1
|
Engling P, Héchard T, Edgren T, Francis M, Dersch P, Wang H. Calcium-responsive plasmid copy number regulation is dependent on discrete YopD domains in Yersinia pseudotuberculosis. Plasmid 2023; 126:102683. [PMID: 37075853 DOI: 10.1016/j.plasmid.2023.102683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/30/2023] [Accepted: 04/15/2023] [Indexed: 04/21/2023]
Abstract
Yersinia pathogenicity depends mainly on a Type III Secretion System (T3SS) responsible for translocating effector proteins into the eukaryotic target cell cytosol. The T3SS is encoded on a 70 kb, low copy number virulence plasmid, pYV. A key T3SS regulator, YopD, is a multifunctional protein and consists of discrete modular domains that are essential for pore formation and translocation of Yop effectors. In Y. pseudotuberculosis, the temperature-dependent plasmid copy number increase that is essential for elevated T3SS gene dosage and virulence is also affected by YopD. Here, we found that the presence of intracellular YopD results in increased levels of the CopA-RNA and CopB, two inhibitors of plasmid replication. Secretion of YopD leads to decreased expression of copA and copB, resulting in increased plasmid copy number. Moreover, using a systematic mutagenesis of YopD mutants, we demonstrated that the same discrete modular domains important for YopD translocation are also necessary for both the regulation of plasmid copy number as well as copA and copB expression. Hence, Yersinia has evolved a mechanism coupling active secretion of a plasmid-encoded component of the T3SS, YopD, to the regulation of plasmid replication. Our work provides evidence for the cross-talk between plasmid-encoded functions with the IncFII replicon.
Collapse
Affiliation(s)
- Pit Engling
- Department of Molecular Infection Biology, Helmholtz Center for Infection Research
| | - Tifaine Héchard
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Tomas Edgren
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Matthew Francis
- Department of Molecular Biology and Umeå Center for Microbial Research, Umeå University, Umeå, Sweden
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Center for Infection Research; Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), University of Münster, Münster, Germany.
| | - Helen Wang
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden.
| |
Collapse
|
2
|
Fei K, Chao HJ, Hu Y, Francis MS, Chen S. CpxR regulates the Rcs phosphorelay system in controlling the Ysc-Yop type III secretion system in Yersinia pseudotuberculosis. MICROBIOLOGY-SGM 2021; 167. [PMID: 33295859 DOI: 10.1099/mic.0.000998] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The CpxRA two-component regulatory system and the Rcs phosphorelay system are both employed by the Enterobacteriaceae family to preserve bacterial envelope integrity and function when growing under stress. Although both systems regulate several overlapping physiological processes, evidence demonstrating a molecular connection between Cpx and Rcs signalling outputs is scarce. Here, we show that CpxR negatively regulates the transcription of the rcsB gene in the Rcs phosphorelay system in Yersinia pseudotuberculosis. Interestingly, transcription of rcsB is under the control of three promoters, which were all repressed by CpxR. Critically, synthetic activation of Cpx signalling through mislocalization of the NlpE lipoprotein to the inner membrane resulted in an active form of CpxR that repressed activity of rcsB promoters. On the other hand, a site-directed mutation of the phosphorylation site at residue 51 in CpxR generated an inactive non-phosphorylated variant that was unable to regulate output from these rcsB promoters. Importantly, CpxR-mediated inhibition of rcsB transcription in turn restricted activation of the Ysc-Yop type III secretion system (T3SS). Moreover, active CpxR blocks zinc-mediated activation of Rcs signalling and the subsequent activation of lcrF transcription. Our results demonstrate a novel regulatory cascade linking CpxR-RcsB-LcrF to control production of the Ysc-Yop T3SS.
Collapse
Affiliation(s)
- Keke Fei
- University of Chinese Academy of Sciences, Beijing, PR China.,Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, PR China
| | - Hong-Jun Chao
- Present address: School of Biological & pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan, PR China.,Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, PR China
| | - Yangbo Hu
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, PR China
| | - Matthew S Francis
- Department of Molecular Biology, Umeå University, Umeå, Sweden; Umeå Centre for Microbial Research, Umeå University, Umeå, Sweden
| | - Shiyun Chen
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan, PR China
| |
Collapse
|
3
|
Böhme K, Heroven AK, Lobedann S, Guo Y, Stolle AS, Dersch P. The Small Protein YmoA Controls the Csr System and Adjusts Expression of Virulence-Relevant Traits of Yersinia pseudotuberculosis. Front Microbiol 2021; 12:706934. [PMID: 34413840 PMCID: PMC8369931 DOI: 10.3389/fmicb.2021.706934] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Accepted: 07/12/2021] [Indexed: 11/24/2022] Open
Abstract
Virulence gene expression of Yersinia pseudotuberculosis changes during the different stages of infection and this is tightly controlled by environmental cues. In this study, we show that the small protein YmoA, a member of the Hha family, is part of this process. It controls temperature- and nutrient-dependent early and later stage virulence genes in an opposing manner and co-regulates bacterial stress responses and metabolic functions. Our analysis further revealed that YmoA exerts this function by modulating the global post-transcriptional regulatory Csr system. YmoA pre-dominantly enhances the stability of the regulatory RNA CsrC. This involves a stabilizing stem-loop structure within the 5′-region of CsrC. YmoA-mediated CsrC stabilization depends on H-NS, but not on the RNA chaperone Hfq. YmoA-promoted reprogramming of the Csr system has severe consequences for the cell: we found that a mutant deficient of ymoA is strongly reduced in its ability to enter host cells and to disseminate to the Peyer’s patches, mesenteric lymph nodes, liver and spleen in mice. We propose a model in which YmoA controls transition from the initial colonization phase in the intestine toward the host defense phase important for the long-term establishment of the infection in underlying tissues.
Collapse
Affiliation(s)
- Katja Böhme
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Stephanie Lobedann
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Yuzhu Guo
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), Medical Faculty Münster, University of Münster, Münster, Germany
| | - Anne-Sophie Stolle
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), Medical Faculty Münster, University of Münster, Münster, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), Medical Faculty Münster, University of Münster, Münster, Germany
| |
Collapse
|
4
|
Lon Protease- and Temperature-Dependent Activity of a Lysis Cassette Located in the Insecticidal Island of Yersinia enterocolitica. J Bacteriol 2021; 203:JB.00616-20. [PMID: 33288626 DOI: 10.1128/jb.00616-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 11/30/2020] [Indexed: 11/20/2022] Open
Abstract
The Yersinia genus comprises pathogens that can adapt to an environmental life cycle stage as well as to mammals. Yersinia enterocolitica strain W22703 exhibits both insecticidal and nematocidal activity conferred by the tripartite toxin complex (Tc) that is encoded on the 19-kb pathogenicity island Tc-PAI Ye All tc genes follow a strict temperature regulation in that they are silenced at 37°C but activated at lower temperatures. Four highly conserved phage-related genes, located within the Tc-PAI Ye , were recently demonstrated to encode a biologically functional holin-endolysin gene cassette that lyses its own host W22703 at 37°C. Conditions transcriptionally activating the cassette are not yet known. In contrast to Escherichia coli, the overproduction of holin and endolysin did not result in cell lysis of strain W22703 at 15°C. When the holin-endolysin genes were overexpressed at 15°C in four Y. enterocolitica biovars and in four other Yersinia spp., a heterogenous pattern of phenotypes was observed, ranging from lysis resistance of a biovar 1A strain to the complete growth arrest of a Y. kristensenii strain. To decipher the molecular mechanism underlying this temperature-dependent lysis, we constructed a Lon protease-negative mutant of W22703 in which the overexpression of the lysis cassette leads to cell death at 15°C. Overexpressed endolysin exhibited a high proteolytic susceptibility in strain W22703 but remained stable in the W22703 Δlon strain or in Y. pseudotuberculosis Although artificial overexpression was applied here, the data indicate that Lon protease plays a role in the control of the temperature-dependent lysis in Y. enterocolitica W22703.IMPORTANCE The investigation of the mechanisms that help pathogens survive in the environment is a prerequisite to understanding their evolution and their virulence capacities. In members of the genus Yersinia, many factors involved in virulence, metabolism, motility, or biofilm formation follow a strict temperature-dependent regulation. While the molecular mechanisms underlying the activation of determinants at body temperature have been analyzed in detail, the molecular basis of low-temperature-dependent phenotypes is largely unknown. Here, we demonstrate that a novel phage-related lysis cassette, which is part of the insecticidal and nematocidal pathogenicity island of Y. enterocolitica, does not lyse its own host following overexpression at 15°C and that the Lon protease is involved in this phenotype.
