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Oka GU, Souza DP, Sgro GG, Guzzo CR, Dunger G, Farah CS. Xanthomonas immunity proteins protect against the cis-toxic effects of their cognate T4SS effectors. EMBO Rep 2024; 25:1436-1452. [PMID: 38332152 PMCID: PMC10933484 DOI: 10.1038/s44319-024-00060-6] [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: 09/07/2023] [Revised: 12/22/2023] [Accepted: 01/08/2024] [Indexed: 02/10/2024] Open
Abstract
Many bacteria kill rival species by translocating toxic effectors into target cells. Effectors are often encoded along with cognate immunity proteins that could (i) protect against "friendly-fire" (trans-intoxication) from neighboring sister cells and/or (ii) protect against internal cis-intoxication (suicide). Here, we distinguish between these two mechanisms in the case of the bactericidal Xanthomonas citri Type IV Secretion System (X-T4SS). We use a set of X. citri mutants lacking multiple effector/immunity protein (X-Tfe/X-Tfi) pairs to show that X-Tfis are not absolutely required to protect against trans-intoxication by wild-type cells. Our investigation then focused on the in vivo function of the lysozyme-like effector X-TfeXAC2609 and its cognate immunity protein X-TfiXAC2610. In the absence of X-TfiXAC2610, we observe X-TfeXAC2609-dependent and X-T4SS-independent accumulation of damage in the X. citri cell envelope, cell death, and inhibition of biofilm formation. While immunity proteins in other systems have been shown to protect against attacks by sister cells (trans-intoxication), this is an example of an antibacterial secretion system in which the immunity proteins are dedicated to protecting cells against cis-intoxication.
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Affiliation(s)
- Gabriel U Oka
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
- Structure and Function of Bacterial Nanomachines, Institut Européen de Chimie et Biologie-CNRS, UMR 5234 Microbiologie Fondamentale et Pathogénicité University of Bordeaux, Pessac, France
| | - Diorge P Souza
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Germán G Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
- Departamento de Ciências BioMoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Cristiane R Guzzo
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP, Brazil
| | - German Dunger
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil
- Instituto de Ciencias Agropecuarias del Litoral (ICiAgro Litoral), Universidad Nacional del Litoral, CONICET, Facultad de Ciencias Agrarias, Esperanza, Argentina
| | - Chuck S Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP, Brazil.
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2
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Rosa IF, Peçanha APB, Carvalho TRB, Alexandre LS, Ferreira VG, Doretto LB, Souza BM, Nakajima RT, da Silva P, Barbosa AP, Gomes-de-Pontes L, Bomfim CG, Machado-Santelli GM, Condino-Neto A, Guzzo CR, Peron JPS, Andrade-Silva M, Câmara NOS, Garnique AMB, Medeiros RJ, Ferraris FK, Barcellos LJG, Correia-Junior JD, Galindo-Villegas J, Machado MFR, Castoldi A, Oliveira SL, Costa CC, Belo MAA, Galdino G, Sgro GG, Bueno NF, Eto SF, Veras FP, Fernandes BHV, Sanches PRS, Cilli EM, Malafaia G, Nóbrega RH, Garcez AS, Carrilho E, Charlie-Silva I. Photobiomodulation Reduces the Cytokine Storm Syndrome Associated with COVID-19 in the Zebrafish Model. Int J Mol Sci 2023; 24:ijms24076104. [PMID: 37047078 PMCID: PMC10094635 DOI: 10.3390/ijms24076104] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/11/2023] [Accepted: 03/14/2023] [Indexed: 04/14/2023] Open
Abstract
Although the exact mechanism of the pathogenesis of coronavirus SARS-CoV-2 (COVID-19) is not fully understood, oxidative stress and the release of pro-inflammatory cytokines have been highlighted as playing a vital role in the pathogenesis of the disease. In this sense, alternative treatments are needed to reduce the level of inflammation caused by COVID-19. Therefore, this study aimed to investigate the potential effect of red photobiomodulation (PBM) as an attractive therapy to downregulate the cytokine storm caused by COVID-19 in a zebrafish model. RT-qPCR analyses and protein-protein interaction prediction among SARS-CoV-2 and Danio rerio proteins showed that recombinant Spike protein (rSpike) was responsible for generating systemic inflammatory processes with significantly increased levels of pro-inflammatory (il1b, il6, tnfa, and nfkbiab), oxidative stress (romo1) and energy metabolism (slc2a1a and coa1) mRNA markers, with a pattern similar to those observed in COVID-19 cases in humans. On the other hand, PBM treatment was able to decrease the mRNA levels of these pro-inflammatory and oxidative stress markers compared with rSpike in various tissues, promoting an anti-inflammatory response. Conversely, PBM promotes cellular and tissue repair of injured tissues and significantly increases the survival rate of rSpike-inoculated individuals. Additionally, metabolomics analysis showed that the most-impacted metabolic pathways between PBM and the rSpike treated groups were related to steroid metabolism, immune system, and lipid metabolism. Together, our findings suggest that the inflammatory process is an incisive feature of COVID-19 and red PBM can be used as a novel therapeutic agent for COVID-19 by regulating the inflammatory response. Nevertheless, the need for more clinical trials remains, and there is a significant gap to overcome before clinical trials can commence.
