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Li Y, Yu Z, Fan X, Xu D, Liu H, Zhao X, Wang R. A novel pathogenic species of genus Stenotrophomonas: Stenotrophomonas pigmentata sp. nov. Front Cell Infect Microbiol 2024; 14:1410385. [PMID: 38903940 PMCID: PMC11188353 DOI: 10.3389/fcimb.2024.1410385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 05/17/2024] [Indexed: 06/22/2024] Open
Abstract
Introduction Stenotrophomonas is a prominent genus owing to its dual nature. Species of this genus have many applications in industry and agriculture as plant growth-promoting rhizobacteria and microbial biological control agents, whereas species such as Stenotrophomonas maltophilia are considered one of the leading gram-negative multi-drug-resistant bacterial pathogens because of their high contribution to the increase in crude mortality and significant clinical challenge. Pathogenic Stenotrophomonas species and most clinical isolates belong to the Stenotrophomonas maltophilia complex (SMc). However, a strain highly homologous to S. terrae was isolated from a patient with pulmonary tuberculosis (TB), which aroused our interest, as S. terrae belongs to a relatively distant clade from SMc and there have been no human association reports. Methods The pathogenicity, immunological and biochemical characteristics of 610A2T were systematically evaluated. Results 610A2T is a new species of genus Stenotrophomonas, which is named as Stenotrophomonas pigmentata sp. nov. for its obvious brown water-soluble pigment. 610A2T is pathogenic and caused significant weight loss, pulmonary congestion, and blood transmission in mice because it has multiple virulence factors, haemolysis, and strong biofilm formation abilities. In addition, the cytokine response induced by this strain was similar to that observed in patients with TB, and the strain was resistant to half of the anti-TB drugs. Conclusions The pathogenicity of 610A2T may not be weaker than that of S. maltophilia. Its isolation extended the opportunistic pathogenic species to all 3 major clades of the genus Stenotrophomonas, indicating that the clinical importance of species of Stenotrophomonas other than S. maltophilia and potential risks to biological safety associated with the use of Stenotrophomonas require more attention.
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Affiliation(s)
| | | | | | | | | | | | - Ruibai Wang
- National Institute for Communicable Disease Control and Prevention, Chinese Centre for Disease Control and Prevention, Beijing, China
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2
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Gupta LK, Molla J, Prabhu AA. Story of Pore-Forming Proteins from Deadly Disease-Causing Agents to Modern Applications with Evolutionary Significance. Mol Biotechnol 2024; 66:1327-1356. [PMID: 37294530 DOI: 10.1007/s12033-023-00776-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 05/21/2023] [Indexed: 06/10/2023]
Abstract
Animal venoms are a complex mixture of highly specialized toxic molecules. Among them, pore-forming proteins (PFPs) or toxins (PFTs) are one of the major disease-causing toxic elements. The ability of the PFPs in defense and toxicity through pore formation on the host cell surface makes them unique among the toxin proteins. These features made them attractive for academic and research purposes for years in the areas of microbiology as well as structural biology. All the PFPs share a common mechanism of action for the attack of host cells and pore formation in which the selected pore-forming motifs of the host cell membrane-bound protein molecules drive to the lipid bilayer of the cell membrane and eventually produces water-filled pores. But surprisingly their sequence similarity is very poor. Their existence can be seen both in a soluble state and also in transmembrane complexes in the cell membrane. PFPs are prevalent toxic factors that are predominately produced by all kingdoms of life such as virulence bacteria, nematodes, fungi, protozoan parasites, frogs, plants, and also from higher organisms. Nowadays, multiple approaches to applications of PFPs have been conducted by researchers both in basic as well as applied biological research. Although PFPs are very devastating for human health nowadays researchers have been successful in making these toxic proteins into therapeutics through the preparation of immunotoxins. We have discussed the structural, and functional mechanism of action, evolutionary significance through dendrogram, domain organization, and practical applications for various approaches. This review aims to emphasize the PFTs to summarize toxic proteins together for basic knowledge as well as to highlight the current challenges, and literature gap along with the perspective of promising biotechnological applications for their future research.
