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Zarzecka U, Tegtmeyer N, Sticht H, Backert S. Trimer stability of Helicobacter pylori HtrA is regulated by a natural mutation in the protease domain. Med Microbiol Immunol 2023:10.1007/s00430-023-00766-9. [PMID: 37183214 DOI: 10.1007/s00430-023-00766-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/26/2023] [Indexed: 05/16/2023]
Abstract
The human pathogen Helicobacter pylori is a major risk factor for gastric disease development. Serine protease HtrA is an important bacterial virulence factor that cleaves the cell junction proteins occludin, claudin-8 and E-cadherin, which causes gastric tissue damage. Using casein zymography, we discovered that HtrA trimer stability varies in clinical H. pylori strains. Subsequent sequence analyses revealed that HtrA trimer stability correlated with the presence of leucine or serine residue at position 171. The importance of these amino acids in determining trimer stability was confirmed by leucine-to-serine swapping experiments using isogenic H. pylori mutant strains as well as recombinant HtrA proteins. In addition, this sequence position displays a high sequence variability among various bacterial species, but generally exhibits a preference for hydrophilic amino acids. This natural L/S171 polymorphism in H. pylori may affect the protease activity of HtrA during infection, which could be of clinical importance and may determine gastric disease development.
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Affiliation(s)
- Urszula Zarzecka
- Division of Microbiology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Nicole Tegtmeyer
- Division of Microbiology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Heinrich Sticht
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Steffen Backert
- Division of Microbiology, Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.
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2
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Ronzetti M, Baljinnyam B, Jalal I, Pal U, Simeonov A. Application of biophysical methods for improved protein production and characterization: A case study on an high-temperature requirement A-family bacterial protease. Protein Sci 2022; 31:e4498. [PMID: 36334045 PMCID: PMC9679970 DOI: 10.1002/pro.4498] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 11/02/2022] [Accepted: 11/02/2022] [Indexed: 11/07/2022]
Abstract
The high-temperature requirement A (HtrA) serine protease family presents an attractive target class for antibacterial therapeutics development. These proteins possess dual protease and chaperone functions and contain numerous binding sites and regulatory loops, displaying diverse oligomerization patterns dependent on substrate type and occupancy. HtrA proteins that are natively purified coelute with contaminating peptides and activating species, shifting oligomerization and protein structure to differently activated populations. Here, a redesigned HtrA production results in cleaner preparations with high yields by overexpressing and purifying target protein from inclusion bodies under denaturing conditions, followed by a high-throughput screen for optimal refolding buffer composition using function-agnostic biophysical techniques that do not rely on target-specific measurements. We use Borrelia burgdorferi HtrA to demonstrate the effectiveness of our function-agnostic approach, while characterization with both new and established biophysical methods shows the retention of proteolytic and chaperone activity of the refolded protein. This systematic workflow and toolset will translate to the production of HtrA-family proteins in higher quantities of pure and monodisperse composition than the current literature standard, with applicability to a broad array of protein purification strategies.
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Affiliation(s)
- Michael Ronzetti
- National Center for Advancing Translational SciencesNational Institutes of HealthRockvilleMarylandUSA
- Department of Veterinary Medicine, College of Agriculture & Natural ResourcesUniversity of MarylandCollege ParkMarylandUSA
| | - Bolormaa Baljinnyam
- National Center for Advancing Translational SciencesNational Institutes of HealthRockvilleMarylandUSA
| | | | - Utpal Pal
- Department of Veterinary Medicine, College of Agriculture & Natural ResourcesUniversity of MarylandCollege ParkMarylandUSA
| | - Anton Simeonov
- National Center for Advancing Translational SciencesNational Institutes of HealthRockvilleMarylandUSA
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3
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Zarzecka U, Matkowska D, Backert S, Skorko-Glonek J. Importance of two PDZ domains for the proteolytic and chaperone activities of Helicobacter pylori serine protease HtrA. Cell Microbiol 2020; 23:e13299. [PMID: 33277762 DOI: 10.1111/cmi.13299] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/12/2022]
Abstract
The Helicobacter pylori HtrA protein (HtrAHp ) is an important virulence factor involved in the infection process by proteolysis of components of the tight (claudin-8 and occludin) and adherens junctions (E-cadherin) between epithelial cells. As a protease and chaperone, HtrAHp is involved in protein quality control, which is particularly important under stress conditions. HtrAHp contains a protease domain and two C-terminal PDZ domains (PDZ1 and PDZ2). In the HtrA protein family, the PDZ domains are proposed to play important roles, including regulation of proteolytic activity. We therefore mutated the PDZ1 and PDZ2 domains in HtrAHp and studied the maintenance of proteolytic activity, assembly and rearrangement of the corresponding oligomeric forms. Our in vitro experiments demonstrated that at least PDZ1 is important for efficient substrate cleavage, while both PDZ domains are dispensable for the chaperone-like activity. However, in living H. pylori cells, only the mutant containing at least PDZ1, but not PDZ2, ensured bacterial growth under stressful conditions. Moreover, we can demonstrate that PDZ1 is crucial for HtrAHp oligomerization. Interestingly, all truncated proteolytically active HtrAHp variants were functional in the in vitro infection assay and caused damage to the E-cadherin-based adherens junctions. These findings provide valuable new insights into the function of HtrAHp in an important pathogen of humans.