Collapse
|
5
|
Kong L, Liu J, Zheng X, Deng Z, You D. CtcS, a MarR family regulator, regulates chlortetracycline biosynthesis. BMC Microbiol 2019; 19:279. [PMID: 31823730 PMCID: PMC6905112 DOI: 10.1186/s12866-019-1670-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 12/01/2019] [Indexed: 01/08/2023] Open
Abstract
Background Chlortetracycline (CTC) is one of the commercially important tetracyclines (TCs) family product and is mainly produced by Streptomyces. CTC is still in a great demand due to its broad-spectrum activity against pathogens. Engineering transcriptional control allows the cell to allocate its valuable resources towards protein production and provides an important method for the build-up of desired metabolites. Despite extensive efforts concerning transcriptional regulation for increasing the productivities of TCs, the regulatory mechanisms of the CTC biosynthesis remain poorly understood. Results In this study, the possible regulatory function of CtcS, a potential member of MarR (multiple antibiotic resistance regulator) family of transcriptional regulators in S. aureofaciens F3, was demonstrated. Knockdown of ctcS altered the transcription of several biosynthesis-related genes and reduced the production of tetracycline (TC) and CTC, without obvious effect on morphological differentiation and cell growth. Especially, CtcS directly repressed the transcription of the adjacent divergent gene ctcR (which encodes a putative TC resistance efflux protein). A CtcS-binding site was identified within the promoter region of ctcR by DNase I footprinting and an inverted repeat (5′-CTTGTC-3′) composed of two 6-nt half sites in the protected region was found. Moreover, both CTC and TC could attenuate the binding activity of CtcS with target DNA. Conclusion ctcS regulated the production of TC and CTC in S. aureofaciens F3 and the overexpression of it could be used as a simple approach for the construction of engineering strain with higher productivity. Meanwhile, CtcS was characterized as a TC- and CTC-responsive MarR family regulator. This study provides a previously unrecognized function of CtcS and will benefit the research on the regulatory machinery of the MarR family regulators.
Collapse
Affiliation(s)
- Lingxin Kong
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Jia Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Xiaoqing Zheng
- Department of Immunology, Hebei Medical University, Shijiazhuang, 050017, Hebei, China
| | - Zixin Deng
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Delin You
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, China.
| |
Collapse
|
6
|
Phenotypic Diversification of Microbial Pathogens—Cooperating and Preparing for the Future. J Mol Biol 2019; 431:4645-4655. [DOI: 10.1016/j.jmb.2019.06.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Revised: 06/20/2019] [Accepted: 06/21/2019] [Indexed: 12/22/2022]
|
7
|
Kusmierek M, Hoßmann J, Witte R, Opitz W, Vollmer I, Volk M, Heroven AK, Wolf-Watz H, Dersch P. A bacterial secreted translocator hijacks riboregulators to control type III secretion in response to host cell contact. PLoS Pathog 2019; 15:e1007813. [PMID: 31173606 PMCID: PMC6583979 DOI: 10.1371/journal.ppat.1007813] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 06/19/2019] [Accepted: 05/02/2019] [Indexed: 02/05/2023] Open
Abstract
Numerous Gram-negative pathogens use a Type III Secretion System (T3SS) to promote virulence by injecting effector proteins into targeted host cells, which subvert host cell processes. Expression of T3SS and the effectors is triggered upon host cell contact, but the underlying mechanism is poorly understood. Here, we report a novel strategy of Yersinia pseudotuberculosis in which this pathogen uses a secreted T3SS translocator protein (YopD) to control global RNA regulators. Secretion of the YopD translocator upon host cell contact increases the ratio of post-transcriptional regulator CsrA to its antagonistic small RNAs CsrB and CsrC and reduces the degradosome components PNPase and RNase E levels. This substantially elevates the amount of the common transcriptional activator (LcrF) of T3SS/Yop effector genes and triggers the synthesis of associated virulence-relevant traits. The observed hijacking of global riboregulators allows the pathogen to coordinate virulence factor expression and also readjusts its physiological response upon host cell contact.
Collapse
Affiliation(s)
- Maria Kusmierek
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jörn Hoßmann
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Rebekka Witte
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Wiebke Opitz
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Vollmer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
| | - Marcel Volk
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Hans Wolf-Watz
- Department of Molecular Biology, Umea University, Sweden
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
- * E-mail:
| |
Collapse
|
8
|
Comparative Transcriptomic Profiling of Yersinia enterocolitica O:3 and O:8 Reveals Major Expression Differences of Fitness- and Virulence-Relevant Genes Indicating Ecological Separation. mSystems 2019; 4:mSystems00239-18. [PMID: 31020044 PMCID: PMC6478967 DOI: 10.1128/msystems.00239-18] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 02/27/2019] [Indexed: 01/16/2023] Open
Abstract
Yersinia enterocolitica is a major diarrheal pathogen and is associated with a large range of gut-associated diseases. Members of this species have evolved into different phylogroups with genotypic variations. We performed the first characterization of the Y. enterocolitica transcriptional landscape and tracked the consequences of the genomic variations between two different pathogenic phylogroups by comparing their RNA repertoire, promoter usage, and expression profiles under four different virulence-relevant conditions. Our analysis revealed major differences in the transcriptional outputs of the closely related strains, pointing to an ecological separation in which one is more adapted to an environmental lifestyle and the other to a mostly mammal-associated lifestyle. Moreover, a variety of pathoadaptive alterations, including alterations in acid resistance genes, colonization factors, and toxins, were identified which affect virulence and host specificity. This illustrates that comparative transcriptomics is an excellent approach to discover differences in the functional output from closely related genomes affecting niche adaptation and virulence, which cannot be directly inferred from DNA sequences. Yersinia enterocolitica is a zoonotic pathogen and an important cause of bacterial gastrointestinal infections in humans. Large-scale population genomic analyses revealed genetic and phenotypic diversity of this bacterial species, but little is known about the differences in the transcriptome organization, small RNA (sRNA) repertoire, and transcriptional output. Here, we present the first comparative high-resolution transcriptome analysis of Y. enterocolitica strains representing highly pathogenic phylogroup 2 (serotype O:8) and moderately pathogenic phylogroup 3 (serotype O:3) grown under four infection-relevant conditions. Our transcriptome sequencing (RNA-seq) approach revealed 1,299 and 1,076 transcriptional start sites and identified strain-specific sRNAs that could contribute to differential regulation among the phylogroups. Comparative transcriptomics further uncovered major gene expression differences, in particular, in the temperature-responsive regulon. Multiple virulence-relevant genes are differentially regulated between the two strains, supporting an ecological separation of phylogroups with certain niche-adapted properties. Strong upregulation of the ystA enterotoxin gene in combination with constitutive high expression of cell invasion factor InvA further showed that the toxicity of recent outbreak O:3 strains has increased. Overall, our report provides new insights into the specific transcriptome organization of phylogroups 2 and 3 and reveals gene expression differences contributing to the substantial phenotypic differences that exist between the lineages. IMPORTANCEYersinia enterocolitica is a major diarrheal pathogen and is associated with a large range of gut-associated diseases. Members of this species have evolved into different phylogroups with genotypic variations. We performed the first characterization of the Y. enterocolitica transcriptional landscape and tracked the consequences of the genomic variations between two different pathogenic phylogroups by comparing their RNA repertoire, promoter usage, and expression profiles under four different virulence-relevant conditions. Our analysis revealed major differences in the transcriptional outputs of the closely related strains, pointing to an ecological separation in which one is more adapted to an environmental lifestyle and the other to a mostly mammal-associated lifestyle. Moreover, a variety of pathoadaptive alterations, including alterations in acid resistance genes, colonization factors, and toxins, were identified which affect virulence and host specificity. This illustrates that comparative transcriptomics is an excellent approach to discover differences in the functional output from closely related genomes affecting niche adaptation and virulence, which cannot be directly inferred from DNA sequences.
Collapse
|
9
|
Thanikkal EJ, Gahlot DK, Liu J, Fredriksson Sundbom M, Gurung JM, Ruuth K, Francis MK, Obi IR, Thompson KM, Chen S, Dersch P, Francis MS. The Yersinia pseudotuberculosis Cpx envelope stress system contributes to transcriptional activation of rovM. Virulence 2019; 10:37-57. [PMID: 30518290 PMCID: PMC6298763 DOI: 10.1080/21505594.2018.1556151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The Gram-negative enteropathogen Yersinia pseudotuberculosis possesses a number of regulatory systems that detect cell envelope damage caused by noxious extracytoplasmic stresses. The CpxA sensor kinase and CpxR response regulator two-component regulatory system is one such pathway. Active Cpx signalling upregulates various factors designed to repair and restore cell envelope integrity. Concomitantly, this pathway also down-regulates key determinants of virulence. In Yersinia, cpxA deletion accumulates high levels of phosphorylated CpxR (CpxR~P). Accumulated CpxR~P directly repressed rovA expression and this limited expression of virulence-associated processes. A second transcriptional regulator, RovM, also negatively regulates rovA expression in response to nutrient stress. Hence, this study aimed to determine if CpxR~P can influence rovA expression through control of RovM levels. We determined that the active CpxR~P isoform bound to the promoter of rovM and directly induced its expression, which naturally associated with a concurrent reduction in rovA expression. Site-directed mutagenesis of the CpxR~P binding sequence in the rovM promoter region desensitised rovM expression to CpxR~P. These data suggest that accumulated CpxR~P inversely manipulates the levels of two global transcriptional regulators, RovA and RovM, and this would be expected to have considerable influence on Yersinia pathophysiology and metabolism.