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Affiliation(s)
- Laxmi Kumari Gupta
- Bioprocess Development Laboratory, Department of Biotechnology, National Institute of Technology Warangal, Warangal, Telangana, 506004, India
| | - Johiruddin Molla
- Ghatal Rabindra Satabarsiki Mahavidyalaya Ghatal, Paschim Medinipur, Ghatal, West Bengal, 721212, India
| | - Ashish A Prabhu
- Bioprocess Development Laboratory, Department of Biotechnology, National Institute of Technology Warangal, Warangal, Telangana, 506004, India.
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Alder A, Sanchez CP, Russell MRG, Collinson LM, Lanzer M, Blackman MJ, Gilberger TW, Matz JM. The role of Plasmodium V-ATPase in vacuolar physiology and antimalarial drug uptake. Proc Natl Acad Sci U S A 2023; 120:e2306420120. [PMID: 37463201 PMCID: PMC10372686 DOI: 10.1073/pnas.2306420120] [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: 04/24/2023] [Accepted: 06/20/2023] [Indexed: 07/20/2023] Open
Abstract
To ensure their survival in the human bloodstream, malaria parasites degrade up to 80% of the host erythrocyte hemoglobin in an acidified digestive vacuole. Here, we combine conditional reverse genetics and quantitative imaging approaches to demonstrate that the human malaria pathogen Plasmodium falciparum employs a heteromultimeric V-ATPase complex to acidify the digestive vacuole matrix, which is essential for intravacuolar hemoglobin release, heme detoxification, and parasite survival. We reveal an additional function of the membrane-embedded V-ATPase subunits in regulating morphogenesis of the digestive vacuole independent of proton translocation. We further show that intravacuolar accumulation of antimalarial chemotherapeutics is surprisingly resilient to severe deacidification of the vacuole and that modulation of V-ATPase activity does not affect parasite sensitivity toward these drugs.
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Affiliation(s)
- Arne Alder
- Cell Biology of Human Parasites Group, Centre for Structural Systems Biology, Hamburg22607, Germany
- Cellular Parasitology Department, Bernhard Nocht Institute for Tropical Medicine, Hamburg20359, Germany
- Department of Biology, University of Hamburg, Hamburg20146, Germany
| | - Cecilia P. Sanchez
- Center of Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg69120, Germany
| | - Matthew R. G. Russell
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, LondonNW1 1AT, United Kingdom
- Centre for Ultrastructural Imaging, King’s College London, LondonSE1 1UL, United Kingdom
| | - Lucy M. Collinson
- Electron Microscopy Science Technology Platform, The Francis Crick Institute, LondonNW1 1AT, United Kingdom
| | - Michael Lanzer
- Center of Infectious Diseases, Parasitology, Heidelberg University Hospital, Heidelberg69120, Germany
| | - Michael J. Blackman
- Malaria Biochemistry Laboratory, The Francis Crick Institute, LondonNW1 1AT, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, LondonWC1E 7HT, United Kingdom
| | - Tim-Wolf Gilberger
- Cell Biology of Human Parasites Group, Centre for Structural Systems Biology, Hamburg22607, Germany
- Cellular Parasitology Department, Bernhard Nocht Institute for Tropical Medicine, Hamburg20359, Germany
- Department of Biology, University of Hamburg, Hamburg20146, Germany
| | - Joachim M. Matz
- Cell Biology of Human Parasites Group, Centre for Structural Systems Biology, Hamburg22607, Germany
- Cellular Parasitology Department, Bernhard Nocht Institute for Tropical Medicine, Hamburg20359, Germany
- Malaria Biochemistry Laboratory, The Francis Crick Institute, LondonNW1 1AT, United Kingdom
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4
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Jenkins C, Micallef ML, Padula MP, Bogema DR. Characterisation of the Theileria orientalis Piroplasm Proteome across Three Common Genotypes. Pathogens 2022; 11:pathogens11101135. [PMID: 36297192 PMCID: PMC9610513 DOI: 10.3390/pathogens11101135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/27/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022] Open
Abstract
