1
|
Cabello AL, Wells K, Peng W, Feng HQ, Wang J, Meyer DF, Noroy C, Zhao ES, Zhang H, Li X, Chang H, Gomez G, Mao Y, Patrick KL, Watson RO, Russell WK, Yu A, Zhong J, Guo F, Li M, Zhou M, Qian X, Kobayashi KS, Song J, Panthee S, Mechref Y, Ficht TA, Qin QM, de Figueiredo P. Brucella-driven host N-glycome remodeling controls infection. Cell Host Microbe 2024; 32:588-605.e9. [PMID: 38531364 DOI: 10.1016/j.chom.2024.03.003] [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: 09/14/2022] [Revised: 08/28/2023] [Accepted: 03/06/2024] [Indexed: 03/28/2024]
Abstract
Many powerful methods have been employed to elucidate the global transcriptomic, proteomic, or metabolic responses to pathogen-infected host cells. However, the host glycome responses to bacterial infection remain largely unexplored, and hence, our understanding of the molecular mechanisms by which bacterial pathogens manipulate the host glycome to favor infection remains incomplete. Here, we address this gap by performing a systematic analysis of the host glycome during infection by the bacterial pathogen Brucella spp. that cause brucellosis. We discover, surprisingly, that a Brucella effector protein (EP) Rhg1 induces global reprogramming of the host cell N-glycome by interacting with components of the oligosaccharide transferase complex that controls N-linked protein glycosylation, and Rhg1 regulates Brucella replication and tissue colonization in a mouse model of brucellosis, demonstrating that Brucella exploits the EP Rhg1 to reprogram the host N-glycome and promote bacterial intracellular parasitism, thereby providing a paradigm for bacterial control of host cell infection.
Collapse
Affiliation(s)
- Ana-Lucia Cabello
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843, USA; Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Kelsey Wells
- Christopher S. Bond Life Sciences Center, Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65211, USA
| | - Wenjing Peng
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
| | - Hui-Qiang Feng
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Junyao Wang
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
| | - Damien F Meyer
- CIRAD, UMR ASTRE, 97170 Petit-Bourg, Guadeloupe, France; ASTRE, University Montpellier, CIRAD, INRAE, Montpellier, France
| | - Christophe Noroy
- CIRAD, UMR ASTRE, 97170 Petit-Bourg, Guadeloupe, France; ASTRE, University Montpellier, CIRAD, INRAE, Montpellier, France
| | - En-Shuang Zhao
- College of Computer Science and Technology, Jilin University, Changchun 130012, China
| | - Hao Zhang
- College of Computer Science and Technology, Jilin University, Changchun 130012, China
| | - Xueqing Li
- College of Computer Science and Technology, Jilin University, Changchun 130012, China
| | - Haowu Chang
- College of Computer Science and Technology, Jilin University, Changchun 130012, China
| | - Gabriel Gomez
- Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL), Texas A&M University, College Station, TX 77843, USA
| | - Yuxin Mao
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853-2703, USA
| | - Kristin L Patrick
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Robert O Watson
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - William K Russell
- Department of Biochemistry & Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555-0635, USA
| | - Aiying Yu
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
| | - Jieqiang Zhong
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA
| | - Fengguang Guo
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Mingqian Li
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 78843, USA
| | - Mingyuan Zhou
- Department of Information, Risk, and Operations Management, Department of Statistics and Data Sciences, The University of Texas at Austin, Austin, TX 78712, USA
| | - Xiaoning Qian
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 78843, USA; TEES-AgriLife Center for Bioinformatics & Genomic Systems Engineering, Texas A&M University, College Station, TX 77843, USA
| | - Koichi S Kobayashi
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA; Department of Immunology, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan; Hokkaido University, Institute for Vaccine Research and Development (HU-IVReD), Sapporo 060-8638, Japan
| | - Jianxun Song
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Suresh Panthee
- Department of Microbial Pathogenesis and Immunology, Texas A&M Health Science Center, Bryan, TX 77807, USA
| | - Yehia Mechref
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA.
| | - Thomas A Ficht
- Department of Veterinary Pathobiology, Texas A&M University, College Station, TX 77843, USA.
| | - Qing-Ming Qin
- Christopher S. Bond Life Sciences Center, Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65211, USA.
| | - Paul de Figueiredo
- Christopher S. Bond Life Sciences Center, Department of Molecular Microbiology and Immunology, School of Medicine, The University of Missouri, Columbia, MO 65211, USA; Department of Veterinary Pathobiology, The University of Missouri, Columbia, MO 65211, USA.
| |
Collapse
|
2
|
Martin M, López-Madrigal S, Newton ILG. The Wolbachia WalE1 effector alters Drosophila endocytosis. PLoS Pathog 2024; 20:e1011245. [PMID: 38547310 PMCID: PMC11003677 DOI: 10.1371/journal.ppat.1011245] [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: 02/25/2023] [Revised: 04/09/2024] [Accepted: 03/18/2024] [Indexed: 04/09/2024] Open
Abstract
The most common intracellular bacterial infection is Wolbachia pipientis, a microbe that manipulates host reproduction and is used in control of insect vectors. Phenotypes induced by Wolbachia have been studied for decades and range from sperm-egg incompatibility to male killing. How Wolbachia alters host biology is less well understood. Previously, we characterized the first Wolbachia effector-WalE1, which encodes an alpha-synuclein domain at the N terminus. Purified WalE1 sediments with and bundles actin and when heterologously expressed in flies, increases Wolbachia titer in the developing oocyte. In this work, we first identify the native expression of WalE1 by Wolbachia infecting both fly cells and whole animals. WalE1 appears as aggregates in the host cell cytosol. We next show that WalE1 co-immunoprecipitates with the host protein Past1, although might not directly interact with it, and that WalE1 manipulates host endocytosis. Yeast expressing WalE1 show deficiency in uptake of FM4-64 dye, and flies harboring mutations in Past1 or overexpressing WalE1 are sensitive to AgNO3, a hallmark of endocytosis defects. We also show that flies expressing WalE1 suffer from endocytosis defects in larval nephrocytes. Finally, we also show that Past1 null flies harbor more Wolbachia overall and in late egg chambers. Our results identify interactions between Wolbachia and a host protein involved in endocytosis and point to yet another important host cell process impinged upon by Wolbachia's WalE1 effector.
