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Lauber F, Deme JC, Liu X, Kjær A, Miller HL, Alcock F, Lea SM, Berks BC. Structural insights into the mechanism of protein transport by the Type 9 Secretion System translocon. Nat Microbiol 2024; 9:1089-1102. [PMID: 38538833 PMCID: PMC10994853 DOI: 10.1038/s41564-024-01644-7] [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: 10/30/2023] [Accepted: 02/19/2024] [Indexed: 04/06/2024]
Abstract
Secretion systems are protein export machines that enable bacteria to exploit their environment through the release of protein effectors. The Type 9 Secretion System (T9SS) is responsible for protein export across the outer membrane (OM) of bacteria of the phylum Bacteroidota. Here we trap the T9SS of Flavobacterium johnsoniae in the process of substrate transport by disrupting the T9SS motor complex. Cryo-EM analysis of purified substrate-bound T9SS translocons reveals an extended translocon structure in which the previously described translocon core is augmented by a periplasmic structure incorporating the proteins SprE, PorD and a homologue of the canonical periplasmic chaperone Skp. Substrate proteins bind to the extracellular loops of a carrier protein within the translocon pore. As transport intermediates accumulate on the translocon when energetic input is removed, we deduce that release of the substrate-carrier protein complex from the translocon is the energy-requiring step in T9SS transport.
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Affiliation(s)
- Frédéric Lauber
- Department of Biochemistry, University of Oxford, Oxford, UK
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium
| | - Justin C Deme
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
- The Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford, UK
| | - Xiaolong Liu
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Andreas Kjær
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Helen L Miller
- Biological Physics Research Group, Department of Physics, University of Oxford, Oxford, UK
| | - Felicity Alcock
- Department of Biochemistry, University of Oxford, Oxford, UK
- Newcastle University Biosciences Institute, Newcastle University, Newcastle, UK
| | - Susan M Lea
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD, USA.
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK.
- The Central Oxford Structural Molecular Imaging Centre (COSMIC), University of Oxford, Oxford, UK.
| | - Ben C Berks
- Department of Biochemistry, University of Oxford, Oxford, UK.
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Szczęśniak K, Veillard F, Scavenius C, Chudzik K, Ferenc K, Bochtler M, Potempa J, Mizgalska D. The Bacteroidetes Q-rule and glutaminyl cyclase activity increase the stability of extracytoplasmic proteins. mBio 2023; 14:e0098023. [PMID: 37750700 PMCID: PMC10653852 DOI: 10.1128/mbio.00980-23] [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: 04/23/2023] [Accepted: 08/07/2023] [Indexed: 09/27/2023] Open
Abstract
IMPORTANCE Exclusively in the Bacteroidetes phylum, most proteins exported across the inner membrane via the Sec system and released into the periplasm by type I signal peptidase have N-terminal glutamine converted to pyroglutamate. The reaction is catalyzed by the periplasmic enzyme glutaminyl cyclase (QC), which is essential for the growth of Porphyromonas gingivalis and other periodontopathogens. Apparently, pyroglutamyl formation stabilizes extracytoplasmic proteins and/or protects them from proteolytic degradation in the periplasm. Given the role of P. gingivalis as the keystone pathogen in periodontitis, P. gingivalis QC is a promising target for the development of drugs to treat and/or prevent this highly prevalent chronic inflammatory disease leading to tooth loss and associated with severe systemic diseases.
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Affiliation(s)
- Katarzyna Szczęśniak
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Florian Veillard
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Carsten Scavenius
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Kamila Chudzik
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Kinga Ferenc
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Matthias Bochtler
- International Institute of Molecular and Cell Biology, Warsaw, Poland
- Polish Academy of Sciences, Institute of Biochemistry and Biophysics, Warsaw, Poland
| | - Jan Potempa
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of Dentistry, Louisville, Kentucky, USA
| | - Danuta Mizgalska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
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Phillips PL, Wu XJ, Reyes L. Differential affinity chromatography reveals a link between Porphyromonas gingivalis-induced changes in vascular smooth muscle cell differentiation and the type 9 secretion system. Front Cell Infect Microbiol 2022; 12:983247. [PMID: 36483452 PMCID: PMC9722745 DOI: 10.3389/fcimb.2022.983247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 10/24/2022] [Indexed: 11/23/2022] Open
Abstract
Porphyromonas gingivalis is implicated in adverse pregnancy outcome. We previously demonstrated that intrauterine infection with various strains of P. gingivalis impairs the physiologic remodeling of the uterine spiral arteries (IRSA) during pregnancy, which underlies the major obstetrical syndromes. Women diagnosed with IRSA also have a greater risk for premature cardiovascular disease in later life. The dysregulated plasticity of vascular smooth muscle cells (VSMCs) is present in both IRSA and premature cardiovascular events. We hypothesized that VSMCs could serve as a bait to identify P. gingivalis proteins associated with dysregulated VSMC plasticity as seen in IRSA. We first confirmed that dams with P. gingivalis A7UF-induced IRSA also show perturbed aortic smooth muscle cell (AoSMC) plasticity along with the P. gingivalis colonization of the tissue. The in vitro infection of AoSMCs with IRSA-inducing strain A7UF also perturbed AoSMC plasticity that did not occur with infection by non-IRSA-inducing strain W83. Far-Western blotting with strain W83 and strain A7UF showed a differential binding pattern to the rat aorta and primary rat AoSMCs. The affinity chromatography/pull-down assay combined with mass spectrometry was used to identify P. gingivalis/AoSMC protein interactions specific to IRSA. Membrane proteins with a high binding affinity to AoSMCs were identified in the A7UF pull-down but not in the W83 pull-down, most of which were the outer membrane components of the Type 9 secretion system (T9SS) and T9SS cargo proteins. Additional T9SS cargo proteins were detected in greater abundance in the A7UF pull-down eluate compared to W83. None of the proteins enriched in the W83 eluate were T9SS components nor T9SS cargo proteins despite their presence in the prey preparations used in the pull-down assay. In summary, differential affinity chromatography established that the components of IRSA-inducing P. gingivalis T9SS as well as its cargo directly interact with AoSMCs, which may play a role in the infection-induced dysregulation of VSMC plasticity. The possibility that the T9SS is involved in the microbial manipulation of host cell events important for cell differentiation and tissue remodeling would constitute a new virulence function for this system.
