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Lin MH, Liu CC, Lu CW, Shu JC. Staphylococcus aureus foldase PrsA contributes to the folding and secretion of protein A. BMC Microbiol 2024; 24:108. [PMID: 38566014 PMCID: PMC10986000 DOI: 10.1186/s12866-024-03268-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 03/20/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Staphylococcus aureus secretes a variety of proteins including virulence factors that cause diseases. PrsA, encoded by many Gram-positive bacteria, is a membrane-anchored lipoprotein that functions as a foldase to assist in post-translocational folding and helps maintain the stability of secreted proteins. Our earlier proteomic studies found that PrsA is required for the secretion of protein A, an immunoglobulin-binding protein that contributes to host immune evasion. This study aims to investigate how PrsA influences protein A secretion. RESULTS We found that in comparison with the parental strain HG001, the prsA-deletion mutant HG001ΔprsA secreted less protein A. Deleting prsA also decreased the stability of exported protein A. Pulldown assays indicated that PrsA interacts with protein A in vivo. The domains in PrsA that interact with protein A are mapped to both the N- and C-terminal regions (NC domains). Additionally, the NC domains are essential for promoting PrsA dimerization. Furthermore, an immunoglobulin-binding assay revealed that, compared to the parental strain HG001, fewer immunoglobulins bound to the surface of the mutant strain HG001ΔprsA. CONCLUSIONS This study demonstrates that PrsA is critical for the folding and secretion of protein A. The information derived from this study provides a better understanding of virulent protein export pathways that are crucial to the pathogenicity of S. aureus.
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Affiliation(s)
- Mei-Hui Lin
- Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Tao-Yuan, 333, Taiwan.
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Tao-Yuan, 333, Taiwan.
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao- Yuan, 333, Taiwan.
| | - Chao-Chin Liu
- Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Tao-Yuan, 333, Taiwan
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao- Yuan, 333, Taiwan
| | - Chiao-Wen Lu
- Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Tao-Yuan, 333, Taiwan
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Tao-Yuan, 333, Taiwan
| | - Jwu-Ching Shu
- Graduate Institute of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Tao-Yuan, 333, Taiwan.
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Tao-Yuan, 333, Taiwan.
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Tao- Yuan, 333, Taiwan.
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2
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George JL, Agbavor C, Cabo LF, Cahoon LA. Streptococcus pneumoniae secretion chaperones PrsA, SlrA, and HtrA are required for competence, antibiotic resistance, colonization, and invasive disease. Infect Immun 2024; 92:e0049023. [PMID: 38226817 PMCID: PMC10863415 DOI: 10.1128/iai.00490-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 12/19/2023] [Indexed: 01/17/2024] Open
Abstract
Streptococcus pneumoniae is a Gram-positive bacterium and a significant health threat with the populations most at risk being children, the elderly, and the immuno-compromised. To colonize and transition into an invasive infectious organism, S. pneumoniae secretes virulence factors that are translocated across the bacterial membrane and destined for surface exposure, attachment to the cell wall, or secretion into the host. The surface exposed protein chaperones PrsA, SlrA, and HtrA facilitate S. pneumoniae protein secretion; however, the distinct roles contributed by each of these secretion chaperones have not been well defined. Tandem Mass-Tagged Mass Spectrometry and virulence, adhesion, competence, and cell wall integrity assays were used to interrogate the individual and collective contributions of PrsA, SlrA, and HtrA to multiple aspects of S. pneumoniae physiology and virulence. PrsA, SlrA, and HtrA were found to play critical roles in S. pneumoniae host cell infection and competence, and the absence of each of these secretion chaperones significantly altered the S. pneumoniae secretome in distinct ways. PrsA and SlrA were additionally found to contribute to cell wall assembly and resistance to cell wall-active antimicrobials and were important for enabling S. pneumoniae host cell adhesion during colonization and invasive infection. These findings serve to further illustrate the pivotal contributions of PrsA, SlrA, and HtrA to S. pneumoniae protein secretion and virulence.
