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Yang X, Wei R, Liu H, Wei T, Zeng P, Cheung YC, Heng H, Chan EW, Li X, Chen S. Discovery of a Monoclonal Antibody That Targets Cell-Surface Pseudaminic Acid of Acinetobacter baumannii with Direct Bactericidal Effect. ACS CENTRAL SCIENCE 2024; 10:439-446. [PMID: 38435534 PMCID: PMC10906240 DOI: 10.1021/acscentsci.3c01507] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 03/05/2024]
Abstract
The therapeutic effects of antibodies include neutralization of pathogens, activation of the host complement system, and facilitation of phagocytosis of pathogens. However, antibody alone has never been shown to exhibit bactericidal activity. In this study, we developed a monoclonal antibody that targets the bacterial cell surface component Pseudaminic acid (Pse). This monoclonal antibody, Pse-MAB1, exhibited direct bactericidal activity on Acinetobacter baumannii strains, even in the absence of the host complements or other immune factors, and was able to confer a protective effect against A. baumannii infections in mice. This study provides new insight into the potential of developing monoclonal antibody-based antimicrobial therapy of multidrug resistant bacterial infections, especially those which occurred among immunocompromised patients.
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Affiliation(s)
- Xuemei Yang
- State
Key Lab of Chemical Biology and Drug Discovery and the Department
of Food Science and Nutrition, The Hong
Kong Polytechnic University, Hung Hom 999077, Hong Kong SAR
- Shenzhen
Key lab for Food Biological Safety Control, The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
| | - Ruohan Wei
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, Hong Kong SAR
| | - Han Liu
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, Hong Kong SAR
| | - Tongyao Wei
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, Hong Kong SAR
| | - Ping Zeng
- School
of Pharmacy, Faculty of Medicine, The Chinese
University of Hong Kong, Shatin 999077, Hong Kong
SAR
| | - Yan Chu Cheung
- State
Key Lab of Chemical Biology and Drug Discovery and the Department
of Food Science and Nutrition, The Hong
Kong Polytechnic University, Hung Hom 999077, Hong Kong SAR
- Department
of Infectious Diseases and Public Health, Jockey Club College of Veterinary
Medicine and Life Sciences, City University
of Hong Kong, Kowloon
Tong 999077, Hong Kong SAR
| | - Heng Heng
- State
Key Lab of Chemical Biology and Drug Discovery and the Department
of Food Science and Nutrition, The Hong
Kong Polytechnic University, Hung Hom 999077, Hong Kong SAR
- Department
of Infectious Diseases and Public Health, Jockey Club College of Veterinary
Medicine and Life Sciences, City University
of Hong Kong, Kowloon
Tong 999077, Hong Kong SAR
| | - Edward Waichi Chan
- Shenzhen
Key lab for Food Biological Safety Control, The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
| | - Xuechen Li
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong 999077, Hong Kong SAR
| | - Sheng Chen
- State
Key Lab of Chemical Biology and Drug Discovery and the Department
of Food Science and Nutrition, The Hong
Kong Polytechnic University, Hung Hom 999077, Hong Kong SAR
- Shenzhen
Key lab for Food Biological Safety Control, The Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen 518000, China
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2
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Aminov R, Aminova L. The role of the glycome in symbiotic host-microbe interactions. Glycobiology 2023; 33:1106-1116. [PMID: 37741057 PMCID: PMC10876039 DOI: 10.1093/glycob/cwad073] [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: 01/16/2023] [Revised: 09/13/2023] [Accepted: 09/21/2023] [Indexed: 09/25/2023] Open
Abstract
Glycosylation plays a crucial role in many aspects of cell biology, including cellular and organismal integrity, structure-and-function of many glycosylated molecules in the cell, signal transduction, development, cancer, and in a number of diseases. Besides, at the inter-organismal level of interaction, a variety of glycosylated molecules are involved in the host-microbiota recognition and initiation of downstream signalling cascades depending on the outcomes of the glycome-mediated ascertainment. The role of glycosylation in host-microbe interactions is better elaborated within the context of virulence and pathogenicity in bacterial infection processes but the symbiotic host-microbe relationships also involve substantive glycome-mediated interactions. The works in the latter field have been reviewed to a much lesser extent, and the main aim of this mini-review is to compensate for this deficiency and summarise the role of glycomics in host-microbe symbiotic interactions.
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Affiliation(s)
- Rustam Aminov
- The School of Medicine, Medical Sciences and Nutrition, Foresterhill Campus, Aberdeen AB25 2ZD, Scotland, United Kingdom
| | - Leila Aminova
- Midwest Bioprocessing Center, 801 W Main St, Peoria, IL, 61606-1877, United States
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3
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Pinho SS, Alves I, Gaifem J, Rabinovich GA. Immune regulatory networks coordinated by glycans and glycan-binding proteins in autoimmunity and infection. Cell Mol Immunol 2023; 20:1101-1113. [PMID: 37582971 PMCID: PMC10541879 DOI: 10.1038/s41423-023-01074-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 07/26/2023] [Indexed: 08/17/2023] Open
Abstract
The immune system is coordinated by an intricate network of stimulatory and inhibitory circuits that regulate host responses against endogenous and exogenous insults. Disruption of these safeguard and homeostatic mechanisms can lead to unpredictable inflammatory and autoimmune responses, whereas deficiency of immune stimulatory pathways may orchestrate immunosuppressive programs that contribute to perpetuate chronic infections, but also influence cancer development and progression. Glycans have emerged as essential components of homeostatic circuits, acting as fine-tuners of immunological responses and potential molecular targets for manipulation of immune tolerance and activation in a wide range of pathologic settings. Cell surface glycans, present in cells, tissues and the extracellular matrix, have been proposed to serve as "self-associated molecular patterns" that store structurally relevant biological data. The responsibility of deciphering this information relies on different families of glycan-binding proteins (including galectins, siglecs and C-type lectins) which, upon recognition of specific carbohydrate structures, can recalibrate the magnitude, nature and fate of immune responses. This process is tightly regulated by the diversity of glycan structures and the establishment of multivalent interactions on cell surface receptors and the extracellular matrix. Here we review the spatiotemporal regulation of selected glycan-modifying processes including mannosylation, complex N-glycan branching, core 2 O-glycan elongation, LacNAc extension, as well as terminal sialylation and fucosylation. Moreover, we illustrate examples that highlight the contribution of these processes to the control of immune responses and their integration with canonical tolerogenic pathways. Finally, we discuss the power of glycans and glycan-binding proteins as a source of immunomodulatory signals that could be leveraged for the treatment of autoimmune inflammation and chronic infection.
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Affiliation(s)
- Salomé S Pinho
- i3S - Institute for Research and Innovation in Health, University of Porto, 4200-135, Porto, Portugal.
- ICBAS-School of Medicine and Biomedical Sciences, University of Porto, 4050-313, Porto, Portugal.
- Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal.
| | - Inês Alves
- i3S - Institute for Research and Innovation in Health, University of Porto, 4200-135, Porto, Portugal
| | - Joana Gaifem
- i3S - Institute for Research and Innovation in Health, University of Porto, 4200-135, Porto, Portugal
| | - Gabriel A Rabinovich
- Laboratorio de Glicomedicina, Instituto de Biología y Medicina Experimental (IBYME), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), C1428, Ciudad de Buenos Aires, Argentina.
- Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, C1428, Ciudad de Buenos Aires, Argentina.
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4
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Kemper L, Hensel A. Campylobacter jejuni: targeting host cells, adhesion, invasion, and survival. Appl Microbiol Biotechnol 2023; 107:2725-2754. [PMID: 36941439 PMCID: PMC10027602 DOI: 10.1007/s00253-023-12456-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 03/23/2023]
Abstract
Campylobacter jejuni, causing strong enteritis, is an unusual bacterium with numerous peculiarities. Chemotactically controlled motility in viscous milieu allows targeted navigation to intestinal mucus and colonization. By phase variation, quorum sensing, extensive O-and N-glycosylation and use of the flagellum as type-3-secretion system C. jejuni adapts effectively to environmental conditions. C. jejuni utilizes proteases to open cell-cell junctions and subsequently transmigrates paracellularly. Fibronectin at the basolateral side of polarized epithelial cells serves as binding site for adhesins CadF and FlpA, leading to intracellular signaling, which again triggers membrane ruffling and reduced host cell migration by focal adhesion. Cell contacts of C. jejuni results in its secretion of invasion antigens, which induce membrane ruffling by paxillin-independent pathway. In addition to fibronectin-binding proteins, other adhesins with other target structures and lectins and their corresponding sugar structures are involved in host-pathogen interaction. Invasion into the intestinal epithelial cell depends on host cell structures. Fibronectin, clathrin, and dynein influence cytoskeletal restructuring, endocytosis, and vesicular transport, through different mechanisms. C. jejuni can persist over a 72-h period in the cell. Campylobacter-containing vacuoles, avoid fusion with lysosomes and enter the perinuclear space via dynein, inducing signaling pathways. Secretion of cytolethal distending toxin directs the cell into programmed cell death, including the pyroptotic release of proinflammatory substances from the destroyed cell compartments. The immune system reacts with an inflammatory cascade by participation of numerous immune cells. The development of autoantibodies, directed not only against lipooligosaccharides, but also against endogenous gangliosides, triggers autoimmune diseases. Lesions of the epithelium result in loss of electrolytes, water, and blood, leading to diarrhea, which flushes out mucus containing C. jejuni. Together with the response of the immune system, this limits infection time. Based on the structural interactions between host cell and bacterium, the numerous virulence mechanisms, signaling, and effects that characterize the infection process of C. jejuni, a wide variety of targets for attenuation of the pathogen can be characterized. The review summarizes strategies of C. jejuni for host-pathogen interaction and should stimulate innovative research towards improved definition of targets for future drug development. KEY POINTS: • Bacterial adhesion of Campylobacter to host cells and invasion into host cells are strictly coordinated processes, which can serve as targets to prevent infection. • Reaction and signalling of host cell depend on the cell type. • Campylobacter virulence factors can be used as targets for development of antivirulence drug compounds.
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Affiliation(s)
- Leon Kemper
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, Corrensstraße 48, 48149, Münster, Germany
| | - Andreas Hensel
- Institute of Pharmaceutical Biology and Phytochemistry, University of Münster, Corrensstraße 48, 48149, Münster, Germany.
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5
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Niedzwiecka A, Pham Q, Ling CC. Regiospecific O → N Acyl Migration as a Methodology to Access l-Altropyranosides with an N2, N4-Differentiation. Org Lett 2022; 24:8667-8671. [DOI: 10.1021/acs.orglett.2c03508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Anna Niedzwiecka
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Quyen Pham
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
| | - Chang-Chun Ling
- Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada
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6
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Differential Proteomics of Helicobacter pylori Isolates from Gastritis, Ulcer, and Cancer Patients: First Study from Northwest Pakistan. MEDICINA (KAUNAS, LITHUANIA) 2022; 58:medicina58091168. [PMID: 36143845 PMCID: PMC9500814 DOI: 10.3390/medicina58091168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 08/14/2022] [Accepted: 08/23/2022] [Indexed: 11/29/2022]
Abstract
Background and Objective: Helicobacter pylori is a human-stomach-dwelling organism that causes many gastric illnesses, including gastritis, ulcer, and gastric cancer. The purpose of the study was to perform differential proteomic analysis on H. pylori isolates from gastritis, ulcer, and gastric cancer patients. Materials and Methods: H. pylori was isolated from antrum and fundus biopsies obtained from patients who visited the Department of Gastroenterology. Using nano-LC-QTOF MS/MS analysis, differentially regulated proteins were identified through proteome profiling of pooled samples of H. pylori isolated from gastritis, ulcer, and gastric cancer patients. Antigenic scores and cellular localization of proteins were determined using additional prediction tools. Results: A total of 14 significantly regulated proteins were identified in H. pylori isolated from patients with either gastritis, ulcer, or gastric cancer. Comparative analysis of groups revealed that in the case of cancer vs. gastritis, six proteins were overexpressed, out of which two proteins, including hydrogenase maturation factor (hypA) and nucleoside diphosphate kinase (ndk) involved in bacterial colonization, were only upregulated in isolates from cancer patients. Similarly, in cancer vs. ulcer, a total of nine proteins were expressed. Sec-independent protein translocase protein (tatB), involved in protein translocation, and pseudaminic acid synthase I (pseI), involved in the synthesis of functional flagella, were upregulated in cancer, while hypA and ndk were downregulated. In ulcer vs. gastritis, eight proteins were expressed. In this group, tatB was overexpressed. A reduction in thioredoxin peroxidase (bacterioferritin co-migratory protein (bcp)) was observed in ulcer vs. gastritis and cancer vs. ulcer. Conclusion: Our study suggested three discrete protein signatures, hypA, tatB, and bcp, with differential expression in gastritis, ulcer, and cancer. Protein expression profiles of H. pylori isolated from patients with these gastric diseases will help to understand the virulence and pathogenesis of H. pylori.