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Affiliation(s)
- Priscilla L. Phillips
- Microbiology and Immunology, A.T. Still University of Health Sciences, Kirksville College of Osteopathic Medicine, Kirksville, MO, United States
| | - Xiao-jun Wu
- Department of Pathobiological Sciences, University of Wisconsin - Madison, School of Veterinary Medicine, Madison, WI, United States
| | - Leticia Reyes
- Department of Pathobiological Sciences, University of Wisconsin - Madison, School of Veterinary Medicine, Madison, WI, United States,*Correspondence: Leticia Reyes,
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Wang H, Peng W, Zhang G, Jiang M, Zhao J, Zhao X, Pan Y, Lin L. Role of PG0192 and PG0193 in the modulation of pro-inflammatory cytokines in macrophages in response to Porphyromonas gingivalis. Eur J Oral Sci 2022; 130:e12851. [PMID: 35049069 DOI: 10.1111/eos.12851] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 12/28/2021] [Indexed: 12/25/2022]
Abstract
Porphyromonas gingivalis is the main pathogen of chronic periodontitis. However, the specific mechanisms through which P. gingivalis induces immune and inflammatory responses in periodontitis have not been completely elucidated. In this study, we investigated the effects of the P. gingivalis outer membrane protein OmpH (encoded by PG0192 and PG0193) on interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression in macrophages to assess the pro-inflammatory cytokine responses. A PG0192-PG0193 deletion mutant strain and a com△PG0192-0193 strain were constructed. Furthermore, rOmpH-1 and rOmpH-2 encoded by PG0192 and PG0193, respectively, were cloned, expressed, and purified for subsequent experiments. Notably, the expression of IL-6 and TNF-α at mRNA and protein levels was downregulated upon treatment of macrophages with the PG0192-PG0193 deletion mutant strain, whereas treatment of macrophages with P. gingivalis W83 co-incubated with rOmpH-1 or rOmpH-2 upregulated IL-6 and TNF-α mRNA levels. The addition of C5aR antagonist blocked this induction. Overall, our findings provided important insights into the roles of PG0192 and PG0193 for promoting IL-6 and TNF-α expression in macrophages exposed to P. gingivalis and revealed the involvement of C5aR in the pro-inflammatory response.
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Affiliation(s)
- Hongyan Wang
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China
| | - Wenying Peng
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China.,Department of Oral Medicine, Luohu District, Shenzhen Stomatological Hospital, Shenzhen, China
| | - Guangyu Zhang
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China.,China Aerospace Science & Industry Corp 731 Hospital, Beijing, China
| | - Muzhou Jiang
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China
| | - Jian Zhao
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China
| | - Xue Zhao
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China
| | - Yaping Pan
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China
| | - Li Lin
- Department of Periodontology, School of Stomatology, China Medical University, Shenyang, Liaoning Province, China
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Nakayama M, Naito M, Omori K, Ono S, Nakayama K, Ohara N. Porphyromonas gingivalis Gingipains Induce Cyclooxygenase-2 Expression and Prostaglandin E 2 Production via ERK1/2-Activated AP-1 (c-Jun/c-Fos) and IKK/NF-κB p65 Cascades. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1146-1154. [PMID: 35110422 DOI: 10.4049/jimmunol.2100866] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 12/13/2021] [Indexed: 06/14/2023]
Abstract
Porphyromonas gingivalis is commonly known as one of the major pathogens contributing to periodontitis, and its persistent infection may increase the risk for the disease. The proinflammatory mediators, including IL-6, TNF-α, and cyclooxygenase-2 (COX-2)/PGE2, are closely associated with progression of periodontitis. In this study, we focused on the cysteine protease "gingipains," lysine-specific gingipain, arginine-specific gingipain (Rgp) A, and RgpB, produced by P. gingivalis, and used the wild-type strain and several gene-deletion mutants (rgpA, rgpB, kgp, and fimA) to elucidate the involvement of gingipains in COX-2 expression and PGE2 production. We infected human monocytes, which are THP-1 cells and primary monocytes, with these bacterial strains and found that gingipains were involved in induction of COX-2 expression and PGE2 production. We have shown that the protease activity of gingipains was crucial for these events by using gingipain inhibitors. Furthermore, activation of ERK1/2 and IκB kinase was required for gingipain-induced COX-2 expression/PGE2 production, and these kinases activated two transcription factors, c-Jun/c-Fos (AP-1) and NF-κB p65, respectively. In particular, these data suggest that gingipain-induced c-Fos expression via ERK is essential for AP-1 formation with c-Jun, and activation of AP-1 and NF-κB p65 plays a central role in COX-2 expression/PGE2 production. Thus, we show the (to our knowledge) novel finding that gingipains with the protease activity from P. gingivalis induce COX-2 expression and PGE2 production via activation of MEK/ERK/AP-1 and IκB kinase/NF-κB p65 in human monocytes. Hence it is likely that gingipains closely contribute to the inflammation of periodontal tissues.
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Affiliation(s)
- Masaaki Nakayama
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama, Japan
| | - Mariko Naito
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan; and
| | - Kazuhiro Omori
- Department of Periodontics and Endodontics, Okayama University Hospital, Okayama, Japan
- Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama, Japan
| | - Shintaro Ono
- Department of Periodontics and Endodontics, Okayama University Hospital, Okayama, Japan
| | - Koji Nakayama
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan; and
| | - Naoya Ohara
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan;
- Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama, Japan
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Yao K, Cai JY, Zhao L, Wu YF, Zhao ZH, Shen DN. Research progress on two-component signal transduction systems in Porphyromonas gingivalis. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2021; 39:88-93. [PMID: 33723942 DOI: 10.7518/hxkq.2021.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Porphyromonas gingivalis (P. gingivalis), a Gram-negative oral anaerobe, is considered to be a major pathogenic agent involved in the onset and progression of chronic periodontitis. P. gingivalis must be able to perceive and respond to the complicated changes in host to survive the environmental challenges, in which the two-component signal transduction systems (TCSs) play critical roles by connecting input signals to cellular physiological output. Canonical TCS consists of a sensor histidine kinase and a cognate response regulator that functions via a phosphorylation cascade. In this review, the roles of TCSs in P. gingivalis were demonstrated by illustrating the target genes and modulation modes, which may help elucidate the underlying mechanisms in future studies.
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Affiliation(s)
- Ke Yao
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Jing-Yi Cai
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Lei Zhao
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Ya-Fei Wu
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Zhi-He Zhao
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
| | - Dao-Nan Shen
- State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases & West China Hospital of Stomatology, Sichuan University, Chengdu 610041, China
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Lunar Silva I, Cascales E. Molecular Strategies Underlying Porphyromonas gingivalis Virulence. J Mol Biol 2021; 433:166836. [PMID: 33539891 DOI: 10.1016/j.jmb.2021.166836] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/15/2021] [Accepted: 01/15/2021] [Indexed: 02/07/2023]
Abstract
The anaerobic Gram-negative bacterium Porphyromonas gingivalis is considered the keystone of periodontitis diseases, a set of inflammatory conditions that affects the tissues surrounding the teeth. In the recent years, the major virulence factors exploited by P. gingivalis have been identified and characterized, including a cocktail of toxins, mainly proteases called gingipains, which promote gingival tissue invasion. These effectors use the Sec pathway to cross the inner membrane and are then recruited and transported across the outer membrane by the type IX secretion system (T9SS). In P. gingivalis, most secreted effectors are attached to anionic lipopolysaccharides (A-LPS), and hence form a virulence coat at the cell surface. P. gingivalis produces additional virulence factors to evade host immune responses, such as capsular polysaccharide, fimbriae and outer membrane vesicles. In addition to periodontitis, it is proposed that this broad repertoire of virulence factors enable P. gingivalis to be involved in diverse human diseases such as rheumatoid arthritis, and neurodegenerative, Alzheimer, and cardiovascular disorders. Here, we review the major virulence determinants of P. gingivalis and discuss future directions to better understand their mechanisms of action.
