1
|
Zhao Z, Hu Y, Hu Y, White AP, Wang Y. Features and algorithms: facilitating investigation of secreted effectors in Gram-negative bacteria. Trends Microbiol 2023; 31:1162-1178. [PMID: 37349207 DOI: 10.1016/j.tim.2023.05.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/22/2023] [Accepted: 05/22/2023] [Indexed: 06/24/2023]
Abstract
Gram-negative bacteria deliver effector proteins through type III, IV, or VI secretion systems (T3SSs, T4SSs, and T6SSs) into host cells, causing infections and diseases. In general, effector proteins for each of these distinct secretion systems lack homology and are difficult to identify. Sequence analysis has disclosed many common features, helping us to understand the evolution, function, and secretion mechanisms of the effectors. In combination with various algorithms, the known common features have facilitated accurate prediction of new effectors. Ensemblers or integrated pipelines achieve a better prediction of performance, which combines multiple computational models or modules with multidimensional features. Natural language processing (NLP) models also show the merits, which could enable discovery of novel features and, in turn, facilitate more precise effector prediction, extending our knowledge about each secretion mechanism.
Collapse
Affiliation(s)
- Ziyi Zhao
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen 518060, China
| | - Yixue Hu
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen 518060, China
| | - Yueming Hu
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Aaron P White
- Vaccine and Infectious Disease Organization (VIDO), University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Yejun Wang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen 518060, China; Department of Cell Biology and Genetics, College of Basic Medicine, Shenzhen University Medical School, Shenzhen 518060, China.
| |
Collapse
|
2
|
Lovelace AH, Dorhmi S, Hulin MT, Li Y, Mansfield JW, Ma W. Effector Identification in Plant Pathogens. PHYTOPATHOLOGY 2023; 113:637-650. [PMID: 37126080 DOI: 10.1094/phyto-09-22-0337-kd] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Effectors play a central role in determining the outcome of plant-pathogen interactions. As key virulence proteins, effectors are collectively indispensable for disease development. By understanding the virulence mechanisms of effectors, fundamental knowledge of microbial pathogenesis and disease resistance have been revealed. Effectors are also considered double-edged swords because some of them activate immunity in disease resistant plants after being recognized by specific immune receptors, which evolved to monitor pathogen presence or activity. Characterization of effector recognition by their cognate immune receptors and the downstream immune signaling pathways is instrumental in implementing resistance. Over the past decades, substantial research effort has focused on effector biology, especially concerning their interactions with virulence targets or immune receptors in plant cells. A foundation of this research is robust identification of the effector repertoire from a given pathogen, which depends heavily on bioinformatic prediction. In this review, we summarize methodologies that have been used for effector mining in various microbial pathogens which use different effector delivery mechanisms. We also discuss current limitations and provide perspectives on how recently developed analytic tools and technologies may facilitate effector identification and hence generation of a more complete vision of host-pathogen interactions. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
| | - Sara Dorhmi
- The Sainsbury Laboratory, Norwich, NR4 7UH, U.K
- Department of Microbiology and Plant Pathology, University of California Riverside, CA 92521, U.S.A
| | | | - Yufei Li
- The Sainsbury Laboratory, Norwich, NR4 7UH, U.K
| | - John W Mansfield
- Faculty of Natural Sciences, Imperial College London, London, SW7 2BX, U.K
| | - Wenbo Ma
- The Sainsbury Laboratory, Norwich, NR4 7UH, U.K
| |
Collapse
|
3
|
Pangenomic analysis reveals plant NAD + manipulation as an important virulence activity of bacterial pathogen effectors. Proc Natl Acad Sci U S A 2023; 120:e2217114120. [PMID: 36753463 PMCID: PMC9963460 DOI: 10.1073/pnas.2217114120] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
Nicotinamide adenine dinucleotide (NAD+) has emerged as a key component in prokaryotic and eukaryotic immune systems. The recent discovery that Toll/interleukin-1 receptor (TIR) proteins function as NAD+ hydrolases (NADase) links NAD+-derived small molecules with immune signaling. We investigated pathogen manipulation of host NAD+ metabolism as a virulence strategy. Using the pangenome of the model bacterial pathogen Pseudomonas syringae, we conducted a structure-based similarity search from 35,000 orthogroups for type III effectors (T3Es) with potential NADase activity. Thirteen T3Es, including five newly identified candidates, were identified that possess domain(s) characteristic of seven NAD+-hydrolyzing enzyme families. Most Pseudomonas syringae strains that depend on the type III secretion system to cause disease, encode at least one NAD+-manipulating T3E, and many have several. We experimentally confirmed the type III-dependent secretion of a novel T3E, named HopBY, which shows structural similarity to both TIR and adenosine diphosphate ribose (ADPR) cyclase. Homologs of HopBY were predicted to be type VI effectors in diverse bacterial species, indicating potential recruitment of this activity by microbial proteins secreted during various interspecies interactions. HopBY efficiently hydrolyzes NAD+ and specifically produces 2'cADPR, which can also be produced by TIR immune receptors of plants and by other bacteria. Intriguingly, this effector promoted bacterial virulence, indicating that 2'cADPR may not be the signaling molecule that directly initiates immunity. This study highlights a host-pathogen battleground centered around NAD+ metabolism and provides insight into the NAD+-derived molecules involved in plant immunity.
Collapse
|
4
|
Cooperative virulence via the collective action of secreted pathogen effectors. Nat Microbiol 2023; 8:640-650. [PMID: 36782026 DOI: 10.1038/s41564-023-01328-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/13/2023] [Indexed: 02/15/2023]
Abstract
Although virulence is typically attributed to single pathogenic strains, here we investigated whether effectors secreted by a population of non-virulent strains could function as public goods to enable the emergence of collective virulence. We disaggregated the 36 type III effectors of the phytopathogenic bacterium Pseudomonas syringae strain PtoDC3000 into a 'metaclone' of 36 coisogenic strains, each carrying a single effector in an effectorless background. Each coisogenic strain was individually unfit, but the metaclone was collectively as virulent as the wild-type strain on Arabidopsis thaliana, suggesting that effectors can drive the emergence of cooperation-based virulence through their public action. We show that independently evolved effector suits can equally drive this cooperative behaviour by transferring the effector alleles native to the strain PmaES4326 into the conspecific but divergent strain PtoDC3000. Finally, we transferred the disaggregated PtoDC3000 effector arsenal into Pseudomonas fluorescens and show that their cooperative action was sufficient to convert this rhizosphere-inhabiting beneficial bacterium into a phyllosphere pathogen. These results emphasize the importance of microbial community interactions and expand the ecological scale at which disease may be attributed.
Collapse
|
5
|
Bundalovic-Torma C, Lonjon F, Desveaux D, Guttman DS. Diversity, Evolution, and Function of Pseudomonas syringae Effectoromes. ANNUAL REVIEW OF PHYTOPATHOLOGY 2022; 60:211-236. [PMID: 35537470 DOI: 10.1146/annurev-phyto-021621-121935] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Pseudomonas syringae is an evolutionarily diverse bacterial species complex and a preeminent model for the study of plant-pathogen interactions due in part to its remarkably broad host range. A critical feature of P. syringae virulence is the employment of suites of type III secreted effector (T3SE) proteins, which vary widely in composition and function. These effectors act on a variety of plant intracellular targets to promote pathogenesis but can also be avirulence factors when detected by host immune complexes. In this review, we survey the phylogenetic diversity (PD) of the P. syringae effectorome, comprising 70 distinct T3SE families identified to date, and highlight how avoidance of host immune detection has shaped effectorome diversity through functional redundancy, diversification, and horizontal transfer. We present emerging avenues for research and novel insights that can be gained via future investigations of plant-pathogen interactions through the fusion of large-scale interaction screens and phylogenomic approaches.
Collapse
Affiliation(s)
| | - Fabien Lonjon
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario, Canada; ,
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
6
|
Bullones-Bolaños A, Bernal-Bayard J, Ramos-Morales F. The NEL Family of Bacterial E3 Ubiquitin Ligases. Int J Mol Sci 2022; 23:7725. [PMID: 35887072 PMCID: PMC9320238 DOI: 10.3390/ijms23147725] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 12/16/2022] Open
Abstract
Some pathogenic or symbiotic Gram-negative bacteria can manipulate the ubiquitination system of the eukaryotic host cell using a variety of strategies. Members of the genera Salmonella, Shigella, Sinorhizobium, and Ralstonia, among others, express E3 ubiquitin ligases that belong to the NEL family. These bacteria use type III secretion systems to translocate these proteins into host cells, where they will find their targets. In this review, we first introduce type III secretion systems and the ubiquitination process and consider the various ways bacteria use to alter the ubiquitin ligation machinery. We then focus on the members of the NEL family, their expression, translocation, and subcellular localization in the host cell, and we review what is known about the structure of these proteins, their function in virulence or symbiosis, and their specific targets.
Collapse
Affiliation(s)
| | | | - Francisco Ramos-Morales
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, 41012 Sevilla, Spain; (A.B.-B.); (J.B.-B.)
| |
Collapse
|
7
|
Martyn JE, Gomez-Valero L, Buchrieser C. The evolution and role of eukaryotic-like domains in environmental intracellular bacteria: the battle with a eukaryotic cell. FEMS Microbiol Rev 2022; 46:6529235. [DOI: 10.1093/femsre/fuac012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 02/09/2022] [Accepted: 02/14/2022] [Indexed: 11/14/2022] Open
Abstract
Abstract
Intracellular pathogens that are able to thrive in different environments, such as Legionella spp. which preferentially live in protozoa in aquatic environments or environmental Chlamydiae which replicate either within protozoa or a range of animals, possess a plethora of cellular biology tools to influence their eukaryotic host. The host manipulation tools that evolved in the interaction with protozoa, confer these bacteria the capacity to also infect phylogenetically distinct eukaryotic cells, such as macrophages and thus they can also be human pathogens. To manipulate the host cell, bacteria use protein secretion systems and molecular effectors. Although these molecular effectors are encoded in bacteria, they are expressed and function in a eukaryotic context often mimicking or inhibiting eukaryotic proteins. Indeed, many of these effectors have eukaryotic-like domains. In this review we propose that the main pathways environmental intracellular bacteria need to subvert in order to establish the host eukaryotic cell as a replication niche are chromatin remodelling, ubiquitination signalling, and modulation of protein-protein interactions via tandem repeat domains. We then provide mechanistic insight into how these proteins might have evolved as molecular weapons. Finally, we highlight that in environmental intracellular bacteria the number of eukaryotic-like domains and proteins is considerably higher than in intracellular bacteria specialised to an isolated niche, such as obligate intracellular human pathogens. As mimics of eukaryotic proteins are critical components of host pathogen interactions, this distribution of eukaryotic-like domains suggests that the environment has selected them.
Collapse
Affiliation(s)
- Jessica E Martyn
- Institut Pasteur, Biologie des Bactéries Intracellulaires and CNRS UMR 3525, Paris, France
| | - Laura Gomez-Valero
- Institut Pasteur, Biologie des Bactéries Intracellulaires and CNRS UMR 3525, Paris, France
| | - Carmen Buchrieser
- Institut Pasteur, Biologie des Bactéries Intracellulaires and CNRS UMR 3525, Paris, France
| |
Collapse
|
8
|
Martel A, Ruiz-Bedoya T, Breit-McNally C, Laflamme B, Desveaux D, Guttman DS. The ETS-ETI cycle: evolutionary processes and metapopulation dynamics driving the diversification of pathogen effectors and host immune factors. CURRENT OPINION IN PLANT BIOLOGY 2021; 62:102011. [PMID: 33677388 DOI: 10.1016/j.pbi.2021.102011] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/21/2021] [Accepted: 01/24/2021] [Indexed: 05/13/2023]
Abstract
The natural diversity of pathogen effectors and host immune components represents a snapshot of the underlying evolutionary processes driving the host-pathogen arms race. In plants, this arms race is manifested by an ongoing cycle of disease and resistance driven by pathogenic effectors that promote disease (effector-triggered susceptibility; ETS) and plant resistance proteins that recognize effector activity to trigger immunity (effector-triggered immunity; ETI). Here we discuss how this ongoing ETS-ETI cycle has shaped the natural diversity of both plant resistance proteins and pathogen effectors. We focus on the evolutionary forces that drive the diversification of the molecules that determine the outcome of plant-pathogen interactions and introduce the concept of metapopulation dynamics (i.e., the introduction of genetic variation from conspecific organisms in different populations) as an alternative mechanism that can introduce and maintain diversity in both host and pathogen populations.
