2022] Open
Abstract
Sensing and responding to environmental cues is critical for the adaptability and success of the food-borne bacterial pathogen Listeria monocytogenes. A supramolecular multi-protein complex known as the stressosome, which acts as a stress sensing hub, is responsible for orchestrating the activation of a signal transduction pathway resulting in the activation of σB, the sigma factor that controls the general stress response (GSR). When σB is released from the anti-sigma factor RsbW, a rapid up-regulation of the large σB regulon, comprised of ≥ 300 genes, ensures that cells respond appropriately to the new environmental conditions. A diversity of stresses including low pH, high osmolarity, and blue light are known to be sensed by the stressosome, resulting in a generalized increase in stress resistance. Appropriate activation of the stressosome and deployment of σB are critical to fitness as there is a trade-off between growth and stress protection when the GSR is deployed. We review the recent developments in this field and describe an up-to-date model of how this sensory organelle might integrate environmental signals to produce an appropriate activation of the GSR. Some of the outstanding questions and challenges in this fascinating field are also discussed.
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Affiliation(s)
- Duarte N Guerreiro
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Talia Arcari
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Conor P O'Byrne
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
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7
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Guerreiro DN, Wu J, Dessaux C, Oliveira AH, Tiensuu T, Gudynaite D, Marinho CM, Boyd A, García-Del Portillo F, Johansson J, O'Byrne CP. Mild Stress Conditions during Laboratory Culture Promote the Proliferation of Mutations That Negatively Affect Sigma B Activity in Listeria monocytogenes. J Bacteriol 2020; 202:e00751-19. [PMID: 32094160 PMCID: PMC7148139 DOI: 10.1128/jb.00751-19] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/01/2020] [Indexed: 12/18/2022] Open
Abstract
In Listeria monocytogenes, the full details of how stress signals are integrated into the σB regulatory pathway are not yet available. To help shed light on this question, we investigated a collection of transposon mutants that were predicted to have compromised activity of the alternative sigma factor B (σB). These mutants were tested for acid tolerance, a trait that is known to be under σB regulation, and they were found to display increased acid sensitivity, similar to a mutant lacking σB (ΔsigB). The transposon insertions were confirmed by whole-genome sequencing, but in each case, the strains were also found to carry a frameshift mutation in the sigB operon. The changes were predicted to result in premature stop codons, with negative consequences for σB activation, independently of the transposon location. Reduced σB activation in these mutants was confirmed. Growth measurements under conditions similar to those used during the construction of the transposon library revealed that the frameshifted sigB operon alleles conferred a growth advantage at higher temperatures, during late exponential phase. Mixed-culture experiments at 42°C demonstrated that the loss of σB activity allowed mutants to take over a population of parental bacteria. Together, our results suggest that mutations affecting σB activity can arise during laboratory culture because of the growth advantage conferred by these mutations under mild stress conditions. The data highlight the significant cost of stress protection in this foodborne pathogen and emphasize the need for whole-genome sequence analysis of newly constructed strains to confirm the expected genotype.IMPORTANCE In the present study, we investigated a collection of Listeria monocytogenes strains that all carried sigB operon mutations. The mutants all had reduced σB activity and were found to have a growth advantage under conditions of mild heat stress (42°C). In mixed cultures, these mutants outcompeted the wild type when mild heat stress was present but not at an optimal growth temperature. An analysis of 22,340 published L. monocytogenes genome sequences found a high rate of premature stop codons present in genes positively regulating σB activity. Together, these findings suggest that the occurrence of mutations that attenuate σB activity can be favored under conditions of mild stress, probably highlighting the burden on cellular resources that stems from deploying the general stress response.
