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Krusenstjerna AC, Jusufovic N, Saylor TC, Stevenson B. DnaA modulates gene expression and morphologyof the Lyme Disease spirochete. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.598065. [PMID: 38895450 PMCID: PMC11185795 DOI: 10.1101/2024.06.08.598065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
All bacteria encode a multifunctional DNA-binding protein, DnaA, which initiates chromosomal replication. Despite having the most complex, segmented bacterial genome, little is known about Borrelia burgdorferi DnaA and its role in maintaining the spirochete's physiology. We utilized inducible CRISPR-interference and overexpression to modulate cellular levels of DnaA to better understand this essential protein. Dysregulation of DnaA, either up or down, significantly slowed replication and increased or decreased cell lengths. Using fluorescent microscopy, we found the DnaA CRISPRi mutants had increased numbers of chromosomes with irregular spacing patterns. The DnaA-depleted spirochetes also exhibited a significant defect in helical morphology. RNA-seq of the conditional mutants showed significant changes in the levels of transcripts involved with flagellar synthesis, elongation, cell division, virulence, and other functions. These findings demonstrate that the DnaA plays a commanding role in maintaining borrelial growth dynamics and protein expression, which are essential for the survival of the Lyme disease spirochete.
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Affiliation(s)
- Andrew C Krusenstjerna
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Nerina Jusufovic
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Timothy C Saylor
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky College of Medicine, Lexington, Kentucky, USA
- Department of Entomology, University of Kentucky, Lexington, Kentucky, USA
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Foor SD, Brangulis K, Shakya AK, Rana VS, Bista S, Kitsou C, Ronzetti M, Alreja AB, Linden SB, Altieri AS, Baljinnyam B, Akopjana I, Nelson DC, Simeonov A, Herzberg O, Caimano MJ, Pal U. A unique borrelial protein facilitates microbial immune evasion. mBio 2023; 14:e0213523. [PMID: 37830812 PMCID: PMC10653885 DOI: 10.1128/mbio.02135-23] [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: 08/10/2023] [Accepted: 08/14/2023] [Indexed: 10/14/2023] Open
Abstract
IMPORTANCE Lyme disease is a major tick-borne infection caused by a bacterial pathogen called Borrelia burgdorferi, which is transmitted by ticks and affects hundreds of thousands of people every year. These bacterial pathogens are distinct from other genera of microbes because of their distinct features and ability to transmit a multi-system infection to a range of vertebrates, including humans. Progress in understanding the infection biology of Lyme disease, and thus advancements towards its prevention, are hindered by an incomplete understanding of the microbiology of B. burgdorferi, partly due to the occurrence of many unique borrelial proteins that are structurally unrelated to proteins of known functions yet are indispensable for pathogen survival. We herein report the use of diverse technologies to examine the structure and function of a unique B. burgdorferi protein, annotated as BB0238-an essential virulence determinant. We show that the protein is structurally organized into two distinct domains, is involved in multiplex protein-protein interactions, and facilitates tick-to-mouse pathogen transmission by aiding microbial evasion of early host cellular immunity. We believe that our findings will further enrich our understanding of the microbiology of B. burgdorferi, potentially impacting the future development of novel prevention strategies against a widespread tick-transmitted infection.
