301
|
Mole BM, Baltrus DA, Dangl JL, Grant SR. Global virulence regulation networks in phytopathogenic bacteria. Trends Microbiol 2007; 15:363-71. [PMID: 17627825 DOI: 10.1016/j.tim.2007.06.005] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 05/04/2007] [Accepted: 06/22/2007] [Indexed: 11/28/2022]
Abstract
Phytopathogens coordinate multifaceted life histories and deploy stratified virulence determinants via complex, global regulation networks. We dissect the global regulation of four distantly related model phytopathogens to evaluate large-scale events and mechanisms that determine successful pathogenesis. Overarching themes include dependence on centralized cell-to-cell communication systems, pervasive two-component signal-transduction systems, post-transcriptional regulation systems, AraC-like regulators and sigma factors. Although these common regulatory systems control virulence, each functions in different capacities, and to differing ends, in the diverse species. Hence, the virulence regulation network of each species determines its survival and success in various life histories and niches.
Collapse
Affiliation(s)
- Beth M Mole
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | | | |
Collapse
|
302
|
García-Calderón CB, Casadesús J, Ramos-Morales F. Rcs and PhoPQ regulatory overlap in the control of Salmonella enterica virulence. J Bacteriol 2007; 189:6635-44. [PMID: 17616593 PMCID: PMC2045174 DOI: 10.1128/jb.00640-07] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Genetic screens based on the use of MudJ-generated lac fusions permitted the identification of novel genes regulated by the Rcs signal transduction system in Salmonella enterica serovar Typhimurium. Besides genes that are also found in the Escherichia coli genome, our screens identified Salmonella-specific genes regulated by RcsB, including bapA, siiE, srfA, and srfB. Here we show that the srfABC operon is negatively regulated by RcsB and by PhoP. In vivo studies using mutants with constitutive activation of the Rcs and/or PhoPQ system suggested that there is an overlap between these regulatory systems in the control of Salmonella virulence.
Collapse
Affiliation(s)
- Clara B García-Calderón
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avda Reina Mercedes, 6, 41012 Sevilla, Spain
| | | | | |
Collapse
|
303
|
Audic S, Robert C, Campagna B, Parinello H, Claverie JM, Raoult D, Drancourt M. Genome analysis of Minibacterium massiliensis highlights the convergent evolution of water-living bacteria. PLoS Genet 2007; 3:e138. [PMID: 17722982 PMCID: PMC1950954 DOI: 10.1371/journal.pgen.0030138] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2007] [Accepted: 07/03/2007] [Indexed: 12/25/2022] Open
Abstract
Filtration usually eliminates water-living bacteria. Here, we report on the complete genome sequence of Minibacterium massiliensis, a beta-proteobacteria that was recovered from 0.22-mum filtered water used for patients in the hospital. The unexpectedly large 4,110,251-nucleotide genome sequence of M. massiliensis was determined using the traditional shotgun sequencing approach. Bioinformatic analyses shows that the M. massiliensis genome sequence illustrates characteristic features of water-living bacteria, including overrepresentation of genes encoding transporters and transcription regulators. Phylogenomic analysis based on the gene content of available bacterial genome sequences displays a congruent evolution of water-living bacteria from various taxonomic origins, principally for genes involved in energy production and conversion, cell division, chromosome partitioning, and lipid metabolism. This phylogenomic clustering partially results from lateral gene transfer, which appears to be more frequent in water than in other environments. The M. massiliensis genome analyses strongly suggest that water-living bacteria are a common source for genes involved in heavy-metal resistance, antibiotics resistance, and virulence factors.