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Affiliation(s)
- Duarte N Guerreiro
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Jialun Wu
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
| | - Charlotte Dessaux
- Laboratory of Intracellular Bacterial Pathogens, National Center for Biotechnology (CNB)-CSIC, Madrid, Spain
| | - Ana H Oliveira
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Center of Microbial Research, Umeå, Sweden
| | - Teresa Tiensuu
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Center of Microbial Research, Umeå, Sweden
| | - Diana Gudynaite
- Molecular Microbiology Department, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Catarina M Marinho
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
- Université Bourgogne Franche-Conté, Dijon, France
- Institut National de la Recherche Agronomique, UMR Agroécologie, Dijon, France
| | - Aoife Boyd
- Pathogenic Mechanisms Research Group, National University of Ireland, Galway, Ireland
| | | | - Jörgen Johansson
- Laboratory for Molecular Infection Medicine Sweden, Department of Molecular Biology, Umeå Center of Microbial Research, Umeå, Sweden
| | - Conor P O'Byrne
- Bacterial Stress Response Group, Microbiology, School of Natural Sciences, National University of Ireland, Galway, Ireland
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Kwon E, Pathak D, Kim HU, Dahal P, Ha SC, Lee SS, Jeong H, Jeoung D, Chang HW, Jung HS, Kim DY. Structural insights into stressosome assembly. IUCRJ 2019; 6:938-947. [PMID: 31576226 PMCID: PMC6760441 DOI: 10.1107/s205225251900945x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 07/02/2019] [Indexed: 05/05/2023]
Abstract
The stressosome transduces environmental stress signals to SigB to upregulate SigB-dependent transcription, which is required for bacterial viability. The stressosome core is composed of RsbS and at least one of the RsbR paralogs. A previous cryo-electron microscopy (cryo-EM) structure of the RsbRA-RsbS complex determined under a D2 symmetry restraint showed that the stressosome core forms a pseudo-icosahedron consisting of 60 STAS domains of RsbRA and RsbS. However, it is still unclear how RsbS and one of the RsbR paralogs assemble into the stressosome. Here, an assembly model of the stressosome is presented based on the crystal structure of the RsbS icosahedron and cryo-EM structures of the RsbRA-RsbS complex determined under diverse symmetry restraints (nonsymmetric C1, dihedral D2 and icosahedral I envelopes). 60 monomers of the crystal structure of RsbS fitted well into the I-restrained cryo-EM structure determined at 4.1 Å resolution, even though the STAS domains in the I envelope were averaged. This indicates that RsbS and RsbRA share a highly conserved STAS fold. 22 protrusions observed in the C1 envelope, corresponding to dimers of the RsbRA N-domain, allowed the STAS domains of RsbRA and RsbS to be distinguished in the stressosome core. Based on these, the model of the stressosome core was reconstructed. The mutation of RsbRA residues at the binding interface in the model (R189A/Q191A) significantly reduced the interaction between RsbRA and RsbS. These results suggest that nonconserved residues in the conserved STAS folds between RsbS and RsbR paralogs determine stressosome assembly.
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Affiliation(s)
- Eunju Kwon
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Deepak Pathak
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Han-ul Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Pawan Dahal
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Sung Chul Ha
- Pohang Accelerator Laboratory (PAL), Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Seung Sik Lee
- Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 56212, Republic of Korea
- Department of Radiation Science and Technology, University of Science and Technology, Daejeon 34113, Republic of Korea
| | - Hyeongseop Jeong
- Center for Electron Microscopy Research, Korea Basic Science Institute, Ochang 28119, Republic of Korea
| | - Dooil Jeoung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Hyeun Wook Chang
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, Gangwon 24341, Republic of Korea
| | - Dong Young Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
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Williams AH, Redzej A, Rolhion N, Costa TRD, Rifflet A, Waksman G, Cossart P. The cryo-electron microscopy supramolecular structure of the bacterial stressosome unveils its mechanism of activation. Nat Commun 2019; 10:3005. [PMID: 31285450 PMCID: PMC6614362 DOI: 10.1038/s41467-019-10782-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 05/22/2019] [Indexed: 01/18/2023] Open
Abstract
How the stressosome, the epicenter of the stress response in bacteria, transmits stress signals from the environment has remained elusive. The stressosome consists of multiple copies of three proteins RsbR, RsbS and RsbT, a kinase that is important for its activation. Using cryo-electron microscopy, we determined the atomic organization of the Listeria monocytogenes stressosome at 3.38 Å resolution. RsbR and RsbS are organized in a 60-protomers truncated icosahedron. A key phosphorylation site on RsbR (T209) is partially hidden by an RsbR flexible loop, whose "open" or "closed" position could modulate stressosome activity. Interaction between three glutamic acids in the N-terminal domain of RsbR and the membrane-bound mini-protein Prli42 is essential for Listeria survival to stress. Together, our data provide the atomic model of the stressosome core and highlight a loop important for stressosome activation, paving the way towards elucidating the mechanism of signal transduction by the stressosome in bacteria.