Collapse
Affiliation(s)
- Edvin J Thanikkal
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | - Dharmender K Gahlot
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | - Junfa Liu
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | | | - Jyoti M Gurung
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | - Kristina Ruuth
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | - Monika K Francis
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | - Ikenna R Obi
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| | - Karl M Thompson
- c Department of Microbiology , College of Medicine, Howard University , Washington , DC , USA.,d Interdisciplinary Research Building , Howard University , Washington , DC , USA
| | - Shiyun Chen
- e Key Laboratory of Special Pathogens and Biosafety , Wuhan Institute of Virology, Chinese Academy of Sciences , Wuhan , China
| | - Petra Dersch
- f Department of Molecular Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Matthew S Francis
- a Department of Molecular Biology , Umeå University , Umeå , Sweden.,b Umeå Centre for Microbial Research , Umeå University , Umeå , Sweden
| |
Collapse
|
10
|
The stringent response factor, RelA, positively regulates T6SS4 expression through the RovM/RovA pathway in Yersinia pseudotuberculosis. Microbiol Res 2019; 220:32-41. [DOI: 10.1016/j.micres.2018.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 10/31/2018] [Accepted: 12/06/2018] [Indexed: 12/13/2022]
|
11
|
Phenotypic heterogeneity: a bacterial virulence strategy. Microbes Infect 2018; 20:570-577. [DOI: 10.1016/j.micinf.2018.01.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/15/2018] [Accepted: 01/17/2018] [Indexed: 11/21/2022]
|
12
|
Sadana P, Geyer R, Pezoldt J, Helmsing S, Huehn J, Hust M, Dersch P, Scrima A. The invasin D protein from Yersinia pseudotuberculosis selectively binds the Fab region of host antibodies and affects colonization of the intestine. J Biol Chem 2018. [PMID: 29535184 DOI: 10.1074/jbc.ra117.001068] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Yersinia pseudotuberculosis is a Gram-negative bacterium and zoonotic pathogen responsible for a wide range of diseases, ranging from mild diarrhea, enterocolitis, lymphatic adenitis to persistent local inflammation. The Y. pseudotuberculosis invasin D (InvD) molecule belongs to the invasin (InvA)-type autotransporter proteins, but its structure and function remain unknown. In this study, we present the first crystal structure of InvD, analyzed its expression and function in a murine infection model, and identified its target molecule in the host. We found that InvD is induced at 37 °C and expressed in vivo 2-4 days after infection, indicating that InvD is a virulence factor. During infection, InvD was expressed in all parts of the intestinal tract, but not in deeper lymphoid tissues. The crystal structure of the C-terminal adhesion domain of InvD revealed a distinct Ig-related fold that, apart from the canonical β-sheets, comprises various modifications of and insertions into the Ig-core structure. We identified the Fab fragment of host-derived IgG/IgA antibodies as the target of the adhesion domain. Phage display panning and flow cytometry data further revealed that InvD exhibits a preferential binding specificity toward antibodies with VH3/VK1 variable domains and that it is specifically recruited to a subset of B cells. This finding suggests that InvD modulates Ig functions in the intestine and affects direct interactions with a subset of cell surface-exposed B-cell receptors. In summary, our results provide extensive insights into the structure of InvD and its specific interaction with the target molecule in the host.
Collapse
Affiliation(s)
- Pooja Sadana
- From the Young Investigator Group Structural Biology of Autophagy, Department of Structure and Function of Proteins
| | | | - Joern Pezoldt
- Experimental Immunology, Helmholtz-Centre for Infection Research, 38124 Braunschweig and
| | - Saskia Helmsing
- the Institute of Biochemistry, Biotechnology and Bioinformatics, Technische Universität, 38106 Braunschweig, Germany
| | - Jochen Huehn
- Experimental Immunology, Helmholtz-Centre for Infection Research, 38124 Braunschweig and
| | - Michael Hust
- the Institute of Biochemistry, Biotechnology and Bioinformatics, Technische Universität, 38106 Braunschweig, Germany
| | - Petra Dersch
- the Departments of Molecular Infection Biology and
| | - Andrea Scrima
- From the Young Investigator Group Structural Biology of Autophagy, Department of Structure and Function of Proteins,
| |
Collapse
|
13
|
Heine W, Beckstette M, Heroven AK, Thiemann S, Heise U, Nuss AM, Pisano F, Strowig T, Dersch P. Loss of CNFY toxin-induced inflammation drives Yersinia pseudotuberculosis into persistency. PLoS Pathog 2018; 14:e1006858. [PMID: 29390040 PMCID: PMC5811047 DOI: 10.1371/journal.ppat.1006858] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 02/13/2018] [Accepted: 01/05/2018] [Indexed: 12/16/2022] Open
Abstract
Gastrointestinal infections caused by enteric yersiniae can become persistent and complicated by relapsing enteritis and severe autoimmune disorders. To establish a persistent infection, the bacteria have to cope with hostile surroundings when they transmigrate through the intestinal epithelium and colonize underlying gut-associated lymphatic tissues. How the bacteria gain a foothold in the face of host immune responses is poorly understood. Here, we show that the CNFY toxin, which enhances translocation of the antiphagocytic Yop effectors, induces inflammatory responses. This results in extensive tissue destruction, alteration of the intestinal microbiota and bacterial clearance. Suppression of CNFY function, however, increases interferon-γ-mediated responses, comprising non-inflammatory antimicrobial activities and tolerogenesis. This process is accompanied by a preterm reprogramming of the pathogen's transcriptional response towards persistence, which gives the bacteria a fitness edge against host responses and facilitates establishment of a commensal-type life style.
Collapse
Affiliation(s)
- Wiebke Heine
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michael Beckstette
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sophie Thiemann
- Group Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ulrike Heise
- Group Mouse Pathology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Aaron Mischa Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Fabio Pisano
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Till Strowig
- Group Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| |
Collapse
|
14
|
Kim J, Fukuto HS, Brown DA, Bliska JB, London E. Effects of host cell sterol composition upon internalization of Yersinia pseudotuberculosis and clustered β1 integrin. J Biol Chem 2017; 293:1466-1479. [PMID: 29197826 DOI: 10.1074/jbc.m117.811224] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 11/29/2017] [Indexed: 11/06/2022] Open
Abstract
Yersinia pseudotuberculosis is a foodborne pathogenic bacterium that causes acute gastrointestinal illness, but its mechanisms of infection are incompletely described. We examined how host cell sterol composition affected Y. pseudotuberculosis uptake. To do this, we depleted or substituted cholesterol in human MDA-MB-231 epithelial cells with various alternative sterols. Decreasing host cell cholesterol significantly reduced pathogen internalization. When host cell cholesterol was substituted with various sterols, only desmosterol and 7-dehydrocholesterol supported internalization. This specificity was not due to sterol dependence of bacterial attachment to host cells, which was similar with all sterols studied. Because a key step in Y. pseudotuberculosis internalization is interaction of the bacterial adhesins invasin and YadA with host cell β1 integrin, we compared the sterol dependence of wildtype Y. pseudotuberculosis internalization with that of Δinv, ΔyadA, and ΔinvΔyadA mutant strains. YadA deletion decreased bacterial adherence to host cells, whereas invasin deletion had no effect. Nevertheless, host cell sterol substitution had a similar effect on internalization of these bacterial deletion strains as on the wildtype bacteria. The ΔinvΔyadA double mutant adhered least to cells and so was not significantly internalized. The sterol structure dependence of Y. pseudotuberculosis internalization differed from that of endocytosis, as monitored using antibody-clustered β1 integrin and previous studies on other proteins, which had a more permissive sterol dependence. This study suggests that agents could be designed to interfere with internalization of Yersinia without disturbing endocytosis.
Collapse
Affiliation(s)
- JiHyun Kim
- From the Departments of Biochemistry and Cell Biology and
| | - Hana S Fukuto
- Molecular Genetics and Microbiology and.,Center for Infectious Diseases, Stony Brook University, Stony Brook, New York 11794
| | | | - James B Bliska
- Molecular Genetics and Microbiology and.,Center for Infectious Diseases, Stony Brook University, Stony Brook, New York 11794
| | - Erwin London
- From the Departments of Biochemistry and Cell Biology and
| |
Collapse
|
15
|
Nuss AM, Schuster F, Roselius L, Klein J, Bücker R, Herbst K, Heroven AK, Pisano F, Wittmann C, Münch R, Müller J, Jahn D, Dersch P. A Precise Temperature-Responsive Bistable Switch Controlling Yersinia Virulence. PLoS Pathog 2016; 12:e1006091. [PMID: 28006011 PMCID: PMC5179001 DOI: 10.1371/journal.ppat.1006091] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 11/27/2016] [Indexed: 11/19/2022] Open
Abstract
Different biomolecules have been identified in bacterial pathogens that sense changes in temperature and trigger expression of virulence programs upon host entry. However, the dynamics and quantitative outcome of this response in individual cells of a population, and how this influences pathogenicity are unknown. Here, we address these questions using a thermosensing virulence regulator of an intestinal pathogen (RovA of Yersinia pseudotuberculosis) as a model. We reveal that this regulator is part of a novel thermoresponsive bistable switch, which leads to high- and low-invasive subpopulations within a narrow temperature range. The temperature range in which bistability is observed is defined by the degradation and synthesis rate of the regulator, and is further adjustable via a nutrient-responsive regulator. The thermoresponsive switch is also characterized by a hysteretic behavior in which activation and deactivation occurred on vastly different time scales. Mathematical modeling accurately mirrored the experimental behavior and predicted that the thermoresponsiveness of this sophisticated bistable switch is mainly determined by the thermo-triggered increase of RovA proteolysis. We further observed RovA ON and OFF subpopulations of Y. pseudotuberculosis in the Peyer’s patches and caecum of infected mice, and that changes in the RovA ON/OFF cell ratio reduce tissue colonization and overall virulence. This points to a bet-hedging strategy in which the thermoresponsive bistable switch plays a key role in adapting the bacteria to the fluctuating conditions encountered as they pass through the host’s intestinal epithelium and suggests novel strategies for the development of antimicrobial therapies. The ability of pathogens to sense temperature changes when they enter their mammalian hosts from the environment is crucial to optimize their fitness and adjust expression of their virulence programs. Until now it has been assumed that all cells within a population participate in the thermo-triggered adaptive response. Here, we show that a small subpopulation of an enteric pathogen does not follow thermo-induced reprogramming when the bacteria pass the intestinal epithelial layer. Observed heterogeneity is promoted by a new type of bistable switch, implicating a highly precise, thermoresponsive control element. Moreover, we demonstrate that this regulatory implement is important for virulence as it prepares the pathogen for sudden, unpredictable fluctuations encountered during host entry and exit.