Collapse
Affiliation(s)
- Alexandre Martel
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Tatiana Ruiz-Bedoya
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Clare Breit-McNally
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Bradley Laflamme
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada
| | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada; Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario M6S2Y1, Canada.
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, Ontario M6S2Y1, Canada; Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario M6S2Y1, Canada.
| |
Collapse
|
9
|
Dong S, Ma W. How to win a tug-of-war: the adaptive evolution of Phytophthora effectors. CURRENT OPINION IN PLANT BIOLOGY 2021; 62:102027. [PMID: 33684881 DOI: 10.1016/j.pbi.2021.102027] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 01/26/2021] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
The 'zigzag' model formulates some of the fundamental principles underpinning the dynamic interactions between pathogen effectors and plant immunity. As key virulence factors, effectors often exhibit a pattern of rapid evolution, presumably as a result of the host-pathogen arms race. Here, we summarize the current knowledge of mechanisms that may accelerate effector evolution in the highly successful Phytophthora pathogens. Recent findings on epigenetic regulation of effector genes that allows evasion of host recognition and maintenance of cost/benefit balance, and a conserved structural unit in effector proteins that may promote the evolution of virulence activities are highlighted.
Collapse
Affiliation(s)
- Suomeng Dong
- Department of Plant Pathology and Key Laboratory of Plant Immunity, Nanjing Agricultural University, Nanjing, 210095, China.
| | - Wenbo Ma
- The Sainsbury Laboratory, Norwich Research Park, Norwich, NR4 7UH, United Kingdom; Department of Microbiology and Plant Pathology, University of California, Riverside, CA 92521, USA.
| |
Collapse
|
10
|
Su J, Nguyen QM, Kimble A, Pike SM, Kim SH, Gassmann W. The Conserved Arginine Required for AvrRps4 Processing Is Also Required for Recognition of Its N-Terminal Fragment in Lettuce. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:270-278. [PMID: 33147120 DOI: 10.1094/mpmi-10-20-0285-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Pathogens utilize a repertoire of effectors to facilitate pathogenesis, but when the host recognizes one of them, it causes effector-triggered immunity. The Pseudomonas type III effector AvrRps4 is a bipartite effector that is processed in planta into a functional 133-amino acid N-terminus (AvrRps4-N) and 88-amino acid C-terminus (AvrRps4-C). Previous studies found AvrRps4-C to be sufficient to trigger the hypersensitive response (HR) in turnip. In contrast, our recent work found that AvrRps4-N but not AvrRps4-C triggered HR in lettuce, whereas both were required for resistance induction in Arabidopsis. Here, we initially compared AvrRps4 recognition by turnip and lettuce using transient expression. By serial truncation, we identified the central conserved region consisting of 37 amino acids as essential for AvrRps4-N recognition, whereas the putative type III secretion signal peptide or the C-terminal 13 amino acids were dispensable. Surprisingly, the conserved arginine at position 112 (R112) that is required for full-length AvrRps4 processing is also required for the recognition of AvrRps4-N by lettuce. Mutating R112 to hydrophobic leucine or negatively charged glutamate abolished the HR-inducing capacity of AvrRps4-N, while a positively charged lysine at this position resulted in a slow and weak HR. Together, our results suggest an AvrRps4-N recognition-specific role of R112 in lettuce.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
Collapse
Affiliation(s)
- Jianbin Su
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, U.S.A
- Christopher S. Bond Life Sciences Center and Interdisciplinary Plant Group, University of Missouri, Columbia, MO 66211, U.S.A
| | - Quang-Minh Nguyen
- Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Korea
| | - Ashten Kimble
- Christopher S. Bond Life Sciences Center and Interdisciplinary Plant Group, University of Missouri, Columbia, MO 66211, U.S.A
- Division of Biological Sciences, University of Columbia, MO 65211, U.S.A
| | - Sharon M Pike
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, U.S.A
- Christopher S. Bond Life Sciences Center and Interdisciplinary Plant Group, University of Missouri, Columbia, MO 66211, U.S.A
| | - Sang Hee Kim
- Division of Applied Life Science (BK21 Plus), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Korea
| | - Walter Gassmann
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, U.S.A
- Christopher S. Bond Life Sciences Center and Interdisciplinary Plant Group, University of Missouri, Columbia, MO 66211, U.S.A
| |
Collapse
|
11
|
Meyer MD, Ryck JD, Goormachtig S, Van Damme P. Keeping in Touch with Type-III Secretion System Effectors: Mass Spectrometry-Based Proteomics to Study Effector-Host Protein-Protein Interactions. Int J Mol Sci 2020; 21:E6891. [PMID: 32961832 PMCID: PMC7555288 DOI: 10.3390/ijms21186891] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 09/15/2020] [Accepted: 09/16/2020] [Indexed: 01/03/2023] Open
Abstract
Manipulation of host cellular processes by translocated bacterial effectors is key to the success of bacterial pathogens and some symbionts. Therefore, a comprehensive understanding of effectors is of critical importance to understand infection biology. It has become increasingly clear that the identification of host protein targets contributes invaluable knowledge to the characterization of effector function during pathogenesis. Recent advances in mapping protein-protein interaction networks by means of mass spectrometry-based interactomics have enabled the identification of host targets at large-scale. In this review, we highlight mass spectrometry-driven proteomics strategies and recent advances to elucidate type-III secretion system effector-host protein-protein interactions. Furthermore, we highlight approaches for defining spatial and temporal effector-host interactions, and discuss possible avenues for studying natively delivered effectors in the context of infection. Overall, the knowledge gained when unravelling effector complexation with host factors will provide novel opportunities to control infectious disease outcomes.
Collapse
Affiliation(s)
- Margaux De Meyer
- Department of Biochemistry and Microbiology, Ghent University, K. L. Ledeganckstraat 35, 9000 Ghent, Belgium; (M.D.M.); (J.D.R.)
- VIB Center for Medical Biotechnology, Technologiepark 75, 9052 Zwijnaarde, Belgium
| | - Joren De Ryck
- Department of Biochemistry and Microbiology, Ghent University, K. L. Ledeganckstraat 35, 9000 Ghent, Belgium; (M.D.M.); (J.D.R.)
- VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Zwijnaarde, Belgium;
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium
| | - Sofie Goormachtig
- VIB Center for Plant Systems Biology, Technologiepark 71, 9052 Zwijnaarde, Belgium;
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 71, 9052 Zwijnaarde, Belgium
| | - Petra Van Damme
- Department of Biochemistry and Microbiology, Ghent University, K. L. Ledeganckstraat 35, 9000 Ghent, Belgium; (M.D.M.); (J.D.R.)
| |
Collapse
|
12
|
Abstract
Many Gram-negative bacteria infect hosts and cause diseases by translocating a variety of type III secreted effectors (T3SEs) into the host cell cytoplasm. However, despite a dramatic increase in the number of available whole-genome sequences, it remains challenging for accurate prediction of T3SEs. Traditional prediction models have focused on atypical sequence features buried in the N-terminal peptides of T3SEs, but unfortunately, these models have had high false-positive rates. In this research, we integrated promoter information along with characteristic protein features for signal regions, chaperone-binding domains, and effector domains for T3SE prediction. Machine learning algorithms, including deep learning, were adopted to predict the atypical features mainly buried in signal sequences of T3SEs, followed by development of a voting-based ensemble model integrating the individual prediction results. We assembled this into a unified T3SE prediction pipeline, T3SEpp, which integrated the results of individual modules, resulting in high accuracy (i.e., ∼0.94) and >1-fold reduction in the false-positive rate compared to that of state-of-the-art software tools. The T3SEpp pipeline and sequence features observed here will facilitate the accurate identification of new T3SEs, with numerous benefits for future studies on host-pathogen interactions.IMPORTANCE Type III secreted effector (T3SE) prediction remains a big computational challenge. In practical applications, current software tools often suffer problems of high false-positive rates. One of the causal factors could be the relatively unitary type of biological features used for the design and training of the models. In this research, we made a comprehensive survey on the sequence-based features of T3SEs, including signal sequences, chaperone-binding domains, effector domains, and transcription factor binding promoter sites, and assembled a unified prediction pipeline integrating multi-aspect biological features within homology-based and multiple machine learning models. To our knowledge, we have compiled the most comprehensive biological sequence feature analysis for T3SEs in this research. The T3SEpp pipeline integrating the variety of features and assembling different models showed high accuracy, which should facilitate more accurate identification of T3SEs in new and existing bacterial whole-genome sequences.
Collapse
|
13
|
Laflamme B, Dillon MM, Martel A, Almeida RND, Desveaux D, Guttman DS. The pan-genome effector-triggered immunity landscape of a host-pathogen interaction. Science 2020; 367:763-768. [PMID: 32054757 DOI: 10.1126/science.aax4079] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 10/18/2019] [Accepted: 01/17/2020] [Indexed: 12/24/2022]
Abstract
Effector-triggered immunity (ETI), induced by host immune receptors in response to microbial effectors, protects plants against virulent pathogens. However, a systematic study of ETI prevalence against species-wide pathogen diversity is lacking. We constructed the Pseudomonas syringae Type III Effector Compendium (PsyTEC) to reduce the pan-genome complexity of 5127 unique effector proteins, distributed among 70 families from 494 strains, to 529 representative alleles. We screened PsyTEC on the model plant Arabidopsis thaliana and identified 59 ETI-eliciting alleles (11.2%) from 19 families (27.1%), with orthologs distributed among 96.8% of P. syringae strains. We also identified two previously undescribed host immune receptors, including CAR1, which recognizes the conserved effectors AvrE and HopAA1, and found that 94.7% of strains harbor alleles predicted to be recognized by either CAR1 or ZAR1.
Collapse
Affiliation(s)
- Bradley Laflamme
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Marcus M Dillon
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Alexandre Martel
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Renan N D Almeida
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada
| | - Darrell Desveaux
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada.
| | - David S Guttman
- Department of Cell and Systems Biology, University of Toronto, Toronto, ON M5S 3B2, Canada. .,Center for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON M5S 3B2, Canada
| |
Collapse
|
14
|
Zalguizuri A, Caetano-Anollés G, Lepek VC. Phylogenetic profiling, an untapped resource for the prediction of secreted proteins and its complementation with sequence-based classifiers in bacterial type III, IV and VI secretion systems. Brief Bioinform 2020; 20:1395-1402. [PMID: 29394318 DOI: 10.1093/bib/bby009] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 01/15/2018] [Indexed: 12/29/2022] Open
Abstract
In the establishment and maintenance of the interaction between pathogenic or symbiotic bacteria with a eukaryotic organism, protein substrates of specialized bacterial secretion systems called effectors play a critical role once translocated into the host cell. Proteins are also secreted to the extracellular medium by free-living bacteria or directly injected into other competing organisms to hinder or kill. In this work, we explore an approach based on the evolutionary dependence that most of the effectors maintain with their specific secretion system that analyzes the co-occurrence of any orthologous protein group and their corresponding secretion system across multiple genomes. We compared and complemented our methodology with sequence-based machine learning prediction tools for the type III, IV and VI secretion systems. Finally, we provide the predictive results for the three secretion systems in 1606 complete genomes at http://www.iib.unsam.edu.ar/orgsissec/.