Collapse
Affiliation(s)
- Stéphane Audic
- Structural and Genomic Information Laboratory, Institute for Structural Biology and Microbiology, Marseille, France
- CNRS, UPR2589, Marseille, France
- * To whom correspondence should be addressed. E-mail: (SA); (MD)
| | - Catherine Robert
- Unité des Rickettsies, Faculté de Médecine, Université de la Méditerranée, Marseille, France
- CNRS, UMR6020, Marseille, France
| | - Bernard Campagna
- Unité des Rickettsies, Faculté de Médecine, Université de la Méditerranée, Marseille, France
- CNRS, UMR6020, Marseille, France
| | - Hugues Parinello
- Unité des Rickettsies, Faculté de Médecine, Université de la Méditerranée, Marseille, France
- CNRS, UMR6020, Marseille, France
| | - Jean-Michel Claverie
- Structural and Genomic Information Laboratory, Institute for Structural Biology and Microbiology, Marseille, France
- CNRS, UPR2589, Marseille, France
| | - Didier Raoult
- Unité des Rickettsies, Faculté de Médecine, Université de la Méditerranée, Marseille, France
- CNRS, UMR6020, Marseille, France
| | - Michel Drancourt
- Unité des Rickettsies, Faculté de Médecine, Université de la Méditerranée, Marseille, France
- CNRS, UMR6020, Marseille, France
- * To whom correspondence should be addressed. E-mail: (SA); (MD)
| |
Collapse
|
304
|
Gryllos I, Grifantini R, Colaprico A, Jiang S, Deforce E, Hakansson A, Telford JL, Grandi G, Wessels MR. Mg(2+) signalling defines the group A streptococcal CsrRS (CovRS) regulon. Mol Microbiol 2007; 65:671-83. [PMID: 17608796 DOI: 10.1111/j.1365-2958.2007.05818.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
CsrRS (or CovRS) is a two-component system implicated in the control of multiple virulence determinants in the important human pathogen, group A Streptococcus (GAS). Earlier studies suggested that extracellular Mg(2+) signalled through the presumed sensor histidine kinase, CsrS. We now confirm those findings, as complementation of a csrS mutant restored Mg(2+)-dependent gene regulation. Moreover, we present strong evidence that Mg(2+) signals through CsrS to regulate an extensive and previously undefined repertoire of GAS genes. The effect of Mg(2+) on regulation of global gene expression was evaluated using genomic microarrays in an M-type 3 strain of GAS and in an isogenic csrS mutant. Unexpectedly, of the 72 genes identified in the Mg(2+)-stimulated CsrRS regulon, 42 were absent from the CsrR regulon (the latter being defined by comparison of wild-type and CsrR mutant transcriptomes at low Mg(2+)). We observed CsrS-dependent regulation of 72 of the 73 genes whose expression changed in response to elevated extracellular Mg(2+) in wild-type bacteria, a result that identifies CsrS as the principal, if not exclusive, sensor for extracellular Mg(2+) in GAS. To our knowledge, this study is the first to characterize global gene regulation by a GAS two-component system in response to a specific environmental stimulus.
Collapse
Affiliation(s)
- Ioannis Gryllos
- Division of Infectious Diseases, Children's Hospital Boston, Harvard Medical School, Boston, MA 02115, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
305
|
Prosseda G, Carmela Latella M, Barbagallo M, Nicoletti M, Al Kassas R, Casalino M, Colonna B. The two-faced role of cad genes in the virulence of pathogenic Escherichia coli. Res Microbiol 2007; 158:487-93. [PMID: 17656072 DOI: 10.1016/j.resmic.2007.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 04/29/2007] [Accepted: 05/02/2007] [Indexed: 11/18/2022]
Abstract
In enterobacteria, acid stress induces expression of the cad system which is involved in maintaining intracellular pH at levels compatible with cell survival. Despite its crucial role, the cad operon is silenced in Shigella and in other pathogenic Escherichia coli. In the present review, we will address the question of why and how the cad locus has been sacrificed for the sake of optimal expression of virulence traits.
