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Hu Y, Wang Y, Hu X, Chao H, Li S, Ni Q, Zhu Y, Hu Y, Zhao Z, Chen M. T4SEpp: A pipeline integrating protein language models to predict bacterial type IV secreted effectors. Comput Struct Biotechnol J 2024; 23:801-812. [PMID: 38328004 PMCID: PMC10847861 DOI: 10.1016/j.csbj.2024.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 01/20/2024] [Accepted: 01/20/2024] [Indexed: 02/09/2024] Open
Abstract
Many pathogenic bacteria use type IV secretion systems (T4SSs) to deliver effectors (T4SEs) into the cytoplasm of eukaryotic cells, causing diseases. The identification of effectors is a crucial step in understanding the mechanisms of bacterial pathogenicity, but this remains a major challenge. In this study, we used the full-length embedding features generated by six pre-trained protein language models to train classifiers predicting T4SEs and compared their performance. We integrated three modules into a model called T4SEpp. The first module searched for full-length homologs of known T4SEs, signal sequences, and effector domains; the second module fine-tuned a machine learning model using data for a signal sequence feature; and the third module used the three best-performing pre-trained protein language models. T4SEpp outperformed other state-of-the-art (SOTA) software tools, achieving ∼0.98 accuracy at a high specificity of ∼0.99, based on the assessment of an independent validation dataset. T4SEpp predicted 13 T4SEs from Helicobacter pylori, including the well-known CagA and 12 other potential ones, among which eleven could potentially interact with human proteins. This suggests that these potential T4SEs may be associated with the pathogenicity of H. pylori. Overall, T4SEpp provides a better solution to assist in the identification of bacterial T4SEs and facilitates studies of bacterial pathogenicity. T4SEpp is freely accessible at https://bis.zju.edu.cn/T4SEpp.
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Affiliation(s)
- Yueming Hu
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yejun Wang
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen, China
- Department of Cell Biology and Genetics, College of Basic Medicine, Shenzhen University Medical School, Shenzhen, China
| | - Xiaotian Hu
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Haoyu Chao
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Sida Li
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Qinyang Ni
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yanyan Zhu
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yixue Hu
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen, China
| | - Ziyi Zhao
- Youth Innovation Team of Medical Bioinformatics, Shenzhen University Medical School, Shenzhen, China
| | - Ming Chen
- Department of Bioinformatics, College of Life Sciences, Zhejiang University, Hangzhou, China
- Institute of Hematology, Zhejiang University School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou 310058, China
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2
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Li C, Fu J, Shao S, Luo ZQ. Legionella pneumophila exploits the endo-lysosomal network for phagosome biogenesis by co-opting SUMOylated Rab7. PLoS Pathog 2024; 20:e1011783. [PMID: 38739652 PMCID: PMC11115209 DOI: 10.1371/journal.ppat.1011783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 05/23/2024] [Accepted: 04/30/2024] [Indexed: 05/16/2024] Open
Abstract
Legionella pneumophila strains harboring wild-type rpsL such as Lp02rpsLWT cannot replicate in mouse bone marrow-derived macrophages (BMDMs) due to induction of extensive lysosome damage and apoptosis. The bacterial factor directly responsible for inducing such cell death and the host factor involved in initiating the signaling cascade that leads to lysosome damage remain unknown. Similarly, host factors that may alleviate cell death induced by these bacterial strains have not yet been investigated. Using a genome-wide CRISPR/Cas9 screening, we identified Hmg20a and Nol9 as host factors important for restricting strain Lp02rpsLWT in BMDMs. Depletion of Hmg20a protects macrophages from infection-induced lysosomal damage and apoptosis, allowing productive bacterial replication. The restriction imposed by Hmg20a was mediated by repressing the expression of several endo-lysosomal proteins, including the small GTPase Rab7. We found that SUMOylated Rab7 is recruited to the bacterial phagosome via SulF, a Dot/Icm effector that harbors a SUMO-interacting motif (SIM). Moreover, overexpression of Rab7 rescues intracellular growth of strain Lp02rpsLWT in BMDMs. Our results establish that L. pneumophila exploits the lysosomal network for the biogenesis of its phagosome in BMDMs.
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Affiliation(s)
- Chuang Li
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Jiaqi Fu
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
| | - Shuai Shao
- College of Pharmacy, The Ohio State University, Columbus, Ohio, United States of America
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, Ohio, United States of America
| | - Zhao-Qing Luo
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
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Kotewicz KM, Zhang M, Kim S, Martin MS, Chowdhury AR, Tai A, Scheck RA, Isberg RR. Sde Proteins Coordinate Ubiquitin Utilization and Phosphoribosylation to Promote Establishment and Maintenance of the Legionella Replication Vacuole. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.07.553534. [PMID: 38645023 PMCID: PMC11030226 DOI: 10.1101/2023.09.07.553534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The Legionella pneumophila Sde family of translocated proteins promotes host tubular endoplasmic reticulum (ER) rearrangements that are tightly linked to phosphoribosyl-ubiquitin (pR-Ub) modification of Reticulon 4 (Rtn4). Sde proteins have two additional activities of unclear relevance to the infection process: K63 linkage-specific deubiquitination and phosphoribosyl modification of polyubiquitin (pR-Ub). We show here that the deubiquitination activity (DUB) stimulates ER rearrangements while pR-Ub protects the replication vacuole from cytosolic surveillance by autophagy. Loss of DUB activity was tightly linked to lowered pR-Ub modification of Rtn4, consistent with the DUB activity fueling the production of pR-Ub-Rtn4. In parallel, phosphoribosyl modification of polyUb, in a region of the protein known as the isoleucine patch, prevented binding by the autophagy adapter p62. An inability of Sde mutants to modify polyUb resulted in immediate p62 association, a critical precursor to autophagic attack. The ability of Sde WT to block p62 association decayed quickly after bacterial infection, as predicted by the presence of previously characterized L. pneumophila effectors that inactivate Sde and remove polyUb. In sum, these results show that the accessory Sde activities act to stimulate ER rearrangements and protect from host innate immune sensing in a temporal fashion.
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Affiliation(s)
- Kristin M Kotewicz
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
- Current address: Gastrointestinal Unit and Center for the Study of Inflammatory Bowel Disease, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114
| | - Mengyun Zhang
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
- Current address: Global Health Drug Discovery Institute, Haidian, Beijing, China
| | - Seongok Kim
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
| | - Meghan S Martin
- Department of Chemistry, Tufts University, 62 Talbot Ave, Medford, MA, 02155, USA
| | - Atish Roy Chowdhury
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
| | - Albert Tai
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
| | - Rebecca A Scheck
- Department of Chemistry, Tufts University, 62 Talbot Ave, Medford, MA, 02155, USA
| | - Ralph R Isberg
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
- Department of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, 150 Harrison Ave., Boston, MA 02111, USA
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Hershkovitz D, Chen EJ, Ensminger AW, Dugan AS, Joyce AC, Segal G, Isberg RR. Genetic evidence for a regulated cysteine protease catalytic triad in LegA7, a Legionella pneumophila protein that impinges on a stress response pathway. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.17.585421. [PMID: 38562771 PMCID: PMC10983931 DOI: 10.1101/2024.03.17.585421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Legionella pneumophila grows within membrane-bound vacuoles in phylogenetically diverse hosts. Intracellular growth requires the function of the Icm/Dot type-IVb secretion system, which translocates more than 300 proteins into host cells. A screen was performed to identify L. pneumophila proteins that stimulate MAPK activation, using Icm/Dot translocated proteins ectopically expressed in mammalian cells. In parallel, a second screen was performed to identify L. pneumophila proteins expressed in yeast that cause growth inhibition in MAPK pathway-stimulatory high osmolarity medium. LegA7 was shared in both screens, a protein predicted to be a member of the bacterial cysteine protease family that has five carboxyl-terminal ankyrin repeats. Three conserved residues in the predicted catalytic triad of LegA7 were mutated. These mutations abolished the ability of LegA7 to inhibit yeast growth. To identify other residues important for LegA7 function, a generalizable selection strategy in yeast was devised to isolate mutants that have lost function and no longer cause growth inhibition on high osmolarity medium. Mutations were isolated in the two amino-terminal ankyrin repeats, as well as an inter-domain region located between the cysteine protease domain and the ankyrin repeats. These mutations were predicted by AlphaFold modeling to localize to the face opposite from the catalytic site, arguing that they interfere with the positive regulation of the catalytic activity. Based on our data, we present a model in which LegA7 harbors a cysteine protease domain with an inter-domain and two amino-terminal ankyrin repeat regions that modulate the function of the catalytic domain.
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Affiliation(s)
- Dar Hershkovitz
- The Shmunis School of Biomedicine and Cancer Research George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 6997801, Israel
| | - Emy J. Chen
- Department of Molecular Biology and Microbiology
- Program in Genetics, Graduate School of Biomedical Science Tufts University School of Medicine,150 Harrison Ave., Boston, MA 02115, USA
| | | | - Aisling S. Dugan
- Department of Molecular Biology and Microbiology
- Current Address: Dept. of Biology, Brown University, Providence, RI 02912
| | | | - Gil Segal
- The Shmunis School of Biomedicine and Cancer Research George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, 6997801, Israel
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Zhang Z, Fu J, Rack JGM, Li C, Voorneveld J, Filippov DV, Ahel I, Luo ZQ, Das C. Legionella metaeffector MavL reverses ubiquitin ADP-ribosylation via a conserved arginine-specific macrodomain. Nat Commun 2024; 15:2452. [PMID: 38503748 PMCID: PMC10951314 DOI: 10.1038/s41467-024-46649-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 02/26/2024] [Indexed: 03/21/2024] Open
Abstract
ADP-ribosylation is a reversible post-translational modification involved in various cellular activities. Removal of ADP-ribosylation requires (ADP-ribosyl)hydrolases, with macrodomain enzymes being a major family in this category. The pathogen Legionella pneumophila mediates atypical ubiquitination of host targets using the SidE effector family in a process that involves ubiquitin ADP-ribosylation on arginine 42 as an obligatory step. Here, we show that the Legionella macrodomain effector MavL regulates this pathway by reversing the arginine ADP-ribosylation, likely to minimize potential detrimental effects caused by the modified ubiquitin. We determine the crystal structure of ADP-ribose-bound MavL, providing structural insights into recognition of the ADP-ribosyl group and catalytic mechanism of its removal. Further analyses reveal DUF4804 as a class of MavL-like macrodomain enzymes whose representative members show unique selectivity for mono-ADP-ribosylated arginine residue in synthetic substrates. We find such enzymes are also present in eukaryotes, as exemplified by two previously uncharacterized (ADP-ribosyl)hydrolases in Drosophila melanogaster. Crystal structures of several proteins in this class provide insights into arginine specificity and a shared mode of ADP-ribose interaction distinct from previously characterized macrodomains. Collectively, our study reveals a new regulatory layer of SidE-catalyzed ubiquitination and expands the current understanding of macrodomain enzymes.
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Affiliation(s)
- Zhengrui Zhang
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA
| | - Jiaqi Fu
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, 47907, USA
| | - Johannes Gregor Matthias Rack
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE, Oxford, UK
- MRC Centre for Medical Mycology, University of Exeter, Geoffrey Pope Building, Stocker Road, EX4 4QD, Exeter, UK
| | - Chuang Li
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, 47907, USA
| | - Jim Voorneveld
- Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, 2300 RA, Leiden, The Netherlands
| | - Dmitri V Filippov
- Bio-Organic Synthesis, Leiden Institute of Chemistry, Leiden University, 2300 RA, Leiden, The Netherlands
| | - Ivan Ahel
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, OX1 3RE, Oxford, UK
| | - Zhao-Qing Luo
- Department of Biological Sciences, Purdue Institute for Inflammation, Immunology and Infectious Disease, Purdue University, West Lafayette, IN, 47907, USA
| | - Chittaranjan Das
- Department of Chemistry, Purdue University, West Lafayette, IN, 47907, USA.