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Affiliation(s)
- Urszula Zarzecka
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland.,Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Dorota Matkowska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Steffen Backert
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Joanna Skorko-Glonek
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
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Sharafutdinov I, Esmaeili DS, Harrer A, Tegtmeyer N, Sticht H, Backert S. Campylobacter jejuni Serine Protease HtrA Cleaves the Tight Junction Component Claudin-8. Front Cell Infect Microbiol 2020; 10:590186. [PMID: 33364202 PMCID: PMC7752809 DOI: 10.3389/fcimb.2020.590186] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 10/27/2020] [Indexed: 12/12/2022] Open
Abstract
Campylobacter jejuni express the high temperature requirement protein A (HtrA), a secreted serine protease, which is implicated in virulence properties of the pathogen. Previous studies have shown that C. jejuni HtrA can cleave the epithelial transmembrane proteins occludin and E-cadherin in the tight and adherens junctions, respectively. In the present report, we studied the interaction of HtrA with another human tight junction protein, claudin-8. Confocal immunofluorescence experiments have shown that C. jejuni infection of the intestinal polarized epithelial cells in vitro leads to a relocation of claudin-8. Wild-type C. jejuni induced the downregulation of claudin-8 signals in the tight junctions and an accumulation of claudin-8 agglomerates in the cytoplasm, which were not seen during infection with isogenic ΔhtrA knockout deletion or protease-inactive S197A point mutants. Western blotting of protein samples from infected vs. uninfected cells revealed that an 18-kDa carboxy-terminal fragment is cleaved-off from the 26-kDa full-length claudin-8 protein, but not during infection with the isogenic ΔhtrA mutant. These results were confirmed by in vitro cleavage assays using the purified recombinant C. jejuni HtrA and human claudin-8 proteins. Recombinant HtrA cleaved purified claudin-8 in vitro giving rise to the same 18-kDa sized carboxy-terminal cleavage product. Mapping studies revealed that HtrA cleavage occurs in the first extracellular loop of claudin-8. Three-dimensional modeling of the claudin-8 structure identified an exposed HtrA cleavage site between the amino acids alanine 58 and asparagine 59, which is in well agreement with the mapping studies. Taken together, HtrA operates as a secreted virulence factor targeting multiple proteins both in the tight and adherens junctions. This strategy may help the bacteria to open the cell-to-cell junctions, and to transmigrate across the intestinal epithelium by a paracellular mechanism and establish an acute infection.
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Affiliation(s)
- Irshad Sharafutdinov
- Department of Biology, Division of Microbiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Delara Soltan Esmaeili
- Department of Biology, Division of Microbiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Aileen Harrer
- Department of Biology, Division of Microbiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Nicole Tegtmeyer
- Department of Biology, Division of Microbiology, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Heinrich Sticht
- Division of Bioinformatics, Institute of Biochemistry, University of Erlangen-Nuremberg, Erlangen, Germany
| | - Steffen Backert
- Department of Biology, Division of Microbiology, University of Erlangen-Nuremberg, Erlangen, Germany
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Zarzecka U, Grinzato A, Kandiah E, Cysewski D, Berto P, Skorko-Glonek J, Zanotti G, Backert S. Functional analysis and cryo-electron microscopy of Campylobacterjejuni serine protease HtrA. Gut Microbes 2020; 12:1-16. [PMID: 32960677 PMCID: PMC7524362 DOI: 10.1080/19490976.2020.1810532] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Campylobacter jejuni is a predominant zoonotic pathogen causing gastroenteritis and other diseases in humans. An important bacterial virulence factor is the secreted serine protease HtrA (HtrA Cj ), which targets tight and adherens junctional proteins in the gut epithelium. Here we have investigated the function and structure of HtrA Cj using biochemical assays and cryo-electron microscopy. Mass spectrometry analysis identified differences and similarities in the cleavage site specificity for HtrA Cj by comparison to the HtrA counterparts from Helicobacter pylori and Escherichia coli. We defined the architecture of HtrA Cj at 5.8 Å resolution as a dodecamer, built of four trimers. The contacts between the trimers are quite loose, a fact that explains the flexibility and mobility of the dodecameric assembly. This flexibility has also been studied through molecular dynamics simulation, which revealed opening of the dodecamer to expose the proteolytically active site of the protease. Moreover, we examined the rearrangements at the level of oligomerization in the presence or absence of substrate using size exclusion chromatography, which revealed hexamers, dodecamers and larger oligomeric forms, as well as remarkable stability of higher oligomeric forms (> 12-mers) compared to previously tested homologs from other bacteria. Extremely dynamic decay of the higher oligomeric forms into lower forms was observed after full cleavage of the substrate by the proteolytically active variant of HtrA Cj . Together, this is the first report on the in-depth functional and structural analysis of HtrA Cj , which may allow the construction of therapeutically relevant HtrA Cj inhibitors in the near future.