Collapse
Affiliation(s)
- Gianni Prosseda
- Istituto Pasteur-Fondazione Cenci Bolognetti, Dip. Biologia Cellulare e dello Sviluppo, Sapienza-Università di Roma, Via dei Sardi 70, 00185 Rome, Italy
| | | | | | | | | | | | | |
Collapse
|
306
|
Hussa EA, O'Shea TM, Darnell CL, Ruby EG, Visick KL. Two-component response regulators of Vibrio fischeri: identification, mutagenesis, and characterization. J Bacteriol 2007; 189:5825-38. [PMID: 17586650 PMCID: PMC1952042 DOI: 10.1128/jb.00242-07] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Two-component signal transduction systems are utilized by prokaryotic and eukaryotic cells to sense and respond to environmental stimuli, both to maintain homeostasis and to rapidly adapt to changing conditions. Studies have begun to emerge that utilize a large-scale mutagenesis approach to analyzing these systems in prokaryotic organisms. Due to the recent availability of its genome sequence, such a global approach is now possible for the marine bioluminescent bacterium Vibrio fischeri, which exists either in a free-living state or as a mutualistic symbiont within a host organism such as the Hawaiian squid species Euprymna scolopes. In this work, we identified 40 putative two-component response regulators encoded within the V. fischeri genome. Based on the type of effector domain present, we classified six as NarL type, 13 as OmpR type, and six as NtrC type; the remaining 15 lacked a predicted DNA-binding domain. We subsequently mutated 35 of these genes via a vector integration approach and analyzed the resulting mutants for roles in bioluminescence, motility, and competitive colonization of squid. Through these assays, we identified three novel regulators of V. fischeri luminescence and seven regulators that altered motility. Furthermore, we found 11 regulators with a previously undescribed effect on competitive colonization of the host squid. Interestingly, five of the newly characterized regulators each affected two or more of the phenotypes examined, strongly suggesting interconnectivity among systems. This work represents the first large-scale mutagenesis of a class of genes in V. fischeri using a genomic approach and emphasizes the importance of two-component signal transduction in bacterium-host interactions.
Collapse
Affiliation(s)
- Elizabeth A Hussa
- Department of Microbiology and Immunology, Loyola University Chicago, 2160 S. First Avenue, Maywood, IL 60153, USA
| | | | | | | | | |
Collapse
|
307
|
Verhamme DT, Kiley TB, Stanley-Wall NR. DegU co-ordinates multicellular behaviour exhibited by Bacillus subtilis. Mol Microbiol 2007; 65:554-68. [PMID: 17590234 DOI: 10.1111/j.1365-2958.2007.05810.x] [Citation(s) in RCA: 161] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Unicellular organisms use a variety of mechanisms to co-ordinate activity within a community and accomplish complex multicellular processes. Because some of the processes that are exhibited by one species can be physiologically incompatible, it raises the question of how entry into these different pathways is regulated. In the Gram-positive bacterium Bacillus subtilis, genetic competence, swarming motility, biofilm formation, complex colony architecture and protease production are all regulated by the response regulator DegU. DegU appears to integrate environmental signals and co-ordinate multicellular behaviours that are subsequently manifested at different levels of DegU phosphorylation. Data are presented which indicate that: (i) swarming motility is activated by very low levels of DegU approximately P that can be generated independently from its cognate sensor kinase DegS; (ii) complex colony architecture is activated by low levels of DegU approximately P that are produced in a DegS-dependent manner to activate transcription of yvcA, a novel gene required for complex colony architecture; and (iii) high levels of DegU approximately P inhibit complex colony architecture and swarming motility but are required prior to the activation of exoprotease production. A model is proposed to explain why such a system may have evolved within B. subtilis to control these multicellular processes through a single regulator.