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Affiliation(s)
- Ignacio Lunar Silva
- Laboratoire d'Ingénierie des Syst èmes Macromol éculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), UMR7255, 31 Chemin Joseph Aiguier CS7071, 13009 Marseille Cedex 20, France.
| | - Eric Cascales
- Laboratoire d'Ingénierie des Syst èmes Macromol éculaires (LISM), Institut de Microbiologie, Bioénergies and Biotechnologie (IM2B), Aix-Marseille Université, Centre National de la Recherche Scientifique (CNRS), UMR7255, 31 Chemin Joseph Aiguier CS7071, 13009 Marseille Cedex 20, France.
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Abstract
The functional diversity of the mammalian intestinal microbiome far exceeds that of the host organism, and microbial genes contribute substantially to the well-being of the host. However, beneficial gut organisms can also be pathogenic when present in the gut or other locations in the body. Among dominant beneficial bacteria are several species of Bacteroides, which metabolize polysaccharides and oligosaccharides, providing nutrition and vitamins to the host and other intestinal microbial residents. These topics and the specific organismal and molecular interactions that are known to be responsible for the beneficial and detrimental effects of Bacteroides species in humans comprise the focus of this review. The complexity of these interactions will be revealed.
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Affiliation(s)
- Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, USA
- Department of Microbiology and Molecular Genetics, Faculty of Life Sciences, University of Okara,Okara, PunjabPakistan
| | - Milton H. Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, USA
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PorA, a conserved C-terminal domain-containing protein, impacts the PorXY-SigP signaling of the type IX secretion system. Sci Rep 2020; 10:21109. [PMID: 33273542 PMCID: PMC7712824 DOI: 10.1038/s41598-020-77987-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 11/19/2020] [Indexed: 01/07/2023] Open
Abstract
Porphyromonas gingivalis, a periodontal pathogen, translocates many virulence factors including the cysteine proteases referred to as gingipains to the cell surface via the type IX secretion system (T9SS). Expression of the T9SS component proteins is regulated by the tandem signaling of the PorXY two-component system and the ECF sigma factor SigP. However, the details of this regulatory pathway are still unknown. We found that one of the T9SS conserved C-terminal domain-containing proteins, PGN_0123, which we have designated PorA, is involved in regulating expression of genes encoding T9SS structural proteins and that PorA can be translocated onto the cell surface without the T9SS translocation machinery. X-ray crystallography revealed that PorA has a domain similar to the mannose-binding domain of Escherichia coli FimH, the tip protein of Type 1 pilus. Mutations in the cytoplasmic domain of the sensor kinase PorY conferred phenotypic recovery on the ΔporA mutant. The SigP sigma factor, which is activated by the PorXY two-component system, markedly decreased in the ΔporA mutant. These results strongly support a potential role for PorA in relaying a signal from the cell surface to the PorXY-SigP signaling pathway.
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Shahriar ASM, Ono S, Nakayama M, Ohara N, Ohara N. Construction and characterization of the PGN_0296 mutant of Porphyromonas gingivalis. J Oral Biosci 2020; 62:322-326. [PMID: 33038516 DOI: 10.1016/j.job.2020.09.007] [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: 09/03/2020] [Revised: 09/16/2020] [Accepted: 09/09/2020] [Indexed: 10/23/2022]
Abstract
The periodontal pathogen Porphyromonas gingivalis produces gingipains (Kgp, RgpA, and RgpB), cysteine proteases involved in the organism's virulence, and pigmentation. We previously showed that deletion of the PGN_0297 and PGN_0300 genes reduced the proteolytic activity of gingipains. The role of the PGN_0296 gene, consisting of an operon with the PGN_0297 and PGN_0300 genes, is unclear. Herein, we examined the effect of PGN_0296 gene deletion on the proteolytic activity. Although the proteolytic activity of the gingipains did not decrease in the culture supernatant of a PGN_0296 gene deletion mutant (ΔPGN_0296), the growth was delayed.
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Affiliation(s)
- Abu Saleh Muhammad Shahriar
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Shintaro Ono
- Department of Periodontal Sciences, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
| | - Masaaki Nakayama
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama, Japan
| | - Naoko Ohara
- Department of Operative Dentistry, Okayama University Hospital, Okayama University, Okayama, Japan
| | - Naoya Ohara
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan; Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama, Japan.
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Emrizal R, Nor Muhammad NA. Phylogenetic comparison between Type IX Secretion System (T9SS) protein components suggests evidence of horizontal gene transfer. PeerJ 2020; 8:e9019. [PMID: 32617187 PMCID: PMC7323717 DOI: 10.7717/peerj.9019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 03/28/2020] [Indexed: 12/20/2022] Open
Abstract
Porphyromonas gingivalis is one of the major bacteria that causes periodontitis. Chronic periodontitis is a severe form of periodontal disease that ultimately leads to tooth loss. Virulence factors that contribute to periodontitis are secreted by Type IX Secretion System (T9SS). There are aspects of T9SS protein components that have yet to be characterised. Thus, the aim of this study is to investigate the phylogenetic relationship between members of 20 T9SS component protein families. The Bayesian Inference (BI) trees for 19 T9SS protein components exhibit monophyletic clades for all major classes under Bacteroidetes with strong support for the monophyletic clades or its subclades that is consistent with phylogeny exhibited by the constructed BI tree of 16S rRNA. The BI tree of PorR is different from the 19 BI trees of T9SS protein components as it does not exhibit monophyletic clades for all major classes under Bacteroidetes. There is strong support for the phylogeny exhibited by the BI tree of PorR which deviates from the phylogeny based on 16S rRNA. Hence, it is possible that the porR gene is subjected to horizontal transfer as it is known that virulence factor genes could be horizontally transferred. Seven genes (porR included) that are involved in the biosynthesis of A-LPS are found to be flanked by insertion sequences (IS5 family transposons). Therefore, the intervening DNA segment that contains the porR gene might be transposed and subjected to conjugative transfer. Thus, the seven genes can be co-transferred via horizontal gene transfer. The BI tree of UgdA does not exhibit monophyletic clades for all major classes under Bacteroidetes which is similar to the BI tree of PorR (both are a part of the seven genes). Both BI trees also exhibit similar topology as the four identified clusters with strong support and have similar relative positions to each other in both BI trees. This reinforces the possibility that porR and the other six genes might be horizontally transferred. Other than the BI tree of PorR, the 19 other BI trees of T9SS protein components also exhibit evidence of horizontal gene transfer. However, their genes might undergo horizontal gene transfer less frequently compared to porR because the intervening DNA segment that contains porR is easily exchanged between bacteria under Bacteroidetes due to the presence of insertion sequences (IS5 family transposons) that flank it. In conclusion, this study can provide a better understanding about the phylogeny of T9SS protein components.