Collapse
Affiliation(s)
- Aaron Mischa Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Franziska Schuster
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Louisa Roselius
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - Johannes Klein
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - René Bücker
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Katharina Herbst
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Fabio Pisano
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, Saarbrücken, Germany
| | - Richard Münch
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - Johannes Müller
- Institute of Mathematics, Technical University Munich, Munich, Germany
- Institute of Computational Biology, Helmholtz Centre Munich, Neuherberg, Germany
| | - Dieter Jahn
- Institute of Microbiology, Technical University Braunschweig, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- * E-mail:
| |
Collapse
|
16
|
Nuss AM, Heroven AK, Dersch P. RNA Regulators: Formidable Modulators of Yersinia Virulence. Trends Microbiol 2016; 25:19-34. [PMID: 27651123 DOI: 10.1016/j.tim.2016.08.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2016] [Revised: 08/08/2016] [Accepted: 08/24/2016] [Indexed: 10/21/2022]
Abstract
A large repertoire of RNA-based regulatory mechanisms, including a plethora of cis- and trans-acting noncoding RNAs (ncRNAs), sensory RNA elements, regulatory RNA-binding proteins, and RNA-degrading enzymes have been uncovered lately as key players in the regulation of metabolism, stress responses, and virulence of the genus Yersinia. Many of them are strictly controlled in response to fluctuating environmental conditions sensed during the course of the infection, and certain riboregulators have already been shown to be crucial for virulence. Some of them are highly conserved among the family Enterobacteriaceae, while others are genus-, species-, or strain-specific and could contribute to the difference in Yersinia pathogenicity. Importantly, the analysis of Yersinia riboregulators has not only uncovered crucial elements and regulatory mechanisms governing host-pathogen interactions, it also revealed exciting new venues for the design of novel anti-infectives.
Collapse
Affiliation(s)
- Aaron M Nuss
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
| |
Collapse
|
17
|
Roy A, Reddi R, Sawhney B, Ghosh DK, Addlagatta A, Ranjan A. Expression, Functional Characterization and X-ray Analysis of HosA, A Member of MarR Family of Transcription Regulator from Uropathogenic Escherichia coli. Protein J 2016; 35:269-82. [DOI: 10.1007/s10930-016-9670-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
18
|
Abstract
The human pathogens
Yersinia pseudotuberculosis and
Yersinia enterocolitica cause enterocolitis, while
Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.
Collapse
Affiliation(s)
- Steve Atkinson
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Paul Williams
- Centre for Biomolecular Sciences, School of Life Sciences, University of Nottingham, Nottingham, UK
| |
Collapse
|
19
|
Chauhan N, Wrobel A, Skurnik M, Leo JC. Yersinia adhesins: An arsenal for infection. Proteomics Clin Appl 2016; 10:949-963. [PMID: 27068449 DOI: 10.1002/prca.201600012] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 03/14/2016] [Accepted: 04/06/2016] [Indexed: 11/09/2022]
Abstract
The Yersiniae are a group of Gram-negative coccobacilli inhabiting a wide range of habitats. The genus harbors three recognized human pathogens: Y. enterocolitica and Y. pseudotuberculosis, which both cause gastrointestinal disease, and Y. pestis, the causative agent of plague. These three organisms have served as models for a number of aspects of infection biology, including adhesion, immune evasion, evolution of pathogenic traits, and retracing the course of ancient pandemics. The virulence of the pathogenic Yersiniae is heavily dependent on a number of adhesin molecules. Some of these, such as the Yersinia adhesin A and invasin of the enteropathogenic species, and the pH 6 antigen of Y. pestis, have been extensively studied. However, genomic sequencing has uncovered a host of other adhesins present in these organisms, the functions of which are only starting to be investigated. Here, we review the current state of knowledge on the adhesin molecules present in the Yersiniae, and their functions and putative roles in the infection process.
Collapse
Affiliation(s)
- Nandini Chauhan
- Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Agnieszka Wrobel
- Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Mikael Skurnik
- Department of Bacteriology and Immunology, Medicum, Research Programs Unit, Immunobiology, University of Helsinki, Helsinki, Finland.,Central Hospital Laboratory Diagnostics, Helsinki University, Helsinki, Finland
| | - Jack C Leo
- Evolution and Genetics, Department of Biosciences, University of Oslo, Oslo, Norway.
| |
Collapse
|
20
|
Chen S, Thompson KM, Francis MS. Environmental Regulation of Yersinia Pathophysiology. Front Cell Infect Microbiol 2016; 6:25. [PMID: 26973818 PMCID: PMC4773443 DOI: 10.3389/fcimb.2016.00025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 02/15/2016] [Indexed: 12/26/2022] Open
Abstract
Hallmarks of Yersinia pathogenesis include the ability to form biofilms on surfaces, the ability to establish close contact with eukaryotic target cells and the ability to hijack eukaryotic cell signaling and take over control of strategic cellular processes. Many of these virulence traits are already well-described. However, of equal importance is knowledge of both confined and global regulatory networks that collaborate together to dictate spatial and temporal control of virulence gene expression. This review has the purpose to incorporate historical observations with new discoveries to provide molecular insight into how some of these regulatory mechanisms respond rapidly to environmental flux to govern tight control of virulence gene expression by pathogenic Yersinia.
Collapse
Affiliation(s)
- Shiyun Chen
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences Wuhan, China
| | - Karl M Thompson
- Department of Microbiology, College of Medicine, Howard University Washington, DC, USA
| | - Matthew S Francis
- Umeå Centre for Microbial Research, Umeå UniversityUmeå, Sweden; Department of Molecular Biology, Umeå UniversityUmeå, Sweden
| |
Collapse
|
21
|
Abstract
Y. pestis exhibits dramatically different traits of pathogenicity and transmission, albeit their close genetic relationship with its ancestor-Y. pseudotuberculosis, a self-limiting gastroenteric pathogen. Y. pestis is evolved into a deadly pathogen and transmitted to mammals and/or human beings by infected flea biting or directly contacting with the infected animals. Various kinds of environmental changes are implicated into its complex life cycle and pathogenesis. Dynamic regulation of gene expression is critical for environmental adaptation or survival, primarily reflected by genetic regulation mediated by transcriptional factors and small regulatory RNAs at the transcriptional and posttranscriptional level, respectively. The effects of genetic regulation have been shown to profoundly influence Y. pestis physiology and pathogenesis such as stress resistance, biofilm formation, intracellular survival, and replication. In this chapter, we mainly summarize the progresses on popular methods of genetic regulation and on regulatory patterns and consequences of many key transcriptional and posttranscriptional regulators, with a particular emphasis on how genetic regulation influences the biofilm and virulence of Y. pestis.
Collapse
|
22
|
Martínez-Chavarría LC, Vadyvaloo V. Yersinia pestis and Yersinia pseudotuberculosis infection: a regulatory RNA perspective. Front Microbiol 2015; 6:956. [PMID: 26441890 PMCID: PMC4585118 DOI: 10.3389/fmicb.2015.00956] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 08/28/2015] [Indexed: 12/27/2022] Open
Abstract
Yersinia pestis, responsible for causing fulminant plague, has evolved clonally from the enteric pathogen, Y. pseudotuberculosis, which in contrast, causes a relatively benign enteric illness. An ~97% nucleotide identity over 75% of their shared protein coding genes is maintained between these two pathogens, leaving much conjecture regarding the molecular determinants responsible for producing these vastly different disease etiologies, host preferences and transmission routes. One idea is that coordinated production of distinct factors required for host adaptation and virulence in response to specific environmental cues could contribute to the distinct pathogenicity distinguishing these two species. Small non-coding RNAs that direct posttranscriptional regulation have recently been identified as key molecules that may provide such timeous expression of appropriate disease enabling factors. Here the burgeoning field of small non-coding regulatory RNAs in Yersinia pathogenesis is reviewed from the viewpoint of adaptive colonization, virulence and divergent evolution of these pathogens.
Collapse
Affiliation(s)
- Luary C Martínez-Chavarría
- Departamento de Patología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, México Mexico
| | - Viveka Vadyvaloo
- Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA USA
| |
Collapse
|
23
|
Erhardt M, Dersch P. Regulatory principles governing Salmonella and Yersinia virulence. Front Microbiol 2015; 6:949. [PMID: 26441883 PMCID: PMC4563271 DOI: 10.3389/fmicb.2015.00949] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 08/27/2015] [Indexed: 11/13/2022] Open
Abstract
Enteric pathogens such as Salmonella and Yersinia evolved numerous strategies to survive and proliferate in different environmental reservoirs and mammalian hosts. Deciphering common and pathogen-specific principles for how these bacteria adjust and coordinate spatiotemporal expression of virulence determinants, stress adaptation, and metabolic functions is fundamental to understand microbial pathogenesis. In order to manage sudden environmental changes, attacks by the host immune systems and microbial competition, the pathogens employ a plethora of transcriptional and post-transcriptional control elements, including transcription factors, sensory and regulatory RNAs, RNAses, and proteases, to fine-tune and control complex gene regulatory networks. Many of the contributing global regulators and the molecular mechanisms of regulation are frequently conserved between Yersinia and Salmonella. However, the interplay, arrangement, and composition of the control elements vary between these closely related enteric pathogens, which generate phenotypic differences leading to distinct pathogenic properties. In this overview we present common and different regulatory networks used by Salmonella and Yersinia to coordinate the expression of crucial motility, cell adhesion and invasion determinants, immune defense strategies, and metabolic adaptation processes. We highlight evolutionary changes of the gene regulatory circuits that result in different properties of the regulatory elements and how this influences the overall outcome of the infection process.