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Affiliation(s)
- Jada L. George
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Charles Agbavor
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Leah F. Cabo
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Laty A. Cahoon
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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3
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Jiang X, Yu G, Zhu L, Siddique A, Zhan D, Zhou L, Yue M. Flanking N- and C-terminal domains of PrsA in Streptococcus suis type 2 are crucial for inducing cell death independent of TLR2 recognition. Virulence 2023; 14:2249779. [PMID: 37641974 PMCID: PMC10467536 DOI: 10.1080/21505594.2023.2249779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 06/12/2023] [Accepted: 07/25/2023] [Indexed: 08/31/2023] Open
Abstract
Streptococcus suis type 2 (SS2), a major emerging/re-emerging zoonotic pathogen found in humans and pigs, can cause severe clinical infections, and pose public health issues. Our previous studies recognized peptidyl-prolyl isomerase (PrsA) as a critical virulence factor promoting SS2 pathogenicity. PrsA contributed to cell death and operated as a pro-inflammatory effector. However, the molecular pathways through which PrsA contributes to cell death are poorly understood. Here in this study, we prepared the recombinant PrsA protein and found that pyroptosis and necroptosis were involved in cell death stimulated by PrsA. Specific pyroptosis and necroptosis signalling inhibitors could significantly alleviate the fatal effect. Cleaved caspase-1 and IL-1β in pyroptosis with phosphorylated MLKL proteins in necroptosis pathways, respectively, were activated after PrsA stimulation. Truncated protein fragments of enzymatic PPIase domain (PPI), N-terminal (NP), and C-terminal (PC) domains fused with PPIase, were expressed and purified. PrsA flanking N- or C-terminal but not enzymatic PPIase domain was found to be critical for PrsA function in inducing cell death and inflammation. Additionally, PrsA protein could be anchored on the cell surface to interact with host cells. However, Toll-like receptor 2 (TLR2) was not implicated in cell death and recognition of PrsA. PAMPs of PrsA could not promote TLR2 activation, and no rescued phenotypes of death were shown in cells blocking of TLR2 receptor or signal-transducing adaptor of MyD88. Overall, these data, for the first time, advanced our perspective on PrsA function and elucidated that PrsA-induced cell death requires its flanking N- or C-terminal domain but is dispensable for recognizing TLR2. Further efforts are still needed to explore the precise molecular mechanisms of PrsA-inducing cell death and, therefore, contribution to SS2 pathogenicity.
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Affiliation(s)
- Xiaowu Jiang
- College of Medicine, Yichun University, Yichun, Jiangxi, China
- Jiangxi Provincial Key Laboratory of Active Component of Natural Drugs, Poster-Doctoral Research Center, Yichun, Jiangxi, China
| | - Guijun Yu
- College of Medicine, Yichun University, Yichun, Jiangxi, China
| | - Lexin Zhu
- College of Medicine, Yichun University, Yichun, Jiangxi, China
| | - Abubakar Siddique
- Hainan Institute of Zhejiang University, Sanya, China
- Atta Ur Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Dongbo Zhan
- College of Medicine, Yichun University, Yichun, Jiangxi, China
| | - Linhua Zhou
- College of Medicine, Yichun University, Yichun, Jiangxi, China
| | - Min Yue
- Hainan Institute of Zhejiang University, Sanya, China
- Department of Veterinary Medicine, Institute of Preventive Veterinary Sciences, College of Animal Sciences, Zhejiang University, Hangzhou, China
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4
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Hsu CC, Hsu RB, Oon XH, Chen YT, Chen JW, Hsu CH, Kuo YM, Shih YH, Chia JS, Jung CJ. Streptococcus mutans PrsA mediates AtlA secretion contributing to extracellular DNA release and biofilm formation in the pathogenesis of infective endocarditis. Virulence 2022; 13:1379-1392. [PMID: 35876630 PMCID: PMC9377233 DOI: 10.1080/21505594.2022.2105351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The role of secretion chaperone-regulated virulence proteins in the pathogenesis of infective endocarditis (IE) induced by viridans streptococci such as Streptococcus mutans is unclear. In this study, we investigated the contribution of the foldase protein PrsA, a putative parvulin-type peptidyl-prolyl isomerase, to the pathogenesis of S. mutans-induced IE. We found that a prsA-deficient strain had reduced virulence in terms of formation of vegetation on damaged heart valves, as well as reduced autolysis activity, eDNA release and biofilm formation capacity. The secretion and surface exposure of AtlA in vitro was reduced in the prsA-deficient mutant strain, and complementation of recombinant AtlA in the culture medium restored a wild type biofilm phenotype of the prsA-deficient mutant strain. This result suggests that secretion and surface localization of AtlA is regulated by PrsA during biofilm formation. Together, these results demonstrate that S. mutans PrsA could regulate AtlA-mediated eDNA release to contribute to biofilm formation in the pathogenesis of IE.