Collapse
Affiliation(s)
- MaryAnn Martin
- Department of Biology, Indiana University, Bloomington, Indiana United States of America
| | - Sergio López-Madrigal
- Department of Biology, Indiana University, Bloomington, Indiana United States of America
| | - Irene L. G. Newton
- Department of Biology, Indiana University, Bloomington, Indiana United States of America
| |
Collapse
|
3
|
Martin M, Newton ILG. The Wolbachia WalE1 effector alters Drosophila endocytosis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.26.530160. [PMID: 36909520 PMCID: PMC10002650 DOI: 10.1101/2023.02.26.530160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
The most common intracellular bacterial infection is Wolbachia pipientis, a microbe that manipulates host reproduction and is used in control of insect vectors. Phenotypes induced by Wolbachia have been studied for decades and range from sperm-egg incompatibility to male killing. How Wolbachia alters host biology is less well understood. Previously, we characterized the first Wolbachia effector - WalE1, which encodes a synuclein domain at the N terminus. Purified WalE1 sediments with and bundles actin and when heterologously expressed in flies, increases Wolbachia titer in the developing oocyte. In this work, we first identify the native expression WalE1 by Wolbachia infecting both fly cells and whole animals. WalE1 appears as aggregates, separate from Wolbachia cells. We next show that WalE1 co-immunoprecipitates with the host protein Past1 and that WalE1 manipulates host endocytosis. Yeast expressing WalE1 show deficiency in uptake of FM4-64 dye, and flies harboring mutations in Past1 or overexpressing WalE1 are sensitive to AgNO3, a hallmark of endocytosis defects. Finally, we also show that Past1 null flies harbor more Wolbachia overall and in late egg chambers. Our results identify interactions between a Wolbachia secreted effector and a host protein and point to yet another important host cell process impinged upon by Wolbachia.
Collapse
Affiliation(s)
- MaryAnn Martin
- Department of Biology, Indiana University, Bloomington, IN USA
| | | |
Collapse
|
4
|
McDermott JE, Cort JR, Nakayasu ES, Pruneda JN, Overall C, Adkins JN. Prediction of bacterial E3 ubiquitin ligase effectors using reduced amino acid peptide fingerprinting. PeerJ 2019; 7:e7055. [PMID: 31211016 PMCID: PMC6557245 DOI: 10.7717/peerj.7055] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 05/02/2019] [Indexed: 11/20/2022] Open
Abstract
Background Although pathogenic Gram-negative bacteria lack their own ubiquitination machinery, they have evolved or acquired virulence effectors that can manipulate the host ubiquitination process through structural and/or functional mimicry of host machinery. Many such effectors have been identified in a wide variety of bacterial pathogens that share little sequence similarity amongst themselves or with eukaryotic ubiquitin E3 ligases. Methods To allow identification of novel bacterial E3 ubiquitin ligase effectors from protein sequences we have developed a machine learning approach, the SVM-based Identification and Evaluation of Virulence Effector Ubiquitin ligases (SIEVE-Ub). We extend the string kernel approach used previously to sequence classification by introducing reduced amino acid (RED) alphabet encoding for protein sequences. Results We found that 14mer peptides with amino acids represented as simply either hydrophobic or hydrophilic provided the best models for discrimination of E3 ligases from other effector proteins with a receiver-operator characteristic area under the curve (AUC) of 0.90. When considering a subset of E3 ubiquitin ligase effectors that do not fall into known sequence based families we found that the AUC was 0.82, demonstrating the effectiveness of our method at identifying novel functional family members. Feature selection was used to identify a parsimonious set of 10 RED peptides that provided good discrimination, and these peptides were found to be located in functionally important regions of the proteins involved in E2 and host target protein binding. Our general approach enables construction of models based on other effector functions. We used SIEVE-Ub to predict nine potential novel E3 ligases from a large set of bacterial genomes. SIEVE-Ub is available for download at https://doi.org/10.6084/m9.figshare.7766984.v1 or https://github.com/biodataganache/SIEVE-Ub for the most current version.
Collapse
Affiliation(s)
- Jason E McDermott
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States of America.,Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, United States of America
| | - John R Cort
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Ernesto S Nakayasu
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Jonathan N Pruneda
- Department of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, OR, United States of America
| | - Christopher Overall
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, United States of America
| | - Joshua N Adkins
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States of America
| |
Collapse
|
5
|
Lipid Droplets: A Significant but Understudied Contributor of Host⁻Bacterial Interactions. Cells 2019; 8:cells8040354. [PMID: 30991653 PMCID: PMC6523240 DOI: 10.3390/cells8040354] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 12/13/2022] Open
Abstract
Lipid droplets (LDs) are cytosolic lipid storage organelles that are important for cellular lipid metabolism, energy homeostasis, cell signaling, and inflammation. Several bacterial, viral and protozoal pathogens exploit host LDs to promote infection, thus emphasizing the importance of LDs at the host–pathogen interface. In this review, we discuss the thus far reported relation between host LDs and bacterial pathogens including obligate and facultative intracellular bacteria, and extracellular bacteria. Although there is less evidence for a LD–extracellular bacterial interaction compared to interactions with intracellular bacteria, in this review, we attempt to compare the bacterial mechanisms that target LDs, the host signaling pathways involved and the utilization of LDs by these bacteria. Many intracellular bacteria employ unique mechanisms to target host LDs and potentially obtain nutrients and lipids for vacuolar biogenesis and/or immune evasion. However, extracellular bacteria utilize LDs to either promote host tissue damage or induce host death. We also identify several areas that require further investigation. Along with identifying LD interactions with bacteria besides the ones reported, the precise mechanisms of LD targeting and how LDs benefit pathogens should be explored for the bacteria discussed in the review. Elucidating LD–bacterial interactions promises critical insight into a novel host–pathogen interaction.