Collapse
Affiliation(s)
- Marc Erhardt
- Young Investigator Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research Braunschweig, Germany
| |
Collapse
|
24
|
Abstract
Pathogenic bacteria sense environmental cues, including the local temperature, to control the production of key virulence factors. Thermal regulation can be achieved at the level of DNA, RNA or protein and although many virulence factors are subject to thermal regulation, the exact mechanisms of control are yet to be elucidated in many instances. Understanding how virulence factors are regulated by temperature presents a significant challenge, as gene expression and protein production are often influenced by complex regulatory networks involving multiple transcription factors in bacteria. Here we highlight some recent insights into thermal regulation of virulence in pathogenic bacteria. We focus on bacteria which cause disease in mammalian hosts, which are at a significantly higher temperature than the outside environment. We outline the mechanisms of thermal regulation and how understanding this fundamental aspect of the biology of bacteria has implications for pathogenesis and human health.
Collapse
Affiliation(s)
- Oliver Lam
- a The Sir William Dunn School of Pathology ; University of Oxford ; Oxford , UK
| | | | | |
Collapse
|
25
|
Vakulskas CA, Potts AH, Babitzke P, Ahmer BMM, Romeo T. Regulation of bacterial virulence by Csr (Rsm) systems. Microbiol Mol Biol Rev 2015; 79:193-224. [PMID: 25833324 PMCID: PMC4394879 DOI: 10.1128/mmbr.00052-14] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Most bacterial pathogens have the remarkable ability to flourish in the external environment and in specialized host niches. This ability requires their metabolism, physiology, and virulence factors to be responsive to changes in their surroundings. It is no surprise that the underlying genetic circuitry that supports this adaptability is multilayered and exceedingly complex. Studies over the past 2 decades have established that the CsrA/RsmA proteins, global regulators of posttranscriptional gene expression, play important roles in the expression of virulence factors of numerous proteobacterial pathogens. To accomplish these tasks, CsrA binds to the 5' untranslated and/or early coding regions of mRNAs and alters translation, mRNA turnover, and/or transcript elongation. CsrA activity is regulated by noncoding small RNAs (sRNAs) that contain multiple CsrA binding sites, which permit them to sequester multiple CsrA homodimers away from mRNA targets. Environmental cues sensed by two-component signal transduction systems and other regulatory factors govern the expression of the CsrA-binding sRNAs and, ultimately, the effects of CsrA on secretion systems, surface molecules and biofilm formation, quorum sensing, motility, pigmentation, siderophore production, and phagocytic avoidance. This review presents the workings of the Csr system, the paradigm shift that it generated for understanding posttranscriptional regulation, and its roles in virulence networks of animal and plant pathogens.
Collapse
Affiliation(s)
- Christopher A Vakulskas
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Anastasia H Potts
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania, USA
| | - Brian M M Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, Ohio, USA Department of Microbiology, The Ohio State University, Columbus, Ohio, USA
| | - Tony Romeo
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
26
|
SlyA regulates motA and motB, virulence and stress-related genes under conditions induced by the PhoP-PhoQ system in Dickeya dadantii 3937. Res Microbiol 2015; 166:467-75. [PMID: 26027774 DOI: 10.1016/j.resmic.2015.05.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 05/01/2015] [Accepted: 05/11/2015] [Indexed: 12/31/2022]
Abstract
We previously showed that SlyA of Dickeya dadantii 3937 plays an important role in virulence toward plants, and that the ΔslyA mutant is hypermotile, whereas flagellum synthesis and flagellin production are indistinguishable from the wild type. Here we show that motility factors, including the distance of continuous directed movement, time for that movement and speed, were significantly higher in the ΔslyA mutant than in the wild type. Remarkably, transcription levels of motA and motB, that are involved in flagellar rotation, were elevated in the ΔslyA mutant, suggesting that the mutant's hypermotility was due to an increase in flagellar rotation. In low (10 μM) magnesium medium that activates the PhoP-PhoQ system, growth and virulence of the ΔslyA mutant were much lower than for the wild type; expression of motA, motB, mgtA, pelA, pelB, pelC, pelD, pelE, pelI, indA, tolC, sodC, acsA and hrpN were also reduced in the mutant. Interestingly, motA, motB, pelD, pelE, pelI, sodC and indA were also reduced in phoP and phoQ mutants. Because the SlyA protein directly binds to the promoter region of PhoP, SlyA regulates virulence by controlling multiple pathogenicity-related genes directly and/or at least by controlling PhoP in D. dadantii 3937 when magnesium is low.
Collapse
|
27
|
Heroven AK, Böhme K, Dersch P. The Csr/Rsm system of Yersinia and related pathogens. RNA Biol 2014; 9:379-91. [DOI: 10.4161/rna.19333] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
|
28
|
Heroven AK, Dersch P. Coregulation of host-adapted metabolism and virulence by pathogenic yersiniae. Front Cell Infect Microbiol 2014; 4:146. [PMID: 25368845 PMCID: PMC4202721 DOI: 10.3389/fcimb.2014.00146] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 09/30/2014] [Indexed: 01/07/2023] Open
Abstract
Deciphering the principles how pathogenic bacteria adapt their metabolism to a specific host microenvironment is critical for understanding bacterial pathogenesis. The enteric pathogenic Yersinia species Yersinia pseudotuberculosis and Yersinia enterocolitica and the causative agent of plague, Yersinia pestis, are able to survive in a large variety of environmental reservoirs (e.g., soil, plants, insects) as well as warm-blooded animals (e.g., rodents, pigs, humans) with a particular preference for lymphatic tissues. In order to manage rapidly changing environmental conditions and interbacterial competition, Yersinia senses the nutritional composition during the course of an infection by special molecular devices, integrates this information and adapts its metabolism accordingly. In addition, nutrient availability has an impact on expression of virulence genes in response to C-sources, demonstrating a tight link between the pathogenicity of yersiniae and utilization of nutrients. Recent studies revealed that global regulatory factors such as the cAMP receptor protein (Crp) and the carbon storage regulator (Csr) system are part of a large network of transcriptional and posttranscriptional control strategies adjusting metabolic changes and virulence in response to temperature, ion and nutrient availability. Gained knowledge about the specific metabolic requirements and the correlation between metabolic and virulence gene expression that enable efficient host colonization led to the identification of new potential antimicrobial targets.
Collapse
Affiliation(s)
- Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Institut für Mikrobiology, Technische Universität Braunschweig Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Institut für Mikrobiology, Technische Universität Braunschweig Braunschweig, Germany
| |
Collapse
|
29
|
Bücker R, Heroven AK, Becker J, Dersch P, Wittmann C. The pyruvate-tricarboxylic acid cycle node: a focal point of virulence control in the enteric pathogen Yersinia pseudotuberculosis. J Biol Chem 2014; 289:30114-32. [PMID: 25164818 DOI: 10.1074/jbc.m114.581348] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Despite our increasing knowledge of the specific pathogenicity factors in bacteria, the contribution of metabolic processes to virulence is largely unknown. Here, we elucidate a tight connection between pathogenicity and core metabolism in the enteric pathogen Yersinia pseudotuberculosis by integrated transcriptome and [(13)C]fluxome analysis of the wild type and virulence-regulator mutants. During aerobic growth on glucose, Y. pseudotuberculosis reveals an unusual flux distribution with a high level of secreted pyruvate. The absence of the transcriptional and post-transcriptional regulators RovA, CsrA, and Crp strongly perturbs the fluxes of carbon core metabolism at the level of pyruvate metabolism and the tricarboxylic acid (TCA) cycle, and these perturbations are accompanied by transcriptional changes in the corresponding enzymes. Knock-outs of regulators of this metabolic branch point and of its central enzyme, pyruvate kinase (ΔpykF), result in mutants with significantly reduced virulence in an oral mouse infection model. In summary, our work identifies the pyruvate-TCA cycle node as a focal point for controlling the host colonization and virulence of Yersinia.
Collapse
Affiliation(s)
- René Bücker
- From the Institute of Systems Biotechnology, Saarland University, 66123 Saarbrücken, the Institute of Biochemical Engineering, Technische Universität, Braunschweig and
| | - Ann Kathrin Heroven
- the Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Judith Becker
- From the Institute of Systems Biotechnology, Saarland University, 66123 Saarbrücken
| | - Petra Dersch
- the Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, 38124 Braunschweig, Germany
| | - Christoph Wittmann
- From the Institute of Systems Biotechnology, Saarland University, 66123 Saarbrücken,
| |
Collapse
|
30
|
Influence of PhoP and intra-species variations on virulence of Yersinia pseudotuberculosis during the natural oral infection route. PLoS One 2014; 9:e103541. [PMID: 25075520 PMCID: PMC4116203 DOI: 10.1371/journal.pone.0103541] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 07/03/2014] [Indexed: 01/02/2023] Open
Abstract
The two-component regulatory system PhoP/PhoQ has been shown to (i) control expression of virulence-associated traits, (ii) confer survival and growth within macrophages and (iii) play a role in Yersinia infections. However, the influence of PhoP on virulence varied greatly between different murine models of infection and its role in natural oral infections with frequently used representative isolates of Y. pseudotuberculosis was unknown. To address this issue, we constructed an isogenic set of phoP+ and phoP− variants of strain IP32953 and YPIII and analyzed the impact of PhoP using in vitro functionality experiments and a murine oral infection model, whereby we tested for bacterial dissemination and influence on the host immune response. Our results revealed that PhoP has a low impact on virulence, lymphatic and systemic organ colonization, and on immune response modulation by IP32953 and YPIII, indicating that PhoP is not absolutely essential for oral infections but may be involved in fine-tuning the outcome. Our work further revealed certain strain-specific differences in virulence properties, which do not strongly rely on the function of PhoP, but affect tissue colonization, dissemination and/or persistence of the bacteria. Highlighted intra-species variations may provide a potential means to rapidly adjust to environmental changes inside and outside of the host.