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Affiliation(s)
- Ivana F Rosa
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 01049-010, Brazil
| | - Ana P B Peçanha
- Department of Orthodontics, São Leopoldo Mandic College, Campinas 13045-755, Brazil
| | - Tábata R B Carvalho
- Department of Orthodontics, São Leopoldo Mandic College, Campinas 13045-755, Brazil
| | - Leonardo S Alexandre
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos 13566-590, Brazil
- The National Institute of Science and Technology in Bioanalyses, INCTBio, Campinas 13083-970, Brazil
| | - Vinícius G Ferreira
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos 13566-590, Brazil
- The National Institute of Science and Technology in Bioanalyses, INCTBio, Campinas 13083-970, Brazil
| | - Lucas B Doretto
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 01049-010, Brazil
| | - Beatriz M Souza
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 01049-010, Brazil
| | - Rafael T Nakajima
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 01049-010, Brazil
| | - Patrick da Silva
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Ana P Barbosa
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Leticia Gomes-de-Pontes
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Camila G Bomfim
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | | | - Antonio Condino-Neto
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Cristiane R Guzzo
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Jean P S Peron
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Magaiver Andrade-Silva
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Niels O S Câmara
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | - Anali M B Garnique
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo 05508-220, Brazil
| | | | | | - Leonardo J G Barcellos
- Laboratório de Fisiologia de Peixes, Programa de Pós-Graduação em Bioexperimentação, Escola de Ciências Agrárias, Inovação e Negócios, Universidade de Passo Fundo, Passo Fundo 99052-900, Brazil
| | - Jose D Correia-Junior
- Institute of Biomedical Sciences, Federal University Minas Gerais, Belo Horizonte 31270-901, Brazil
| | - Jorge Galindo-Villegas
- Department of Genomics, Faculty of Biosciences and Aquaculture, Nord University, 8026 Bodø, Norway
| | - Mônica F R Machado
- Biological Sciences Special Academic Unit, Federal University of Jatai, Jatai 75804-020, Brazil
| | - Angela Castoldi
- Keizo Asami Institute, Federal University of Pernambuco, Recife 50670-901, Brazil
| | - Susana L Oliveira
- School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, Brazil
| | - Camila C Costa
- School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, Brazil
| | - Marco A A Belo
- School of Agricultural and Veterinary Sciences, São Paulo State University (UNESP), Jaboticabal 14884-900, Brazil
| | - Giovane Galdino
- Institute of Motricity Sciences, Department of Physical Therapy, Federal University of Alfenas, Alfenas 37133-840, Brazil
| | - Germán G Sgro
- Departamento de Ciências Biomoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, São Paulo 14040-900, Brazil
| | - Natalia F Bueno
- Integrated Structural Biology Platform, Carlos Chagas Institute, FIOCRUZ Paraná, Curitiba 81310-020, Brazil
| | - Silas F Eto
- Center of Innovation and Development, Laboratory of Development and Innovation Butantan Institute, São Paulo 69310-000, Brazil
| | - Flávio P Veras
- Faculty of Medicine, University of São Paulo (USP), Ribeirão Preto 14040-900, Brazil
| | - Bianca H V Fernandes
- Laboratory of Genetic and Sanitary Control, Technical Board of Support for Teaching and Research, Faculty of Medicine, University of Sao Paulo, São Paulo 01246-903, Brazil
| | - Paulo R S Sanches
- Department of Biochemistry and Organic Chemistry, Institute of Chemistry, São Paulo State University (UNESP), Araraquara 14800-060, Brazil
| | - Eduardo M Cilli
- Department of Biochemistry and Organic Chemistry, Institute of Chemistry, São Paulo State University (UNESP), Araraquara 14800-060, Brazil
| | - Guilherme Malafaia
- Laboratory of Toxicology Applied to the Environment, Goiano Federal Institute, Urutaí Campus, Urutaí 75790-000, Brazil
| | - Rafael H Nóbrega
- Department of Structural and Functional Biology, Institute of Biosciences, São Paulo State University (UNESP), Botucatu 01049-010, Brazil
| | - Aguinaldo S Garcez
- Department of Orthodontics, São Leopoldo Mandic College, Campinas 13045-755, Brazil
| | - Emanuel Carrilho
- Instituto de Química de São Carlos, Universidade de São Paulo, São Carlos 13566-590, Brazil
- The National Institute of Science and Technology in Bioanalyses, INCTBio, Campinas 13083-970, Brazil
| | - Ives Charlie-Silva
- Department of Biochemistry and Organic Chemistry, Institute of Chemistry, São Paulo State University (UNESP), Araraquara 14800-060, Brazil