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7
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Flagellotropic Bacteriophages: Opportunities and Challenges for Antimicrobial Applications. Int J Mol Sci 2022; 23:ijms23137084. [PMID: 35806089 PMCID: PMC9266447 DOI: 10.3390/ijms23137084] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/18/2022] [Accepted: 06/21/2022] [Indexed: 12/22/2022] Open
Abstract
Bacteriophages (phages) are the most abundant biological entities in the biosphere. As viruses that solely infect bacteria, phages have myriad healthcare and agricultural applications including phage therapy and antibacterial treatments in the foodservice industry. Phage therapy has been explored since the turn of the twentieth century but was no longer prioritized following the invention of antibiotics. As we approach a post-antibiotic society, phage therapy research has experienced a significant resurgence for the use of phages against antibiotic-resistant bacteria, a growing concern in modern medicine. Phages are extraordinarily diverse, as are their host receptor targets. Flagellotropic (flagellum-dependent) phages begin their infection cycle by attaching to the flagellum of their motile host, although the later stages of the infection process of most of these phages remain elusive. Flagella are helical appendages required for swimming and swarming motility and are also of great importance for virulence in many pathogenic bacteria of clinical relevance. Not only is bacterial motility itself frequently important for virulence, as it allows pathogenic bacteria to move toward their host and find nutrients more effectively, but flagella can also serve additional functions including mediating bacterial adhesion to surfaces. Flagella are also a potent antigen recognized by the human immune system. Phages utilizing the flagellum for infections are of particular interest due to the unique evolutionary tradeoff they force upon their hosts: by downregulating or abolishing motility to escape infection by a flagellotropic phage, a pathogenic bacterium would also likely attenuate its virulence. This factor may lead to flagellotropic phages becoming especially potent antibacterial agents. This review outlines past, present, and future research of flagellotropic phages, including their molecular mechanisms of infection and potential future applications.
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8
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Suban S, Sendersky E, Golden SS, Schwarz R. Impairment of a cyanobacterial glycosyltransferase that modifies a pilin results in biofilm development. ENVIRONMENTAL MICROBIOLOGY REPORTS 2022; 14:218-229. [PMID: 35172394 PMCID: PMC9306852 DOI: 10.1111/1758-2229.13050] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 02/03/2022] [Indexed: 05/03/2023]
Abstract
A biofilm inhibiting mechanism operates in the cyanobacterium Synechococcus elongatus. Here, we demonstrate that the glycosyltransferase homologue, Ogt, participates in the inhibitory process - inactivation of ogt results in robust biofilm formation. Furthermore, a mutational approach shows requirement of the glycosyltransferase activity for biofilm inhibition. This enzyme is necessary for glycosylation of the pilus subunit and for adequate pilus formation. In contrast to wild-type culture in which most cells exhibit several pili, only 25% of the mutant cells are piliated, half of which possess a single pilus. In spite of this poor piliation, natural DNA competence was similar to that of wild-type; therefore, we propose that the unglycosylated pili facilitate DNA transformation. Additionally, conditioned medium from wild-type culture, which contains a biofilm inhibiting substance(s), only partially blocks biofilm development by the ogt-mutant. Thus, we suggest that inactivation of ogt affects multiple processes including production or secretion of the inhibitor as well as the ability to sense or respond to it.
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Affiliation(s)
- Shiran Suban
- The Mina and Everard Goodman Faculty of Life SciencesBar‐Ilan UniversityRamat‐Gan5290002Israel
| | - Eleonora Sendersky
- The Mina and Everard Goodman Faculty of Life SciencesBar‐Ilan UniversityRamat‐Gan5290002Israel
| | - Susan S. Golden
- Division of Biological SciencesUniversity of California, San DiegoLa JollaCA92093USA
- Center for Circadian BiologyUniversity of California, San DiegoLa JollaCA92093USA
| | - Rakefet Schwarz
- The Mina and Everard Goodman Faculty of Life SciencesBar‐Ilan UniversityRamat‐Gan5290002Israel
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9
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Banahene N, Kavunja HW, Swarts BM. Chemical Reporters for Bacterial Glycans: Development and Applications. Chem Rev 2022; 122:3336-3413. [PMID: 34905344 PMCID: PMC8958928 DOI: 10.1021/acs.chemrev.1c00729] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bacteria possess an extraordinary repertoire of cell envelope glycans that have critical physiological functions. Pathogenic bacteria have glycans that are essential for growth and virulence but are absent from humans, making them high-priority targets for antibiotic, vaccine, and diagnostic development. The advent of metabolic labeling with bioorthogonal chemical reporters and small-molecule fluorescent reporters has enabled the investigation and targeting of specific bacterial glycans in their native environments. These tools have opened the door to imaging glycan dynamics, assaying and inhibiting glycan biosynthesis, profiling glycoproteins and glycan-binding proteins, and targeting pathogens with diagnostic and therapeutic payload. These capabilities have been wielded in diverse commensal and pathogenic Gram-positive, Gram-negative, and mycobacterial species─including within live host organisms. Here, we review the development and applications of chemical reporters for bacterial glycans, including peptidoglycan, lipopolysaccharide, glycoproteins, teichoic acids, and capsular polysaccharides, as well as mycobacterial glycans, including trehalose glycolipids and arabinan-containing glycoconjugates. We cover in detail how bacteria-targeting chemical reporters are designed, synthesized, and evaluated, how they operate from a mechanistic standpoint, and how this information informs their judicious and innovative application. We also provide a perspective on the current state and future directions of the field, underscoring the need for interdisciplinary teams to create novel tools and extend existing tools to support fundamental and translational research on bacterial glycans.
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10
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Surface Glucan Structures in Aeromonas spp. Mar Drugs 2021; 19:md19110649. [PMID: 34822520 PMCID: PMC8625153 DOI: 10.3390/md19110649] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 01/24/2023] Open
Abstract
Aeromonas spp. are generally found in aquatic environments, although they have also been isolated from both fresh and processed food. These Gram-negative, rod-shaped bacteria are mostly infective to poikilothermic animals, although they are also considered opportunistic pathogens of both aquatic and terrestrial homeotherms, and some species have been associated with gastrointestinal and extraintestinal septicemic infections in humans. Among the different pathogenic factors associated with virulence, several cell-surface glucans have been shown to contribute to colonization and survival of Aeromonas pathogenic strains, in different hosts. Lipopolysaccharide (LPS), capsule and α-glucan structures, for instance, have been shown to play important roles in bacterial–host interactions related to pathogenesis, such as adherence, biofilm formation, or immune evasion. In addition, glycosylation of both polar and lateral flagella has been shown to be mandatory for flagella production and motility in different Aeromonas strains, and has also been associated with increased bacterial adhesion, biofilm formation, and induction of the host proinflammatory response. The main aspects of these structures are covered in this review.
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11
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Yakovlieva L, Fülleborn JA, Walvoort MTC. Opportunities and Challenges of Bacterial Glycosylation for the Development of Novel Antibacterial Strategies. Front Microbiol 2021; 12:745702. [PMID: 34630370 PMCID: PMC8498110 DOI: 10.3389/fmicb.2021.745702] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 08/27/2021] [Indexed: 12/29/2022] Open
Abstract
Glycosylation is a ubiquitous process that is universally conserved in nature. The various products of glycosylation, such as polysaccharides, glycoproteins, and glycolipids, perform a myriad of intra- and extracellular functions. The multitude of roles performed by these molecules is reflected in the significant diversity of glycan structures and linkages found in eukaryotes and prokaryotes. Importantly, glycosylation is highly relevant for the virulence of many bacterial pathogens. Various surface-associated glycoconjugates have been identified in bacteria that promote infectious behavior and survival in the host through motility, adhesion, molecular mimicry, and immune system manipulation. Interestingly, bacterial glycosylation systems that produce these virulence factors frequently feature rare monosaccharides and unusual glycosylation mechanisms. Owing to their marked difference from human glycosylation, bacterial glycosylation systems constitute promising antibacterial targets. With the rise of antibiotic resistance and depletion of the antibiotic pipeline, novel drug targets are urgently needed. Bacteria-specific glycosylation systems are especially promising for antivirulence therapies that do not eliminate a bacterial population, but rather alleviate its pathogenesis. In this review, we describe a selection of unique glycosylation systems in bacterial pathogens and their role in bacterial homeostasis and infection, with a focus on virulence factors. In addition, recent advances to inhibit the enzymes involved in these glycosylation systems and target the bacterial glycan structures directly will be highlighted. Together, this review provides an overview of the current status and promise for the future of using bacterial glycosylation to develop novel antibacterial strategies.
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Affiliation(s)
- Liubov Yakovlieva
- Faculty of Science and Engineering, Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
| | - Julius A Fülleborn
- Faculty of Science and Engineering, Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
| | - Marthe T C Walvoort
- Faculty of Science and Engineering, Stratingh Institute for Chemistry, University of Groningen, Groningen, Netherlands
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12
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Reduced Infection Efficiency of Phage NCTC 12673 on Non-Motile Campylobacter jejuni Strains Is Related to Oxidative Stress. Viruses 2021; 13:v13101955. [PMID: 34696385 PMCID: PMC8540345 DOI: 10.3390/v13101955] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/08/2021] [Accepted: 09/20/2021] [Indexed: 01/26/2023] Open
Abstract
Campylobacter jejuni is a Gram-negative foodborne pathogen that causes diarrheal disease and is associated with severe post-infectious sequelae. Bacteriophages (phages) are a possible means of reducing Campylobacter colonization in poultry to prevent downstream human infections. However, the factors influencing phage-host interactions must be better understood before this strategy can be predictably employed. Most studies have focused on Campylobacter phage binding to the host surface, with all phages classified as either capsule- or flagella-specific. Here we describe the characterization of a C. jejuni phage that requires functional flagellar glycosylation and motor genes for infection, without needing the flagella for adsorption to the cell surface. Through phage infectivity studies of targeted C. jejuni mutants, transcriptomic analysis of phage-resistant mutants, and genotypic and phenotypic analysis of a spontaneous phage variant capable of simultaneously overcoming flagellar gene dependence and sensitivity to oxidative stress, we have uncovered a link between oxidative stress, flagellar motility, and phage infectivity. Taken together, our results underscore the importance of understanding phage-host interactions beyond the cell surface and point to host oxidative stress state as an important and underappreciated consideration for future phage-host interaction studies.
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13
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Wei R, Yang X, Liu H, Wei T, Chen S, Li X. Synthetic Pseudaminic-Acid-Based Antibacterial Vaccine Confers Effective Protection against Acinetobacter baumannii Infection. ACS CENTRAL SCIENCE 2021; 7:1535-1542. [PMID: 34584955 PMCID: PMC8461771 DOI: 10.1021/acscentsci.1c00656] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Indexed: 05/05/2023]
Abstract
Acinetobacter baumannii exhibits resistance to most first-line antibiotics; thus, development of new antibacterial agents is urgently required. Pseudaminic acid exists as the surface glycan of A. baumannii. In this study, we chemically synthesized pseudaminic acid, conjugated it to carrier protein CRM197 using the OPA (ortho-phthalaldehyde) chemistry, and obtained three Pse-CRM197 conjugates with different Pse loadings. These Pse-CRM197 conjugates were found to stimulate high immune responses in mice, which protected the vaccinated mice from infections caused by Pse-producing A. baumannii. Our data indicate that chemically synthesized Pse-CRM197 conjugates can be developed into vaccines against Pse-bearing pathogens, thus offering a feasible alternative for the control of clinical infections caused by multidrug-resistant (MDR) A. baumannii, for which current treatment options are extremely limited.