Collapse
|
31
|
Nuss AM, Schuster F, Kathrin Heroven A, Heine W, Pisano F, Dersch P. A direct link between the global regulator PhoP and the Csr regulon in Y. pseudotuberculosis through the small regulatory RNA CsrC. RNA Biol 2014; 11:580-93. [PMID: 24786463 DOI: 10.4161/rna.28676] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
In this study we investigated the influence of the global response regulator PhoP on the complex regulatory cascade controlling expression of early stage virulence genes of Yersinia pseudotuberculosis via the virulence regulator RovA. Our analysis revealed the following novel features: (1) PhoP activates expression of the CsrC RNA in Y. pseudotuberculosis, leading to activation of RovA synthesis through the CsrABC-RovM cascade, (2) activation of csrC transcription is direct and PhoP is shown to bind to two separate PhoP box-like sites, (3) PhoP-mediated activation results in transcription from two different promoters closely downstream of the PhoP binding sites, leading to two distinct CsrC RNAs, and (4) the stability of the CsrC RNAs differs significantly between the Y. pseudotuberculosis strains YPIII and IP32953 due to a 20 nucleotides insertion in CsrC(IP32953), which renders the transcript more susceptible to degradation. In summary, our study showed that PhoP-mediated influence on the regulatory cascade controlling the Csr system and RovA in Y. pseudotuberculosis varies within the species, suggesting that the Csr system is a focal point to readjust and adapt the genus to different hosts and reservoirs.
Collapse
Affiliation(s)
- Aaron M Nuss
- Department of Molecular Infection Biology; Helmholtz Centre for Infection Research; Braunschweig, Germany
| | - Franziska Schuster
- Department of Molecular Infection Biology; Helmholtz Centre for Infection Research; Braunschweig, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology; Helmholtz Centre for Infection Research; Braunschweig, Germany
| | - Wiebke Heine
- Department of Molecular Infection Biology; Helmholtz Centre for Infection Research; Braunschweig, Germany
| | - Fabio Pisano
- Department of Molecular Infection Biology; Helmholtz Centre for Infection Research; Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology; Helmholtz Centre for Infection Research; Braunschweig, Germany
| |
Collapse
|
32
|
Starke M, Fuchs TM. YmoA negatively controls the expression of insecticidal genes in Yersinia enterocolitica. Mol Microbiol 2014; 92:287-301. [PMID: 24548183 DOI: 10.1111/mmi.12554] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/13/2014] [Indexed: 11/28/2022]
Abstract
Yersinia enterocolitica is toxic towards invertebrates due to the presence of the toxin complex (tc) genes that are activated by the thermolabile regulator TcaR2. In the search for further regulatory factors involved in insecticidal gene expression, the modulator of yersinial virulence, YmoA, was identified to silence all tc genes of the Y. enterocolitica strain W22703 (biovar 2, serovar O:9). Using promoter fusions with the luciferase reporter, we found that the deletion of ymoA results in elevated transcription of tcaR1, tcaR2, tcaA, tcaB, tcaC, tccC1 and tccC2 at both 15 °C and 37 °C. Complementation by episomal ymoA significantly reduced tc gene expression, thus validating the inhibitory activity of YmoA on the production of insecticidal proteins. YmoA contributes to the binding properties of H-NS to the tc promoters by forming a complex with this nucleoid-associated protein, and this complex not only binds to the upstream regions of all tc genes, but also to intragenic sites of tcaA and tcaB that play an important role in controlling the expression of both genes. At low temperature, the intracellular amount of thermostable YmoA is not reduced, but the repressor is less functional. These data point to H-NS/YmoA as an antagonist of the inducer TcaR2.
Collapse
Affiliation(s)
- Mandy Starke
- Lehrstuhl für Mikrobielle Ökologie, Department für biowissenschaftliche Grundlagen, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany
| | | |
Collapse
|
33
|
Essential role of invasin for colonization and persistence of Yersinia enterocolitica in its natural reservoir host, the pig. Infect Immun 2013; 82:960-9. [PMID: 24343656 DOI: 10.1128/iai.01001-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, an oral minipig infection model was established to investigate the pathogenicity of Yersinia enterocolitica bioserotype 4/O:3. O:3 strains are highly prevalent in pigs, which are usually symptomless carriers, and they represent the most common cause of human yersiniosis. To assess the pathogenic potential of the O:3 serotype, we compared the colonization properties of Y. enterocolitica O:3 with O:8, a highly mouse-virulent Y. enterocolitica serotype, in minipigs and mice. We found that O:3 is a significantly better colonizer of swine than is O:8. Coinfection studies with O:3 mutant strains demonstrated that small variations within the O:3 genome leading to higher amounts of the primary adhesion factor invasin (InvA) improved colonization and/or survival of this serotype in swine but had only a minor effect on the colonization of mice. We further demonstrated that a deletion of the invA gene abolished long-term colonization in the pigs. Our results indicate a primary role for invasin in naturally occurring Y. enterocolitica O:3 infections in pigs and reveal a higher adaptation of O:3 than O:8 strains to their natural pig reservoir host.
Collapse
|
34
|
Schweer J, Kulkarni D, Kochut A, Pezoldt J, Pisano F, Pils MC, Genth H, Huehn J, Dersch P. The cytotoxic necrotizing factor of Yersinia pseudotuberculosis (CNFY) enhances inflammation and Yop delivery during infection by activation of Rho GTPases. PLoS Pathog 2013; 9:e1003746. [PMID: 24244167 PMCID: PMC3820761 DOI: 10.1371/journal.ppat.1003746] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 09/20/2013] [Indexed: 12/19/2022] Open
Abstract
Some isolates of Yersinia pseudotuberculosis produce the cytotoxic necrotizing factor (CNFY), but the functional consequences of this toxin for host-pathogen interactions during the infection are unknown. In the present study we show that CNFY has a strong influence on virulence. We demonstrate that the CNFY toxin is thermo-regulated and highly expressed in all colonized lymphatic tissues and organs of orally infected mice. Most strikingly, we found that a cnfY knock-out variant of a naturally toxin-expressing Y. pseudotuberculosis isolate is strongly impaired in its ability to disseminate into the mesenteric lymph nodes, liver and spleen, and has fully lost its lethality. The CNFY toxin contributes significantly to the induction of acute inflammatory responses and to the formation of necrotic areas in infected tissues. The analysis of the host immune response demonstrated that presence of CNFY leads to a strong reduction of professional phagocytes and natural killer cells in particular in the spleen, whereas loss of the toxin allows efficient tissue infiltration of these immune cells and rapid killing of the pathogen. Addition of purified CNFY triggers formation of actin-rich membrane ruffles and filopodia, which correlates with the activation of the Rho GTPases, RhoA, Rac1 and Cdc42. The analysis of type III effector delivery into epithelial and immune cells in vitro and during the course of the infection further demonstrated that CNFY enhances the Yop translocation process and supports a role for the toxin in the suppression of the antibacterial host response. In summary, we highlight the importance of CNFY for pathogenicity by showing that this toxin modulates inflammatory responses, protects the bacteria from attacks of innate immune effectors and enhances the severity of a Yersinia infection. Various toxins and effector proteins of bacterial pathogens have been found to manipulate eukaryotic cell machineries to promote persistence and proliferation within their hosts. Many of these virulence factors target small Rho GTPases, but their role in pathogenesis is often unknown. Here, we addressed the expression and functional consequences of the CNFY toxin found in some isolates of Y. pseudotuberculosis. We found that CNFY besides modulating the cell cytoskeleton by activation of the GTPases RhoA, Rac1 and Cdc42, contributes to increased inflammation and tissue damage. Moreover, CNFY increases the ability of Yersinia to prevent the attack of the immune system, by enhancing the delivery of antiphagocytic and cytotoxic effectors into professional phagocytes. Our findings provide the first insights into the multi-functional action and severe consequences of the CNFY toxin on the inflammatory response and disease-associated tissue damage during the natural course of the infection.