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6
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Syriste L, Patel DT, Stogios PJ, Skarina T, Patel D, Savchenko A. An acetyltransferase effector conserved across Legionella species targets the eukaryotic eIF3 complex to modulate protein translation. mBio 2024; 15:e0322123. [PMID: 38335095 PMCID: PMC10936415 DOI: 10.1128/mbio.03221-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/16/2024] [Indexed: 02/12/2024] Open
Abstract
The survival of Legionella spp. as intracellular pathogens relies on the combined action of protein effectors delivered inside their eukaryotic hosts by the Dot/Icm (defective in organelle trafficking/intracellular multiplication) type IVb secretion system. The specific repertoire of effector arsenals varies dramatically across over 60 known species of this genera with Legionella pneumophila responsible for most cases of Legionnaires' disease in humans encoding over 360 Dot/Icm effectors. However, a small subset of "core" effectors appears to be conserved across all Legionella species raising an intriguing question of their role in these bacteria's pathogenic strategy, which for most of these effectors remains unknown. L. pneumophila Lpg0103 effector, also known as VipF, represents one of the core effector families that features a tandem of Gcn5-related N-acetyltransferase (GNAT) domains. Here, we present the crystal structure of the Lha0223, the VipF representative from Legionella hackeliae in complex with acetyl-coenzyme A determined to 1.75 Å resolution. Our structural analysis suggested that this effector family shares a common fold with the two GNAT domains forming a deep groove occupied by residues conserved across VipF homologs. Further analysis suggested that only the C-terminal GNAT domain of VipF effectors retains the active site composition compatible with catalysis, whereas the N-terminal GNAT domain binds the ligand in a non-catalytical mode. We confirmed this by in vitro enzymatic assays which revealed VipF activity not only against generic small molecule substrates, such as chloramphenicol, but also against poly-L-lysine and histone-derived peptides. We identified the human eukaryotic translation initiation factor 3 (eIF3) complex co-precipitating with Lpg0103 and demonstrated the direct interaction between the several representatives of the VipF family, including Lpg0103 and Lha0223 with the K subunit of eIF3. According to our data, these interactions involve primarily the C-terminal tail of eIF3-K containing two lysine residues that are acetylated by VipF. VipF catalytic activity results in the suppression of eukaryotic protein translation in vitro, revealing the potential function of VipF "core" effectors in Legionella's pathogenic strategy.IMPORTANCEBy translocating effectors inside the eukaryotic host cell, bacteria can modulate host cellular processes in their favor. Legionella species, which includes the pneumonia-causing Legionella pneumophila, encode a widely diverse set of effectors with only a small subset that is conserved across this genus. Here, we demonstrate that one of these conserved effector families, represented by L. pneumophila VipF (Lpg0103), is a tandem Gcn5-related N-acetyltransferase interacting with the K subunit of human eukaryotic initiation factor 3 complex. VipF catalyzes the acetylation of lysine residues on the C-terminal tail of the K subunit, resulting in the suppression of eukaryotic translation initiation factor 3-mediated protein translation in vitro. These new data provide the first insight into the molecular function of this pathogenic factor family common across Legionellae.
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Affiliation(s)
- Lukas Syriste
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Deepak T. Patel
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Peter J. Stogios
- Department of Chemical Engineering and Applied Chemistry, Toronto University, Toronto, Ontario, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, Toronto University, Toronto, Ontario, Canada
| | - Dhruvin Patel
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
| | - Alexei Savchenko
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Department of Chemical Engineering and Applied Chemistry, Toronto University, Toronto, Ontario, Canada
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Hiller M, Diwo M, Wamp S, Gutsmann T, Lang C, Blankenfeldt W, Flieger A. Structure-function relationships underpin disulfide loop cleavage-dependent activation of Legionella pneumophila lysophospholipase A PlaA. Mol Microbiol 2024; 121:497-512. [PMID: 38130174 DOI: 10.1111/mmi.15201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 11/03/2023] [Indexed: 12/23/2023]
Abstract
Legionella pneumophila, the causative agent of a life-threatening pneumonia, intracellularly replicates in a specialized compartment in lung macrophages, the Legionella-containing vacuole (LCV). Secreted proteins of the pathogen govern important steps in the intracellular life cycle including bacterial egress. Among these is the type II secreted PlaA which, together with PlaC and PlaD, belongs to the GDSL phospholipase family found in L. pneumophila. PlaA shows lysophospholipase A (LPLA) activity which increases after secretion and subsequent processing by the zinc metalloproteinase ProA within a disulfide loop. Activity of PlaA contributes to the destabilization of the LCV in the absence of the type IVB-secreted effector SdhA. We here present the 3D structure of PlaA which shows a typical α/β-hydrolase fold and reveals that the uncleaved disulfide loop forms a lid structure covering the catalytic triad S30/D278/H282. This leads to reduction of substrate access before activation; however, the catalytic site gets more accessible when the disulfide loop is processed. After structural modeling, a similar activation process is suggested for the GDSL hydrolase PlaC, but not for PlaD. Furthermore, the size of the PlaA substrate-binding site indicated preference toward phospholipids comprising ~16 carbon fatty acid residues which was verified by lipid hydrolysis, suggesting a molecular ruler mechanism. Indeed, mutational analysis changed the substrate profile with respect to fatty acid chain length. In conclusion, our analysis revealed the structural basis for the regulated activation and substrate preference of PlaA.
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Affiliation(s)
- Miriam Hiller
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
| | - Maurice Diwo
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Sabrina Wamp
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
| | - Thomas Gutsmann
- Research Center Borstel, Leibniz Lung Center, Division of Biophysics, Borstel, Germany
- CSSB-Centre for Structural Systems Biology, Hamburg, Germany
| | - Christina Lang
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
| | - Wulf Blankenfeldt
- Structure and Function of Proteins, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Braunschweig, Germany
| | - Antje Flieger
- Division of Enteropathogenic Bacteria and Legionella (FG11), Robert Koch Institute, Wernigerode, Germany
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8
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Graham CI, MacMartin TL, de Kievit TR, Brassinga AKC. Molecular regulation of virulence in Legionella pneumophila. Mol Microbiol 2024; 121:167-195. [PMID: 37908155 DOI: 10.1111/mmi.15172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/15/2023] [Accepted: 09/17/2023] [Indexed: 11/02/2023]
Abstract
Legionella pneumophila is a gram-negative bacteria found in natural and anthropogenic aquatic environments such as evaporative cooling towers, where it reproduces as an intracellular parasite of cohabiting protozoa. If L. pneumophila is aerosolized and inhaled by a susceptible person, bacteria may colonize their alveolar macrophages causing the opportunistic pneumonia Legionnaires' disease. L. pneumophila utilizes an elaborate regulatory network to control virulence processes such as the Dot/Icm Type IV secretion system and effector repertoire, responding to changing nutritional cues as their host becomes depleted. The bacteria subsequently differentiate to a transmissive state that can survive in the environment until a replacement host is encountered and colonized. In this review, we discuss the lifecycle of L. pneumophila and the molecular regulatory network that senses nutritional depletion via the stringent response, a link to stationary phase-like metabolic changes via alternative sigma factors, and two-component systems that are homologous to stress sensors in other pathogens, to regulate differentiation between the intracellular replicative phase and more transmissible states. Together, we highlight how this prototypic intracellular pathogen offers enormous potential in understanding how molecular mechanisms enable intracellular parasitism and pathogenicity.
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Affiliation(s)
- Christopher I Graham
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Teassa L MacMartin
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Teresa R de Kievit
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Ann Karen C Brassinga
- Department of Microbiology, Faculty of Science, University of Manitoba, Winnipeg, Manitoba, Canada
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9
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Shapira N, Zusman T, Segal G. The LysR-type transcriptional regulator LelA co-regulates various effectors in different Legionella species. Mol Microbiol 2024; 121:243-259. [PMID: 38153189 DOI: 10.1111/mmi.15214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/05/2023] [Accepted: 12/08/2023] [Indexed: 12/29/2023]
Abstract
The intracellular pathogen Legionella pneumophila translocates more than 300 effector proteins into its host cells. The expression levels of the genes encoding these effectors are orchestrated by an intricate regulatory network. Here, we introduce LelA, the first L. pneumophila LysR-type transcriptional regulator of effectors. Through bioinformatic and experimental analyses, we identified the LelA target regulatory element and demonstrated that it directly activates the expression of three L. pneumophila effectors (legL7, legL6, and legU1). We further found that the gene encoding LelA is positively regulated by the RpoS sigma factor, thus linking it to the known effector regulatory network. Examination of other species throughout the Legionella genus revealed that this regulatory element is found upstream of 34 genes encoding validated effectors, putative effectors, and hypothetical proteins. Moreover, ten of these genes were examined and found to be activated by the L. pneumophila LelA as well as by their orthologs in the corresponding species. LelA represents a novel type of Legionella effector regulator, which coordinates the expression of both adjacently and distantly located effector-encoding genes, thus forming small groups of co-regulated effectors.
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Affiliation(s)
- Naomi Shapira
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Tal Zusman
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
| | - Gil Segal
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel-Aviv, Israel
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10
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Ellis NA, Myers KS, Tung J, Davidson Ward A, Johnston K, Bonnington KE, Donohue TJ, Machner MP. A randomized multiplex CRISPRi-Seq approach for the identification of critical combinations of genes. eLife 2023; 12:RP86903. [PMID: 38095310 PMCID: PMC10721215 DOI: 10.7554/elife.86903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2023] Open
Abstract
Identifying virulence-critical genes from pathogens is often limited by functional redundancy. To rapidly interrogate the contributions of combinations of genes to a biological outcome, we have developed a multiplex, randomized CRISPR interference sequencing (MuRCiS) approach. At its center is a new method for the randomized self-assembly of CRISPR arrays from synthetic oligonucleotide pairs. When paired with PacBio long-read sequencing, MuRCiS allowed for near-comprehensive interrogation of all pairwise combinations of a group of 44 Legionella pneumophila virulence genes encoding highly conserved transmembrane proteins for their role in pathogenesis. Both amoeba and human macrophages were challenged with L. pneumophila bearing the pooled CRISPR array libraries, leading to the identification of several new virulence-critical combinations of genes. lpg2888 and lpg3000 were particularly fascinating for their apparent redundant functions during L. pneumophila human macrophage infection, while lpg3000 alone was essential for L. pneumophila virulence in the amoeban host Acanthamoeba castellanii. Thus, MuRCiS provides a method for rapid genetic examination of even large groups of redundant genes, setting the stage for application of this technology to a variety of biological contexts and organisms.
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Affiliation(s)
- Nicole A Ellis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Kevin S Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-MadisonMadisonUnited States
- Wisconsin Energy Institute, University of Wisconsin-MadisonMadisonUnited States
| | - Jessica Tung
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Anne Davidson Ward
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Kathryn Johnston
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Katherine E Bonnington
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
| | - Timothy J Donohue
- Great Lakes Bioenergy Research Center, University of Wisconsin-MadisonMadisonUnited States
- Wisconsin Energy Institute, University of Wisconsin-MadisonMadisonUnited States
- Department of Bacteriology, University of Wisconsin-MadisonMadisonUnited States
| | - Matthias P Machner
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of HealthBethesdaUnited States
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Sanderlin AG, Margolis HK, Meyer AF, Lamason RL. Cell-selective proteomics reveal novel effectors secreted by an obligate intracellular bacterial pathogen. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567466. [PMID: 38014272 PMCID: PMC10680844 DOI: 10.1101/2023.11.17.567466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Pathogenic bacteria secrete protein effectors to hijack host machinery and remodel their infectious niche. Rickettsia spp. are obligate intracellular bacteria that can cause life-threatening disease, but their absolute dependence on the host cell environment has impeded discovery of rickettsial effectors and their host targets. We implemented bioorthogonal non-canonical amino acid tagging (BONCAT) during R. parkeri infection to selectively label, isolate, and identify secreted effectors. As the first use of BONCAT in an obligate intracellular bacterium, our screen more than doubles the number of experimentally validated effectors for R. parkeri. The novel secreted rickettsial factors (Srfs) we identified include Rickettsia-specific proteins of unknown function that localize to the host cytoplasm, mitochondria, and ER. We further show that one such effector, SrfD, interacts with the host Sec61 translocon. Altogether, our work uncovers a diverse set of previously uncharacterized rickettsial effectors and lays the foundation for a deeper exploration of the host-pathogen interface.