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Affiliation(s)
- Reeki Emrizal
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia
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Gingimaps: Protein Localization in the Oral Pathogen Porphyromonas gingivalis. Microbiol Mol Biol Rev 2020; 84:84/1/e00032-19. [PMID: 31896547 DOI: 10.1128/mmbr.00032-19] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Porphyromonas gingivalis is an oral pathogen involved in the widespread disease periodontitis. In recent years, however, this bacterium has been implicated in the etiology of another common disorder, the autoimmune disease rheumatoid arthritis. Periodontitis and rheumatoid arthritis were known to correlate for decades, but only recently a possible molecular connection underlying this association has been unveiled. P. gingivalis possesses an enzyme that citrullinates certain host proteins and, potentially, elicits autoimmune antibodies against such citrullinated proteins. These autoantibodies are highly specific for rheumatoid arthritis and have been purported both as a symptom and a potential cause of the disease. The citrullinating enzyme and other major virulence factors of P. gingivalis, including some that were implicated in the etiology of rheumatoid arthritis, are targeted to the host tissue as secreted or outer-membrane-bound proteins. These targeting events play pivotal roles in the interactions between the pathogen and its human host. Accordingly, the overall protein sorting and secretion events in P. gingivalis are of prime relevance for understanding its full disease-causing potential and for developing preventive and therapeutic approaches. The aim of this review is therefore to offer a comprehensive overview of the subcellular and extracellular localization of all proteins in three reference strains and four clinical isolates of P. gingivalis, as well as the mechanisms employed to reach these destinations.
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He YU, Wang S, Yin X, Sun F, He B, Liu X. Comparison of Extracellular Proteins from Virulent and Avirulent Vibrio parahaemolyticus Strains To Identify Potential Virulence Factors. J Food Prot 2020; 83:155-162. [PMID: 31860395 DOI: 10.4315/0362-028x.jfp-19-188] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Vibrio parahaemolyticus is a leading seafood-borne pathogen that causes gastroenteritis, septicemia, and serious wound infections due to the actions of virulence-associated proteins. We compared the extracellular proteins of nonvirulent JHY20 and virulent ATCC 33847 V. parahaemolyticus reference strains. Eighteen extracellular proteins were identified from secretory profiles, and 11 (68.75%) of the 16 proteins in ATCC 33847 are associated with virulence and/or protection against adverse conditions: trigger factor, chaperone SurA, aspartate-semialdehyde dehydrogenase, 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase, glutamate 5-kinase, alanine dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, outer membrane protein OmpV, ribosome-associated inhibitor A, chaperone protein Skp, and universal stress protein. Two nontoxic-related proteins, amino acid ABC transporter substrate-binding protein and an uncharacterized protein, were identified in JHY20. The results provide a theoretical basis for supporting safety risk assessment of aquatic foods, illuminate the pathogenic mechanisms of V. parahaemolyticus, and assist the identification of novel vaccine candidates for foodborne pathogens.
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Affiliation(s)
- Y U He
- College of Food (Biotechnology) Engineering.,Key Construction Laboratory of Food Resources Development and the Quality Safety, Xuzhou University of Technology, Jiangsu, Xuzhou 221018, People's Republic of China
| | - Shuai Wang
- College of Food (Biotechnology) Engineering.,Key Construction Laboratory of Food Resources Development and the Quality Safety, Xuzhou University of Technology, Jiangsu, Xuzhou 221018, People's Republic of China
| | | | - Fengjiao Sun
- Logistics & Security Department, Shanghai Civil Aviation College, Shanghai 201300, People's Republic of China
| | - Bin He
- Environment Monitoring Station, Zaozhuang Municipal Bureau of Ecology and Environment, Shandong 277100, People's Republic of China
| | - Xiao Liu
- Henan Key Laboratory of Cold Chain Food Quality and Safety Control, Zhengzhou University of Light Industry, Zhengzhou 450001, People's Republic of China
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14
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Chen Z, Wang X, Ren X, Han W, Malhi KK, Ding C, Yu S. Riemerella anatipestifer GldM is required for bacterial gliding motility, protein secretion, and virulence. Vet Res 2019; 50:43. [PMID: 31164171 PMCID: PMC6549377 DOI: 10.1186/s13567-019-0660-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 04/12/2019] [Indexed: 12/02/2022] Open
Abstract
Riemerella anatipestifer is a major pathogenic agent of duck septicemic and exudative diseases. Genetic analyses suggest that this pathogen has a novel protein secretion system, known as the “type IX secretion system” (T9SS). We previously reported that deletion of the AS87_RS08465 gene significantly reduced the bacterial virulence of the R. anatipestifer strain Yb2, but the mechanism remained unclear. The AS87_RS08465 gene is predicted to encode the gliding motility protein GldM (GldM) protein, a key component of the T9SS complex. In this study, Western blotting analysis demonstrated that R. anatipestifer GldM was localized to the cytomembrane. Further study revealed that the adhesion and invasion capacities of the mutant strain RA2281 (designated Yb2ΔgldM) in Vero cells and the bacterial loads in the blood of infected ducks were significantly reduced. RNA-Seq and PCR analyses showed that six genes were upregulated and five genes were downregulated in the mutant strain Yb2ΔgldM and that these genes were mainly involved in the secretion of proteins. Yb2ΔgldM was also found to be defective in gliding motility and protein secretion. Liquid chromatography–tandem mass spectrometry analysis revealed that nine of the proteins had a conserved T9SS C-terminal domain and were differentially secreted by Yb2ΔgldM compared to Yb2. The complementation strain cYb2ΔgldM recovered the adhesion and invasion capacities in Vero cells and the bacterial loads in the blood of infected ducks as well as the bacterial gliding motility and most protein secretion in the mutant strain Yb2ΔgldM to the levels of the wild-type strain Yb2. Taken together, these results indicate that R. anatipestifer GldM is associated with T9SS and is important in bacterial virulence.