Collapse
|
6
|
Farris TR, Zhu B, Wang JY, McBride JW. Ehrlichia chaffeensis TRP32 Nucleomodulin Function and Localization Is Regulated by NEDD4L-Mediated Ubiquitination. Front Cell Infect Microbiol 2018; 7:534. [PMID: 29376035 PMCID: PMC5768648 DOI: 10.3389/fcimb.2017.00534] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Accepted: 12/22/2017] [Indexed: 12/13/2022] Open
Abstract
Ehrlichia chaffeensis is an obligately intracellular bacterium that reprograms the mononuclear phagocyte through diverse effector-host interactions to modulate various host cell processes. In a previous study, we reported that the E. chaffeensis nucleomodulin TRP32 regulates transcription of host genes in several biologically relevant categories, including cell differentiation and proliferation. In this study, we investigate the effect of ubiquitination on TRP32 function and localization within the host cell. TRP32 is both mono- and polyubiquitinated on multiple lysine residues during infection and when ectopically expressed. Despite lacking a canonical PPxY motif, TRP32 interacted with, and was modified by the human HECT E3 ubiquitin (Ub) ligase NEDD4L. TRP32 ubiquitination was not by K48-linked polyUb chains, nor was it degraded by the proteasome; however, TRP32 was modified by K63-linked polyUb chains detected both in the cytosol and nucleus. HECT ligase inhibitor, heclin, altered the subnuclear localization of ectopically expressed TRP32 from a diffuse nuclear pattern to a lacy, punctate pattern with TRP32 distributed around the periphery of the nucleus and nucleoli. When a TRP32 lysine null (K-null) mutant was ectopically expressed, it exhibited a similar phenotype as single lysine mutants (K63R, K93R, and K123R). However, the K-null mutant showed increased amounts of cytoplasmic TRP32 compared to single lysine mutants or heclin-treated cells ectopically expressing TRP32. These alterations in localization corresponded to changes in TRP32 transcriptional repressor function with heclin-treated and single lysine mutants unable to repress transcription of a TRP32 target genes in a luciferase assay.
Collapse
Affiliation(s)
- Tierra R Farris
- Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States
| | - Bing Zhu
- Pathology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jennifer Y Wang
- Cell Biology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jere W McBride
- Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, United States.,Pathology, University of Texas Medical Branch, Galveston, TX, United States.,Cell Biology, University of Texas Medical Branch, Galveston, TX, United States.,Center for Biodefense and Emerging Infectious Diseases, University of Texas Medical Branch, Galveston, TX, United States.,Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX, United States.,Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, United States
| |
Collapse
|
7
|
Abstract
ExoU is a type III-secreted cytotoxin expressing A2 phospholipase activity when injected into eukaryotic target cells by the bacterium Pseudomonas aeruginosa The enzymatic activity of ExoU is undetectable in vitro unless ubiquitin, a required cofactor, is added to the reaction. The role of ubiquitin in facilitating ExoU enzymatic activity is poorly understood but of significance for designing inhibitors to prevent tissue injury during infections with strains of P. aeruginosa producing this toxin. Most ubiquitin-binding proteins, including ExoU, demonstrate a low (micromolar) affinity for monoubiquitin (monoUb). Additionally, ExoU is a large and dynamic protein, limiting the applicability of traditional structural techniques such as NMR and X-ray crystallography to define this protein-protein interaction. Recent advancements in computational methods, however, have allowed high-resolution protein modeling using sparse data. In this study, we combine double electron-electron resonance (DEER) spectroscopy and Rosetta modeling to identify potential binding interfaces of ExoU and monoUb. The lowest-energy scoring model was tested using biochemical, biophysical, and biological techniques. To verify the binding interface, Rosetta was used to design a panel of mutations to modulate binding, including one variant with enhanced binding affinity. Our analyses show the utility of computational modeling when combined with sensitive biological assays and biophysical approaches that are exquisitely suited for large dynamic proteins.
Collapse
|
8
|
Candido-Ferreira IL, Kronenberger T, Sayegh RSR, Batista IDFC, da Silva Junior PI. Evidence of an Antimicrobial Peptide Signature Encrypted in HECT E3 Ubiquitin Ligases. Front Immunol 2017; 7:664. [PMID: 28119686 PMCID: PMC5220581 DOI: 10.3389/fimmu.2016.00664] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/16/2016] [Indexed: 12/11/2022] Open
Abstract
The ubiquitin-proteasome pathway (UPP) is a hallmark of the eukaryotic cell. In jawed vertebrates, it has been co-opted by the adaptive immune system, where proteasomal degradation produces endogenous peptides for major histocompatibility complex class I antigen presentation. However, proteolytic products are also necessary for the phylogenetically widespread innate immune system, as they often play a role as host defense peptides (HDPs), pivotal effectors against pathogens. Here, we report the identification of the arachnid HDP oligoventin, which shares homology to a core member of the UPP, E3 ubiquitin ligases. Oligoventin has broad antimicrobial activity and shows strong synergy with lysozymes. Using computational and phylogenetic approaches, we show high conservation of the oligoventin signature in HECT E3s. In silico simulation of HECT E3s self-proteolysis provides evidence that HDPs can be generated by fine-tuned 26S proteasomal degradation, and therefore are consistent with the hypothesis that oligoventin is a cryptic peptide released by the proteolytic processing of an Nedd4 E3 precursor protein. Finally, we compare the production of HDPs and endogenous antigens from orthologous HECT E3s by proteasomal degradation as a means of analyzing the UPP coupling to metazoan immunity. Our results highlight the functional plasticity of the UPP in innate and adaptive immune systems as a possibly recurrent mechanism to generate functionally diverse peptides.