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Affiliation(s)
- Allen G. Sanderlin
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Hannah K. Margolis
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Abigail F. Meyer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Rebecca L. Lamason
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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12
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Ellis NA, Myers KS, Tung J, Ward AD, Johnston K, Bonnington KE, Donohue TJ, Machner MP. A randomized multiplex CRISPRi-Seq approach for the identification of critical combinations of genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.03.527066. [PMID: 36945652 PMCID: PMC10028747 DOI: 10.1101/2023.02.03.527066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Identifying virulence-critical genes from pathogens is often limited by functional redundancy. To rapidly interrogate the contributions of combinations of genes to a biological outcome, we have developed a multiplex, randomized CRISPR interference sequencing (MuRCiS) approach. At its center is a new method for the randomized self-assembly of CRISPR arrays from synthetic oligonucleotide pairs. When paired with PacBio long-read sequencing, MuRCiS allowed for near-comprehensive interrogation of all pairwise combinations of a group of 44 Legionella pneumophila virulence genes encoding highly conserved transmembrane proteins for their role in pathogenesis. Both amoeba and human macrophages were challenged with L. pneumophila bearing the pooled CRISPR array libraries, leading to the identification of several new virulence-critical combinations of genes. lpg2888 and lpg3000 were particularly fascinating for their apparent redundant functions during L. pneumophila human macrophage infection, while lpg3000 alone was essential for L. pneumophila virulence in the amoeban host Acanthamoeba castellanii. Thus, MuRCiS provides a method for rapid genetic examination of even large groups of redundant genes, setting the stage for application of this technology to a variety of biological contexts and organisms.
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Affiliation(s)
- Nicole A. Ellis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Kevin S. Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Jessica Tung
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Anne Davidson Ward
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Kathryn Johnston
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Katherine E. Bonnington
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Timothy J. Donohue
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Matthias P. Machner
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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13
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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: 0] [Impact Index Per Article: 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.
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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.
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14
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Li C, Fu J, Shao S, Luo ZQ. Legionella pneumophila exploits the endo-lysosomal network for phagosome biogenesis by co-opting SUMOylated Rab7. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.31.564884. [PMID: 37961430 PMCID: PMC10634985 DOI: 10.1101/2023.10.31.564884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
L. pneumophila strains harboring wild-type rpsL such as Lp02rpsLWT cannot replicate in mouse bone marrow-derived macrophages (BMDMs) due to induction of extensive lysosome damage and apoptosis. The mechanism of this unique infection-induced cell death remains unknown. Using a genome-wide CRISPR/Cas9 screening, we identified Hmg20a and Nol9 as host factors important for restricting strain Lp02rpsLWT in BMDMs. Depletion of Hmg20a protects macrophages from infection-induced lysosomal damage and apoptosis, allowing productive bacterial replication. The restriction imposed by Hmg20a was mediated by repressing the expression of several endo-lysosomal proteins, including the small GTPase Rab7. We found that SUMOylated Rab7 is recruited to the bacterial phagosome via SulF, a Dot/Icm effector that harbors a SUMO-interacting motif (SIM). Moreover, overexpression of Rab7 rescues intracellular growth of strain Lp02rpsLWT in BMDMs. Our results establish that L. pneumophila exploits the lysosomal network for the biogenesis of its phagosome in BMDMs.
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Affiliation(s)
- Chuang Li
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, IN 47906, USA
| | - Jiaqi Fu
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, IN 47906, USA
| | - Shuai Shao
- College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA
- Department of Biomedical Informatics, College of Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Zhao-Qing Luo
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, IN 47906, USA
- Lead Contact
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15
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Rolando M, Wah Chung IY, Xu C, Gomez-Valero L, England P, Cygler M, Buchrieser C. The SET and ankyrin domains of the secreted Legionella pneumophila histone methyltransferase work together to modify host chromatin. mBio 2023; 14:e0165523. [PMID: 37795993 PMCID: PMC10653858 DOI: 10.1128/mbio.01655-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/22/2023] [Indexed: 10/06/2023] Open
Abstract
IMPORTANCE Legionella pneumophila is an intracellular bacterium responsible of Legionnaires' disease, a severe pneumonia that is often fatal when not treated promptly. The pathogen's ability to efficiently colonize the host resides in its ability to replicate intracellularly. Essential for intracellular replication is translocation of many different protein effectors via a specialized secretion system. One of them, called RomA, binds and directly modifies the host chromatin at a unique site (tri-methylation of lysine 14 of histone H3 [H3K14me]). However, the molecular mechanisms of binding are not known. Here, we resolve this question through structural characterization of RomA together with the H3 peptide. We specifically reveal an active role of the ankyrin repeats located in its C-terminal in the interaction with the histone H3 tail. Indeed, without the ankyrin domains, RomA loses its ability to act as histone methyltransferase. These results discover the molecular mechanisms by which a bacterial histone methyltransferase that is conserved in L. pneumophila strains acts to modify chromatin.
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Affiliation(s)
- Monica Rolando
- Institut Pasteur, Université de Paris, Biologie des Bactéries Intracellulaires, Paris, France
| | - Ivy Yeuk Wah Chung
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Caishuang Xu
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Laura Gomez-Valero
- Institut Pasteur, Université de Paris, Biologie des Bactéries Intracellulaires, Paris, France
| | - Patrick England
- Institut Pasteur, Université de Paris, Plateforme de Biophysique Moléculaire, Paris, France
| | - Miroslaw Cygler
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Carmen Buchrieser
- Institut Pasteur, Université de Paris, Biologie des Bactéries Intracellulaires, Paris, France
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16
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Lin JD, Stogios PJ, Abe KT, Wang A, MacPherson J, Skarina T, Gingras AC, Savchenko A, Ensminger AW. Functional diversification despite structural congruence in the HipBST toxin-antitoxin system of Legionella pneumophila. mBio 2023; 14:e0151023. [PMID: 37819088 PMCID: PMC10653801 DOI: 10.1128/mbio.01510-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 08/29/2023] [Indexed: 10/13/2023] Open
Abstract
IMPORTANCE Toxin-antitoxin (TA) systems are parasitic genetic elements found in almost all bacterial genomes. They are exchanged horizontally between cells and are typically poorly conserved across closely related strains and species. Here, we report the characterization of a tripartite TA system in the bacterial pathogen Legionella pneumophila that is highly conserved across Legionella species genomes. This system (denoted HipBSTLp) is a distant homolog of the recently discovered split-HipA system in Escherichia coli (HipBSTEc). We present bioinformatic, molecular, and structural analyses of the divergence between these two systems and the functionality of this newly described TA system family. Furthermore, we provide evidence to refute previous claims that the toxin in this system (HipTLp) possesses bifunctionality as an L. pneumophila virulence protein. Overall, this work expands our understanding of the split-HipA system architecture and illustrates the potential for undiscovered biology in these abundant genetic elements.
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Affiliation(s)
- Jordan D. Lin
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Peter J. Stogios
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Kento T. Abe
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, Ontario, Canada
| | - Avril Wang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - John MacPherson
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Tatiana Skarina
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Anne-Claude Gingras
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, Ontario, Canada
| | - Alexei Savchenko
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Alberta, Canada
- Center for Structural Genomics of Infectious Diseases (CSGID), University of Calgary, Calgary, Alberta, Canada
| | - Alexander W. Ensminger
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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17
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Zayed AR, Burghal M, Butmeh S, Samba-Louaka A, Steinert M, Bitar DM. Legionella pneumophila Presence in Dental Unit Waterlines: A Cultural and Molecular Investigation in the West Bank, Palestine. Trop Med Infect Dis 2023; 8:490. [PMID: 37999609 PMCID: PMC10675536 DOI: 10.3390/tropicalmed8110490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 10/15/2023] [Accepted: 10/25/2023] [Indexed: 11/25/2023] Open
Abstract
A Legionella pneumophila bacterium is ubiquitous in water distribution systems, including dental unit waterlines (DUWLs). Legionellosis is atypical pneumonia, including Legionnaires' disease (LD) and the less acute form of Pontiac fever. Legionellosis occurs as a result of inhalation/aspiration of aerosolized Legionella-contaminated water by susceptible patients, health workers, and dentists. In this study, we undertook to determine the prevalence of Legionella in water and biofilm samples from Tap and DUWLs collected from five sites of dental clinics and faculties across the West Bank. Water samples were tested for physical and chemical parameters. The study samples included 185 samples, 89 (48%) water samples, and 96 (52%) biofilm swabs, which were analyzed by cultivation-dependent analysis (CDA) and by the cultivation-independent technique (CIA). Also, partial sequencing of the 16S rRNA gene for fifteen L. pneumophila isolates was performed for quality assurance and identification. L. pneumophila was isolated from 28 (15%) of 185 samples using CDA and was detected in 142 (77%) of 185 samples using CIA. The abundance of culturable L. pneumophila was low in DUWL of the sampling sites (range: 27-115 CFU/Liter). PCR was 5× more sensitive than the culture technique. L. pneumophila Sg 1 was detected in (75%) of the isolates, while (25%) isolates were L. pneumophila Sg 2-14. All fifteen sequenced Legionella isolates were identified as L. pneumophila ≥ 94.5%. The analysis of phylogenetic tree showed that L. pneumophila branch clearly identified and distinguished from other branches. These results show that DUWLs of the examined dental clinics and faculties are contaminated with L. pneumophila. This finding reveals a serious potential health risk for infection of immunocompromised patients and dentists' post-exposure.
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Affiliation(s)
- Ashraf R. Zayed
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus P.O. Box 7, Palestine
| | - Mutasem Burghal
- Microbiology Research Laboratory, Faculty of Medicine, Al-Quds University, Abu-Dies, East Jerusalem P.O. Box 51000, Palestine; (M.B.); (S.B.)
| | - Suha Butmeh
- Microbiology Research Laboratory, Faculty of Medicine, Al-Quds University, Abu-Dies, East Jerusalem P.O. Box 51000, Palestine; (M.B.); (S.B.)
| | - Ascel Samba-Louaka
- Laboratoire Ecologie et Biologie des Interactions, Université de Poitiers, UMR CNRS 7267, 86000 Poitiers, France;
| | - Michael Steinert
- Institut für Mikrobiologie, Technische Universität Braunschweig, 38106 Braunschweig, Germany;
| | - Dina M. Bitar
- Microbiology Research Laboratory, Faculty of Medicine, Al-Quds University, Abu-Dies, East Jerusalem P.O. Box 51000, Palestine; (M.B.); (S.B.)
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18
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Isberg R, Kotewicz K, Zheng M, Kim S, Tai A. Sde Proteins Coordinate Ubiquitin Utilization and Phosphoribosylation to Promote Establishment and Maintenance of the Legionella Replication Vacuole. RESEARCH SQUARE 2023:rs.3.rs-3269310. [PMID: 37790456 PMCID: PMC10543313 DOI: 10.21203/rs.3.rs-3269310/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The Legionella pneumophilaSde family of translocated proteins promote host tubular endoplasmic reticulum (ER) rearrangements that are tightly linked to phosphoribosyl-ubiquitin (pR-Ub) modification of Reticulon 4 (Rtn4). Sde proteins have two additional activities of unclear relevance to the infection process: K63 linkage-specific deubiquitination and phosphoribosyl modification of polyubiquitin (pR-Ub). We show here that the deubiquitination activity (DUB) stimulates ER rearrangements while pR-Ub protects the replication vacuole from cytosolic surveillance by autophagy. Loss of DUB activity was tightly linked to lowered pR-Ub modification of Rtn4, consistent with the DUB activity fueling the production of pR-Ub-Rtn4. In parallel, phosphoribosyl modification of polyUb, in a region of the protein known as the isoleucine patch, caused an absolute block in binding by the autophagy adapter p62. An inability of Sde mutants to modify polyUb resulted in immediate p62 association, a critical precursor to autophagic attack. The ability of Sde WT to block p62 association decayed quickly after bacterial infection, as predicted by the presence of previously characterized L. pneumophila effectors that inactivate Sde and remove polyUb. In sum, these results show that the accessory Sde activities act to stimulate ER rearrangements and protect from host innate immune sensing in a temporal fashion.