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Affiliation(s)
- Allison H Williams
- Unité Biologie et Génétique de la Paroi Bactérienne, Institut Pasteur, Groupe Avenir, INSERM, 75015, Paris, France.
| | - Adam Redzej
- Institute of Structural and Molecular Biology, University College London and Birkbeck, London, WC1E 7HX, UK
| | - Nathalie Rolhion
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, 75015, Paris, France.,Inserm, U604, 75015, Paris, France.,INRA, Unité sous-contrat 2020, 75015, Paris, France
| | - Tiago R D Costa
- Institute of Structural and Molecular Biology, University College London and Birkbeck, London, WC1E 7HX, UK.,MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, UK
| | - Aline Rifflet
- Unité Biologie et Génétique de la Paroi Bactérienne, Institut Pasteur, Groupe Avenir, INSERM, 75015, Paris, France
| | - Gabriel Waksman
- Institute of Structural and Molecular Biology, University College London and Birkbeck, London, WC1E 7HX, UK.
| | - Pascale Cossart
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, 75015, Paris, France. .,Inserm, U604, 75015, Paris, France. .,INRA, Unité sous-contrat 2020, 75015, Paris, France.
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10
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Johansson J, Freitag NE. Regulation of Listeria monocytogenes Virulence. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0064-2019. [PMID: 31441398 PMCID: PMC10957223 DOI: 10.1128/microbiolspec.gpp3-0064-2019] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Indexed: 02/07/2023] Open
Abstract
Whereas obligate human and animal bacterial pathogens may be able to depend upon the warmth and relative stability of their chosen replication niche, environmental bacteria such as Listeria monocytogenes that harbor the ability to replicate both within animal cells and in the outside environment must maintain the capability to manage life under a variety of disparate conditions. Bacterial life in the outside environment requires adaptation to wide ranges of temperature, available nutrients, and physical stresses such as changes in pH and osmolarity as well as desiccation. Following ingestion by a susceptible animal host, the bacterium must adapt to similar changes during transit through the gastrointestinal tract and overcome a variety of barriers associated with host innate immune responses. Rapid alteration of patterns of gene expression and protein synthesis represent one strategy for quickly adapting to a dynamic host landscape. Here, we provide an overview of the impressive variety of strategies employed by the soil-dwelling, foodborne, mammalian pathogen L. monocytogenes to straddle diverse environments and optimize bacterial fitness both inside and outside host cells.
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Affiliation(s)
- Jörgen Johansson
- Department of Molecular Biology, Laboratory for Molecular Infection Medicine Sweden (MIMS) and Umeå Centre for Microbial Research (UCMR), Umeå University, 90187 Umeå, Sweden
| | - Nancy E Freitag
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago IL
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11
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Role and regulation of the stress activated sigma factor sigma B (σ B) in the saprophytic and host-associated life stages of Listeria monocytogenes. ADVANCES IN APPLIED MICROBIOLOGY 2019; 106:1-48. [PMID: 30798801 DOI: 10.1016/bs.aambs.2018.11.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The stress activated sigma factor sigma B (σB) plays a pivotal role in allowing the food-borne bacterial pathogen Listeria monocytogenes to modulate its transcriptional landscape in order to survive in a variety of harsh environments both outside and within the host. While we have a comparatively good understanding of the systems under the control of this sigma factor much less is known about how the activity of σB is controlled. In this review, we present a current model describing how this sigma factor is thought to be controlled including an overview of what is known about stress sensing and the early signal transduction events that trigger its activation. We discuss the known regulatory overlaps between σB and other protein and RNA regulators in the cell. Finally, we describe the role of σB in surviving both saprophytic and host-associated stresses. The complexity of the regulation of this sigma factor reflects the significant role that it plays in the persistence of this important pathogen in the natural environment, the food chain as well as within the host during the early stages of an infection. Understanding its regulation will be a critical step in helping to develop rational strategies to prevent its growth and survival in the food destined for human consumption and in the prevention of listeriosis.