Collapse
Affiliation(s)
- Ivan Lavander Candido-Ferreira
- Special Laboratory for Applied Toxinology (LETA), Center of Toxins, Immune-Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, São Paulo, Brazil; Biosciences Institute, University of São Paulo, São Paulo, São Paulo, Brazil
| | - Thales Kronenberger
- Department of Parasitology, Biomedical Sciences Institute, University of São Paulo , São Paulo, São Paulo , Brazil
| | - Raphael Santa Rosa Sayegh
- Special Laboratory for Applied Toxinology (LETA), Center of Toxins, Immune-Response and Cell Signaling (CeTICS), Butantan Institute, São Paulo, São Paulo, Brazil; Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, São Paulo, Brazil
| | | | - Pedro Ismael da Silva Junior
- Special Laboratory for Applied Toxinology (LETA), Center of Toxins, Immune-Response and Cell Signaling (CeTICS), Butantan Institute , São Paulo, São Paulo , Brazil
| |
Collapse
|
9
|
Nelson MS, Chun CL, Sadowsky MJ. Type IV Effector Proteins Involved in the Medicago-Sinorhizobium Symbiosis. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2017; 30:28-34. [PMID: 27918247 DOI: 10.1094/mpmi-10-16-0211-r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In this study, we investigated genetic elements of the type IV secretion system (T4SS) found in Sinorhizobium spp. and the role they play in symbiosis. Sinorhizobium meliloti and S. medicae each contain a putative T4SS similar to that used by Agrobacterium tumefaciens during pathogenesis. The Cre reporter assay for translocation system was used to validate potential effector proteins. Both S. meliloti and S. medicae contained the effector protein TfeA, which was translocated into the host plant. Sequence analysis revealed the presence of a nod box involved in transcriptional activation of symbiosis-related genes, upstream of the transcriptional regulator (virG) in the Sinorhizobium T4SS. Replicate quantitative reverse transcription-polymerase chain reaction analyses indicated that luteolin, released by roots and seeds of Medicago truncatula, upregulated transcription of tfeA and virG. Mutations in the T4SS apparatus or tfeA alone resulted in reduced numbers of nodules formed on M. truncatula genotypes. In addition, S. meliloti KH46c, which contains a deletion in the T4SS, was less competitive for nodule formation when coinoculated with an equal number of cells of the wild-type strain. To our knowledge, TfeA is the first T4SS effector protein identified in Sinorhizobium spp. Our results indicate that Sinorhizobium i) uses a T4SS during initiation of symbiosis with Medicago spp., and ii) alters Medicago cells in planta during symbiosis. This study also offers additional bioinformatic evidence that several different rhizobial species may use the T4SS in symbiosis with other legumes.
Collapse
Affiliation(s)
| | | | - Michael J Sadowsky
- 1 Biotechnology Institute
- 3 Department of Soil Water & Climate, University of Minnesota, St. Paul, MN, U.S.A
| |
Collapse
|
10
|
Bao Z, Meng F, Strickler SR, Dunham DM, Munkvold KR, Martin GB. Identification of a Candidate Gene in Solanum habrochaites for Resistance to a Race 1 Strain of Pseudomonas syringae pv. tomato. THE PLANT GENOME 2015; 8:eplantgenome2015.02.0006. [PMID: 33228271 DOI: 10.3835/plantgenome2015.02.0006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 09/01/2015] [Indexed: 06/11/2023]
Abstract
Bacterial speck disease caused by Pseudomonas syringae pv. tomato (Pst) is a persistent problem on tomato (Solanum lycopersicum L.). Resistance against race 0 Pst strains is conferred by the Pto protein, which recognizes either of two pathogen effectors: AvrPto or AvrPtoB. However, current tomato varieties do not have resistance to the increasingly common race 1 strains, which lack these effectors. We identified accessions of Solanum habrochaites S. Knapp & D. M. Spooner that are resistant to the race 1 strain T1. Genome sequence comparisons of T1 and two Pst strains that are virulent on these accessions suggested that known microbe-associated molecular patterns (MAMPs) or effectors are not involved in the resistance. We developed an F2 population from a cross between one T1-resistant accession, LA2109, and a susceptible tomato cultivar to investigate the genetic basis of this resistance. Linkage analysis using whole-genome sequence of 58 F2 plants identified quantitative trait loci (QTL), qRph1, in a 5.8-Mb region on chromosome 2, and qRph2, in a 52.4-Mb region on chromosome 8, which account for 24 and 26% of the phenotypic variability, respectively. High-resolution mapping of qRph1 confirmed it contributed to T1 resistance and delimited it to a 1060-kb region containing 139 genes, including three encoding receptor-like proteins (RLPs) and 17 encoding receptor-like protein kinases (RLKs). One RLK gene, Solyc02g072470, is a promising candidate for qRph1, as it is highly expressed in LA2109 and induced on treatment with MAMPs. qRph1 might be useful for enhancing resistance to race 1 strains and its future characterization could provide insights into the plant immune system.