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Affiliation(s)
- Shelby D. Foor
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Kalvis Brangulis
- Latvian Biomedical Research and Study Centre, Riga, Latvia
- Department of Human Physiology and Biochemistry, Riga Stradins University, Riga, Latvia
| | - Anil K. Shakya
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Vipin S. Rana
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Sandhya Bista
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Chrysoula Kitsou
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
| | - Michael Ronzetti
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Adit B. Alreja
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Sara B. Linden
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Amanda S. Altieri
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Bolormaa Baljinnyam
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Inara Akopjana
- Latvian Biomedical Research and Study Centre, Riga, Latvia
| | - Daniel C. Nelson
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
| | - Anton Simeonov
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland, USA
| | - Osnat Herzberg
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
- Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland, USA
| | - Melissa J. Caimano
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, Connecticut, USA
| | - Utpal Pal
- Department of Veterinary Medicine, University of Maryland, College Park, Maryland, USA
- Virginia-Maryland College of Veterinary Medicine, College Park, Maryland, USA
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Grąźlewska W, Holec-Gąsior L. Antibody Cross-Reactivity in Serodiagnosis of Lyme Disease. Antibodies (Basel) 2023; 12:63. [PMID: 37873860 PMCID: PMC10594444 DOI: 10.3390/antib12040063] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/25/2023] Open
Abstract
Lyme disease is a tick-borne disease caused by spirochetes belonging to the Borrelia burgdorferi sensu lato complex. The disease is characterized by a varied course; therefore, the basis for diagnosis is laboratory methods. Currently, a two-tiered serological test is recommended, using an ELISA as a screening test and a Western blot as a confirmatory test. This approach was introduced due to the relatively high number of false-positive results obtained when using an ELISA alone. However, even this approach has not entirely solved the problem of false-positive results caused by cross-reactive antibodies. Many highly immunogenic B. burgdorferi s.l. proteins are recognized nonspecifically by antibodies directed against other pathogens. This also applies to antigens, such as OspC, BmpA, VlsE, and FlaB, i.e., those commonly used in serodiagnostic assays. Cross-reactions can be caused by both bacterial (relapsing fever Borrelia, Treponema pallidum) and viral (Epstein-Baar virus, Cytomegalovirus) infections. Additionally, a rheumatoid factor has also been shown to nonspecifically recognize B. burgdorferi s.l. proteins, resulting in false-positive results. Therefore, it is necessary to carefully interpret the results of serodiagnostic tests so as to avoid overdiagnosis of Lyme disease, which causes unnecessary implementations of strong antibiotic therapies and delays in the correct diagnosis.
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Affiliation(s)
| | - Lucyna Holec-Gąsior
- Department of Molecular Biotechnology and Microbiology, Faculty of Chemistry, Gdansk University of Technology, 80-233 Gdansk, Poland;
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Stevenson B. The Lyme disease spirochete, Borrelia burgdorferi, as a model vector-borne pathogen: insights on regulation of gene and protein expression. Curr Opin Microbiol 2023; 74:102332. [PMID: 37279610 PMCID: PMC10524203 DOI: 10.1016/j.mib.2023.102332] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 04/26/2023] [Accepted: 05/03/2023] [Indexed: 06/08/2023]
Abstract
The Lyme disease spirochete persists in nature through cycles between ticks and vertebrates. Although the spirochete interacts with numerous, distinct tissues and environmental conditions during its infectious cycle, Borrelia burgdorferi appears to possess a limited ability to sense its external environment. This apparent paradox is being resolved through detailed investigations of the molecular mechanisms through which B. burgdorferi controls production of virulence-associated factors such as the Erp outer surface proteins. The results have led to development of a model for how B. burgdorferi controls expression of its diverse proteins, wherein physiological and metabolic states that are unique to specific points in the infectious cycle trigger changes in gene and protein expression levels.
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Affiliation(s)
- Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA; Department of Entomology, University of Kentucky, Lexington, KY, USA.
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Saylor TC, Savage CR, Krusenstjerna AC, Jusufovic N, Zückert WR, Brissette CA, Motaleb M, Schlax PJ, Stevenson B. Quantitative analyses of interactions between SpoVG and RNA/DNA. Biochem Biophys Res Commun 2023; 654:40-46. [PMID: 36889033 PMCID: PMC11086051 DOI: 10.1016/j.bbrc.2023.02.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/17/2023] [Indexed: 03/02/2023]
Abstract
The Borrelia burgdorferi SpoVG protein has previously been found to be a DNA- and RNA-binding protein. To aid in the elucidation of ligand motifs, affinities for numerous RNAs, ssDNAs, and dsDNAs were measured and compared. The loci used in the study were spoVG, glpFKD, erpAB, bb0242, flaB, and ospAB, with particular focus on the untranslated 5' portion of the mRNAs. Performing binding and competition assays yielded that the 5' end of spoVG mRNA had the highest affinity while the lowest observed affinity was to the 5' end of flaB mRNA. Mutagenesis studies of spoVG RNA and ssDNA sequences suggested that the formation of SpoVG-nucleic acid complexes are not entirely dependent on either sequence or structure. Additionally, exchanging uracil for thymine in ssDNAs did not affect protein-nucleic acid complex formation.
