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Novak J, King RG, Yother J, Renfrow MB, Green TJ. O-glycosylation of IgA1 and the pathogenesis of an autoimmune disease IgA nephropathy. Glycobiology 2024; 34:cwae060. [PMID: 39095059 PMCID: PMC11442006 DOI: 10.1093/glycob/cwae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/21/2024] [Accepted: 08/01/2024] [Indexed: 08/04/2024] Open
Abstract
IgA nephropathy is a kidney disease characterized by deposition of immune complexes containing abnormally O-glycosylated IgA1 in the glomeruli. Specifically, some O-glycans are missing galactose that is normally β1,3-linked to N-acetylgalactosamine of the core 1 glycans. These galactose-deficient IgA1 glycoforms are produced by IgA1-secreting cells due to a dysregulated expression and activity of several glycosyltransferases. Galactose-deficient IgA1 in the circulation of patients with IgA nephropathy is bound by IgG autoantibodies and the resultant immune complexes can contain additional proteins, such as complement C3. These complexes, if not removed from the circulation, can enter the glomerular mesangium, activate the resident mesangial cells, and induce glomerular injury. In this review, we briefly summarize clinical and pathological features of IgA nephropathy, review normal and aberrant IgA1 O-glycosylation pathways, and discuss the origins and potential significance of natural anti-glycan antibodies, namely those recognizing N-acetylgalactosamine. We also discuss the features of autoantibodies specific for galactose-deficient IgA1 and the characteristics of pathogenic immune complexes containing IgA1 and IgG. In IgA nephropathy, kidneys are injured by IgA1-containing immune complexes as innocent bystanders. Most patients with IgA nephropathy progress to kidney failure and require dialysis or transplantation. Moreover, most patients after transplantation experience a recurrent disease. Thus, a better understanding of the pathogenetic mechanisms is needed to develop new disease-specific treatments.
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Affiliation(s)
- Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, United States
| | - R Glenn King
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, United States
| | - Janet Yother
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, United States
| | - Matthew B Renfrow
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 720 20th Street South, Birmingham, AL 35294, United States
| | - Todd J Green
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, United States
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2
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Wu R, Nahm M, Yang J, Bush CA, Wu H. Identification and genetic engineering of pneumococcal capsule-like polysaccharides in commensal oral streptococci. Microbiol Spectr 2024; 12:e0188523. [PMID: 38488366 PMCID: PMC10986556 DOI: 10.1128/spectrum.01885-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 08/28/2023] [Indexed: 04/06/2024] Open
Abstract
Capsular polysaccharides (CPS) in Streptococcus pneumoniae are pivotal for bacterial virulence and present extensive diversity. While oral streptococci show pronounced antigenicity toward pneumococcal capsule-specific sera, insights into evolution of capsule diversity remain limited. This study reports a pneumococcal CPS-like genetic locus in Streptococcus parasanguinis, a predominant oral Streptococcus. The discovered locus comprises 15 genes, mirroring high similarity to those from the Wzy-dependent CPS locus of S. pneumoniae. Notably, S. parasanguinis elicited a reaction with pneumococcal 19B antiserum. Through nuclear magnetic resonance analysis, we ascertained that its CPS structure matches the chemical composition of the pneumococcal 19B capsule. By introducing the glucosyltransferase gene cps19cS from a pneumococcal serotype 19C, we successfully transformed S. parasanguinis antigenicity from 19B to 19C. Furthermore, substituting serotype-specific genes, cpsI and cpsJ, with their counterparts from pneumococcal serotype 19A and 19F enabled S. parasanguinis to generate 19A- and 19F-specific CPS, respectively. These findings underscore that S. parasanguinis harbors a versatile 19B-like CPS adaptable to other serotypes. Remarkably, after deleting the locus's initial gene, cpsE, responsible for sugar transfer, we noted halted CPS production, elongated bacterial chains, and diminished biofilm formation. A similar phenotype emerged with the removal of the distinct gene cpsZ, which encodes a putative autolysin. These data highlight the importance of S. parasanguinis CPS for biofilm formation and propose a potential shared ancestry of its CPS locus with S. pneumoniae. IMPORTANCE Diverse capsules from Streptococcus pneumoniae are vital for bacterial virulence and pathogenesis. Oral streptococci show strong responses to a wide range of pneumococcal capsule-specific sera. Yet, the evolution of this capsule diversity in relation to microbe-host interactions remains underexplored. Our research delves into the connection between commensal oral streptococcal and pneumococcal capsules, highlighting the potential for gene transfer and evolution of various capsule types. Understanding the genetic and evolutionary factors that drive capsule diversity in S. pneumoniae and its related oral species is essential for the development of effective pneumococcal vaccines. The present findings provide fresh perspectives on the cross-reactivity between commensal streptococci and S. pneumoniae, its influence on bacteria-host interactions, and the development of new strategies to manage and prevent pneumococcal illnesses by targeting and modulating commensal streptococci.
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Affiliation(s)
- Ren Wu
- Department of Pediatric Dentistry, University of Alabama at Birmingham, School of Dentistry, Birmingham, Alabama, USA
| | - Moon Nahm
- Department of Medicine, University of Alabama at Birmingham, School of Medicine, Birmingham, Alabama, USA
| | - Jinghua Yang
- Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - C. Allen Bush
- Department of Chemistry and Biochemistry, University of Maryland at Baltimore, Baltimore, Maryland, USA
| | - Hui Wu
- Department of Pediatric Dentistry, University of Alabama at Birmingham, School of Dentistry, Birmingham, Alabama, USA
- Division of Biomaterial and Biomedical Sciences, Oregon Health & Science University School of Dentistry, Portland, Oregon, USA
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3
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Cinar MS, Niyas A, Avci FY. Serine-rich repeat proteins: well-known yet little-understood bacterial adhesins. J Bacteriol 2024; 206:e0024123. [PMID: 37975670 PMCID: PMC10810200 DOI: 10.1128/jb.00241-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023] Open
Abstract
Serine-rich-repeat proteins (SRRPs) are large mucin-like glycoprotein adhesins expressed by a plethora of pathogenic and symbiotic Gram-positive bacteria. SRRPs play major functional roles in bacterial-host interactions, like adhesion, aggregation, biofilm formation, virulence, and pathogenesis. Through their functional roles, SRRPs aid in the development of host microbiomes but also diseases like infective endocarditis, otitis media, meningitis, and pneumonia. SRRPs comprise shared domains across different species, including two or more heavily O-glycosylated long stretches of serine-rich repeat regions. With loci that can be as large as ~40 kb and can encode up to 10 distinct glycosyltransferases that specifically facilitate SRRP glycosylation, the SRRP loci makes up a significant portion of the bacterial genome. The significance of SRRPs and their glycans in host-microbe communications is becoming increasingly evident. Studies are beginning to reveal the glycosylation pathways and mature O-glycans presented by SRRPs. Here we review the glycosylation machinery of SRRPs across species and discuss the functional roles and clinical manifestations of SRRP glycosylation.
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Affiliation(s)
- Mukaddes S. Cinar
- Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Afaq Niyas
- Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Fikri Y. Avci
- Department of Biochemistry, Emory Vaccine Center, Emory University School of Medicine, Atlanta, Georgia, USA
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4
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Chan JM, Gori A, Nobbs AH, Heyderman RS. Streptococcal Serine-Rich Repeat Proteins in Colonization and Disease. Front Microbiol 2020; 11:593356. [PMID: 33193266 PMCID: PMC7661464 DOI: 10.3389/fmicb.2020.593356] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/12/2020] [Indexed: 01/10/2023] Open
Abstract
Glycosylation of proteins, previously thought to be absent in prokaryotes, is increasingly recognized as important for both bacterial colonization and pathogenesis. For mucosal pathobionts, glycoproteins that function as cell wall-associated adhesins facilitate interactions with mucosal surfaces, permitting persistent adherence, invasion of deeper tissues and transition to disease. This is exemplified by Streptococcus pneumoniae and Streptococcus agalactiae, which can switch from being relatively harmless members of the mucosal tract microbiota to bona fide pathogens that cause life-threatening diseases. As part of their armamentarium of virulence factors, streptococci encode a family of large, glycosylated serine-rich repeat proteins (SRRPs) that facilitate binding to various tissue types and extracellular matrix proteins. This minireview focuses on the roles of S. pneumoniae and S. agalactiae SRRPs in persistent colonization and the transition to disease. The potential of utilizing SRRPs as vaccine targets will also be discussed.
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Affiliation(s)
- Jia Mun Chan
- NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Andrea Gori
- NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, University College London, London, United Kingdom
| | - Angela H. Nobbs
- Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Robert S. Heyderman
- NIHR Mucosal Pathogens Research Unit, Division of Infection and Immunity, University College London, London, United Kingdom
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5
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Streptococcus oralis subsp. dentisani Produces Monolateral Serine-Rich Repeat Protein Fibrils, One of Which Contributes to Saliva Binding via Sialic Acid. Infect Immun 2019; 87:IAI.00406-19. [PMID: 31308084 DOI: 10.1128/iai.00406-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 07/08/2019] [Indexed: 12/27/2022] Open
Abstract
Our studies reveal that the oral colonizer and cause of infective endocarditis Streptococcus oralis subsp. dentisani displays a striking monolateral distribution of surface fibrils. Furthermore, our data suggest that these fibrils impact the structure of adherent bacterial chains. Mutagenesis studies indicate that these fibrils are dependent on three serine-rich repeat proteins (SRRPs), here named fibril-associated protein A (FapA), FapB, and FapC, and that each SRRP forms a different fibril with a distinct distribution. SRRPs are a family of bacterial adhesins that have diverse roles in adhesion and that can bind to different receptors through modular nonrepeat region domains. Amino acid sequence and predicted structural similarity searches using the nonrepeat regions suggested that FapA may contribute to interspecies interactions, that FapA and FapB may contribute to intraspecies interactions, and that FapC may contribute to sialic acid binding. We demonstrate that a fapC mutant was significantly reduced in binding to saliva. We confirmed a role for FapC in sialic acid binding by demonstrating that the parental strain was significantly reduced in adhesion upon addition of a recombinantly expressed, sialic acid-specific, carbohydrate binding module, while the fapC mutant was not reduced. However, mutation of a residue previously shown to be essential for sialic acid binding did not decrease bacterial adhesion, leaving the precise mechanism of FapC-mediated adhesion to sialic acid to be defined. We also demonstrate that the presence of any one of the SRRPs is sufficient for efficient biofilm formation. Similar structures were observed on all infective endocarditis isolates examined, suggesting that this distribution is a conserved feature of this S. oralis subspecies.
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6
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Kristensen MF, Zeng G, Neu TR, Meyer RL, Baelum V, Schlafer S. Osteopontin adsorption to Gram-positive cells reduces adhesion forces and attachment to surfaces under flow. J Oral Microbiol 2017; 9:1379826. [PMID: 29081915 PMCID: PMC5646589 DOI: 10.1080/20002297.2017.1379826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/07/2017] [Indexed: 01/27/2023] Open
Abstract
The bovine milk protein osteopontin (OPN) may be an efficient means to prevent bacterial adhesion to dental tissues and control biofilm formation. This study sought to determine to what extent OPN impacts adhesion forces and surface attachment of different bacterial strains involved in dental caries or medical device–related infections. It further investigated if OPN’s effect on adhesion is caused by blocking the accessibility of glycoconjugates on bacterial surfaces. Bacterial adhesion was determined in a shear-controlled flow cell system in the presence of different concentrations of OPN, and interaction forces of single bacteria were quantified using single-cell force spectroscopy before and after OPN exposure. Moreover, the study investigated OPN’s effect on the accessibility of cell surface glycoconjugates through fluorescence lectin-binding analysis. OPN strongly affected bacterial adhesion in a dose-dependent manner for all investigated species (Actinomyces naeslundii, Actinomyces viscosus, Lactobacillus paracasei subsp. paracasei, Staphylococcus epidermidis, Streptococcus mitis, and Streptococcus oralis). Likewise, adhesion forces decreased after OPN treatment. No effect of OPN on the lectin-accessibility to glycoconjugates was found. OPN reduces the adhesion and adhesion force/energy of a variety of bacteria and has a potential therapeutic use for biofilm control. OPN acts upon bacterial adhesion without blocking cell surface glycoconjugates.