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Affiliation(s)
- Ruohan Wei
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, 999077 Pokfulam, Hong Kong SAR,
P. R. China
| | - Xuemei Yang
- Department
of Infectious Diseases and Public Health, Jockey Club College of Veterinary
Medicine and Life Sciences, City University
of Hong Kong, 999077 Kowloon, Hong Kong SAR,
P. R. China
| | - Han Liu
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, 999077 Pokfulam, Hong Kong SAR,
P. R. China
| | - Tongyao Wei
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, 999077 Pokfulam, Hong Kong SAR,
P. R. China
| | - Sheng Chen
- Department
of Infectious Diseases and Public Health, Jockey Club College of Veterinary
Medicine and Life Sciences, City University
of Hong Kong, 999077 Kowloon, Hong Kong SAR,
P. R. China
| | - Xuechen Li
- Department
of Chemistry, the State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Pokfulam Road, 999077 Pokfulam, Hong Kong SAR,
P. R. China
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14
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CdgL is a degenerate nucleotide cyclase domain protein affecting flagellin synthesis and motility in Bacillus thuringiensis. Res Microbiol 2021; 172:103850. [PMID: 34082027 DOI: 10.1016/j.resmic.2021.103850] [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: 10/02/2020] [Revised: 02/28/2021] [Accepted: 05/27/2021] [Indexed: 11/23/2022]
Abstract
In Bacillus subtilis, motility genes are expressed in a hierarchical pattern - governed by the σD transcription factor and other proteins such as the EpsE molecular clutch and SlrA/SlrR regulator proteins. In contrast, motile species in the Bacillus cereus group seem to express their motility genes in a non-hierarchical pattern, and less is known about their regulation, also given that no orthologs to σD, EpsE, SlrA or SlrR are found in B. cereus group genomes. Here we show that deletion of cdgL (BTB_RS26690/BTB_c54300) in Bacillus thuringiensis 407 (cry-) resulted in a six-to ten-fold downregulation of the entire motility locus, and loss of flagellar structures and swimming motility. cdgL is unique to the B. cereus group and is found in all phylogenetic clusters in the population except for group I, which comprises isolates of non-motile Bacillus pseudomycoides. Analysis of RNA-Seq data revealed cdgL to be expressed in a three-gene operon with a NupC like nucleoside transporter, and a putative glycosyl transferase for which transposon-based gene inactivation was previously shown to produce a similar phenotype to cdgL deletion. Interestingly, all three proteins were predicted to be membrane-bound and may provide a concerted function in the regulation of B. cereus group motility.
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Yang K, Kao C, Su MS, Wang S, Chen Y, Hu S, Chen J, Teng C, Tsai P, Wu J. Glycosyltransferase Jhp0106 (PseE) contributes to flagellin maturation in Helicobacter pylori. Helicobacter 2021; 26:e12787. [PMID: 33586844 PMCID: PMC7988653 DOI: 10.1111/hel.12787] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 01/26/2021] [Accepted: 01/26/2021] [Indexed: 01/25/2023]
Abstract
BACKGROUND Flagella-mediated motility is both a crucial virulence determinant of Helicobacter pylori and a factor associated with gastrointestinal diseases. Flagellar formation requires flagellins to be glycosylated with pseudaminic acid (Pse), a process that has been extensively studied. However, the transfer of Pse to flagellins remains poorly understood. Therefore, the aim of this study is to characterize a putative glycosyltransferase jhp0106 in flagellar formation. MATERIALS AND METHODS Western blotting and chemical deglycosylation were performed to examine FlaA glycosylation. Protein structural analyses were executed to identify the active site residues of Jhp0106, while the Jhp0106-FlaA interaction was examined using a bacterial two-hybrid assay. Lastly, site-directed mutants with mutated active site residues in the jhp0106 gene were generated and investigated using a motility assay, Western blotting, cDNA-qPCR analysis, and electron microscopic examination. RESULTS Loss of flagellar formation in the Δjhp0106 mutant was confirmed to be associated with non-glycosylated FlaA. Furthermore, three active site residues of Jhp0106 (S350, F376, and E415) were identified within a potential substrate-binding region. The interaction between FlaA and Jhp0106, Jhp0106::S350A, Jhp0106::F376A, or Jhp0106::E415A was determined to be significant. As well, the substitution of S350A, F376A, or E415A in the site-directed Δjhp0106 mutants resulted in impaired motility, deficient FlaA glycosylation, and lacking flagella. However, these phenotypic changes were regardless of flaA expression, implying an indefinite proteolytic degradation of FlaA occurred. CONCLUSIONS This study demonstrated that Jhp0106 (PseE) binds to FlaA mediating FlaA glycosylation and flagellar formation. Our discovery of PseE has revealed a new glycosyltransferase family responsible for flagellin glycosylation in pathogens.
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Affiliation(s)
- Kai‐Yuan Yang
- Institute of Microbiology and ImmunologySchool of Life ScienceNational Yang‐Ming UniversityTaipeiTaiwan
| | - Cheng‐Yen Kao
- Institute of Microbiology and ImmunologySchool of Life ScienceNational Yang‐Ming UniversityTaipeiTaiwan,Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
| | - Marcia Shu‐Wei Su
- Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
| | - Shuying Wang
- Department of Microbiology and ImmunologyCollege of MedicineNational Cheng‐Kung UniversityTainanTaiwan
| | - Yueh‐Lin Chen
- Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
| | - Shiau‐Ting Hu
- Institute of Microbiology and ImmunologySchool of Life ScienceNational Yang‐Ming UniversityTaipeiTaiwan
| | - Jenn‐Wei Chen
- Department of Microbiology and ImmunologyCollege of MedicineNational Cheng‐Kung UniversityTainanTaiwan
| | - Ching‐Hao Teng
- Institute of Molecular MedicineCollege of MedicineNational Cheng Kung UniversityTainanTaiwan
| | - Pei‐Jane Tsai
- Department of Medical Laboratory Science and BiotechnologyCollege of MedicineNational Cheng Kung UniversityTainanTaiwan
| | - Jiunn‐Jong Wu
- Department of Biotechnology and Laboratory Science in MedicineSchool of Biomedical Science and EngineeringNational Yang‐Ming UniversityTaipeiTaiwan
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Proteomic Adaptation of Clostridioides difficile to Treatment with the Antimicrobial Peptide Nisin. Cells 2021; 10:cells10020372. [PMID: 33670309 PMCID: PMC7918085 DOI: 10.3390/cells10020372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 02/04/2021] [Accepted: 02/08/2021] [Indexed: 01/05/2023] Open
Abstract
Clostridioides difficile is the leading cause of antibiotic-associated diarrhea but can also result in more serious, life-threatening conditions. The incidence of C. difficile infections in hospitals is increasing, both in frequency and severity, and antibiotic-resistant C. difficile strains are advancing. Against this background antimicrobial peptides (AMPs) are an interesting alternative to classic antibiotics. Information on the effects of AMPs on C. difficile will not only enhance the knowledge for possible biomedical application but may also provide insights into mechanisms of C. difficile to adapt or counteract AMPs. This study applies state-of-the-art mass spectrometry methods to quantitatively investigate the proteomic response of C. difficile 630∆erm to sublethal concentrations of the AMP nisin allowing to follow the cellular stress adaptation in a time-resolved manner. The results do not only point at a heavy reorganization of the cellular envelope but also resulted in pronounced changes in central cellular processes such as carbohydrate metabolism. Further, the number of flagella per cell was increased during the adaptation process. The potential involvement of flagella in nisin adaptation was supported by a more resistant phenotype exhibited by a non-motile but hyper-flagellated mutant.
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Flagellar Structures from the Bacterium Caulobacter crescentus and Implications for Phage ϕ CbK Predation of Multiflagellin Bacteria. J Bacteriol 2021; 203:JB.00399-20. [PMID: 33288623 DOI: 10.1128/jb.00399-20] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/02/2020] [Indexed: 02/06/2023] Open
Abstract
Caulobacter crescentus is a Gram-negative alphaproteobacterium that commonly lives in oligotrophic fresh- and saltwater environments. C. crescentus is a host to many bacteriophages, including ϕCbK and ϕCbK-like bacteriophages, which require interaction with the bacterial flagellum and pilus complexes during adsorption. It is commonly thought that the six paralogs of the flagellin gene present in C. crescentus are important for bacteriophage evasion. Here, we show that deletion of specific flagellins in C. crescentus can indeed attenuate ϕCbK adsorption efficiency, although no single deletion completely ablates ϕCbK adsorption. Thus, the bacteriophage ϕCbK likely recognizes a common motif among the six known flagellins in C. crescentus with various degrees of efficiency. Interestingly, we observe that most deletion strains still generate flagellar filaments, with the exception of a strain that contains only the most divergent flagellin, FljJ, or a strain that contains only FljN and FljO. To visualize the surface residues that are likely recognized by ϕCbK, we determined two high-resolution structures of the FljK filament, with and without an amino acid substitution that induces straightening of the filament. We observe posttranslational modifications on conserved surface threonine residues of FljK that are likely O-linked glycans. The possibility of interplay between these modifications and ϕCbK adsorption is discussed. We also determined the structure of a filament composed of a heterogeneous mixture of FljK and FljL, the final resolution of which was limited to approximately 4.6 Å. Altogether, this work builds a platform for future investigations of how phage ϕCbK infects C. crescentus at the molecular level.IMPORTANCE Bacterial flagellar filaments serve as an initial attachment point for many bacteriophages to bacteria. Some bacteria harbor numerous flagellin genes and are therefore able to generate flagellar filaments with complex compositions, which is thought to be important for evasion from bacteriophages. This study characterizes the importance of the six flagellin genes in C. crescentus for infection by bacteriophage ϕCbK. We find that filaments containing the FljK flagellin are the preferred substrate for bacteriophage ϕCbK. We also present a high-resolution structure of a flagellar filament containing only the FljK flagellin, which provides a platform for future studies on determining how bacteriophage ϕCbK attaches to flagellar filaments at the molecular level.
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Eguchi N, Suzuki S, Yokota K, Igimi S, Kajikawa A. Ligilactobacillus agilis BKN88 possesses thermo-/acid-stable heteropolymeric flagellar filaments. MICROBIOLOGY-SGM 2021; 167. [PMID: 33502302 DOI: 10.1099/mic.0.001020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Many flagellated bacteria possess multiple flagellins, but the roles and the compositions of each flagellin are diverse and poorly understood. In Ligilactobacillus agilis BKN88, there are two active flagellin gene paralogues but their function and composition in its flagellar filaments have not been described. The aim of this study is to find the function and composition of the flagellins by employing mutant strains each of which expresses a single flagellin or a modified flagellin. Two single flagellin-expressing strains were both flagellated while the number of flagella per cell in the single flagellin-expressing derivatives was lower than that in the wild type. Nonetheless, these derivative strains were apparently equally motile as the wild type. This indicates that either flagellin is sufficient for cell motility. The immunological activity via Toll-like receptor 5 of the single flagellin-expressing strains or purified single flagellins was readily detectable but mostly variably weaker than that of the wild type. The flagellar filaments of wild type L. agilis BKN88 were more acid-/thermo-stable than those of single flagellin-expressing derivatives. Using a combination of immunoprecipitation and flagellin-specific staining, wild type BKN88 appeared to possess heteropolymeric flagellar filaments consisting of both flagellins and each flagellin appeared to be equally distributed throughout the filaments. The results of this study suggest that the two flagellins together form a more robust filament than either alone and are thus functionally complementary.
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Affiliation(s)
- Naoto Eguchi
- Department of Agricultural Chemistry, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan
| | - Shunya Suzuki
- Department of Agricultural Chemistry, Graduate School of Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan
| | - Kenji Yokota
- Department of Agricultural Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan
| | - Shizunobu Igimi
- Department of Agricultural Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan
| | - Akinobu Kajikawa
- Department of Agricultural Chemistry, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya, Tokyo 156-8502, Japan
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Niedzwiecka A, Sequeira C, Zhang P, Ling CC. An efficient and scalable synthesis of 2,4-di- N-acetyl- l-altrose ( l-2,4-Alt-diNAc). RSC Adv 2021; 11:11583-11594. [PMID: 35423663 PMCID: PMC8695972 DOI: 10.1039/d1ra01070k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/12/2021] [Indexed: 12/17/2022] Open
Abstract
An efficient and scalable synthesis of pseudaminic acid precursor l-2,4-Alt-diNAc was developed from l-fucose. The desired l-altro configuration and N-acetamido substitutions ensued from a sequence of highly regio- and stereoselective transformations.