Collapse
Affiliation(s)
- Daniël T Verhamme
- Division of Environmental and Applied Biology, College of Life Sciences, MSI/WTB/JBC Complex, University of Dundee, Dundee DD1 4EH, UK
| | | | | |
Collapse
|
308
|
Carlsson KE, Liu J, Edqvist PJ, Francis MS. Extracytoplasmic-stress-responsive pathways modulate type III secretion in Yersinia pseudotuberculosis. Infect Immun 2007; 75:3913-24. [PMID: 17517869 PMCID: PMC1951977 DOI: 10.1128/iai.01346-06] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Three signal transduction pathways, the two-component systems CpxRA and BaeSR and the alternative sigma factor sigma(E), respond to extracytoplasmic stress that facilitates bacterial adaptation to changing environments. At least the CpxRA and sigma(E) pathways control the production of protein-folding and degradation factors that counter the effects of protein misfolding in the periplasm. This function also influences the biogenesis of multicomponent extracellular appendages that span the bacterial envelope, such as various forms of pili. Herein, we investigated whether any of these regulatory pathways in the enteropathogen Yersinia pseudotuberculosis affect the functionality of the Ysc-Yop type III secretion system. This is a multicomponent molecular syringe spanning the bacterial envelope used to inject effector proteins directly into eukaryotic cells. Disruption of individual components revealed that the Cpx and sigma(E) pathways are important for Y. pseudotuberculosis type III secretion of Yops (Yersinia outer proteins). In particular, a loss of CpxA, a sensor kinase, reduced levels of structural Ysc (Yersinia secretion) components in bacterial membranes, suggesting that these mutant bacteria are less able to assemble a functional secretion apparatus. Moreover, these bacteria were no longer capable of localizing Yops into the eukaryotic cell interior. In addition, a cpxA lcrQ double mutant engineered to overproduce and secrete Yops was still impaired in intoxicating cells. Thus, the Cpx pathway might mediate multiple influences on bacterium-target cell contact that modulate Yersinia type III secretion-dependent host cell cytotoxicity.
Collapse
Affiliation(s)
- Katrin E Carlsson
- Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
| | | | | | | |
Collapse
|
309
|
Friedland N, Mack TR, Yu M, Hung LW, Terwilliger TC, Waldo GS, Stock AM. Domain orientation in the inactive response regulator Mycobacterium tuberculosis MtrA provides a barrier to activation. Biochemistry 2007; 46:6733-43. [PMID: 17511470 PMCID: PMC2528954 DOI: 10.1021/bi602546q] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The structure of MtrA, an essential gene product for the human pathogen Mycobacterium tuberculosis, has been solved to a resolution of 2.1 A. MtrA is a member of the OmpR/PhoB family of response regulators and represents the fourth family member for which a structure of the protein in its inactive state has been determined. As is true for all OmpR/PhoB family members, MtrA possesses an N-terminal regulatory domain and a C-terminal winged helix-turn-helix DNA-binding domain, with phosphorylation of the regulatory domain modulating the activity of the protein. In the inactive form of MtrA, these two domains form an extensive interface that is composed of the alpha4-beta5-alpha5 face of the regulatory domain and the C-terminal end of the positioning helix, the trans-activation loop, and the recognition helix of the DNA-binding domain. This domain orientation suggests a mechanism of mutual inhibition by the two domains. Activation of MtrA would require a disruption of this interface to allow the alpha4-beta5-alpha5 face of the regulatory domain to form the intermolecule interactions that are associated with the active state and to allow the recognition helix to interact with DNA. Furthermore, the interface appears to stabilize the inactive conformation of MtrA, potentially reducing the rate of phosphorylation of the N-terminal domain. This combination of effects may form a switch, regulating the activity of MtrA. The domain orientation exhibited by MtrA also provides a rationale for the variation in linker length that is observed within the OmpR/PhoB family of response regulators.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Ann M. Stock
- To whom correspondence should be addressed at Center for Advanced Biotechnology and Medicine, 679 Hoes Lane, Piscataway, NJ 08854. Telephone: (732) 235−4844. Fax (732) 235−5289. E-mail:
| |
Collapse
|
310
|