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Affiliation(s)
- M F Kristensen
- Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - G Zeng
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark
| | - T R Neu
- Department of River Ecology, Helmholtz Centre for Environmental Research - UFZ, Magdeburg, Germany
| | - R L Meyer
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Aarhus, Denmark.,Section of Microbiology, Department of Bioscience;Aarhus University, Aarhus, Denmark
| | - V Baelum
- Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark
| | - S Schlafer
- Department of Dentistry and Oral Health, Aarhus University, Aarhus, Denmark.,Section of Microbiology, Department of Bioscience;Aarhus University, Aarhus, Denmark
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7
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Couvigny B, Lapaque N, Rigottier-Gois L, Guillot A, Chat S, Meylheuc T, Kulakauskas S, Rohde M, Mistou MY, Renault P, Doré J, Briandet R, Serror P, Guédon E. Three glycosylated serine-rich repeat proteins play a pivotal role in adhesion and colonization of the pioneer commensal bacterium,Streptococcus salivarius. Environ Microbiol 2017; 19:3579-3594. [DOI: 10.1111/1462-2920.13853] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/29/2017] [Accepted: 06/30/2017] [Indexed: 01/25/2023]
Affiliation(s)
- Benoit Couvigny
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Nicolas Lapaque
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Lionel Rigottier-Gois
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Alain Guillot
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Sophie Chat
- INRA, Plateforme MIMA2; Jouy-en-josas France
| | - Thierry Meylheuc
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
- INRA, Plateforme MIMA2; Jouy-en-josas France
| | - Saulius Kulakauskas
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Manfred Rohde
- HZI, Helmholtz Centre for Infection Research; Braunschweig Germany
| | - Michel-Yves Mistou
- Laboratory for Food Safety; Université Paris-Est, ANSES; Maisons-Alfort France
| | - Pierre Renault
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Joel Doré
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Romain Briandet
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Pascale Serror
- MICALIS Institute, INRA, AgroParisTech; Université Paris-Saclay; Jouy-en-Josas France
| | - Eric Guédon
- STLO, UMR1253, INRA, Agrocampus Ouest; Rennes France
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8
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Zhu F, Zhang H, Yang T, Haslam SM, Dell A, Wu H. Engineering and Dissecting the Glycosylation Pathway of a Streptococcal Serine-rich Repeat Adhesin. J Biol Chem 2017; 291:27354-27363. [PMID: 28039332 PMCID: PMC5207161 DOI: 10.1074/jbc.m116.752998] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 11/11/2016] [Indexed: 11/24/2022] Open
Abstract
Serine-rich repeat glycoproteins (SRRPs) are conserved in Gram-positive bacteria. They are crucial for modulating biofilm formation and bacterial-host interactions. Glycosylation of SRRPs plays a pivotal role in the process; thus understanding the glycosyltransferases involved is key to identifying new therapeutic drug targets. The glycosylation of Fap1, an SRRP of Streptococcus parasanguinis, is mediated by a gene cluster consisting of six genes: gtf1, gtf2, gly, gtf3, dGT1, and galT2. Mature Fap1 glycan possesses the sequence of Rha1–3Glc1-(Glc1–3GlcNAc1)-2,6-Glc1–6GlcNAc. Gtf12, Gtf3, and dGT1 are responsible for the first four steps of the Fap1 glycosylation, catalyzing the transfer of GlcNAc, Glc, Glc, and GlcNAc residues to the protein backbone sequentially. The role of GalT2 and Gly in the Fap1 glycosylation is unknown. In the present study, we synthesized the fully modified Fap1 glycan in Escherichia coli by incorporating all six genes from the cluster. This study represents the first reconstitution of an exogenous stepwise O-glycosylation synthetic pathway in E. coli. In addition, we have determined that GalT2 mediates the fifth step of the Fap1 glycosylation by adding a rhamnose residue, and Gly mediates the final glycosylation step by transferring glucosyl residues. Furthermore, inactivation of each glycosyltransferase gene resulted in differentially impaired biofilms of S. parasanguinis, demonstrating the importance of Fap1 glycosylation in the biofilm formation. The Fap1 glycosylation system offers an excellent model to engineer glycans using different permutations of glycosyltransferases and to investigate biosynthetic pathways of SRRPs because SRRP genetic loci are highly conserved.
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Affiliation(s)
- Fan Zhu
- From the Departments of Pediatric Dentistry and.,Microbiology, University of Alabama at Birmingham, Schools of Dentistry and Medicine, Birmingham, Alabama 35244 and
| | - Hua Zhang
- From the Departments of Pediatric Dentistry and
| | - Tiandi Yang
- the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Stuart M Haslam
- the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Anne Dell
- the Department of Life Sciences, Imperial College London, London SW7 2AZ, United Kingdom
| | - Hui Wu
- From the Departments of Pediatric Dentistry and .,Microbiology, University of Alabama at Birmingham, Schools of Dentistry and Medicine, Birmingham, Alabama 35244 and
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9
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Lizcano A, Akula Suresh Babu R, Shenoy AT, Saville AM, Kumar N, D'Mello A, Hinojosa CA, Gilley RP, Segovia J, Mitchell TJ, Tettelin H, Orihuela CJ. Transcriptional organization of pneumococcal psrP-secY2A2 and impact of GtfA and GtfB deletion on PsrP-associated virulence properties. Microbes Infect 2017; 19:323-333. [PMID: 28408270 PMCID: PMC5581956 DOI: 10.1016/j.micinf.2017.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/10/2017] [Accepted: 04/03/2017] [Indexed: 01/08/2023]
Abstract
Pneumococcal serine-rich repeat protein (PsrP) is a glycoprotein that mediates Streptococcus pneumoniae attachment to lung cells and promotes biofilm formation. Herein, we investigated the transcriptional organization of psrP-secY2A2, the 37-kbp pathogenicity island encoding PsrP and its accessory genes. PCR amplification of cDNA and RNA-seq analysis found psrP-secY2A2 to be minimally composed of three operons: psrP-glyA, glyB, and glyC-asp5. Transcription of all three operons was greatest during biofilm growth and immunoblot analyses confirmed increased PsrP production by biofilm pneumococci. Using gas chromatography-mass spectrometry we identified monomeric N-acetylglucosamine as the primary glycoconjugate present on a recombinant intracellular version of PsrP, i.e. PsrP1-734. This finding was validated by immunoblot using lectins with known carbohydrate specificities. We subsequently deleted gtfA and gtfB, the GTFs thought to be responsible for addition of O-linked N-acetylglucosamine, and tested for PsrP and its associated virulence properties. These deletions negatively affected our ability to detect PsrP1-734 in bacterial whole cell lysates. Moreover, S. pneumoniae mutants lacking these genes pheno-copied the psrP mutant and were attenuated for: biofilm formation, adhesion to lung epithelial cells, and pneumonia in mice. Our studies identify the transcriptional organization of psrP-secY2A2 and show the indispensable role of GtfA and GtfB on PsrP-mediated pneumococcal virulence.
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Affiliation(s)
- Anel Lizcano
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Ramya Akula Suresh Babu
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Anukul T Shenoy
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Alison Maren Saville
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Nikhil Kumar
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Adonis D'Mello
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Cecilia A Hinojosa
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Ryan P Gilley
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Jesus Segovia
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Timothy J Mitchell
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, Scotland, UK; Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Carlos J Orihuela
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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10
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Streptococcus oralis Neuraminidase Modulates Adherence to Multiple Carbohydrates on Platelets. Infect Immun 2017; 85:IAI.00774-16. [PMID: 27993975 DOI: 10.1128/iai.00774-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 12/15/2016] [Indexed: 11/20/2022] Open
Abstract
Adherence to host surfaces is often mediated by bacterial binding to surface carbohydrates. Although it is widely appreciated that some bacterial species express glycosidases, previous studies have not considered whether bacteria bind to multiple carbohydrates within host glycans as they are modified by bacterial glycosidases. Streptococcus oralis is a leading cause of subacute infective endocarditis. Binding to platelets is a critical step in disease; however, the mechanisms utilized by S. oralis remain largely undefined. Studies revealed that S. oralis, like Streptococcus gordonii and Streptococcus sanguinis, binds platelets via terminal sialic acid. However, unlike those organisms, S. oralis produces a neuraminidase, NanA, which cleaves terminal sialic acid. Further studies revealed that following NanA-dependent removal of terminal sialic acid, S. oralis bound exposed β-1,4-linked galactose. Adherence to both these carbohydrates required Fap1, the S. oralis member of the serine-rich repeat protein (SRRP) family of adhesins. Mutation of a conserved residue required for sialic acid binding by other SRRPs significantly reduced platelet binding, supporting the hypothesis that Fap1 binds this carbohydrate. The mechanism by which Fap1 contributes to β-1,4-linked galactose binding remains to be defined; however, binding may occur via additional domains of unknown function within the nonrepeat region, one of which shares some similarity with a carbohydrate binding module. This study is the first demonstration that an SRRP is required to bind β-1,4-linked galactose and the first time that one of these adhesins has been shown to be required for binding of multiple glycan receptors.
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11
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Bleiziffer I, Eikmeier J, Pohlentz G, McAulay K, Xia G, Hussain M, Peschel A, Foster S, Peters G, Heilmann C. The Plasmin-Sensitive Protein Pls in Methicillin-Resistant Staphylococcus aureus (MRSA) Is a Glycoprotein. PLoS Pathog 2017; 13:e1006110. [PMID: 28081265 PMCID: PMC5230774 DOI: 10.1371/journal.ppat.1006110] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Accepted: 12/02/2016] [Indexed: 01/16/2023] Open
Abstract
Most bacterial glycoproteins identified to date are virulence factors of pathogenic bacteria, i.e. adhesins and invasins. However, the impact of protein glycosylation on the major human pathogen Staphylococcus aureus remains incompletely understood. To study protein glycosylation in staphylococci, we analyzed lysostaphin lysates of methicillin-resistant Staphylococcus aureus (MRSA) strains by SDS-PAGE and subsequent periodic acid-Schiff’s staining. We detected four (>300, ∼250, ∼165, and ∼120 kDa) and two (>300 and ∼175 kDa) glycosylated surface proteins with strain COL and strain 1061, respectively. The ∼250, ∼165, and ∼175 kDa proteins were identified as plasmin-sensitive protein (Pls) by mass spectrometry. Previously, Pls has been demonstrated to be a virulence factor in a mouse septic arthritis model. The pls gene is encoded by the staphylococcal cassette chromosome (SCC)mec type I in MRSA that also encodes the methicillin resistance-conferring mecA and further genes. In a search for glycosyltransferases, we identified two open reading frames encoded downstream of pls on the SCCmec element, which we termed gtfC and gtfD. Expression and deletion analysis revealed that both gtfC and gtfD mediate glycosylation of Pls. Additionally, the recently reported glycosyltransferases SdgA and SdgB are involved in Pls glycosylation. Glycosylation occurs at serine residues in the Pls SD-repeat region and modifying carbohydrates are N-acetylhexosaminyl residues. Functional characterization revealed that Pls can confer increased biofilm formation, which seems to involve two distinct mechanisms. The first mechanism depends on glycosylation of the SD-repeat region by GtfC/GtfD and probably also involves eDNA, while the second seems to be independent of glycosylation as well as eDNA and may involve the centrally located G5 domains. Other previously known Pls properties are not related to the sugar modifications. In conclusion, Pls is a glycoprotein and Pls glycosyl residues can stimulate biofilm formation. Thus, sugar modifications may represent promising new targets for novel therapeutic or prophylactic measures against life-threatening S. aureus infections. Staphylococcus aureus is a serious pathogen that causes life-threatening infections due to its ability to attach to surfaces, form biofilms, and persist inside the host. One of previously identified virulence factors in S. aureus pathogenesis is the plasmin-sensitive surface protein Pls. We here identified Pls as a posttranslationally modified glycoprotein and characterized the domain within Pls that becomes glycosylated as well as the modifying sugars. Moreover, we found that the glycosyltransferases GtfC and GtfD carry out the glycosylation reactions. In a search for a role for the modifying sugars, we found that Pls can stimulate biofilm formation apparently via two distinct mechanisms, one being dependent on glycosylation by GtfC and GtfD the other being independent of glycosylation as well as eDNA. Moreover, we found that none of the already known Pls functions is mediated by the sugar moieties. Thus, we conclude that GtfC/GtfD-glycosylated Pls may contribute to MRSA pathogenicity via stimulation of biofilm formation and may serve as future target to combat or prevent infections with this serious pathogen.