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Wan M, Minelli ME, Zhao Q, Marshall S, Yu H, Smolka M, Mao Y. Phosphoribosyl modification of poly-ubiquitin chains at the Legionella-containing vacuole prohibiting autophagy adaptor recognition. RESEARCH SQUARE 2023:rs.3.rs-3266941. [PMID: 37790579 PMCID: PMC10543435 DOI: 10.21203/rs.3.rs-3266941/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Ubiquitination is a crucial posttranslational modification in eukaryotes that plays a significant role in the infection of intracellular microbial pathogens, such as Legionella pneumophila, the bacterium responsible for Legionnaires' disease. While the Legionella-containing vacuole (LCV) is coated with ubiquitin (Ub), it avoids recognition by autophagy adaptors. In this study, we report that the Sdc and Sde families of effectors work together to build ubiquitinated species around the LCV. The Sdc effectors catalyze canonical polyubiquitination directly on host targets or on the phosphoribosyl-Ub (PR-Ub) conjugated to host targets by Sde. Remarkably, the Ub moieties within the poly-Ub chains are either modified with a phosphoribosyl group by Sde and other PDE domain-containing effectors or covalently attached to other host substrates via Sde-mediated PR-ubiquitination. Furthermore, these modifications prevent the recognition by Ub adaptors, such as p62, and therefore exclude host autophagy adaptors from the LCV. Our findings shed light on the nature of the poly-ubiquitinated species present at the surface of the LCV and provide a molecular mechanism for the avoidance of autophagy adaptors by the Ub-decorated LCV.
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Affiliation(s)
- Min Wan
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Marena E. Minelli
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Qiuye Zhao
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Shannon Marshall
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Haiyuan Yu
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Computational Biology, Cornell University, Ithaca, NY 14853, USA
| | - Marcus Smolka
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
| | - Yuxin Mao
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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20
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Lopez AE, Grigoryeva LS, Barajas A, Cianciotto NP. Legionella pneumophila Rhizoferrin Promotes Bacterial Biofilm Formation and Growth within Amoebae and Macrophages. Infect Immun 2023; 91:e0007223. [PMID: 37428036 PMCID: PMC10429650 DOI: 10.1128/iai.00072-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 06/20/2023] [Indexed: 07/11/2023] Open
Abstract
Previously, we showed that Legionella pneumophila secretes rhizoferrin, a polycarboxylate siderophore that promotes bacterial growth in iron-deplete media and the murine lung. Yet, past studies failed to identify a role for the rhizoferrin biosynthetic gene (lbtA) in L. pneumophila infection of host cells, suggesting the siderophore's importance was solely linked to extracellular survival. To test the possibility that rhizoferrin's relevance to intracellular infection was missed due to functional redundancy with the ferrous iron transport (FeoB) pathway, we characterized a new mutant lacking both lbtA and feoB. This mutant was highly impaired for growth on bacteriological media that were only modestly depleted of iron, confirming that rhizoferrin-mediated ferric iron uptake and FeoB-mediated ferrous iron uptake are critical for iron acquisition. The lbtA feoB mutant, but not its lbtA-containing complement, was also highly defective for biofilm formation on plastic surfaces, demonstrating a new role for the L. pneumophila siderophore in extracellular survival. Finally, the lbtA feoB mutant, but not its complement containing lbtA, proved to be greatly impaired for growth in Acanthamoeba castellanii, Vermamoeba vermiformis, and human U937 cell macrophages, revealing that rhizoferrin does promote intracellular infection by L. pneumophila. Moreover, the application of purified rhizoferrin triggered cytokine production from the U937 cells. Rhizoferrin-associated genes were fully conserved across the many sequenced strains of L. pneumophila examined but were variably present among strains from the other species of Legionella. Outside of Legionella, the closest match to the L. pneumophila rhizoferrin genes was in Aquicella siphonis, another facultative intracellular parasite of amoebae.
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Affiliation(s)
- Alberto E. Lopez
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Lubov S. Grigoryeva
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Armando Barajas
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Nicholas P. Cianciotto
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
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21
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Lopez AE, Mayoral J, Cianciotto NP. Complete Genome Sequence of Legionella cardiaca Strain H63 T, Isolated from a Case of Native Valve Endocarditis. Microbiol Resour Announc 2023; 12:e0017523. [PMID: 37310280 PMCID: PMC10353460 DOI: 10.1128/mra.00175-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/30/2023] [Indexed: 06/14/2023] Open
Abstract
We report the complete genome sequence of Legionella cardiaca strain H63T, which had been isolated from aortic valve tissue from a patient with native endocarditis. The genome assembly contains a single 3,477,232-bp contig, with a G+C content of 38.59%, and is predicted to encode 2,948 proteins.
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Affiliation(s)
- Alberto E. Lopez
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Joshua Mayoral
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
| | - Nicholas P. Cianciotto
- Department of Microbiology and Immunology, Northwestern University Medical School, Chicago, Illinois, USA
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22
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Wagner N, Ben-Meir D, Teper D, Pupko T. Complete genome sequence of an Israeli isolate of Xanthomonas hortorum pv. pelargonii strain 305 and novel type III effectors identified in Xanthomonas. FRONTIERS IN PLANT SCIENCE 2023; 14:1155341. [PMID: 37332699 PMCID: PMC10275491 DOI: 10.3389/fpls.2023.1155341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/10/2023] [Indexed: 06/20/2023]
Abstract
Xanthomonas hortorum pv. pelargonii is the causative agent of bacterial blight in geranium ornamental plants, the most threatening bacterial disease of this plant worldwide. Xanthomonas fragariae is the causative agent of angular leaf spot in strawberries, where it poses a significant threat to the strawberry industry. Both pathogens rely on the type III secretion system and the translocation of effector proteins into the plant cells for their pathogenicity. Effectidor is a freely available web server we have previously developed for the prediction of type III effectors in bacterial genomes. Following a complete genome sequencing and assembly of an Israeli isolate of Xanthomonas hortorum pv. pelargonii - strain 305, we used Effectidor to predict effector encoding genes both in this newly sequenced genome, and in X. fragariae strain Fap21, and validated its predictions experimentally. Four and two genes in X. hortorum and X. fragariae, respectively, contained an active translocation signal that allowed the translocation of the reporter AvrBs2 that induced the hypersensitive response in pepper leaves, and are thus considered validated novel effectors. These newly validated effectors are XopBB, XopBC, XopBD, XopBE, XopBF, and XopBG.
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Affiliation(s)
- Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Daniella Ben-Meir
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Doron Teper
- Department of Plant Pathology and Weed Research, Institute of Plant Protection Agricultural Research Organization (ARO), Volcani Institute, Rishon LeZion, Israel
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Ashbolt NJ. Conceptual model to inform Legionella-amoebae control, including the roles of extracellular vesicles in engineered water system infections. Front Cell Infect Microbiol 2023; 13:1200478. [PMID: 37274310 PMCID: PMC10232903 DOI: 10.3389/fcimb.2023.1200478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023] Open
Abstract
Extracellular vesicles (EVs or exosomes) are well described for bacterial pathogens associated with our gastrointestinal system, and more recently as a novel mechanism for environmental persistence, dissemination and infection for human enteric viruses. However, the roles played by EVs in the ancient arms race that continues between amoebae and one of their prey, Legionella pneumophila, is poorly understood. At best we know of intracellular vesicles of amoebae containing a mix of bacterial prey species, which also provides an enhanced niche for bacteriophage infection/spread. Free-living amoeba-associated pathogens have recently been recognized to have enhanced resistance to disinfection and environmental stressors, adding to previously understood (but for relatively few species of) bacteria sequestered within amoebal cysts. However, the focus of the current work is to review the likely impacts of large numbers of respiratory-sized EVs containing numerous L. pneumophila cells studied in pure and biofilm systems with mixed prey species. These encapsulated pathogens are orders of magnitude more resistant to disinfection than free cells, and our engineered systems with residual disinfectants could promote evolution of resistance (including AMR), enhanced virulence and EV release. All these are key features for evolution within a dead-end human pathogen post lung infection. Traditional single-hit pathogen infection models used to estimate the probability of infection/disease and critical environmental concentrations via quantitative microbial risk assessments may also need to change. In short, recognizing that EV-packaged cells are highly virulent units for transmission of legionellae, which may also modulate/avoid human host immune responses. Key data gaps are raised and a previous conceptual model expanded upon to clarify where biofilm EVs could play a role promoting risk as well as inform a more wholistic management program to proactively control legionellosis.
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Shames SR. Eat or Be Eaten: Strategies Used by Legionella to Acquire Host-Derived Nutrients and Evade Lysosomal Degradation. Infect Immun 2023; 91:e0044122. [PMID: 36912646 PMCID: PMC10112212 DOI: 10.1128/iai.00441-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023] Open
Abstract
To replicate within host cells, bacterial pathogens must acquire host-derived nutrients while avoiding degradative antimicrobial pathways. Fundamental insights into bacterial pathogenicity have been revealed by bacteria of the genus Legionella, which naturally parasitize free-living protozoa by establishing a membrane-bound replicative niche termed the Legionella-containing vacuole (LCV). Biogenesis of the LCV and intracellular replication rely on rapid evasion of the endocytic pathway and acquisition of host-derived nutrients, much of which is mediated by bacterial effector proteins translocated into host cells by a Dot/Icm type IV secretion system. Billions of years of co-evolution with eukaryotic hosts and broad host tropism have resulted in expansion of the Legionella genome to accommodate a massive repertoire of effector proteins that promote LCV biogenesis, safeguard the LCV from endolysosomal maturation, and mediate the acquisition of host nutrients. This minireview is focused on the mechanisms by which an ancient intracellular pathogen leverages effector proteins and hijacks host cell biology to obtain essential host-derived nutrients and prevent lysosomal degradation.
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Affiliation(s)
- Stephanie R. Shames
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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Schator D, Mondino S, Berthelet J, Di Silvestre C, Ben Assaya M, Rusniok C, Rodrigues-Lima F, Wehenkel A, Buchrieser C, Rolando M. Legionella para-effectors target chromatin and promote bacterial replication. Nat Commun 2023; 14:2154. [PMID: 37059817 PMCID: PMC10104843 DOI: 10.1038/s41467-023-37885-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Accepted: 04/04/2023] [Indexed: 04/16/2023] Open
Abstract
Legionella pneumophila replicates intracellularly by secreting effectors via a type IV secretion system. One of these effectors is a eukaryotic methyltransferase (RomA) that methylates K14 of histone H3 (H3K14me3) to counteract host immune responses. However, it is not known how L. pneumophila infection catalyses H3K14 methylation as this residue is usually acetylated. Here we show that L. pneumophila secretes a eukaryotic-like histone deacetylase (LphD) that specifically targets H3K14ac and works in synergy with RomA. Both effectors target host chromatin and bind the HBO1 histone acetyltransferase complex that acetylates H3K14. Full activity of RomA is dependent on the presence of LphD as H3K14 methylation levels are significantly decreased in a ∆lphD mutant. The dependency of these two chromatin-modifying effectors on each other is further substantiated by mutational and virulence assays revealing that the presence of only one of these two effectors impairs intracellular replication, while a double knockout (∆lphD∆romA) can restore intracellular replication. Uniquely, we present evidence for "para-effectors", an effector pair, that actively and coordinately modify host histones to hijack the host response. The identification of epigenetic marks modulated by pathogens has the potential to lead to the development of innovative therapeutic strategies to counteract bacterial infection and strengthening host defences.
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Affiliation(s)
- Daniel Schator
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biologie des Bactéries Intracellulaires, 75015, Paris, France
- Sorbonne Université, Collège doctoral, 75005, Paris, France
- Herbert Wertheim School of Optometry & Vision Science, University of California, Berkeley, CA, USA
| | - Sonia Mondino
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biologie des Bactéries Intracellulaires, 75015, Paris, France
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Jérémy Berthelet
- Université Paris Cité, CNRS, Unité de Biologie Fonctionnelle et Adaptative, 75013, Paris, France
- Université Paris Cité, CNRS, UMR7126 Epigenetics and Cell Fate, 75013, Paris, France
| | - Cristina Di Silvestre
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biologie des Bactéries Intracellulaires, 75015, Paris, France
| | - Mathilde Ben Assaya
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unité de Microbiologie Structurale, 75015, Paris, France
| | - Christophe Rusniok
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biologie des Bactéries Intracellulaires, 75015, Paris, France
| | - Fernando Rodrigues-Lima
- Université Paris Cité, CNRS, Unité de Biologie Fonctionnelle et Adaptative, 75013, Paris, France
| | - Annemarie Wehenkel
- Institut Pasteur, Université Paris Cité, CNRS UMR 3528, Unité de Microbiologie Structurale, 75015, Paris, France
| | - Carmen Buchrieser
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biologie des Bactéries Intracellulaires, 75015, Paris, France.
| | - Monica Rolando
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Biologie des Bactéries Intracellulaires, 75015, Paris, France.