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Affiliation(s)
- Urszula Zarzecka
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany,Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | | | | | - Dominik Cysewski
- Mass Spectrometry Laboratory, Institute of Biochemistry and Biophysics, Polish Academy of Science, Warsaw, Poland
| | - Paola Berto
- Department of Biomedical Sciences, University of Padua, Padova, Italy
| | - Joanna Skorko-Glonek
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Giuseppe Zanotti
- Department of Biomedical Sciences, University of Padua, Padova, Italy,Giuseppe Zanotti Department of Biomedical Sciences, University of Padua, Padova, Italy
| | - Steffen Backert
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany,CONTACT Steffen Backert Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nuremberg, Erlangen, Germany
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6
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Qi W, Li XX, Guo YH, Bao YZ, Wang N, Luo XG, Yu CD, Zhang TC. Integrated metabonomic-proteomic analysis reveals the effect of glucose stress on metabolic adaptation of Lactococcus lactis ssp. lactis CICC23200. J Dairy Sci 2020; 103:7834-7850. [PMID: 32684472 DOI: 10.3168/jds.2019-17810] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 04/14/2020] [Indexed: 12/30/2022]
Abstract
A combined proteomic and metabonomic approach was used to investigate the metabolism of Lactococcus lactis ssp. lactis subjected to glucose stress treatment. A proteomic method was used to determine 1,427 altered proteins, including 278 proteins with increased expression and 255 proteins with decreased expression. A metabonomic approach was adopted to identify 98 altered metabolites, including 62 metabolites with increased expression and 26 metabolites with decreased expression. The integrated analysis indicated that the RNA and DNA mismatch repair process and energy metabolism were enhanced in response to high-glucose stress in L. lactis. Lactococcus lactis responded to glucose stress by up-regulating oxidoreductase activity, which acted on glycosyl bonds, hydrolase activity, and organic acid transmembrane transporter activity. This led to an improvement in the metabolic flux from glucose to pyruvate, lactate, acetate, and maltose. Down-regulation of amino acid transmembrane transporter, aminoacyl-transfer RNA ligase, hydroxymethyl-, formyl-, and related transferase activities resulted in a decrease in the nitrogen metabolism-associated metabolic pathway, which might be related to inhibition of the production of biogenic amines. Overall, we highlight the response of metabolism to glucose stress and provide potential possibilities for the reduced formation of biogenic amines in improved level of sugar in the dairy fermentation industry. Moreover, according to the demand for industrial production, sugar concentration in fermented foods should be higher, or lower, than a set value that is dependent on bacterial strain and biogenic amine yield.
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Affiliation(s)
- Wei Qi
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China.
| | - Xiao-Xue Li
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Yao-Hua Guo
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Yan-Zhou Bao
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Nan Wang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Xue-Gang Luo
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China
| | - Chun-Di Yu
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao 266109, P.R. China
| | - Tong-Cun Zhang
- State Key Laboratory of Food Nutrition and Safety, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Key Laboratory of Industrial Fermentation Microbiology, Tianjin University of Science & Technology, Ministry of Education, Tianjin 300457, P.R. China; National Engineering Laboratory for Industrial Enzymes, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; Tianjin Key Laboratory of Industrial Microbiology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China; College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, P.R. China.