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Affiliation(s)
- Isabelle Bleiziffer
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
| | - Julian Eikmeier
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
| | | | - Kathryn McAulay
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Guoqing Xia
- Division of Infection, Immunity and Respiratory Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Muzaffar Hussain
- Institute of Medical Microbiology, University of Münster, Münster, Germany
| | - Andreas Peschel
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
- German Center for Infection Research (DZIF), partner site Tübingen, University of Tübingen, Tübingen, Germany
| | - Simon Foster
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Georg Peters
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
- Cluster of Excellence EXC 1003, Cells in Motion, University of Münster, Münster, Germany
| | - Christine Heilmann
- Institute of Medical Microbiology, University of Münster, Münster, Germany
- Interdisciplinary Center for Clinical Research (IZKF), University of Münster, Münster, Germany
- * E-mail:
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12
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Zhang H, Zhou M, Yang T, Haslam SM, Dell A, Wu H. New Helical Binding Domain Mediates a Glycosyltransferase Activity of a Bifunctional Protein. J Biol Chem 2016; 291:22106-22117. [PMID: 27539847 PMCID: PMC5063993 DOI: 10.1074/jbc.m116.731695] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Indexed: 11/08/2022] Open
Abstract
Serine-rich repeat glycoproteins (SRRPs) conserved in streptococci and staphylococci are important for bacterial colonization and pathogenesis. Fap1, a well studied SRRP is a major surface constituent of Streptococcus parasanguinis and is required for bacterial adhesion and biofilm formation. Biogenesis of Fap1 is a multistep process that involves both glycosylation and secretion. A series of glycosyltransferases catalyze sequential glycosylation of Fap1. We have identified a unique hybrid protein dGT1 (dual glycosyltransferase 1) that contains two distinct domains. N-terminal DUF1792 is a novel GT-D-type glycosyltransferase, transferring Glc residues to Glc-GlcNAc-modified Fap1. C-terminal dGT1 (CgT) is predicted to possess a typical GT-A-type glycosyltransferase, however, the activity remains unknown. In this study, we determine that CgT is a distinct glycosyltransferase, transferring GlcNAc residues to Glc-Glc-GlcNAc-modified Fap1. A 2.4-Å x-ray crystal structure reveals that CgT has a unique binding domain consisting of three α helices in addition to a typical GT-A-type glycosyltransferase domain. The helical domain is crucial for the oligomerization of CgT. Structural and biochemical studies revealed that the helix domain is required for the protein-protein interaction and crucial for the glycosyltransferase activity of CgT in vitro and in vivo. As the helix domain presents a novel structural fold, we conclude that CgT represents a new member of GT-A-type glycosyltransferases.
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Affiliation(s)
- Hua Zhang
- From the Departments of Pediatric Dentistry and Microbiology, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294 and
| | - Meixian Zhou
- From the Departments of Pediatric Dentistry and Microbiology, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294 and
| | - Tiandi Yang
- the Department of Life Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Stuart M Haslam
- the Department of Life Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Anne Dell
- the Department of Life Sciences, Imperial College London, London, SW7 2AZ, United Kingdom
| | - Hui Wu
- From the Departments of Pediatric Dentistry and Microbiology, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294 and
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13
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Li Y, Huang X, Li J, Zeng J, Zhu F, Fan W, Hu L. Both GtfA and GtfB are required for SraP glycosylation in Staphylococcus aureus. Curr Microbiol 2015; 69:121-6. [PMID: 24658735 DOI: 10.1007/s00284-014-0563-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 02/02/2014] [Indexed: 10/25/2022]
Abstract
Staphylococcus aureus has been shown to bind to human platelets through a variety of surface molecules, including serine-rich adhesin for platelets (SraP). The SraP mutant strain of S. aureus is significantly impaired in its ability to initiate infection compared with the wild strain. SraP is a cell wall-anchored, glycosylated protein. A previous study revealed that SecY2, Asp1, Asp2, Asp3, and SecA2 in the SraP operon were required for the efficient transport of glycosylated SraP from the cytoplasm to the bacterial cell surface. However, no glycosyltransferase (Gtf) was found to be involved in the glycosylation of SraP. In this study, SraP was found in all of the 55 clinical isolates of S. aureus using a real-time polymerase chain reaction assay. Sequence and phylogenetic analysis showed that GtfA and GtfB in the SraP operon were highly conserved in most of these clinical isolates. Conserved domains analysis revealed that both GtfA and GtfB contained a GT1_GtfA-like domain. Structural homology analysis inferred that they are both Gtfs. We then constructed an in vivo glycosylation system in Escherichia coli using SraP1–743 as the substrate and GtfA and GtfB as the Gtfs. Using this system, we found that GtfA and GtfB were the Gtfs that transferred the N-acetylglucosamine-containing oligosaccharides to the recombinant SraP1–743. Deletion of either one or both of the Gtfs abolished the glycosylation of SraP. In summary, GtfA and GtfB in the SraP operon are highly conserved in most clinical isolates of S. aureus, and both GtfA and GtfB are required for SraP glycosylation.
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14
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The sweet tooth of bacteria: common themes in bacterial glycoconjugates. Microbiol Mol Biol Rev 2015; 78:372-417. [PMID: 25184559 DOI: 10.1128/mmbr.00007-14] [Citation(s) in RCA: 106] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Humans have been increasingly recognized as being superorganisms, living in close contact with a microbiota on all their mucosal surfaces. However, most studies on the human microbiota have focused on gaining comprehensive insights into the composition of the microbiota under different health conditions (e.g., enterotypes), while there is also a need for detailed knowledge of the different molecules that mediate interactions with the host. Glycoconjugates are an interesting class of molecules for detailed studies, as they form a strain-specific barcode on the surface of bacteria, mediating specific interactions with the host. Strikingly, most glycoconjugates are synthesized by similar biosynthesis mechanisms. Bacteria can produce their major glycoconjugates by using a sequential or an en bloc mechanism, with both mechanistic options coexisting in many species for different macromolecules. In this review, these common themes are conceptualized and illustrated for all major classes of known bacterial glycoconjugates, with a special focus on the rather recently emergent field of glycosylated proteins. We describe the biosynthesis and importance of glycoconjugates in both pathogenic and beneficial bacteria and in both Gram-positive and -negative organisms. The focus lies on microorganisms important for human physiology. In addition, the potential for a better knowledge of bacterial glycoconjugates in the emerging field of glycoengineering and other perspectives is discussed.
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15
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Zhu F, Zhang H, Wu H. Glycosyltransferase-mediated Sweet Modification in Oral Streptococci. J Dent Res 2015; 94:659-65. [PMID: 25755271 DOI: 10.1177/0022034515574865] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Bacterial glycosyltransferases play important roles in bacterial fitness and virulence. Oral streptococci have evolved diverse strategies to survive and thrive in the carbohydrate-rich oral cavity. In this review, we discuss 2 important biological processes mediated by 2 distinct groups of glycosyltransferases in oral streptococci that are important for bacterial colonization and virulence. The first process is the glycosylation of highly conserved serine-rich repeat adhesins by a series of glycosyltransferases. Using Streptococcus parasanguinis as a model, we highlight new features of several glycosyltransferases that sequentially modify the serine-rich glycoprotein Fap1. Distinct features of a novel glycosyltransferase fold from a domain of unknown function 1792 are contrasted with common properties of canonical glycosyltransferases. The second biological process we cover is involved in building sticky glucan matrix to establish cariogenic biofilms by an important opportunistic pathogen Streptococcus mutans through the action of a family of 3 glucosyltransferases. We focus on discussing the structural feature of this family as a glycoside hydrolase family of enzymes. While the 2 processes are distinct, they all produce carbohydrate-coated biomolecules, which enable bacteria to stick better in the complex oral microbiome. Understanding the making of the sweet modification presents a unique opportunity to develop novel antiadhesion and antibiofilm strategies to fight infections by oral streptococci and beyond.
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Affiliation(s)
- F Zhu
- Departments of Microbiology and Pediatric Dentistry, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - H Zhang
- Departments of Microbiology and Pediatric Dentistry, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - H Wu
- Departments of Microbiology and Pediatric Dentistry, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
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16
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17
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A conserved domain is crucial for acceptor substrate binding in a family of glucosyltransferases. J Bacteriol 2014; 197:510-7. [PMID: 25404702 DOI: 10.1128/jb.02267-14] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Serine-rich repeat glycoproteins (SRRPs) are highly conserved in streptococci and staphylococci. Glycosylation of SRRPs is important for bacterial adhesion and pathogenesis. Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis among newborns. Srr2, an SRRP from S. agalactiae strain COH1, has been implicated in bacterial virulence. Four genes (gtfA, gtfB, gtfC, and gtfD) located downstream of srr2 share significant homology with genes involved in glycosylation of other SRRPs. We have shown previously that gtfA and gtfB encode two glycosyltransferases, GtfA and GtfB, that catalyze the transfer of GlcNAc residues to the Srr2 polypeptide. However, the function of other glycosyltransferases in glycosylation of Srr2 is unknown. In this study, we determined that GtfC catalyzed the direct transfer of glucosyl residues to Srr2-GlcNAc. The GtfC crystal structure was solved at 2.7 Å by molecular replacement. Structural analysis revealed a loop region at the N terminus as a putative acceptor substrate binding domain. Deletion of this domain rendered GtfC unable to bind to its substrate Srr2-GlcNAc, concurrently abolished the glycosyltransferase activity of GtfC, and also altered glycosylation of Srr2. Furthermore, deletion of the corresponding regions from GtfC homologs also abolished their substrate binding and enzymatic activity, indicating that this region is functionally conserved. In summary, we have determined that GtfC is important for the glycosylation of Srr2 and identified a conserved loop region that is crucial for acceptor substrate binding from GtfC homologs in streptococci. These findings shed new mechanistic insight into this family of glycosyltransferases.