Collapse
|
15
|
de Laia ML, Moreira LM, Gonçalves JF, Ferro MIT, Rodrigues ACP, dos Santos JN, Felestrino ÉB, Ferro JA. Gene expression analysis identifies hypothetical genes that may be critical during the infection process of Xanthomonas citri subsp. citri. ELECTRON J BIOTECHN 2019. [DOI: 10.1016/j.ejbt.2019.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
|
16
|
Dillon MM, Almeida RN, Laflamme B, Martel A, Weir BS, Desveaux D, Guttman DS. Molecular Evolution of Pseudomonas syringae Type III Secreted Effector Proteins. FRONTIERS IN PLANT SCIENCE 2019; 10:418. [PMID: 31024592 PMCID: PMC6460904 DOI: 10.3389/fpls.2019.00418] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 03/19/2019] [Indexed: 05/02/2023]
Abstract
Diverse Gram-negative pathogens like Pseudomonas syringae employ type III secreted effector (T3SE) proteins as primary virulence factors that combat host immunity and promote disease. T3SEs can also be recognized by plant hosts and activate an effector triggered immune (ETI) response that shifts the interaction back toward plant immunity. Consequently, T3SEs are pivotal in determining the virulence potential of individual P. syringae strains, and ultimately help to restrict P. syringae pathogens to a subset of potential hosts that are unable to recognize their repertoires of T3SEs. While a number of effector families are known to be present in the P. syringae species complex, one of the most persistent challenges has been documenting the complex variation in T3SE contents across a diverse collection of strains. Using the entire pan-genome of 494 P. syringae strains isolated from more than 100 hosts, we conducted a global analysis of all known and putative T3SEs. We identified a total of 14,613 putative T3SEs, 4,636 of which were unique at the amino acid level, and show that T3SE repertoires of different P. syringae strains vary dramatically, even among strains isolated from the same hosts. We also find substantial diversification within many T3SE families, and in many cases find strong signatures of positive selection. Furthermore, we identify multiple gene gain and loss events for several families, demonstrating an important role of horizontal gene transfer (HGT) in the evolution of P. syringae T3SEs. These analyses provide insight into the evolutionary history of P. syringae T3SEs as they co-evolve with the host immune system, and dramatically expand the database of P. syringae T3SEs alleles.
Collapse
Affiliation(s)
- Marcus M. Dillon
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Renan N.D. Almeida
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Bradley Laflamme
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | - Alexandre Martel
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | | | - Darrell Desveaux
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada
| | - David S. Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
- Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
17
|
Patel S, Wall DM, Castillo A, McCormick BA. Caspase-3 cleavage of Salmonella type III secreted effector protein SifA is required for localization of functional domains and bacterial dissemination. Gut Microbes 2019; 10:172-187. [PMID: 30727836 PMCID: PMC6546311 DOI: 10.1080/19490976.2018.1506668] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
SifA is a bi-functional Type III Secretion System (T3SS) effector protein that plays an important role in Salmonella virulence. The N-terminal domain of SifA binds SifA-Kinesin-Interacting-Protein (SKIP), and via an interaction with kinesin, forms tubular membrane extensions called Sif filaments (Sifs) that emanate from the Salmonella Containing Vacuole (SCV). The C-terminal domain of SifA harbors a WxxxE motif that functions to mimic active host cell GTPases. Taken together, SifA functions in inducing endosomal tubulation in order to maintain the integrity of the SCV and promote bacterial dissemination. Since SifA performs multiple, unrelated functions, the objective of this study was to determine how each functional domain of SifA becomes processed. Our work demonstrates that a linker region containing a caspase-3 cleavage motif separates the two functional domains of SifA. To test the hypothesis that processing of SifA by caspase-3 at this particular site is required for function and proper localization of the effector protein domains, we developed two tracking methods to analyze the intracellular localization of SifA. We first adapted a fluorescent tag called phiLOV that allowed for type-III secretion system (T3SS) mediated delivery of SifA and observation of its intracellular colocalization with caspase-3. Additionally, we created a dual-tagging strategy that permitted tracking of each of the SifA functional domains following caspase-3 cleavage to different subcellular locations. The results of this study reveal that caspase-3 cleavage of SifA is required for the proper localization of functional domains and bacterial dissemination. Considering the importance of these events in Salmonella pathogenesis, we conclude that caspase-3 cleavage of effector proteins is a more broadly applicable effector processing mechanism utilized by Salmonella to invade and persist during infection.
Collapse
Affiliation(s)
- Samir Patel
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA,CONTACT Beth McCormick Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, 368 Plantation Street AS8-2011, Worcester, MA 01605, USA
| | - Daniel M. Wall
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Antonio Castillo
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Beth A. McCormick
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| |
Collapse
|
18
|
Recombination of ecologically and evolutionarily significant loci maintains genetic cohesion in the Pseudomonas syringae species complex. Genome Biol 2019; 20:3. [PMID: 30606234 PMCID: PMC6317194 DOI: 10.1186/s13059-018-1606-y] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 12/06/2018] [Indexed: 01/25/2023] Open
Abstract
Background Pseudomonas syringae is a highly diverse bacterial species complex capable of causing a wide range of serious diseases on numerous agronomically important crops. We examine the evolutionary relationships of 391 agricultural and environmental strains using whole-genome sequencing and evolutionary genomic analyses. Results We describe the phylogenetic distribution of all 77,728 orthologous gene families in the pan-genome, reconstruct the core genome phylogeny using the 2410 core genes, hierarchically cluster the accessory genome, identify the diversity and distribution of type III secretion systems and their effectors, predict ecologically and evolutionary relevant loci, and establish the molecular evolutionary processes operating on gene families. Phylogenetic and recombination analyses reveals that the species complex is subdivided into primary and secondary phylogroups, with the former primarily comprised of agricultural isolates, including all of the well-studied P. syringae strains. In contrast, the secondary phylogroups include numerous environmental isolates. These phylogroups also have levels of genetic diversity typically found among distinct species. An analysis of rates of recombination within and between phylogroups revealed a higher rate of recombination within primary phylogroups than between primary and secondary phylogroups. We also find that “ecologically significant” virulence-associated loci and “evolutionarily significant” loci under positive selection are over-represented among loci that undergo inter-phylogroup genetic exchange. Conclusions While inter-phylogroup recombination occurs relatively rarely, it is an important force maintaining the genetic cohesion of the species complex, particularly among primary phylogroup strains. This level of genetic cohesion, and the shared plant-associated niche, argues for considering the primary phylogroups as a single biological species. Electronic supplementary material The online version of this article (10.1186/s13059-018-1606-y) contains supplementary material, which is available to authorized users.
Collapse
|
19
|
Norkowski S, Schmidt MA, Rüter C. The species-spanning family of LPX-motif harbouring effector proteins. Cell Microbiol 2018; 20:e12945. [PMID: 30137651 DOI: 10.1111/cmi.12945] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/09/2018] [Accepted: 08/14/2018] [Indexed: 12/13/2022]
Abstract
The delivery of effector proteins into infected eukaryotic cells represents a key virulence feature of many microbial pathogens in order to derail essential cellular processes and effectively counter the host defence system. Although bacterial effectors are truly numerous and exhibit a wide range of biochemical activities, commonalities in terms of protein structure and function shared by many bacterial pathogens exist. Recent progress has shed light on a species-spanning family of bacterial effectors containing an LPX repeat motif as a subtype of the leucine-rich repeat superfamily, partially combined with a novel E3 ubiquitin ligase domain. This review highlights the immunomodulatory effects of LPX effector proteins, with particular emphasis on the exploitation of the host ubiquitin system.
Collapse
Affiliation(s)
- Stefanie Norkowski
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), University of Münster, Münster, Germany
| | - M Alexander Schmidt
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), University of Münster, Münster, Germany
| | - Christian Rüter
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), University of Münster, Münster, Germany
| |
Collapse
|
20
|
Zhang Y, Huang J, Ochola SO, Dong S. Functional Analysis of PsAvr3c Effector Family From Phytophthora Provides Probes to Dissect SKRP Mediated Plant Susceptibility. FRONTIERS IN PLANT SCIENCE 2018; 9:1105. [PMID: 30090111 PMCID: PMC6069499 DOI: 10.3389/fpls.2018.01105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 07/09/2018] [Indexed: 05/28/2023]
Abstract
PsAvr3c is an effector identified from oomycete plant pathogen Phytophthora sojae that causes soybean root and stem rot disease. Earlier studies have demonstrated that PsAvr3c binds to a novel soybean spliceosomal complex protein, GmSKRP, to reprogram the splicing of hundreds of pre-mRNAs and consequently subvert host immunity. PsAvr3c family genes are present in some other Phytophthora species, but their function remains unknown. Here, we characterized the functions of PsAvh27b (PsAvr3c paralog from P. sojae), ProbiAvh89 and PparvAvh214 (orthologs from P. cinnamomi var. robiniae and Phytophthora parvispora, respectively). The study reveals that both PsAvh27b and ProbiAvh89 interact with GmSKRPs in vitro, and stabilize GmSKRP1 in vivo. However, PparvAvh214 cannot interact with GmSKRPs proteins. The qRT-PCR result illustrates that the alternative splicing of pre-mRNAs of several soybean defense-related genes are altered in PsAvh27b and ProbiAvh89 when over-expressed on soybean hairy roots. Moreover, PsAvr3c family members display differences in promoting Phytophthora infection in a SKRP-dependent manner. Overall, this study highlights that the effector-mediated host pre-mRNA alternative splicing occurs in other pathosystems, thus providing new probes to further dissect SKRP-mediated plant susceptibility.
Collapse
Affiliation(s)
- Ying Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Jie Huang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Sylvans O. Ochola
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Suomeng Dong
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
- Key Laboratory of Integrated Management of Crop Diseases and Pests, Ministry of Education, Nanjing Agricultural University, Nanjing, Chxsina
| |
Collapse
|
21
|
The bacterial type III-secreted protein AvrRps4 is a bipartite effector. PLoS Pathog 2018; 14:e1006984. [PMID: 29601603 PMCID: PMC5895054 DOI: 10.1371/journal.ppat.1006984] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 04/11/2018] [Accepted: 03/20/2018] [Indexed: 11/21/2022] Open
Abstract
Bacterial effector proteins secreted into host plant cells manipulate those cells to the benefit of the pathogen, but effector-triggered immunity (ETI) occurs when effectors are recognized by host resistance proteins. The RPS4/RRS1 pair recognizes the Pseudomonas syringae pv. pisi effector AvrRps4. AvrRps4 is processed in planta into AvrRps4N (133 amino acids), homologous to the N-termini of other effectors including the native P. syringae pv. tomato strain DC3000 effector HopK1, and AvrRps4C (88 amino acids). Previous data suggested that AvrRps4C alone is necessary and sufficient for resistance when overexpressed in heterologous systems. We show that delivering AvrRps4C from DC3000, but not from a DC3000 hopK1- strain, triggers resistance in the Arabidopsis accession Col-0. Delivering AvrRps4C in tandem with AvrRps4N, or as a chimera with HopK1N, fully complements AvrRps4-triggered immunity. AvrRps4N in the absence of AvrRps4C enhances virulence in Col-0. In addition, AvrRps4N triggers a hypersensitive response in lettuce that is attenuated by coexpression of AvrRps4C, further supporting the role of AvrRps4N as a bona fide effector domain. Based on these results we propose that evolutionarily, fusion of AvrRps4C to AvrRps4N may have counteracted recognition of AvrRps4N, and that the plant RPS4/RRS1 resistance gene pair was selected as a countermeasure. We conclude that AvrRps4 represents an unusual chimeric effector, with recognition in Arabidopsis by RPS4/RRS1 requiring the presence of both processed effector moieties. An important component of the plant immune system relies on the detection of pathogen-derived effectors by immune receptors called resistance proteins. Bacterial pathogens inject effectors into the host cell via a dedicated secretion system to suppress defenses and to manipulate the physiology of the host cell to the pathogen's advantage. Usually, a single resistance protein recognizes a single effector, but an increasing number of exceptions and elaborations on this one-to-one relationship are known. The plant Arabidopsis uses a pair of resistance proteins, RRS1 and RPS4, to detect the effector AvrRps4. After injection into the cell, AvrRps4 is cleaved into two protein parts, and it had been assumed that only the C-terminal part needs to be present to trigger RPS4/RRS1. We show here that both AvrRps4 parts are required for triggering resistance in Arabidopsis, and that the N-terminal part, which previously had been assumed to only function in effector secretion into the host cell, in fact on its own has some functions of an effector. This conclusion is supported by the observation that the N-terminal part of AvrRps4 is sufficient to trigger resistance in lettuce. The fusion of the two AvrRps4 parts may have arisen to counteract plant defenses.