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3
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Moraes BC, Ribeiro-Filho HV, Roldão AP, Toniolo EF, Carretero GPB, Sgro GG, Batista FAH, Berardi DE, Oliveira VRS, Tomasin R, Vieceli FM, Pramio DT, Cardoso AB, Figueira ACM, Farah SC, Devi LA, Dale CS, de Oliveira PSL, Schechtman D. Structural analysis of TrkA mutations in patients with congenital insensitivity to pain reveals PLCγ as an analgesic drug target. Sci Signal 2022; 15:eabm6046. [PMID: 35471943 DOI: 10.1126/scisignal.abm6046] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Chronic pain is a major health issue, and the search for new analgesics has become increasingly important because of the addictive properties and unwanted side effects of opioids. To explore potentially new drug targets, we investigated mutations in the NTRK1 gene found in individuals with congenital insensitivity to pain with anhidrosis (CIPA). NTRK1 encodes tropomyosin receptor kinase A (TrkA), the receptor for nerve growth factor (NGF) and that contributes to nociception. Molecular modeling and biochemical analysis identified mutations that decreased the interaction between TrkA and one of its substrates and signaling effectors, phospholipase Cγ (PLCγ). We developed a cell-permeable phosphopeptide derived from TrkA (TAT-pQYP) that bound the Src homology domain 2 (SH2) of PLCγ. In HEK-293T cells, TAT-pQYP inhibited the binding of heterologously expressed TrkA to PLCγ and decreased NGF-induced, TrkA-mediated PLCγ activation and signaling. In mice, intraplantar administration of TAT-pQYP decreased mechanical sensitivity in an inflammatory pain model, suggesting that targeting this interaction may be analgesic. The findings demonstrate a strategy to identify new targets for pain relief by analyzing the signaling pathways that are perturbed in CIPA.
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Affiliation(s)
- Beatriz C Moraes
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Helder V Ribeiro-Filho
- Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian Biosciences National Laboratory (LNBio) Campinas, SP 13083-100, Brazil
| | - Allan P Roldão
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Elaine F Toniolo
- Laboratory of Neuromodulation of Experimental Pain (LaNed), Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, SP 05508-000, Brazil
| | - Gustavo P B Carretero
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Germán G Sgro
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil.,Department of Biomolecular Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040903, Brazil
| | - Fernanda A H Batista
- Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian Biosciences National Laboratory (LNBio) Campinas, SP 13083-100, Brazil
| | - Damian E Berardi
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Victoria R S Oliveira
- Laboratory of Neuromodulation of Experimental Pain (LaNed), Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, SP 05508-000, Brazil
| | - Rebeka Tomasin
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Felipe M Vieceli
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Dimitrius T Pramio
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Alexandre B Cardoso
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Ana C M Figueira
- Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian Biosciences National Laboratory (LNBio) Campinas, SP 13083-100, Brazil
| | - Shaker C Farah
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
| | - Lakshmi A Devi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Camila S Dale
- Laboratory of Neuromodulation of Experimental Pain (LaNed), Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, SP 05508-000, Brazil
| | - Paulo S L de Oliveira
- Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian Biosciences National Laboratory (LNBio) Campinas, SP 13083-100, Brazil
| | - Deborah Schechtman
- Department of Biochemistry, Chemistry Institute, University of São Paulo, SP 05508-000, Brazil
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4
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Ventura Fernandes BH, Feitosa NM, Barbosa AP, Bomfim CG, Garnique AMB, Rosa IF, Rodrigues MS, Doretto LB, Costa DF, Camargo-Dos-Santos B, Franco GA, Neto JF, Lunardi JS, Bellot MS, Alves NPC, Costa CC, Aracati MF, Rodrigues LF, Costa CC, Cirilo RH, Colagrande RM, Gomes FIF, Nakajima RT, Belo MAA, Giaquinto PC, de Oliveira SL, Eto SF, Fernandes DC, Manrique WG, Conde G, Rosales RRC, Todeschini I, Rivero I, Llontop E, Sgro GG, Oka GU, Bueno NF, Ferraris FK, de Magalhães MTQ, Medeiros RJ, Mendonça-Gomes JM, Junqueira MS, Conceição K, Pontes LGD, Condino-Neto A, Perez AC, Barcellos LJG, Júnior JDC, Dorlass EG, Camara NOS, Durigon EL, Cunha FQ, Nóbrega RH, Machado-Santelli GM, Farah CS, Veras FP, Galindo-Villegas J, Costa-Lotufo LV, Cunha TM, Chammas R, Carvalho LR, Guzzo CR, Malafaia G, Charlie-Silva I. Toxicity of spike fragments SARS-CoV-2 S protein for zebrafish: A tool to study its hazardous for human health? Sci Total Environ 2022; 813:152345. [PMID: 34942250 PMCID: PMC8688160 DOI: 10.1016/j.scitotenv.2021.152345] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/17/2021] [Accepted: 12/08/2021] [Indexed: 05/19/2023]