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18
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Hasan I, Watanabe M, Ishizaki N, Sugita-Konishi Y, Kawakami Y, Suzuki J, Dogasaki C, Rajia S, Kawsar SMA, Koide Y, Kanaly RA, Sugawara S, Hosono M, Ogawa Y, Fujii Y, Iriko H, Hamako J, Matsui T, Ozeki Y. A galactose-binding lectin isolated from Aplysia kurodai (sea hare) eggs inhibits streptolysin-induced hemolysis. Molecules 2014; 19:13990-4003. [PMID: 25197935 PMCID: PMC6271371 DOI: 10.3390/molecules190913990] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 08/21/2014] [Accepted: 09/02/2014] [Indexed: 01/01/2023] Open
Abstract
A specific galactose-binding lectin was shown to inhibit the hemolytic effect of streptolysin O (SLO), an exotoxin produced by Streptococcus pyogenes. Commercially available lectins that recognize N-acetyllactosamine (ECA), T-antigen (PNA), and Tn-antigen (ABA) agglutinated rabbit erythrocytes, but had no effect on SLO-induced hemolysis. In contrast, SLO-induced hemolysis was inhibited by AKL, a lectin purified from sea hare (Aplysia kurodai) eggs that recognizes α-galactoside oligosaccharides. This inhibitory effect was blocked by the co-presence of d-galactose, which binds to AKL. A possible explanation for these findings is that cholesterol-enriched microdomains containing glycosphingolipids in the erythrocyte membrane become occupied by tightly stacked lectin molecules, blocking the interaction between cholesterol and SLO that would otherwise result in penetration of the membrane. Growth of S. pyogenes was inhibited by lectins from a marine invertebrate (AKL) and a mushroom (ABA), but was promoted by a plant lectin (ECA). Both these inhibitory and promoting effects were blocked by co-presence of galactose in the culture medium. Our findings demonstrate the importance of glycans and lectins in regulating mechanisms of toxicity, creation of pores in the target cell membrane, and bacterial growth.
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Affiliation(s)
- Imtiaj Hasan
- Laboratories of Glycobiology & Marine Biochemistry and Molecular Toxicology, Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan. Department of Biochemistry and Molecular Biology, Faculty of Science, University of Rajshahi, Rajshahi-6205, Bangladesh.
| | - Miharu Watanabe
- School of Life and Environmental Science, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - Naoto Ishizaki
- School of Life and Environmental Science, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - Yoshiko Sugita-Konishi
- School of Life and Environmental Science, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - Yasushi Kawakami
- School of Life and Environmental Science, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - Jun Suzuki
- School of Life and Environmental Science, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - Chikaku Dogasaki
- School of Life and Environmental Science, Azabu University, 1-17-71, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5201, Japan.
| | - Sultana Rajia
- Laboratories of Glycobiology & Marine Biochemistry and Molecular Toxicology, Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
| | - Sarkar M A Kawsar
- Department of Chemistry, Faculty of Sciences, University of Chittagong, Chittagong-4331, Bangladesh.
| | - Yasuhiro Koide
- Laboratories of Glycobiology & Marine Biochemistry and Molecular Toxicology, Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
| | - Robert A Kanaly
- Laboratories of Glycobiology & Marine Biochemistry and Molecular Toxicology, Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
| | - Shigeki Sugawara
- Division of Cell Recognition Study, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
| | - Masahiro Hosono
- Division of Cell Recognition Study, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
| | - Yukiko Ogawa
- Department of Pharmacy, Faculty of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan.
| | - Yuki Fujii
- Department of Pharmacy, Faculty of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan.
| | - Hideyuki Iriko
- Department of Parasitology, Graduate School of Health Sciences, Kobe University, 7-10-2, Tomogaoka, Suma-ku, Kobe 654-0142, Japan.
| | - Jiharu Hamako
- Department of Biology, School of Health Sciences, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
| | - Taei Matsui
- Department of Biology, School of Health Sciences, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
| | - Yasuhiro Ozeki
- Laboratories of Glycobiology & Marine Biochemistry and Molecular Toxicology, Department of Life and Environmental System Science, Graduate School of NanoBio Sciences, Yokohama City University, 22-2 Seto, Kanazawa-ku, Yokohama 236-0027, Japan.
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The highly conserved domain of unknown function 1792 has a distinct glycosyltransferase fold. Nat Commun 2014; 5:4339. [PMID: 25023666 PMCID: PMC4352575 DOI: 10.1038/ncomms5339] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 06/07/2014] [Indexed: 01/23/2023] Open
Abstract
More than 33,000 glycosyltransferases have been identified. Structural studies, however, have only revealed two distinct glycosyltransferase (GT) folds, GT-A and GT-B. Here we report a 1.34-Å resolution X-ray crystallographic structure of a previously uncharacterized 'domain of unknown function' 1792 (DUF1792) and show that the domain adopts a new fold and is required for glycosylation of a family of serine-rich repeat streptococcal adhesins. Biochemical studies reveal that the domain is a glucosyltransferase, and it catalyses the transfer of glucose to the branch point of the hexasaccharide O-linked to the serine-rich repeat of the bacterial adhesin, Fap1 of Streptococcus parasanguinis. DUF1792 homologues from both Gram-positive and Gram-negative bacteria also exhibit the activity. Thus, DUF1792 represents a new family of glycosyltransferases; therefore, we designate it as a GT-D glycosyltransferase fold. As the domain is highly conserved in bacteria and not found in eukaryotes, it can be explored as a new antibacterial target.
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20
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Takahashi K, Raska M, Stuchlova Horynova M, Hall SD, Poulsen K, Kilian M, Hiki Y, Yuzawa Y, Moldoveanu Z, Julian BA, Renfrow MB, Novak J. Enzymatic sialylation of IgA1 O-glycans: implications for studies of IgA nephropathy. PLoS One 2014; 9:e99026. [PMID: 24918438 PMCID: PMC4053367 DOI: 10.1371/journal.pone.0099026] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 04/23/2014] [Indexed: 11/18/2022] Open
Abstract
Patients with IgA nephropathy (IgAN) have elevated circulating levels of IgA1 with some O-glycans consisting of galactose (Gal)-deficient N-acetylgalactosamine (GalNAc) with or without N-acetylneuraminic acid (NeuAc). We have analyzed O-glycosylation heterogeneity of naturally asialo-IgA1 (Ale) myeloma protein that mimics Gal-deficient IgA1 (Gd-IgA1) of patients with IgAN, except that IgA1 O-glycans of IgAN patients are frequently sialylated. Specifically, serum IgA1 of healthy controls has more α2,3-sialylated O-glycans (NeuAc attached to Gal) than α2,6-sialylated O-glycans (NeuAc attached to GalNAc). As IgA1-producing cells from IgAN patients have an increased activity of α2,6-sialyltransferase (ST6GalNAc), we hypothesize that such activity may promote premature sialylation of GalNAc and, thus, production of Gd-IgA1, as sialylation of GalNAc prevents subsequent Gal attachment. Distribution of NeuAc in IgA1 O-glycans may play an important role in the pathogenesis of IgAN. To better understand biological functions of NeuAc in IgA1, we established protocols for enzymatic sialylation leading to α2,3- or α2,6-sialylation of IgA1 O-glycans. Sialylation of Gal-deficient asialo-IgA1 (Ale) myeloma protein by an ST6GalNAc enzyme generated sialylated IgA1 that mimics the Gal-deficient IgA1 glycoforms in patients with IgAN, characterized by α2,6-sialylated Gal-deficient GalNAc. In contrast, sialylation of the same myeloma protein by an α2,3-sialyltransferase yielded IgA1 typical for healthy controls, characterized by α2,3-sialylated Gal. The GalNAc-specific lectin from Helix aspersa (HAA) is used to measure levels of Gd-IgA1. We assessed HAA binding to IgA1 sialylated at Gal or GalNAc. As expected, α2,6-sialylation of IgA1 markedly decreased reactivity with HAA. Notably, α2,3-sialylation also decreased reactivity with HAA. Neuraminidase treatment recovered the original HAA reactivity in both instances. These results suggest that binding of a GalNAc-specific lectin is modulated by sialylation of GalNAc as well as Gal in the clustered IgA1 O-glycans. Thus, enzymatic sialylation offers a useful model to test the role of NeuAc in reactivities of the clustered O-glycans with lectins.
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Affiliation(s)
- Kazuo Takahashi
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Nephrology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Milan Raska
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Faculty of Medicine and Dentistry, Department of Immunology, Palacky University in Olomouc, Olomouc, Czech Republic
| | - Milada Stuchlova Horynova
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Faculty of Medicine and Dentistry, Department of Immunology, Palacky University in Olomouc, Olomouc, Czech Republic
| | - Stacy D. Hall
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Knud Poulsen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mogens Kilian
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Yoshiyuki Hiki
- Fujita Health University School of Health Sciences, Toyoake, Japan
| | - Yukio Yuzawa
- Department of Nephrology, Fujita Health University School of Medicine, Toyoake, Japan
| | - Zina Moldoveanu
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Bruce A. Julian
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Matthew B. Renfrow
- UAB Biomedical FT-ICR MS Laboratory, Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Jan Novak
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
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Chaze T, Guillot A, Valot B, Langella O, Chamot-Rooke J, Di Guilmi AM, Trieu-Cuot P, Dramsi S, Mistou MY. O-Glycosylation of the N-terminal region of the serine-rich adhesin Srr1 of Streptococcus agalactiae explored by mass spectrometry. Mol Cell Proteomics 2014; 13:2168-82. [PMID: 24797265 DOI: 10.1074/mcp.m114.038075] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Serine-rich (Srr) proteins exposed at the surface of Gram-positive bacteria are a family of adhesins that contribute to the virulence of pathogenic staphylococci and streptococci. Lectin-binding experiments have previously shown that Srr proteins are heavily glycosylated. We report here the first mass-spectrometry analysis of the glycosylation of Streptococcus agalactiae Srr1. After Srr1 enrichment and trypsin digestion, potential glycopeptides were identified in collision induced dissociation spectra using X! Tandem. The approach was then refined using higher energy collisional dissociation fragmentation which led to the simultaneous loss of sugar residues, production of diagnostic oxonium ions and backbone fragmentation for glycopeptides. This feature was exploited in a new open source software tool (SpectrumFinder) developed for this work. By combining these approaches, 27 glycopeptides corresponding to six different segments of the N-terminal region of Srr1 [93-639] were identified. Our data unambiguously indicate that the same protein residue can be modified with different glycan combinations including N-acetylhexosamine, hexose, and a novel modification that was identified as O-acetylated-N-acetylhexosamine. Lectin binding and monosaccharide composition analysis strongly suggested that HexNAc and Hex correspond to N-acetylglucosamine and glucose, respectively. The same protein segment can be modified with a variety of glycans generating a wide structural diversity of Srr1. Electron transfer dissociation was used to assign glycosylation sites leading to the unambiguous identification of six serines and one threonine residues. Analysis of purified Srr1 produced in mutant strains lacking accessory glycosyltransferase encoding genes demonstrates that O-GlcNAcylation is an initial step in Srr1 glycosylation that is likely required for subsequent decoration with Hex. In summary, our data obtained by a combination of fragmentation mass spectrometry techniques associated to a new software tool, demonstrate glycosylation heterogeneity of Srr1, characterize a new protein modification, and identify six glycosylation sites located in the N-terminal region of the protein.