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Personnic N, Doublet P, Jarraud S. Intracellular persister: A stealth agent recalcitrant to antibiotics. Front Cell Infect Microbiol 2023; 13:1141868. [PMID: 37065203 PMCID: PMC10102521 DOI: 10.3389/fcimb.2023.1141868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/06/2023] [Indexed: 04/03/2023] Open
Abstract
The bulk of bacteria transiently evading appropriate antibiotic regimes and recovered from non-resolutive infections are commonly refer to as persisters. In this mini-review, we discuss how antibiotic persisters stem from the interplay between the pathogen and the cellular defenses mechanisms and its underlying heterogeneity.
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Affiliation(s)
- Nicolas Personnic
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Persistence and Single-Cell Dynamics of Respiratory Pathogens, Lyon, France
- *Correspondence: Nicolas Personnic,
| | - Patricia Doublet
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Legionella Pathogenesis, Lyon, France
| | - Sophie Jarraud
- CIRI, Centre International de Recherche en Infectiologie, CNRS UMR 5308, INSERM U1111, Ecole Normale Supérieure de Lyon, Université Claude Bernard Lyon 1, Lyon, France
- Group Legionella Pathogenesis, Lyon, France
- National Reference Centre for Legionella, Institute of Infectious Agents, Hospices Civils de Lyon, Lyon, France
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Shi Y, Liu H, Ma K, Luo ZQ, Qiu J. Legionella longbeachae Regulates the Association of Polyubiquitinated Proteins on Bacterial Phagosome with Multiple Deubiquitinases. Microbiol Spectr 2023; 11:e0417922. [PMID: 36790208 PMCID: PMC10100730 DOI: 10.1128/spectrum.04179-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 01/16/2023] [Indexed: 02/16/2023] Open
Abstract
Legionella spp. are the causative agents of a severe pneumonia known as Legionnaires' disease. Upon being engulfed by host cells, these environmental bacteria replicate intracellularly in a plasma membrane-derived niche termed Legionella-containing vacuole (LCV) in a way that requires the defective in organelle trafficking/intracellular multiplication (Dot/Icm) protein transporter. Our understanding of interactions between Legionella and its hosts was mostly based on studies of Legionella pneumophila. In this study, we found that the LCVs created by virulent Legionella longbeachae are similarly decorated by polyubiquitinated proteins to those formed by L. pneumophila and that the ubiquitin-proteasome system (UPS) is required for optimal intracellular growth of L. longbeachae. Furthermore, we utilized bioinformatics methods and the ubiquitin-vinylmethyl ester probe to obtain potential deubiquitinases (DUBs) encoded by L. longbeachae. These efforts led to the identification of 9 L. longbeachae DUBs that displayed distinct specificity toward ubiquitin chain types. Among these, LLO_1014 and LLO_2238 are associated with the LCVs and impact the accumulation of polyubiquitinated species on the bacterial phagosome. Moreover, LLO_1014 and LLO_2238 could fully restore the phenotypes associated with Δceg23 (lotB) and Δlem27 (lotC) mutants of L. pneumophila, indicating that these DUBs have similar functions. Together, these results reveal that L. longbeachae uses multiple DUBs to construct an intracellular niche for its replication. IMPORTANCE Legionella spp. are opportunistic intracellular bacterial pathogens that cause Legionnaires' disease. Legionella utilizes the Dot/Icm type IV secretion system to deliver effector protein into host cells to modulate various cellular functions. At least 26 L. pneumophila effectors are known to hijack the host ubiquitin system via diverse mechanisms. L. longbeachae is the second leading cause of Legionnaires' disease worldwide. However, our knowledge about the interactions between L. longbeachae and its hosts is very limited. Here, we found that, similar to L. pneumophila infection, the host ubiquitin proteasome system is also important for the intracellular replication of L. longbeachae. In addition, the bacterial phagosomes harboring L. longbeachae are enriched with polyubiquitinated proteins in a Dot/Icm system-dependent manner. We further identified 9 L. longbeachae proteins that function as DUBs with distinct ubiquitin chain specificity. Of note, several of the phagosome-associated L. longbeachae DUBs regulate the recruitment of polyubiquitinated proteins to the LCV.
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Affiliation(s)
- Yunjia Shi
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Center for Pathogen Biology and Infectious Diseases, The First Hospital of Jilin University, Changchun, China
| | - Hongtao Liu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Center for Pathogen Biology and Infectious Diseases, The First Hospital of Jilin University, Changchun, China
| | - Kelong Ma
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Center for Pathogen Biology and Infectious Diseases, The First Hospital of Jilin University, Changchun, China
| | - Zhao-Qing Luo
- Purdue Institute for Inflammation, Immunology and Infectious Disease and Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Jiazhang Qiu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Center for Pathogen Biology and Infectious Diseases, The First Hospital of Jilin University, Changchun, China
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St. Louis BM, Quagliato SM, Lee PC. Bacterial effector kinases and strategies to identify their target host substrates. Front Microbiol 2023; 14:1113021. [PMID: 36846793 PMCID: PMC9950578 DOI: 10.3389/fmicb.2023.1113021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/25/2023] [Indexed: 02/12/2023] Open
Abstract
Post-translational modifications (PTMs) are critical in regulating protein function by altering chemical characteristics of proteins. Phosphorylation is an integral PTM, catalyzed by kinases and reversibly removed by phosphatases, that modulates many cellular processes in response to stimuli in all living organisms. Consequently, bacterial pathogens have evolved to secrete effectors capable of manipulating host phosphorylation pathways as a common infection strategy. Given the importance of protein phosphorylation in infection, recent advances in sequence and structural homology search have significantly expanded the discovery of a multitude of bacterial effectors with kinase activity in pathogenic bacteria. Although challenges exist due to complexity of phosphorylation networks in host cells and transient interactions between kinases and substrates, approaches are continuously being developed and applied to identify bacterial effector kinases and their host substrates. In this review, we illustrate the importance of exploiting phosphorylation in host cells by bacterial pathogens via the action of effector kinases and how these effector kinases contribute to virulence through the manipulation of diverse host signaling pathways. We also highlight recent developments in the identification of bacterial effector kinases and a variety of techniques to characterize kinase-substrate interactions in host cells. Identification of host substrates provides new insights for regulation of host signaling during microbial infection and may serve as foundation for developing interventions to treat infection by blocking the activity of secreted effector kinases.
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Affiliation(s)
- Brendyn M. St. Louis
- Department of Biological Sciences, College of Liberal Arts and Sciences, Wayne State University, Detroit, MI, United States
| | - Sydney M. Quagliato
- Department of Biological Sciences, College of Liberal Arts and Sciences, Wayne State University, Detroit, MI, United States
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29
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Shi Y, Liu H, Ma K, Luo ZQ, Qiu J. Legionella longbeachae effector protein RavZ inhibits autophagy and regulates phagosome ubiquitination during infection. PLoS One 2023; 18:e0281587. [PMID: 36758031 PMCID: PMC9910735 DOI: 10.1371/journal.pone.0281587] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/26/2023] [Indexed: 02/10/2023] Open
Abstract
Legionella organisms are ubiquitous environmental bacteria that are responsible for human Legionnaires' disease, a fatal form of severe pneumonia. These bacteria replicate intracellularly in a wide spectrum of host cells within a distinct compartment termed the Legionella-containing vacuole (LCV). Effector proteins translocated by the Dot/Icm apparatus extensively modulate host cellular functions to aid in the biogenesis of the LCV and intracellular proliferation. RavZ is an L. pneumophila effector that functions as a cysteine protease to hydrolyze lipidated LC3, thereby compromising the host autophagic response to bacterial infection. In this study, we characterized the RavZ (RavZLP) ortholog in L. longbeachae (RavZLLO), the second leading cause of Legionella infections in the world. RavZLLO and RavZLP share approximately 60% sequence identity and a conserved His-Asp-Cys catalytic triad. RavZLLO is recognized by the Dot/Icm systems of both L. pneumophila and L. longbeachae. Upon translocation into the host, it suppresses autophagy signaling in cells challenged with both species, indicating the functional redundancy of RavZLLO and RavZLP. Additionally, ectopic expression of RavZLLO but not RavZLP in mammalian cells reduces the levels of cellular polyubiquitinated and polyneddylated proteins. Consistent with this process, RavZLLO regulates the accumulation of polyubiquitinated species on the LCV during L. longbeachae infection.
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Affiliation(s)
- Yunjia Shi
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Hongtao Liu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Kelong Ma
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
| | - Zhao-Qing Luo
- Purdue Institute for Inflammation, Immunology and Infectious Disease and Department of Biological Sciences, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail: (JQ); (ZQL)
| | - Jiazhang Qiu
- State Key Laboratory for Zoonotic Diseases, Key Laboratory for Zoonosis Research of the Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China
- * E-mail: (JQ); (ZQL)
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30
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Svetlicic E, Jaén-Luchoro D, Klobucar RS, Jers C, Kazazic S, Franjevic D, Klobucar G, Shelton BG, Mijakovic I. Genomic characterization and assessment of pathogenic potential of Legionella spp. isolates from environmental monitoring. Front Microbiol 2023; 13:1091964. [PMID: 36713227 PMCID: PMC9879626 DOI: 10.3389/fmicb.2022.1091964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Several species in the genus Legionella are known to cause an acute pneumonia when the aerosols containing the bacteria from man-made water systems are inhaled. The disease is usually caused by Legionella pneumophila, but other species have been implicated in the infection. The disease is frequently manifested as an outbreak, which means several people are affected when exposed to the common source of Legionella contamination. Therefor environmental surveillance which includes isolation and identification of Legionella is performed routinely. However, usually no molecular or genome-based methods are employed in further characterization of the isolates during routine environmental monitoring. During several years of such monitoring, isolates from different geographical locations were collected and 39 of them were sequenced by hybrid de novo approach utilizing short and long sequencing reads. In addition, the isolates were typed by standard culture and MALDI-TOF method. The sequencing reads were assembled and annotated to produce high-quality genomes. By employing discriminatory genome typing, four potential new species in the Legionella genus were identified, which are yet to be biochemically and morphologically characterized. Moreover, functional annotations concerning virulence and antimicrobial resistance were performed on the sequenced genomes. The study contributes to the knowledge on little-known non-pneumophila species present in man-made water systems and establishes support for future genetic relatedness studies as well as understanding of their pathogenic potential.