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7
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Zarzecka U, Harrer A, Zawilak-Pawlik A, Skorko-Glonek J, Backert S. Chaperone activity of serine protease HtrA of Helicobacter pylori as a crucial survival factor under stress conditions. Cell Commun Signal 2019; 17:161. [PMID: 31796064 PMCID: PMC6892219 DOI: 10.1186/s12964-019-0481-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/11/2019] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND Serine protease HtrA exhibits both proteolytic and chaperone activities, which are involved in cellular protein quality control. Moreover, HtrA is an important virulence factor in many pathogens including Helicobacter pylori, for which the crucial stage of infection is the cleavage of E-cadherin and other cell-to-cell junction proteins. METHODS The in vitro study of H. pylori HtrA (HtrAHp) chaperone activity was carried out using light scattering assays and investigation of lysozyme protein aggregates. We produced H. pylori ∆htrA deletion and HtrAHp point mutants without proteolytic activity in strain N6 and investigated the survival of the bacteria under thermal, osmotic, acidic and general stress conditions as well as the presence of puromycin or metronidazole using serial dilution tests and disk diffusion method. The levels of cellular and secreted proteins were examined using biochemical fraction and Western blotting. We also studied the proteolytic activity of secreted HtrAHp using zymography and the enzymatic digestion of β-casein. Finally, the consequences of E-cadherin cleavage were determined by immunofluorescence microscopy. RESULTS We demonstrate that HtrAHp displays chaperone activity that inhibits the aggregation of lysozyme and is stable under various pH and temperature conditions. Next, we could show that N6 expressing only HtrA chaperone activity grow well under thermal, pH and osmotic stress conditions, and in the presence of puromycin or metronidazole. In contrast, in the absence of the entire htrA gene the bacterium was more sensitive to a number of stresses. Analysing the level of cellular and secreted proteins, we noted that H. pylori lacking the proteolytic activity of HtrA display reduced levels of secreted HtrA. Moreover, we compared the amounts of secreted HtrA from several clinical H. pylori strains and digestion of β-casein. We also demonstrated a significant effect of the HtrAHp variants during infection of human epithelial cells and for E-cadherin cleavage. CONCLUSION Here we identified the chaperone activity of the HtrAHp protein and have proven that this activity is important and sufficient for the survival of H. pylori under multiple stress conditions. We also pinpointed the importance of HtrAHp chaperone activity for E- cadherin degradation and therefore for the virulence of this eminent pathogen.
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Affiliation(s)
- Urszula Zarzecka
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.,Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Aileen Harrer
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Anna Zawilak-Pawlik
- Department of Microbiology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland
| | - Joanna Skorko-Glonek
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Steffen Backert
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany.
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Zarzecka U, Modrak-Wójcik A, Figaj D, Apanowicz M, Lesner A, Bzowska A, Lipinska B, Zawilak-Pawlik A, Backert S, Skorko-Glonek J. Properties of the HtrA Protease From Bacterium Helicobacter pylori Whose Activity Is Indispensable for Growth Under Stress Conditions. Front Microbiol 2019; 10:961. [PMID: 31130939 PMCID: PMC6509562 DOI: 10.3389/fmicb.2019.00961] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Accepted: 04/16/2019] [Indexed: 12/22/2022] Open
Abstract
The protease high temperature requirement A from the gastric pathogen Helicobacter pylori (HtrAHp) belongs to the well conserved family of serine proteases. HtrAHp is an important secreted virulence factor involved in the disruption of tight and adherens junctions during infection. Very little is known about the function of HtrAHp in the H. pylori cell physiology due to the lack of htrA knockout strains. Here, using a newly constructed ΔhtrA mutant strain, we found that bacteria deprived of HtrAHp showed increased sensitivity to certain types of stress, including elevated temperature, pH and osmotic shock, as well as treatment with puromycin. These data indicate that HtrAHp plays a protective role in the H. pylori cell, presumably associated with maintenance of important periplasmic and outer membrane proteins. Purified HtrAHp was shown to be very tolerant to a wide range of temperature and pH values. Remarkably, the protein exhibited a very high thermal stability with the melting point (Tm) values of above 85°C. Moreover, HtrAHp showed the capability to regain its active structure following treatment under denaturing conditions. Taken together, our work demonstrates that HtrAHp is well adapted to operate under harsh conditions as an exported virulence factor, but also inside the bacterial cell as an important component of the protein quality control system in the stressed cellular envelope.