Collapse
|
22
|
Harms A, Liesch M, Körner J, Québatte M, Engel P, Dehio C. A bacterial toxin-antitoxin module is the origin of inter-bacterial and inter-kingdom effectors of Bartonella. PLoS Genet 2017; 13:e1007077. [PMID: 29073136 PMCID: PMC5675462 DOI: 10.1371/journal.pgen.1007077] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 11/07/2017] [Accepted: 10/16/2017] [Indexed: 12/22/2022] Open
Abstract
Host-targeting type IV secretion systems (T4SS) evolved from conjugative T4SS machineries that mediate interbacterial plasmid transfer. However, the origins of effectors secreted by these virulence devices have remained largely elusive. Previous work showed that some effectors exhibit homology to toxins of bacterial toxin-antitoxin modules, but the evolutionary trajectories underlying these ties had not been resolved. We previously reported that FicT toxins of FicTA toxin-antitoxin modules disrupt cellular DNA topology via their enzymatic FIC (filamentation induced by cAMP) domain. Intriguingly, the FIC domain of the FicT toxin VbhT of Bartonella schoenbuchensis is fused to a type IV secretion signal–the BID (Bep intracellular delivery) domain—similar to the Bartonella effector proteins (Beps) that are secreted into eukaryotic host cells via the host-targeting VirB T4SS. In this study, we show that the VbhT toxin is an interbacterial effector protein secreted via the conjugative Vbh T4SS that is closely related to the VirB T4SS and encoded by plasmid pVbh of B. schoenbuchensis. We therefore propose that the Vbh T4SS together with its effector VbhT represent an evolutionary missing link on a path that leads from a regular conjugation system and FicTA toxin-antitoxin modules to the VirB T4SS and the Beps. Intriguingly, phylogenetic analyses revealed that the fusion of FIC and BID domains has probably occurred independently in VbhT and the common ancestor of the Beps, suggesting parallel evolutionary paths. Moreover, several other examples of TA module toxins that are bona fide substrates of conjugative T4SS indicate that their recruitment as interbacterial effectors is prevalent and serves yet unknown biological functions in the context of bacterial conjugation. We propose that the adaptation for interbacterial transfer favors the exaptation of FicT and other TA module toxins as inter-kingdom effectors and may thus constitute an important stepping stone in the evolution of host-targeted effector proteins. Many bacterial pathogens use secretion systems to translocate effector proteins into host cells where they manipulate cell functions in favor of the pathogen. It is well-known that these secretion systems evolved from ancestors with functions in genuine bacterial contexts, but the origins of their secreted effectors have largely remained elusive. In this article we studied the evolutionary history of a host-targeting effector secretion system of the mammalian pathogen Bartonella that belongs to a group of machineries descended from secretion systems originally mediating DNA transfer between bacterial cells. Intriguingly, we found that such a DNA transfer machinery closely related to the host-targeting secretion system of Bartonella has recruited a bacterial protein involved in modulating DNA topology as an interbacterial effector protein that is translocated together with the DNA into recipient cells. The overall setup of this interbacterial effector is remarkably similar to the host-targeted effectors of Bartonella, and we propose that it represents an evolutionary missing link on the path from a genuine bacterial protein to effectors that manipulates host cell functioning. Further analyses showed that interbacterial effectors in DNA transfer may be a more common phenomenon and represent an important reservoir for the evolution of new host-targeted effectors.
Collapse
Affiliation(s)
- Alexander Harms
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Marius Liesch
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Jonas Körner
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Maxime Québatte
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Philipp Engel
- Department of Fundamental Microbiology, University of Lausanne, Lausanne, Switzerland
| | - Christoph Dehio
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
- * E-mail:
| |
Collapse
|
23
|
Lo T, Koulena N, Seto D, Guttman DS, Desveaux D. The HopF family of Pseudomonas syringae type III secreted effectors. MOLECULAR PLANT PATHOLOGY 2017; 18:457-468. [PMID: 27061875 PMCID: PMC6638241 DOI: 10.1111/mpp.12412] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Pseudomonas syringae is a bacterial phytopathogen that utilizes the type III secretion system to inject effector proteins into plant host cells. Pseudomonas syringae can infect a wide range of plant hosts, including agronomically important crops such as tomatoes and beans. The ability of P. syringae to infect such numerous hosts is caused, in part, by the diversity of effectors employed by this phytopathogen. Over 60 different effector families exist in P. syringae; one such family is HopF, which contains over 100 distinct alleles. Despite this diversity, research has focused on only two members of this family: HopF1 from P. syringae pathovar phaseolicola 1449B and HopF2 from P. syringae pathovar tomato DC3000. In this study, we review the research on HopF family members, including their host targets and molecular mechanisms of immunity suppression, and their enzymatic function. We also provide a phylogenetic analysis of this expanding effector family which provides a basis for a proposed nomenclature to guide future research. The extensive genetic diversity that exists within the HopF family presents a great opportunity to study how functional diversification on an effector family contributes to host specialization.
Collapse
Affiliation(s)
- Timothy Lo
- Department of Cell & Systems BiologyUniversity of Toronto25 Willcocks St.TorontoONCanadaM5S 3B2
| | - Noushin Koulena
- Department of Cell & Systems BiologyUniversity of Toronto25 Willcocks St.TorontoONCanadaM5S 3B2
| | - Derek Seto
- Department of Cell & Systems BiologyUniversity of Toronto25 Willcocks St.TorontoONCanadaM5S 3B2
| | - David S. Guttman
- Department of Cell & Systems BiologyUniversity of Toronto25 Willcocks St.TorontoONCanadaM5S 3B2
- Centre for the Analysis of Genome Evolution & FunctionUniversity of TorontoTorontoONCanada
| | - Darrell Desveaux
- Department of Cell & Systems BiologyUniversity of Toronto25 Willcocks St.TorontoONCanadaM5S 3B2
- Centre for the Analysis of Genome Evolution & FunctionUniversity of TorontoTorontoONCanada
| |
Collapse
|
24
|
Schuebel F, Rocker A, Edelmann D, Schessner J, Brieke C, Meinhart A. 3'-NADP and 3'-NAADP, Two Metabolites Formed by the Bacterial Type III Effector AvrRxo1. J Biol Chem 2016; 291:22868-22880. [PMID: 27621317 PMCID: PMC5087710 DOI: 10.1074/jbc.m116.751297] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/01/2016] [Indexed: 12/12/2022] Open
Abstract
An arsenal of effector proteins is injected by bacterial pathogens into the host cell or its vicinity to increase virulence. The commonly used top-down approaches inferring the toxic mechanism of individual effector proteins from the host's phenotype are often impeded by multiple targets of different effectors as well as by their pleiotropic effects. Here we describe our bottom-up approach, showing that the bacterial type III effector AvrRxo1 of plant pathogens is an authentic phosphotransferase that produces two novel metabolites by phosphorylating nicotinamide/nicotinic acid adenine dinucleotide at the adenosine 3′-hydroxyl group. Both products of AvrRxo1, 3′-NADP and 3′-nicotinic acid adenine dinucleotide phosphate (3′-NAADP), are substantially different from the ubiquitous co-enzyme 2′-NADP and the calcium mobilizer 2′-NAADP. Interestingly, 3′-NADP and 3′-NAADP have previously been used as inhibitors or signaling molecules but were regarded as “artificial” compounds so far. Our findings now necessitate a shift in thinking about the biological importance of 3′-phosphorylated NAD derivatives.
Collapse
Affiliation(s)
- Felix Schuebel
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Andrea Rocker
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Daniel Edelmann
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Julia Schessner
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Clara Brieke
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| | - Anton Meinhart
- From the Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, Jahnstrasse 29, 69120 Heidelberg, Germany
| |
Collapse
|
25
|
Jacques MA, Arlat M, Boulanger A, Boureau T, Carrère S, Cesbron S, Chen NWG, Cociancich S, Darrasse A, Denancé N, Fischer-Le Saux M, Gagnevin L, Koebnik R, Lauber E, Noël LD, Pieretti I, Portier P, Pruvost O, Rieux A, Robène I, Royer M, Szurek B, Verdier V, Vernière C. Using Ecology, Physiology, and Genomics to Understand Host Specificity in Xanthomonas. ANNUAL REVIEW OF PHYTOPATHOLOGY 2016; 54:163-87. [PMID: 27296145 DOI: 10.1146/annurev-phyto-080615-100147] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
How pathogens coevolve with and adapt to their hosts are critical to understanding how host jumps and/or acquisition of novel traits can lead to new disease emergences. The Xanthomonas genus includes Gram-negative plant-pathogenic bacteria that collectively infect a broad range of crops and wild plant species. However, individual Xanthomonas strains usually cause disease on only a few plant species and are highly adapted to their hosts, making them pertinent models to study host specificity. This review summarizes our current understanding of the molecular basis of host specificity in the Xanthomonas genus, with a particular focus on the ecology, physiology, and pathogenicity of the bacterium. Despite our limited understanding of the basis of host specificity, type III effectors, microbe-associated molecular patterns, lipopolysaccharides, transcriptional regulators, and chemotactic sensors emerge as key determinants for shaping host specificity.
Collapse
Affiliation(s)
- Marie-Agnès Jacques
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Matthieu Arlat
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, F-31062 Toulouse, France
| | - Alice Boulanger
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, F-31062 Toulouse, France
| | - Tristan Boureau
- Université Angers, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France;
| | - Sébastien Carrère
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
| | - Sophie Cesbron
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Nicolas W G Chen
- Agrocampus Ouest, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France;
| | - Stéphane Cociancich
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| | - Armelle Darrasse
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Nicolas Denancé
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Marion Fischer-Le Saux
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Lionel Gagnevin
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Ralf Koebnik
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Emmanuelle Lauber
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
| | - Laurent D Noël
- INRA, UMR 441 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France; , , , ,
- CNRS, UMR 2594 Laboratoire des Interactions Plantes Micro-organismes (LIPM), F-31326 Castanet-Tolosan, France
| | - Isabelle Pieretti
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| | - Perrine Portier
- INRA, UMR 1345 Institut de Recherche en Horticulture et Semences (IRHS), F-49071 Beaucouzé, France; , , , , ,
| | - Olivier Pruvost
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410 Saint-Pierre, La Réunion, France; , ,
| | - Adrien Rieux
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410 Saint-Pierre, La Réunion, France; , ,
| | - Isabelle Robène
- CIRAD, UMR Peuplements Végétaux et Bioagresseurs en Milieu Tropical (PVBMT), F-97410 Saint-Pierre, La Réunion, France; , ,
| | - Monique Royer
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| | - Boris Szurek
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Valérie Verdier
- IRD, CIRAD, University of Montpellier, Interactions Plantes Micro-organismes Environnement (IPME), F-34394 Montpellier, France; , , ,
| | - Christian Vernière
- CIRAD, UMR Biologie et Génétique des Interactions Plante-Parasite (BGPI), F-34398 Montpellier, France; , , ,
| |
Collapse
|
26
|
Thakur S, Guttman DS. A De-Novo Genome Analysis Pipeline (DeNoGAP) for large-scale comparative prokaryotic genomics studies. BMC Bioinformatics 2016; 17:260. [PMID: 27363390 PMCID: PMC4929753 DOI: 10.1186/s12859-016-1142-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 06/22/2016] [Indexed: 11/10/2022] Open
Abstract
Background Comparative analysis of whole genome sequence data from closely related prokaryotic species or strains is becoming an increasingly important and accessible approach for addressing both fundamental and applied biological questions. While there are number of excellent tools developed for performing this task, most scale poorly when faced with hundreds of genome sequences, and many require extensive manual curation. Results We have developed a de-novo genome analysis pipeline (DeNoGAP) for the automated, iterative and high-throughput analysis of data from comparative genomics projects involving hundreds of whole genome sequences. The pipeline is designed to perform reference-assisted and de novo gene prediction, homolog protein family assignment, ortholog prediction, functional annotation, and pan-genome analysis using a range of proven tools and databases. While most existing methods scale quadratically with the number of genomes since they rely on pairwise comparisons among predicted protein sequences, DeNoGAP scales linearly since the homology assignment is based on iteratively refined hidden Markov models. This iterative clustering strategy enables DeNoGAP to handle a very large number of genomes using minimal computational resources. Moreover, the modular structure of the pipeline permits easy updates as new analysis programs become available. Conclusion DeNoGAP integrates bioinformatics tools and databases for comparative analysis of a large number of genomes. The pipeline offers tools and algorithms for annotation and analysis of completed and draft genome sequences. The pipeline is developed using Perl, BioPerl and SQLite on Ubuntu Linux version 12.04 LTS. Currently, the software package accompanies script for automated installation of necessary external programs on Ubuntu Linux; however, the pipeline should be also compatible with other Linux and Unix systems after necessary external programs are installed. DeNoGAP is freely available at https://sourceforge.net/projects/denogap/. Electronic supplementary material The online version of this article (doi:10.1186/s12859-016-1142-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Shalabh Thakur
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada
| | - David S Guttman
- Department of Cell & Systems Biology, University of Toronto, Toronto, ON, Canada. .,Centre for the Analysis of Genome Evolution and Function, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
27
|
AnnoTALE: bioinformatics tools for identification, annotation, and nomenclature of TALEs from Xanthomonas genomic sequences. Sci Rep 2016; 6:21077. [PMID: 26876161 PMCID: PMC4753510 DOI: 10.1038/srep21077] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 01/18/2016] [Indexed: 12/16/2022] Open
Abstract
Transcription activator-like effectors (TALEs) are virulence factors, produced by the bacterial plant-pathogen Xanthomonas, that function as gene activators inside plant cells. Although the contribution of individual TALEs to infectivity has been shown, the specific roles of most TALEs, and the overall TALE diversity in Xanthomonas spp. is not known. TALEs possess a highly repetitive DNA-binding domain, which is notoriously difficult to sequence. Here, we describe an improved method for characterizing TALE genes by the use of PacBio sequencing. We present ‘AnnoTALE’, a suite of applications for the analysis and annotation of TALE genes from Xanthomonas genomes, and for grouping similar TALEs into classes. Based on these classes, we propose a unified nomenclature for Xanthomonas TALEs that reveals similarities pointing to related functionalities. This new classification enables us to compare related TALEs and to identify base substitutions responsible for the evolution of TALE specificities.