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Affiliation(s)
- Zongchao Chen
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaolan Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Xiaomei Ren
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Wenlong Han
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Kanwar Kumar Malhi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Chan Ding
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China
| | - Shengqing Yu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai, China. .,Jiangsu Agri-animal Husbandry Vocational College, Veterinary Bio-pharmaceutical, Jiangsu Key Laboratory for High-Tech Research and Development of Veterinary Biopharmaceuticals, Taizhou, Jiangsu, China.
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15
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Naito M, Tominaga T, Shoji M, Nakayama K. PGN_0297 is an essential component of the type IX secretion system (T9SS) in Porphyromonas gingivalis: Tn-seq analysis for exhaustive identification of T9SS-related genes. Microbiol Immunol 2019; 63:11-20. [PMID: 30599082 PMCID: PMC6590471 DOI: 10.1111/1348-0421.12665] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Revised: 11/28/2018] [Accepted: 12/20/2018] [Indexed: 12/22/2022]
Abstract
The type IX secretion system (T9SS) was originally discovered in Porphyromonas gingivalis, one of the pathogenic bacteria associated with periodontal disease and is now known to be present in many members of the phylum Bacteroidetes. The T9SS secretes a number of potent virulence factors, including the highly hydrolytic proteases called gingipains, across the outer membrane in P. gingivalis. To understand the entire machinery of T9SS, an exhaustive search for T9SS‐related genes in P. gingivalis using the mariner family transposon (Tn) and Tn‐seq analysis was performed. Seven hundred and two Tn insertion sites in Tn mutants with no colony pigmentation that is associated with Lys‐gingipain (Kgp) defectiveness were determined, and it was found that the Tn was inserted in the kgp gene and 54 T9SS‐related candidate genes. Thirty‐three out of the 54 genes were already known as T9SS‐related genes. Furthermore, deletion mutant analysis of the remaining 21 genes revealed that they were not related to the T9SS. The 33 T9SS‐related genes include a gene for PGN_0297, which was found to be associated with the T9SS components PorK and PorN. A PGN_0297 gene deletion mutant was constructed, and it was found that the mutant showed no colony pigmentation, hemagglutination or gingipain activities, indicating that PGN_0297 was an essential component of the T9SS. The 33 genes did not include the six genes (gppX, omp17, porY, rfa, sigP and wzx) that were also reported as T9SS‐related genes. gppX deletion and insertion mutants were constructed, and it was found that they did not show deficiency in the T9SS.
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Affiliation(s)
- Mariko Naito
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8588, Japan
| | - Takashi Tominaga
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8588, Japan
| | - Mikio Shoji
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8588, Japan
| | - Koji Nakayama
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki City, Nagasaki, 852-8588, Japan
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16
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Abstract
ABSTRACT
Members of the phylum
Bacteroidetes
have many unique features, including gliding motility and the type IX protein secretion system (T9SS).
Bacteroidetes
gliding and T9SSs are common in, but apparently confined to, this phylum. Most, but not all, members of the phylum secrete proteins using the T9SS, and most also exhibit gliding motility. T9SSs secrete cell surface components of the gliding motility machinery and also secrete many extracellular or cell surface enzymes, adhesins, and virulence factors. The components of the T9SS are novel and are unrelated to those of other bacterial secretion systems. Proteins secreted by the T9SS rely on the Sec system to cross the cytoplasmic membrane, and they use the T9SS for delivery across the outer membrane. Secreted proteins typically have conserved C-terminal domains that target them to the T9SS. Some of the T9SS components were initially identified as proteins required for gliding motility. Gliding does not involve flagella or pili and instead relies on the rapid movement of motility adhesins, such as SprB, along the cell surface by the gliding motor. Contact of the adhesins with the substratum provides the traction that results in cell movement. SprB and other motility adhesins are delivered to the cell surface by the T9SS. Gliding and the T9SS appear to be intertwined, and components of the T9SS that span the cytoplasmic membrane may energize both gliding and protein secretion. The functions of the individual proteins in each process are the subject of ongoing investigations.
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17
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Kondo Y, Sato K, Nagano K, Nishiguchi M, Hoshino T, Fujiwara T, Nakayama K. Involvement of PorK, a component of the type IX secretion system, in Prevotella melaninogenica pathogenicity. Microbiol Immunol 2018; 62:554-566. [PMID: 30028034 DOI: 10.1111/1348-0421.12638] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 07/09/2018] [Accepted: 07/13/2018] [Indexed: 12/27/2022]
Abstract
Prevotella melaninogenica is a gram-negative anaerobic commensal bacterium that resides in the human oral cavity and is isolated as a pathogen of suppurative diseases both inside and outside the mouth. However, little is known about the pathogenic factors of P. melaninogenica. The periodontal pathogens Porphyromonas gingivalis and Tanerella forsythia secrete virulence factors such as protease and bacterial cell surface proteins via a type IX secretion system (T9SS) that are involved in pathogenicity. P. melaninogenica also possesses all known orthologs of T9SS. In this study, a P. melaninogenica GAI 07411 mutant deficient in the orthologue of the T9SS-encoding gene, porK, was constructed. Hemagglutination and biofilm formation were decreased in the porK mutant. Furthermore, following growth on skim milk-containing medium, the diameters of the halos surrounding the porK mutant were smaller than those of the wild-type strain, suggesting a decrease in secretion of proteases outside the bacterium. To investigate this in detail, culture supernatants of wild-type and porK mutant strains were purified and compared by two-dimensional electrophoresis. In the mutant strain, fewer spots were detected, indicating fewer secreted proteins. In infection experiments, the mortality rate of mice inoculated with the porK mutant strain was significantly lower than in the wild-type strain. These results suggest that P. melaninogenica secretes potent virulence factors via the T9SS that contribute to its pathogenic ability.