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Affiliation(s)
- Thibault Chaze
- From the ‡INRA, MICALIS UMR-1319, 78352 Jouy-en-Josas cedex, France; §AgroParisTech, MICALIS UMR-1319, 78352 Jouy-en-Josas cedex, France; ¶¶Institut Pasteur, Unité de Spectrométrie de Masse Structurale et Protéomique, 28 rue du Dr Roux, 75015 Paris, France
| | - Alain Guillot
- ¶INRA, PAPPSO, MICALIS UMR-1319, 78352 Jouy en Josas cedex, France
| | - Benoît Valot
- ‖INRA, PAPPSO, Génétique végétale UMR-320, Ferme du Moulon, 91190 Gif sur Yvette, France
| | - Olivier Langella
- ‖INRA, PAPPSO, Génétique végétale UMR-320, Ferme du Moulon, 91190 Gif sur Yvette, France
| | - Julia Chamot-Rooke
- ¶¶Institut Pasteur, Unité de Spectrométrie de Masse Structurale et Protéomique, 28 rue du Dr Roux, 75015 Paris, France; ‖‖CNRS UMR 3528, Institut Pasteur, 28 rue du Dr Roux, 75015 Paris, France
| | - Anne-Marie Di Guilmi
- **CEA, Institut de Biologie Structurale Jean-Pierre Ebel, F-38027 Grenoble, France
| | - Patrick Trieu-Cuot
- ‡‡Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram+, 28, rue du Dr Roux, 75015 Paris, France; §§Centre National de la Recherche Scientifique, CNRS ERL3526, Paris, France
| | - Shaynoor Dramsi
- ‡‡Institut Pasteur, Unité de Biologie des Bactéries Pathogènes à Gram+, 28, rue du Dr Roux, 75015 Paris, France; §§Centre National de la Recherche Scientifique, CNRS ERL3526, Paris, France
| | - Michel-Yves Mistou
- From the ‡INRA, MICALIS UMR-1319, 78352 Jouy-en-Josas cedex, France; §AgroParisTech, MICALIS UMR-1319, 78352 Jouy-en-Josas cedex, France;
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22
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Yamamoto ML, Maier I, Dang AT, Berry D, Liu J, Ruegger PM, Yang JI, Soto PA, Presley LL, Reliene R, Westbrook AM, Wei B, Loy A, Chang C, Braun J, Borneman J, Schiestl RH. Intestinal bacteria modify lymphoma incidence and latency by affecting systemic inflammatory state, oxidative stress, and leukocyte genotoxicity. Cancer Res 2014; 73:4222-32. [PMID: 23860718 DOI: 10.1158/0008-5472.can-13-0022] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Ataxia-telangiectasia is a genetic disorder associated with high incidence of B-cell lymphoma. Using an ataxia-telangiectasia mouse model, we compared lymphoma incidence in several isogenic mouse colonies harboring different bacterial communities, finding that intestinal microbiota are a major contributor to disease penetrance and latency, lifespan, molecular oxidative stress, and systemic leukocyte genotoxicity. High-throughput sequence analysis of rRNA genes identified mucosa-associated bacterial phylotypes that were colony-specific. Lactobacillus johnsonii, which was deficient in the more cancer-prone mouse colony, was causally tested for its capacity to confer reduced genotoxicity when restored by short-term oral transfer. This intervention decreased systemic genotoxicity, a response associated with reduced basal leukocytes and the cytokine-mediated inflammatory state, and mechanistically linked to the host cell biology of systemic genotoxicity. Our results suggest that intestinal microbiota are a potentially modifiable trait for translational intervention in individuals at risk for B-cell lymphoma, or for other diseases that are driven by genotoxicity or the molecular response to oxidative stress.
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Affiliation(s)
- Mitsuko L Yamamoto
- Department of Pathology and Lab Medicine, David Geffen School of Medicine, University of California, California, USA
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23
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Misra S, Sharma V, Srivastava AK. Bacterial Polysaccharides: An Overview. POLYSACCHARIDES 2014. [DOI: 10.1007/978-3-319-03751-6_68-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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24
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Garnett JA, Matthews S. Interactions in bacterial biofilm development: a structural perspective. Curr Protein Pept Sci 2013; 13:739-55. [PMID: 23305361 PMCID: PMC3601411 DOI: 10.2174/138920312804871166] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 07/16/2012] [Accepted: 08/03/2012] [Indexed: 11/24/2022]
Abstract
A community-based life style is the normal mode of growth and survival for many bacterial species. These cellular accretions or biofilms are initiated upon recognition of solid phases by cell surface exposed adhesive moieties. Further cell-cell interactions, cell signalling and bacterial replication leads to the establishment of dense populations encapsulated in a mainly self-produced extracellular matrix; this comprises a complex mixture of macromolecules. These fascinating architectures protect the inhabitants from radiation damage, dehydration, pH fluctuations and antimicrobial compounds. As such they can cause bacterial persistence in disease and problems in industrial applications. In this review we discuss the current understandings of these initial biofilm-forming processes based on structural data. We also briefly describe latter biofilm maturation and dispersal events, which although lack high-resolution insights, are the present focus for many structural biologists working in this field. Finally we give an overview of modern techniques aimed at preventing and disrupting problem biofilms.
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Affiliation(s)
- James A Garnett
- Centre for Structural Biology, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, UK
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25
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Iwashkiw JA, Vozza NF, Kinsella RL, Feldman MF. Pour some sugar on it: the expanding world of bacterial proteinO-linked glycosylation. Mol Microbiol 2013; 89:14-28. [DOI: 10.1111/mmi.12265] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/15/2013] [Indexed: 11/26/2022]
Affiliation(s)
- Jeremy A. Iwashkiw
- Alberta Glycomics Centre; Department of Biological Sciences; University of Alberta; CW405 Biological Sciences Building; Edmonton; Alberta; Canada; T6G 2E9
| | - Nicolas F. Vozza
- Alberta Glycomics Centre; Department of Biological Sciences; University of Alberta; CW405 Biological Sciences Building; Edmonton; Alberta; Canada; T6G 2E9
| | - Rachel L. Kinsella
- Alberta Glycomics Centre; Department of Biological Sciences; University of Alberta; CW405 Biological Sciences Building; Edmonton; Alberta; Canada; T6G 2E9
| | - Mario F. Feldman
- Alberta Glycomics Centre; Department of Biological Sciences; University of Alberta; CW405 Biological Sciences Building; Edmonton; Alberta; Canada; T6G 2E9
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26
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Gap2 promotes the formation of a stable protein complex required for mature Fap1 biogenesis. J Bacteriol 2013; 195:2166-76. [PMID: 23475979 DOI: 10.1128/jb.02255-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Serine-rich repeat glycoproteins (SRRPs) are important bacterial adhesins conserved in streptococci and staphylococci. Fap1, a SRRP identified in Streptococcus parasanguinis, is the major constituent of bacterial fimbriae and is required for adhesion and biofilm formation. An 11-gene cluster is required for Fap1 glycosylation and secretion; however, the exact mechanism of Fap1 biogenesis remains a mystery. Two glycosylation-associated proteins within this cluster--Gap1 and Gap3--function together in Fap1 biogenesis. Here we report the role of the third glycosylation-associated protein, Gap2. A gap2 mutant exhibited the same phenotype as the gap1 and gap3 mutants in terms of Fap1 biogenesis, fimbrial assembly, and bacterial adhesion, suggesting that the three proteins interact. Indeed, all three proteins interacted with each other independently and together to form a stable protein complex. Mechanistically, Gap2 protected Gap3 from degradation by ClpP protease, and Gap2 required the presence of Gap1 for expression at the wild-type level. Gap2 augmented the function of Gap1 in stabilizing Gap3; this function was conserved in Gap homologs from Streptococcus agalactiae. Our studies demonstrate that the three Gap proteins work in concert in Fap1 biogenesis and reveal a new function of Gap2. This insight will help us elucidate the molecular mechanism of SRRP biogenesis in this bacterium and in pathogenic species.
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27
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Abstract
The conserved general secretion (Sec) pathway carries out most protein export in bacteria and is powered by the essential ATPase SecA. Interestingly, mycobacteria and some Gram-positive bacteria possess two SecA proteins: SecA1 and SecA2. In these species, SecA1 is responsible for exporting most proteins, whereas SecA2 exports only a subset of substrates and is implicated in virulence. However, despite the impressive body of knowledge about the canonical SecA1, less is known concerning SecA2 function. Here, we review our current understanding of the different types of SecA2 systems and outline future directions for their study.
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Affiliation(s)
- Meghan E Feltcher
- Department of Microbiology and Immunology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-27290, USA
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28
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Lizcano A, Sanchez CJ, Orihuela CJ. A role for glycosylated serine-rich repeat proteins in gram-positive bacterial pathogenesis. Mol Oral Microbiol 2012; 27:257-69. [PMID: 22759311 DOI: 10.1111/j.2041-1014.2012.00653.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Bacterial attachment to host surfaces is a pivotal event in the biological and infectious processes of both commensal and pathogenic bacteria, respectively. Serine-rich repeat proteins (SRRPs) are a family of adhesins in Gram-positive bacteria that mediate attachment to a variety of host and bacterial surfaces. As such, they contribute towards a wide-range of diseases including sub-acute bacterial endocarditis, community-acquired pneumonia, and meningitis. SRRPs are unique in that they are glycosylated, require a non-canonical Sec-translocase for transport, and are largely composed of a domain containing hundreds of alternating serine residues. These serine-rich repeats are thought to extend a unique non-repeat (NR) domain outward away from the bacterial surface to mediate adhesion. So far, NR domains have been determined to bind to sialic acid moieties, keratins, or other NR domains of a similar SRRP. This review summarizes how this important family of bacterial adhesins mediates bacterial attachment to host and bacterial cells, contributes to disease pathogenesis, and might be targeted for pharmacological intervention or used as novel protective vaccine antigens. This review also highlights recent structural findings on the NR domains of these proteins.
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Affiliation(s)
- A Lizcano
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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29
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Sadjadi SA, Ali H. Streptococcus parasanguis peritonitis: report of a case and review of the literature. Perit Dial Int 2012; 31:603-4. [PMID: 21976479 DOI: 10.3747/pdi.2011.00011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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30
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Zhou M, Zhu F, Li Y, Zhang H, Wu H. Gap1 functions as a molecular chaperone to stabilize its interactive partner Gap3 during biogenesis of serine-rich repeat bacterial adhesin. Mol Microbiol 2012; 83:866-78. [PMID: 22251284 DOI: 10.1111/j.1365-2958.2012.07970.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Serine-rich repeat glycoproteins (SRRPs) are important bacterial adhesins that are conserved in streptococci and staphylococci. Fimbriae-associated protein (Fap1) from Streptococcus parasanguinis, was the first SRRP identified; it plays an important role in bacterial biofilm formation. A gene cluster encoding glycosyltransferases and accessory secretion components is required for Fap1 biogenesis. Two glycosylation-associated proteins, Gap1 and Gap3 within the cluster, interact with each other and function in concert in Fap1 biogenesis. Here we report the new molecular events underlying contribution of the interaction to Fap1 biogenesis. The Gap1-deficient mutant rendered Gap3 unstable and degraded in vitro and in vivo. Inactivation of a gene encoding protease ClpP reversed the phenotype of the gap1 mutant, suggesting that ClpP is responsible for degradation of Gap3. Molecular chaperone GroEL was co-purified with Gap3 only when Gap1 was absent and also reacted with Gap1 monoclonal antibody, suggesting that Gap1 functions as a specific chaperone for Gap3. The N-terminal interacting domains of Gap1 mediated the Gap3 stability and Fap1 biogenesis. Gap1 homologues from Streptococcus agalactiae and Staphylococcus aureus also interacted with and stabilized corresponding Gap3 homologues, suggesting that the chaperone activity of the Gap1 homologues is common in biogenesis of SRRPs.
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Affiliation(s)
- Meixian Zhou
- Departments of Pediatric Dentistry and Microbiology, University of Alabama at Birmingham, Schools of Dentistry and Medicine, Birmingham, AL 35294, USA
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31
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Garnett JA, Simpson PJ, Taylor J, Benjamin SV, Tagliaferri C, Cota E, Chen YYM, Wu H, Matthews S. Structural insight into the role of Streptococcus parasanguinis Fap1 within oral biofilm formation. Biochem Biophys Res Commun 2012; 417:421-6. [PMID: 22166217 PMCID: PMC3518267 DOI: 10.1016/j.bbrc.2011.11.131] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 11/28/2011] [Indexed: 12/22/2022]
Abstract
The fimbriae-associated protein 1 (Fap1) is a major adhesin of Streptococcus parasanguinis, a primary colonizer of the oral cavity that plays an important role in the formation of dental plaque. Fap1 is an extracellular adhesive surface fibre belonging to the serine-rich repeat protein (SRRP) family, which plays a central role in the pathogenesis of streptococci and staphylococci. The N-terminal adhesive region of Fap1 (Fap1-NR) is composed of two domains (Fap1-NR(α) and Fap1-NR(β)) and is projected away from the bacterial surface via the extensive serine-rich repeat region, for adhesion to the salivary pellicle. The adhesive properties of Fap1 are modulated through a pH switch in which a reduction in pH results in a rearrangement between the Fap1-NR(α) and Fap1-NR(β) domains, which assists in the survival of S. parasanguinis in acidic environments. We have solved the structure of Fap1-NR(α) at pH 5.0 at 3.0Ǻ resolution and reveal how subtle rearrangements of the 3-helix bundle combined with a change in electrostatic potential mediates 'opening' and activation of the adhesive region. Further, we show that pH-dependent changes are critical for biofilm formation and present an atomic model for the inter-Fap1-NR interactions which have been assigned an important role in the biofilm formation.