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Affiliation(s)
- Ema Svetlicic
- Novo Nordisk Foundation Center for Biosustainability, Kongens Lyngby, Denmark
| | - Daniel Jaén-Luchoro
- Department of Infectious Diseases (Sahlgrenska Academy) at the University of Gothenburg, Gothenburg, Sweden
| | | | - Carsten Jers
- Novo Nordisk Foundation Center for Biosustainability, Kongens Lyngby, Denmark
| | - Snjezana Kazazic
- Laboratory for Mass Spectrometry and Functional Proteomics, Ruder Boskovic Institute, Zagreb, Croatia
| | - Damjan Franjevic
- Division of Zoology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Goran Klobucar
- Division of Zoology, Department of Biology, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | | | - Ivan Mijakovic
- Novo Nordisk Foundation Center for Biosustainability, Kongens Lyngby, Denmark,Systems and Synthetic Biology Division, Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden,*Correspondence: Ivan Mijakovic,
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Guzmán-Herrador DL, Fernández-Gómez A, Llosa M. Recruitment of heterologous substrates by bacterial secretion systems for transkingdom translocation. Front Cell Infect Microbiol 2023; 13:1146000. [PMID: 36949816 PMCID: PMC10025392 DOI: 10.3389/fcimb.2023.1146000] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023] Open
Abstract
Bacterial secretion systems mediate the selective exchange of macromolecules between bacteria and their environment, playing a pivotal role in processes such as horizontal gene transfer or virulence. Among the different families of secretion systems, Type III, IV and VI (T3SS, T4SS and T6SS) share the ability to inject their substrates into human cells, opening up the possibility of using them as customized injectors. For this to happen, it is necessary to understand how substrates are recruited and to be able to engineer secretion signals, so that the transmembrane machineries can recognize and translocate the desired substrates in place of their own. Other factors, such as recruiting proteins, chaperones, and the degree of unfolding required to cross through the secretion channel, may also affect transport. Advances in the knowledge of the secretion mechanism have allowed heterologous substrate engineering to accomplish translocation by T3SS, and to a lesser extent, T4SS and T6SS into human cells. In the case of T4SS, transport of nucleoprotein complexes adds a bonus to its biotechnological potential. Here, we review the current knowledge on substrate recognition by these secretion systems, the many examples of heterologous substrate translocation by engineering of secretion signals, and the current and future biotechnological and biomedical applications derived from this approach.
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Yang JL, Li D, Zhan XY. Concept about the Virulence Factor of Legionella. Microorganisms 2022; 11:microorganisms11010074. [PMID: 36677366 PMCID: PMC9867486 DOI: 10.3390/microorganisms11010074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/23/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022] Open
Abstract
Pathogenic species of Legionella can infect human alveolar macrophages through Legionella-containing aerosols to cause a disease called Legionellosis, which has two forms: a flu-like Pontiac fever and severe pneumonia named Legionnaires' disease (LD). Legionella is an opportunistic pathogen that frequently presents in aquatic environments as a biofilm or protozoa parasite. Long-term interaction and extensive co-evolution with various genera of amoebae render Legionellae pathogenic to infect humans and also generate virulence differentiation and heterogeneity. Conventionally, the proteins involved in initiating replication processes and human macrophage infections have been regarded as virulence factors and linked to pathogenicity. However, because some of the virulence factors are associated with the infection of protozoa and macrophages, it would be more accurate to classify them as survival factors rather than virulence factors. Given that the molecular basis of virulence variations among non-pathogenic, pathogenic, and highly pathogenic Legionella has not yet been elaborated from the perspective of virulence factors, a comprehensive explanation of how Legionella infects its natural hosts, protozoans, and accidental hosts, humans is essential to show a novel concept regarding the virulence factor of Legionella. In this review, we overviewed the pathogenic development of Legionella from protozoa, the function of conventional virulence factors in the infections of protozoa and macrophages, the host's innate immune system, and factors involved in regulating the host immune response, before discussing a probably new definition for the virulence factors of Legionella.
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Qu M, Zhu H, Zhang X. Extracellular vesicle-mediated regulation of macrophage polarization in bacterial infections. Front Microbiol 2022; 13:1039040. [PMID: 36619996 PMCID: PMC9815515 DOI: 10.3389/fmicb.2022.1039040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 11/25/2022] [Indexed: 12/24/2022] Open
Abstract
Extracellular vesicles (EVs) are nanoscale membrane-enveloped vesicles secreted by prokaryotic and eukaryotic cells, which are commonly defined as membrane vesicles (MVs) and exosomes, respectively. They play critical roles in the bacteria-bacteria and bacteria-host interactions. In infectious diseases caused by bacteria, as the first line of defense against pathogens, the macrophage polarization mode commonly determines the success or failure of the host's response to pathogen aggression. M1-type macrophages secrete pro-inflammatory factors that support microbicidal activity, while alternative M2-type macrophages secrete anti-inflammatory factors that perform an antimicrobial immune response but partially allow pathogens to replicate and survive intracellularly. Membrane vesicles (MVs) released from bacteria as a distinctive secretion system can carry various components, including bacterial effectors, nucleic acids, or lipids to modulate macrophage polarization in host-pathogen interaction. Similar to MVs, bacteria-infected macrophages can secrete exosomes containing a variety of components to manipulate the phenotypic polarization of "bystander" macrophages nearby or long distance to differentiate into type M1 or M2 to regulate the course of inflammation. Exosomes can also repair tissue damage associated with the infection by upregulating the levels of anti-inflammatory factors, downregulating the pro-inflammatory factors, and regulating cellular biological behaviors. The study of the mechanisms by which EVs modulate macrophage polarization has opened new frontiers in delineating the molecular machinery involved in bacterial pathogenesis and challenges in providing new strategies for diagnosis and therapy.
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Affiliation(s)
- Mingjuan Qu
- School of Life Sciences, Ludong University, Yantai, China,Yantai Key Laboratory of Animal Pathogenetic Microbiology and Immunology, Yantai, China
| | - Hongwei Zhu
- School of Life Sciences, Ludong University, Yantai, China,Yantai Key Laboratory of Animal Pathogenetic Microbiology and Immunology, Yantai, China,Shandong Provincial Key Laboratory of Quality Safety Monitoring and Risk Assessment for Animal Products, Jinan, China
| | - Xingxiao Zhang
- School of Life Sciences, Ludong University, Yantai, China,Yantai Key Laboratory of Animal Pathogenetic Microbiology and Immunology, Yantai, China,Shandong Breeding Environmental Control Engineering Laboratory, Yantai, China,*Correspondence: Xingxiao Zhang, ✉
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Mobile Element Integration Reveals a Chromosome Dimer Resolution System in Legionellales. mBio 2022; 13:e0217122. [PMID: 36314797 PMCID: PMC9765430 DOI: 10.1128/mbio.02171-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
In bacteria, the mechanisms used to repair DNA lesions during genome replication include homologous recombination between sister chromosomes. This can lead to the formation of chromosome dimers if an odd number of crossover events occurs. The dimers must be resolved before cell separation to ensure genomic stability and cell viability. Dimer resolution is achieved by the broadly conserved dif/Xer system, which catalyzes one additional crossover event immediately prior to cell separation. While dif/Xer systems have been characterized or predicted in the vast majority of proteobacteria, no homologs to dif or xer have been identified in the order Legionellales. Here, we report the discovery of a distinct single-recombinase dif/Xer system in the intracellular pathogen Legionella pneumophila. The dif site was uncovered by our analysis of Legionella mobile element-1 (LME-1), which harbors a dif site mimic and integrates into the L. pneumophila genome via site-specific recombination. We demonstrate that lpg1867 (here named xerL) encodes a tyrosine recombinase that is necessary and sufficient for catalyzing recombination at the dif site and that deletion of dif or xerL causes filamentation along with extracellular and intracellular growth defects. We show that the dif/XerL system is present throughout Legionellales and that Coxiella burnetii XerL and its cognate dif site can functionally substitute for the native system in L. pneumophila. Finally, we describe an unexpected link between C. burnetii dif/Xer and the maintenance of its virulence plasmids. IMPORTANCE The maintenance of circular chromosomes depends on the ability to resolve aberrant chromosome dimers after they form. In most proteobacteria, broadly conserved Xer recombinases catalyze single crossovers at short, species-specific dif sites located near the replication terminus. Chromosomal dimerization leads to the formation of two copies of dif within the same molecule, leading to rapid site-specific recombination and conversion back into chromosome monomers. The apparent absence of chromosome dimer resolution mechanisms in Legionellales has been a mystery to date. By studying a phage-like mobile genetic element, LME-1, we have identified a previously unknown single-recombinase dif/Xer system that is not only widespread across Legionellales but whose activity is linked to virulence in two important human pathogens.
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Chen TT, Lin Y, Zhang S, Liu S, Song L, Zhong W, Luo ZQ, Han A. Atypical Legionella GTPase effector hijacks host vesicular transport factor p115 to regulate host lipid droplet. SCIENCE ADVANCES 2022; 8:eadd7945. [PMID: 36525490 PMCID: PMC9757750 DOI: 10.1126/sciadv.add7945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
The intracellular bacterial pathogen Legionella pneumophila uses hundreds of effector proteins to manipulate multiple processes of the host cells to establish a replicative niche known as Legionella-containing vacuole (LCV). Biogenesis of the LCV has been known to depend on host small guanosine triphosphatases (GTPases), but whether bacterial effector GTPases are also involved remains unknown. Here, we show that an ankyrin repeat containing effector LegA15 localizes directly in host lipid droplets (LDs), leading to Golgi apparatus fragmentation of the host cells by hijacking the host vesicular transport factor p115. LegA15 is a GTPase with a unique catalytic mechanism, unlike any eukaryotic small GTPases. Moreover, the effector LegA15 co-opts p115 to modulate homeostasis of the host LDs in its GTPase-dependent manner. Together, our data reveal that an atypical GTPase effector regulates the host LDs through impeding the vesicle secretion system of the host cells for intracellular life cycle of Legionella.
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Affiliation(s)
- Tao-Tao Chen
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
- The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Yanling Lin
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Shijun Zhang
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Shuxin Liu
- Department of Respiratory Medicine and Center of Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, State Key Laboratory of Zoonotic Diseases, The First Hospital, Jilin University, Changchun, China
| | - Lei Song
- Department of Respiratory Medicine and Center of Pathogen Biology and Infectious Diseases, Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, State Key Laboratory of Zoonotic Diseases, The First Hospital, Jilin University, Changchun, China
| | - Wenhong Zhong
- The Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of the Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou, China
| | - Zhao-Qing Luo
- Purdue Institute of Inflammation, Immunology and Infectious Disease, Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences and Faculty of Medicine, Xiamen University, Xiamen, Fujian 361102, China
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Krysińska M, Baranowski B, Deszcz B, Pawłowski K, Gradowski M. Pan-kinome of Legionella expanded by a bioinformatics survey. Sci Rep 2022; 12:21782. [PMID: 36526881 PMCID: PMC9758233 DOI: 10.1038/s41598-022-26109-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
The pathogenic Legionella bacteria are notorious for delivering numerous effector proteins into the host cell with the aim of disturbing and hijacking cellular processes for their benefit. Despite intensive studies, many effectors remain uncharacterized. Motivated by the richness of Legionella effector repertoires and their oftentimes atypical biochemistry, also by several known atypical Legionella effector kinases and pseudokinases discovered recently, we undertook an in silico survey and exploration of the pan-kinome of the Legionella genus, i.e., the union of the kinomes of individual species. In this study, we discovered 13 novel (pseudo)kinase families (all are potential effectors) with the use of non-standard bioinformatic approaches. Together with 16 known families, we present a catalog of effector and non-effector protein kinase-like families within Legionella, available at http://bioinfo.sggw.edu.pl/kintaro/ . We analyze and discuss the likely functional roles of the novel predicted kinases. Notably, some of the kinase families are also present in other bacterial taxa, including other pathogens, often phylogenetically very distant from Legionella. This work highlights Nature's ingeniousness in the pathogen-host arms race and offers a useful resource for the study of infection mechanisms.
