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Sałamaszyńska-Guz A, Murawska M, Bącal P, Ostrowska A, Kwiecień E, Stefańska I, Douthwaite S. Increased Motility in Campylobacter jejuni and Changes in Its Virulence, Fitness, and Morphology Following Protein Expression on Ribosomes with Altered RsmA Methylation. Int J Mol Sci 2024; 25:9797. [PMID: 39337285 PMCID: PMC11431728 DOI: 10.3390/ijms25189797] [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: 08/01/2024] [Revised: 09/05/2024] [Accepted: 09/07/2024] [Indexed: 09/30/2024] Open
Abstract
Infection with Campylobacter jejuni is the major cause of human gastroenteritis in the United States and Europe, leading to debilitating autoimmune sequelae in many cases. While considerable progress has been made in detailing the infectious cycle of C. jejuni, a full understanding of the molecular mechanisms responsible for virulence remains to be elucidated. Here, we apply a novel approach by modulating protein expression on the pathogen's ribosomes by inactivating a highly conserved rRNA methyltransferase. Loss of the RsmA methyltransferase results in a more motile strain with greater adhesive and cell-invasive properties. These phenotypical effects correlate with enhanced expression of specific proteins related to flagellar formation and function, together with enzymes involved in cell wall/membrane and amino acid synthesis. Despite the enhancement of certain virulent traits, the null strain grows poorly on minimal media and is rapidly out-competed by the wild-type strain. Complementation with an active copy of the rsmA gene rescues most of the traits changed in the mutant. However, the complemented strain overexpresses rsmA and displays new flaws, including loss of the spiral cell shape, which is distinctive for C. jejuni. Proteins linked with altered virulence and morphology are identified here by mass spectrometry proteomic analyses of the strains.
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Affiliation(s)
- Agnieszka Sałamaszyńska-Guz
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences—SGGW, Ciszewskiego 8, 02-786 Warsaw, Poland; (M.M.); (E.K.); (I.S.)
| | - Małgorzata Murawska
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences—SGGW, Ciszewskiego 8, 02-786 Warsaw, Poland; (M.M.); (E.K.); (I.S.)
| | - Paweł Bącal
- Institute of Paleobiology, Polish Academy of Sciences, Twarda 51/55, 00-818 Warsaw, Poland;
| | - Agnieszka Ostrowska
- Department of Nanobiotechnology, Institute of Biology, Warsaw University of Live Sciences—SGGW, Ciszewskiego 8, 02-786 Warsaw, Poland;
| | - Ewelina Kwiecień
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences—SGGW, Ciszewskiego 8, 02-786 Warsaw, Poland; (M.M.); (E.K.); (I.S.)
| | - Ilona Stefańska
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences—SGGW, Ciszewskiego 8, 02-786 Warsaw, Poland; (M.M.); (E.K.); (I.S.)
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark
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Sabotič J, Janež N, Volk M, Klančnik A. Molecular structures mediating adhesion of Campylobacter jejuni to abiotic and biotic surfaces. Vet Microbiol 2023; 287:109918. [PMID: 38029692 DOI: 10.1016/j.vetmic.2023.109918] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 11/13/2023] [Accepted: 11/19/2023] [Indexed: 12/01/2023]
Abstract
Microaerophilic, Gram-negative Campylobacter jejuni is the causative agent of campylobacteriosis, the most common bacterial gastrointestinal infection worldwide. Adhesion is the crucial first step in both infection or interaction with the host and biofilm formation, and is a critical factor for bacterial persistence. Here we describe the proteins and other surface structures that promote adhesion to various surfaces, including abiotic surfaces, microorganisms, and animal and human hosts. In addition, we provide insight into the distribution of adhesion proteins among strains from different ecological niches and highlight unexplored proteins involved in C. jejuni adhesion. Protein-protein, protein-glycan, and glycan-glycan interactions are involved in C. jejuni adhesion, with different factors contributing to adhesion to varying degrees under different circumstances. As adhesion is essential for survival and persistence, it represents an interesting target for C. jejuni control. Knowledge of the adhesion process is incomplete, as different molecular and functional aspects have been studied for different structures involved in adhesion. Therefore, it is important to strive for an integration of different approaches to obtain a clearer picture of the adhesion process on different surfaces and to consider the involvement of proteins, glycoconjugates, and polysaccharides and their cooperation.
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Affiliation(s)
- Jerica Sabotič
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Nika Janež
- Department of Biotechnology, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Manca Volk
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Slovenia
| | - Anja Klančnik
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Slovenia.