Abstract
Despite the significant increase in the generation of SARS-CoV-2 contaminated domestic and hospital wastewater, little is known about the ecotoxicological effects of the virus or its structural components in freshwater vertebrates. In this context, this study evaluated the deleterious effects caused by SARS-CoV-2 Spike protein on the health of Danio rerio, zebrafish. We demonstrated, for the first time, that zebrafish injected with fragment 16 to 165 (rSpike), which corresponds to the N-terminal portion of the protein, presented mortalities and adverse effects on liver, kidney, ovary and brain tissues. The conserved genetic homology between zebrafish and humans might be one of the reasons for the intense toxic effects followed inflammatory reaction from the immune system of zebrafish to rSpike which provoked damage to organs in a similar pattern as happen in severe cases of COVID-19 in humans, and, resulted in 78,6% of survival rate in female adults during the first seven days. The application of spike protein in zebrafish was highly toxic that is suitable for future studies to gather valuable information about ecotoxicological impacts, as well as vaccine responses and therapeutic approaches in human medicine. Therefore, besides representing an important tool to assess the harmful effects of SARS-CoV-2 in the aquatic environment, we present the zebrafish as an animal model for translational COVID-19 research.
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Affiliation(s)
- Bianca H Ventura Fernandes
- Laboratório de Controle Genético e Sanitário, Diretoria Técnica de Apoio ao Ensino e Pesquisa, Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Natália Martins Feitosa
- Laboratório Integrado de Biociências Translacionais (LIBT), Instituto de Biodiversidade e Sustentabilidade (NUPEM), Universidade Federal do Rio de Janeiro (UFRJ), Macaé, RJ, Brazil
| | - Ana Paula Barbosa
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Camila Gasque Bomfim
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Anali M B Garnique
- Department of Cell Biology, Institute of Biomedical Sciences, University of São Paulo, Brazil
| | - Ivana F Rosa
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, Sao Paulo State University, Botucatu, São Paulo, Brazil
| | - Maira S Rodrigues
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, Sao Paulo State University, Botucatu, São Paulo, Brazil
| | - Lucas B Doretto
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, Sao Paulo State University, Botucatu, São Paulo, Brazil
| | - Daniel F Costa
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, Sao Paulo State University, Botucatu, São Paulo, Brazil
| | - Bruno Camargo-Dos-Santos
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Gabrielli A Franco
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - João Favero Neto
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Juliana Sartori Lunardi
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Marina Sanson Bellot
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Nina Pacheco Capelini Alves
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Camila C Costa
- Department of Preventive Veterinary Medicine, São Paulo State University (UNESP), Jaboticabal, Brazil
| | - Mayumi F Aracati
- Department of Preventive Veterinary Medicine, São Paulo State University (UNESP), Jaboticabal, Brazil
| | - Letícia F Rodrigues
- Department of Preventive Veterinary Medicine, São Paulo State University (UNESP), Jaboticabal, Brazil
| | - Camila C Costa
- Department of Preventive Veterinary Medicine, São Paulo State University (UNESP), Jaboticabal, Brazil
| | - Rafaela Hemily Cirilo
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Raul Marcelino Colagrande
- Department of Structural and Functional Biology, Institute of Biosciences of Botucatu, São Paulo State University, SP, Brazil
| | - Francisco I F Gomes
- Department of Pharmacology, Center of Research in Inflammatory Diseases, Ribeirao Preto Medical School, University of São Paulo, Brazil
| | - Rafael T Nakajima
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, Sao Paulo State University, Botucatu, São Paulo, Brazil
| | | | - Percília Cardoso Giaquinto
- Universidade Estadual Paulista Júlio de Mesquita Filho, Instituto de Biociências - Departamento de Fisiologia, São Paulo, Brazil