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Affiliation(s)
| | | | - Ping Zhang
- Department of Chemistry
- University of Calgary
- Calgary
- Canada
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20
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Ardissone S, Kint N, Viollier PH. Specificity in glycosylation of multiple flagellins by the modular and cell cycle regulated glycosyltransferase FlmG. eLife 2020; 9:e60488. [PMID: 33108275 PMCID: PMC7591256 DOI: 10.7554/elife.60488] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 09/24/2020] [Indexed: 12/12/2022] Open
Abstract
How specificity is programmed into post-translational modification of proteins by glycosylation is poorly understood, especially for O-linked glycosylation systems. Here we reconstitute and dissect the substrate specificity underpinning the cytoplasmic O-glycosylation pathway that modifies all six flagellins, five structural and one regulatory paralog, in Caulobacter crescentus, a monopolarly flagellated alpha-proteobacterium. We characterize the biosynthetic pathway for the sialic acid-like sugar pseudaminic acid and show its requirement for flagellation, flagellin modification and efficient export. The cognate NeuB enzyme that condenses phosphoenolpyruvate with a hexose into pseudaminic acid is functionally interchangeable with other pseudaminic acid synthases. The previously unknown and cell cycle-regulated FlmG protein, a defining member of a new class of cytoplasmic O-glycosyltransferases, is required and sufficient for flagellin modification. The substrate specificity of FlmG is conferred by its N-terminal flagellin-binding domain. FlmG accumulates before the FlaF secretion chaperone, potentially timing flagellin modification, export, and assembly during the cell division cycle.
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Affiliation(s)
- Silvia Ardissone
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
| | - Nicolas Kint
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine, Faculty of Medicine / CMU, University of GenevaGenèveSwitzerland
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21
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De Maayer P, Pillay T, Coutinho TA. Flagella by numbers: comparative genomic analysis of the supernumerary flagellar systems among the Enterobacterales. BMC Genomics 2020; 21:670. [PMID: 32993503 PMCID: PMC7526173 DOI: 10.1186/s12864-020-07085-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 09/21/2020] [Indexed: 01/17/2023] Open
Abstract
Background Flagellar motility is an efficient means of movement that allows bacteria to successfully colonize and compete with other microorganisms within their respective environments. The production and functioning of flagella is highly energy intensive and therefore flagellar motility is a tightly regulated process. Despite this, some bacteria have been observed to possess multiple flagellar systems which allow distinct forms of motility. Results Comparative genomic analyses showed that, in addition to the previously identified primary peritrichous (flag-1) and secondary, lateral (flag-2) flagellar loci, three novel types of flagellar loci, varying in both gene content and gene order, are encoded on the genomes of members of the order Enterobacterales. The flag-3 and flag-4 loci encode predicted peritrichous flagellar systems while the flag-5 locus encodes a polar flagellum. In total, 798/4028 (~ 20%) of the studied taxa incorporate dual flagellar systems, while nineteen taxa incorporate three distinct flagellar loci. Phylogenetic analyses indicate the complex evolutionary histories of the flagellar systems among the Enterobacterales. Conclusions Supernumerary flagellar loci are relatively common features across a broad taxonomic spectrum in the order Enterobacterales. Here, we report the occurrence of five (flag-1 to flag-5) flagellar loci on the genomes of enterobacterial taxa, as well as the occurrence of three flagellar systems in select members of the Enterobacterales. Considering the energetic burden of maintaining and operating multiple flagellar systems, they are likely to play a role in the ecological success of members of this family and we postulate on their potential biological functions.
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Affiliation(s)
- Pieter De Maayer
- School of Molecular & Cell Biology, University of the Witwatersrand, Wits, 2050, South Africa.
| | - Talia Pillay
- School of Molecular & Cell Biology, University of the Witwatersrand, Wits, 2050, South Africa
| | - Teresa A Coutinho
- Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, 0002, South Africa
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22
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Khairnar A, Sunsunwal S, Babu P, Ramya TNC. Novel serine/threonine-O-glycosylation with N-acetylneuraminic acid and 3-deoxy-D-manno-octulosonic acid by bacterial flagellin glycosyltransferases. Glycobiology 2020; 31:288-306. [PMID: 32886756 DOI: 10.1093/glycob/cwaa084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/05/2020] [Accepted: 08/24/2020] [Indexed: 12/15/2022] Open
Abstract
Some bacterial flagellins are O-glycosylated on surface-exposed serine/threonine residues with nonulosonic acids such as pseudaminic acid, legionaminic acid and their derivatives by flagellin nonulosonic acid glycosyltransferases, also called motility-associated factors (Maf). We report here two new glycosidic linkages previously unknown in any organism, serine/threonine-O-linked N-acetylneuraminic acid (Ser/Thr-O-Neu5Ac) and serine/threonine-O-linked 3-deoxy-D-manno-octulosonic acid or keto-deoxyoctulosonate (Ser/Thr-O-KDO), both catalyzed by Geobacillus kaustophilus Maf and Clostridium botulinum Maf. We identified these novel glycosidic linkages in recombinant G. kaustophilus and C. botulinum flagellins that were coexpressed with their cognate recombinant Maf protein in Escherichia coli strains producing the appropriate nucleotide sugar glycosyl donor. Our finding that both G. kaustophilus Maf (putative flagellin sialyltransferase) and C. botulinum Maf (putative flagellin legionaminic acid transferase) catalyzed Neu5Ac and KDO transfer on to flagellin indicates that Maf glycosyltransferases display donor substrate promiscuity. Maf glycosyltransferases have the potential to radically expand the scope of neoglycopeptide synthesis and posttranslational protein engineering.
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Affiliation(s)
- Aasawari Khairnar
- Department of Protein Science and Engineering, CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Sonali Sunsunwal
- Department of Protein Science and Engineering, CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
| | - Ponnusamy Babu
- Glycomics and Glycoproteomics & Biologics Characterization Facility, Centre for Cellular and Molecular Platforms, National Centre for Biological Sciences-TIFR, Bengaluru, UAS-GKVK Campus, Bellary Road, 560065, India
| | - T N C Ramya
- Department of Protein Science and Engineering, CSIR-Institute of Microbial Technology, Sector 39-A, Chandigarh 160036, India
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Methylation of Salmonella Typhimurium flagella promotes bacterial adhesion and host cell invasion. Nat Commun 2020; 11:2013. [PMID: 32332720 PMCID: PMC7181671 DOI: 10.1038/s41467-020-15738-3] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 03/13/2020] [Indexed: 11/09/2022] Open
Abstract
The long external filament of bacterial flagella is composed of several thousand copies of a single protein, flagellin. Here, we explore the role played by lysine methylation of flagellin in Salmonella, which requires the methylase FliB. We show that both flagellins of Salmonella enterica serovar Typhimurium, FliC and FljB, are methylated at surface-exposed lysine residues by FliB. A Salmonella Typhimurium mutant deficient in flagellin methylation is outcompeted for gut colonization in a gastroenteritis mouse model, and methylation of flagellin promotes bacterial invasion of epithelial cells in vitro. Lysine methylation increases the surface hydrophobicity of flagellin, and enhances flagella-dependent adhesion of Salmonella to phosphatidylcholine vesicles and epithelial cells. Therefore, posttranslational methylation of flagellin facilitates adhesion of Salmonella Typhimurium to hydrophobic host cell surfaces, and contributes to efficient gut colonization and host infection. Flagellin proteins of Salmonella flagella are methylated. Here, the authors show that flagellin methylation facilitates adhesion of Salmonella to hydrophobic host-cell surfaces, and contributes to efficient gut colonization and host infection.
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24
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Sacher JC, Shajahan A, Butcher J, Patry RT, Flint A, Hendrixson DR, Stintzi A, Azadi P, Szymanski CM. Binding of Phage-Encoded FlaGrab to Motile Campylobacter jejuni Flagella Inhibits Growth, Downregulates Energy Metabolism, and Requires Specific Flagellar Glycans. Front Microbiol 2020; 11:397. [PMID: 32265863 PMCID: PMC7099621 DOI: 10.3389/fmicb.2020.00397] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 02/26/2020] [Indexed: 12/20/2022] Open
Abstract
Many bacterial pathogens display glycosylated surface structures that contribute to virulence, and targeting these structures is a viable strategy for pathogen control. The foodborne pathogen Campylobacter jejuni expresses a vast diversity of flagellar glycans, and flagellar glycosylation is essential for its virulence. Little is known about why C. jejuni encodes such a diverse set of flagellar glycans, but it has been hypothesized that evolutionary pressure from bacteriophages (phages) may have contributed to this diversity. However, interactions between Campylobacter phages and host flagellar glycans have not been characterized in detail. Previously, we observed that Gp047 (now renamed FlaGrab), a conserved Campylobacter phage protein, binds to C. jejuni flagella displaying the nine-carbon monosaccharide 7-acetamidino-pseudaminic acid, and that this binding partially inhibits cell growth. However, the mechanism of this growth inhibition, as well as how C. jejuni might resist this activity, are not well-understood. Here we use RNA-Seq to show that FlaGrab exposure leads C. jejuni 11168 cells to downregulate expression of energy metabolism genes, and that FlaGrab-induced growth inhibition is dependent on motile flagella. Our results are consistent with a model whereby FlaGrab binding transmits a signal through flagella that leads to retarded cell growth. To evaluate mechanisms of FlaGrab resistance in C. jejuni, we characterized the flagellar glycans and flagellar glycosylation loci of two C. jejuni strains naturally resistant to FlaGrab binding. Our results point toward flagellar glycan diversity as the mechanism of resistance to FlaGrab. Overall, we have further characterized the interaction between this phage-encoded flagellar glycan-binding protein and C. jejuni, both in terms of mechanism of action and mechanism of resistance. Our results suggest that C. jejuni encodes as-yet unidentified mechanisms for generating flagellar glycan diversity, and point to phage proteins as exciting lenses through which to study bacterial surface glycans.
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Affiliation(s)
- Jessica C Sacher
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Asif Shajahan
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - James Butcher
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Robert T Patry
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States.,Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Annika Flint
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - David R Hendrixson
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Alain Stintzi
- Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States.,Department of Microbiology, University of Georgia, Athens, GA, United States
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Type III Secretion Effectors with Arginine N-Glycosyltransferase Activity. Microorganisms 2020; 8:microorganisms8030357. [PMID: 32131463 PMCID: PMC7142665 DOI: 10.3390/microorganisms8030357] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 02/27/2020] [Accepted: 02/29/2020] [Indexed: 01/31/2023] Open
Abstract
Type III secretion systems are used by many Gram-negative bacterial pathogens to inject proteins, known as effectors, into the cytosol of host cells. These virulence factors interfere with a diverse array of host signal transduction pathways and cellular processes. Many effectors have catalytic activities to promote post-translational modifications of host proteins. This review focuses on a family of effectors with glycosyltransferase activity that catalyze addition of N-acetyl-d-glucosamine to specific arginine residues in target proteins, leading to reduced NF-κB pathway activation and impaired host cell death. This family includes NleB from Citrobacter rodentium, NleB1 and NleB2 from enteropathogenic and enterohemorrhagic Escherichia coli, and SseK1, SseK2, and SseK3 from Salmonella enterica. First, we place these effectors in the general framework of the glycosyltransferase superfamily and in the particular context of the role of glycosylation in bacterial pathogenesis. Then, we provide detailed information about currently known members of this family, their role in virulence, and their targets.
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26
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Chu J, Liu J, Hoover TR. Phylogenetic Distribution, Ultrastructure, and Function of Bacterial Flagellar Sheaths. Biomolecules 2020; 10:biom10030363. [PMID: 32120823 PMCID: PMC7175336 DOI: 10.3390/biom10030363] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 02/06/2023] Open
Abstract
A number of Gram-negative bacteria have a membrane surrounding their flagella, referred to as the flagellar sheath, which is continuous with the outer membrane. The flagellar sheath was initially described in Vibrio metschnikovii in the early 1950s as an extension of the outer cell wall layer that completely surrounded the flagellar filament. Subsequent studies identified other bacteria that possess flagellar sheaths, most of which are restricted to a few genera of the phylum Proteobacteria. Biochemical analysis of the flagellar sheaths from a few bacterial species revealed the presence of lipopolysaccharide, phospholipids, and outer membrane proteins in the sheath. Some proteins localize preferentially to the flagellar sheath, indicating mechanisms exist for protein partitioning to the sheath. Recent cryo-electron tomography studies have yielded high resolution images of the flagellar sheath and other structures closely associated with the sheath, which has generated insights and new hypotheses for how the flagellar sheath is synthesized. Various functions have been proposed for the flagellar sheath, including preventing disassociation of the flagellin subunits in the presence of gastric acid, avoiding activation of the host innate immune response by flagellin, activating the host immune response, adherence to host cells, and protecting the bacterium from bacteriophages.