Collapse
|
28
|
Han Q, Zhou C, Wu S, Liu Y, Triplett L, Miao J, Tokuhisa J, Deblais L, Robinson H, Leach JE, Li J, Zhao B. Crystal Structure of Xanthomonas AvrRxo1-ORF1, a Type III Effector with a Polynucleotide Kinase Domain, and Its Interactor AvrRxo1-ORF2. Structure 2015; 23:1900-1909. [PMID: 26344722 DOI: 10.1016/j.str.2015.06.030] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2015] [Revised: 05/19/2015] [Accepted: 06/30/2015] [Indexed: 12/27/2022]
Abstract
Xanthomonas oryzae pv. oryzicola (Xoc) causes bacterial leaf streak (BLS) disease on rice plants. Xoc delivers a type III effector AvrRxo1-ORF1 into rice plant cells that can be recognized by disease resistance (R) protein Rxo1, and triggers resistance to BLS disease. However, the mechanism and virulence role of AvrRxo1 is not known. In the genome of Xoc, AvrRxo1-ORF1 is adjacent to another gene AvrRxo1-ORF2, which was predicted to encode a molecular chaperone of AvrRxo1-ORF1. We report the co-purification and crystallization of the AvrRxo1-ORF1:AvrRxo1-ORF2 tetramer complex at 1.64 Å resolution. AvrRxo1-ORF1 has a T4 polynucleotide kinase domain, and expression of AvrRxo1-ORF1 suppresses bacterial growth in a manner dependent on the kinase motif. Although AvrRxo1-ORF2 binds AvrRxo1-ORF1, it is structurally different from typical effector-binding chaperones, in that it has a distinct fold containing a novel kinase-binding domain. AvrRxo1-ORF2 functions to suppress the bacteriostatic activity of AvrRxo1-ORF1 in bacterial cells.
Collapse
Affiliation(s)
- Qian Han
- Laboratory of Tropical Veterinary Medicine and Vector Biology, and Hainan Key Laboratory of Sustainable Utilization of Tropical Bioresources, College of Agriculture, Hainan University, Haikou 570228, Hainan, China; Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA
| | - Changhe Zhou
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
| | - Shuchi Wu
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
| | - Yi Liu
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
| | - Lindsay Triplett
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523-1177, USA
| | - Jiamin Miao
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
| | - James Tokuhisa
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA
| | - Loïc Deblais
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523-1177, USA
| | - Howard Robinson
- Biology Department, Brookhaven National Laboratory, Upton, NY 11973, USA
| | - Jan E Leach
- Department of Bioagricultural Sciences and Pest Management, Colorado State University, Fort Collins, CO 80523-1177, USA
| | - Jianyong Li
- Department of Biochemistry, Virginia Tech, Blacksburg, VA 24061, USA.
| | - Bingyu Zhao
- Department of Horticulture, Virginia Tech, Blacksburg, VA 24061, USA.
| |
Collapse
|
29
|
Dong X, Lu X, Zhang Z. BEAN 2.0: an integrated web resource for the identification and functional analysis of type III secreted effectors. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2015; 2015:bav064. [PMID: 26120140 PMCID: PMC4483310 DOI: 10.1093/database/bav064] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 06/02/2015] [Indexed: 11/13/2022]
Abstract
Gram-negative pathogenic bacteria inject type III secreted effectors (T3SEs) into host cells to sabotage their immune signaling networks. Because T3SEs constitute a meeting-point of pathogen virulence and host defense, they are of keen interest to host-pathogen interaction research community. To accelerate the identification and functional understanding of T3SEs, we present BEAN 2.0 as an integrated web resource to predict, analyse and store T3SEs. BEAN 2.0 includes three major components. First, it provides an accurate T3SE predictor based on a hybrid approach. Using independent testing data, we show that BEAN 2.0 achieves a sensitivity of 86.05% and a specificity of 100%. Second, it integrates a set of online sequence analysis tools. Users can further perform functional analysis of putative T3SEs in a seamless way, such as subcellular location prediction, functional domain scan and disorder region annotation. Third, it compiles a database covering 1215 experimentally verified T3SEs and constructs two T3SE-related networks that can be used to explore the relationships among T3SEs. Taken together, by presenting a one-stop T3SE bioinformatics resource, we hope BEAN 2.0 can promote comprehensive understanding of the function and evolution of T3SEs.
Collapse
Affiliation(s)
- Xiaobao Dong
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Xiaotian Lu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Ziding Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| |
Collapse
|
30
|
Kemen AC, Agler MT, Kemen E. Host-microbe and microbe-microbe interactions in the evolution of obligate plant parasitism. THE NEW PHYTOLOGIST 2015; 206:1207-28. [PMID: 25622918 DOI: 10.1111/nph.13284] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/12/2014] [Indexed: 05/03/2023]
Abstract
Research on obligate biotrophic plant parasites, which reproduce only on living hosts, has revealed a broad diversity of filamentous microbes that have independently acquired complex morphological structures, such as haustoria. Genome studies have also demonstrated a concerted loss of genes for metabolism and lytic enzymes, and gain of diversity of genes coding for effectors involved in host defense suppression. So far, these traits converge in all known obligate biotrophic parasites, but unexpected genome plasticity remains. This plasticity is manifested as transposable element (TE)-driven increases in genome size, observed to be associated with the diversification of virulence genes under selection pressure. Genome expansion could result from the governing of the pathogen response to ecological selection pressures, such as host or nutrient availability, or to microbial interactions, such as competition, hyperparasitism and beneficial cooperations. Expansion is balanced by alternating sexual and asexual cycles, as well as selfing and outcrossing, which operate to control transposon activity in populations. In turn, the prevalence of these balancing mechanisms seems to be correlated with external biotic factors, suggesting a complex, interconnected evolutionary network in host-pathogen-microbe interactions. Therefore, the next phase of obligate biotrophic pathogen research will need to uncover how this network, including multitrophic interactions, shapes the evolution and diversity of pathogens.
Collapse
Affiliation(s)
- Ariane C Kemen
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829, Cologne, Germany
| | - Matthew T Agler
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829, Cologne, Germany
| | - Eric Kemen
- Max Planck Research Group Fungal Biodiversity, Max Planck Institute for Plant Breeding Research, Carl-von-Linne Weg 10, 50829, Cologne, Germany
| |
Collapse
|
31
|
A Ralstonia solanacearum type III effector directs the production of the plant signal metabolite trehalose-6-phosphate. mBio 2014; 5:mBio.02065-14. [PMID: 25538193 PMCID: PMC4278537 DOI: 10.1128/mbio.02065-14] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The plant pathogen Ralstonia solanacearum possesses two genes encoding a trehalose-6-phosphate synthase (TPS), an enzyme of the trehalose biosynthetic pathway. One of these genes, named ripTPS, was found to encode a protein with an additional N-terminal domain which directs its translocation into host plant cells through the type 3 secretion system. RipTPS is a conserved effector in the R. solanacearum species complex, and homologues were also detected in other bacterial plant pathogens. Functional analysis of RipTPS demonstrated that this type 3 effector synthesizes trehalose-6-phosphate and identified residues essential for this enzymatic activity. Although trehalose-6-phosphate is a key signal molecule in plants that regulates sugar status and carbon assimilation, the disruption of ripTPS did not alter the virulence of R. solanacearum on plants. However, heterologous expression assays showed that this effector specifically elicits a hypersensitive-like response on tobacco that is independent of its enzymatic activity and is triggered by the C-terminal half of the protein. Recognition of this effector by the plant immune system is suggestive of a role during the infectious process. Ralstonia solanacearum, the causal agent of bacterial wilt disease, infects more than two hundred plant species, including economically important crops. The type III secretion system plays a major role in the pathogenicity of this bacterium, and approximately 70 effector proteins have been shown to be translocated into host plant cells. This study provides the first description of a type III effector endowed with a trehalose-6-phosphate synthase enzymatic activity and illustrates a new mechanism by which the bacteria may manipulate the plant metabolism upon infection. In recent years, trehalose-6-phosphate has emerged as an essential signal molecule in plants, connecting plant metabolism and development. The finding that a bacterial pathogen could induce the production of trehalose-6-phosphate in plant cells further highlights the importance of this metabolite in multiple aspects of the molecular physiology of plants.
Collapse
|
32
|
Siamer S, Dehio C. New insights into the role of Bartonella effector proteins in pathogenesis. Curr Opin Microbiol 2014; 23:80-5. [PMID: 25461577 DOI: 10.1016/j.mib.2014.11.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/06/2014] [Accepted: 11/07/2014] [Indexed: 10/24/2022]
Abstract
The facultative intracellular bacteria Bartonella spp. share a common infection strategy to invade and colonize mammals in a host-specific manner. Following transmission by blood-sucking arthropods, Bartonella are inoculated in the derma and then spread, via two sequential enigmatic niches, to the blood stream where they cause a long-lasting intra-erythrocytic bacteraemia. The VirB/VirD4 type IV secretion system (VirB/D4 T4SS) is essential for the pathogenicity of most Bartonella species by injecting an arsenal of effector proteins into host cells. These bacterial effector proteins share a modular architecture, comprising domains and/or motifs that confer an array of functions. Here, we review recent advances in understanding the function and evolutionary origin of this fascinating repertoire of host-targeted bacterial effectors.
Collapse
Affiliation(s)
- Sabrina Siamer
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Christoph Dehio
- Focal Area Infection Biology, Biozentrum, University of Basel, Basel, Switzerland.
| |
Collapse
|
33
|
Wall DM, McCormick BA. Bacterial secreted effectors and caspase-3 interactions. Cell Microbiol 2014; 16:1746-56. [PMID: 25262664 PMCID: PMC4257569 DOI: 10.1111/cmi.12368] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/10/2014] [Accepted: 09/15/2014] [Indexed: 12/29/2022]
Abstract
Apoptosis is a critical process that intrinsically links organism survival to its ability to induce controlled death. Thus, functional apoptosis allows organisms to remove perceived threats to their survival by targeting those cells that it determines pose a direct risk. Central to this process are apoptotic caspases, enzymes that form a signalling cascade, converting danger signals via initiator caspases into activation of the executioner caspase, caspase-3. This enzyme begins disassembly of the cell by activating DNA degrading enzymes and degrading the cellular architecture. Interaction of pathogenic bacteria with caspases, and in particular, caspase-3, can therefore impact both host cell and bacterial survival. With roles outside cell death such as cell differentiation, control of signalling pathways and immunomodulation also being described for caspase-3, bacterial interactions with caspase-3 may be of far more significance in infection than previously recognized. In this review, we highlight the ways in which bacterial pathogens have evolved to subvert caspase-3 both through effector proteins that directly interact with the enzyme or by modulating pathways that influence its activation and activity.
Collapse
Affiliation(s)
- Daniel M Wall
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow, G12 8QQ, UK
| | | |
Collapse
|
34
|
Abstract
Bacteriophage genomes found in a range of bacterial pathogens encode a diverse array of virulence factors ranging from superantigens or pore forming lysins to numerous exotoxins. Recent studies have uncovered an entirely new class of bacterial virulence factors, called effector proteins or effector toxins, which are encoded within phage genomes that reside among several pathovars of Escherichia coli and Salmonella enterica. These effector proteins have multiple domains resulting in proteins that can be multifunctional. The effector proteins encoded within phage genomes are translocated directly from the bacterial cytosol into their eukaryotic target cells by specialized bacterial type three secretion systems (T3SSs). In this review, we will give an overview of the different types of effector proteins encoded within phage genomes and examine their roles in bacterial pathogenesis.