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Affiliation(s)
- Marianna Krysińska
- grid.13276.310000 0001 1955 7966Department of Biochemistry and Microbiology, Warsaw University of Life Sciences — SGGW, Warsaw, Poland
| | - Bartosz Baranowski
- grid.413454.30000 0001 1958 0162Laboratory of Plant Pathogenesis, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Bartłomiej Deszcz
- grid.13276.310000 0001 1955 7966Department of Biochemistry and Microbiology, Warsaw University of Life Sciences — SGGW, Warsaw, Poland
| | - Krzysztof Pawłowski
- grid.13276.310000 0001 1955 7966Department of Biochemistry and Microbiology, Warsaw University of Life Sciences — SGGW, Warsaw, Poland ,grid.267313.20000 0000 9482 7121Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX USA ,grid.4514.40000 0001 0930 2361Department of Translational Medicine, Lund University, Lund, Sweden ,grid.413575.10000 0001 2167 1581Howard Hughes Medical Institute, Dallas, TX, USA
| | - Marcin Gradowski
- grid.13276.310000 0001 1955 7966Department of Biochemistry and Microbiology, Warsaw University of Life Sciences — SGGW, Warsaw, Poland
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37
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Analysis of the Type 4 Effectome across the Genus Rickettsia. Int J Mol Sci 2022; 23:ijms232415513. [PMID: 36555155 PMCID: PMC9779031 DOI: 10.3390/ijms232415513] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/13/2022] Open
Abstract
Rickettsia are obligate intracellular bacteria primarily carried by arthropod hosts. The genus Rickettsia contains several vertebrate pathogens vectored by hematophagous arthropods. Despite the potential for disease, our understanding of Rickettsias are limited by the difficulties associated with growing and manipulating obligate intracellular bacteria. To aid with this, our lab conducted an analysis of eight genomes and three plasmids from across the genus Rickettsia. Using OPT4e, a learning algorithm-based program designed to identify effector proteins secreted by the type 4 secretion system, we generated a putative effectome for the genus. We then consolidated effectors into homolog sets to identify effectors unique to Rickettsia with different life strategies or evolutionary histories. We also compared predicted effectors to non-effectors for differences in G+C content and gene splitting. Based on this analysis, we predicted 1571 effectors across the genus, resulting in 604 homolog sets. Each species had unique homolog sets, while 42 were present in all eight species analyzed. Effectors were flagged in association with pathogenic, tick and flea-borne Rickettsia. Predicted effectors also varied in G+C content and frequency of gene splitting as compared to non-effectors. Species effector repertoires show signs of expansion, degradation, and horizontal acquisition associated with lifestyle and lineage.
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38
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Wagner N, Alburquerque M, Ecker N, Dotan E, Zerah B, Pena MM, Potnis N, Pupko T. Natural language processing approach to model the secretion signal of type III effectors. FRONTIERS IN PLANT SCIENCE 2022; 13:1024405. [PMID: 36388586 PMCID: PMC9659976 DOI: 10.3389/fpls.2022.1024405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Accepted: 10/11/2022] [Indexed: 06/16/2023]
Abstract
Type III effectors are proteins injected by Gram-negative bacteria into eukaryotic hosts. In many plant and animal pathogens, these effectors manipulate host cellular processes to the benefit of the bacteria. Type III effectors are secreted by a type III secretion system that must "classify" each bacterial protein into one of two categories, either the protein should be translocated or not. It was previously shown that type III effectors have a secretion signal within their N-terminus, however, despite numerous efforts, the exact biochemical identity of this secretion signal is generally unknown. Computational characterization of the secretion signal is important for the identification of novel effectors and for better understanding the molecular translocation mechanism. In this work we developed novel machine-learning algorithms for characterizing the secretion signal in both plant and animal pathogens. Specifically, we represented each protein as a vector in high-dimensional space using Facebook's protein language model. Classification algorithms were next used to separate effectors from non-effector proteins. We subsequently curated a benchmark dataset of hundreds of effectors and thousands of non-effector proteins. We showed that on this curated dataset, our novel approach yielded substantially better classification accuracy compared to previously developed methodologies. We have also tested the hypothesis that plant and animal pathogen effectors are characterized by different secretion signals. Finally, we integrated the novel approach in Effectidor, a web-server for predicting type III effector proteins, leading to a more accurate classification of effectors from non-effectors.
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Affiliation(s)
- Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Michael Alburquerque
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Noa Ecker
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Edo Dotan
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Ben Zerah
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Michelle Mendonca Pena
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, AL, United States
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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39
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Chen TT, Lin Y, Zhang S, Han A. Structural basis for the acetylation mechanism of the Legionella effector VipF. Acta Crystallogr D Struct Biol 2022; 78:1110-1119. [DOI: 10.1107/s2059798322007318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 07/14/2022] [Indexed: 11/11/2022] Open
Abstract
The pathogen Legionella pneumophila, which is the causative agent of Legionnaires' disease, secrets hundreds of effectors into host cells via its Dot/Icm secretion system to subvert host-cell pathways during pathogenesis. VipF, a conserved core effector among Legionella species, is a putative acetyltransferase, but its structure and catalytic mechanism remain unknown. Here, three crystal structures of VipF in complex with its cofactor acetyl-CoA and/or a substrate are reported. The two GNAT-like domains of VipF are connected as two wings by two β-strands to form a U-shape. Both domains bind acetyl-CoA or CoA, but only in the C-terminal domain does the molecule extend to the bottom of the U-shaped groove as required for an active transferase reaction; the molecule in the N-terminal domain folds back on itself. Interestingly, when chloramphenicol, a putative substrate, binds in the pocket of the central U-shaped groove adjacent to the N-terminal domain, VipF remains in an open conformation. Moreover, mutations in the central U-shaped groove, including Glu129 and Asp251, largely impaired the acetyltransferase activity of VipF, suggesting a unique enzymatic mechanism for the Legionella effector VipF.
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40
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Lockwood DC, Amin H, Costa TRD, Schroeder GN. The Legionella pneumophila Dot/Icm type IV secretion system and its effectors. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35639581 DOI: 10.1099/mic.0.001187] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
To prevail in the interaction with eukaryotic hosts, many bacterial pathogens use protein secretion systems to release virulence factors at the host–pathogen interface and/or deliver them directly into host cells. An outstanding example of the complexity and sophistication of secretion systems and the diversity of their protein substrates, effectors, is the Defective in organelle trafficking/Intracellular multiplication (Dot/Icm) Type IVB secretion system (T4BSS) of
Legionella pneumophila
and related species.
Legionella
species are facultative intracellular pathogens of environmental protozoa and opportunistic human respiratory pathogens. The Dot/Icm T4BSS translocates an exceptionally large number of effectors, more than 300 per
L. pneumophila
strain, and is essential for evasion of phagolysosomal degradation and exploitation of protozoa and human macrophages as replicative niches. Recent technological advancements in the imaging of large protein complexes have provided new insight into the architecture of the T4BSS and allowed us to propose models for the transport mechanism. At the same time, significant progress has been made in assigning functions to about a third of
L. pneumophila
effectors, discovering unprecedented new enzymatic activities and concepts of host subversion. In this review, we describe the current knowledge of the workings of the Dot/Icm T4BSS machinery and provide an overview of the activities and functions of the to-date characterized effectors in the interaction of
L. pneumophila
with host cells.
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Affiliation(s)
- Daniel C Lockwood
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, BT9 7BL, Northern Ireland, UK
| | - Himani Amin
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Tiago R D Costa
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, SW7 2AZ, UK
| | - Gunnar N Schroeder
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, BT9 7BL, Northern Ireland, UK
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41
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Extensive epigenetic modification with large-scale chromosomal and plasmid recombination characterise the Legionella longbeachae serogroup 1 genome. Sci Rep 2022; 12:5810. [PMID: 35388097 PMCID: PMC8987031 DOI: 10.1038/s41598-022-09721-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 03/15/2022] [Indexed: 11/08/2022] Open
Abstract
Legionella longbeachae is an environmental bacterium that is the most clinically significant Legionella species in New Zealand (NZ), causing around two-thirds of all notified cases of Legionnaires’ disease. Here we report the sequencing and analysis of the geo-temporal genetic diversity of 54 L. longbeachae serogroup 1 (sg1) clinical isolates, derived from cases from around NZ over a 22-year period, including one complete genome and its associated methylome. The 54 sg1 isolates belonged to two main clades that last shared a common ancestor between 95 BCE and 1694 CE. There was diversity at the genome-structural level, with large-scale arrangements occurring in some regions of the chromosome and evidence of extensive chromosomal and plasmid recombination. This includes the presence of plasmids derived from recombination and horizontal gene transfer between various Legionella species, indicating there has been both intra- and inter-species gene flow. However, because similar plasmids were found among isolates within each clade, plasmid recombination events may pre-empt the emergence of new L. longbeachae strains. Our complete NZ reference genome consisted of a 4.1 Mb chromosome and a 108 kb plasmid. The genome was highly methylated with two known epigenetic modifications, m4C and m6A, occurring in particular sequence motifs within the genome.
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42
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Song L, Luo J, Wang H, Huang D, Tan Y, Liu Y, Wang Y, Yu K, Zhang Y, Liu X, Li D, Luo ZQ. Legionella pneumophila regulates host cell motility by targeting Phldb2 with a 14-3-3ζ-dependent protease effector. eLife 2022; 11:73220. [PMID: 35175192 PMCID: PMC8871388 DOI: 10.7554/elife.73220] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 02/16/2022] [Indexed: 11/18/2022] Open
Abstract
The cytoskeleton network of eukaryotic cells is essential for diverse cellular processes, including vesicle trafficking, cell motility, and immunity, thus is a common target for bacterial virulence factors. A number of effectors from the bacterial pathogen Legionella pneumophila have been shown to modulate the function of host actin cytoskeleton to construct the Legionella-containing vacuole (LCV) permissive for its intracellular replication. In this study, we found that the Dot/Icm effector Lem8 (Lpg1290) is a protease whose activity is catalyzed by a Cys-His-Asp motif known to be associated with diverse biochemical activities. Intriguingly, we found that Lem8 interacts with the host regulatory protein 14-3-3ζ, which activates its protease activity. Furthermore, Lem8 undergoes self-cleavage in a process that requires 14-3-3ζ. We identified the Pleckstrin homology-like domain-containing protein Phldb2 involved in cytoskeleton organization as a target of Lem8 and demonstrated that Lem8 plays a role in the inhibition of host cell migration by attacking Phldb2.
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Affiliation(s)
- Lei Song
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Jingjing Luo
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Hongou Wang
- Department of Microbiology, Peking University Health Science Center, Peking, China
| | - Dan Huang
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Yunhao Tan
- Department of Biological Sciences, Purdue University, West Lafayette, United States
| | - Yao Liu
- Department of Biological Sciences, Purdue University, West Lafayette, United States
| | - Yingwu Wang
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Kaiwen Yu
- Department of Microbiology, Peking University Health Science Center, Peking, China
| | - Yong Zhang
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Xiaoyun Liu
- Department of Microbiology, Peking University Health Science Center, Peking, China
| | - Dan Li
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Zhao-Qing Luo
- Department of Biological Science, Purdue University, West Lafayette, United States
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43
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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.
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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
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44
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Hugoson E, Guliaev A, Ammunét T, Guy L. Host-adaptation in Legionellales is 1.9 Ga, coincident with eukaryogenesis. Mol Biol Evol 2022; 39:6527638. [PMID: 35167692 PMCID: PMC8896642 DOI: 10.1093/molbev/msac037] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Bacteria adapting to living in a host cell caused the most salient events in the evolution of eukaryotes, namely the seminal fusion with an archaeon, and the emergence of both mitochondrion and chloroplast. A bacterial clade that may hold the key to understanding these events is the deep-branching gammaproteobacterial order Legionellales-containing among others Coxiella and Legionella-of which all known members grow inside eukaryotic cells. Here, by analyzing 35 novel Legionellales genomes mainly acquired through metagenomics, we show that this group is much more diverse than previously thought, and that key host-adaptation events took place very early in its evolution. Crucial virulence factors like the Type IVB secretion (Dot/Icm) system and two shared effector proteins were gained in the last Legionellales common ancestor (LLCA). Many metabolic gene families were lost in LLCA and its immediate descendants, including functions directly and indirectly related to molybdenum metabolism. On the other hand, genome sizes increased in the ancestors of the Legionella genus. We estimate that LLCA lived circa 1.89 Ga ago, probably predating the last eukaryotic common ancestor (LECA) by circa 0.4-1.0 Ga. These elements strongly indicate that host-adaptation arose only once in Legionellales, and that these bacteria were using advanced molecular machinery to exploit and manipulate host cells early in eukaryogenesis.