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12
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Bouillet S, Arabet D, Jourlin-Castelli C, Méjean V, Iobbi-Nivol C. Regulation of σ factors by conserved partner switches controlled by divergent signalling systems. ENVIRONMENTAL MICROBIOLOGY REPORTS 2018; 10:127-139. [PMID: 29393573 DOI: 10.1111/1758-2229.12620] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 01/18/2018] [Accepted: 01/19/2018] [Indexed: 06/07/2023]
Abstract
Partner-Switching Systems (PSS) are widespread regulatory systems, each comprising a kinase-anti-σ, a phosphorylatable anti-σ antagonist and a phosphatase module. The anti-σ domain quickly sequesters or delivers the target σ factor according to the phosphorylation state of the anti-σ antagonist induced by environmental signals. The PSS components are proteins alone or merged to other domains probably to adapt to the input signals. PSS are involved in major cellular processes including stress response, sporulation, biofilm formation and pathogenesis. Surprisingly, the target σ factors are often unknown and the sensing modules acting upstream from the PSS diverge according to the bacterial species. Indeed, they belong to either two-component systems or complex pathways as the stressosome or Chemosensory Systems (CS). Based on a phylogenetic analysis, we propose that the sensing module in Gram-negative bacteria is often a CS.
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Affiliation(s)
- Sophie Bouillet
- Aix-Marseille University, CNRS, BIP UMR7281, 13402 Marseille, France
| | - Dallel Arabet
- Université des Frères Mentouri Constantine 1, Constantine, Algeria
| | | | - Vincent Méjean
- Aix-Marseille University, CNRS, BIP UMR7281, 13402 Marseille, France
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13
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Comparative genomics sheds light on niche differentiation and the evolutionary history of comammox Nitrospira. ISME JOURNAL 2018. [PMID: 29515170 DOI: 10.1038/s41396-018-0083-3] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The description of comammox Nitrospira spp., performing complete ammonia-to-nitrate oxidation, and their co-occurrence with canonical β-proteobacterial ammonia oxidizing bacteria (β-AOB) in the environment, calls into question the metabolic potential of comammox Nitrospira and the evolutionary history of their ammonia oxidation pathway. We report four new comammox Nitrospira genomes, constituting two novel species, and the first comparative genomic analysis on comammox Nitrospira. Unlike canonical Nitrospira, comammox Nitrospira genomes lack genes for assimilatory nitrite reduction, suggesting that they have lost the potential to use external nitrite nitrogen sources. By contrast, compared to canonical Nitrospira, comammox Nitrospira harbor a higher diversity of urea transporters and copper homeostasis genes and lack cyanate hydratase genes. Additionally, the two comammox clades differ in their ammonium uptake systems. Contrary to β-AOB, comammox Nitrospira genomes have single copies of the two central ammonia oxidation pathway operons. Similar to ammonia oxidizing archaea and some oligotrophic AOB strains, they lack genes involved in nitric oxide reduction. Furthermore, comammox Nitrospira genomes encode genes that might allow efficient growth at low oxygen concentrations. Regarding the evolutionary history of comammox Nitrospira, our analyses indicate that several genes belonging to the ammonia oxidation pathway could have been laterally transferred from β-AOB to comammox Nitrospira. We postulate that the absence of comammox genes in other sublineage II Nitrospira genomes is the result of subsequent loss.
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14
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Abstract
The discovery of the globin-coupled sensor (GCS) family of haem proteins has provided new insights into signalling proteins and pathways by which organisms sense and respond to changing oxygen levels. GCS proteins consist of a sensor globin domain linked to a variety of output domains, suggesting roles in controlling numerous cellular pathways, and behaviours in response to changing oxygen concentration. Members of this family of proteins have been identified in the genomes of numerous organisms and characterization of GCS with output domains, including methyl accepting chemotaxis proteins, kinases, and diguanylate cyclases, have yielded an understanding of the mechanism by which oxygen controls activity of GCS protein output domains, as well as downstream proteins and pathways regulated by GCS signalling. Future studies will expand our understanding of these proteins both in vitro and in vivo, likely demonstrating broad roles for GCS in controlling oxygen-dependent microbial physiology and phenotypes.