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Affiliation(s)
- James A. Garnett
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Peter J. Simpson
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Jonathan Taylor
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Stefi V. Benjamin
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Camille Tagliaferri
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Ernesto Cota
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - Yi-Ywan M. Chen
- Department of Microbiology & Immunology, and Research Center for Pathogenic Bacteria, Chang Gung University, Tao-Yuan, Taiwan
| | - Hui Wu
- Department of Pediatric Dentistry, University of Alabama at Birmingham, School of Dentistry, Birmingham, AL 35294
| | - Stephen Matthews
- Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, UK
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Canonical SecA associates with an accessory secretory protein complex involved in biogenesis of a streptococcal serine-rich repeat glycoprotein. J Bacteriol 2011; 193:6560-6. [PMID: 21965576 DOI: 10.1128/jb.05668-11] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fap1, a serine-rich repeat glycoprotein (SRRP), is required for bacterial biofilm formation of Streptococcus parasanguinis. Fap1-like SRRPs are found in many gram-positive bacteria and have been implicated in bacterial fitness and virulence. A conserved five-gene cluster, secY2-gap1-gap2-gap3-secA2, located immediately downstream of fap1, is required for Fap1 biogenesis. secA2, gap1, and gap3 encode three putative accessory Sec proteins. SecA2 mediates export of mature Fap1, and Gap1 and Gap3 are required for Fap1 biogenesis. Interestingly, gap1 and gap3 mutants exhibited the same phenotype as a secA2 mutant, implying that Gap1 and Gap3 may interact with SecA2 to mediate Fap1 biogenesis. Glutathione S-transferase pulldown experiments revealed a direct interaction between SecA2, Gap1, and Gap3 in vitro. Coimmunoprecipitation analysis demonstrated the formation of a SecA2-Gap1-Gap3 complex. Homologues of SecA2, Gap1, and Gap3 are conserved in many streptococci and staphylococci. The corresponding homologues from Streptococcus agalactiae also interacted with each other and formed a protein complex. Furthermore, the Gap1 homologues from S. agalactiae and Streptococcus sanguinis rescued the Fap1 defect in the Gap1 mutant, indicating the functional conservation of the accessory Sec complex. Importantly, canonical SecA interacted with the accessory Sec protein complex, suggesting that the biogenesis of SRRPs mediated by the accessory Sec system is linked to the canonical Sec system.
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33
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Wu R, Wu H. A molecular chaperone mediates a two-protein enzyme complex and glycosylation of serine-rich streptococcal adhesins. J Biol Chem 2011; 286:34923-31. [PMID: 21862581 DOI: 10.1074/jbc.m111.239350] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Serine-rich repeat glycoproteins identified from streptococci and staphylococci are important for bacterial adhesion and biofilm formation. Two putative glycosyltransferases, Gtf1 and Gtf2, from Streptococcus parasanguinis form a two-protein enzyme complex that is required for glycosylation of a serine-rich repeat adhesin, Fap1. Gtf1 is a glycosyltransferase; however, the function of Gtf2 is unknown. Here, we demonstrate that Gtf2 enhances the enzymatic activity of Gtf1 by its chaperone-like property. Gtf2 interacted with Gtf1, mediated the subcellular localization of Gtf1, and stabilized Gtf1. Deletion of invariable amino acid residues in a conserved domain of unknown function (DUF1975) at the N terminus of Gtf2 had a greater impact on Fap1 glycosylation than deletion of the C-terminal non-DUF1975 residues. The DUF1975 deletions concurrently reduced the interaction between Gtf1 and Gtf2, altered the subcellular localization of Gtf1, and destabilized Gtf1, suggesting that DUF1975 is crucial for the chaperone activity of Gtf2. Homologous GtfA and GtfB from Streptococcus agalactiae rescued the glycosylation defect in the gtf1gtf2 mutant; like Gtf2, GtfB also possesses chaperone-like activity. Taken together, our studies suggest that Gtf2 and its homologs possess the conserved molecular chaperone activity that mediates protein glycosylation of bacterial adhesins.
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Affiliation(s)
- Ren Wu
- Department of Pediatric Dentistry and Microbiology, Schools of Dentistry and Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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34
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New cell surface protein involved in biofilm formation by Streptococcus parasanguinis. Infect Immun 2011; 79:3239-48. [PMID: 21576336 DOI: 10.1128/iai.00029-11] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Dental biofilm formation is critical for maintaining the healthy microbial ecology of the oral cavity. Streptococci are predominant bacterial species in the oral cavity and play important roles in the initiation of plaque formation. In this study, we identified a new cell surface protein, BapA1, from Streptococcus parasanguinis FW213 and determined that BapA1 is critical for biofilm formation. Sequence analysis revealed that BapA1 possesses a typical cell wall-sorting signal for cell surface-anchored proteins from Gram-positive bacteria. No functional orthologue was reported in other streptococci. BapA1 possesses nine putative pilin isopeptide linker domains which are crucial for pilus assembly in a number of Gram-positive bacteria. Deletion of the 3' portion of bapA1 generated a mutant that lacks surface-anchored BapA1 and abolishes formation of short fibrils on the cell surface. The mutant failed to form biofilms and exhibited reduced adherence to an in vitro tooth model. The BapA1 deficiency also inhibited bacterial autoaggregation. The N-terminal muramidase-released-protein-like domain mediated BapA1-BapA1 interactions, suggesting that BapA1-mediated cell-cell interactions are important for bacterial autoaggregation and biofilm formation. Furthermore, the BapA1-mediated bacterial adhesion and biofilm formation are independent of a fimbria-associated serine-rich repeat adhesin, Fap1, demonstrating that BapA1 is a new streptococcal adhesin.
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Garnett JA, Ramboarina S, Lee WC, Tagliaferri C, Wu W, Matthews S. Crystallization and initial crystallographic analysis of the Streptococcus parasanguinis FW213 Fap1-NRα adhesive domain at pH 5.0. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:274-6. [PMID: 21301104 PMCID: PMC3034626 DOI: 10.1107/s1744309110052772] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2010] [Accepted: 12/15/2010] [Indexed: 11/10/2022]
Abstract
The adhesin fimbriae-associated protein 1 (Fap1) is a surface protein of Streptococcus parasanguinis FW213 and plays a major role in the formation of dental plaque in humans. Increased adherence is highly correlated to a reduction in pH and acid activation has been mapped to a subdomain: Fap1-NR(α). Here, Fap1-NR(α) has been crystallized at pH 5.0 and diffraction data have been collected to 3.0 Å resolution. The crystals belonged to space group P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 122.0, c = 117.8 Å. It was not possible to conclusively determine the number of molecules in the asymmetric unit and heavy-atom derivatives are now being prepared.
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Affiliation(s)
- James A. Garnett
- Centre for Structural Biology, Division of Molecular Biosciences, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, England
| | - Stéphanie Ramboarina
- Centre for Structural Biology, Division of Molecular Biosciences, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, England
| | - Wei-chao Lee
- Centre for Structural Biology, Division of Molecular Biosciences, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, England
| | - Camille Tagliaferri
- Centre for Structural Biology, Division of Molecular Biosciences, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, England
| | - Wilfred Wu
- Centre for Structural Biology, Division of Molecular Biosciences, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, England
| | - Stephen Matthews
- Centre for Structural Biology, Division of Molecular Biosciences, Department of Life Sciences, Imperial College London, South Kensington, London SW7 2AZ, England
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36
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King NP, Beatson SA, Totsika M, Ulett GC, Alm RA, Manning PA, Schembri MA. UafB is a serine-rich repeat adhesin of Staphylococcus saprophyticus that mediates binding to fibronectin, fibrinogen and human uroepithelial cells. MICROBIOLOGY-SGM 2011; 157:1161-1175. [PMID: 21252279 DOI: 10.1099/mic.0.047639-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Staphylococcus saprophyticus is an important cause of urinary tract infection (UTI), particularly among young women, and is second only to uropathogenic Escherichia coli as the most frequent cause of UTI. The molecular mechanisms of urinary tract colonization by S. saprophyticus remain poorly understood. We have identified a novel 6.84 kb plasmid-located adhesin-encoding gene in S. saprophyticus strain MS1146 which we have termed uro-adherence factor B (uafB). UafB is a glycosylated serine-rich repeat protein that is expressed on the surface of S. saprophyticus MS1146. UafB also functions as a major cell surface hydrophobicity factor. To characterize the role of UafB we generated an isogenic uafB mutant in S. saprophyticus MS1146 by interruption with a group II intron. The uafB mutant had a significantly reduced ability to bind to fibronectin and fibrinogen. Furthermore, we show that a recombinant protein containing the putative binding domain of UafB binds specifically to fibronectin and fibrinogen. UafB was not involved in adhesion in a mouse model of UTI; however, we observed a striking UafB-mediated adhesion phenotype to human uroepithelial cells. We have also identified genes homologous to uafB in other staphylococci which, like uafB, appear to be located on transposable elements. Thus, our data indicate that UafB is a novel adhesin of S. saprophyticus that contributes to cell surface hydrophobicity, mediates adhesion to fibronectin and fibrinogen, and exhibits tropism for human uroepithelial cells.
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Affiliation(s)
- Nathan P King
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Makrina Totsika
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Glen C Ulett
- School of Medical Sciences, Centre for Medicine and Oral Health, Griffith University Gold Coast Campus, QLD 4222, Australia
| | | | | | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
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Purification and characterization of an active N-acetylglucosaminyltransferase enzyme complex from Streptococci. Appl Environ Microbiol 2010; 76:7966-71. [PMID: 20971868 DOI: 10.1128/aem.01434-10] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A new family of bacterial serine-rich repeat glycoproteins can function as adhesins required for biofilm formation and pathogenesis in streptococci and staphylococci. Biogenesis of these proteins depends on a gene cluster coding for glycosyltransferases and accessory secretion proteins. Previous studies show that Fap1, a member of this family from Streptococcus parasanguinis, can be glycosylated by a protein glycosylation complex in a recombinant heterogeneous host. Here we report a tandem affinity purification (TAP) approach used to isolate and study protein complexes from native streptococci. This method demonstrated that a putative glycosyltransferase (Gtf2), which is essential for Fap1 glycosylation, readily copurified with another glycosyltransferase (Gtf1) from native S. parasanguinis. This result and the similar isolation of a homologous two-protein complex from Streptococcus pneumoniae indicate the biological relevance of the complexes to the glycosylation in streptococci. Furthermore, novel N-acetylglucosaminyltransferase activity was discovered for the complexes. Optimal activity required heterodimer formation and appears to represent a novel type of glycosylation.
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38
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Ramboarina S, Garnett JA, Zhou M, Li Y, Peng Z, Taylor JD, Lee WC, Bodey A, Murray JW, Alguel Y, Bergeron J, Bardiaux B, Sawyer E, Isaacson R, Tagliaferri C, Cota E, Nilges M, Simpson P, Ruiz T, Wu H, Matthews S. Structural insights into serine-rich fimbriae from Gram-positive bacteria. J Biol Chem 2010; 285:32446-57. [PMID: 20584910 PMCID: PMC2952246 DOI: 10.1074/jbc.m110.128165] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2010] [Revised: 06/25/2010] [Indexed: 11/06/2022] Open
Abstract
The serine-rich repeat family of fimbriae play important roles in the pathogenesis of streptococci and staphylococci. Despite recent attention, their finer structural details and precise adhesion mechanisms have yet to be determined. Fap1 (Fimbriae-associated protein 1) is the major structural subunit of serine-rich repeat fimbriae from Streptococcus parasanguinis and plays an essential role in fimbrial biogenesis, adhesion, and the early stages of dental plaque formation. Combining multidisciplinary, high resolution structural studies with biological assays, we provide new structural insight into adhesion by Fap1. We propose a model in which the serine-rich repeats of Fap1 subunits form an extended structure that projects the N-terminal globular domains away from the bacterial surface for adhesion to the salivary pellicle. We also uncover a novel pH-dependent conformational change that modulates adhesion and likely plays a role in survival in acidic environments.