Mohapatra NP, Soni S, Bell BL, Warren R, Ernst RK, Muszynski A, Carlson RW, Gunn JS. Identification of an orphan response regulator required for the virulence of Francisella spp. and transcription of pathogenicity island genes. Infect Immun 2007; 75:3305-14. [PMID: 17452468 PMCID: PMC1932945 DOI: 10.1128/iai.00351-07] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Francisella tularensis is a category A agent of biowarfare/biodefense. Little is known about the regulation of virulence gene expression in Francisella spp. Comparatively few regulatory factors exist in Francisella, including those belonging to two-component systems (TCS). However, orphan members of typical TCS can be identified. To determine if orphan TCS members affect Francisella gene expression, a gene encoding a product with high similarity to the Salmonella PmrA response regulator (FTT1557c/FNU0663.2) was deleted in Francisella novicida (a model organism for F. tularensis). The F. novicida pmrA mutant was defective in survival/growth within human and murine macrophage cell lines and was 100% defective in virulence in mice at a dose of up to 10(8) CFU. In addition, the mutant strain demonstrated increased susceptibility to antimicrobial peptide killing, but no differences were observed between the lipid A of the mutant and the parental strain, as has been observed with pmrA mutants of other microbes. The F. novicida pmrA mutant was 100% protective as a single-dose vaccine when challenge was with 10(6) CFU of F. novicida but did not protect against type A Schu S4 wild-type challenge. DNA microarray analysis identified 65 genes regulated by PmrA. The majority of these genes were located in the region surrounding pmrA or within the Francisella pathogenicity island (FPI). These FPI genes are also regulated by MglA, but MglA does not regulate pmrA, nor does PmrA regulate MglA. Thus, the orphan response regulator PmrA is an important factor in controlling virulence in F. novicida, and a pmrA mutant strain is an effective vaccine against homologous challenge.
Collapse
Affiliation(s)
- Nrusingh P Mohapatra
- Center for Microbial Interface Biology, Department of Molecular Biology, Immunology and Medical Genetics, The Ohio State University, 460 W. 12th Avenue, Columbus, OH 43210-1214, USA
| | | | | | | | | | | | | | | |
Collapse
|
311
|
Gao R, Mack TR, Stock AM. Bacterial response regulators: versatile regulatory strategies from common domains. Trends Biochem Sci 2007; 32:225-34. [PMID: 17433693 PMCID: PMC3655528 DOI: 10.1016/j.tibs.2007.03.002] [Citation(s) in RCA: 243] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2006] [Revised: 02/07/2007] [Accepted: 03/15/2007] [Indexed: 01/29/2023]
Abstract
Response regulators (RRs) comprise a major family of signaling proteins in prokaryotes. A modular architecture that consists of a conserved receiver domain and a variable effector domain enables RRs to function as phosphorylation-regulated switches that couple a wide variety of cellular behaviors to environmental cues. Recently, advances have been made in understanding RR functions both at genome-wide and molecular levels. Global techniques have been developed to analyze RR input and output, expanding the scope of characterization of these versatile components. Meanwhile, structural studies have revealed that, despite common structures and mechanisms of function within individual domains, a range of interactions between receiver and effector domains confer great diversity in regulatory strategies, optimizing individual RRs for the specific regulatory needs of different signaling systems.
Collapse
Affiliation(s)
- Rong Gao
- Center for Advanced Biotechnology and Medicine, Howard Hughes Medical Institute, Piscataway, NJ 08854, USA
| | | | | |
Collapse
|
312
|
Chen C, Tang J, Dong W, Wang C, Feng Y, Wang J, Zheng F, Pan X, Liu D, Li M, Song Y, Zhu X, Sun H, Feng T, Guo Z, Ju A, Ge J, Dong Y, Sun W, Jiang Y, Wang J, Yan J, Yang H, Wang X, Gao GF, Yang R, Wang J, Yu J. A glimpse of streptococcal toxic shock syndrome from comparative genomics of S. suis 2 Chinese isolates. PLoS One 2007; 2:e315. [PMID: 17375201 PMCID: PMC1820848 DOI: 10.1371/journal.pone.0000315] [Citation(s) in RCA: 210] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 02/19/2007] [Indexed: 12/31/2022] Open
Abstract
Background Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen, causing more than 200 cases of severe human infection worldwide, with the hallmarks of meningitis, septicemia, arthritis, etc. Very recently, SS2 has been recognized as an etiological agent for streptococcal toxic shock syndrome (STSS), which was originally associated with Streptococcus pyogenes (GAS) in Streptococci. However, the molecular mechanisms underlying STSS are poorly understood. Methods and Findings To elucidate the genetic determinants of STSS caused by SS2, whole genome sequencing of 3 different Chinese SS2 strains was undertaken. Comparative genomics accompanied by several lines of experiments, including experimental animal infection, PCR assay, and expression analysis, were utilized to further dissect a candidate pathogenicity island (PAI). Here we show, for the first time, a novel molecular insight into Chinese isolates of highly invasive SS2, which caused two large-scale human STSS outbreaks in China. A candidate PAI of ∼89 kb in length, which is designated 89K and specific for Chinese SS2 virulent isolates, was investigated at the genomic level. It shares the universal properties of PAIs such as distinct GC content, consistent with its pivotal role in STSS and high virulence. Conclusions To our knowledge, this is the first PAI candidate from S. suis worldwide. Our finding thus sheds light on STSS triggered by SS2 at the genomic level, facilitates further understanding of its pathogenesis and points to directions of development on some effective strategies to combat highly pathogenic SS2 infections.