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Affiliation(s)
- Timothy C Saylor
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Christina R Savage
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Andrew C Krusenstjerna
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Nerina Jusufovic
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Wolfram R Zückert
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Catherine A Brissette
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Md Motaleb
- Department of Microbiology and Immunology, East Carolina University, Greenville, NC, USA
| | - Paula J Schlax
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA; Department of Entomology, University of Kentucky, Lexington, KY, USA.
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Stevenson B, Brissette CA. Erp and Rev Adhesins of the Lyme Disease Spirochete's Ubiquitous cp32 Prophages Assist the Bacterium during Vertebrate Infection. Infect Immun 2023; 91:e0025022. [PMID: 36853019 PMCID: PMC10016077 DOI: 10.1128/iai.00250-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023] Open
Abstract
Almost all spirochetes in the genus Borrelia (sensu lato) naturally contain multiple variants of closely related prophages. In the Lyme disease borreliae, these prophages are maintained as circular episomes that are called circular plasmid 32 kb (cp32s). The cp32s of Lyme agents are particularly unique in that they encode two distinct families of lipoproteins, namely, Erp and Rev, that are expressed on the bacterial outer surface during infection of vertebrate hosts. All identified functions of those outer surface proteins involve interactions between the spirochetes and host molecules, as follows: Erp proteins bind plasmin(ogen), laminin, glycosaminoglycans, and/or components of complement and Rev proteins bind fibronectin. Thus, cp32 prophages provide their bacterial hosts with surface proteins that can enhance infection processes, thereby facilitating their own survival. Horizontal transfer via bacteriophage particles increases the spread of beneficial alleles and creates diversity among Erp and Rev proteins.
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Affiliation(s)
- Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, Kentucky, USA
- Department of Entomology, University of Kentucky, Lexington, Kentucky, USA
| | - Catherine A. Brissette
- Department of Biomedical Sciences, University of North Dakota, Grand Forks, North Dakota, USA
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Saylor TC, Savage CR, Krusenstjerna AC, Jusufovic N, Zückert WR, Brissette CA, Motaleb M, Schlax PJ, Stevenson B. Quantitative analyses of interactions between SpoVG and RNA/DNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.06.527361. [PMID: 36860938 PMCID: PMC9976275 DOI: 10.1101/2023.02.06.527361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The Borrelia burgdorferi SpoVG protein has previously been found to be a DNA- and RNA-binding protein. To aid in the elucidation of ligand motifs, affinities for numerous RNAs, ssDNAs, and dsDNAs were measured and compared. The loci used in the study were spoVG, glpFKD, erpAB, bb0242, flaB, and ospAB, with particular focus on the untranslated 5' portion of the mRNAs. Performing binding and competition assays yielded that the 5' end of spoVG mRNA had the highest affinity while the lowest observed affinity was to the 5' end of flaB mRNA. Mutagenesis studies of spoVG RNA and ssDNA sequences suggested that the formation of SpoVG-nucleic acid complexes are not entirely dependent on either sequence or structure. Additionally, exchanging uracil for thymine in ssDNAs did not affect protein-nucleic acid complex formation.