Collapse
Affiliation(s)
- Zhilong Bao
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853
| | - Fanhong Meng
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853
| | | | - Diane M Dunham
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853
| | | | - Gregory B Martin
- Boyce Thompson Institute for Plant Research, Ithaca, NY, 14853
- Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell Univ., Ithaca, NY, 14853
| |
Collapse
|
11
|
Memišević V, Zavaljevski N, Rajagopala SV, Kwon K, Pieper R, DeShazer D, Reifman J, Wallqvist A. Mining host-pathogen protein interactions to characterize Burkholderia mallei infectivity mechanisms. PLoS Comput Biol 2015; 11:e1004088. [PMID: 25738731 PMCID: PMC4349708 DOI: 10.1371/journal.pcbi.1004088] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 12/15/2014] [Indexed: 01/01/2023] Open
Abstract
Burkholderia pathogenicity relies on protein virulence factors to control and promote bacterial internalization, survival, and replication within eukaryotic host cells. We recently used yeast two-hybrid (Y2H) screening to identify a small set of novel Burkholderia proteins that were shown to attenuate disease progression in an aerosol infection animal model using the virulent Burkholderia mallei ATCC 23344 strain. Here, we performed an extended analysis of primarily nine B. mallei virulence factors and their interactions with human proteins to map out how the bacteria can influence and alter host processes and pathways. Specifically, we employed topological analyses to assess the connectivity patterns of targeted host proteins, identify modules of pathogen-interacting host proteins linked to processes promoting infectivity, and evaluate the effect of crosstalk among the identified host protein modules. Overall, our analysis showed that the targeted host proteins generally had a large number of interacting partners and interacted with other host proteins that were also targeted by B. mallei proteins. We also introduced a novel Host-Pathogen Interaction Alignment (HPIA) algorithm and used it to explore similarities between host-pathogen interactions of B. mallei, Yersinia pestis, and Salmonella enterica. We inferred putative roles of B. mallei proteins based on the roles of their aligned Y. pestis and S. enterica partners and showed that up to 73% of the predicted roles matched existing annotations. A key insight into Burkholderia pathogenicity derived from these analyses of Y2H host-pathogen interactions is the identification of eukaryotic-specific targeted cellular mechanisms, including the ubiquitination degradation system and the use of the focal adhesion pathway as a fulcrum for transmitting mechanical forces and regulatory signals. This provides the mechanisms to modulate and adapt the host-cell environment for the successful establishment of host infections and intracellular spread. Burkholderia species need to manipulate many host processes and pathways in order to establish a successful intracellular infection in eukaryotic host organisms. Burkholderia mallei uses secreted virulence factor proteins as a means to execute host-pathogen interactions and promote pathogenesis. While validated virulence factor proteins have been shown to attenuate infection in animal models, their actual roles in modifying and influencing host processes are not well understood. Here, we used host-pathogen protein-protein interactions derived from yeast two-hybrid screens to study nine known B. mallei virulence factors and map out potential virulence mechanisms. From the data, we derived both general and specific insights into Burkholderia host-pathogen infectivity pathways. We showed that B. mallei virulence factors tended to target multifunctional host proteins, proteins that interacted with each other, and host proteins with a large number of interacting partners. We also identified similarities between host-pathogen interactions of B. mallei, Yersinia pestis, and Salmonella enterica using a novel host-pathogen interactions alignment algorithm. Importantly, our data are compatible with a framework in which multiple B. mallei virulence factors broadly influence key host processes related to ubiquitin-mediated proteolysis and focal adhesion. This provides B. mallei the means to modulate and adapt the host-cell environment to advance infection.
Collapse
Affiliation(s)
- Vesna Memišević
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland, United States of America
| | - Nela Zavaljevski
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland, United States of America
| | | | - Keehwan Kwon
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - Rembert Pieper
- J. Craig Venter Institute, Rockville, Maryland, United States of America
| | - David DeShazer
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, United States of America
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland, United States of America
- * E-mail:
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland, United States of America
| |
Collapse
|
12
|
Abstract
Inhibition of apoptotic death of macrophages by Mycobacterium tuberculosis represents an important mechanism of virulence that results in pathogen survival both in vitro and in vivo. To identify M. tuberculosis virulence determinants involved in the modulation of apoptosis, we previously screened a transposon bank of mutants in human macrophages, and an M. tuberculosis clone with a nonfunctional Rv3354 gene was identified as incompetent to suppress apoptosis. Here, we show that the Rv3354 gene encodes a protein kinase that is secreted within mononuclear phagocytic cells and is required for M. tuberculosis virulence. The Rv3354 effector targets the metalloprotease (JAMM) domain within subunit 5 of the COP9 signalosome (CSN5), resulting in suppression of apoptosis and in the destabilization of CSN function and regulatory cullin-RING ubiquitin E3 enzymatic activity. Our observation suggests that alteration of the metalloprotease activity of CSN by Rv3354 possibly prevents the ubiquitin-dependent proteolysis of M. tuberculosis-secreted proteins. IMPORTANCE : Macrophage protein degradation is regulated by a protein complex called a signalosome. One of the signalosomes associated with activation of ubiquitin and protein labeling for degradation was found to interact with a secreted protein from M. tuberculosis, which binds to the complex and inactivates it. The interference with the ability to inactivate bacterial proteins secreted in the phagocyte cytosol may have crucial importance for bacterial survival within the phagocyte.
Collapse
|
13
|
Affiliation(s)
- Jon Huibregtse
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - John R. Rohde
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
- * E-mail:
| |
Collapse
|
14
|
Bakowski MA, Desjardins CA, Smelkinson MG, Dunbar TA, Lopez-Moyado IF, Rifkin SA, Cuomo CA, Troemel ER. Ubiquitin-mediated response to microsporidia and virus infection in C. elegans. PLoS Pathog 2014; 10:e1004200. [PMID: 24945527 PMCID: PMC4063957 DOI: 10.1371/journal.ppat.1004200] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 05/07/2014] [Indexed: 11/18/2022] Open
Abstract
Microsporidia comprise a phylum of over 1400 species of obligate intracellular pathogens that can infect almost all animals, but little is known about the host response to these parasites. Here we use the whole-animal host C. elegans to show an in vivo role for ubiquitin-mediated response to the microsporidian species Nematocida parisii, as well to the Orsay virus, another natural intracellular pathogen of C. elegans. We analyze gene expression of C. elegans in response to N. parisii, and find that it is similar to response to viral infection. Notably, we find an upregulation of SCF ubiquitin ligase components, such as the cullin ortholog cul-6, which we show is important for ubiquitin targeting of N. parisii cells in the intestine. We show that ubiquitylation components, the proteasome, and the autophagy pathway are all important for defense against N. parisii infection. We also find that SCF ligase components like cul-6 promote defense against viral infection, where they have a more robust role than against N. parisii infection. This difference may be due to suppression of the host ubiquitylation system by N. parisii: when N. parisii is crippled by anti-microsporidia drugs, the host can more effectively target pathogen cells for ubiquitylation. Intriguingly, inhibition of the ubiquitin-proteasome system (UPS) increases expression of infection-upregulated SCF ligase components, indicating that a trigger for transcriptional response to intracellular infection by N. parisii and virus may be perturbation of the UPS. Altogether, our results demonstrate an in vivo role for ubiquitin-mediated defense against microsporidian and viral infections in C. elegans.