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Affiliation(s)
- Chih-Chieh Hsu
- Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Oral Biology, School of Dentistry, National Taiwan University, Taipei, Taiwan
| | - Ron-Bin Hsu
- Department of Surgery, Division of Cardiovascular Surgery, National Taiwan University Hospital , College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Xoong-Harng Oon
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan.,Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ya-Tang Chen
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan
| | - Jeng-Wei Chen
- Department of Surgery, Division of Cardiovascular Surgery, National Taiwan University Hospital , College of Medicine, National Taiwan University, Taipei, Taiwan.,Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Che-Hao Hsu
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan
| | - Yu-Min Kuo
- Graduate Institute of Clinical Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan.,Division of Allergy, Immunology, and Rheumatology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Yi-Hsien Shih
- Department of Dermatology, Taipei Medical University-Shuang Ho Hospital, New Taipei City, Taiwan.,Department of Dermatology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jean-San Chia
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan.,Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chiau-Jing Jung
- Graduate Institute of Medical Sciences, College of Medicine, Taipei medical University, Taipei, Taiwan.,Department of Microbiology and Immunology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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5
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Wu ZY, Campeau A, Liu CH, Gonzalez DJ, Yamaguchi M, Kawabata S, Lu CH, Lai CY, Chiu HC, Chang YC. Unique virulence role of post-translocational chaperone PrsA in shaping Streptococcus pyogenes secretome. Virulence 2021; 12:2633-2647. [PMID: 34592883 PMCID: PMC8489961 DOI: 10.1080/21505594.2021.1982501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pyogenes (group A Streptococcus, GAS) is a strict human pathogen causing a broad spectrum of diseases and a variety of autoimmune sequelae. The pathogenesis of GAS infection mostly relies on the production of an extensive network of cell wall-associated and secreted virulence proteins, such as adhesins, toxins, and exoenzymes. PrsA, the only extracellular parvulin-type peptidyl-prolyl isomerase expressed ubiquitously in Gram-positive bacteria, has been suggested to assist the folding and maturation of newly exported proteins to acquire their native conformation and activity. Two PrsA proteins, PrsA1 and PrsA2, have been identified in GAS, but the respective contribution of each PrsA in GAS pathogenesis remains largely unknown. By combining comparative proteomic and phenotypic analysis approaches, we demonstrate that both PrsA isoforms are required to maintain GAS proteome homeostasis and virulence-associated traits in a unique and overlapping manner. The inactivation of both PrsA in GAS caused remarkable impairment in biofilm formation, host adherence, infection-induced cytotoxicity, and in vivo virulence in a murine soft tissue infection model. The concordance of proteomic and phenotypic data clearly features the essential role of PrsA in GAS full virulence.
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Affiliation(s)
- Zhao-Yi Wu
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Anaamika Campeau
- Department of Pharmacology and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, USA
| | - Chao-Hsien Liu
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - David J Gonzalez
- Department of Pharmacology and Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, CA, USA
| | - Masaya Yamaguchi
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Shigetada Kawabata
- Department of Oral and Molecular Microbiology, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Chieh-Hsien Lu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Chian-Yu Lai
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Hao-Chieh Chiu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Yung-Chi Chang
- Graduate Institute of Microbiology, College of Medicine, National Taiwan University, Taipei, Taiwan
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6
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Quesada-Ganuza A, Antelo-Varela M, Mouritzen JC, Bartel J, Becher D, Gjermansen M, Hallin PF, Appel KF, Kilstrup M, Rasmussen MD, Nielsen AK. Identification and optimization of PrsA in Bacillus subtilis for improved yield of amylase. Microb Cell Fact 2019; 18:158. [PMID: 31530286 PMCID: PMC6749698 DOI: 10.1186/s12934-019-1203-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 09/03/2019] [Indexed: 12/19/2022] Open
Abstract
Background PrsA is an extracytoplasmic folding catalyst essential in Bacillus subtilis. Overexpression of the native PrsA from B. subtilis has repeatedly lead to increased amylase yields. Nevertheless, little is known about how the overexpression of heterologous PrsAs can affect amylase secretion. Results In this study, the final yield of five extracellular alpha-amylases was increased by heterologous PrsA co-expression up to 2.5 fold. The effect of the overexpression of heterologous PrsAs on alpha-amylase secretion is specific to the co-expressed alpha-amylase. Co-expression of a heterologous PrsA can significantly reduce the secretion stress response. Engineering of the B. licheniformis PrsA lead to a further increase in amylase secretion and reduced secretion stress. Conclusions In this work we show how heterologous PrsA overexpression can give a better result on heterologous amylase secretion than the native PrsA, and that PrsA homologs show a variety of specificity towards different alpha-amylases. We also demonstrate that on top of increasing amylase yield, a good PrsA–amylase pairing can lower the secretion stress response of B. subtilis. Finally, we present a new recombinant PrsA variant with increased performance in both supporting amylase secretion and lowering secretion stress.