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Affiliation(s)
- Joshua Chu
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA;
| | - Jun Liu
- Microbial Sciences Institute, Department of Microbial Pathogenesis, Yale University, West Haven, CT 06516, USA;
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Correspondence: ; Tel.: +1-706-542-2675
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Alzheimer M, Svensson SL, König F, Schweinlin M, Metzger M, Walles H, Sharma CM. A three-dimensional intestinal tissue model reveals factors and small regulatory RNAs important for colonization with Campylobacter jejuni. PLoS Pathog 2020; 16:e1008304. [PMID: 32069333 PMCID: PMC7048300 DOI: 10.1371/journal.ppat.1008304] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 02/28/2020] [Accepted: 01/02/2020] [Indexed: 02/06/2023] Open
Abstract
The Gram-negative Epsilonproteobacterium Campylobacter jejuni is currently the most prevalent bacterial foodborne pathogen. Like for many other human pathogens, infection studies with C. jejuni mainly employ artificial animal or cell culture models that can be limited in their ability to reflect the in-vivo environment within the human host. Here, we report the development and application of a human three-dimensional (3D) infection model based on tissue engineering to study host-pathogen interactions. Our intestinal 3D tissue model is built on a decellularized extracellular matrix scaffold, which is reseeded with human Caco-2 cells. Dynamic culture conditions enable the formation of a polarized mucosal epithelial barrier reminiscent of the 3D microarchitecture of the human small intestine. Infection with C. jejuni demonstrates that the 3D tissue model can reveal isolate-dependent colonization and barrier disruption phenotypes accompanied by perturbed localization of cell-cell junctions. Pathogenesis-related phenotypes of C. jejuni mutant strains in the 3D model deviated from those obtained with 2D-monolayers, but recapitulated phenotypes previously observed in animal models. Moreover, we demonstrate the involvement of a small regulatory RNA pair, CJnc180/190, during infections and observe different phenotypes of CJnc180/190 mutant strains in 2D vs. 3D infection models. Hereby, the CJnc190 sRNA exerts its pathogenic influence, at least in part, via repression of PtmG, which is involved in flagellin modification. Our results suggest that the Caco-2 cell-based 3D tissue model is a valuable and biologically relevant tool between in-vitro and in-vivo infection models to study virulence of C. jejuni and other gastrointestinal pathogens. Enteric pathogens have evolved numerous strategies to successfully colonize and persist in the human gastrointestinal tract. However, especially for the research of virulence mechanisms of human pathogens, often only limited infection models are available. Here, we have applied and further advanced a tissue-engineered human intestinal tissue model based on an extracellular matrix scaffold reseeded with human cells that can faithfully mimic pathogenesis-determining processes of the zoonotic pathogen Campylobacter jejuni. Our three-dimensional (3D) intestinal infection model allows for the assessment of epithelial barrier function during infection as well as for the quantification of bacterial adherence, internalization, and transmigration. Investigation of C. jejuni mutant strains in our 3D tissue model revealed isolate-specific infection phenotypes, in-vivo relevant infection outcomes, and uncovered the involvement of a small RNA pair during C. jejuni pathogenesis. Overall, our results demonstrate the power of tissue-engineered models for studying host-pathogen interactions, and our model will also be helpful to investigate other gastrointestinal pathogens.
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Affiliation(s)
- Mona Alzheimer
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Sarah L. Svensson
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Fabian König
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Matthias Schweinlin
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Marco Metzger
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, Würzburg, Germany
- Fraunhofer-Institute for Silicate Research, Translational Centre Regenerative Therapies, Würzburg, Germany
| | - Heike Walles
- Department of Tissue Engineering and Regenerative Medicine, University Hospital Würzburg, Würzburg, Germany
- Core Facility Tissue Engineering, Otto-von-Guericke University, Magdeburg, Germany
- * E-mail: (HW); (CMS)
| | - Cynthia M. Sharma
- Chair of Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
- * E-mail: (HW); (CMS)
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De Maayer P, Pillay T, Coutinho TA. Comparative genomic analysis of the secondary flagellar (flag-2) system in the order Enterobacterales. BMC Genomics 2020; 21:100. [PMID: 32000682 PMCID: PMC6993521 DOI: 10.1186/s12864-020-6529-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/22/2020] [Indexed: 01/24/2023] Open
Abstract
Background The order Enterobacterales encompasses a broad range of metabolically and ecologically versatile bacterial taxa, most of which are motile by means of peritrichous flagella. Flagellar biosynthesis has been linked to a primary flagella locus, flag-1, encompassing ~ 50 genes. A discrete locus, flag-2, encoding a distinct flagellar system, has been observed in a limited number of enterobacterial taxa, but its function remains largely uncharacterized. Results Comparative genomic analyses showed that orthologous flag-2 loci are present in 592/4028 taxa belonging to 5/8 and 31/76 families and genera, respectively, in the order Enterobacterales. Furthermore, the presence of only the outermost flag-2 genes in many taxa suggests that this locus was far more prevalent and has subsequently been lost through gene deletion events. The flag-2 loci range in size from ~ 3.4 to 81.1 kilobases and code for between five and 102 distinct proteins. The discrepancy in size and protein number can be attributed to the presence of cargo gene islands within the loci. Evolutionary analyses revealed a complex evolutionary history for the flag-2 loci, representing ancestral elements in some taxa, while showing evidence of recent horizontal acquisition in other enterobacteria. Conclusions The flag-2 flagellar system is a fairly common, but highly variable feature among members of the Enterobacterales. Given the energetic burden of flagellar biosynthesis and functioning, the prevalence of a second flagellar system suggests it plays important biological roles in the enterobacteria and we postulate on its potential role as locomotory organ or as secretion system.
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Affiliation(s)
- Pieter De Maayer
- School of Molecular & Cell Biology, University of the Witwatersrand, 2050 Wits, Johannesburg, South Africa.
| | - Talia Pillay
- School of Molecular & Cell Biology, University of the Witwatersrand, 2050 Wits, Johannesburg, South Africa
| | - Teresa A Coutinho
- Centre for Microbial Ecology and Genomics, University of Pretoria 0002, Pretoria, South Africa
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Irons J, Sacher JC, Szymanski CM, Downs DM. Cj1388 Is a RidA Homolog and Is Required for Flagella Biosynthesis and/or Function in Campylobacter jejuni. Front Microbiol 2019; 10:2058. [PMID: 31555246 PMCID: PMC6742949 DOI: 10.3389/fmicb.2019.02058] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 08/20/2019] [Indexed: 12/18/2022] Open
Abstract
Campylobacter jejuni is the leading bacterial cause of acute gastroenteritis worldwide and thus significant to public health. C. jejuni primarily lives in the gastrointestinal tracts of poultry and can contaminate meat during processing. Despite a small genome, the metabolic plasticity of C. jejuni allows proliferation in chicken ceca and mammalian host intestines, and survival in environments with a variety of temperatures, pH, osmotic conditions, and nutrient availabilities. The exact mechanism of C. jejuni infection is unknown, however, virulence requires motility. Our data suggest the C. jejuni RidA homolog, Cj1388, plays a role in flagellar biosynthesis, regulation, structure, and/or function and, as such is expected to influence virulence of the organism. Mutants lacking cj1388 have defects in motility, autoagglutination, and phage infectivity under the conditions tested. Comparison to the RidA paradigm from Salmonella enterica indicates the phenotypes of the C. jejuni cj1388 mutant are likely due to the inhibition of one or more pyridoxal 5'-phosphate-dependent enzymes by the reactive enamine 2-aminoacrylate.
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Affiliation(s)
- Jessica Irons
- Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Jessica C Sacher
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Christine M Szymanski
- Department of Microbiology, University of Georgia, Athens, GA, United States.,Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Diana M Downs
- Department of Microbiology, University of Georgia, Athens, GA, United States
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Abstract
Over the past decade the number and variety of protein post-translational modifications that have been detected and characterized in bacteria have rapidly increased. Most post-translational protein modifications occur in a relatively low number of bacterial proteins in comparison with eukaryotic proteins, and most of the modified proteins carry low, substoichiometric levels of modification; therefore, their structural and functional analysis is particularly challenging. The number of modifying enzymes differs greatly among bacterial species, and the extent of the modified proteome strongly depends on environmental conditions. Nevertheless, evidence is rapidly accumulating that protein post-translational modifications have vital roles in various cellular processes such as protein synthesis and turnover, nitrogen metabolism, the cell cycle, dormancy, sporulation, spore germination, persistence and virulence. Further research of protein post-translational modifications will fill current gaps in the understanding of bacterial physiology and open new avenues for treatment of infectious diseases.
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Koomey M. O-linked protein glycosylation in bacteria: snapshots and current perspectives. Curr Opin Struct Biol 2019; 56:198-203. [DOI: 10.1016/j.sbi.2019.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/22/2019] [Accepted: 03/13/2019] [Indexed: 12/27/2022]
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Tiwari V. Post-translational modification of ESKAPE pathogens as a potential target in drug discovery. Drug Discov Today 2018; 24:814-822. [PMID: 30572117 DOI: 10.1016/j.drudis.2018.12.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 11/23/2018] [Accepted: 12/12/2018] [Indexed: 12/19/2022]
Abstract
ESKAPE pathogens are gaining clinical importance owing to their high pervasiveness and increasing resistance to various antimicrobials. These bacteria have several post-translational modifications (PTMs) that destabilize or divert host cell pathways. Prevalent PTMs of ESKAPE pathogens include addition of chemical groups (acetylation, phosphorylation, methylation and hydroxylation) or complex molecules (AMPylation, ADP-ribosylation, glycosylation and isoprenylation), covalently linked small proteins [ubiquitylation, ubiquitin-like proteins (UBL) conjugation and small ubiquitin-like modifier (SUMO)] or modification of amino acid side-chains (eliminylation and deamidation). Therefore, the understanding of different bacterial PTMs and host proteins manipulated by these PTMs provides better insight into host-pathogen interaction and will also help to develop new antibacterial agents against ESKAPE pathogens.
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Affiliation(s)
- Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Bandarsindri, Ajmer 305817, India.
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Smith JA, Bar-Peled M. Identification of an apiosyltransferase in the plant pathogen Xanthomonas pisi. PLoS One 2018; 13:e0206187. [PMID: 30335828 PMCID: PMC6193724 DOI: 10.1371/journal.pone.0206187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/07/2018] [Indexed: 01/14/2023] Open
Abstract
The rare branched-chain sugar apiose, once thought to only be present in the plant kingdom, was found in two bacterial species: Geminicoccus roseus and Xanthomonas pisi. Glycans with apiose residues were detected in aqueous methanol-soluble fractions as well as in the insoluble pellet fraction of X. pisi. Genes encoding bacterial uridine diphosphate apiose (UDP-apiose) synthases (bUASs) were characterized in these bacterial species, but the enzyme(s) involved in the incorporation of the apiose into glycans remained unknown. In the X. pisi genome two genes flanking the XpUAS were annotated as hypothetical glycosyltransferase (GT) proteins. The first GT (here on named XpApiT) belongs to GT family 90 and has a Leloir type B fold and a putative lipopolysaccharide-modifying (LPS) domain. The second GT (here on XpXylT) belongs to GT family 2 and has a type A fold. The XpXylT and XpApiT genes were cloned and heterologously expressed in E. coli. Analysis of nucleotide sugar extracts from E. coli expressing XpXylT or XpApiT with UAS showed that recombinant XpApiT utilized UDP-apiose and XpXylT utilized UDP-xylose as substrate. Indirect activity assay (UDP-Glo) revealed that XpApiT is an apiosyltransferase (ApiT) able to specifically use UDP-apiose. Further support for the apiosyltransferase activity was demonstrated by in microbe co-expression of UAS and XpApiT in E. coli showing the utilization of UDP-apiose to generate an apioside detectable in the pellet fraction. This work provides evidence that X. pisi developed the ability to synthesize an apioside of indeterminate function; however, the evolution of the bacterial ApiT remains to be determined. From genetic and evolutionary perspectives, the apiose operon may provide a unique opportunity to examine how genomic changes reflect ecological adaptation during the divergence of a bacterial group.