Theileria orientalis is an emerging apicomplexan pathogen of cattle occurring in areas populated by the principal vector tick, Haemaphysalis longicornis. Unlike transforming Theileria spp. that induce cancer-like proliferation of lymphocytes via their schizont stage, T. orientalis destroys host erythrocytes during its piroplasm phase resulting in anaemia. The underlying pathogenic processes of T. orientalis infection are poorly understood; consequently, there are no vaccines for prevention of T. orientalis infection and chemotherapeutic options are limited. To identify antigens expressed during the piroplasm phase of T. orientalis, including those which may be useful targets for future therapeutic development, we examined the proteome across three common genotypes of the parasite (Ikeda, Chitose and Buffeli) using preparations of piroplasms purified from bovine blood. A combination of Triton X-114 extraction, one-dimensional electrophoresis and LC-MS/MS identified a total of 1113 proteins across all genotypes, with less than 3% of these representing host-derived proteins. Just over three quarters of T. orientalis proteins (78%) identified were from the aqueous phase of the TX-114 extraction representing cytosolic proteins, with the remaining 22% from the detergent phase, representing membrane-associated proteins. All enzymes involved in glycolysis were expressed, suggesting that this is the major metabolic pathway used during the T. orientalis piroplasm phase. Proteins involved in binding and breakdown of haemoglobin were also identified, suggesting that T. orientalis uses haemoglobin as a source of amino acids. A number of proteins involved in host cell interaction were also identified which may be suitable targets for the development of chemotherapeutics or vaccines.
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Affiliation(s)
- Cheryl Jenkins
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia
- Correspondence: ; Tel.: +61-2-4640-6396
| | - Melinda L. Micallef
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia
| | - Matthew P. Padula
- School of Life Sciences, Faculty of Sciences, University of Technology, Sydney, NSW 2007, Australia
| | - Daniel R. Bogema
- NSW Department of Primary Industries, Elizabeth Macarthur Agricultural Institute, Menangle, NSW 2568, Australia
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5
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Wunderlich J. Updated List of Transport Proteins in Plasmodium falciparum. Front Cell Infect Microbiol 2022; 12:926541. [PMID: 35811673 PMCID: PMC9263188 DOI: 10.3389/fcimb.2022.926541] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
Malaria remains a leading cause of death and disease in many tropical and subtropical regions of the world. Due to the alarming spread of resistance to almost all available antimalarial drugs, novel therapeutic strategies are urgently needed. As the intracellular human malaria parasite Plasmodium falciparum depends entirely on the host to meet its nutrient requirements and the majority of its transmembrane transporters are essential and lack human orthologs, these have often been suggested as potential targets of novel antimalarial drugs. However, membrane proteins are less amenable to proteomic tools compared to soluble parasite proteins, and have thus not been characterised as well. While it had been proposed that P. falciparum had a lower number of transporters (2.5% of its predicted proteome) in comparison to most reference genomes, manual curation of information from various sources led to the identification of 197 known and putative transporter genes, representing almost 4% of all parasite genes, a proportion that is comparable to well-studied metazoan species. This transporter list presented here was compiled by collating data from several databases along with extensive literature searches, and includes parasite-encoded membrane-resident/associated channels, carriers, and pumps that are located within the parasite or exported to the host cell. It provides updated information on the substrates, subcellular localisation, class, predicted essentiality, and the presence or absence of human orthologs of P. falciparum transporters to quickly identify essential proteins without human orthologs for further functional characterisation and potential exploitation as novel drug targets.