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Affiliation(s)
- Stéphanie Ramboarina
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - James A. Garnett
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Meixian Zhou
- the Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, Alabama 35294-0007
| | - Yuebin Li
- the Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, Alabama 35294-0007
| | - Zhixiang Peng
- the Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, Alabama 35294-0007
| | - Jonathan D. Taylor
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Wei-chao Lee
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Andrew Bodey
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - James W. Murray
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Yilmaz Alguel
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Julien Bergeron
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
- the Department of Infectious Diseases, King's College London School of Medicine, London SE1 9RT, United Kingdom
| | - Benjamin Bardiaux
- the Structural Biology Unit, Leibniz Institute for Molecular Pharmacology, FMP Robert-Rossle Strasse 10, 13125 Berlin, Germany
| | - Elizabeth Sawyer
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Rivka Isaacson
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Camille Tagliaferri
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Ernesto Cota
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Michael Nilges
- the Institut Pasteur Unité de Bioinformatique Structurale, 25-28 Rue du Dr Roux, F-75724 Paris Cedex 15, France, and
| | - Peter Simpson
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
| | - Teresa Ruiz
- the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405
| | - Hui Wu
- the Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, Alabama 35294-0007
| | - Stephen Matthews
- From the Department of Biological Sciences, Centre for Structural Biology, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom
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Lefèvre CT, Santini CL, Bernadac A, Zhang WJ, Li Y, Wu LF. Calcium ion-mediated assembly and function of glycosylated flagellar sheath of marine magnetotactic bacterium. Mol Microbiol 2010; 78:1304-12. [DOI: 10.1111/j.1365-2958.2010.07404.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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40
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Takahashi K, Wall SB, Suzuki H, Smith AD, Hall S, Poulsen K, Kilian M, Mobley JA, Julian BA, Mestecky J, Novak J, Renfrow MB. Clustered O-glycans of IgA1: defining macro- and microheterogeneity by use of electron capture/transfer dissociation. Mol Cell Proteomics 2010; 9:2545-57. [PMID: 20823119 DOI: 10.1074/mcp.m110.001834] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the world. Aberrantly glycosylated IgA1, with galactose (Gal)-deficient hinge region (HR) O-glycans, plays a pivotal role in the pathogenesis of the disease. It is not known whether the glycosylation defect occurs randomly or preferentially at specific sites. We have described the utility of activated ion-electron capture dissociation (AI-ECD) mass spectrometric analysis of IgA1 O-glycosylation. However, locating and characterizing the entire range of O-glycan attachment sites are analytically challenging due to the clustered serine and threonine residues in the HR of IgA1 heavy chain. To address this problem, we analyzed all glycoforms of the HR glycopeptides of a Gal-deficient IgA1 myeloma protein, mimicking the aberrant IgA1 in patients with IgAN, by use of a combination of IgA-specific proteases + trypsin and AI-ECD Fourier transform ion cyclotron resonance (FT-ICR) tandem mass spectrometry (MS/MS). The IgA-specific proteases provided a variety of IgA1 HR fragments that allowed unambiguous localization of all O-glycosylation sites in the six most abundant glycoforms, including the sites deficient in Gal. Additionally, this protocol was adapted for on-line liquid chromatography (LC)-AI-ECD MS/MS and LC-electron transfer dissociation MS/MS analysis. Our results thus represent a new clinically relevant approach that requires ECD/electron transfer dissociation-type fragmentation to define the molecular events leading to pathogenesis of a chronic kidney disease. Furthermore, this work offers generally applicable principles for the analysis of clustered sites of O-glycosylation.
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Affiliation(s)
- Kazuo Takahashi
- Biomedical FT-ICR MS Laboratory, Department of Biochemistry and Molecular Genetics, University of Alabama, Birmingham, Alabama 35294-0005, USA
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41
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Sanchez CJ, Shivshankar P, Stol K, Trakhtenbroit S, Sullam PM, Sauer K, Hermans PWM, Orihuela CJ. The pneumococcal serine-rich repeat protein is an intra-species bacterial adhesin that promotes bacterial aggregation in vivo and in biofilms. PLoS Pathog 2010; 6:e1001044. [PMID: 20714350 PMCID: PMC2920850 DOI: 10.1371/journal.ppat.1001044] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 07/14/2010] [Indexed: 12/16/2022] Open
Abstract
The Pneumococcal serine-rich repeat protein (PsrP) is a pathogenicity island encoded adhesin that has been positively correlated with the ability of Streptococcus pneumoniae to cause invasive disease. Previous studies have shown that PsrP mediates bacterial attachment to Keratin 10 (K10) on the surface of lung cells through amino acids 273–341 located in the Basic Region (BR) domain. In this study we determined that the BR domain of PsrP also mediates an intra-species interaction that promotes the formation of large bacterial aggregates in the nasopharynx and lungs of infected mice as well as in continuous flow-through models of mature biofilms. Using numerous methods, including complementation of mutants with BR domain deficient constructs, fluorescent microscopy with Cy3-labeled recombinant (r)BR, Far Western blotting of bacterial lysates, co-immunoprecipitation with rBR, and growth of biofilms in the presence of antibodies and competitive peptides, we determined that the BR domain, in particular amino acids 122–166 of PsrP, promoted bacterial aggregation and that antibodies against the BR domain were neutralizing. Using similar methodologies, we also determined that SraP and GspB, the Serine-rich repeat proteins (SRRPs) of Staphylococcus aureus and Streptococcus gordonii, respectively, also promoted bacterial aggregation and that their Non-repeat domains bound to their respective SRRPs. This is the first report to show the presence of biofilm-like structures in the lungs of animals infected with S. pneumoniae and show that SRRPs have dual roles as host and bacterial adhesins. These studies suggest that recombinant Non-repeat domains of SRRPs (i.e. BR for S. pneumoniae) may be useful as vaccine antigens to protect against Gram-positive bacteria that cause infection. Serine-rich repeat proteins (SRRPs) are a family of surface-expressed proteins found in numerous Gram-positive pathogens, including Staphylococcus aureus, Streptococcus pneumoniae, Group B streptococci, and the oral streptococci that cause infective endocarditis. For all of these bacteria, SRRPs have been demonstrated to play pivotal roles in adhesion to tissues and the development of invasive disease. It is now known that biofilm formation is an important step for bacterial pathogenesis. Bacteria in biofilms have been shown to have differences in metabolism, gene expression, and protein production that contribute to enhanced surface adhesion and the persistence of an infection. Herein we describe a novel role for PsrP, the S. pneumoniae SRRP, as an intra-species bacterial adhesin that promotes bacterial aggregation in the lungs of infected mice during pneumonia. In vitro we show that the Basic Region domain of PsrP promotes self-interactions that result in denser biofilms, greater biofilm biomass, and altered architectures of surface grown cultures; these interactions could be neutralized by antibodies to PsrP that are protective against pneumococcal infection. We also demonstrate that the SRRPs of S. aureus and Streptococcus gordonii also function as intra-species bacterial adhesins. Therefore we conclude that SRRPs have dual roles as host-cell and intra-species bacterial adhesins.
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MESH Headings
- Adhesins, Bacterial/chemistry
- Adhesins, Bacterial/genetics
- Adhesins, Bacterial/metabolism
- Amino Acid Motifs
- Animals
- Bacterial Adhesion/physiology
- Biofilms/growth & development
- Blotting, Western
- Female
- Immunoprecipitation
- Mice
- Mice, Inbred BALB C
- Microscopy, Confocal
- Microscopy, Electron, Scanning
- Microscopy, Fluorescence
- Protein Structure, Tertiary/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Streptococcus pneumoniae/metabolism
- Streptococcus pneumoniae/pathogenicity
- Streptococcus pneumoniae/physiology
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Affiliation(s)
- Carlos J. Sanchez
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
| | - Pooja Shivshankar
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
| | - Kim Stol
- Laboratory of Pediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Samuel Trakhtenbroit
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
| | - Paul M. Sullam
- Division of Infectious Diseases, San Francisco VA Medical Center and the University of California, San Francisco, California, United States of America
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, United States of America
| | - Peter W. M. Hermans
- Laboratory of Pediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Carlos J. Orihuela
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
- * E-mail:
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42
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Zhou M, Zhu F, Dong S, Pritchard DG, Wu H. A novel glucosyltransferase is required for glycosylation of a serine-rich adhesin and biofilm formation by Streptococcus parasanguinis. J Biol Chem 2010; 285:12140-8. [PMID: 20164186 DOI: 10.1074/jbc.m109.066928] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Fap1-like serine-rich glycoproteins are conserved in streptococci, staphylococci, and lactobacilli, and are required for bacterial biofilm formation and pathogenesis. Glycosylation of Fap1 is mediated by a gene cluster flanking the fap1 locus. The key enzymes responsible for the first step of Fap1 glycosylation are glycosyltransferases Gtf1 and Gtf2. They form a functional enzyme complex that catalyzes the transfer of N-acetylglucosamine (GlcNAc) residues to the Fap1 polypeptide. However, until now nothing was known about the subsequent step in Fap1 glycosylation. Here, we show that the second step in Fap1 glycosylation is catalyzed by nucleotide-sugar synthetase-like (Nss) protein. The nss gene located upstream of fap1 is also highly conserved in streptococci and lactobacilli. Nss-deficient mutants failed to catalyze the second step of Fap1 glycosylation in vivo in Streptococcus parasanguinis and in a recombinant Fap1 glycosylation system. Nss catalyzed the direct transfer of the glucosyl residue to the GlcNAc-modified Fap1 substrate in vitro, demonstrating that Nss is a glucosyltransferase. Thus we renamed Nss as glucosyltransferase 3 (Gtf3). A gtf3 mutant exhibited a biofilm defect. Taken together, we conclude that this new glucosyltransferase mediates the second step of Fap1 glycosylation and is required for biofilm formation.
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Affiliation(s)
- Meixian Zhou
- Department of Pediatric Dentistry, University of Alabama at Birmingham, Birmingham, Alabama 35244, USA
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43
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The Bifidobacterium dentium Bd1 genome sequence reflects its genetic adaptation to the human oral cavity. PLoS Genet 2009; 5:e1000785. [PMID: 20041198 PMCID: PMC2788695 DOI: 10.1371/journal.pgen.1000785] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 11/23/2009] [Indexed: 12/14/2022] Open
Abstract
Bifidobacteria, one of the relatively dominant components of the human intestinal microbiota, are considered one of the key groups of beneficial intestinal bacteria (probiotic bacteria). However, in addition to health-promoting taxa, the genus Bifidobacterium also includes Bifidobacterium dentium, an opportunistic cariogenic pathogen. The genetic basis for the ability of B. dentium to survive in the oral cavity and contribute to caries development is not understood. The genome of B. dentium Bd1, a strain isolated from dental caries, was sequenced to completion to uncover a single circular 2,636,368 base pair chromosome with 2,143 predicted open reading frames. Annotation of the genome sequence revealed multiple ways in which B. dentium has adapted to the oral environment through specialized nutrient acquisition, defences against antimicrobials, and gene products that increase fitness and competitiveness within the oral niche. B. dentium Bd1 was shown to metabolize a wide variety of carbohydrates, consistent with genome-based predictions, while colonization and persistence factors implicated in tissue adhesion, acid tolerance, and the metabolism of human saliva-derived compounds were also identified. Global transcriptome analysis demonstrated that many of the genes encoding these predicted traits are highly expressed under relevant physiological conditions. This is the first report to identify, through various genomic approaches, specific genetic adaptations of a Bifidobacterium taxon, Bifidobacterium dentium Bd1, to a lifestyle as a cariogenic microorganism in the oral cavity. In silico analysis and comparative genomic hybridization experiments clearly reveal a high level of genome conservation among various B. dentium strains. The data indicate that the genome of this opportunistic cariogen has evolved through a very limited number of horizontal gene acquisition events, highlighting the narrow boundaries that separate commensals from opportunistic pathogens.