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Affiliation(s)
- James Amor Smith
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA, United States of America
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States of America
| | - Maor Bar-Peled
- Complex Carbohydrate Research Center (CCRC), University of Georgia, Athens, GA, United States of America
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, United States of America
- Department of Plant Biology, University of Georgia, Athens, GA, United States of America
- * E-mail:
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Salah Ud-Din AIM, Roujeinikova A. Flagellin glycosylation with pseudaminic acid in Campylobacter and Helicobacter: prospects for development of novel therapeutics. Cell Mol Life Sci 2018; 75:1163-1178. [PMID: 29080090 PMCID: PMC11105201 DOI: 10.1007/s00018-017-2696-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/10/2017] [Accepted: 10/24/2017] [Indexed: 02/08/2023]
Abstract
Many pathogenic bacteria require flagella-mediated motility to colonise and persist in their hosts. Helicobacter pylori and Campylobacter jejuni are flagellated epsilonproteobacteria associated with several human pathologies, including gastritis, acute diarrhea, gastric carcinoma and neurological disorders. In both species, glycosylation of flagellin with an unusual sugar pseudaminic acid (Pse) plays a crucial role in the biosynthesis of functional flagella, and thereby in bacterial motility and pathogenesis. Pse is found only in pathogenic bacteria. Its biosynthesis via six consecutive enzymatic steps has been extensively studied in H. pylori and C. jejuni. This review highlights the importance of flagella glycosylation and details structural insights into the enzymes in the Pse pathway obtained via a combination of biochemical, crystallographic, and mutagenesis studies of the enzyme-substrate and -inhibitor complexes. It is anticipated that understanding the underlying structural and molecular basis of the catalytic mechanisms of the Pse-synthesising enzymes will pave the way for the development of novel antimicrobials.
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Affiliation(s)
- Abu Iftiaf Md Salah Ud-Din
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Anna Roujeinikova
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia.
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
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35
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Rath CB, Schirmeister F, Figl R, Seeberger PH, Schäffer C, Kolarich D. Flagellin Glycoproteomics of the Periodontitis Associated Pathogen Selenomonas sputigena Reveals Previously Not Described O-glycans and Rhamnose Fragment Rearrangement Occurring on the Glycopeptides. Mol Cell Proteomics 2018; 17:721-736. [PMID: 29339411 PMCID: PMC5880101 DOI: 10.1074/mcp.ra117.000394] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/18/2017] [Indexed: 11/06/2022] Open
Abstract
Flagellated, Gram-negative, anaerobic, crescent-shaped Selenomonas species are colonizers of the digestive system, where they act at the interface between health and disease. Selenomonas sputigena is also considered a potential human periodontal pathogen, but information on its virulence factors and underlying pathogenicity mechanisms is scarce. Here we provide the first report of a Selenomonas glycoprotein, showing that S. sputigena produces a diversely and heavily O-glycosylated flagellin C9LY14 as a major cellular protein, which carries various hitherto undescribed rhamnose- and N-acetylglucosamine linked O-glycans in the range from mono- to hexasaccharides. A comprehensive glycomic and glycoproteomic assessment revealed extensive glycan macro- and microheterogeneity identified from 22 unique glycopeptide species. From the multiple sites of glycosylation, five were unambiguously identified on the 437-amino acid C9LY14 protein (Thr149, Ser182, Thr199, Thr259, and Ser334), the only flagellin protein identified. The O-glycans additionally showed modifications by methylation and putative acetylation. Some O-glycans carried hitherto undescribed residues/modifications as determined by their respective m/z values, reflecting the high diversity of native S. sputigena flagellin. We also found that monosaccharide rearrangement occurred during collision-induced dissociation (CID) of protonated glycopeptide ions. This effect resulted in pseudo Y1-glycopeptide fragment ions that indicated the presence of additional glycosylation sites on a single glycopeptide. CID oxonium ions and electron transfer dissociation, however, confirmed that just a single site was glycosylated, showing that glycan-to-peptide rearrangement can occur on glycopeptides and that this effect is influenced by the molecular nature of the glycan moiety. This effect was most pronounced with disaccharides. This study is the first report on O-linked flagellin glycosylation in a Selenomonas species, revealing that C9LY14 is one of the most heavily glycosylated flagellins described to date. This study contributes to our understanding of the largely under-investigated surface properties of oral bacteria. The data have been deposited to the ProteomeXchange with identifier PXD005859.
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Affiliation(s)
- Cornelia B. Rath
- From the ‡Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, 1190 Vienna, Austria
| | - Falko Schirmeister
- §Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany; ,¶Department of Biology, Chemistry, Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Rudolf Figl
- ‖Department of Chemistry, Division of Biochemistry, Universität für Bodenkultur Wien, 1190 Vienna, Austria
| | - Peter H. Seeberger
- §Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany; ,¶Department of Biology, Chemistry, Pharmacy, Institute of Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany
| | - Christina Schäffer
- From the ‡Department of NanoBiotechnology, NanoGlycobiology unit, Universität für Bodenkultur Wien, 1190 Vienna, Austria;
| | - Daniel Kolarich
- §Department of Biomolecular Systems, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany; .,**Institute for Glycomics, Gold Coast Campus, Griffith University, Queensland, 4222, Australia
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Yu C, Chen H, Tian F, Yang F, Yuan X, Yang C, He C. A ten gene-containing genomic island determines flagellin glycosylation: implication for its regulatory role in motility and virulence of Xanthomonas oryzae pv. oryzae. MOLECULAR PLANT PATHOLOGY 2018; 19:579-592. [PMID: 28213905 PMCID: PMC6638077 DOI: 10.1111/mpp.12543] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 02/06/2017] [Accepted: 02/13/2017] [Indexed: 05/19/2023]
Abstract
Flagellin glycosylation plays a crucial role in flagellar assembly, motility and virulence in several pathogenic bacteria. However, little is known about the genetic determinants and biological functions of flagellin glycosylation in Xanthomonas oryzae pv. oryzae (Xoo), the causal pathogen of bacterial blight of rice. Here, the structure, regulation and functions of a ten-gene cluster gigX (glycosylation island genes of Xoo), which was embedded in a flagellar regulon, were characterized. gigX1 to gigX10 encoded putative enzymes or proteins involved in glycan biosynthesis and transfer, including a nucleotide sugar transaminase, an acyl-carrier protein (ACP), a 3-oxoacyl-ACP synthase, a 3-oxoacyl-ACP reductase, a dehydrogenase, an acetyltransferase, a ring hydroxylating dioxygenase, a hypothetical protein, a methyltransferanse and a glycosyltransferase, respectively. The gigX genes were co-transcribed in an operon and up-regulated by the upstream σ54 factor RpoN2 and transcriptional activator FleQ. In-frame deletion of each gigX gene affected flagellin glycosylation modification, meaning that the unglycosylated flagellin of the mutants was smaller than the glycosylated flagellin of the wild-type. No significant changes in flagellar filament and motility were observed in the ΔgigX mutants, among which only ΔgigX6 displayed increased swimming ability. Importantly, all mutants, except ΔgigX9, showed significantly increased virulence and bacterial growth in the susceptible rice cultivar IR24, and ΔgigX1 and ΔgigX10 showed enhanced type III secretion system (T3SS)-related gene expression. Moreover, the glycosylated flagellin of the wild-type induced higher H2 O2 levels in rice leaves than did the unglycosylated flagellins of ΔgigX1 or ΔgigX10. Taken together, this study reveals that the gigX cluster determines flagellin glycosylation, and implicates the regulatory role of post-translational modification with the glycosylation, acetylation and methylation of flagellin in the regulation of motility and virulence of Xoo.
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Affiliation(s)
- Chao Yu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Huamin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Fang Tian
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Fenghuan Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
| | - Xiaochen Yuan
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI53211USA
| | - Ching‐Hong Yang
- Department of Biological SciencesUniversity of Wisconsin‐MilwaukeeMilwaukeeWI53211USA
| | - Chenyang He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing100193China
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Ajamian L, Melnychuk L, Jean-Pierre P, Zaharatos GJ. DNA Vaccine-Encoded Flagellin Can Be Used as an Adjuvant Scaffold to Augment HIV-1 gp41 Membrane Proximal External Region Immunogenicity. Viruses 2018; 10:E100. [PMID: 29495537 PMCID: PMC5869493 DOI: 10.3390/v10030100] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Revised: 02/22/2018] [Accepted: 02/23/2018] [Indexed: 02/07/2023] Open
Abstract
Flagellin's potential as a vaccine adjuvant has been increasingly explored over the last three decades. Monomeric flagellin proteins are the only known agonists of Toll-like receptor 5 (TLR5). This interaction evokes a pro-inflammatory state that impacts upon both innate and adaptive immunity. While pathogen associated molecular patterns (PAMPs) like flagellin have been used as stand-alone adjuvants that are co-delivered with antigen, some investigators have demonstrated a distinct advantage to incorporating antigen epitopes within the structure of flagellin itself. This approach has been particularly effective in enhancing humoral immune responses. We sought to use flagellin as both scaffold and adjuvant for HIV gp41 with the aim of eliciting antibodies to the membrane proximal external region (MPER). Accordingly, we devised a straightforward step-wise approach to select flagellin-antigen fusion proteins for gene-based vaccine development. Using plasmid DNA vector-based expression in mammalian cells, we demonstrate robust expression of codon-optimized full length and hypervariable region-deleted constructs of Salmonella enterica subsp. enterica serovar Typhi flagellin (FliC). An HIV gp41 derived sequence including the MPER (gp41607-683) was incorporated into various positions of these constructs and the expressed fusion proteins were screened for effective secretion, TLR5 agonist activity and adequate MPER antigenicity. We show that incorporation of gp41607-683 into a FliC-based scaffold significantly augments gp41607-683 immunogenicity in a TLR5 dependent manner and elicits modest MPER-specific humoral responses in a mouse model.
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Affiliation(s)
- Lara Ajamian
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada.
| | - Luca Melnychuk
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Division of Experimental Medicine, Department of Medicine, McGill University, Montréal, QC H4A 3J1, Canada.
| | - Patrick Jean-Pierre
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
| | - Gerasimos J Zaharatos
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Division of Infectious Disease, Department of Medicine & Division of Medical Microbiology, Department of Clinical Laboratory Medicine, Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
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Albers SV, Jarrell KF. The Archaellum: An Update on the Unique Archaeal Motility Structure. Trends Microbiol 2018; 26:351-362. [PMID: 29452953 DOI: 10.1016/j.tim.2018.01.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 01/08/2018] [Accepted: 01/19/2018] [Indexed: 11/24/2022]
Abstract
Each of the three domains of life exhibits a unique motility structure: while Bacteria use flagella, Eukarya employ cilia, and Archaea swim using archaella. Since the new name for the archaeal motility structure was proposed, in 2012, a significant amount of new data on the regulation of transcription of archaella operons, the structure and function of archaellum subunits, their interactions, and cryo-EM data on in situ archaellum complexes in whole cells have been obtained. These data support the notion that the archaellum is evolutionary and structurally unrelated to the flagellum, but instead is related to archaeal and bacterial type IV pili and emphasize that it is a motility structure unique to the Archaea.
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Affiliation(s)
- Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II - Microbiology, University of Freiburg, 79104 Freiburg, Germany.
| | - Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
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Fulton KM, Li J, Tomas JM, Smith JC, Twine SM. Characterizing bacterial glycoproteins with LC-MS. Expert Rev Proteomics 2018; 15:203-216. [PMID: 29400572 DOI: 10.1080/14789450.2018.1435276] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Though eukaryotic glycoproteins have been studied since their discovery in the 1930s, the first bacterial glycoprotein was not identified until the 1970s. As a result, their role in bacterial pathogenesis is still not well understood and they remain an understudied component of bacterial virulence. In recent years, mass spectrometry has emerged as a leading technology for the study of bacterial glycoproteins, largely due to its sensitivity and versatility. Areas covered: Identification and comprehensive characterization of bacterial glycoproteins usually requires multiple complementary mass spectrometry approaches, including intact protein analysis, top-down analysis, and bottom-up methods used in combination with specialized liquid chromatography. This review provides an overview of liquid chromatography separation technologies, as well as current and emerging mass spectrometry approaches used specifically for bacterial glycoprotein identification and characterization. Expert commentary: Bacterial glycoproteins may have significant clinical utility as a result of their unique structures and exposure on the surface of the cells. Better understanding of these glycoconjugates is an essential first step towards that goal. These often unique structures, and by extension the key enzymes involved in their synthesis, represent promising targets for novel antimicrobials, while unique carbohydrate structures may be used as antigens in vaccines or as biomarkers.