| | | | - Silas Fernandes Eto
- Postgraduate Program in Health Sciences, PROCISA, Federal University of Roraima, Brazil
| | | | - Wilson G Manrique
- Aquaculture Health Research and Extension Group, GRUPESA, Aquaculture Health Laboratory, LABSA, Department of Veterinary Medicine, Federal University of Rondônia, Rolim de Moura campus, Rondônia, Brazil
| | - Gabriel Conde
- Department of Preventive Veterinary Medicine, São Paulo State University, Jaboticabal, Brazil
| | - Roberta R C Rosales
- Department of Cell and Molecular Biology, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Iris Todeschini
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil
| | - Ilo Rivero
- Pontifícia Universidade Católica de Minas Gerais, Brazil
| | - Edgar Llontop
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil
| | - Germán G Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil; Departamento de Ciências Biomoleculares, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - Gabriel Umaji Oka
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil
| | | | - Fausto K Ferraris
- Department of Pharmacology and Toxicology, Oswaldo Cruz Foundation, FIOCRUZ, Rio de Janeiro, Brazil
| | - Mariana T Q de Magalhães
- Department of Biochemistry and Immunology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Renata J Medeiros
- Laboratory of Physiology, INCQS/Fiocruz Zebrafish Facility, Departament of Pharmacology and Toxicology, National Institute for Quality Control in Health, Brasil
| | - Juliana M Mendonça-Gomes
- Transplantation Immunobiology Lab, Department of Immunology, Institute of Biomedical Sciences, Universidade de Sao Paulo, Brazil
| | - Mara Souza Junqueira
- Center for Translational Research in Oncology, Cancer Institute of the State of Sao Paulo, Faculty of Medicine, University of São Paulo, Sao Paulo, Brazil
| | - Kátia Conceição
- Laboratory of Peptide Biochemistry, Federal University of São Paulo, Brazil
| | - Leticia Gomes de Pontes
- Laboratory of Human Immunology, Department Immunology, Institute Biomedical Sciences, University São Paulo, Sao Paulo, Brazil
| | - Antonio Condino-Neto
- Laboratory of Human Immunology, Department Immunology, Institute Biomedical Sciences, University São Paulo, Sao Paulo, Brazil
| | - Andrea C Perez
- Department of Pharmacology, Universidade Federal de Minas Gerais, Brazil
| | - Leonardo J G Barcellos
- Graduate Program of Pharmacology, Federal University of Santa Maria, Brazil; Laboratory of Fish Physiology, Graduate Program of Bioexperimentation and of Environmental Sciences, University of Passo Fundo, Brazil
| | - José Dias Correa Júnior
- Laboratório do Estudo da Interação Químico Biológica e da Reprodução Animal, LIQBRA, Bloco O3,174, Brazil; Departamento de Morfologia Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Brazil
| | - Erick Gustavo Dorlass
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Niels O S Camara
- Transplantation Immunobiology Lab, Department of Immunology, Institute of Biomedical Sciences, Universidade de Sao Paulo, Brazil
| | - Edison Luiz Durigon
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Fernando Q Cunha
- Department of Pharmacology, Center of Research in Inflammatory Diseases, Ribeirao Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Rafael H Nóbrega
- Reproductive and Molecular Biology Group, Department of Morphology, Institute of Biosciences, Sao Paulo State University, Botucatu, São Paulo, Brazil
| | - Glaucia M Machado-Santelli
- Department of Cell Biology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Chuck S Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Brazil
| | - Flavio P Veras
- Center of Research in Inflammatory Diseases, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, Sao Paulo, Brazil; Department of Pharmacology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | | | - Letícia V Costa-Lotufo
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Brazil
| | - Thiago M Cunha
- Center of Research in Inflammatory Diseases, Ribeirão Preto Medical School, University of Sao Paulo, Ribeirão Preto, Sao Paulo, Brazil; Department of Pharmacology, Ribeirao Preto Medical School, University of São Paulo, Ribeirao Preto, São Paulo, Brazil
| | - Roger Chammas
- Centro de Investigação Translacional em Oncologia, Instituto do Câncer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, Brazil
| | - Luciani R Carvalho
- Disciplina de Endocrinologia do Departamento de Clinica Medica e Laboratório de Hormônios e Genética Molecular, LIM 42, Brazil
| | - Cristiane R Guzzo
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - Guilherme Malafaia
- Biological Research Laboratory, Goiano Federal Institute, Urutaí Campus, Brazil.
| | - Ives Charlie-Silva
- Department of Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Brazil.