Collapse
Affiliation(s)
- E Fidelma Boyd
- Department of Biological Sciences; University of Delaware; Newark, DE USA
| | | | | |
Collapse
|
35
|
Bao Z, Stodghill PV, Myers CR, Lam H, Wei HL, Chakravarthy S, Kvitko BH, Collmer A, Cartinhour SW, Schweitzer P, Swingle B. Genomic plasticity enables phenotypic variation of Pseudomonas syringae pv. tomato DC3000. PLoS One 2014; 9:e86628. [PMID: 24516535 PMCID: PMC3916326 DOI: 10.1371/journal.pone.0086628] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Accepted: 12/16/2013] [Indexed: 11/18/2022] Open
Abstract
Whole genome sequencing revealed the presence of a genomic anomaly in the region of 4.7 to 4.9 Mb of the Pseudomonas syringae pv. tomato (Pst) DC3000 genome. The average read depth coverage of Pst DC3000 whole genome sequencing results suggested that a 165 kb segment of the chromosome had doubled in copy number. Further analysis confirmed the 165 kb duplication and that the two copies were arranged as a direct tandem repeat. Examination of the corresponding locus in Pst NCPPB1106, the parent strain of Pst DC3000, suggested that the 165 kb duplication most likely formed after the two strains diverged via transposition of an ISPsy5 insertion sequence (IS) followed by unequal crossing over between ISPsy5 elements at each end of the duplicated region. Deletion of one copy of the 165 kb region demonstrated that the duplication facilitated enhanced growth in some culture conditions, but did not affect pathogenic growth in host tomato plants. These types of chromosomal structures are predicted to be unstable and we have observed resolution of the 165 kb duplication to single copy and its subsequent re-duplication. These data demonstrate the role of IS elements in recombination events that facilitate genomic reorganization in P. syringae.
Collapse
Affiliation(s)
- Zhongmeng Bao
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Paul V. Stodghill
- United States Department of Agriculture-Agricultural Research Service, Ithaca, New York, United States of America
| | - Christopher R. Myers
- Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, New York, United States of America
| | - Hanh Lam
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Hai-Lei Wei
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Suma Chakravarthy
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Brian H. Kvitko
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America
| | - Alan Collmer
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Samuel W. Cartinhour
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
- United States Department of Agriculture-Agricultural Research Service, Ithaca, New York, United States of America
| | - Peter Schweitzer
- Biotechnology Resource Center, Cornell University, Ithaca, New York, United States of America
| | - Bryan Swingle
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
- United States Department of Agriculture-Agricultural Research Service, Ithaca, New York, United States of America
- * E-mail:
| |
Collapse
|
36
|
Mucyn TS, Yourstone S, Lind AL, Biswas S, Nishimura MT, Baltrus DA, Cumbie JS, Chang JH, Jones CD, Dangl JL, Grant SR. Variable suites of non-effector genes are co-regulated in the type III secretion virulence regulon across the Pseudomonas syringae phylogeny. PLoS Pathog 2014; 10:e1003807. [PMID: 24391493 PMCID: PMC3879358 DOI: 10.1371/journal.ppat.1003807] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2013] [Accepted: 10/17/2013] [Indexed: 01/12/2023] Open
Abstract
Pseudomonas syringae is a phylogenetically diverse species of Gram-negative bacterial plant pathogens responsible for crop diseases around the world. The HrpL sigma factor drives expression of the major P. syringae virulence regulon. HrpL controls expression of the genes encoding the structural and functional components of the type III secretion system (T3SS) and the type three secreted effector proteins (T3E) that are collectively essential for virulence. HrpL also regulates expression of an under-explored suite of non-type III effector genes (non-T3E), including toxin production systems and operons not previously associated with virulence. We implemented and refined genome-wide transcriptional analysis methods using cDNA-derived high-throughput sequencing (RNA-seq) data to characterize the HrpL regulon from six isolates of P. syringae spanning the diversity of the species. Our transcriptomes, mapped onto both complete and draft genomes, significantly extend earlier studies. We confirmed HrpL-regulation for a majority of previously defined T3E genes in these six strains. We identified two new T3E families from P. syringae pv. oryzae 1_6, a strain within the relatively underexplored phylogenetic Multi-Locus Sequence Typing (MLST) group IV. The HrpL regulons varied among strains in gene number and content across both their T3E and non-T3E gene suites. Strains within MLST group II consistently express the lowest number of HrpL-regulated genes. We identified events leading to recruitment into, and loss from, the HrpL regulon. These included gene gain and loss, and loss of HrpL regulation caused by group-specific cis element mutations in otherwise conserved genes. Novel non-T3E HrpL-regulated genes include an operon that we show is required for full virulence of P. syringae pv. phaseolicola 1448A on French bean. We highlight the power of integrating genomic, transcriptomic, and phylogenetic information to drive concise functional experimentation and to derive better insight into the evolution of virulence across an evolutionarily diverse pathogen species.
Collapse
Affiliation(s)
- Tatiana S Mucyn
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Scott Yourstone
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Program in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Abigail L Lind
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Surojit Biswas
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Marc T Nishimura
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - David A Baltrus
- School of Plant Sciences, The University of Arizona, Tucson, Arizona, United States of America
| | - Jason S Cumbie
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America ; Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, United States of America
| | - Jeff H Chang
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America ; Molecular and Cellular Biology Program, Oregon State University, Corvallis, Oregon, United States of America ; Center for Genome Research and Biocomputing, Oregon State University, Corvallis, Oregon, United States of America
| | - Corbin D Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Program in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Jeffery L Dangl
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Program in Bioinformatics and Computational Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Carolina Center for Genome Sciences, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Howard Hughes Medical Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Sarah R Grant
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America ; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| |
Collapse
|
37
|
Host immune responses accelerate pathogen evolution. ISME JOURNAL 2013; 8:727-731. [PMID: 24304673 DOI: 10.1038/ismej.2013.215] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Revised: 10/27/2013] [Accepted: 10/28/2013] [Indexed: 12/14/2022]
Abstract
Pathogens face a hostile and often novel environment when infecting a new host, and adaptation is likely to be an important determinant of the success in colonization and establishment. We hypothesized that resistant hosts will impose stronger selection on pathogens than susceptible hosts, which should accelerate pathogen evolution through selection biased toward effector genes. To test this hypothesis, we conducted an experimental evolution study on Xanthomonas citri subsp. citri (Xcc) in a susceptible plant species and a resistant plant species. We performed 55 rounds of repeated reinoculation of Xcc through susceptible host grapefruit (isolates G1, G2, G3) and resistant host kumquat (isolates K1, K2, K3). Consequently, only K1 and K3 isolates lost their ability to elicit a hypersensitive response (HR) in kumquat. Illumina sequencing of the parental and descendant strains P, G1, G2, G3, K1, K2 and K3 revealed that fixed mutations were biased toward type three secretion system effectors in isolates K1 and K3. Parallel evolution was observed in the K1 and K3 strains, suggesting that the mutations result from selection rather than by random drift. Our results support our hypothesis and suggest that repeated infection of resistant hosts by pathogens should be prevented to avoid selecting for adaptive pathogens.
Collapse
|
38
|
Goss EM, Press CM, Grünwald NJ. Evolution of RXLR-class effectors in the oomycete plant pathogen Phytophthora ramorum. PLoS One 2013; 8:e79347. [PMID: 24244484 PMCID: PMC3820680 DOI: 10.1371/journal.pone.0079347] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Accepted: 09/26/2013] [Indexed: 12/02/2022] Open
Abstract
Phytophthora plant pathogens contain many hundreds of effectors potentially involved in infection of host plants. Comparative genomic analyses have shown that these effectors evolve rapidly and have been subject to recent expansions. We examined the recent sequence evolution of RXLR-class effector gene families in the sudden oak death pathogen, P. ramorum. We found that P. ramorum RXLR effectors have taken multiple evolutionary paths, including loss or gain of repeated domains, recombination or gene conversion among paralogs, and selection on point mutations. Sequencing of homologs from two subfamilies in P. ramorum’s closest known relatives revealed repeated gene duplication and divergence since speciation with P. lateralis. One family showed strong signatures of recombination while the other family has evolved primarily by point mutation. Comparison of a small number of the hundreds of RXLR-class effectors across three clonal lineages of P. ramorum shows striking divergence in alleles among lineages, suggesting the potential for functional differences between lineages. Our results suggest future avenues for examination of rapidly evolving effectors in P. ramorum, including investigation of the functional and coevolutionary significance of the patterns of sequence evolution that we observed.
Collapse
Affiliation(s)
- Erica M. Goss
- Horticultural Crops Research Laboratory, Department of Agriculture Agricultural Research Service, Corvallis, Oregon, United States of America
- * E-mail:
| | - Caroline M. Press
- Horticultural Crops Research Laboratory, Department of Agriculture Agricultural Research Service, Corvallis, Oregon, United States of America
| | - Niklaus J. Grünwald
- Horticultural Crops Research Laboratory, Department of Agriculture Agricultural Research Service, Corvallis, Oregon, United States of America
| |
Collapse
|
39
|
Darrasse A, Carrère S, Barbe V, Boureau T, Arrieta-Ortiz ML, Bonneau S, Briand M, Brin C, Cociancich S, Durand K, Fouteau S, Gagnevin L, Guérin F, Guy E, Indiana A, Koebnik R, Lauber E, Munoz A, Noël LD, Pieretti I, Poussier S, Pruvost O, Robène-Soustrade I, Rott P, Royer M, Serres-Giardi L, Szurek B, van Sluys MA, Verdier V, Vernière C, Arlat M, Manceau C, Jacques MA. Genome sequence of Xanthomonas fuscans subsp. fuscans strain 4834-R reveals that flagellar motility is not a general feature of xanthomonads. BMC Genomics 2013; 14:761. [PMID: 24195767 PMCID: PMC3826837 DOI: 10.1186/1471-2164-14-761] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/26/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Xanthomonads are plant-associated bacteria responsible for diseases on economically important crops. Xanthomonas fuscans subsp. fuscans (Xff) is one of the causal agents of common bacterial blight of bean. In this study, the complete genome sequence of strain Xff 4834-R was determined and compared to other Xanthomonas genome sequences. RESULTS Comparative genomics analyses revealed core characteristics shared between Xff 4834-R and other xanthomonads including chemotaxis elements, two-component systems, TonB-dependent transporters, secretion systems (from T1SS to T6SS) and multiple effectors. For instance a repertoire of 29 Type 3 Effectors (T3Es) with two Transcription Activator-Like Effectors was predicted. Mobile elements were associated with major modifications in the genome structure and gene content in comparison to other Xanthomonas genomes. Notably, a deletion of 33 kbp affects flagellum biosynthesis in Xff 4834-R. The presence of a complete flagellar cluster was assessed in a collection of more than 300 strains representing different species and pathovars of Xanthomonas. Five percent of the tested strains presented a deletion in the flagellar cluster and were non-motile. Moreover, half of the Xff strains isolated from the same epidemic than 4834-R was non-motile and this ratio was conserved in the strains colonizing the next bean seed generations. CONCLUSIONS This work describes the first genome of a Xanthomonas strain pathogenic on bean and reports the existence of non-motile xanthomonads belonging to different species and pathovars. Isolation of such Xff variants from a natural epidemic may suggest that flagellar motility is not a key function for in planta fitness.