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Affiliation(s)
- Juliane Wunderlich
- Max Planck Institute for Infection Biology, Berlin, Germany
- European Molecular Biology Laboratory, Hamburg Unit, Hamburg, Germany
- Centre for Structural Systems Biology, Hamburg, Germany
- *Correspondence: Juliane Wunderlich,
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6
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Nairz M, Weiss G. Iron in infection and immunity. Mol Aspects Med 2020; 75:100864. [PMID: 32461004 DOI: 10.1016/j.mam.2020.100864] [Citation(s) in RCA: 150] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 04/25/2020] [Accepted: 05/05/2020] [Indexed: 12/12/2022]
Abstract
Iron is an essential micronutrient for virtually all living cells. In infectious diseases, both invading pathogens and mammalian cells including those of the immune system require iron to sustain their function, metabolism and proliferation. On the one hand, microbial iron uptake is linked to the virulence of most human pathogens. On the other hand, the sequestration of iron from bacteria and other microorganisms is an efficient strategy of host defense in line with the principles of 'nutritional immunity'. In an acute infection, host-driven iron withdrawal inhibits the growth of pathogens. Chronic immune activation due to persistent infection, autoimmune disease or malignancy however, sequesters iron not only from infectious agents, autoreactive lymphocytes and neoplastic cells but also from erythroid progenitors. This is one of the key mechanisms which collectively result in the anemia of chronic inflammation. In this review, we highlight the most important interconnections between iron metabolism and immunity, focusing on host defense against relevant infections and on the clinical consequences of anemia of inflammation.
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Affiliation(s)
- Manfred Nairz
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pneumology, Medical University of Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Infectious Diseases, Immunology, Rheumatology, Pneumology, Medical University of Innsbruck, Austria; Christian Doppler Laboratory for Iron Metabolism and Anemia Research, Medical University of Innsbruck, Austria.
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7
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Farr L, Watanabe K, Moonah S. Purification of Antibodies Against Entamoeba histolytica MIF and Their Use in Analyzing Human and Mouse Samples. Methods Mol Biol 2020; 2080:237-247. [PMID: 31745886 DOI: 10.1007/978-1-4939-9936-1_21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Macrophage migration inhibitory factor (MIF) is a proinflammatory and proproliferative cytokine expressed in humans. MIF homologs also exist in many pathogenic protozoans, including Entamoeba, Plasmodium, Toxoplasma, and Leishmania. Production of antibodies against parasite proteins allows for the generation of assays to measure and visualize parasite infection within hosts. In this chapter, we describe how to specifically purify antibodies against Entamoeba histolytica MIF (EhMIF), and subsequently use anti-EhMIF antibodies for ELISA on mouse and human samples and for immunohistochemistry on human tissue. These methods can be applied to any protein for high-quality antibody purification.
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Affiliation(s)
- Laura Farr
- University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Koji Watanabe
- National Center for Global Health and Medicine, Shinjuku, Tokyo, Japan
| | - Shannon Moonah
- Department of Medicine, University of Virginia School of Medicine, Charlottesville, VA, USA.