Collapse
Affiliation(s)
- Chen Chen
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Jiaqi Tang
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
- * To whom correspondence should be addressed. E-mail: (JT); (XW); (GG); (RY); (JW); (JY)
| | - Wei Dong
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Changjun Wang
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Youjun Feng
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
- China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- Graduate University, Chinese Academy of Sciences, Beijing, China
| | - Jing Wang
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Feng Zheng
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Xiuzhen Pan
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Di Liu
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
- China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ming Li
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Yajun Song
- Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Xinxing Zhu
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Haibo Sun
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Tao Feng
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Zhaobiao Guo
- Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Aiping Ju
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Junchao Ge
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Yaqing Dong
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Wen Sun
- Department of Epidemiology, Research Institute for Medicine of Nanjing Command, Nanjing, China
| | - Yongqiang Jiang
- Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
| | - Jun Wang
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
- The Institute of Human Genetics, University of Aarhus, Aarhus, Denmark
| | - Jinghua Yan
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
- China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Huanming Yang
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
| | - Xiaoning Wang
- School of Biosciences and Bioengineering, South China University of Technology, Guangzhou, China
- * To whom correspondence should be addressed. E-mail: (JT); (XW); (GG); (RY); (JW); (JY)
| | - George F. Gao
- Center for Molecular Immunology, Institute of Microbiology, Chinese Academy of Science, Beijing, China
- China-Japan Joint Laboratory of Molecular Immunology and Molecular Microbiology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- * To whom correspondence should be addressed. E-mail: (JT); (XW); (GG); (RY); (JW); (JY)
| | - Ruifu Yang
- Institute of Microbiology and Epidemiology, Academy of Military Medical Sciences, Beijing, China
- * To whom correspondence should be addressed. E-mail: (JT); (XW); (GG); (RY); (JW); (JY)
| | - Jian Wang
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
- * To whom correspondence should be addressed. E-mail: (JT); (XW); (GG); (RY); (JW); (JY)
| | - Jun Yu
- Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, China
- James D. Watson Institute of Genome Sciences of Zhejiang University, Hangzhou, China
- * To whom correspondence should be addressed. E-mail: (JT); (XW); (GG); (RY); (JW); (JY)
| |
Collapse
|
313
|
Abstract
Phagosomes are fascinating subcellular structures. After all, there are only a few compartments that are born before our very eyes and whose development we can follow in a light microscope until their contents disintegrate and are completely absorbed. Yet, some phagosomes are taken advantage of by pathogenic microorganisms, which change their fate. Research into phagosome biogenesis has flourished in recent years - the purpose of this review is to give a glimpse of where this research stands, with emphasis on the cell biology of macrophage phagosomes, on new model organisms for the study of phagosome biogenesis and on intracellular pathogens and their interference with normal phagosome function.