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15
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Impens F, Rolhion N, Radoshevich L, Bécavin C, Duval M, Mellin J, García Del Portillo F, Pucciarelli MG, Williams AH, Cossart P. N-terminomics identifies Prli42 as a membrane miniprotein conserved in Firmicutes and critical for stressosome activation in Listeria monocytogenes. Nat Microbiol 2017; 2:17005. [PMID: 28191904 DOI: 10.1038/nmicrobiol.2017.5] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/04/2017] [Indexed: 12/25/2022]
Abstract
To adapt to changing environments, bacteria have evolved numerous pathways that activate stress response genes. In Gram-positive bacteria, the stressosome, a cytoplasmic complex, relays external cues and activates the sigma B regulon. The stressosome is structurally well-characterized in Bacillus, but how it senses stress remains elusive. Here, we report a genome-wide N-terminomic approach in Listeria that strikingly led to the discovery of 19 internal translation initiation sites and 6 miniproteins, among which one, Prli42, is conserved in Firmicutes. Prli42 is membrane-anchored and interacts with orthologues of Bacillus stressosome components. We reconstituted the Listeria stressosome in vitro and visualized its supramolecular structure by electron microscopy. Analysis of a series of Prli42 mutants demonstrated that Prli42 is important for sigma B activation, bacterial growth following oxidative stress and for survival in macrophages. Taken together, our N-terminonic approach unveiled Prli42 as a long-sought link between stress and the stressosome.
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Affiliation(s)
- Francis Impens
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
| | - Nathalie Rolhion
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
| | - Lilliana Radoshevich
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
| | - Christophe Bécavin
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France.,Institut Pasteur, Bioinformatics and Biostatistics Hub, C3BI, USR 3756 IP CNRS, Paris, France
| | - Mélodie Duval
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
| | - Jeffrey Mellin
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
| | | | - M Graciela Pucciarelli
- Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), Madrid, Spain.,Departamento de Biología Molecular, Universidad Autónoma de Madrid, Centro de Biología Molecular 'Severo Ochoa' (CBMSO-CSIC), Madrid, Spain
| | - Allison H Williams
- Département de Microbiologie, Institut Pasteur, Unité des Biologie et génétique de la paroi bactérienne, F-75015 Paris, France.,INSERM, Groupe Avenir, F-75015 Paris, France
| | - Pascale Cossart
- Département de Biologie Cellulaire et Infection, Institut Pasteur, Unité des Interactions Bactéries-Cellules, F-75015 Paris, France.,Inserm, U604, F-75015 Paris, France.,INRA, Unité sous-contrat 2020, F-75015 Paris, France
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16
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Lebreton A, Stavru F, Brisse S, Cossart P. 1926-2016: 90 Years of listeriology. Microbes Infect 2016; 18:711-723. [PMID: 27876526 DOI: 10.1016/j.micinf.2016.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 10/26/2016] [Indexed: 01/28/2023]
Abstract
ISOPOL - for "International Symposium on Problems of Listeria and Listeriosis" - meetings gather every three years since 1957 participants from all over the world and allow exchange and update on a wide array of topics concerning Listeria and listeriosis, ranging from epidemiology, diagnostic and typing methods, to genomics, post-genomics, fundamental microbiology, cell biology and pathogenesis. The XIXth ISOPOL meeting took place in Paris from June 14th to 17th, 2016 at Institut Pasteur. We provide here a report of the talks that were given during the meeting, which represents an up-to-date overview of ongoing research on this important pathogen and biological model.
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Affiliation(s)
- Alice Lebreton
- École normale supérieure, PSL Research University, CNRS, Inserm, Institut de Biologie de l'École Normale Supérieure (IBENS), Équipe Infection et Devenir de l'ARN, 75005 Paris, France; INRA, IBENS, 75005 Paris, France
| | - Fabrizia Stavru
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, 75015 Paris, France; Inserm, U604, 75015 Paris, France; INRA, USC2020, 75015 Paris, France; CNRS, SNC5101, Paris, France
| | - Sylvain Brisse
- Institut Pasteur, Molecular Prevention and Therapy of Human Diseases, 75724 Paris, France; Institut Pasteur, Microbial Evolutionary Genomics, 75724 Paris, France; CNRS, UMR 3525, Paris, France
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, 75015 Paris, France; Inserm, U604, 75015 Paris, France; INRA, USC2020, 75015 Paris, France.