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Affiliation(s)
- Yoshio Kondo
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Keiko Sato
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Keiji Nagano
- Department of Microbiology, School of Dentistry, Aichi Gakuin University 1-100 Kusumoto-cho, Chikusa-ku, Nagoya, Aichi 464-8650, Japan
| | - Miyuki Nishiguchi
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Tomonori Hoshino
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Taku Fujiwara
- Department of Pediatric Dentistry, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
| | - Koji Nakayama
- Department of Microbiology and Oral Infection, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, Nagasaki 852-8588, Japan
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18
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Guo Y, Hu D, Guo J, Wang T, Xiao Y, Wang X, Li S, Liu M, Li Z, Bi D, Zhou Z. Riemerella anatipestifer Type IX Secretion System Is Required for Virulence and Gelatinase Secretion. Front Microbiol 2017; 8:2553. [PMID: 29312236 PMCID: PMC5742166 DOI: 10.3389/fmicb.2017.02553] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 12/08/2017] [Indexed: 11/16/2022] Open
Abstract
Riemerella anatipestifer (RA), a major causative agent of septicemia anserum exsudativa in domesticated ducklings, has a protein secretion system known as the type IX secretion system (T9SS). It is unknown whether the T9SS contributes to the virulence of RA through secretion of factors associated with pathogenesis. To answer this question, we constructed an RA mutant deficient in sprT, which encodes a core protein of the T9SS. Deletion of sprT yielded cells that failed to digest gelatin, an effect that was rescued via complementation by a plasmid encoding wild-type sprT. Complement-mediated killing was significantly increased in the deletion mutant, suggesting that proteins secreted by the T9SS are necessary for complement evasion in RA. Liquid chromatography-tandem mass spectrometry analysis revealed that RAYM_01812 and RAYM_04099 proteins containing a subtilisin-like serine protease domain and exhibiting extracellular gelatinase activity were secreted by the T9SS. Animal experiments demonstrated that the virulence of mutant strain ΔsprT strain was attenuated by 42,000-fold relative to wild-type RA-YM. Immunization with the ΔsprT protected ducks from challenge with RA-YM, suggesting that the former can be used as a live attenuated vaccine. These results indicate that the T9SS is functional in RA and contributes to its virulence by exporting key proteins. In addition, subtilisin-like serine proteases which are important virulence factors that interact with complement proteins may enable RA to evade immune surveillance in the avian innate immune system.
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Affiliation(s)
- Yunqing Guo
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Di Hu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Jie Guo
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Tao Wang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Yuncai Xiao
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Xiliang Wang
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Shaowen Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Mei Liu
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zili Li
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Dingren Bi
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
| | - Zutao Zhou
- College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, Huazhong Agricultural University, Wuhan, China
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19
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Fujise K, Kikuchi Y, Kokubu E, Okamoto-Shibayama K, Ishihara K. Effect of extracytoplasmic function sigma factors on autoaggregation, hemagglutination, and cell surface properties of Porphyromonas gingivalis. PLoS One 2017; 12:e0185027. [PMID: 28931045 PMCID: PMC5607195 DOI: 10.1371/journal.pone.0185027] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 09/05/2017] [Indexed: 01/05/2023] Open
Abstract
Porphyromonas gingivalis is a bacterium frequently isolated from chronic periodontal lesions and is involved in the development of chronic periodontitis. To colonize the gingival crevice, P. gingivalis has to adapt to environmental stresses. Microbial gene expression is regulated by transcription factors such as those in two-component systems and extracytoplasmic function (ECF) sigma factors. ECF sigma factors are involved in the regulation of environmental stress response genes; however, the roles of individual ECF sigma factors are largely unknown. The purpose of this study was to investigate the functions, including autoaggregation, hemagglutination, gingipain activity, susceptibility to antimicrobial agents, and surface structure formation, of P. gingivalis ECF sigma factors encoded by SigP (PGN_0274), SigCH (PGN_0319), PGN_0450, PGN_0970, and SigH (PGN_1740). Various physiological aspects of the sigP mutant were affected; autoaggregation was significantly decreased at 60 min (p < 0.001), hemagglutination activity was markedly reduced, and enzymatic activities of Kgp and Rgps were significantly decreased (p < 0.001). The other mutants also showed approximately 50% reduction in Rgps activity. Kgp activity was significantly reduced in the sigH mutant (p < 0.001). No significant differences in susceptibilities to tetracycline and ofloxacin were observed in the mutants compared to those of the wild-type strain. However, the sigP mutant displayed an increased susceptibility to ampicillin, whereas the PGN_0450 and sigH mutants showed reduced susceptibility. Transmission electron microscopy images revealed increased levels of outer membrane vesicles formed at the cell surfaces of the sigP mutant. These results indicate that SigP is important for bacterial surface-associated activities, including gingipain activity, autoaggregation, hemagglutination, vesicle formation, and antimicrobial susceptibility.
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Affiliation(s)
- Kazutaka Fujise
- Department of Microbiology, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan
| | - Yuichiro Kikuchi
- Department of Microbiology, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan.,Oral Health Science Center, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan
| | - Eitoyo Kokubu
- Department of Microbiology, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan.,Oral Health Science Center, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan
| | | | - Kazuyuki Ishihara
- Department of Microbiology, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan.,Oral Health Science Center, Tokyo Dental College, Chiyoda-ku, Tokyo, Japan
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20
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Miller DP, Hutcherson JA, Wang Y, Nowakowska ZM, Potempa J, Yoder-Himes DR, Scott DA, Whiteley M, Lamont RJ. Genes Contributing to Porphyromonas gingivalis Fitness in Abscess and Epithelial Cell Colonization Environments. Front Cell Infect Microbiol 2017; 7:378. [PMID: 28900609 PMCID: PMC5581868 DOI: 10.3389/fcimb.2017.00378] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 08/09/2017] [Indexed: 12/11/2022] Open
Abstract
Porphyromonas gingivalis is an important cause of serious periodontal diseases, and is emerging as a pathogen in several systemic conditions including some forms of cancer. Initial colonization by P. gingivalis involves interaction with gingival epithelial cells, and the organism can also access host tissues and spread haematogenously. To better understand the mechanisms underlying these properties, we utilized a highly saturated transposon insertion library of P. gingivalis, and assessed the fitness of mutants during epithelial cell colonization and survival in a murine abscess model by high-throughput sequencing (Tn-Seq). Transposon insertions in many genes previously suspected as contributing to virulence showed significant fitness defects in both screening assays. In addition, a number of genes not previously associated with P. gingivalis virulence were identified as important for fitness. We further examined fitness defects of four such genes by generating defined mutations. Genes encoding a carbamoyl phosphate synthetase, a replication-associated recombination protein, a nitrosative stress responsive HcpR transcription regulator, and RNase Z, a zinc phosphodiesterase, showed a fitness phenotype in epithelial cell colonization and in a competitive abscess infection. This study verifies the importance of several well-characterized putative virulence factors of P. gingivalis and identifies novel fitness determinants of the organism.