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Llontop EE, Cenens W, Favaro DC, Sgro GG, Salinas RK, Guzzo CR, Farah CS. The PilB-PilZ-FimX regulatory complex of the Type IV pilus from Xanthomonas citri. PLoS Pathog 2021; 17:e1009808. [PMID: 34398935 PMCID: PMC8389850 DOI: 10.1371/journal.ppat.1009808] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 08/26/2021] [Accepted: 07/17/2021] [Indexed: 11/19/2022] Open
Abstract
Type IV pili (T4P) are thin and flexible filaments found on the surface of a wide range of Gram-negative bacteria that undergo cycles of extension and retraction and participate in a variety of important functions related to lifestyle, defense and pathogenesis. During pilus extensions, the PilB ATPase energizes the polymerization of pilin monomers from the inner membrane. In Xanthomonas citri, two cytosolic proteins, PilZ and the c-di-GMP receptor FimX, are involved in the regulation of T4P biogenesis through interactions with PilB. In vivo fluorescence microscopy studies show that PilB, PilZ and FimX all colocalize to the leading poles of X. citri cells during twitching motility and that this colocalization is dependent on the presence of all three proteins. We demonstrate that full-length PilB, PilZ and FimX can interact to form a stable complex as can PilB N-terminal, PilZ and FimX C-terminal fragments. We present the crystal structures of two binary complexes: i) that of the PilB N-terminal domain, encompassing sub-domains ND0 and ND1, bound to PilZ and ii) PilZ bound to the FimX EAL domain within a larger fragment containing both GGDEF and EAL domains. Evaluation of PilZ interactions with PilB and the FimX EAL domain in these and previously published structures, in conjunction with mutagenesis studies and functional assays, allow us to propose an internally consistent model for the PilB-PilZ-FimX complex and its interactions with the PilM-PilN complex in the context of the inner membrane platform of the X. citri Type IV pilus.
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Affiliation(s)
- Edgar E. Llontop
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - William Cenens
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Denize C. Favaro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
- Departamento de Química Orgânica, Universidade Estadual de Campinas (UNICAMP), Campinas, Brazil
| | - Germán G. Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Roberto K. Salinas
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Cristiane R. Guzzo
- Departamento de Microbiologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, Brazil
| | - Chuck S. Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Cenens W, Andrade MO, Llontop E, Alvarez-Martinez CE, Sgro GG, Farah CS. Bactericidal type IV secretion system homeostasis in Xanthomonas citri. PLoS Pathog 2020; 16:e1008561. [PMID: 32453788 PMCID: PMC7286519 DOI: 10.1371/journal.ppat.1008561] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Revised: 06/10/2020] [Accepted: 04/18/2020] [Indexed: 11/19/2022] Open
Abstract
Several Xanthomonas species have a type IV secretion system (T4SS) that injects a cocktail of antibacterial proteins into neighbouring Gram-negative bacteria, often leading to rapid lysis upon cell contact. This capability represents an obvious fitness benefit since it can eliminate competition while the liberated contents of the lysed bacteria could provide an increase in the local availability of nutrients. However, the production of this Mega Dalton-sized molecular machine, with over a hundred subunits, also imposes a significant metabolic cost. Here we show that the chromosomal virB operon, which encodes the structural genes of this T4SS in X. citri, is regulated by the conserved global regulator CsrA. Relieving CsrA repression from the virB operon produced a greater number of T4SSs in the cell envelope and an increased efficiency in contact-dependent lysis of target cells. However, this was also accompanied by a physiological cost leading to reduced fitness when in co-culture with wild-type X. citri. We show that T4SS production is constitutive despite being downregulated by CsrA. Cells subjected to a wide range of rich and poor growth conditions maintain a constant density of T4SSs in the cell envelope and concomitant interbacterial competitiveness. These results show that CsrA provides a constant though partial repression on the virB operon, independent of the tested growth conditions, in this way controlling T4SS-related costs while at the same time maintaining X. citri's aggressive posture when confronted by competitors.