Collapse
Affiliation(s)
- Albert Haas
- Cell Biology Institute, University of Bonn, Ulrich-Haberland-Str. 61a, 53121 Bonn, Germany.
| |
Collapse
|
314
|
Braun Y, Smirnova AV, Weingart H, Schenk A, Ullrich MS. A Temperature‐Sensing Histidine Kinase—Function, Genetics, and Membrane Topology. Methods Enzymol 2007; 423:222-49. [PMID: 17609134 DOI: 10.1016/s0076-6879(07)23010-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Two-component systems provide a means for bacteria to sense and adapt to environmental signals in order to survive in a continuously changing environment. Understanding of the mechanism by which these systems function is important in combating bacterial infections because many bacterial two-component systems are associated with virulence. The plant pathogenic bacterium Pseudomonas syringae pv. glycinea PG4180 synthesizes high levels of the phytotoxin coronatine at the virulence-promoting temperature of 18 degrees , but not at 28 degrees , the optimal growth temperature. Temperature-dependent coronatine biosynthesis is regulated by a modified two-component system, consisting of the response regulator, CorR, the histidine protein kinase CorS, and a third component, CorP. To elucidate the mechanism by which CorRSP functions, genetic, transcriptional, and biochemical analyses were applied, including in vitro and in planta reporter gene analysis, mRNA quantification, protein expression, mutagenesis, and membrane topology analysis. A combination of these techniques helped to elucidate, to a considerable extent, the temperature-sensing activity of CorS, which seems to act as a membrane-bound molecular thermometer.
Collapse
Affiliation(s)
- Yvonne Braun
- School of Engineering and Science, International University Bremen, Bremen, Germany
| | | | | | | | | |
Collapse
|
315
|
Williams CL, Cotter PA. Autoregulation is essential for precise temporal and steady-state regulation by the Bordetella BvgAS phosphorelay. J Bacteriol 2006; 189:1974-82. [PMID: 17158656 PMCID: PMC1855725 DOI: 10.1128/jb.01684-06] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Bordetella BvgAS virulence control system is prototypical of phosphorelays that use a polydomain sensor and a response regulator to control gene expression in response to environmental cues. BvgAS controls the expression of at least three distinct phenotypic phases (Bvg(-), Bvg(i), and Bvg(+)) by differentially regulating the expression of at least four classes of genes. Among the loci regulated by BvgAS is bvgAS itself. We investigated the role of autoregulation in the ability of BvgAS to control multiple gene expression patterns in a temporal and steady-state manner by constructing Bordetella bronchiseptica strains in which the bvgAS promoter was replaced with constitutively active promoters. Our results show that positive autoregulation of bvgAS transcription is required for the temporal expression of multiple phenotypic phases that occurs in response to a shift from Bvg(-)-phase conditions to Bvg(+)-phase conditions. Autoregulation was also shown to contribute to steady-state regulation; it influences the sensitivity of the system in response to subtle differences in signal intensity. In addition, considered in relation to BvgA and BvgS activities demonstrated in vitro, our results provide insight into how BvgA and BvgS function mechanistically.
Collapse
Affiliation(s)
- Corinne L Williams
- Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Barbara, CA 93106-9610, USA
| | | |
Collapse
|
316
|
Homerova D, Surdova K, Mikusova K, Kormanec J. Identification of promoters recognized by RNA polymerase containing Mycobacterium tuberculosis stress-response sigma factor sigma(F). Arch Microbiol 2006; 187:185-97. [PMID: 17089148 DOI: 10.1007/s00203-006-0185-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 09/20/2006] [Accepted: 10/09/2006] [Indexed: 11/24/2022]
Abstract
A previously optimized Escherichia coli two-plasmid system was used to identify Mycobacterium tuberculosis promoters recognized by RNA polymerase containing the M. tuberculosis stress response sigma factor sigma(F). The method allowed the identification of five new sigma(F)-dependent promoters. Transcriptional start points of the promoters were determined by high-resolution S1-nuclease mapping using RNA prepared from E. coli containing the two-plasmid system. The promoters were confirmed by an in vitro transcription assay. The Mycobacterium smegmatis and Mycobacterium tuberculosis core RNA polymerases, after complementation with sigma(F), were able to recognize all the five promoters. All the promoters contained sequences highly similar to the sequence of the previously identified M. tuberculosis sigma(F)-dependent promoter, usfXp1. Comparison of the promoters revealed a sigma(F) consensus sequence GtTtga-N(14-18)-GGGTAT. The sigma(F)-dependent promoters may govern expression of genes encoding a transcription regulator homologous to the response regulators of bacterial two-component signal transduction systems and proteins with unknown function.