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Affiliation(s)
- Ane Quesada-Ganuza
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark
| | - Minia Antelo-Varela
- Institute for Microbiology, Department of Microbial Proteomics, Ernst-Moritz-Arndt-University Greifswald, F.- Hausdorff-Str. 8, 17489, Greifswald, Germany
| | - Jeppe C Mouritzen
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark
| | - Jürgen Bartel
- Institute for Microbiology, Department of Microbial Proteomics, Ernst-Moritz-Arndt-University Greifswald, F.- Hausdorff-Str. 8, 17489, Greifswald, Germany
| | - Dörte Becher
- Institute for Microbiology, Department of Microbial Proteomics, Ernst-Moritz-Arndt-University Greifswald, F.- Hausdorff-Str. 8, 17489, Greifswald, Germany
| | - Morten Gjermansen
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark
| | - Peter F Hallin
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark
| | - Karen F Appel
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark
| | - Mogens Kilstrup
- Technical University of Denmark, Søltofts Plads, Building 221, Room 204, 2800, Lyngby, Denmark
| | - Michael D Rasmussen
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark
| | - Allan K Nielsen
- Research and Technology, Novozymes A/S, Krogshoejvej 36, 2880, Basgvaerd, Denmark.
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7
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Keogh RA, Zapf RL, Trzeciak E, Null GG, Wiemels RE, Carroll RK. Novel Regulation of Alpha-Toxin and the Phenol-Soluble Modulins by Peptidyl-Prolyl cis/trans Isomerase Enzymes in Staphylococcus aureus. Toxins (Basel) 2019; 11:toxins11060343. [PMID: 31208155 PMCID: PMC6628628 DOI: 10.3390/toxins11060343] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/10/2019] [Accepted: 06/12/2019] [Indexed: 02/07/2023] Open
Abstract
Peptidyl-prolyl cis/trans isomerases (PPIases) are enzymes that catalyze the cis-to-trans isomerization around proline bonds, allowing proteins to fold into their correct confirmation. Previously, we identified two PPIase enzymes in Staphylococcus aureus (PpiB and PrsA) that are involved in the regulation of virulence determinants and have shown that PpiB contributes to S. aureus virulence in a murine abscess model of infection. Here, we further examine the role of these PPIases in S. aureus virulence and, in particular, their regulation of hemolytic toxins. Using murine abscess and systemic models of infection, we show that a ppiB mutant in a USA300 background is attenuated for virulence but that a prsA mutant is not. Deletion of the ppiB gene leads to decreased bacterial survival in macrophages and nasal epithelial cells, while there is no significant difference when prsA is deleted. Analysis of culture supernatants reveals that a ppiB mutant strain has reduced levels of the phenol-soluble modulins and that both ppiB and prsA mutants have reduced alpha-toxin activity. Finally, we perform immunoprecipitation to identify cellular targets of PpiB and PrsA. Results suggest a novel role for PpiB in S. aureus protein secretion. Collectively, our results demonstrate that PpiB and PrsA influence S. aureus toxins via distinct mechanisms, and that PpiB but not PrsA contributes to disease.
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Affiliation(s)
- Rebecca A Keogh
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Rachel L Zapf
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Emily Trzeciak
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Gillian G Null
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Richard E Wiemels
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
| | - Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA.
- The Infectious and Tropical Disease Institute, Ohio University, Athens, OH 45701, USA.