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Keith BA, Harding JCS, Loewen ME. Mutational analysis of TlyA from Brachyspira hampsonii reveals two key residues conserved in pathogenic bacteria responsible for oligomerization and hemolytic activity. Biochim Biophys Acta Gen Subj 2022; 1866:130045. [PMID: 34715264 DOI: 10.1016/j.bbagen.2021.130045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 10/07/2021] [Accepted: 10/22/2021] [Indexed: 12/01/2022]
Abstract
BACKGROUND TlyA proteins are expressed in a variety of pathogenic bacteria and possess dual hemolytic and ribosomal RNA methyltransferase functions. While the mechanism of TlyA mediated rRNA methylation is well understood, relatively little is known about the mechanism of TlyA induced hemolysis. METHODS TlyA protein from the pig pathogen Brachyspira hampsonii was heterologously expressed and purified from an E. coli host. Hemolytic activity and rRNA methylation were assessed in vitro. Site-directed mutagenesis was used to mutate amino acids believed to be involved in TlyA mediated hemolysis. RESULTS Purified TlyA-His protein exhibited both hemolytic and rRNA methyltransferase activities in vitro, with partial inhibition of hemolysis observed under reducing conditions. Mutation of cysteine 80 to alanine impaired hemolytic activity. A C27A/C93A mutant was capable of dimerizing under non-reducing conditions, indicating that a C80-C80 disulfide bond is involved in TlyA oligomerization. A mutation conserved in several avirulent Brachyspira species (S9K) completely abolished hemolytic activity of TlyA. This loss of activity was attributed to impaired oligomerization in the S9K mutant, as assessed by ITC and size-exclusion chromatography experiments. CONCLUSIONS Oligomeric assembly and hemolytic activity of TlyA from Brachyspira hampsonii is dependent on the formation of an intermolecular C80-C80 disulfide bond and noncovalent interactions involving serine 9. The conservation of these amino acids in TlyA proteins from pathogenic bacteria suggests a correlation between tlyA gene mutations and bacterial virulence. GENERAL SIGNIFICANCE Our results further elucidate the mechanisms underlying TlyA mediated hemolysis and provide evidence of a conserved mechanism of oligomerization for TlyA family proteins.
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Affiliation(s)
- Brandon A Keith
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - John C S Harding
- Department of Large Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Matthew E Loewen
- Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada.
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Sałamaszyńska-Guz A, Rasmussen PK, Murawska M, Douthwaite S. Campylobacter jejuni Virulence Factors Identified by Modulating Their Synthesis on Ribosomes With Altered rRNA Methylation. Front Cell Infect Microbiol 2022; 11:803730. [PMID: 35096652 PMCID: PMC8794745 DOI: 10.3389/fcimb.2021.803730] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 12/17/2021] [Indexed: 12/02/2022] Open
Abstract
Campylobacter jejuni is a major cause of food poisoning worldwide, and remains the main infective agent in gastroenteritis and related intestinal disorders in Europe and the USA. As with all bacterial infections, the stages of adhesion to host tissue, survival in the host and eliciting disease all require the synthesis of proteinaceous virulence factors on the ribosomes of the pathogen. Here, we describe how C. jejuni virulence is attenuated by altering the methylation of its ribosomes to disrupt the composition of its proteome, and how this in turn provides a means of identifying factors that are essential for infection and pathogenesis. Specifically, inactivation of the C. jejuni Cj0588/TlyA methyltransferase prevents methylation of nucleotide C1920 in the 23S rRNA of its ribosomes and reduces the pathogen’s ability to form biofilms, to attach, invade and survive in host cells, and to provoke the innate immune response. Mass spectrometric analyses of C. jejuni TlyA-minus strains revealed an array of subtle changes in the proteome composition. These included reduced amounts of the cytolethal distending toxin (CdtC) and the MlaEFD proteins connected with outer membrane vesicle (OMV) production. Inactivation of the cdtC and mlaEFD genes confirmed the importance of their encoded proteins in establishing infection. Collectively, the data identify a subset of genes required for the onset of human campylobacteriosis, and serve as a proof of principle for use of this approach in detecting proteins involved in bacterial pathogenesis.