Collapse
Affiliation(s)
- Dagmar Homerova
- Institute of Molecular Biology, Center of Excellence for Molecular Medicine, Slovak Academy of Sciences, Dubravska cesta 21, 845 51, Bratislava, Slovak Republic
| | | | | | | |
Collapse
|
317
|
Rajagopal L, Vo A, Silvestroni A, Rubens CE. Regulation of cytotoxin expression by converging eukaryotic-type and two-component signalling mechanisms in Streptococcus agalactiae. Mol Microbiol 2006; 62:941-57. [PMID: 17005013 PMCID: PMC2593684 DOI: 10.1111/j.1365-2958.2006.05431.x] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Signal transducing mechanisms are essential for regulation of gene expression in both prokaryotic and eukaryotic organisms. Regulation of gene expression in eukaryotes is accomplished by serine/threonine and tyrosine kinases and cognate phosphatases. In contrast, gene expression in prokaryotes is controlled by two-component systems that comprise a sensor histidine kinase and a cognate DNA binding response regulator. Pathogenic bacteria utilize two-component systems to regulate expression of their virulence factors and for adaptive responses to the external environment. We have previously shown that the human pathogen Streptococcus agalactiae (Group B Streptococci, GBS) encodes a single eukaryotic-type serine/threonine kinase Stk1, which is important for virulence of the organism. In this study, we aimed to understand how Stk1 contributes to virulence of GBS. Our results indicate that Stk1 expression is important for resistance of GBS to human blood, neutrophils and oxidative stress. Consistent with these observations, Stk1 positively regulates transcription of a cytotoxin, beta-haemolysin/cytolysin (beta-H/C) that is critical for survival of GBS in the bloodstream and for resistance to oxidative stress. Interestingly, positive regulation of beta-H/C by Stk1 requires the two-component regulator CovR. Further, we show that Stk1 can negatively regulate transcription of CAMP factor in a CovR-dependent manner. As Stk1 phosphorylates CovR in vitro, these data suggest that serine/threonine phosphorylation impacts CovR-mediated regulation of GBS gene expression. In summary, our studies provide novel information that a eukaryotic-type serine/threonine kinase regulates two-component-mediated expression of GBS cytotoxins.
Collapse
Affiliation(s)
- Lakshmi Rajagopal
- Division of Infectious Diseases and Department of Pediatrics, Children's Hospital and Regional Medical Center and University of Washington, Suite 300, 307 Westlake Avenue North, Seattle, WA 98109, USA.
| | | | | | | |
Collapse
|
318
|
Bekker M, Teixeira De Mattos MJ, Hellingwerf KJ. The role of two-component regulation systems in the physiology of the bacterial cell. Sci Prog 2006; 89:213-42. [PMID: 17338439 PMCID: PMC10368358 DOI: 10.3184/003685006783238308] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two-component regulation systems (TCRSs) are the dominant type of signal transduction system in prokaryotes that are used to inform the cellular trancriptional machinery (and additional targets for regulation, like the motility apparatus) about actual changes in the extracellular physicochemical conditions. We now review their molecular structure and enzymatic characteristics, their mutual interactions and its implications, and their role in cellular physiology. Specific emphasis is placed on the ArcB/A system, a representative of the phosphorelay type of TCRS, and a key player in the adjustment of the cellular make-up of enterobacteria in response to alterations in the oxygen availability. Also some applied aspects of the TCRSs are discussed, i.e. their role as a target to develop new anti-bacterials and their application in biotechnology (or: 'synthetic biology').
Collapse
Affiliation(s)
| | | | - Klaas J. Hellingwerf
- Laboratory for Microbiology, Swammerdam Institute for Life Sciences, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands
| |
Collapse
|