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8
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Renzoni A, Kelley WL, Rosato RR, Martinez MP, Roch M, Fatouraei M, Haeusser DP, Margolin W, Fenn S, Turner RD, Foster SJ, Rosato AE. Molecular Bases Determining Daptomycin Resistance-Mediated Resensitization to β-Lactams (Seesaw Effect) in Methicillin-Resistant Staphylococcus aureus. Antimicrob Agents Chemother 2017; 61:e01634-16. [PMID: 27795377 DOI: 10.1128/AAC.01634-16] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/12/2016] [Indexed: 12/18/2022] Open
Abstract
Antimicrobial resistance is recognized as one of the principal threats to public health worldwide, yet the problem is increasing. Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) strains are among the most difficult to treat in clinical settings due to the resistance of MRSA to nearly all available antibiotics. The cyclic anionic lipopeptide antibiotic daptomycin (DAP) is the clinical mainstay of anti-MRSA therapy. The decreased susceptibility to DAP (DAP resistance [DAPr]) reported in MRSA is frequently accompanied by a paradoxical decrease in β-lactam resistance, a process known as the "seesaw effect." Despite the observed discordance in resistance phenotypes, the combination of DAP and β-lactams has been proven to be clinically effective for the prevention and treatment of infections due to DAPr MRSA strains. However, the mechanisms underlying the interactions between DAP and β-lactams are largely unknown. In the study described here, we studied the role of mprF with DAP-induced mutations in β-lactam sensitization and its involvement in the effective killing by the DAP-oxacillin (OXA) combination. DAP-OXA-mediated effects resulted in cell wall perturbations, including changes in peptidoglycan insertion, penicillin-binding protein 2 (PBP 2) delocalization, and reduced membrane amounts of PBP 2a, despite the increased transcription of mecA through mec regulatory elements. We have found that the VraSR sensor-regulator is a key component of DAP resistance, triggering mutated mprF-mediated cell membrane (CM) modifications that result in impairment of PrsA location and chaperone functions, both of which are essential for PBP 2a maturation, the key determinant of β-lactam resistance. These observations provide for the first time evidence that synergistic effects between DAP and β-lactams involve PrsA posttranscriptional regulation of CM-associated PBP 2a.
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9
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Wiemels RE, Cech SM, Meyer NM, Burke CA, Weiss A, Parks AR, Shaw LN, Carroll RK. An Intracellular Peptidyl-Prolyl cis/trans Isomerase Is Required for Folding and Activity of the Staphylococcus aureus Secreted Virulence Factor Nuclease. J Bacteriol 2017; 199:e00453-16. [PMID: 27795319 DOI: 10.1128/JB.00453-16] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 10/04/2016] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus is an important human pathogen that relies on a large repertoire of secreted and cell wall-associated proteins for pathogenesis. Consequently, the ability of the organism to cause disease is absolutely dependent on its ability to synthesize and successfully secrete these proteins. In this study, we investigate the role of peptidyl-prolyl cis/trans isomerases (PPIases) on the activity of the S. aureus secreted virulence factor nuclease (Nuc). We identify a staphylococcal cyclophilin-type PPIase (PpiB) that is required for optimal activity of Nuc. Disruption of ppiB results in decreased nuclease activity in culture supernatants; however, the levels of Nuc protein are not altered, suggesting that the decrease in activity results from misfolding of Nuc in the absence of PpiB. We go on to demonstrate that PpiB exhibits PPIase activity in vitro, is localized to the bacterial cytosol, and directly interacts with Nuc in vitro to accelerate the rate of Nuc refolding. Finally, we demonstrate an additional role for PpiB in S. aureus hemolysis and demonstrate that the S. aureus parvulin-type PPIase PrsA also plays a role in the activity of secreted virulence factors. The deletion of prsA leads to a decrease in secreted protease and phospholipase activity, similar to that observed in other Gram-positive pathogens. Together, these results demonstrate, for the first time to our knowledge, that PPIases play an important role in the secretion of virulence factors in S. aureus IMPORTANCE: Staphylococcus aureus is a highly dangerous bacterial pathogen capable of causing a variety of infections throughout the human body. The ability of S. aureus to cause disease is largely due to an extensive repertoire of secreted and cell wall-associated proteins, including adhesins, toxins, exoenzymes, and superantigens. These virulence factors, once produced, are typically transported across the cell membrane by the secretory (Sec) system in a denatured state. Consequently, once outside the cell, they must refold into their active form. This step often requires the assistance of bacterial folding proteins, such as PPIases. In this work, we investigate the role of PPIases in S. aureus and uncover a cyclophilin-type enzyme that assists in the folding/refolding of staphylococcal nuclease.