Collapse
Affiliation(s)
- Janina Schweer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Devesha Kulkarni
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Annika Kochut
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Joern Pezoldt
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Fabio Pisano
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Marina C. Pils
- Mouse Pathology, Animal Experimental Unit, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Harald Genth
- Institute for Toxicology, Medical School Hannover, Hannover, Germany
| | - Jochen Huehn
- Department of Experimental Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- * E-mail:
| |
Collapse
|
35
|
Abstract
The transcriptional regulator RovA positively regulates transcription of the Yersinia enterocolitica virulence gene inv. Invasin, encoded by inv, is important for establishment of Y. enterocolitica infection. However, a rovA mutant is more attenuated for virulence than an inv mutant, implying that RovA regulates additional virulence genes. When the Y. enterocolitica RovA regulon was defined by microarray analysis, YE1984 and YE1985 were among the genes identified as being upregulated by RovA. Since these genes are homologous to Xenorhabdus nematophila cytotoxin genes xaxA and xaxB, we named them yaxA and yaxB, respectively. In this work, we demonstrate the effects of YaxAB on the course of infection in the murine model. While a yaxAB mutant (ΔyaxAB) is capable of colonizing mice at the same level as the wild type, it slightly delays the course of infection and results in differing pathology in the spleen. Further, we found that yaxAB encode a probable cytotoxin capable of lysing mammalian cells, that both YaxA and YaxB are required for cytotoxic activity, and that the two proteins associate. YaxAB-mediated cell death occurs via osmotic lysis through the formation of distinct membrane pores. In silico tertiary structural analysis identified predicted structural homology between YaxA and proteins in pore-forming toxin complexes from Bacillus cereus (HBL-B) and Escherichia coli (HlyE). Thus, it appears that YaxAB function as virulence factors by inducing cell lysis through the formation of pores in the host cell membrane. This characterization of YaxAB supports the hypothesis that RovA regulates expression of multiple virulence factors in Y. enterocolitica.
Collapse
|
36
|
Zhang Y, Wang L, Fang N, Qu S, Tan Y, Guo Z, Qiu J, Zhou D, Yang R. Reciprocal regulation of pH 6 antigen gene loci by PhoP and RovA in Yersinia pestis biovar Microtus. Future Microbiol 2013; 8:271-80. [PMID: 23374131 DOI: 10.2217/fmb.12.146] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
AIM To explore the transcriptional regulation of the psaEF and psaABC loci by the RovA and PhoP regulators in Yersinia pestis. MATERIALS & METHODS Primer extension, LacZ fusion, gel mobility shift and DNase I footprinting assays were conducted in combination for this gene regulation study. RESULTS It was determined that PhoP and RovA recognized the promoter-proximal regions of psaEF and psaABC in order to repress and stimulate their transcription, respectively. The translation/transcription start sites, Shine-Dalgarno sequences (ribosomal binding site), core promoter -10 and -35 elements, PhoP and RovA sites and PhoP/RovA consensus-like sequences were identified to determine the structural organization of PhoP/RovA-dependent promoters of psaEF and psaABC. CONCLUSION RovA stimulated psaEF and psaABC, while PhoP repressed these two operons involving the direct association between RovA/PhoP and target promoter regions. The reciprocal regulation of psa genes by PhoP and RovA could contribute to the tightly controlled expression of the pH 6 antigen during infection.
Collapse
Affiliation(s)
- Yiquan Zhang
- State Key Laboratory of Pathogen & Biosecurity, Beijing Institute of Microbiology & Epidemiology, Beijing 100071, China
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Starke M, Richter M, Fuchs TM. The insecticidal toxin genes ofYersinia enterocoliticaare activated by the thermolabile LTTR-like regulator TcaR2 at low temperatures. Mol Microbiol 2013; 89:596-611. [DOI: 10.1111/mmi.12296] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/12/2013] [Indexed: 11/28/2022]
|
38
|
Steinmann R, Dersch P. Thermosensing to adjust bacterial virulence in a fluctuating environment. Future Microbiol 2013; 8:85-105. [PMID: 23252495 DOI: 10.2217/fmb.12.129] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The lifecycle of most microbial pathogens can be divided into two states: existence outside and inside their hosts. The sudden temperature upshift experienced upon entry from environmental or vector reservoirs into a warm-blooded host is one of the most crucial signals informing the pathogens to adjust virulence gene expression and their host-stress survival program. This article reviews the plethora of sophisticated strategies that bacteria have evolved to sense temperature, and outlines the molecular signal transduction mechanisms used to modulate synthesis of crucial virulence determinants. The molecular details of thermal control through conformational changes of DNA, RNA and proteins are summarized, complex and diverse thermosensing principles are introduced and their potential as drug targets or synthetic tools are discussed.
Collapse
Affiliation(s)
- Rebekka Steinmann
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | |
Collapse
|
39
|
Contribution of flagellin subunit FliC to piglet epithelial cells invasion by F18ab E. coli. Vet Microbiol 2013; 166:220-4. [PMID: 23746569 DOI: 10.1016/j.vetmic.2013.04.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/26/2013] [Accepted: 04/28/2013] [Indexed: 11/21/2022]
Abstract
Flagellar structures contribute to the virulence of multiple gastrointestinal pathogens either as the effectors of motility, as adhesins, or as a secretion apparatus for virulence factors. Escherichia coli F18ab variant strains are associated with edema disease (ED) in pig industries worldwide. These strains use flagella to increase the efficiency of epithelial cell invasion. In this study, we aimed to elucidate the mechanism by which flagella contribute to F18ab E. coli invasion. To explore the role of flagella in the invasion process, we performed invasion assays with either flagellated and motile, flagellated but non-motile, or non-flagellated non-motile bacteria. We observed that flagellated but non-motile bacteria invade piglet epithelial cells even more efficiently than the parent wild-type (WT) strain in vitro. By contrast, the non-flagellated bacteria have significantly reduced invasion as compared with the parent strain. These results demonstrate that flagella function mainly as adhesins to enhance the ability of F18ab E. coli to target piglet epithelial cells.
Collapse
|
40
|
Brzóstkowska M, Raczkowska A, Brzostek K. OmpR, a response regulator of the two-component signal transduction pathway, influences inv gene expression in Yersinia enterocolitica O9. Front Cell Infect Microbiol 2012; 2:153. [PMID: 23264953 PMCID: PMC3524506 DOI: 10.3389/fcimb.2012.00153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Accepted: 11/19/2012] [Indexed: 11/13/2022] Open
Abstract
The environmental control of invasin (inv) expression in Yersinia enterocolitica is mediated by a regulatory network composed of negative and positive regulators of inv gene transcription. Previously, we demonstrated that OmpR, a response regulator of the two-component signal transduction pathway EnvZ/OmpR, negatively regulates inv gene expression in Y. enterocolitica O9 by direct interaction with the inv promoter region. This study was undertaken to clarify the role of OmpR in the inv regulatory circuit in which RovA protein has been shown to positively regulate inv transcription. Using ompR, rovA, and ompR rovA Y. enterocolitica mutant backgrounds we showed that the inhibitory effect of OmpR on inv transcription may be observed only when RovA is present/active in Y. enterocolitica cells. To extend our research on inv regulation we examined the effect of OmpR on rovA gene expression. Analysis of rovA-lacZ transcriptional fusion in Y. enterocolitica wild-type and ompR background indicated that OmpR does not influence rovA expression. Thus, our results indicate that OmpR influences inv expression directly via binding to the inv promoter, but not through modulation of rovA expression.
Collapse
Affiliation(s)
- Marta Brzóstkowska
- Department of Applied Microbiology, Institute of Microbiology, Faculty of Biology, University of Warsaw Warsaw, Poland
| | | | | |
Collapse
|
41
|
Heroven AK, Sest M, Pisano F, Scheb-Wetzel M, Steinmann R, Böhme K, Klein J, Münch R, Schomburg D, Dersch P. Crp induces switching of the CsrB and CsrC RNAs in Yersinia pseudotuberculosis and links nutritional status to virulence. Front Cell Infect Microbiol 2012; 2:158. [PMID: 23251905 PMCID: PMC3523269 DOI: 10.3389/fcimb.2012.00158] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 11/27/2012] [Indexed: 12/18/2022] Open
Abstract
Colonization of the intestinal tract and dissemination into deeper tissues by the enteric pathogen Yersinia pseudotuberculosis demands expression of a special set of virulence factors important for the initiation and the persistence of the infection. In this study we demonstrate that many virulence-associated functions are coregulated with the carbohydrate metabolism. This link is mediated by the carbon storage regulator (Csr) system, including the regulatory RNAs CsrB and CsrC, and the cAMP receptor protein (Crp), which both control virulence gene expression in response to the nutrient composition of the medium. Here, we show that Crp regulates the synthesis of both Csr RNAs in an opposite manner. A loss of the crp gene resulted in a strong upregulation of CsrB synthesis, whereas CsrC levels were strongly reduced leading to downregulation of the virulence regulator RovA. Switching of the Csr RNA involves Crp-mediated repression of the response regulator UvrY which activates csrB transcription. To elucidate the regulatory links between virulence and carbon metabolism, we performed comparative metabolome, transcriptome, and phenotypic microarray analyses and found that Crp promotes oxidative catabolism of many different carbon sources, whereas fermentative patterns of metabolism are favored when crp is deleted. Mouse infection experiments further demonstrated that Crp is pivotal for a successful Y. pseudotuberculosis infection. In summary, placement of the Csr system and important virulence factors under control of Crp enables this pathogen to link its nutritional status to virulence in order to optimize biological fitness and infection efficiency through the infectious life cycle.