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Affiliation(s)
- Kelly M Fulton
- a Human Health Therapeutics Portfolio , National Research Council Canada , Ottawa , Canada
| | - Jianjun Li
- a Human Health Therapeutics Portfolio , National Research Council Canada , Ottawa , Canada
| | - Juan M Tomas
- b Departament de Microbiologia, Facultat de Biologia , Universitat de Barcelona , Barcelona , Spain
| | - Jeffrey C Smith
- c Department of Chemistry , Carleton University , Ottawa , Canada
| | - Susan M Twine
- a Human Health Therapeutics Portfolio , National Research Council Canada , Ottawa , Canada
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Sulzenbacher G, Roig-Zamboni V, Lebrun R, Guérardel Y, Murat D, Mansuelle P, Yamakawa N, Qian XX, Vincentelli R, Bourne Y, Wu LF, Alberto F. Glycosylate and move! The glycosyltransferase Maf is involved in bacterial flagella formation. Environ Microbiol 2017; 20:228-240. [DOI: 10.1111/1462-2920.13975] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/17/2017] [Accepted: 10/22/2017] [Indexed: 11/30/2022]
Affiliation(s)
| | | | - Régine Lebrun
- Plate-forme Protéomique; Institut de Microbiologie de la Méditerranée, FR3479 Aix-Marseille Université and Centre National de la Recherche Scientifique; Marseille 13402 France
| | - Yann Guérardel
- Unité de Glycobiologie Structurale et Fonctionnelle; UMR 8576 Université de Lille and Centre National de la Recherche Scientifique; Lille 59000 France
| | - Dorothée Murat
- Aix Marseille Univ, CNRS, LCB UMR7283; Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Organisms (LIA-MagMC); Centre National de la Recherche Scientifique; Marseille 13402 France
| | - Pascal Mansuelle
- Plate-forme Protéomique; Institut de Microbiologie de la Méditerranée, FR3479 Aix-Marseille Université and Centre National de la Recherche Scientifique; Marseille 13402 France
| | - Nao Yamakawa
- Unité de Glycobiologie Structurale et Fonctionnelle; UMR 8576 Université de Lille and Centre National de la Recherche Scientifique; Lille 59000 France
| | - Xin-Xin Qian
- Aix Marseille Univ, CNRS, LCB UMR7283; Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Organisms (LIA-MagMC); Centre National de la Recherche Scientifique; Marseille 13402 France
| | | | - Yves Bourne
- Aix Marseille Univ, CNRS, AFMB UMR7257; Marseille 13288 France
| | - Long-Fei Wu
- Aix Marseille Univ, CNRS, LCB UMR7283; Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Organisms (LIA-MagMC); Centre National de la Recherche Scientifique; Marseille 13402 France
| | - François Alberto
- Aix Marseille Univ, CNRS, LCB UMR7283; Marseille 13402 France
- International Associated Laboratory of Evolution and Development of Magnetotactic Organisms (LIA-MagMC); Centre National de la Recherche Scientifique; Marseille 13402 France
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Weller‐Stuart T, De Maayer P, Coutinho T. Pantoea ananatis: genomic insights into a versatile pathogen. MOLECULAR PLANT PATHOLOGY 2017; 18:1191-1198. [PMID: 27880983 PMCID: PMC6638271 DOI: 10.1111/mpp.12517] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
UNLABELLED Pantoea ananatis, a bacterium that is well known for its phytopathogenic characteristics, has been isolated from a myriad of ecological niches and hosts. Infection of agronomic crops, such as maize and rice, can result in substantial economic losses. In the last few years, much of the research performed on P. ananatis has been based on the sequencing and analysis of the genomes of strains isolated from different environments and with different lifestyles. In this review, we summarize the advances made in terms of pathogenicity determinants of phytopathogenic strains of P. ananatis and how this bacterium is able to adapt and survive in such a wide variety of habitats. The diversity and adaptability of P. ananatis can largely be attributed to the plasticity of its genome and the integration of mobile genetic elements on both the chromosome and plasmid. Furthermore, we discuss the recent interest in this species in various biotechnological applications. TAXONOMY Domain Bacteria; Class Gammaproteobacteria; Family Enterobacteriaceae; genus Pantoea; species ananatis. DISEASE SYMPTOMS Pantoea ananatis causes disease on a wide range of plants, and symptoms can range from dieback and stunted growth in Eucalyptus seedlings to chlorosis and bulb rotting in onions. DISEASE CONTROL Currently, the only methods of control of P. ananatis on most plant hosts are the use of resistant clones and cultivars or the eradication of infected plant material. The use of lytic bacteriophages on certain host plants, such as rice, has also achieved a measure of success.
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Affiliation(s)
- Tania Weller‐Stuart
- Forestry and Agricultural Biotechnology Institute (FABI), Department of MicrobiologyUniversity of PretoriaPretoria0002South Africa
| | - Pieter De Maayer
- School of Molecular and Cell BiologyUniversity of the WitwatersrandJohannesburg2050South Africa
| | - Teresa Coutinho
- Forestry and Agricultural Biotechnology Institute (FABI), Department of MicrobiologyUniversity of PretoriaPretoria0002South Africa
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42
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Bunker JJ, Erickson SA, Flynn TM, Henry C, Koval JC, Meisel M, Jabri B, Antonopoulos DA, Wilson PC, Bendelac A. Natural polyreactive IgA antibodies coat the intestinal microbiota. Science 2017; 358:science.aan6619. [PMID: 28971969 DOI: 10.1126/science.aan6619] [Citation(s) in RCA: 287] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/19/2017] [Indexed: 12/11/2022]
Abstract
Large quantities of immunoglobulin A (IgA) are constitutively secreted by intestinal plasma cells to coat and contain the commensal microbiota, yet the specificity of these antibodies remains elusive. Here we profiled the reactivities of single murine IgA plasma cells by cloning and characterizing large numbers of monoclonal antibodies. IgAs were not specific to individual bacterial taxa but rather polyreactive, with broad reactivity to a diverse, but defined, subset of microbiota. These antibodies arose at low frequencies among naïve B cells and were selected into the IgA repertoire upon recirculation in Peyer's patches. This selection process occurred independent of microbiota or dietary antigens. Furthermore, although some IgAs acquired somatic mutations, these did not substantially influence their reactivity. These findings reveal an endogenous mechanism driving homeostatic production of polyreactive IgAs with innate specificity to microbiota.
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Affiliation(s)
- Jeffrey J Bunker
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.,Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Steven A Erickson
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.,Department of Pathology, University of Chicago, Chicago, IL 60637, USA
| | - Theodore M Flynn
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Carole Henry
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.,Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Jason C Koval
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Marlies Meisel
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.,Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Bana Jabri
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.,Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Dionysios A Antonopoulos
- Biosciences Division, Argonne National Laboratory, Argonne, IL 60439, USA.,Department of Medicine, University of Chicago, Chicago, IL 60637, USA.,Institute for Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA
| | - Patrick C Wilson
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA.,Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Albert Bendelac
- Committee on Immunology, University of Chicago, Chicago, IL 60637, USA. .,Department of Pathology, University of Chicago, Chicago, IL 60637, USA
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43
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The invasome of Salmonella Dublin as revealed by whole genome sequencing. BMC Infect Dis 2017; 17:544. [PMID: 28778189 PMCID: PMC5544996 DOI: 10.1186/s12879-017-2628-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 07/21/2017] [Indexed: 12/13/2022] Open
Abstract
Background Salmonella enterica serovar Dublin is a zoonotic infection that can be transmitted from cattle to humans through consumption of contaminated milk and milk products. Outbreaks of human infections by S. Dublin have been reported in several countries including high-income countries. A high proportion of S. Dublin cases in humans are associated with invasive disease and systemic illness. The genetic basis of virulence in S. Dublin is not well characterized. Methods Whole genome sequencing was applied to a set of clinical invasive and non-invasive S. Dublin isolates from different countries in order to characterize the putative genetic determinants involved in the virulence and invasiveness of S. Dublin in humans. Results We identified several virulence factors that form the bacterial invasome and may contribute to increasing bacterial virulence and pathogenicity including mainly Gifsy-2 prophage, two different type 6 secretion systems (T6SSs) harbored by Salmonella pathogenicity islands; SPI-6 and SPI-19 respectively and virulence genes; ggt and PagN. Although Vi antigen and the virulence plasmid have been reported previously to contribute to the virulence of S. Dublin we did not detect them in all invasive isolates indicating that they are not the main virulence determinants in S. Dublin. Conclusion Several virulence factors within the genome of S. Dublin might contribute to the ability of S. Dublin to invade humans’ blood but there were no genomic markers that differentiate invasive from non-invasive isolates suggesting that host immune response play a crucial role in the clinical outcome of S. Dublin infection. Electronic supplementary material The online version of this article (doi:10.1186/s12879-017-2628-x) contains supplementary material, which is available to authorized users.
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44
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Radomska KA, Wösten MMSM, Ordoñez SR, Wagenaar JA, van Putten JPM. Importance of Campylobacter jejuni FliS and FliW in Flagella Biogenesis and Flagellin Secretion. Front Microbiol 2017; 8:1060. [PMID: 28659885 PMCID: PMC5466977 DOI: 10.3389/fmicb.2017.01060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/29/2017] [Indexed: 12/11/2022] Open
Abstract
Flagella-driven motility enables bacteria to reach their favorable niche within the host. The human foodborne pathogen Campylobacter jejuni produces two heavily glycosylated structural flagellins (FlaA and FlaB) that form the flagellar filament. It also encodes the non-structural FlaC flagellin which is secreted through the flagellum and has been implicated in host cell invasion. The mechanisms that regulate C. jejuni flagellin biogenesis and guide the proteins to the export apparatus are different from those in most other enteropathogens and are not fully understood. This work demonstrates the importance of the putative flagellar protein FliS in C. jejuni flagella assembly. A constructed fliS knockout strain was non-motile, displayed reduced levels of FlaA/B and FlaC flagellin, and carried severely truncated flagella. Pull-down and Far Western blot assays showed direct interaction of FliS with all three C. jejuni flagellins (FlaA, FlaB, and FlaC). This is in contrast to, the sensor and regulator of intracellular flagellin levels, FliW, which bound to FlaA and FlaB but not to FlaC. The FliS protein but not FliW preferred binding to glycosylated C. jejuni flagellins rather than to their non-glycosylated recombinant counterparts. Mapping of the binding region of FliS and FliW using a set of flagellin fragments showed that the C-terminal subdomain of the flagellin was required for FliS binding, whereas the N-terminal subdomain was essential for FliW binding. The separate binding subdomains required for FliS and FliW, the different substrate specificity, and the differential preference for binding of glycosylated flagellins ensure optimal processing and assembly of the C. jejuni flagellins.
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Affiliation(s)
- Katarzyna A Radomska
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands
| | - Marc M S M Wösten
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands
| | - Soledad R Ordoñez
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands
| | - Jaap A Wagenaar
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands.,Wageningen Bioveterinary ResearchLelystad, Netherlands.,WHO Collaborating Centre for Campylobacter/OIE Reference Laboratory for CampylobacteriosisUtrecht, Netherlands
| | - Jos P M van Putten
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands.,WHO Collaborating Centre for Campylobacter/OIE Reference Laboratory for CampylobacteriosisUtrecht, Netherlands
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45
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Kao CY, Chen JW, Wang S, Sheu BS, Wu JJ. The Helicobacter pylori J99 jhp0106 Gene, under the Control of the CsrA/RpoN Regulatory System, Modulates Flagella Formation and Motility. Front Microbiol 2017; 8:483. [PMID: 28400753 PMCID: PMC5368276 DOI: 10.3389/fmicb.2017.00483] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 03/08/2017] [Indexed: 12/11/2022] Open
Abstract
CsrA has been shown to positively control the expression of flagella-related genes, including flaA and flaB, through regulating expression of an alternative sigma factor RpoN in Helicobacter pylori J99. Here, we aimed to characterize the CsrA regulatory system by comparative transcriptomic analysis carried out with RNA-seq on strain J99 and a csrA mutant. Fifty-three genes in the csrA mutant were found to be differentially expressed compared with the wild-type. Among CsrA-regulated genes, jhp0106, with unclear function, was found located downstream of flaB in the J99 genome. We hypothesized that flaB-jhp0106 is in an operon under the control of RpoN binding to the flaB promoter. The RT-qPCR results showed the expression of jhp0106 was decreased 76 and 92% in the csrA and rpoN mutants, respectively, compared to the wild-type. Moreover, mutations of the RpoN binding site in the flaB promoter region resulted in decreased expression of flaB and jhp0106 and deficient motility. Three-dimensional structure modeling results suggested that Jhp0106 was a glycosyltransferase. The role of jhp0106 in H. pylori was further investigated by constructing the jhp0106 mutant and revertant strains. A soft-agar motility assay and transmission electron microscope were used to determine the motility and flagellar structure of examined strains, and the results showed the loss of motility and flagellar structure in jhp0106 mutant J99. In conclusion, we found jhp0106, under the control of the CsrA/RpoN regulatory system, plays a critical role in H. pylori flagella formation.