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17
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Nagler K, Krawczyk AO, De Jong A, Madela K, Hoffmann T, Laue M, Kuipers OP, Bremer E, Moeller R. Identification of Differentially Expressed Genes during Bacillus subtilis Spore Outgrowth in High-Salinity Environments Using RNA Sequencing. Front Microbiol 2016; 7:1564. [PMID: 27766092 PMCID: PMC5052260 DOI: 10.3389/fmicb.2016.01564] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 09/20/2016] [Indexed: 12/02/2022] Open
Abstract
In its natural habitat, the soil bacterium Bacillus subtilis often has to cope with fluctuating osmolality and nutrient availability. Upon nutrient depletion it can form dormant spores, which can revive to form vegetative cells when nutrients become available again. While the effects of salt stress on spore germination have been analyzed previously, detailed knowledge on the salt stress response during the subsequent outgrowth phase is lacking. In this study, we investigated the changes in gene expression during B. subtilis outgrowth in the presence of 1.2 M NaCl using RNA sequencing. In total, 402 different genes were upregulated and 632 genes were downregulated during 90 min of outgrowth in the presence of salt. The salt stress response of outgrowing spores largely resembled the osmospecific response of vegetative cells exposed to sustained high salinity and included strong upregulation of genes involved in osmoprotectant uptake and compatible solute synthesis. The σB-dependent general stress response typically triggered by salt shocks was not induced, whereas the σW regulon appears to play an important role for osmoadaptation of outgrowing spores. Furthermore, high salinity induced many changes in the membrane protein and transporter transcriptome. Overall, salt stress seemed to slow down the complex molecular reorganization processes (“ripening”) of outgrowing spores by exerting detrimental effects on vegetative functions such as amino acid metabolism.
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Affiliation(s)
- Katja Nagler
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center Cologne, Germany
| | - Antonina O Krawczyk
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Anne De Jong
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Kazimierz Madela
- Advanced Light and Electron Microscopy, Center for Biological Threats and Special Pathogens, Robert Koch Institute Berlin, Germany
| | - Tamara Hoffmann
- Laboratory of Microbiology, Department of Biology, Philipps-University Marburg Marburg, Germany
| | - Michael Laue
- Advanced Light and Electron Microscopy, Center for Biological Threats and Special Pathogens, Robert Koch Institute Berlin, Germany
| | - Oscar P Kuipers
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen Groningen, Netherlands
| | - Erhard Bremer
- Laboratory of Microbiology, Department of Biology, Philipps-University Marburg Marburg, Germany
| | - Ralf Moeller
- Space Microbiology Research Group, Radiation Biology Department, Institute of Aerospace Medicine, German Aerospace Center Cologne, Germany
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18
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An O2-sensing stressosome from a Gram-negative bacterium. Nat Commun 2016; 7:12381. [PMID: 27488264 PMCID: PMC4976288 DOI: 10.1038/ncomms12381] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 06/28/2016] [Indexed: 12/16/2022] Open
Abstract
Bacteria have evolved numerous pathways to sense and respond to changing environmental conditions, including, within Gram-positive bacteria, the stressosome complex that regulates transcription of general stress response genes. However, the signalling molecules recognized by Gram-positive stressosomes have yet to be identified, hindering our understanding of the signal transduction mechanism within the complex. Furthermore, an analogous pathway has yet to be described in Gram-negative bacteria. Here we characterize a putative stressosome from the Gram-negative bacterium Vibrio brasiliensis. The sensor protein RsbR binds haem and exhibits ligand-dependent control of the stressosome complex activity. Oxygen binding to the haem decreases activity, while ferrous RsbR results in increased activity, suggesting that the V. brasiliensis stressosome may be activated when the bacterium enters anaerobic growth conditions. The findings provide a model system for investigating ligand-dependent signalling within stressosome complexes, as well as insights into potential pathways controlled by oxygen-dependent signalling within Vibrio species.
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19
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Resilience in the Face of Uncertainty: Sigma Factor B Fine-Tunes Gene Expression To Support Homeostasis in Gram-Positive Bacteria. Appl Environ Microbiol 2016; 82:4456-4469. [PMID: 27208112 DOI: 10.1128/aem.00714-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Gram-positive bacteria are ubiquitous and diverse microorganisms that can survive and sometimes even thrive in continuously changing environments. The key to such resilience is the ability of members of a population to respond and adjust to dynamic conditions in the environment. In bacteria, such responses and adjustments are mediated, at least in part, through appropriate changes in the bacterial transcriptome in response to the conditions encountered. Resilience is important for bacterial survival in diverse, complex, and rapidly changing environments and requires coordinated networks that integrate individual, mechanistic responses to environmental cues to enable overall metabolic homeostasis. In many Gram-positive bacteria, a key transcriptional regulator of the response to changing environmental conditions is the alternative sigma factor σ(B) σ(B) has been characterized in a subset of Gram-positive bacteria, including the genera Bacillus, Listeria, and Staphylococcus Recent insight from next-generation-sequencing results indicates that σ(B)-dependent regulation of gene expression contributes to resilience, i.e., the coordination of complex networks responsive to environmental changes. This review explores contributions of σ(B) to resilience in Bacillus, Listeria, and Staphylococcus and illustrates recently described regulatory functions of σ(B).