Collapse
Affiliation(s)
- Ann Kathrin Heroven
- Abteilung Molekulare Infektionsbiologie, Helmholtz-Zentrum für Infektionsforschung Braunschweig, Germany
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Yang R, Du Z, Han Y, Zhou L, Song Y, Zhou D, Cui Y. Omics strategies for revealing Yersinia pestis virulence. Front Cell Infect Microbiol 2012; 2:157. [PMID: 23248778 PMCID: PMC3521224 DOI: 10.3389/fcimb.2012.00157] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2012] [Accepted: 11/27/2012] [Indexed: 01/12/2023] Open
Abstract
Omics has remarkably changed the way we investigate and understand life. Omics differs from traditional hypothesis-driven research because it is a discovery-driven approach. Mass datasets produced from omics-based studies require experts from different fields to reveal the salient features behind these data. In this review, we summarize omics-driven studies to reveal the virulence features of Yersinia pestis through genomics, trascriptomics, proteomics, interactomics, etc. These studies serve as foundations for further hypothesis-driven research and help us gain insight into Y. pestis pathogenesis.
Collapse
Affiliation(s)
- Ruifu Yang
- Beijing Institute of Microbiology and Epidemiology Beijing, China.
| | | | | | | | | | | | | |
Collapse
|
43
|
Schiano CA, Lathem WW. Post-transcriptional regulation of gene expression in Yersinia species. Front Cell Infect Microbiol 2012; 2:129. [PMID: 23162797 PMCID: PMC3493969 DOI: 10.3389/fcimb.2012.00129] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 10/03/2012] [Indexed: 11/13/2022] Open
Abstract
Proper regulation of gene expression is required by bacterial pathogens to respond to continually changing environmental conditions and the host response during the infectious process. While transcriptional regulation is perhaps the most well understood form of controlling gene expression, recent studies have demonstrated the importance of post-transcriptional mechanisms of gene regulation that allow for more refined management of the bacterial response to host conditions. Yersinia species of bacteria are known to use various forms of post-transcriptional regulation for control of many virulence-associated genes. These include regulation by cis- and trans-acting small non-coding RNAs, RNA-binding proteins, RNases, and thermoswitches. The effects of these and other regulatory mechanisms on Yersinia physiology can be profound and have been shown to influence type III secretion, motility, biofilm formation, host cell invasion, intracellular survival and replication, and more. In this review, we discuss these and other post-transcriptional mechanisms and their influence on virulence gene regulation, with a particular emphasis on how these processes influence the virulence of Yersinia in the host.
Collapse
Affiliation(s)
- Chelsea A Schiano
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine Chicago, IL, USA
| | | |
Collapse
|
44
|
A MarR-Type regulator directly activates transcription from the Brucella abortus virB promoter by sharing a redundant role with HutC. J Bacteriol 2012; 194:6431-40. [PMID: 23002224 DOI: 10.1128/jb.01007-12] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Type IV secretion systems (T4SS) are multiprotein structures that direct the translocation of specific molecules across the bacterial cell envelope. As in other bacteria, pathogenicity of the genus Brucella essentially depends on the integrity of the T4SS-encoding virB operon, whose expression is regulated by multiple transcription factors belonging to different families. Previously, we identified IHF and HutC, two direct regulators of the virB genes that were isolated from total protein extracts of Brucella. Here, we report the identification of MdrA, a third regulatory element that was isolated using the same screening procedure. This transcription factor, which belongs to the MarR-family of transcriptional regulators, binds at two different sites of the virB promoter and regulates expression in a growth phase-dependent manner. Like other members of the MarR family, specific ligands were able to dissociate MdrA from DNA in vitro. Determination of the MdrA-binding sites by DNase I footprinting and analyses of protein-DNA complexes by electrophoresis mobility shift assays (EMSAs) showed that MdrA competes with IHF and HutC for the binding to the promoter because their target DNA sequences overlap. Unlike IHF, both MdrA and HutC bound to the promoter without inducing bending of DNA. Moreover, the two latter transcription factors activated virB expression to similar extents, and in doing so, they are functionally redundant. Taken together, our results show that MdrA is a regulatory element that directly modulates the activity of the virB promoter and is probably involved in coordinating gene expression in response to specific environmental signals.
Collapse
|
45
|
Concerted actions of a thermo-labile regulator and a unique intergenic RNA thermosensor control Yersinia virulence. PLoS Pathog 2012; 8:e1002518. [PMID: 22359501 PMCID: PMC3280987 DOI: 10.1371/journal.ppat.1002518] [Citation(s) in RCA: 116] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Accepted: 12/19/2011] [Indexed: 11/19/2022] Open
Abstract
Expression of all Yersinia pathogenicity factors encoded on the virulence plasmid, including the yop effector and the ysc type III secretion genes, is controlled by the transcriptional activator LcrF in response to temperature. Here, we show that a protein- and RNA-dependent hierarchy of thermosensors induce LcrF synthesis at body temperature. Thermally regulated transcription of lcrF is modest and mediated by the thermo-sensitive modulator YmoA, which represses transcription from a single promoter located far upstream of the yscW-lcrF operon at moderate temperatures. The transcriptional response is complemented by a second layer of temperature-control induced by a unique cis-acting RNA element located within the intergenic region of the yscW-lcrF transcript. Structure probing demonstrated that this region forms a secondary structure composed of two stemloops at 25°C. The second hairpin sequesters the lcrF ribosomal binding site by a stretch of four uracils. Opening of this structure was favored at 37°C and permitted ribosome binding at host body temperature. Our study further provides experimental evidence for the biological relevance of an RNA thermometer in an animal model. Following oral infections in mice, we found that two different Y. pseudotuberculosis patient isolates expressing a stabilized thermometer variant were strongly reduced in their ability to disseminate into the Peyer's patches, liver and spleen and have fully lost their lethality. Intriguingly, Yersinia strains with a destabilized version of the thermosensor were attenuated or exhibited a similar, but not a higher mortality. This illustrates that the RNA thermometer is the decisive control element providing just the appropriate amounts of LcrF protein for optimal infection efficiency.
Collapse
|
46
|
Uliczka F, Dersch P. Unique virulence properties of Yersinia enterocolitica O:3. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 954:281-7. [PMID: 22782774 DOI: 10.1007/978-1-4614-3561-7_35] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Frank Uliczka
- Department of Molecular Infection Biology, Helmholtz Center for Infection Research, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | | |
Collapse
|
47
|
Regulation of virulence gene expression by regulatory RNA elements in Yersinia pseudotuberculosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 954:315-23. [PMID: 22782778 DOI: 10.1007/978-1-4614-3561-7_39] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
|
48
|
OmpR, a Central Integrator of Several Cellular Responses in Yersinia enterocolitica. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 954:325-34. [DOI: 10.1007/978-1-4614-3561-7_40] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
49
|
In vivo-induced InvA-like autotransporters Ifp and InvC of Yersinia pseudotuberculosis promote interactions with intestinal epithelial cells and contribute to virulence. Infect Immun 2011; 80:1050-64. [PMID: 22158741 DOI: 10.1128/iai.05715-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The Yersinia pseudotuberculosis Ifp and InvC molecules are putative autotransporter proteins with a high homology to the invasin (InvA) protein. To characterize the function of these surface proteins, we expressed both factors in Escherichia coli K-12 and demonstrated the attachment of Ifp- and InvC-expressing bacteria to human-, mouse-, and pig-derived intestinal epithelial cells. Ifp also was found to mediate microcolony formation and internalization into polarized human enterocytes. The ifp and invC genes were not expressed under in vitro conditions but were found to be induced in the Peyer's patches of the mouse intestinal tract. In a murine coinfection model, the colonization of the Peyer's patches and the mesenteric lymph nodes of mice by the ifp-deficient strain was significantly reduced, and considerably fewer bacteria reached liver and spleen. The absence of InvC did not have a severe influence on bacterial colonization in the murine infection model, and it resulted in only a slightly reduced number of invC mutants in the Peyer's patches. The analysis of the host immune response demonstrated that the presence of Ifp and InvC reduced the recruitment of professional phagocytes, especially neutrophils, in the Peyer's patches. These findings support a role for the adhesins in modulating host-pathogen interactions that are important for immune defense.
Collapse
|
50
|
Zhang Y, Gao H, Wang L, Xiao X, Tan Y, Guo Z, Zhou D, Yang R. Molecular characterization of transcriptional regulation of rovA by PhoP and RovA in Yersinia pestis. PLoS One 2011; 6:e25484. [PMID: 21966533 PMCID: PMC3180457 DOI: 10.1371/journal.pone.0025484] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 09/06/2011] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Yersinia pestis is the causative agent of plague. The two transcriptional regulators, PhoP and RovA, are required for the virulence of Y. pestis through the regulation of various virulence-associated loci. They are the global regulators controlling two distinct large complexes of cellular pathways. METHODOLOGY/PRINCIPAL FINDINGS Based on the LacZ fusion, primer extension, gel mobility shift, and DNase I footprinting assays, RovA is shown to recognize both of the two promoters of its gene in Y. pestis. The autoregulation of RovA appears to be a conserved mechanism shared by Y. pestis and its closely related progenitor, Y. pseudotuberculosis. In Y. pestis, the PhoP regulator responds to low magnesium signals and then negatively controls only one of the two promoters of rovA through PhoP-promoter DNA association. CONCLUSIONS/SIGNIFICANCE RovA is a direct transcriptional activator for its own gene in Y. pestis, while PhoP recognizes the promoter region of rovA to repress its transcription. The direct regulatory association between PhoP and RovA bridges the PhoP and RovA regulons in Y. pestis.
Collapse
Affiliation(s)
- Yiquan Zhang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - He Gao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
- State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing, People’s Republic of China
| | - Li Wang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Xiao Xiao
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Yafang Tan
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Zhaobiao Guo
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
| | - Dongsheng Zhou
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
- * E-mail: (DZ); (RY)
| | - Ruifu Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, People’s Republic of China
- * E-mail: (DZ); (RY)
| |
Collapse
|