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10
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Jiang X, Yang Y, Zhou J, Zhu L, Gu Y, Zhang X, Li X, Fang W. Roles of the Putative Type IV-like Secretion System Key Component VirD4 and PrsA in Pathogenesis of Streptococcus suis Type 2. Front Cell Infect Microbiol 2016; 6:172. [PMID: 27995095 PMCID: PMC5133265 DOI: 10.3389/fcimb.2016.00172] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 11/17/2016] [Indexed: 12/19/2022] Open
Abstract
Streptococcus suis type 2 (SS2) is a zoonotic pathogen causing septic infection, meningitis and pneumonia in pigs and humans. SS2 may cause streptococcal toxic shock syndrome (STSS) probably due to excessive release of inflammatory cytokines. A previous study indicated that the virD4 gene in the putative type IV-like secretion system (T4SS) within the 89K pathogenicity island specific for recent epidemic strains contributed to the development of STSS. However, the functional basis of VirD4 in STSS remains unclear. Here we show that deletion of virD4 led to reduced virulence as shown by about 65% higher LD50, lower bacterial load in liver and brain, and lower level of expression of inflammatory cytokines in mice and cell lines than its parent strain. The ΔVirD4 mutant was more easily phagocytosed, suggesting its role as an anti-phagocytic factor. Oxidative stress that mimic bacterial exposure to respiratory burst of phagocytes upregulated expression of virD4. Proteomic analysis identified 10 secreted proteins of significant differences between the parent and mutant strains under oxidative stress, including PrsA, a peptidyl-prolyl isomerase. The SS2 PrsA expressed in E. coli caused a dose-dependent cell death and increased expression of proinflammatory IL-1β, IL-6 and TNF-α in murine macrophage cells. Our data provide novel insights into the contribution of the VirD4 factor to STSS pathogenesis, possibly via its anti-phagocytic activity, upregulation of its expression upon oxidative stress and its involvement in increased secretion of PrsA as a cell death inducer and proinflammatory effector.
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Affiliation(s)
- Xiaowu Jiang
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Yunkai Yang
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Jingjing Zhou
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Lexin Zhu
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Yuanxing Gu
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Xiaoyan Zhang
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Xiaoliang Li
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
| | - Weihuan Fang
- Zhejiang University Institute of Preventive Veterinary Medicine, and Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine Zhejiang, China
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Cahoon LA, Freitag NE. Listeria monocytogenes virulence factor secretion: don't leave the cell without a chaperone. Front Cell Infect Microbiol 2014; 4:13. [PMID: 24575392 PMCID: PMC3921577 DOI: 10.3389/fcimb.2014.00013] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 01/25/2014] [Indexed: 11/13/2022] Open
Abstract
In Gram-positive bacteria, the secretion of proteins requires translocation of polypeptides across the bacterial membrane into the highly charged environment of the membrane-cell wall interface. Here, proteins must be folded and often further delivered across the matrix of the cell wall. While many aspects of protein secretion have been well studied in Gram-negative bacteria which possess both an inner and outer membrane, generally less attention has been given to the mechanics of protein secretion across the single cell membrane of Gram-positive bacteria. In this review, we focus on the role of a post-translocation secretion chaperone in Listeria monocytogenes known as PrsA2, and compare what is known regarding PrsA2 with PrsA homologs in other Gram-positive bacteria. PrsA2 is a member of a family of membrane-associated lipoproteins that contribute to the folding and stability of secreted proteins as they cross the bacterial membrane. PrsA2 contributes to the integrity of the L. monocytogenes cell wall as well as swimming motility and bacterial resistance to osmotic stress; however its most critical role may be its requirement for L. monocytogenes virulence and viability within host cells. A better understanding of the role of PrsA2 and PrsA-like homologs will provide insight into the dynamics of protein folding and stability in Gram-positive bacteria and may result in new strategies for optimizing protein secretion as well as inhibiting the production of virulence factors.
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Affiliation(s)
- Laty A Cahoon
- Department of Microbiology and Immunology, University of Illinois at Chicago Chicago, IL, USA
| | - Nancy E Freitag
- Department of Microbiology and Immunology, University of Illinois at Chicago Chicago, IL, USA
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