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Affiliation(s)
- Timothy C. Saylor
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Christina R. Savage
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Andrew C. Krusenstjerna
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Nerina Jusufovic
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Wolfram R. Zückert
- Department of Microbiology, Molecular Genetics, and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Catherine A. Brissette
- Department of Biomedical Sciences, University of North Dakota, School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Md. Motaleb
- Department of Microbiology and Immunology, East Carolina University, Greenville, NC, USA
| | - Paula J. Schlax
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - Brian Stevenson
- Department of Microbiology, Immunology, and Molecular Genetics, University of Kentucky, Lexington, KY, USA
- Department of Entomology, University of Kentucky, Lexington, KY, USA
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Cordeiro TFVB, Gontijo MTP, Jorge GP, Brocchi M. EbfC/YbaB: A Widely Distributed Nucleoid-Associated Protein in Prokaryotes. Microorganisms 2022; 10:microorganisms10101945. [PMID: 36296221 PMCID: PMC9610160 DOI: 10.3390/microorganisms10101945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/13/2022] [Accepted: 09/20/2022] [Indexed: 11/06/2022] Open
Abstract
Genomic compaction is an essential characteristic of living organisms. Nucleoid-associated proteins (NAPs) are a group of small proteins that play crucial roles in chromosome architecture and affect DNA replication, transcription, and recombination by imposing topological alterations in genomic DNA, thereby modulating global gene expression. EbfC/YbaB was first described as a DNA-binding protein of Borrelia burgdorferi that regulates the expression of surface lipoproteins with roles in virulence. Further studies indicated that this protein binds specifically and non-specifically to DNA and colocalises with nucleoids in this bacterium. The data showed that this protein binds to DNA as a homodimer, although it can form other organised structures. Crystallography analysis indicated that the protein possesses domains responsible for protein–protein interactions and forms a “tweezer” structure probably involved in DNA binding. Moreover, sequence analysis revealed conserved motifs that may be associated with dimerisation. Structural analysis also showed that the tridimensional structure of EbfC/YbaB is highly conserved within the bacterial domain. The DNA-binding activity was observed in different bacterial species, suggesting that this protein can protect DNA during stress conditions. These findings indicate that EbfC/YbaB is a broadly distributed NAP. Here, we present a review of the existing data on this NAP.
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Garrigues RJ, Thomas S, Leong JM, Garcia BL. Outer surface lipoproteins from the Lyme disease spirochete exploit the molecular switch mechanism of the complement protease C1s. J Biol Chem 2022; 298:102557. [PMID: 36183830 PMCID: PMC9637899 DOI: 10.1016/j.jbc.2022.102557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 10/14/2022] Open
Abstract
Proteolytic cascades comprise several important physiological systems, including a primary arm of innate immunity called the complement cascade. To safeguard against complement-mediated attack, the etiologic agent of Lyme disease, Borreliella burgdorferi, produces numerous outer surface-localized lipoproteins that contribute to successful complement evasion. Recently, we discovered a pair of B. burgdorferi surface lipoproteins of the OspEF-related protein family-termed ElpB and ElpQ-that inhibit antibody-mediated complement activation. In this study, we investigate the molecular mechanism of ElpB and ElpQ complement inhibition using an array of biochemical and biophysical approaches. In vitro assays of complement activation show that an independently folded homologous C-terminal domain of each Elp protein maintains full complement inhibitory activity and selectively inhibits the classical pathway. Using binding assays and complement component C1s enzyme assays, we show that binding of Elp proteins to activated C1s blocks complement component C4 cleavage by competing with C1s-C4 binding without occluding the active site. C1s-mediated C4 cleavage is dependent on activation-induced binding sites, termed exosites. To test whether these exosites are involved in Elp-C1s binding, we performed site-directed mutagenesis, which showed that ElpB and ElpQ binding require C1s residues in the anion-binding exosite located on the serine protease domain of C1s. Based on these results, we propose a model whereby ElpB and ElpQ exploit activation-induced conformational changes that are normally important for C1s-mediated C4 cleavage. Our study expands the known complement evasion mechanisms of microbial pathogens and reveals a novel molecular mechanism for selective C1s inhibition by Lyme disease spirochetes.
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