Collapse
Affiliation(s)
- Malina A. Bakowski
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
| | | | - Margery G. Smelkinson
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
| | - Tiffany A. Dunbar
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
| | - Isaac F. Lopez-Moyado
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, California, United States of America
| | - Scott A. Rifkin
- Bioinformatics and Systems Biology Graduate Program, University of California San Diego, La Jolla, California, United States of America
- Division of Biological Sciences, Section of Ecology, Behavior, and Evolution University of California San Diego, La Jolla, California, United States of America
| | - Christina A. Cuomo
- The Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States of America
| | - Emily R. Troemel
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
15
|
MacLean AM, Orlovskis Z, Kowitwanich K, Zdziarska AM, Angenent GC, Immink RGH, Hogenhout SA. Phytoplasma effector SAP54 hijacks plant reproduction by degrading MADS-box proteins and promotes insect colonization in a RAD23-dependent manner. PLoS Biol 2014; 12:e1001835. [PMID: 24714165 PMCID: PMC3979655 DOI: 10.1371/journal.pbio.1001835] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 02/28/2014] [Indexed: 12/19/2022] Open
Abstract
Pathogens that rely upon multiple hosts to complete their life cycles often modify behavior and development of these hosts to coerce them into improving pathogen fitness. However, few studies describe mechanisms underlying host coercion. In this study, we elucidate the mechanism by which an insect-transmitted pathogen of plants alters floral development to convert flowers into vegetative tissues. We find that phytoplasma produce a novel effector protein (SAP54) that interacts with members of the MADS-domain transcription factor (MTF) family, including key regulators SEPALLATA3 and APETALA1, that occupy central positions in the regulation of floral development. SAP54 mediates degradation of MTFs by interacting with proteins of the RADIATION SENSITIVE23 (RAD23) family, eukaryotic proteins that shuttle substrates to the proteasome. Arabidopsis rad23 mutants do not show conversion of flowers into leaf-like tissues in the presence of SAP54 and during phytoplasma infection, emphasizing the importance of RAD23 to the activity of SAP54. Remarkably, plants with SAP54-induced leaf-like flowers are more attractive for colonization by phytoplasma leafhopper vectors and this colonization preference is dependent on RAD23. An effector that targets and suppresses flowering while simultaneously promoting insect herbivore colonization is unprecedented. Moreover, RAD23 proteins have, to our knowledge, no known roles in flower development, nor plant defence mechanisms against insects. Thus SAP54 generates a short circuit between two key pathways of the host to alter development, resulting in sterile plants, and promotes attractiveness of these plants to leafhopper vectors helping the obligate phytoplasmas reproduce and propagate (zombie plants).
Collapse
Affiliation(s)
- Allyson M. MacLean
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, Norfolk, United Kingdom
| | - Zigmunds Orlovskis
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, Norfolk, United Kingdom
| | - Krissana Kowitwanich
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, Norfolk, United Kingdom
| | - Anna M. Zdziarska
- Bioscience, Plant Research International, Wageningen, The Netherlands
| | - Gerco C. Angenent
- Bioscience, Plant Research International, Wageningen, The Netherlands
- Laboratory of Molecular Biology, Wageningen University, Wageningen, The Netherlands
| | | | - Saskia A. Hogenhout
- Department of Cell and Developmental Biology, John Innes Centre, Norwich Research Park, Norwich, Norfolk, United Kingdom
| |
Collapse
|
16
|
Jayamani E, Mylonakis E. Effector triggered manipulation of host immune response elicited by different pathotypes of Escherichia coli. Virulence 2014; 5:733-9. [PMID: 25513774 PMCID: PMC4189879 DOI: 10.4161/viru.29948] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 07/08/2014] [Accepted: 07/15/2014] [Indexed: 12/28/2022] Open
Abstract
Effectors are virulence factors that are secreted by bacteria during an infection in order to subvert cellular processes or induce the surveillance system of the host. Pathogenic microorganisms encode effectors, toxins and components of secretion systems that inject the effectors to the host. Escherichia coli is part of the innocuous commensal microbial flora of the gastrointestinal tract. However, pathogenic E. coli can cause diarrheal and extraintestinal diseases. Pathogenic E. coli uses secretion systems to inject an array of effector proteins directly into the host cells. Herein, we discuss the effectors secreted by different pathotypes of E. coli and provide an overview of strategies employed by effectors to target the host cellular and subcellular processes as well as their role in triggering host immune response.
Collapse
Affiliation(s)
- Elamparithi Jayamani
- Division of Infectious Diseases; Rhode Island Hospital; Alpert Medical School of Brown University; Providence, RI USA
| | - Eleftherios Mylonakis
- Division of Infectious Diseases; Rhode Island Hospital; Alpert Medical School of Brown University; Providence, RI USA
| |
Collapse
|
17
|
Audia JP, Lindsey AS, Housley NA, Ochoa CR, Zhou C, Toba M, Oka M, Annamdevula NS, Fitzgerald MS, Frank DW, Alvarez DF. In the absence of effector proteins, the Pseudomonas aeruginosa type three secretion system needle tip complex contributes to lung injury and systemic inflammatory responses. PLoS One 2013; 8:e81792. [PMID: 24312357 PMCID: PMC3842252 DOI: 10.1371/journal.pone.0081792] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Accepted: 10/16/2013] [Indexed: 01/06/2023] Open
Abstract
Herein we describe a pathogenic role for the Pseudomonas aeruginosa type three secretion system (T3SS) needle tip complex protein, PcrV, in causing lung endothelial injury. We first established a model in which P. aeruginosa wild type strain PA103 caused pneumonia-induced sepsis and distal organ dysfunction. Interestingly, a PA103 derivative strain lacking its two known secreted effectors, ExoU and ExoT [denoted PA103 (ΔU/ΔT)], also caused sepsis and modest distal organ injury whereas an isogenic PA103 strain lacking the T3SS needle tip complex assembly protein [denoted PA103 (ΔPcrV)] did not. PA103 (ΔU/ΔT) infection caused neutrophil influx into the lung parenchyma, lung endothelial injury, and distal organ injury (reminiscent of sepsis). In contrast, PA103 (ΔPcrV) infection caused nominal neutrophil infiltration and lung endothelial injury, but no distal organ injury. We further examined pathogenic mechanisms of the T3SS needle tip complex using cultured rat pulmonary microvascular endothelial cells (PMVECs) and revealed a two-phase, temporal nature of infection. At 5-hours post-inoculation (early phase infection), PA103 (ΔU/ΔT) elicited PMVEC barrier disruption via perturbation of the actin cytoskeleton and did so in a cell death-independent manner. Conversely, PA103 (ΔPcrV) infection did not elicit early phase PMVEC barrier disruption. At 24-hours post-inoculation (late phase infection), PA103 (ΔU/ΔT) induced PMVEC damage and death that displayed an apoptotic component. Although PA103 (ΔPcrV) infection induced late phase PMVEC damage and death, it did so to an attenuated extent. The PA103 (ΔU/ΔT) and PA103 (ΔPcrV) mutants grew at similar rates and were able to adhere equally to PMVECs post-inoculation indicating that the observed differences in damage and barrier disruption are likely attributable to T3SS needle tip complex-mediated pathogenic differences post host cell attachment. Together, these infection data suggest that the T3SS needle tip complex and/or another undefined secreted effector(s) are important determinants of P. aeruginosa pneumonia-induced lung endothelial barrier disruption.