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44
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Kerrigan SW, Cox D. The thrombotic potential of oral pathogens. J Oral Microbiol 2009; 1. [PMID: 21523210 PMCID: PMC3077004 DOI: 10.3402/jom.v1i0.1999] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 07/26/2009] [Accepted: 07/30/2009] [Indexed: 11/14/2022] Open
Abstract
In recent times the concept of infectious agents playing a role in cardiovascular disease has attracted much attention. Chronic oral disease such as periodontitis, provides a plausible route for entry of bacteria to the circulation. Upon entry to the circulation, the oral bacteria interact with platelets. It has been proposed that their ability to induce platelet aggregation and support platelet adhesion is a critical step in the pathogenesis of the infection process. Many published studies have demonstrated multiple mechanisms through which oral bacteria are able to bind to and activate platelets. This paper will review the various mechanisms oral bacteria use to interact with platelets.
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Affiliation(s)
- Steven W Kerrigan
- Cardiovascular Infection Group, School of Pharmacy, Royal College of Surgeons in Ireland, Dublin 2, Ireland
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45
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van Sorge NM, Quach D, Gurney MA, Sullam PM, Nizet V, Doran KS. The group B streptococcal serine-rich repeat 1 glycoprotein mediates penetration of the blood-brain barrier. J Infect Dis 2009; 199:1479-87. [PMID: 19392623 DOI: 10.1086/598217] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Group B Streptococcus (GBS) is the leading cause of bacterial meningitis in newborn infants. Because GBS is able to invade, survive, and cross the blood-brain barrier, we sought to identify surface-expressed virulence factors that contribute to blood-brain barrier penetration and the pathogenesis of meningitis. METHODS Targeted deletion and insertional mutants were generated in different GBS clinical isolates. Wild-type and mutant bacteria were analyzed for their capacity to adhere to and invade human brain microvascular endothelial cells (hBMECs) and to penetrate the blood-brain barrier using our model of hematogenous meningitis. RESULTS Analysis of a GBS (serotype V) clinical isolate revealed the presence of a surface-anchored serine-rich protein, previously designated serine-rich repeat 1 (Srr-1). GBS Srr-1 is a glycosylated protein with high molecular weight. Deletion of srr1 in NCTC 10/84 resulted in a significant decrease in adherence to and invasion of hBMECs. Additional mutants in other GBS serotypes commonly associated with meningitis showed a similar decrease in hBMEC invasion, compared with parental strains. Finally, in mice, wild-type GBS penetrated the blood-brain barrier and established meningitis more frequently than did the Deltasrr1 mutant strain. CONCLUSIONS Our data suggest that GBS Srr glycoproteins play an important role in crossing the blood-brain barrier and in the development of streptococcal meningitis.
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Affiliation(s)
- Nina M van Sorge
- Department of Pediatrics and 2Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California San Diego, La Jolla, San Diego, CA 92182, USA
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46
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Molecular dissection of the secA2 locus of group B Streptococcus reveals that glycosylation of the Srr1 LPXTG protein is required for full virulence. J Bacteriol 2009; 191:4195-206. [PMID: 19395494 DOI: 10.1128/jb.01673-08] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In streptococci, the secA2 locus includes genes encoding the following: (i) the accessory Sec components (SecA2, SecY2, and at least three accessory secretion proteins), (ii) two essential glycosyltranferases (GTs) (GtfA and GtfB), (iii) a variable number of dispensable additional GTs, and (iv) a secreted serine-rich LPXTG protein which is glycosylated in the cytoplasm and transported to the cell surface by this accessory Sec system. The secA2 locus of Streptococcus agalactiae strain NEM316 is structurally related to those found in other streptococci and encodes the serine-rich surface protein Srr1. We demonstrated that expression of Srr1 but not that of the SecA2 components and the associated GTs is regulated by the standalone transcriptional regulator Rga. Srr1 is synthesized as a glycosylated precursor, secreted by the SecA2 system, and anchored to the cell wall by the housekeeping sortase A. Srr1 was localized preferentially at the old poles. GtfA and/or GtfB, but not the six additional GTs, is essential for the production of Srr1. These GTs are involved in the attachment of GlcNac and sialic acid to Srr1. Full glycosylation of Srr1 is associated with the cell surface display of a protein that is more resistant to proteolytic attack. Srr1 contributes to bacterial adherence to human epithelial cell lines and virulence in a neonatal rat model. The extent of Srr1 glycosylation by GtfC to -H modulates bacterial adherence and virulence.
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47
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Genes and molecules of lactobacilli supporting probiotic action. Microbiol Mol Biol Rev 2009; 72:728-64, Table of Contents. [PMID: 19052326 DOI: 10.1128/mmbr.00017-08] [Citation(s) in RCA: 630] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Lactobacilli have been crucial for the production of fermented products for centuries. They are also members of the mutualistic microbiota present in the human gastrointestinal and urogenital tract. Recently, increasing attention has been given to their probiotic, health-promoting capacities. Many human intervention studies demonstrating health effects have been published. However, as not all studies resulted in positive outcomes, scientific interest arose regarding the precise mechanisms of action of probiotics. Many reported mechanistic studies have addressed mainly the host responses, with less attention being focused on the specificities of the bacterial partners, notwithstanding the completion of Lactobacillus genome sequencing projects, and increasing possibilities of genomics-based and dedicated mutant analyses. In this emerging and highly interdisciplinary field, microbiologists are facing the challenge of molecular characterization of probiotic traits. This review addresses the advances in the understanding of the probiotic-host interaction with a focus on the molecular microbiology of lactobacilli. Insight into the molecules and genes involved should contribute to a more judicious application of probiotic lactobacilli and to improved screening of novel potential probiotics.
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48
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Zhou M, Wu H. Glycosylation and biogenesis of a family of serine-rich bacterial adhesins. Microbiology (Reading) 2009; 155:317-327. [DOI: 10.1099/mic.0.025221-0] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glycosylation of bacterial proteins is an important process for bacterial physiology and pathophysiology. Both O- and N-linked glycan moieties have been identified in bacterial glycoproteins. The N-linked glycosylation pathways are well established in Gram-negative bacteria. However, the O-linked glycosylation pathways are not well defined due to the complex nature of known O-linked glycoproteins in bacteria. In this review, we examine a new family of serine-rich O-linked glycoproteins which are represented by fimbriae-associated adhesin Fap1 of Streptococcus parasanguinis and human platelet-binding protein GspB of Streptococcus gordonii. This family of glycoproteins is conserved in streptococcal and staphylococcal species. A gene cluster coding for glycosyltransferases and accessory Sec proteins has been implicated in the protein glycosylation. A two-step glycosylation model is proposed. Two glycosyltransferases interact with each other and catalyse the first step of the protein glycosylation in the cytoplasm; the cross-talk between glycosylation-associated proteins and accessory Sec components mediates the second step of the protein glycosylation, an emerging mechanism for bacterial O-linked protein glycosylation. Dissecting the molecular mechanism of this conserved biosynthetic pathway offers opportunities to develop new therapeutic strategies targeting this previously unrecognized pathway, as serine-rich glycoproteins have been shown to play a role in bacterial pathogenesis.
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Affiliation(s)
- Meixian Zhou
- Department of Pediatric Dentistry, UAB School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Hui Wu
- Department of Pediatric Dentistry, UAB School of Dentistry, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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49
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Li Y, Chen Y, Huang X, Zhou M, Wu R, Dong S, Pritchard DG, Fives-Taylor P, Wu H. A conserved domain of previously unknown function in Gap1 mediates protein-protein interaction and is required for biogenesis of a serine-rich streptococcal adhesin. Mol Microbiol 2008; 70:1094-104. [PMID: 18826412 DOI: 10.1111/j.1365-2958.2008.06456.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Fap1-like serine-rich proteins are a new family of bacterial adhesins found in a variety of streptococci and staphylococci that have been implicated in bacterial pathogenesis. A gene cluster encoding glycosyltransferases and accessory Sec components is required for Fap1 glycosylation and biogenesis in Streptococcus parasanguinis. Here we report that the glycosylation-associated protein, Gap1, contributes to glycosylation and biogenesis of Fap1 by interacting with another glycosylation-associated protein, Gap3. Gap1 shares structural homology with glycosyltransferases. The gap1 mutant, like the gap3 mutant, produced an aberrantly glycosylated Fap1 precursor and failed to produce mature Fap1, suggesting that Gap1 and Gap3 might function in concert in the Fap1 glycosylation and biogenesis. Indeed, Gap1 interacted with Gap3 in vitro and in vivo. A Gap1 N-terminal motif, within a highly conserved domain of unknown function (DUF1975) identified in many bacterial glycosyltransferases, was required for the Gap1-Gap3 interaction. Deletion of one, four and nine amino acids within the conserved motif gradually inhibited the Gap1-Gap3 interaction and diminished production of mature Fap1 and concurrently increased production of the Fap1 precursor. Consequently, bacterial adhesion to an in vitro tooth model was also reduced. These data demonstrate that the Gap1-Gap3 interaction is required for Fap1 biogenesis and Fap1-dependent bacterial adhesion.
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Affiliation(s)
- Yirong Li
- Department of Pediatric Dentistry, Schools of Dentistry and Medicine, University of Alabama, Birmingham, AL 35294, USA
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50
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Xiong YQ, Bensing BA, Bayer AS, Chambers HF, Sullam PM. Role of the serine-rich surface glycoprotein GspB of Streptococcus gordonii in the pathogenesis of infective endocarditis. Microb Pathog 2008; 45:297-301. [PMID: 18656529 DOI: 10.1016/j.micpath.2008.06.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Revised: 06/26/2008] [Accepted: 06/27/2008] [Indexed: 01/06/2023]
Abstract
The direct binding of bacteria to platelets is a central interaction in the pathogenesis of infective endocarditis. GspB is a serine-rich, cell wall glycoprotein of Streptococcus gordonii that mediates the binding of this organism to human platelets in vitro. To assess the contribution of this adhesin to the pathogenesis of endocarditis, we compared the virulence of S. gordonii M99 (which expresses GspB) with an isogenic, gspB mutant (PS846) in two rat models of endovascular infection. In the first group of experiments, animals were infected intravenously with M99 or PS846, and sacrificed 72 h later, to assess levels of bacteria within cardiac vegetations, kidneys, and spleens. When inoculated with 10(5)CFU, rats infected with PS846 had significantly lower densities of organisms within vegetations (mean: 3.84 log(10)CFU/g) as compared with M99-infected rats (6.67 log(10)CFU/g; P<0.001). Marked differences were also seen in rats co-infected with M99 and PS846, at a 1:1 ratio. While M99 was found at high levels within vegetations, kidneys and spleens (mean log(10)CFU/g: 6.62, 5.07 and 4.18, respectively) PS846 was not detected within these tissues. Thus, platelet binding by GspB appears to be a major interaction in the pathogenesis of endocarditis due to S. gordonii.
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Affiliation(s)
- Yan Q Xiong
- Department of Medicine, Harbor-UCLA Medical Center, 1000W Carson Street, Building RB2, Torrance, CA 90502, USA
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