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8
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Martin RE. The transportome of the malaria parasite. Biol Rev Camb Philos Soc 2019; 95:305-332. [PMID: 31701663 DOI: 10.1111/brv.12565] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 10/02/2019] [Accepted: 10/04/2019] [Indexed: 12/15/2022]
Abstract
Membrane transport proteins, also known as transporters, control the movement of ions, nutrients, metabolites, and waste products across the membranes of a cell and are central to its biology. Proteins of this type also serve as drug targets and are key players in the phenomenon of drug resistance. The malaria parasite has a relatively reduced transportome, with only approximately 2.5% of its genes encoding transporters. Even so, assigning functions and physiological roles to these proteins, and ascertaining their contributions to drug action and drug resistance, has been very challenging. This review presents a detailed critique and synthesis of the disruption phenotypes, protein subcellular localisations, protein functions (observed or predicted), and links to antimalarial drug resistance for each of the parasite's transporter genes. The breadth and depth of the gene disruption data are particularly impressive, with at least one phenotype determined in the parasite's asexual blood stage for each transporter gene, and multiple phenotypes available for 76% of the genes. Analysis of the curated data set revealed there to be relatively little redundancy in the Plasmodium transportome; almost two-thirds of the parasite's transporter genes are essential or required for normal growth in the asexual blood stage of the parasite, and this proportion increased to 78% when the disruption phenotypes available for the other parasite life stages were included in the analysis. These observations, together with the finding that 22% of the transportome is implicated in the parasite's resistance to existing antimalarials and/or drugs within the development pipeline, indicate that transporters are likely to serve, or are already serving, as drug targets. Integration of the different biological and bioinformatic data sets also enabled the selection of candidates for transport processes known to be essential for parasite survival, but for which the underlying proteins have thus far remained undiscovered. These include potential transporters of pantothenate, isoleucine, or isopentenyl diphosphate, as well as putative anion-selective channels that may serve as the pore component of the parasite's 'new permeation pathways'. Other novel insights into the parasite's biology included the identification of transporters for the potential development of antimalarial treatments, transmission-blocking drugs, prophylactics, and genetically attenuated vaccines. The syntheses presented herein set a foundation for elucidating the functions and physiological roles of key members of the Plasmodium transportome and, ultimately, to explore and realise their potential as therapeutic targets.
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Affiliation(s)
- Rowena E Martin
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
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9
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Ramírez-Carreto S, Pérez-García EI, Salazar-García SI, Bernáldez-Sarabia J, Licea-Navarro A, Rudiño-Piñera E, Pérez-Martínez L, Pedraza-Alva G, Rodríguez-Almazán C. Identification of a pore-forming protein from sea anemone Anthopleura dowii Verrill (1869) venom by mass spectrometry. J Venom Anim Toxins Incl Trop Dis 2019; 25:e147418. [PMID: 31131002 PMCID: PMC6483413 DOI: 10.1590/1678-9199-jvatitd-1474-18] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/13/2018] [Indexed: 12/14/2022] Open
Abstract
Background: Pore-forming proteins (PFP) are a class of toxins abundant in the venom of
sea anemones. Owing to their ability to recognize and permeabilize cell
membranes, pore-forming proteins have medical potential in cancer therapy or
as biosensors. In the present study, we showed the partial purification and
sequencing of a pore-forming protein from Anthopleura dowii
Verrill (1869). 17. Methods: Cytolytic activity of A. dowii Verrill (1869) venom was
determined via hemolysis assay in the erythrocytes of four mammals (sheep,
goat, human and rabbit). The cytotoxic activity was analyzed in the human
adherent lung carcinoma epithelial cells (A549) by the cytosolic lactate
dehydrogenase (LDH) assay, and trypan blue staining. The venom was
fractionated via ammonium sulfate precipitation gradient, dialysis, and ion
exchange chromatography. The presence of a pore-forming protein in purified
fractions was evaluated through hemolytic and cytotoxic assays, and the
activity fraction was analyzed using the percent of osmotic protections
after polyethylene glycol (PEG) treatment and mass spectrometry. 18. Results: The amount of protein at which the venom produced 50% hemolysis
(HU50) was determined in hemolysis assays using erythrocytes
from sheep (HU50 = 10.7 ± 0.2 μg), goat (HU50 = 13.2 ±
0.3 μg), rabbit (HU50 = 34.7 ± 0.5 μg), and human
(HU50 = 25.6 ± 0.6 μg). The venom presented a cytotoxic
effect in A549 cells and the protein amount present in the venom responsible
for producing 50% death (IC50) was determined using a trypan blue
cytotoxicity assay (1.84 ± 0.40 μg/mL). The loss of membrane integrity in
the A549 cells caused by the venom was detected by the release of LDH in
proportion to the amount of protein. The venom was fractionated; and the
fraction with hemolytic and cytotoxic activities was analyzed by mass
spectrometry. A pore-forming protein was identified. The cytotoxicity in the
A549 cells produced by the fraction containing the pore-forming protein was
osmotically protected by PEG-3350 Da molecular mass, which corroborated that
the loss of integrity in the plasma membrane was produced via pore
formation. 19. Conclusion: A. dowii Verrill (1869) venom
contains a pore-forming protein suitable for designing new drugs for cancer
therapy.