Collapse
Affiliation(s)
- Jonathon P. Audia
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail: (JPA); (DFA)
| | - Ashley S. Lindsey
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Nicole A. Housley
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Courtney R. Ochoa
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Chun Zhou
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Michie Toba
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Masahiko Oka
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Naga S. Annamdevula
- Department of Chemical and Biomolecular Engineering, University of South Alabama, Mobile, Alabama, United States of America
| | - Meshann S. Fitzgerald
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
| | - Dara W. Frank
- Department of Microbiology and Molecular Genetics, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Diego F. Alvarez
- Department of Internal Medicine, University of South Alabama, Mobile, Alabama, United States of America
- Department of Pharmacology, University of South Alabama, Mobile, Alabama, United States of America
- Center for Lung Biology, University of South Alabama, Mobile, Alabama, United States of America
- * E-mail: (JPA); (DFA)
| |
Collapse
|
18
|
Memišević V, Zavaljevski N, Pieper R, Rajagopala SV, Kwon K, Townsend K, Yu C, Yu X, DeShazer D, Reifman J, Wallqvist A. Novel Burkholderia mallei virulence factors linked to specific host-pathogen protein interactions. Mol Cell Proteomics 2013; 12:3036-51. [PMID: 23800426 PMCID: PMC3820922 DOI: 10.1074/mcp.m113.029041] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 06/10/2013] [Indexed: 11/09/2022] Open
Abstract
Burkholderia mallei is an infectious intracellular pathogen whose virulence and resistance to antibiotics makes it a potential bioterrorism agent. Given its genetic origin as a commensal soil organism, it is equipped with an extensive and varied set of adapted mechanisms to cope with and modulate host-cell environments. One essential virulence mechanism constitutes the specialized secretion systems that are designed to penetrate host-cell membranes and insert pathogen proteins directly into the host cell's cytosol. However, the secretion systems' proteins and, in particular, their host targets are largely uncharacterized. Here, we used a combined in silico, in vitro, and in vivo approach to identify B. mallei proteins required for pathogenicity. We used bioinformatics tools, including orthology detection and ab initio predictions of secretion system proteins, as well as published experimental Burkholderia data to initially select a small number of proteins as putative virulence factors. We then used yeast two-hybrid assays against normalized whole human and whole murine proteome libraries to detect and identify interactions among each of these bacterial proteins and host proteins. Analysis of such interactions provided both verification of known virulence factors and identification of three new putative virulence proteins. We successfully created insertion mutants for each of these three proteins using the virulent B. mallei ATCC 23344 strain. We exposed BALB/c mice to mutant strains and the wild-type strain in an aerosol challenge model using lethal B. mallei doses. In each set of experiments, mice exposed to mutant strains survived for the 21-day duration of the experiment, whereas mice exposed to the wild-type strain rapidly died. Given their in vivo role in pathogenicity, and based on the yeast two-hybrid interaction data, these results point to the importance of these pathogen proteins in modulating host ubiquitination pathways, phagosomal escape, and actin-cytoskeleton rearrangement processes.
Collapse
Affiliation(s)
- Vesna Memišević
- From the ‡Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland 21702
| | - Nela Zavaljevski
- From the ‡Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland 21702
| | | | | | - Keehwan Kwon
- §J. Craig Venter Institute, Rockville, Maryland 20850
| | | | - Chenggang Yu
- From the ‡Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland 21702
| | - Xueping Yu
- From the ‡Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland 21702
| | - David DeShazer
- ¶Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland 21702
| | - Jaques Reifman
- From the ‡Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland 21702
| | - Anders Wallqvist
- From the ‡Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, Maryland 21702
| |
Collapse
|
19
|
Meyer DF, Noroy C, Moumène A, Raffaele S, Albina E, Vachiéry N. Searching algorithm for type IV secretion system effectors 1.0: a tool for predicting type IV effectors and exploring their genomic context. Nucleic Acids Res 2013; 41:9218-29. [PMID: 23945940 PMCID: PMC3814349 DOI: 10.1093/nar/gkt718] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Type IV effectors (T4Es) are proteins produced by pathogenic bacteria to manipulate host cell gene expression and processes, divert the cell machinery for their own profit and circumvent the immune responses. T4Es have been characterized for some bacteria but many remain to be discovered. To help biologists identify putative T4Es from the complete genome of α- and γ-proteobacteria, we developed a Perl-based command line bioinformatics tool called S4TE (searching algorithm for type-IV secretion system effectors). The tool predicts and ranks T4E candidates by using a combination of 13 sequence characteristics, including homology to known effectors, homology to eukaryotic domains, presence of subcellular localization signals or secretion signals, etc. S4TE software is modular, and specific motif searches are run independently before ultimate combination of the outputs to generate a score and sort the strongest T4Es candidates. The user keeps the possibility to adjust various searching parameters such as the weight of each module, the selection threshold or the input databases. The algorithm also provides a GC% and local gene density analysis, which strengthen the selection of T4E candidates. S4TE is a unique predicting tool for T4Es, finding its utility upstream from experimental biology.