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Affiliation(s)
- Agnieszka Sałamaszyńska-Guz
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
- *Correspondence: Agnieszka Sałamaszyńska-Guz, ; Stephen Douthwaite,
| | | | - Małgorzata Murawska
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Life Sciences – SGGW, Warsaw, Poland
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
- *Correspondence: Agnieszka Sałamaszyńska-Guz, ; Stephen Douthwaite,
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Sharma M, Singh P. Role of TlyA in the Biology of Uncultivable Mycobacteria. Comb Chem High Throughput Screen 2022; 25:1587-1594. [PMID: 35021968 DOI: 10.2174/1386207325666220111150923] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Revised: 10/25/2021] [Accepted: 11/05/2021] [Indexed: 11/22/2022]
Abstract
TlyA proteins are related to distinct functions in a diverse spectrum of bacterial pathogens including mycobacterial spp. There are several annotated proteins function as hemolysin or pore forming molecules that play an important role in the virulence of pathogenic organisms. Many studies reported the dual activity of mycobacterial TlyA as 'hemolysin' and 'S-adenosylmethionine dependent rRNA methylase'. To act as a hemolysin, a sequence must have a signal sequence and transmembrane segment which helps the protein to enter the extracellular environment. Interestingly, the mycobacterial tlyA has neither a traditional signal sequences of general/sec/tat pathways nor any transmembrane segments are present. Still it can reach the extracellular milieu with the help of non-classical signal mechanisms. Also, retention of tlyA in cultivable mycobacterial pathogens (such as Mycobacterium tuberculosis and M. marinum) as well as uncultivated mycobacterial pathogens despite their extreme reductive evolution (such as M. leprae, M. lepromatosis and M. uberis) suggests its crucial role in evolutionary biology of pathogenic mycobacteria. Numerous virulence factors have been characterised from the uncultivable mycobacteria but the information of TlyA protein is still limited in terms of molecular and structural characterisation. The genomic insights offered by comparative analysis of TlyA sequences and its conserved domains reveal its pore forming activity which further confirms its role as a virulence protein, particularly in uncultivable mycobacteria. Therefore, this review presents a comparative analysis of mycobacterial TlyA family by sequence homology and alignment to improve our understanding of this unconventional hemolysin and RNA methyltransferase TlyA of uncultivable mycobacteria.
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Affiliation(s)
- Mukul Sharma
- ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
| | - Pushpendra Singh
- ICMR-National Institute of Research in Tribal Health, Jabalpur, Madhya Pradesh, India
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Sałamaszyńska-Guz A, Serafińska I, Bącal P, Douthwaite S. Virulence properties of Campylobacter jejuni are enhanced by displaying a mycobacterial TlyA methylation pattern in its rRNA. Cell Microbiol 2020; 22:e13199. [PMID: 32134554 PMCID: PMC7317525 DOI: 10.1111/cmi.13199] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/24/2020] [Accepted: 02/23/2020] [Indexed: 01/18/2023]
Abstract
Campylobacter jejuni is a bacterial pathogen that is generally acquired as a zoonotic infection from poultry and animals. Adhesion of C. jejuni to human colorectal epithelial cells is weakened after loss of its cj0588 gene. The Cj0588 protein belongs to the type I group of TlyA (TlyAI) enzymes, which 2′‐O‐methylate nucleotide C1920 in 23S rRNA. Slightly longer TlyAII versions of the methyltransferase are found in actinobacterial species including Mycobacterium tuberculosis, and methylate not only C1920 but also nucleotide C1409 in 16S rRNA. Loss of TlyA function attenuates virulence of both M. tuberculosis and C. jejuni. We show here that the traits impaired in C. jejuni null strains can be rescued by complementation not only with the original cj0588 (tlyAI) but also with a mycobacterial tlyAII gene. There are, however, significant differences in the recombinant phenotypes. While cj0588 restores motility, biofilm formation, adhesion to and invasion of human epithelial cells and stimulation of IL‐8 production in a C. jejuni null strain, several of these properties are further enhanced by the mycobacterial tlyAII gene, in some cases to twice the original wild‐type level. These findings strongly suggest that subtle changes in rRNA modification patterns can affect protein synthesis in a manner that has serious consequences for bacterial pathogenicity.
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Affiliation(s)
- Agnieszka Sałamaszyńska-Guz
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences - SGGW, Warsaw, Poland
| | - Izabela Serafińska
- Division of Microbiology, Department of Pre-Clinical Sciences, Institute of Veterinary Medicine, Warsaw University of Live Sciences - SGGW, Warsaw, Poland
| | - Paweł Bącal
- Laboratory of Theory and Applications of Electrodes, Faculty of Chemistry, University of Warsaw, Warsaw, Poland.,Nałęcz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Stephen Douthwaite
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense M, Denmark
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