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Affiliation(s)
- William Cenens
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo (USP), Av. Prof. Lineu Prestes 748, São Paulo, SP, Brazil
| | - Maxuel O. Andrade
- Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, R. Giuseppe Máximo Scolfaro, Campinas, SP, Brazil
| | - Edgar Llontop
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo (USP), Av. Prof. Lineu Prestes 748, São Paulo, SP, Brazil
| | - Cristina E. Alvarez-Martinez
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), Rua Monteiro Lobato, Campinas, SP, Brazil
| | - Germán G. Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo (USP), Av. Prof. Lineu Prestes 748, São Paulo, SP, Brazil
| | - Chuck S. Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo (USP), Av. Prof. Lineu Prestes 748, São Paulo, SP, Brazil
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Sgro GG, Oka GU, Souza DP, Cenens W, Bayer-Santos E, Matsuyama BY, Bueno NF, dos Santos TR, Alvarez-Martinez CE, Salinas RK, Farah CS. Bacteria-Killing Type IV Secretion Systems. Front Microbiol 2019; 10:1078. [PMID: 31164878 PMCID: PMC6536674 DOI: 10.3389/fmicb.2019.01078] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [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: 03/15/2019] [Accepted: 04/29/2019] [Indexed: 01/25/2023] Open
Abstract
Bacteria have been constantly competing for nutrients and space for billions of years. During this time, they have evolved many different molecular mechanisms by which to secrete proteinaceous effectors in order to manipulate and often kill rival bacterial and eukaryotic cells. These processes often employ large multimeric transmembrane nanomachines that have been classified as types I-IX secretion systems. One of the most evolutionarily versatile are the Type IV secretion systems (T4SSs), which have been shown to be able to secrete macromolecules directly into both eukaryotic and prokaryotic cells. Until recently, examples of T4SS-mediated macromolecule transfer from one bacterium to another was restricted to protein-DNA complexes during bacterial conjugation. This view changed when it was shown by our group that many Xanthomonas species carry a T4SS that is specialized to transfer toxic bacterial effectors into rival bacterial cells, resulting in cell death. This review will focus on this special subtype of T4SS by describing its distinguishing features, similar systems in other proteobacterial genomes, and the nature of the effectors secreted by these systems and their cognate inhibitors.
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Affiliation(s)
- Germán G. Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Gabriel U. Oka
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Diorge P. Souza
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - William Cenens
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Ethel Bayer-Santos
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Bruno Y. Matsuyama
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Natalia F. Bueno
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | | | - Cristina E. Alvarez-Martinez
- Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, University of Campinas (UNICAMP), Campinas, Brazil
| | - Roberto K. Salinas
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Chuck S. Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
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Sgro GG, Costa TRD, Cenens W, Souza DP, Cassago A, Coutinho de Oliveira L, Salinas RK, Portugal RV, Farah CS, Waksman G. Cryo-EM structure of the bacteria-killing type IV secretion system core complex from Xanthomonas citri. Nat Microbiol 2018; 3:1429-1440. [PMID: 30349081 PMCID: PMC6264810 DOI: 10.1038/s41564-018-0262-z] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 09/03/2018] [Indexed: 12/17/2022]
Abstract
Type IV secretion (T4S) systems form the most common and versatile class of secretion systems in bacteria, capable of injecting both proteins and DNAs into host cells. T4S systems are typically composed of 12 components that form two major assemblies: the inner membrane complex embedded in the inner membrane and the core complex embedded in both the inner and outer membranes. Here we present the 3.3 Å resolution cryo-electron microscopy model of the T4S system core complex from Xanthomonas citri, a phytopathogen that utilizes this system to kill bacterial competitors. An extensive mutational investigation was performed to probe the vast network of protein-protein interactions in this 1.13 MDa assembly. This structure expands our knowledge of the molecular details of T4S system organization, assembly and evolution.
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Affiliation(s)
- Germán G Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.,Institute of Structural and Molecular Biology at UCL and Birkbeck College, Department of Biological Sciences, Birkbeck College, London, UK
| | - Tiago R D Costa
- Institute of Structural and Molecular Biology at UCL and Birkbeck College, Department of Biological Sciences, Birkbeck College, London, UK.,MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, UK
| | - William Cenens
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Diorge P Souza
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.,MRC Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Alexandre Cassago
- Laboratório Nacional de Nanotecnologia (LNNano), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, Brazil
| | - Luciana Coutinho de Oliveira
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.,Department of Medicinal Chemistry, Université du Québec, INRS - Institut Armand-Frappier, Laval, Québec, Canada
| | - Roberto K Salinas
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Rodrigo V Portugal
- Laboratório Nacional de Nanotecnologia (LNNano), Centro Nacional de Pesquisa em Energia e Materiais (CNPEM), Campinas, Brazil
| | - Chuck S Farah
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.
| | - Gabriel Waksman
- Institute of Structural and Molecular Biology at UCL and Birkbeck College, Department of Biological Sciences, Birkbeck College, London, UK. .,Institute of Structural and Molecular Biology at UCL and Birkbeck College, Research Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, UK.