Collapse
Affiliation(s)
- Armelle Darrasse
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Sébastien Carrère
- INRA, LIPM UMR 441, F-31326, Castanet-Tolosan, France
- CNRS, LIPM UMR 2594, F-31326, Castanet-Tolosan, France
| | - Valérie Barbe
- CEA, Genoscope, Centre National de Séquençage, F-91057, Evry Cedex, France
| | - Tristan Boureau
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Mario L Arrieta-Ortiz
- Universidad de Los Andes, Laboratorio de Micología y Fitopatología Uniandes, Bogotá, Colombia
- current address: Department of Biology, Center for Genomics and Systems Biology, New York University, 10003, New York, NY, USA
| | - Sophie Bonneau
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Martial Briand
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Chrystelle Brin
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | | | - Karine Durand
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Stéphanie Fouteau
- CEA, Genoscope, Centre National de Séquençage, F-91057, Evry Cedex, France
| | - Lionel Gagnevin
- CIRAD, UMR PVBMT, F-97410, Saint-Pierre, La Réunion, France
- Université de la Réunion, UMR PVBMT, F-97715, Saint-Denis, La Réunion, France
| | - Fabien Guérin
- CIRAD, UMR PVBMT, F-97410, Saint-Pierre, La Réunion, France
- Université de la Réunion, UMR PVBMT, F-97715, Saint-Denis, La Réunion, France
| | - Endrick Guy
- INRA, LIPM UMR 441, F-31326, Castanet-Tolosan, France
- CNRS, LIPM UMR 2594, F-31326, Castanet-Tolosan, France
| | - Arnaud Indiana
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Ralf Koebnik
- IRD, UMR RPB, F-34394, Montpellier Cedex 5, France
| | - Emmanuelle Lauber
- INRA, LIPM UMR 441, F-31326, Castanet-Tolosan, France
- CNRS, LIPM UMR 2594, F-31326, Castanet-Tolosan, France
| | - Alejandra Munoz
- Universidad de Los Andes, Laboratorio de Micología y Fitopatología Uniandes, Bogotá, Colombia
| | - Laurent D Noël
- INRA, LIPM UMR 441, F-31326, Castanet-Tolosan, France
- CNRS, LIPM UMR 2594, F-31326, Castanet-Tolosan, France
| | | | - Stéphane Poussier
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
- Université de la Réunion, UMR PVBMT, F-97715, Saint-Denis, La Réunion, France
| | - Olivier Pruvost
- CIRAD, UMR PVBMT, F-97410, Saint-Pierre, La Réunion, France
- Université de la Réunion, UMR PVBMT, F-97715, Saint-Denis, La Réunion, France
| | - Isabelle Robène-Soustrade
- CIRAD, UMR PVBMT, F-97410, Saint-Pierre, La Réunion, France
- Université de la Réunion, UMR PVBMT, F-97715, Saint-Denis, La Réunion, France
| | - Philippe Rott
- CIRAD, UMR BGPI, F-34398, Montpellier Cedex 5, France
| | - Monique Royer
- CIRAD, UMR BGPI, F-34398, Montpellier Cedex 5, France
| | - Laurana Serres-Giardi
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| | - Boris Szurek
- IRD, UMR RPB, F-34394, Montpellier Cedex 5, France
| | | | | | - Christian Vernière
- CIRAD, UMR PVBMT, F-97410, Saint-Pierre, La Réunion, France
- Université de la Réunion, UMR PVBMT, F-97715, Saint-Denis, La Réunion, France
| | - Matthieu Arlat
- INRA, LIPM UMR 441, F-31326, Castanet-Tolosan, France
- CNRS, LIPM UMR 2594, F-31326, Castanet-Tolosan, France
- Université de Toulouse, Université Paul Sabatier, UMR LIPM, F-31326, Castanet-Tolosan Cedex, France
| | - Charles Manceau
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
- current address: ANSES, Laboratoire de Santé des végétaux, F-49044, Angers, France
| | - Marie-Agnès Jacques
- INRA, UMR1345 Institut de Recherche en Horticulture et Semences, F-49071, Beaucouzé, France
- AGROCAMPUS OUEST, UMR1345 Institut de Recherche en Horticulture et Semences, F-49045, Angers, France
- Université d’Angers, UMR1345 Institut de Recherche en Horticulture et Semences, SFR 4207 QUASAV, PRES L’UNAM, F-49045, Angers, France
| |
Collapse
|
40
|
Elzinga DA, Jander G. The role of protein effectors in plant-aphid interactions. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:451-6. [PMID: 23850072 DOI: 10.1016/j.pbi.2013.06.018] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Revised: 06/19/2013] [Accepted: 06/24/2013] [Indexed: 05/04/2023]
Abstract
Aphid salivary proteins, which are injected into the phloem sieve elements during feeding, play a central role in plant-aphid interactions. Among the dozens of known salivary proteins, many have no homology to proteins from other organisms. These aphid-specific proteins likely have evolved as effectors that inhibit plant defenses, prevent phloem sieve-element occlusion, and otherwise promote the unique phloem feeding style. However, aphid salivary proteins also are recognized by plants to mount defense responses and are likely a major factor in limiting the host range of particular aphid species and biotypes. Newly developed research tools provide excellent opportunities for analyzing the mostly unknown functions of aphid salivary proteins and elucidating their contribution to the complex interactions between aphids and their host plants.
Collapse
Affiliation(s)
- Dezi A Elzinga
- Boyce Thompson Institute for Plant Research, Ithaca, NY 14853, USA
| | | |
Collapse
|
41
|
Shen D, Liu T, Ye W, Liu L, Liu P, Wu Y, Wang Y, Dou D. Gene duplication and fragment recombination drive functional diversification of a superfamily of cytoplasmic effectors in Phytophthora sojae. PLoS One 2013; 8:e70036. [PMID: 23922898 PMCID: PMC3726527 DOI: 10.1371/journal.pone.0070036] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2013] [Accepted: 06/14/2013] [Indexed: 11/19/2022] Open
Abstract
Phytophthora and other oomycetes secrete a large number of putative host cytoplasmic effectors with conserved FLAK motifs following signal peptides, termed crinkling and necrosis inducing proteins (CRN), or Crinkler. Here, we first investigated the evolutionary patterns and mechanisms of CRN effectors in Phytophthora sojae and compared them to two other Phytophthora species. The genes encoding CRN effectors could be divided into 45 orthologous gene groups (OGG), and most OGGs unequally distributed in the three species, in which each underwent large number of gene gains or losses, indicating that the CRN genes expanded after species evolution in Phytophthora and evolved through pathoadaptation. The 134 expanded genes in P. sojae encoded family proteins including 82 functional genes and expressed at higher levels while the other 68 genes encoding orphan proteins were less expressed and contained 50 pseudogenes. Furthermore, we demonstrated that most expanded genes underwent gene duplication or/and fragment recombination. Three different mechanisms that drove gene duplication or recombination were identified. Finally, the expanded CRN effectors exhibited varying pathogenic functions, including induction of programmed cell death (PCD) and suppression of PCD through PAMP-triggered immunity or/and effector-triggered immunity. Overall, these results suggest that gene duplication and fragment recombination may be two mechanisms that drive the expansion and neofunctionalization of the CRN family in P. sojae, which aids in understanding the roles of CRN effectors within each oomycete pathogen.
Collapse
Affiliation(s)
- Danyu Shen
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Tingli Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Li Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Peihan Liu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Yuren Wu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
| | - Daolong Dou
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, China
- * E-mail:
| |
Collapse
|
42
|
Wang Y, Sun M, Bao H, Zhang Q, Guo D. Effective identification of bacterial type III secretion signals using joint element features. PLoS One 2013; 8:e59754. [PMID: 23593149 PMCID: PMC3617162 DOI: 10.1371/journal.pone.0059754] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Accepted: 02/18/2013] [Indexed: 11/18/2022] Open
Abstract
Type III secretion system (T3SS) plays important roles in bacteria and host cell interactions by specifically translocating type III effectors into the cytoplasm of the host cells. The N-terminal amino acid sequences of the bacterial type III effectors determine their specific secretion via type III secretion conduits. It is still unclear as to how the N-terminal sequences guide this specificity. In this work, the amino acid composition, secondary structure, and solvent accessibility in the N-termini of type III and non-type III secreted proteins were compared and contrasted. A high-efficacy mathematical model based on these joint features was developed to distinguish the type III proteins from the non-type III ones. The results indicate that secondary structure and solvent accessibility may make important contribution to the specific recognition of type III secretion signals. Analysis also showed that the joint feature of the N-terminal 6th–10th amino acids are especially important for guiding specific type III secretion. Furthermore, a genome-wide screening was performed to predict Salmonella type III secreted proteins, and 8 new candidates were experimentally validated. Interestingly, type III secretion signals were also predicted in gram-positive bacteria and yeasts. Experimental validation showed that two candidates from yeast can indeed be secreted through Salmonella type III secretion conduit. This research provides the first line of direct evidence that secondary structure and solvent accessibility contain important features for guiding specific type III secretion. The new software based on these joint features ensures a high accuracy (general cross-validation sensitivity of ∼96% at a specificity of ∼98%) in silico identification of new type III secreted proteins, which may facilitate our understanding about the specificity of type III secretion and the evolution of type III secreted proteins.
Collapse
Affiliation(s)
- Yejun Wang
- School of Life Sciences and the State Key Lab of Agrobiotechnology, the Chinese University of Hong Kong, Shatin, NT, Hong Kong
| | | | | | | | | |
Collapse
|
43
|
Silva DS, Pereira LMG, Moreira AR, Ferreira-da-Silva F, Brito RM, Faria TQ, Zornetta I, Montecucco C, Oliveira P, Azevedo JE, Pereira PJB, Macedo-Ribeiro S, do Vale A, dos Santos NMS. The apoptogenic toxin AIP56 is a metalloprotease A-B toxin that cleaves NF-κb P65. PLoS Pathog 2013; 9:e1003128. [PMID: 23468618 PMCID: PMC3585134 DOI: 10.1371/journal.ppat.1003128] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Accepted: 11/28/2012] [Indexed: 12/15/2022] Open
Abstract
AIP56 (apoptosis-inducing protein of 56 kDa) is a major virulence factor of Photobacterium damselae piscicida (Phdp), a Gram-negative pathogen that causes septicemic infections, which are among the most threatening diseases in mariculture. The toxin triggers apoptosis of host macrophages and neutrophils through a process that, in vivo, culminates with secondary necrosis of the apoptotic cells contributing to the necrotic lesions observed in the diseased animals. Here, we show that AIP56 is a NF-κB p65-cleaving zinc-metalloprotease whose catalytic activity is required for the apoptogenic effect. Most of the bacterial effectors known to target NF-κB are type III secreted effectors. In contrast, we demonstrate that AIP56 is an A-B toxin capable of acting at distance, without requiring contact of the bacteria with the target cell. We also show that the N-terminal domain cleaves NF-κB at the Cys39-Glu40 peptide bond and that the C-terminal domain is involved in binding and internalization into the cytosol. The apoptosis inducing protein of 56 kDa (AIP56) is a key virulence factor secreted by Photobacterium damselae piscicida (Phdp), a Gram-negative bacterium that causes septicaemic infections in economically important marine fish species. It is known that AIP56 induces massive destruction of the phagocytic cells of the infected host, allowing the extracellular multiplication of the bacteria and contributing to the genesis of the pathology. Here we show that AIP56 acts by cleaving NF-κB p65. The NF-κB family of transcription factors is evolutionarily conserved and plays a central role in the host responses to microbial pathogen invasion, regulating the expression of inflammatory and anti-apoptotic genes. Pathogenic bacteria have evolved complex strategies to interfere with NF-κB signalling, usually by injecting protein effectors directly into the cell's cytosol through bacterial secretion machineries that require contact with host cells. In contrast, AIP56 acts at distance and has an intrinsic ability to reach the cytosol due to the presence of a C-terminal domain that functions as “delivery module.”