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Affiliation(s)
- Urszula Zarzecka
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland.,Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Anna Modrak-Wójcik
- Division of Biophysics, Faculty of Physics, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland
| | - Donata Figaj
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Malgorzata Apanowicz
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Adam Lesner
- Department of Environmental Technology, Faculty of Chemistry, University of Gdańsk, Gdańsk, Poland
| | - Agnieszka Bzowska
- Division of Biophysics, Faculty of Physics, Institute of Experimental Physics, University of Warsaw, Warsaw, Poland
| | - Barbara Lipinska
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
| | - Anna Zawilak-Pawlik
- Department of Microbiology, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wrocław, Poland
| | - Steffen Backert
- Division of Microbiology, Department of Biology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Joanna Skorko-Glonek
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdańsk, Gdańsk, Poland
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9
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Harrer A, Bücker R, Boehm M, Zarzecka U, Tegtmeyer N, Sticht H, Schulzke JD, Backert S. Campylobacter jejuni enters gut epithelial cells and impairs intestinal barrier function through cleavage of occludin by serine protease HtrA. Gut Pathog 2019; 11:4. [PMID: 30805031 PMCID: PMC6373145 DOI: 10.1186/s13099-019-0283-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 02/01/2019] [Indexed: 01/17/2023] Open
Abstract
Campylobacter jejuni secretes HtrA (high temperature requirement protein A), a serine protease that is involved in virulence. Here, we investigated the interaction of HtrA with the host protein occludin, a tight junction strand component. Immunofluorescence studies demonstrated that infection of polarized intestinal Caco-2 cells with C. jejuni strain 81-176 resulted in a redistribution of occludin away from the tight junctions into the cytoplasm, an effect that was also observed in human biopsies during acute campylobacteriosis. Occludin knockout Caco-2 cells were generated by CRISPR/Cas9 technology. Inactivation of this gene affected the polarization of the cells in monolayers and transepithelial electrical resistance (TER) was reduced, compared to wild-type Caco-2 cells. Although tight junctions were still being formed, occludin deficiency resulted in a slight decrease of the tight junction plaque protein ZO-1, which was redistributed off the tight junction into the lateral plasma membrane. Adherence of C. jejuni to Caco-2 cell monolayers was similar between the occludin knockout compared to wild-type cells, but invasion was enhanced, indicating that deletion of occludin allowed larger numbers of bacteria to pass the tight junctions and to reach basal membranes to target the fibronectin receptor followed by cell entry. Finally, we discovered that purified C. jejuni HtrA cleaves recombinant occludin in vitro to release a 37 kDa carboxy-terminal fragment. The same cleavage fragment was observed in Western blots upon infection of polarized Caco-2 cells with wild-type C. jejuni, but not with isogenic ΔhtrA mutants. HtrA cleavage was mapped to the second extracellular loop of occludin, and a putative cleavage site was identified. In conclusion, HtrA functions as a secreted protease targeting the tight junctions, which enables the bacteria by cleaving occludin and subcellular redistribution of other tight junction proteins to transmigrate using a paracellular mechanism and subsequently invade epithelial cells.
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Affiliation(s)
- Aileen Harrer
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Roland Bücker
- 2Institut für Klinische Physiologie, Med. Klinik m.S. Gastroenterologie, Infektiologie und Rheumatologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Manja Boehm
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Urszula Zarzecka
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany.,4Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, 80-308 Gdansk, Poland
| | - Nicole Tegtmeyer
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Heinrich Sticht
- 3Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Jörg D Schulzke
- 2Institut für Klinische Physiologie, Med. Klinik m.S. Gastroenterologie, Infektiologie und Rheumatologie, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Steffen Backert
- 1Division of Microbiology, Dept. of Biology, University of Erlangen-Nuremberg, Staudtstr. 5, 91058 Erlangen, Germany
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Figaj D, Ambroziak P, Przepiora T, Skorko-Glonek J. The Role of Proteases in the Virulence of Plant Pathogenic Bacteria. Int J Mol Sci 2019; 20:ijms20030672. [PMID: 30720762 PMCID: PMC6386880 DOI: 10.3390/ijms20030672] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 01/30/2019] [Accepted: 02/02/2019] [Indexed: 12/17/2022] Open
Abstract
A pathogenic lifestyle is inextricably linked with the constant necessity of facing various challenges exerted by the external environment (both within and outside the host). To successfully colonize the host and establish infection, pathogens have evolved sophisticated systems to combat the host defense mechanisms and also to be able to withstand adverse environmental conditions. Proteases, as crucial components of these systems, are involved in a variety of processes associated with infection. In phytopathogenic bacteria, they play important regulatory roles and modulate the expression and functioning of various virulence factors. Secretory proteases directly help avoid recognition by the plant immune systems, and contribute to the deactivation of the defense response pathways. Finally, proteases are important components of protein quality control systems, and thus enable maintaining homeostasis in stressed bacterial cells. In this review, we discuss the known protease functions and protease-regulated signaling processes associated with virulence of plant pathogenic bacteria.
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Affiliation(s)
- Donata Figaj
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
| | - Patrycja Ambroziak
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
| | - Tomasz Przepiora
- Department of General and Medical Biochemistry, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland.
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