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Abstract
Recent advances in cryo-electron microscopy (cryo-EM) have made it possible to solve structures of biological macromolecules at near atomic resolution. Development of more stable microscopes, improved direct electron detectors and faster software for image processing has enabled structural solution of not only large macromolecular (megadalton range) complexes but also small (~60 kDa) proteins. As a result of the widespread use of the technique, we have also witnessed new developments of techniques for cryo-EM grid preparation of membrane protein samples. This includes new types of solubilization strategies that better stabilize these protein complexes and the development of new grid supports with proven efficacy in reducing the motion of the molecules during electron beam exposure. Here, we discuss the practicalities and recent challenges of membrane protein sample preparation and vitrification, as well as grid support and foil treatment in the context of the structure determination of protein complexes by single particle cryo-EM.
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Affiliation(s)
- Germán G. Sgro
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - Tiago R. D. Costa
- Department of Life Sciences, Imperial College London, MRC Centre for Molecular Microbiology and Infection, London, United Kingdom
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Zimaro T, Thomas L, Marondedze C, Sgro GG, Garofalo CG, Ficarra FA, Gehring C, Ottado J, Gottig N. The type III protein secretion system contributes to Xanthomonas citri subsp. citri biofilm formation. BMC Microbiol 2014; 14:96. [PMID: 24742141 PMCID: PMC4021560 DOI: 10.1186/1471-2180-14-96] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 04/09/2014] [Indexed: 11/19/2022] Open
Abstract
Background Several bacterial plant pathogens colonize their hosts through the secretion of effector proteins by a Type III protein secretion system (T3SS). The role of T3SS in bacterial pathogenesis is well established but whether this system is involved in multicellular processes, such as bacterial biofilm formation has not been elucidated. Here, the phytopathogen Xanthomonas citri subsp. citri (X. citri) was used as a model to gain further insights about the role of the T3SS in biofilm formation. Results The capacity of biofilm formation of different X. citri T3SS mutants was compared to the wild type strain and it was observed that this secretion system was necessary for this process. Moreover, the T3SS mutants adhered proficiently to leaf surfaces but were impaired in leaf-associated growth. A proteomic study of biofilm cells showed that the lack of the T3SS causes changes in the expression of proteins involved in metabolic processes, energy generation, exopolysaccharide (EPS) production and bacterial motility as well as outer membrane proteins. Furthermore, EPS production and bacterial motility were also altered in the T3SS mutants. Conclusions Our results indicate a novel role for T3SS in X. citri in the modulation of biofilm formation. Since this process increases X. citri virulence, this study reveals new functions of T3SS in pathogenesis.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Natalia Gottig
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas (IBR-CONICET) and Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Ocampo y Esmeralda, Rosario 2000, Argentina.
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Sgro GG, Ficarra FA, Dunger G, Scarpeci TE, Valle EM, Cortadi A, Orellano EG, Gottig N, Ottado J. Contribution of a harpin protein from Xanthomonas axonopodis pv. citri to pathogen virulence. Mol Plant Pathol 2012; 13:1047-59. [PMID: 22788999 PMCID: PMC6638867 DOI: 10.1111/j.1364-3703.2012.00814.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
Xanthomonas axonopodis pv. citri (Xac), the bacterium that causes citrus canker, contains a gene in the hrp [for hypersensitive response (HR) and pathogenicity] cluster that encodes a harpin protein called Hpa1. Hpa1 produced HR in the nonhost plants tobacco, pepper and Arabidopsis, whereas, in the host plant citrus, it elicited a weak defence response with no visible phenotype. Co-infiltrations of Xac with or without the recombinant Hpa1 protein in citrus leaves produced a larger number of cankers in the presence of the protein. To characterize the effect of Hpa1 during the disease, an XacΔhpa1 mutant was constructed, and infiltration of this mutant caused a smaller number of cankers. In addition, the lack of Hpa1 hindered bacterial aggregation both in solution and in planta. Analysis of citrus leaves infiltrated with Hpa1 revealed alterations in mesophyll morphology caused by the presence of cavitations and crystal idioblasts, suggesting the binding of the harpin to plant membranes and the elicitation of signalling cascades. Overall, these results suggest that, even though Hpa1 elicits the defence response in nonhost plants and, to a lesser extent, in host plants, its main roles in citrus canker are to alter leaf mesophyll structure and to aggregate bacterial cells, and thus increase virulence and pathogen fitness. We expressed the N-terminal and C-terminal regions and found that, although both regions elicited HR in nonhost plants, only the N-terminal region showed increased virulence and bacterial aggregation, supporting the role of this region of the protein as the main active domain.
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Affiliation(s)
- Germán G Sgro
- Instituto de Biología Molecular y Celular de Rosario, Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad Nacional de Rosario, Suipacha 531, (S2002LRK), Rosario, Argentina
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