Collapse
Affiliation(s)
- Daniela S. Silva
- Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Liliana M. G. Pereira
- Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Ana R. Moreira
- Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Frederico Ferreira-da-Silva
- Protein Production and Purification, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Rui M. Brito
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
- Chemistry Department, Faculty of Science and Technology, University of Coimbra, Coimbra, Portugal
| | - Tiago Q. Faria
- Center for Neuroscience and Cell Biology (CNC), University of Coimbra, Coimbra, Portugal
| | - Irene Zornetta
- Dipartimento di Scienze Biomediche dell'Università di Padova and Instituto di Neuroscienze del CNR, Padova, Italy
| | - Cesare Montecucco
- Dipartimento di Scienze Biomediche dell'Università di Padova and Instituto di Neuroscienze del CNR, Padova, Italy
| | - Pedro Oliveira
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Jorge E. Azevedo
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
- Organelle Biogenesis and Function, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Pedro J. B. Pereira
- Biomolecular Structure, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Sandra Macedo-Ribeiro
- Protein Crystallography, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Ana do Vale
- Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
| | - Nuno M. S. dos Santos
- Fish Immunology and Vaccinology, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Porto, Portugal
- * E-mail:
| |
Collapse
|
44
|
Carrión VJ, Gutiérrez-Barranquero JA, Arrebola E, Bardaji L, Codina JC, de Vicente A, Cazorla FM, Murillo J. The mangotoxin biosynthetic operon (mbo) is specifically distributed within Pseudomonas syringae genomospecies 1 and was acquired only once during evolution. Appl Environ Microbiol 2013; 79:756-67. [PMID: 23144138 PMCID: PMC3568555 DOI: 10.1128/aem.03007-12] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Accepted: 11/07/2012] [Indexed: 11/20/2022] Open
Abstract
Mangotoxin production was first described in Pseudomonas syringae pv. syringae strains. A phenotypic characterization of 94 P. syringae strains was carried out to determine the genetic evolution of the mangotoxin biosynthetic operon (mbo). We designed a PCR primer pair specific for the mbo operon to examine its distribution within the P. syringae complex. These primers amplified a 692-bp DNA fragment from 52 mangotoxin-producing strains and from 7 non-mangotoxin-producing strains that harbor the mbo operon, whereas 35 non-mangotoxin-producing strains did not yield any amplification. This, together with the analysis of draft genomes, allowed the identification of the mbo operon in five pathovars (pathovars aptata, avellanae, japonica, pisi, and syringae), all of which belong to genomospecies 1, suggesting a limited distribution of the mbo genes in the P. syringae complex. Phylogenetic analyses using partial sequences from housekeeping genes differentiated three groups within genomospecies 1. All of the strains containing the mbo operon clustered in groups I and II, whereas those lacking the operon clustered in group III; however, the relative branching order of these three groups is dependent on the genes used to construct the phylogeny. The mbo operon maintains synteny and is inserted in the same genomic location, with high sequence conservation around the insertion point, for all the strains in groups I and II. These data support the idea that the mbo operon was acquired horizontally and only once by the ancestor of groups I and II from genomospecies 1 within the P. syringae complex.
Collapse
Affiliation(s)
- Víctor J. Carrión
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - José A. Gutiérrez-Barranquero
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Eva Arrebola
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSMUMA-CSIC), Estación Experimental La Mayora, Algarrobo-Costa, Málaga, Spain
| | - Leire Bardaji
- Laboratorio de Patología Vegetal, ETS Ingenieros Agrónomos, Universidad Pública de Navarra, Pamplona, Spain
| | - Juan C. Codina
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Antonio de Vicente
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Francisco M. Cazorla
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Departamento de Microbiología, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain
| | - Jesús Murillo
- Laboratorio de Patología Vegetal, ETS Ingenieros Agrónomos, Universidad Pública de Navarra, Pamplona, Spain
| |
Collapse
|
45
|
Abstract
Transcriptional activation or ‘rewiring’ of silent genes is an important, yet poorly understood, phenomenon in prokaryotic genomes. Anecdotal evidence coming from experimental evolution studies in bacterial systems has shown the promptness of adaptation upon appropriate selective pressure. In many cases, a partial or complete promoter is mobilized to silent genes from elsewhere in the genome. We term hereafter such recruited regulatory sequences as Putative Mobile Promoters (PMPs) and we hypothesize they have a large impact on rapid adaptation of novel or cryptic functions. Querying all publicly available prokaryotic genomes (1362) uncovered >4000 families of highly conserved PMPs (50 to 100 long with ≥80% nt identity) in 1043 genomes from 424 different genera. The genomes with the largest number of PMP families are Anabaena variabilis (28 families), Geobacter uraniireducens (27 families) and Cyanothece PCC7424 (25 families). Family size varied from 2 to 93 homologous promoters (in Desulfurivibrio alkaliphilus). Some PMPs are present in particular species, but some are conserved across distant genera. The identified PMPs represent a conservative dataset of very recent or conserved events of mobilization of non-coding DNA and thus they constitute evidence of an extensive reservoir of recyclable regulatory sequences for rapid transcriptional rewiring.
Collapse
Affiliation(s)
- Mariana Matus-Garcia
- Department of Agrotechnology and Food Sciences, Laboratory of Systems and Synthetic Biology, Wageningen University, 6703HB Wageningen, The Netherlands
| | | | | |
Collapse
|
46
|
Arnold R, Boonen K, Sun MG, Kim PM. Computational analysis of interactomes: current and future perspectives for bioinformatics approaches to model the host-pathogen interaction space. Methods 2012; 57:508-18. [PMID: 22750305 PMCID: PMC7128575 DOI: 10.1016/j.ymeth.2012.06.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Revised: 06/20/2012] [Accepted: 06/21/2012] [Indexed: 11/05/2022] Open
Abstract
Bacterial and viral pathogens affect their eukaryotic host partly by interacting with proteins of the host cell. Hence, to investigate infection from a systems' perspective we need to construct complete and accurate host-pathogen protein-protein interaction networks. Because of the paucity of available data and the cost associated with experimental approaches, any construction and analysis of such a network in the near future has to rely on computational predictions. Specifically, this challenge consists of a number of sub-problems: First, prediction of possible pathogen interactors (e.g. effector proteins) is necessary for bacteria and protozoa. Second, the prospective host binding partners have to be determined and finally, the impact on the host cell analyzed. This review gives an overview of current bioinformatics approaches to obtain and understand host-pathogen interactions. As an application example of the methods covered, we predict host-pathogen interactions of Salmonella and discuss the value of these predictions as a prospective for further research.
Collapse
Affiliation(s)
- Roland Arnold
- Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada M5S 3E1
| | - Kurt Boonen
- Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada M5S 3E1
| | - Mark G.F. Sun
- Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada M5S 3E1
| | - Philip M. Kim
- Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada M5S 3E1
- Banting and Best Department of Medical Research, University of Toronto, Toronto, ON, Canada M5S 3E1
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 3E1
- Department of Computer Science, University of Toronto, Toronto, ON, Canada M5S 3E1
| |
Collapse
|
47
|
Host specificity determinants as a genetic continuum. Trends Microbiol 2011; 20:88-93. [PMID: 22196375 DOI: 10.1016/j.tim.2011.11.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 11/10/2011] [Accepted: 11/15/2011] [Indexed: 01/22/2023]
Abstract
Host specificity is an important concept that underlies the interaction of all clinically and agriculturally relevant microbes with their hosts. Changes in the host specificity of animal pathogens, in particular, are often of greatest concern due to their immediate and unexpected impact on human health. Host switching or host jumps can often be traced to modification of key microbial pathogenicity factors that facilitate the formation of particular host associations. An increase in the number of genome-level studies has begun revealing that almost any type of change, from the simplest to the most complex, can potentially impact host specificity. This review highlights examples of host specificity determinants of viruses, bacteria and fungi, and presents them from within a genetic continuum that spans from the single residue through to entire genomic islands.
Collapse
|
48
|
Abstract
Miniature inverted terminal repeat elements (MITEs) are nonautonomous mobile elements that have a significant impact on bacterial evolution. Here we characterize E622, a 611-bp virulence-associated MITE from Pseudomonas syringae, which contains no coding region but has almost perfect 168-bp inverted repeats. Using an antibiotic coupling assay, we show that E622 is transposable and can mobilize an antibiotic resistance gene contained between its borders. Its predicted parent element, designated TnE622, has a typical transposon structure with a three-gene operon, consisting of resolvase, integrase, and exeA-like genes, which is bounded by the same terminal inverted repeats as E622. A broader genome level survey of the E622/TnE622 inverted repeats identified homologs in Pseudomonas, Salmonella, Shewanella, Erwinia, Pantoea, and the cyanobacteria Nostoc and Cyanothece, many of which appear to encompass known virulence genes, including genes encoding toxins, enzymes, and type III secreted effectors. Its association with niche-specific genetic determinants, along with its persistence and evolutionary diversification, indicates that this mobile element family has played a prominent role in the evolution of many agriculturally and clinically relevant pathogenic bacteria.
Collapse
|
49
|
Burdman S, Bahar O, Parker JK, De La Fuente L. Involvement of Type IV Pili in Pathogenicity of Plant Pathogenic Bacteria. Genes (Basel) 2011; 2:706-35. [PMID: 24710288 PMCID: PMC3927602 DOI: 10.3390/genes2040706] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Revised: 10/08/2011] [Accepted: 10/10/2011] [Indexed: 01/03/2023] Open
Abstract
Type IV pili (T4P) are hair-like appendages found on the surface of a wide range of bacteria belonging to the β-, γ-, and δ-Proteobacteria, Cyanobacteria and Firmicutes. They constitute an efficient device for a particular type of bacterial surface motility, named twitching, and are involved in several other bacterial activities and functions, including surface adherence, colonization, biofilm formation, genetic material uptake and virulence. Tens of genes are involved in T4P synthesis and regulation, with the majority of them being generally named pil/fim genes. Despite the multiple functionality of T4P and their well-established role in pathogenicity of animal pathogenic bacteria, relatively little attention has been given to the role of T4P in plant pathogenic bacteria. Only in recent years studies have begun to examine with more attention the relevance of these surface appendages for virulence of plant bacterial pathogens. The aim of this review is to summarize the current knowledge about T4P genetic machinery and its role in the interactions between phytopathogenic bacteria and their plant hosts.
Collapse
Affiliation(s)
- Saul Burdman
- Department of Plant Pathology and Microbiology and the Otto Warburg Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
| | - Ofir Bahar
- Department of Plant Pathology and Microbiology and the Otto Warburg Center for Agricultural Biotechnology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot 76100, Israel.
| | - Jennifer K Parker
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA.
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL 36849, USA.
| |
Collapse
|
50
|
Bardaji L, Pérez-Martínez I, Rodríguez-Moreno L, Rodríguez-Palenzuela P, Sundin GW, Ramos C, Murillo J. Sequence and role in virulence of the three plasmid complement of the model tumor-inducing bacterium Pseudomonas savastanoi pv. savastanoi NCPPB 3335. PLoS One 2011; 6:e25705. [PMID: 22022435 PMCID: PMC3191145 DOI: 10.1371/journal.pone.0025705] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 09/08/2011] [Indexed: 12/18/2022] Open
Abstract
Pseudomonas savastanoi pv. savastanoi NCPPB 3335 is a model for the study of the molecular basis of disease production and tumor formation in woody hosts, and its draft genome sequence has been recently obtained. Here we closed the sequence of the plasmid complement of this strain, composed of three circular molecules of 78,357 nt (pPsv48A), 45,220 nt (pPsv48B), and 42,103 nt (pPsv48C), all belonging to the pPT23A-like family of plasmids widely distributed in the P. syringae complex. A total of 152 coding sequences were predicted in the plasmid complement, of which 38 are hypothetical proteins and seven correspond to putative virulence genes. Plasmid pPsv48A contains an incomplete Type IVB secretion system, the type III secretion system (T3SS) effector gene hopAF1, gene ptz, involved in cytokinin biosynthesis, and three copies of a gene highly conserved in plant-associated proteobacteria, which is preceded by a hrp box motif. A complete Type IVA secretion system, a well conserved origin of transfer (oriT), and a homolog of the T3SS effector gene hopAO1 are present in pPsv48B, while pPsv48C contains a gene with significant homology to isopentenyl-diphosphate delta-isomerase, type 1. Several potential mobile elements were found on the three plasmids, including three types of MITE, a derivative of IS801, and a new transposon effector, ISPsy30. Although the replication regions of these three plasmids are phylogenetically closely related, their structure is diverse, suggesting that the plasmid architecture results from an active exchange of sequences. Artificial inoculations of olive plants with mutants cured of plasmids pPsv48A and pPsv48B showed that pPsv48A is necessary for full virulence and for the development of mature xylem vessels within the knots; we were unable to obtain mutants cured of pPsv48C, which contains five putative toxin-antitoxin genes.
Collapse
Affiliation(s)
- Leire Bardaji
- Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, Pamplona, Spain
| | - Isabel Pérez-Martínez
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Málaga, Spain
| | - Luis Rodríguez-Moreno
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Málaga, Spain
| | - Pablo Rodríguez-Palenzuela
- Centro de Biotecnología y Genómica de Plantas, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Campus de Montegancedo, Pozuelo de Alarcón, Madrid, Spain
| | - George W. Sundin
- Department of Plant Pathology and Center for Microbial Ecology, Michigan State University, East Lansing, Michigan, United States of America
| | - Cayo Ramos
- Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Málaga, Spain
| | - Jesús Murillo
- Departamento de Producción Agraria, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Pública de Navarra, Pamplona, Spain
- * E-mail:
| |
Collapse
|