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20
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van der Steen JB, Hellingwerf KJ. Activation of the General Stress Response of Bacillus subtilis by Visible Light. Photochem Photobiol 2015; 91:1032-45. [PMID: 26189730 DOI: 10.1111/php.12499] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Accepted: 06/25/2015] [Indexed: 12/20/2022]
Abstract
A key challenge for microbiology is to understand how evolution has shaped the wiring of regulatory networks. This is amplified by the paucity of information of power-spectra of physicochemical stimuli to which microorganisms are exposed. Future studies of genome evolution, driven by altered stimulus regimes, will therefore require a versatile signal transduction system that allows accurate signal dosing. Here, we review the general stress response of Bacillus subtilis, and its upstream signal transduction network, as a candidate system. It can be activated by red and blue light, and by many additional stimuli. Signal integration therefore is an intricate function of this system. The blue-light response is elicited via the photoreceptor YtvA, which forms an integral part of stressosomes, to activate expression of the stress regulon of B. subtilis. Signal transfer through this network can be assayed with reporter enzymes, while intermediate steps can be studied with live-cell imaging of fluorescently tagged proteins. Different parts of this system have been studied in vitro, such that its computational modeling has made significant progress. One can directly relate the microscopic characteristics of YtvA with activation of the general stress regulon, making this system a very well-suited system for network evolution studies.
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Affiliation(s)
- Jeroen B van der Steen
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Klaas J Hellingwerf
- Molecular Microbial Physiology Group, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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21
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Abstract
Microorganisms live in fluctuating environments, requiring stress response pathways to resist environmental insults and stress. These pathways dynamically monitor cellular status, and mediate adaptive changes by remodeling the proteome, largely accomplished by remodeling transcriptional networks and protein degradation. The complementarity of fast, specific proteolytic degradation and slower, broad transcriptomic changes gives cells the mechanistic repertoire to dynamically adjust cellular processes and optimize response behavior. Together, this enables cells to minimize the 'cost' of the response while maximizing the ability to survive environmental stress. Here we highlight recent progress in our understanding of transcriptional networks and proteolysis that illustrates the design principles used by bacteria to generate the complex behaviors required to resist stress.
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22
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Koch G, Yepes A, Förstner KU, Wermser C, Stengel ST, Modamio J, Ohlsen K, Foster KR, Lopez D. Evolution of resistance to a last-resort antibiotic in Staphylococcus aureus via bacterial competition. Cell 2014; 158:1060-1071. [PMID: 25171407 PMCID: PMC4163622 DOI: 10.1016/j.cell.2014.06.046] [Citation(s) in RCA: 135] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Revised: 04/28/2014] [Accepted: 06/23/2014] [Indexed: 01/02/2023]
Abstract
Antibiotic resistance is a key medical concern, with antibiotic use likely being an important cause. However, here we describe an alternative route to clinically relevant antibiotic resistance that occurs solely due to competitive interactions among bacterial cells. We consistently observe that isolates of Methicillin-resistant Staphylococcus aureus diversify spontaneously into two distinct, sequentially arising strains. The first evolved strain outgrows the parent strain via secretion of surfactants and a toxic bacteriocin. The second is resistant to the bacteriocin. Importantly, this second strain is also resistant to intermediate levels of vancomycin. This so-called VISA (vancomycin-intermediate S. aureus) phenotype is seen in many hard-to-treat clinical isolates. This strain diversification also occurs during in vivo infection in a mouse model, which is consistent with the fact that both coevolved phenotypes resemble strains commonly found in clinic. Our study shows how competition between coevolving bacterial strains can generate antibiotic resistance and recapitulate key clinical phenotypes.
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Affiliation(s)
- Gudrun Koch
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Ana Yepes
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Konrad U Förstner
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Charlotte Wermser
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Stephanie T Stengel
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Jennifer Modamio
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany
| | - Knut Ohlsen
- Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany
| | - Kevin R Foster
- Department of Zoology, University of Oxford, Oxford OX1 3QU, UK; Oxford Centre for Integrative Systems Biology, University of Oxford, Oxford OX1 3QU, UK
| | - Daniel Lopez
- Research Centre for Infectious Diseases (ZINF), University of Würzburg, Würzburg 97080, Germany; Institute for Molecular Infection Biology (IMIB), University of Würzburg, Würzburg 97080, Germany.