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Affiliation(s)
- Daniel P Miller
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Justin A Hutcherson
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Yan Wang
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Zuzanna M Nowakowska
- Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Jan Potempa
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States.,Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian UniversityKrakow, Poland.,Malopolska Centre of Biotechnology, Jagiellonian UniversityKrakow, Poland
| | | | - David A Scott
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
| | - Marvin Whiteley
- Department of Molecular Biosciences, University of Texas at AustinAustin, TX, United States
| | - Richard J Lamont
- Department of Oral Immunology and Infectious Diseases, University of LouisvilleLouisville, KY, United States
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21
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Veith PD, Glew MD, Gorasia DG, Reynolds EC. Type IX secretion: the generation of bacterial cell surface coatings involved in virulence, gliding motility and the degradation of complex biopolymers. Mol Microbiol 2017; 106:35-53. [DOI: 10.1111/mmi.13752] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2017] [Indexed: 12/15/2022]
Affiliation(s)
- Paul D. Veith
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
| | - Michelle D. Glew
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
| | - Dhana G. Gorasia
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
| | - Eric C. Reynolds
- Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute; The University of Melbourne; Melbourne Australia
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22
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Nakayama M, Ohara N. Molecular mechanisms of Porphyromonas gingivalis-host cell interaction on periodontal diseases. JAPANESE DENTAL SCIENCE REVIEW 2017; 53:134-140. [PMID: 29201258 PMCID: PMC5703693 DOI: 10.1016/j.jdsr.2017.06.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 02/03/2017] [Accepted: 06/28/2017] [Indexed: 12/31/2022] Open
Abstract
Porphyromonas gingivalis (P. gingivalis) is a major oral pathogen and associated with periodontal diseases including periodontitis and alveolar bone loss. In this review, we indicate that two virulence factors, which are hemoglobin receptor protein (HbR) and cysteine proteases “gingipains”, expressed by P. gingivalis have novel functions on the pathogenicity of P. gingivalis. P. gingivalis produces three types of gingipains and concomitantly several adhesin domains. Among the adhesin domains, hemoglobin receptor protein (HbR), also called HGP15, has the function of induction of interleukin-8 (IL-8) expression in human gingival epithelial cells, indicating the possibility that HbR is associated with P. gingivalis-induced periodontal inflammation. On bacteria-host cells contact, P. gingivalis induces cellular signaling alteration in host cells. Phosphatidylinositol 3-kinase (PI3K) and Akt are well known to play a pivotal role in various cellular physiological functions including cell survival and glucose metabolism in mammalian cells. Recently, we demonstrated that gingipains attenuate the activity of PI3K and Akt, which might have a causal influence on periodontal diseases by chronic infection to the host cells from the speculation of molecular analysis. In this review, we discuss new molecular and biological characterization of the virulence factors from P. gingivalis.
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Affiliation(s)
- Masaaki Nakayama
- Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.,The Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama 700-8558, Japan
| | - Naoya Ohara
- Department of Oral Microbiology, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.,The Advanced Research Center for Oral and Craniofacial Sciences, Dental School, Okayama University, Okayama 700-8558, Japan
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23
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Lasica AM, Ksiazek M, Madej M, Potempa J. The Type IX Secretion System (T9SS): Highlights and Recent Insights into Its Structure and Function. Front Cell Infect Microbiol 2017. [PMID: 28603700 DOI: 10.3389/fcimb.2017.00215.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Protein secretion systems are vital for prokaryotic life, as they enable bacteria to acquire nutrients, communicate with other species, defend against biological and chemical agents, and facilitate disease through the delivery of virulence factors. In this review, we will focus on the recently discovered type IX secretion system (T9SS), a complex translocon found only in some species of the Bacteroidetes phylum. T9SS plays two roles, depending on the lifestyle of the bacteria. It provides either a means of movement (called gliding motility) for peace-loving environmental bacteria or a weapon for pathogens. The best-studied members of these two groups are Flavobacterium johnsoniae, a commensal microorganism often found in water and soil, and Porphyromonas gingivalis, a human oral pathogen that is a major causative agent of periodontitis. In P. gingivalis and some other periodontopathogens, T9SS translocates proteins, especially virulence factors, across the outer membrane (OM). Proteins destined for secretion bear a conserved C-terminal domain (CTD) that directs the cargo to the OM translocon. At least 18 proteins are involved in this still enigmatic process, with some engaged in the post-translational modification of T9SS cargo proteins. Upon translocation across the OM, the CTD is removed by a protease with sortase-like activity and an anionic LPS is attached to the newly formed C-terminus. As a result, a cargo protein could be secreted into the extracellular milieu or covalently attached to the bacterial surface. T9SS is regulated by a two-component system; however, the precise environmental signal that triggers it has not been identified. Exploring unknown systems contributing to bacterial virulence is exciting, as it may eventually lead to new therapeutic strategies. During the past decade, the major components of T9SS were identified, as well as hints suggesting the possible mechanism of action. In addition, the list of characterized cargo proteins is constantly growing. The actual structure of the translocon, situated in the OM of bacteria, remains the least explored area; however, new technical approaches and increasing scientific attention have resulted in a growing body of data. Therefore, we present a compact up-to-date review of this topic.
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Affiliation(s)
- Anna M Lasica
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of DentistryLouisville, KY, United States.,Department of Bacterial Genetics, Faculty of Biology, Institute of Microbiology, University of WarsawWarsaw, Poland
| | - Miroslaw Ksiazek
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of DentistryLouisville, KY, United States.,Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Mariusz Madej
- Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Jan Potempa
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of DentistryLouisville, KY, United States.,Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian UniversityKrakow, Poland
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Lasica AM, Ksiazek M, Madej M, Potempa J. The Type IX Secretion System (T9SS): Highlights and Recent Insights into Its Structure and Function. Front Cell Infect Microbiol 2017; 7:215. [PMID: 28603700 PMCID: PMC5445135 DOI: 10.3389/fcimb.2017.00215] [Citation(s) in RCA: 174] [Impact Index Per Article: 24.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/11/2017] [Indexed: 12/11/2022] Open
Abstract
Protein secretion systems are vital for prokaryotic life, as they enable bacteria to acquire nutrients, communicate with other species, defend against biological and chemical agents, and facilitate disease through the delivery of virulence factors. In this review, we will focus on the recently discovered type IX secretion system (T9SS), a complex translocon found only in some species of the Bacteroidetes phylum. T9SS plays two roles, depending on the lifestyle of the bacteria. It provides either a means of movement (called gliding motility) for peace-loving environmental bacteria or a weapon for pathogens. The best-studied members of these two groups are Flavobacterium johnsoniae, a commensal microorganism often found in water and soil, and Porphyromonas gingivalis, a human oral pathogen that is a major causative agent of periodontitis. In P. gingivalis and some other periodontopathogens, T9SS translocates proteins, especially virulence factors, across the outer membrane (OM). Proteins destined for secretion bear a conserved C-terminal domain (CTD) that directs the cargo to the OM translocon. At least 18 proteins are involved in this still enigmatic process, with some engaged in the post-translational modification of T9SS cargo proteins. Upon translocation across the OM, the CTD is removed by a protease with sortase-like activity and an anionic LPS is attached to the newly formed C-terminus. As a result, a cargo protein could be secreted into the extracellular milieu or covalently attached to the bacterial surface. T9SS is regulated by a two-component system; however, the precise environmental signal that triggers it has not been identified. Exploring unknown systems contributing to bacterial virulence is exciting, as it may eventually lead to new therapeutic strategies. During the past decade, the major components of T9SS were identified, as well as hints suggesting the possible mechanism of action. In addition, the list of characterized cargo proteins is constantly growing. The actual structure of the translocon, situated in the OM of bacteria, remains the least explored area; however, new technical approaches and increasing scientific attention have resulted in a growing body of data. Therefore, we present a compact up-to-date review of this topic.