Collapse
Affiliation(s)
- Damien F Meyer
- CIRAD, UMR CMAEE, F-97170 Petit-Bourg, Guadeloupe, France, INRA, UMR1309 CMAEE, F-34398, Montpellier, France, Université des Antilles et de la Guyane, 97159 Pointe-à-Pitre cedex, Guadeloupe, France, INRA, Laboratoire des Interactions Plantes-Microorganismes, UMR441, Castanet-Tolosan, France and CNRS, Laboratoire des Interactions Plantes-Microorganismes, UMR2594, Castanet-Tolosan, France
| | | | | | | | | | | |
Collapse
|
20
|
Anderson DM, Feix JB, Monroe AL, Peterson FC, Volkman BF, Haas AL, Frank DW. Identification of the major ubiquitin-binding domain of the Pseudomonas aeruginosa ExoU A2 phospholipase. J Biol Chem 2013; 288:26741-52. [PMID: 23908356 DOI: 10.1074/jbc.m113.478529] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Numerous Gram-negative bacterial pathogens use type III secretion systems to deliver effector molecules into the cytoplasm of a host cell. Many of these effectors have evolved to manipulate the host ubiquitin system to alter host cell physiology or the location, stability, or function of the effector itself. ExoU is a potent A2 phospholipase used by Pseudomonas aeruginosa to destroy membranes of infected cells. The enzyme is held in an inactive state inside of the bacterium due to the absence of a required eukaryotic activator, which was recently identified as ubiquitin. This study sought to identify the region of ExoU required to mediate this interaction and determine the properties of ubiquitin important for binding, ExoU activation, or both. Biochemical and biophysical approaches were used to map the ubiquitin-binding domain to a C-terminal four-helix bundle of ExoU. The hydrophobic patch of ubiquitin is required for full binding affinity and activation. Binding and activation were uncoupled by introducing an L8R substitution in ubiquitin. Purified L8R demonstrated a parental binding phenotype to ExoU but did not activate the phospholipase in vitro. Utilizing these new biochemical data and intermolecular distance measurements by double electron-electron resonance, we propose a model for an ExoU-monoubiquitin complex.
Collapse
Affiliation(s)
- David M Anderson
- From the Department of Microbiology and Molecular Genetics and the Center for Infectious Disease Research and
| | | | | | | | | | | | | |
Collapse
|
21
|
Pouring salt on a wound: Pseudomonas aeruginosa virulence factors alter Na+ and Cl- flux in the lung. J Bacteriol 2013; 195:4013-9. [PMID: 23836869 DOI: 10.1128/jb.00339-13] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Pseudomonas aeruginosa is a ubiquitous opportunistic pathogen with multiple niches in the human body, including the lung. P. aeruginosa infections are particularly damaging or fatal for patients with ventilator-associated pneumonia, chronic obstructive pulmonary disease, and cystic fibrosis (CF). To establish an infection, P. aeruginosa relies on a suite of virulence factors, including lipopolysaccharide, phospholipases, exoproteases, phenazines, outer membrane vesicles, type III secreted effectors, flagella, and pili. These factors not only damage the epithelial cell lining but also induce changes in cell physiology and function such as cell shape, membrane permeability, and protein synthesis. While such virulence factors are important in initial infection, many become dysregulated or nonfunctional during the course of chronic infection. Recent work on the virulence factors alkaline protease (AprA) and CF transmembrane conductance regulator inhibitory factor (Cif) show that P. aeruginosa also perturbs epithelial ion transport and osmosis, which may be important for the long-term survival of this microbe in the lung. Here we discuss the literature regarding host physiology-altering virulence factors with a focus on Cif and AprA and their potential roles in chronic infection and immune evasion.
Collapse
|
22
|
Duda DM, Olszewski JL, Schuermann JP, Kurinov I, Miller DJ, Nourse A, Alpi AF, Schulman BA. Structure of HHARI, a RING-IBR-RING ubiquitin ligase: autoinhibition of an Ariadne-family E3 and insights into ligation mechanism. Structure 2013; 21:1030-41. [PMID: 23707686 DOI: 10.1016/j.str.2013.04.019] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 04/25/2013] [Accepted: 04/29/2013] [Indexed: 12/20/2022]
Abstract
A distinct mechanism for ubiquitin (Ub) ligation has recently been proposed for the RING1-IBR-RING2 (RBR) family of E3s: an N-terminal RING1 domain recruits a thioester-linked intermediate complex between Ub and the E2 UbcH7, and a structurally distinct C-terminal RING2 domain displays a catalytic cysteine required for Ub ligation. To obtain insights into RBR E3s, we determined the crystal structure of the human homolog of Ariadne (HHARI), which reveals the individual RING1, IBR, and RING2 domains embedded in superdomains involving sequences specific to the Ariadne RBR subfamily. The central IBR is flanked on one side by RING1, which is exposed and binds UbcH7. On the other side, a C-terminal autoinhibitory "Ariadne domain" masks the RING2 active site. Insights into RBR E3 mechanisms are provided by structure-based mutations that indicate distinct steps of relief from autoinhibition, Ub transfer from E2 to HHARI, and ligation from the HHARI cysteine to a terminal acceptor.
Collapse
Affiliation(s)
- David M Duda
- Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | | | | | | | | | | | | | | |
Collapse
|
23
|
Structural basis of eukaryotic cell targeting by type III secretion system (T3SS) effectors. Res Microbiol 2013; 164:605-19. [PMID: 23541478 DOI: 10.1016/j.resmic.2013.03.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 02/27/2013] [Indexed: 02/06/2023]
Abstract
Type III secretion systems (T3SS) are macromolecular complexes that translocate a wide number of effector proteins into eukaryotic host cells. Once within the cytoplasm, many T3SS effectors mimic the structure and/or function of eukaryotic proteins in order to manipulate signaling cascades, and thus play pivotal roles in colonization, invasion, survival and virulence. Structural biology techniques have played key roles in the unraveling of bacterial strategies employed for mimicry and targeting. This review provides an overall view of our current understanding of structure and function of T3SS effectors, as well as of the different classes of eukaryotic proteins that are targeted and the consequences for the infected cell.
Collapse
|