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Affiliation(s)
- Cheng-Yen Kao
- Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang Ming University Taipei, Taiwan
| | - Jenn-Wei Chen
- Center of Infectious Disease and Signaling Research, National Cheng Kung UniversityTainan, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Shuying Wang
- Center of Infectious Disease and Signaling Research, National Cheng Kung UniversityTainan, Taiwan; Department of Microbiology and Immunology, College of Medicine, National Cheng Kung UniversityTainan, Taiwan
| | - Bor-Shyang Sheu
- Department of Internal Medicine, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung UniversityTainan, Taiwan; Department of Internal Medicine, Tainan Hospital, Ministry of Health & WelfareTainan, Taiwan
| | - Jiunn-Jong Wu
- Department of Biotechnology and Laboratory Science in Medicine, School of Biomedical Science and Engineering, National Yang Ming University Taipei, Taiwan
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46
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Eichler J, Koomey M. Sweet New Roles for Protein Glycosylation in Prokaryotes. Trends Microbiol 2017; 25:662-672. [PMID: 28341406 DOI: 10.1016/j.tim.2017.03.001] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 02/19/2017] [Accepted: 03/01/2017] [Indexed: 12/29/2022]
Abstract
Long-held to be a post-translational modification unique to Eukarya, it is now clear that both Bacteria and Archaea also perform protein glycosylation, namely the covalent attachment of mono- to polysaccharides to specific protein targets. At the same time, many of the roles assigned to this protein-processing event in eukaryotes, such as guiding protein folding/quality control, intracellular trafficking, dictating cellular recognition events and others, do not apply or are even irrelevant to prokaryotes. As such, protein glycosylation must serve novel functions in Bacteria and Archaea. Recent efforts have begun to elucidate some of these prokaryote-specific roles, which are addressed in this review.
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Affiliation(s)
- Jerry Eichler
- Department of Life Sciences, Ben Gurion University of the Negev, Beersheva 84105, Israel.
| | - Michael Koomey
- Department of Biosciences, University of Oslo, 0316 Oslo, Norway
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Jiang YL, Jin H, Yang HB, Zhao RL, Wang S, Chen Y, Zhou CZ. Defining the enzymatic pathway for polymorphic O-glycosylation of the pneumococcal serine-rich repeat protein PsrP. J Biol Chem 2017; 292:6213-6224. [PMID: 28246170 DOI: 10.1074/jbc.m116.770446] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/17/2017] [Indexed: 12/30/2022] Open
Abstract
Protein O-glycosylation is an important post-translational modification in all organisms, but deciphering the specific functions of these glycans is difficult due to their structural complexity. Understanding the glycosylation of mucin-like proteins presents a particular challenge as they are modified numerous times with both the enzymes involved and the glycosylation patterns being poorly understood. Here we systematically explored the O-glycosylation pathway of a mucin-like serine-rich repeat protein PsrP from the human pathogen Streptococcus pneumoniae TIGR4. Previous works have assigned the function of 3 of the 10 glycosyltransferases thought to modify PsrP, GtfA/B, and Gtf3 as catalyzing the first two reactions to form a unified disaccharide core structure. We now use in vivo and in vitro glycosylation assays combined with hydrolytic activity assays to identify the glycosyltransferases capable of decorating this core structure in the third and fourth steps of glycosylation. Specifically, the full-length GlyE and GlyG proteins and the GlyD DUF1792 domain participate in both steps, whereas full-length GlyA and the GlyD GT8 domain catalyze only the fourth step. Incorporation of different sugars to the disaccharide core structure at multiple sites along the serine-rich repeats results in a highly polymorphic product. Furthermore, crystal structures of apo- and UDP-complexed GlyE combined with structural analyses reveal a novel Rossmann-fold "add-on" domain that we speculate to function as a universal module shared by GlyD, GlyE, and GlyA to forward the peptide acceptor from one enzyme to another. These findings define the complete glycosylation pathway of a bacterial glycoprotein and offer a testable hypothesis of how glycosyltransferase coordination facilitates glycan assembly.
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Affiliation(s)
- Yong-Liang Jiang
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and.,Key Laboratory of Structural Biology, Chinese Academy of Science, Hefei, Anhui 230027, China
| | - Hua Jin
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and.,Key Laboratory of Structural Biology, Chinese Academy of Science, Hefei, Anhui 230027, China
| | - Hong-Bo Yang
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and.,Key Laboratory of Structural Biology, Chinese Academy of Science, Hefei, Anhui 230027, China
| | - Rong-Li Zhao
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and.,Key Laboratory of Structural Biology, Chinese Academy of Science, Hefei, Anhui 230027, China
| | - Shiliang Wang
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and
| | - Yuxing Chen
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and .,Key Laboratory of Structural Biology, Chinese Academy of Science, Hefei, Anhui 230027, China
| | - Cong-Zhao Zhou
- From the Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China and .,Key Laboratory of Structural Biology, Chinese Academy of Science, Hefei, Anhui 230027, China
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48
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Nagano K, Hasegawa Y, Yoshida Y, Yoshimura F. Comparative analysis of motility and other properties of Treponema denticola strains. Microb Pathog 2016; 102:82-88. [PMID: 27914958 DOI: 10.1016/j.micpath.2016.11.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Revised: 10/18/2016] [Accepted: 11/29/2016] [Indexed: 01/27/2023]
Abstract
The periodontitis-associated pathogen Treponema denticola is a spirochetal bacterium that swims by rotating its cell body like a corkscrew using periplasmic flagella. We compared physiologic and pathogenic properties, including motility, in four strains of T. denticola. Phase-contrast microscopy showed differential motility between the strains; ATCC 35404 showed the highest motility, followed by ATCC 33521, and the remaining two strains (ATCC 35405 and ATCC 33520) showed the lowest motility. Transmission electron microscopy showed that the low motility strains exhibited extracellular flagellar protrusions resulting from elongated flagella. Treponemal flagellar filaments are composed of three flagellins of FlaB1, FlaB2 and FlaB3. FlaB1 expression was comparable between the strains, whereas FlaB2 expression was lowest in ATCC 35404. FlaB3 expression varied among strains, with ATCC 35405, ATCC 33520, ATCC 33521, and ATCC 35404 showing the highest to lowest expression levels, respectively. Additionally, the low motility strains showed faster electrophoretic mobility of FlaB3, suggesting that posttranslational modifications of these proteins may have varied, because the amino acid sequences of FlaB3 were identical between the strains. These results suggest that inappropriate expression of FlaB2 and FlaB3 caused the unusual elongation of flagella that resulted in decreased motility. Furthermore, the low motility strains grew to higher bacterial density, and showed greater chymotrypsin-like protease activity, and more bacterial cells associated with gingival epithelial cells in comparison with the high motility strains. There may be a relationship between motility and these properties, but the genetic factors underlying this association remain unclear.
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Affiliation(s)
- Keiji Nagano
- Department of Microbiology, School of Dentistry, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan.
| | - Yoshiaki Hasegawa
- Department of Microbiology, School of Dentistry, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Yasuo Yoshida
- Department of Microbiology, School of Dentistry, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Fuminobu Yoshimura
- Department of Microbiology, School of Dentistry, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
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49
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De Maayer P, Cowan DA. Comparative genomic analysis of the flagellin glycosylation island of the Gram-positive thermophile Geobacillus. BMC Genomics 2016; 17:913. [PMID: 27842516 PMCID: PMC5109656 DOI: 10.1186/s12864-016-3273-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 11/05/2016] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Protein glycosylation involves the post-translational attachment of sugar chains to target proteins and has been observed in all three domains of life. Post-translational glycosylation of flagellin, the main structural protein of the flagellum, is a common characteristic among many Gram-negative bacteria and Archaea. Several distinct functions have been ascribed to flagellin glycosylation, including stabilisation and maintenance of the flagellar filament, motility, surface recognition, adhesion, and virulence. However, little is known about this trait among Gram-positive bacteria. RESULTS Using comparative genomic approaches the flagellin glycosylation loci of multiple strains of the Gram-positive thermophilic genus Geobacillus were identified and characterized. Eighteen of thirty-six compared strains of the genus carry these loci, which show evidence of horizontal acquisition. The Geobacillus flagellin glycosylation islands (FGIs) can be clustered into five distinct types, which are predicted to encode highly variable glycans decorated with distinct and heavily modified sugars. CONCLUSIONS Our comparative genomic analyses showed that, while not universal, flagellin glycosylation islands are relatively common among members of the genus Geobacillus and that the encoded flagellin glycans are highly variable. This suggests that flagellin glycosylation plays an important role in the lifestyles of members of this thermophilic genus.
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Affiliation(s)
- Pieter De Maayer
- School of Molecular and Cell Biology, University of the Witwatersrand, Private Bag 3, Wits, 2050, Johannesburg, South Africa.
| | - Don A Cowan
- Centre for Microbial Ecology and Genomics, Genomics Research Institute, University of Pretoria, Pretoria, 0002, South Africa
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50
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Kurniyati K, Kelly JF, Vinogradov E, Robotham A, Tu Y, Wang J, Liu J, Logan SM, Li C. A novel glycan modifies the flagellar filament proteins of the oral bacterium Treponema denticola. Mol Microbiol 2016; 103:67-85. [PMID: 27696564 DOI: 10.1111/mmi.13544] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2016] [Indexed: 01/12/2023]
Abstract
While protein glycosylation has been reported in several spirochetes including the syphilis bacterium Treponema pallidum and Lyme disease pathogen Borrelia burgdorferi, the pertinent glycan structures and their roles remain uncharacterized. Herein, a novel glycan with an unusual chemical composition and structure in the oral spirochete Treponema denticola, a keystone pathogen of periodontitis was reported. The identified glycan of mass 450.2 Da is composed of a monoacetylated nonulosonic acid (Non) with a novel extended N7 acyl modification, a 2-methoxy-4,5,6-trihydroxy-hexanoyl residue in which the Non has a pseudaminic acid configuration (L-glycero-L-manno) and is β-linked to serine or threonine residues. This novel glycan modifies the flagellin proteins (FlaBs) of T. denticola by O-linkage at multiple sites near the D1 domain, a highly conserved region of bacterial flagellins that interact with Toll-like receptor 5. Furthermore, mutagenesis studies demonstrate that the glycosylation plays an essential role in the flagellar assembly and motility of T. denticola. To our knowledge, this novel glycan and its unique modification sites have not been reported previously in any bacteria.
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Affiliation(s)
- Kurni Kurniyati
- Department of Oral Biology, The State University of New York at Buffalo, New York, NY, 14214, USA
| | - John F Kelly
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Evgeny Vinogradov
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Anna Robotham
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Youbing Tu
- Department of Oral Biology, The State University of New York at Buffalo, New York, NY, 14214, USA
| | - Juyu Wang
- Department of Pathology and Laboratory Medicine, McGovern Medical School at UT Health Science Center, Houston, TX, 77030, USA
| | - Jun Liu
- Department of Pathology and Laboratory Medicine, McGovern Medical School at UT Health Science Center, Houston, TX, 77030, USA
| | - Susan M Logan
- Vaccine Program, Human Health Therapeutics, National Research Council, Ottawa, Ontario, K1A 0R6, Canada
| | - Chunhao Li
- Department of Oral Biology, The State University of New York at Buffalo, New York, NY, 14214, USA.,Department of Microbiology and Immunology, The State University of New York at Buffalo, New York, NY, 14214, USA
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