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Affiliation(s)
- Eric Hugoson
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratories, Uppsala University, Box 582, 75123, Uppsala, Sweden.,Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön, D-24306, Germany
| | - Andrei Guliaev
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratories, Uppsala University, Box 582, 75123, Uppsala, Sweden
| | - Tea Ammunét
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratories, Uppsala University, Box 582, 75123, Uppsala, Sweden
| | - Lionel Guy
- Department of Medical Biochemistry and Microbiology, Science for Life Laboratories, Uppsala University, Box 582, 75123, Uppsala, Sweden
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45
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Fu J, Zhou M, Gritsenko MA, Nakayasu ES, Song L, Luo ZQ. Legionella pneumophila modulates host energy metabolism by ADP-ribosylation of ADP/ATP translocases. eLife 2022; 11:73611. [PMID: 35084332 PMCID: PMC8820735 DOI: 10.7554/elife.73611] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 01/26/2022] [Indexed: 11/13/2022] Open
Abstract
The intracellular pathogen Legionella pneumophila delivers more than 330 effectors into host cells by its Dot/Icm secretion system. Those effectors direct the biogenesis of the Legionella-containing vacuole (LCV) that permits its intracellular survival and replication. It has long been documented that the LCV is associated with mitochondria and a number of Dot/Icm effectors have been shown to target to this organelle. Yet, the biochemical function and host cell target of most of these effectors remain unknown. Here, we found that the Dot/Icm substrate Ceg3 (Lpg0080) is a mono-ADP-ribosyltransferase that localizes to the mitochondria in host cells where it attacks ADP/ATP translocases by ADP-ribosylation, and blunts their ADP/ATP exchange activity. The modification occurs on the second arginine residue in the -RRRMMM- element, which is conserved among all known ADP/ATP carriers from different organisms. Our results reveal modulation of host energy metabolism as a virulence mechanism for L. pneumophila.
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Affiliation(s)
- Jiaqi Fu
- Department of Biological Science, Purdue University, West Lafayette, United States
| | - Mowei Zhou
- Environmental and Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, United States
| | - Marina A Gritsenko
- Biological Science Division, Pacific Northwest National Laboratory, Richland, United States
| | - Ernesto S Nakayasu
- Biological Science Division, Pacific Northwest National Laboratory, Richland, United States
| | - Lei Song
- Department of Respiratory Medicine, Jilin University, Changchun, China
| | - Zhao-Qing Luo
- Department of Biological Science, Purdue University, West Lafayette, United States
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46
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Talapko J, Frauenheim E, Juzbašić M, Tomas M, Matić S, Jukić M, Samardžić M, Škrlec I. Legionella pneumophila-Virulence Factors and the Possibility of Infection in Dental Practice. Microorganisms 2022; 10:microorganisms10020255. [PMID: 35208710 PMCID: PMC8879694 DOI: 10.3390/microorganisms10020255] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/08/2022] [Accepted: 01/21/2022] [Indexed: 02/07/2023] Open
Abstract
Legionella pneumophila is defined as a bacterium that can cause severe pneumonia. It is found in the natural environment and in water, and is often found in water tanks. It can be an integral part of biofilms in nature, and the protozoa in which it can live provide it with food and protect it from harmful influences; therefore, it has the ability to move into a sustainable but uncultured state (VBNC). L. pneumophila has been shown to cause infections in dental practices. The most common transmission route is aerosol generated in dental office water systems, which can negatively affect patients and healthcare professionals. The most common way of becoming infected with L. pneumophila in a dental office is through water from dental instruments, and the dental unit. In addition to these bacteria, patients and the dental team may be exposed to other harmful bacteria and viruses. Therefore, it is vital that the dental team regularly maintains and decontaminates the dental unit, and sterilizes all accessories that come with it. In addition, regular water control in dental offices is necessary.
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Affiliation(s)
- Jasminka Talapko
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Erwin Frauenheim
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Martina Juzbašić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Matej Tomas
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Suzana Matić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
- Faculty of Medicine, Josip Juraj Strossmayer University of Osijek, Josipa Huttlera 4, HR-31000 Osijek, Croatia
| | - Melita Jukić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
- General Hospital Vukovar, Županijska 35, HR-32000 Vukovar, Croatia
| | - Marija Samardžić
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
| | - Ivana Škrlec
- Faculty of Dental Medicine and Health, Josip Juraj Strossmayer University of Osijek, HR-31000 Osijek, Croatia; (J.T.); (E.F.); (M.J.); (M.T.); (S.M.); (M.J.); (M.S.)
- Correspondence:
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The Legionella genus core effectors display functional conservation among orthologs by themselves or combined with an accessory protein. CURRENT RESEARCH IN MICROBIAL SCIENCES 2022; 3:100105. [PMID: 35059677 PMCID: PMC8760000 DOI: 10.1016/j.crmicr.2022.100105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 01/03/2022] [Accepted: 01/06/2022] [Indexed: 12/03/2022] Open
Abstract
The Legionella genus contains nine core effectors. Three Legionella pneumophila core effectors are required for intracellular growth. The Legionella genus core effectors display functional conservation among orthologs. One Legionella core effector requires an accessory protein to perform its function.
The intracellular pathogen Legionella pneumophila, as well as other Legionella species, utilize the Icm/Dot type-IV secretion system to translocate an exceptionally large and diverse repertoire of effectors into their host cells. However, only nine core effectors were found to be present in all analyzed Legionella species. In this study, we investigated the core effectors, and used intracellular growth complementation to determine whether orthologs of core effectors perform the same function in different Legionella species. We found that three out of the nine L. pneumophila core effectors are required for maximal intracellular growth. Examination of orthologous core effectors from four Legionella species spread over the Legionella phylogenetic tree revealed that most of them perform the same function. Nevertheless, some of the orthologs of the core effector LegA3 did not complement the L. pneumophila legA3 deletion mutant for intracellular growth. LegA3 is encoded as part of an operon together with another gene, which we named legA3C, encoding a non-translocated protein. We found that LegA3 and LegA3C physically interact with each other, are both required for maximal intracellular growth, and the LegA3-LegA3C orthologous pairs from all the Legionella species examined fully complement the L. pneumophila legA3 deletion mutant for intracellular growth. Our results indicate that the Legionella core effectors orthologs generally perform the same function and establish that LegA3 requires LegA3C to fulfill its conserved function.
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Wee BA, Alves J, Lindsay DSJ, Klatt AB, Sargison FA, Cameron RL, Pickering A, Gorzynski J, Corander J, Marttinen P, Opitz B, Smith AJ, Fitzgerald JR. Population analysis of Legionella pneumophila reveals a basis for resistance to complement-mediated killing. Nat Commun 2021; 12:7165. [PMID: 34887398 PMCID: PMC8660822 DOI: 10.1038/s41467-021-27478-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 11/19/2021] [Indexed: 11/09/2022] Open
Abstract
Legionella pneumophila is the most common cause of the severe respiratory infection known as Legionnaires' disease. However, the microorganism is typically a symbiont of free-living amoeba, and our understanding of the bacterial factors that determine human pathogenicity is limited. Here we carried out a population genomic study of 902 L. pneumophila isolates from human clinical and environmental samples to examine their genetic diversity, global distribution and the basis for human pathogenicity. We find that the capacity for human disease is representative of the breadth of species diversity although some clones are more commonly associated with clinical infections. We identified a single gene (lag-1) to be most strongly associated with clinical isolates. lag-1, which encodes an O-acetyltransferase for lipopolysaccharide modification, has been distributed horizontally across all major phylogenetic clades of L. pneumophila by frequent recent recombination events. The gene confers resistance to complement-mediated killing in human serum by inhibiting deposition of classical pathway molecules on the bacterial surface. Furthermore, acquisition of lag-1 inhibits complement-dependent phagocytosis by human neutrophils, and promoted survival in a mouse model of pulmonary legionellosis. Thus, our results reveal L. pneumophila genetic traits linked to disease and provide a molecular basis for resistance to complement-mediated killing.
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Affiliation(s)
- Bryan A. Wee
- grid.4305.20000 0004 1936 7988The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland UK
| | - Joana Alves
- grid.4305.20000 0004 1936 7988The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland UK
| | - Diane S. J. Lindsay
- Bacterial Respiratory Infections Service (Ex Mycobacteria), Scottish Microbiology Reference Laboratory, Glasgow, Scotland UK
| | - Ann-Brit Klatt
- grid.6363.00000 0001 2218 4662Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Fiona A. Sargison
- grid.4305.20000 0004 1936 7988The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland UK
| | - Ross L. Cameron
- grid.413893.40000 0001 2232 4338NHS National Services Scotland, Health Protection Scotland, Glasgow, Scotland UK
| | - Amy Pickering
- grid.4305.20000 0004 1936 7988The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland UK
| | - Jamie Gorzynski
- grid.4305.20000 0004 1936 7988The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland UK
| | - Jukka Corander
- grid.7737.40000 0004 0410 2071Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland ,grid.5510.10000 0004 1936 8921Department of Biostatistics, University of Oslo, Oslo, Norway
| | - Pekka Marttinen
- grid.500231.50000 0004 0530 9461Helsinki Institute for Information Technology, Department of Computer Science, Aalto University, Aalto, Finland
| | - Bastian Opitz
- grid.6363.00000 0001 2218 4662Department of Internal Medicine/Infectious Diseases and Pulmonary Medicine, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Andrew J. Smith
- Bacterial Respiratory Infections Service (Ex Mycobacteria), Scottish Microbiology Reference Laboratory, Glasgow, Scotland UK ,grid.8756.c0000 0001 2193 314XCollege of Medical, Veterinary & Life Sciences, Glasgow Dental Hospital & School, University of Glasgow, Glasgow, UK
| | - J. Ross Fitzgerald
- grid.4305.20000 0004 1936 7988The Roslin Institute, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, Scotland UK
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Chung IYW, Li L, Cygler M. Legionella effector LegA15/AnkH contains an unrecognized cysteine protease-like domain and displays structural similarity to LegA3/AnkD, but differs in host cell localization. Acta Crystallogr D Struct Biol 2021; 77:1535-1542. [PMID: 34866609 DOI: 10.1107/s2059798321010469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/08/2021] [Indexed: 11/11/2022] Open
Abstract
Legionella pneumophila is a human pathogen that causes Legionnaires' disease, a severe form of pneumonia. It can be found in various aquatic environments ranging from cooling towers to ponds. In addition to causing disease in humans, it can also infect free-living amoebae commonly found in various aquatic environments. Once inside a human lung macrophage, it creates a niche called the Legionella-containing vacuole where it can evade phagolysosomal degradation and replicate. During infection, normal cellular functions are hijacked by proteins that are secreted by the pathogen, called bacterial effectors. Here, the structural characterization of the effector LegA15/AnkD is reported. The protein contains an ankyrin-repeat domain followed by a cysteine protease-like (CPL) domain with a putative catalytic triad consisting of His268-Asn290-Cys361. The CPL domain shows similarity to the CE clan in the MEROPS database, which contains ubiquitin-like hydrolases. The C-terminal segment of LegA15, including the CPL domain, shows structural similarity to another effector, LegA3/AnkH, while they share only 12% sequence identity. When expressed in mammalian cells, LegA15 is localized within the cytoplasm, in contrast to LegA3, which localizes to the nucleus.
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Affiliation(s)
- Ivy Yeuk Wah Chung
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Lei Li
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Miroslaw Cygler
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
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Iyer S, Das C. The unity of opposites: Strategic interplay between bacterial effectors to regulate cellular homeostasis. J Biol Chem 2021; 297:101340. [PMID: 34695417 PMCID: PMC8605245 DOI: 10.1016/j.jbc.2021.101340] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 10/15/2021] [Accepted: 10/20/2021] [Indexed: 11/23/2022] Open
Abstract
Legionella pneumophila is a facultative intracellular pathogen that uses the Dot/Icm Type IV secretion system (T4SS) to translocate many effectors into its host and establish a safe, replicative lifestyle. The bacteria, once phagocytosed, reside in a vacuolar structure known as the Legionella-containing vacuole (LCV) within the host cells and rapidly subvert organelle trafficking events, block inflammatory responses, hijack the host ubiquitination system, and abolish apoptotic signaling. This arsenal of translocated effectors can manipulate the host factors in a multitude of different ways. These proteins also contribute to bacterial virulence by positively or negatively regulating the activity of one another. Such effector-effector interactions, direct and indirect, provide the delicate balance required to maintain cellular homeostasis while establishing itself within the host. This review summarizes the recent progress in our knowledge of the structure-function relationship and biochemical mechanisms of select effector pairs from Legionella that work in opposition to one another, while highlighting the diversity of biochemical means adopted by this intracellular pathogen to establish a replicative niche within host cells.
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Affiliation(s)
- Shalini Iyer
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA.
| | - Chittaranjan Das
- Department of Chemistry, Purdue University, West Lafayette, Indiana, USA.
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