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23
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Sharma AK, Rigby AC, Alper SL. STAS domain structure and function. Cell Physiol Biochem 2011; 28:407-22. [PMID: 22116355 PMCID: PMC3709189 DOI: 10.1159/000335104] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2011] [Indexed: 12/23/2022] Open
Abstract
Pendrin shares with nearly all SLC26/SulP anion transporters a carboxy-terminal cytoplasmic segment organized around a Sulfate Transporter and Anti-Sigma factor antagonist (STAS) domain. STAS domains of divergent amino acid sequence exhibit a conserved fold of 4 β strands interspersed among 5 α helices. The first STAS domain proteins studied were single-domain anti-sigma factor antagonists (anti-anti-σ). These anti-anti-σ indirectly stimulate bacterial RNA polymerase by inactivating inhibitory anti-σ kinases, liberating σ factors to direct specific transcription of target genes or operons. Some STAS domains are nucleotide-binding phosphoproteins or nucleotidases. Others are interaction/transduction modules within multidomain sensors of light, oxygen and other gasotransmitters, cyclic nucleotides, inositol phosphates, and G proteins. Additional multidomain STAS protein sequences suggest functions in sensing, metabolism, or transport of nutrients such as sugars, amino acids, lipids, anions, vitamins, or hydrocarbons. Still other multidomain STAS polypeptides include histidine and serine/threonine kinase domains and ligand-activated transcription factor domains. SulP/SLC26 STAS domains and adjacent sequences interact with other transporters, cytoskeletal scaffolds, and with enzymes metabolizing transported anion substrates, forming putative metabolons. STAS domains are central to membrane targeting of many SulP/SLC26 anion transporters, and STAS domain mutations are associated with at least three human recessive diseases. This review summarizes STAS domain structure and function.
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Affiliation(s)
- Alok K Sharma
- Molecular and Vascular Medicine Division, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, MA 02215, USA.
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24
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Non-transcriptional regulatory processes shape transcriptional network dynamics. Nat Rev Microbiol 2011; 9:817-28. [PMID: 21986901 DOI: 10.1038/nrmicro2667] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Information about the extra- or intracellular environment is often captured as biochemical signals that propagate through regulatory networks. These signals eventually drive phenotypic changes, typically by altering gene expression programmes in the cell. Reconstruction of transcriptional regulatory networks has given a compelling picture of bacterial physiology, but transcriptional network maps alone often fail to describe phenotypes. Cellular response dynamics are ultimately determined by interactions between transcriptional and non-transcriptional networks, with dramatic implications for physiology and evolution. Here, we provide an overview of non-transcriptional interactions that can affect the performance of natural and synthetic bacterial regulatory networks.
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25
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Abstract
Bacteria construct elaborate nanostructures, obtain nutrients and energy from diverse sources, synthesize complex molecules, and implement signal processing to react to their environment. These complex phenotypes require the coordinated action of multiple genes, which are often encoded in a contiguous region of the genome, referred to as a gene cluster. Gene clusters sometimes contain all of the genes necessary and sufficient for a particular function. As an evolutionary mechanism, gene clusters facilitate the horizontal transfer of the complete function between species. Here, we review recent work on a number of clusters whose functions are relevant to biotechnology. Engineering these clusters has been hindered by their regulatory complexity, the need to balance the expression of many genes, and a lack of tools to design and manipulate DNA at this scale. Advances in synthetic biology will enable the large-scale bottom-up engineering of the clusters to optimize their functions, wake up cryptic clusters, or to transfer them between organisms. Understanding and manipulating gene clusters will move towards an era of genome engineering, where multiple functions can be "mixed-and-matched" to create a designer organism.
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Affiliation(s)
- Michael Fischbach
- Department of Bioengineering and Therapeutic Sciences, University of California – San Francisco, MC 2530, Room 308C, 1700 4 Street, (415) 514-9435
| | - Christopher A. Voigt
- Department of Pharmaceutical Chemistry, University of California – San Francisco, MC 2540, Room 408C, 1700 4 Street, San Francisco, CA 94158, (415) 502-7050
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