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Affiliation(s)
- Anna M Lasica
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of DentistryLouisville, KY, United States.,Department of Bacterial Genetics, Faculty of Biology, Institute of Microbiology, University of WarsawWarsaw, Poland
| | - Miroslaw Ksiazek
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of DentistryLouisville, KY, United States.,Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Mariusz Madej
- Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian UniversityKrakow, Poland
| | - Jan Potempa
- Department of Oral Immunology and Infectious Diseases, University of Louisville School of DentistryLouisville, KY, United States.,Department of Microbiology, Faculty of Biochemistry, Biophysics, and Biotechnology, Jagiellonian UniversityKrakow, Poland
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25
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Vincent MS, Canestrari MJ, Leone P, Stathopulos J, Ize B, Zoued A, Cambillau C, Kellenberger C, Roussel A, Cascales E. Characterization of the Porphyromonas gingivalis Type IX Secretion Trans-envelope PorKLMNP Core Complex. J Biol Chem 2017; 292:3252-3261. [PMID: 28057754 DOI: 10.1074/jbc.m116.765081] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 12/21/2016] [Indexed: 02/03/2023] Open
Abstract
The transport of proteins at the cell surface of Bacteroidetes depends on a secretory apparatus known as type IX secretion system (T9SS). This machine is responsible for the cell surface exposition of various proteins, such as adhesins, required for gliding motility in Flavobacterium, S-layer components in Tannerella forsythia, and tooth tissue-degrading enzymes in the oral pathogen Porphyromonas gingivalis Although a number of subunits of the T9SS have been identified, we lack details on the architecture of this secretion apparatus. Here we provide evidence that five of the genes encoding the core complex of the T9SS are co-transcribed and that the gene products are distributed in the cell envelope. Protein-protein interaction studies then revealed that these proteins oligomerize and interact through a dense network of contacts.
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Affiliation(s)
- Maxence S Vincent
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UMR 7255, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Mickaël J Canestrari
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UMR 7255, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Philippe Leone
- Architecture et Fonction des Macromolécules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France; Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France
| | - Julien Stathopulos
- Architecture et Fonction des Macromolécules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France; Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France
| | - Bérengère Ize
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UMR 7255, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Abdelrahim Zoued
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UMR 7255, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France
| | - Christian Cambillau
- Architecture et Fonction des Macromolécules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France; Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France
| | - Christine Kellenberger
- Architecture et Fonction des Macromolécules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France; Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France
| | - Alain Roussel
- Architecture et Fonction des Macromolécules Biologiques, CNRS, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France; Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, UMR 7257, Campus de Luminy, Case 932, 13288 Marseille Cedex 09, France
| | - Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, UMR 7255, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - CNRS, 31 Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France.
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26
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Structural and functional probing of PorZ, an essential bacterial surface component of the type-IX secretion system of human oral-microbiomic Porphyromonas gingivalis. Sci Rep 2016; 6:37708. [PMID: 27883039 PMCID: PMC5121618 DOI: 10.1038/srep37708] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 11/03/2016] [Indexed: 12/30/2022] Open
Abstract
Porphyromonas gingivalis is a member of the human oral microbiome abundant in dysbiosis and implicated in the pathogenesis of periodontal (gum) disease. It employs a newly described type-IX secretion system (T9SS) for secretion of virulence factors. Cargo proteins destined for secretion through T9SS carry a recognition signal in the conserved C-terminal domain (CTD), which is removed by sortase PorU during translocation. Here, we identified a novel component of T9SS, PorZ, which is essential for surface exposure of PorU and posttranslational modification of T9SS cargo proteins. These include maturation of enzyme precursors, CTD removal and attachment of anionic lipopolysaccharide for anchorage in the outer membrane. The crystal structure of PorZ revealed two β-propeller domains and a C-terminal β-sandwich domain, which conforms to the canonical CTD architecture. We further documented that PorZ is itself transported to the cell surface via T9SS as a full-length protein with its CTD intact, independently of the presence or activity of PorU. Taken together, our results shed light on the architecture and possible function of a novel component of the T9SS. Knowledge of how T9SS operates will contribute to our understanding of protein secretion as part of host-microbiome interactions by dysbiotic members of the human oral cavity.
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Vincent MS, Durand E, Cascales E. The PorX Response Regulator of the Porphyromonas gingivalis PorXY Two-Component System Does Not Directly Regulate the Type IX Secretion Genes but Binds the PorL Subunit. Front Cell Infect Microbiol 2016; 6:96. [PMID: 27630829 PMCID: PMC5005315 DOI: 10.3389/fcimb.2016.00096] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 08/19/2016] [Indexed: 12/27/2022] Open
Abstract
The Type IX secretion system (T9SS) is a versatile multi-protein complex restricted to bacteria of the Bacteriodetes phylum and responsible for the secretion or cell surface exposition of diverse proteins that participate to S-layer formation, gliding motility or pathogenesis. The T9SS is poorly characterized but a number of proteins involved in the assembly of the secretion apparatus in the oral pathogen Porphyromonas gingivalis have been identified based on genome substractive analyses. Among these proteins, PorY, and PorX encode typical two-component system (TCS) sensor and CheY-like response regulator respectively. Although the porX and porY genes do not localize at the same genetic locus, it has been proposed that PorXY form a bona fide TCS. Deletion of porX in P. gingivalis causes a slight decrease of the expression of a number of other T9SS genes, including sov, porT, porP, porK, porL, porM, porN, and porY. Here, we show that PorX and the soluble cytoplasmic domain of PorY interact. Using electrophoretic mobility shift, DNA-protein co-purification and heterologous host expression assays, we demonstrate that PorX does not bind T9SS gene promoters and does not directly regulate expression of the T9SS genes. Finally, we show that PorX interacts with the cytoplasmic domain of PorL, a component of the T9SS membrane core complex and propose that the CheY-like PorX protein might be involved in the dynamics of the T9SS.
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Affiliation(s)
- Maxence S Vincent
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - Centre National de la Recherche Scientifique (UMR7255) Marseille, France
| | - Eric Durand
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - Centre National de la Recherche Scientifique (UMR7255) Marseille, France
| | - Eric Cascales
- Laboratoire d'Ingénierie des Systèmes Macromoléculaires, Institut de Microbiologie de la Méditerranée, Aix-Marseille Université - Centre National de la Recherche Scientifique (UMR7255) Marseille, France
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