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Affiliation(s)
- Santos Ramírez-Carreto
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Erick I Pérez-García
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Sandra I Salazar-García
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Johanna Bernáldez-Sarabia
- Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Innovación Biomédica, Baja California, México
| | - Alexei Licea-Navarro
- Centro de Investigación Científica y de Educación Superior de Ensenada, Departamento de Innovación Biomédica, Baja California, México
| | - Enrique Rudiño-Piñera
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Leonor Pérez-Martínez
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Gustavo Pedraza-Alva
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
| | - Claudia Rodríguez-Almazán
- Universidad Nacional Autónoma de México, Instituto de Biotecnología, Departamento de Medicina Molecular y Bioprocesos, Av. Universidad 2001, Cuernavaca, Morelos, México
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Divyakolu S, Chikkala R, Ratnakar KS, Sritharan V. Hemolysins of <i>Staphylococcus aureus</i>—An Update on Their Biology, Role in Pathogenesis and as Targets for Anti-Virulence Therapy. ACTA ACUST UNITED AC 2019. [DOI: 10.4236/aid.2019.92007] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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11
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Noreen Z, Jobichen C, Abbasi R, Seetharaman J, Sivaraman J, Bokhari H. Structural basis for the pathogenesis of Campylobacter jejuni Hcp1, a structural and effector protein of the Type VI Secretion System. FEBS J 2018; 285:4060-4070. [PMID: 30194714 DOI: 10.1111/febs.14650] [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: 06/26/2018] [Revised: 08/17/2018] [Accepted: 09/03/2018] [Indexed: 12/22/2022]
Abstract
The Type VI Secretion System (T6SS) provides enhanced virulence to Campylobacter jejuni and has been associated with a high incidence of bloody diarrhea. The hemolysin-coregulated protein (Hcp)-the hallmark of the T6SS-can act as a structural and effector protein. Unlike other T6SS-harboring bacteria, which possess multiple Hcp proteins each performing different functions, C. jejuni possesses only one Hcp protein, and its structural and functional role has not been elucidated previously. Here, we report the structure and functional studies of Hcp from C. jejuni. We found similarities between the hexameric ring structure of Hcp-Cj and that of Hcp3 from Pseudomonas aeruginosa. Through functional studies, we showed two roles for Hcp-Cj that is, in cytotoxicity toward HepG2 cells and in biofilm formation in C. jejuni. In structure-based mutational analyses, we showed that an Arg-to-Ala mutation at position 30 within the extended loop results in a significant decrease in cytotoxicity, suggesting a role for this loop in binding to the host cell. However, this mutation does not affect its biofilm formation function. Collectively, this study supports the dual role of Hcp-Cj as a structural and effector protein in C. jejuni.
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Affiliation(s)
- Zobia Noreen
- Department of Biosciences, COMSATS University, Islamabad Campus, Islamabad, Pakistan
| | - Chacko Jobichen
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Rashda Abbasi
- Institute of Biomedical and Genetic Engineering (IBGE), Islamabad, Pakistan
| | | | - J Sivaraman
- Department of Biological Sciences, Faculty of Science, National University of Singapore, Singapore
| | - Habib Bokhari
- Department of Biosciences, COMSATS University, Islamabad Campus, Islamabad, Pakistan
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