1
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Åberg A, Gideonsson P, Bhat A, Ghosh P, Arnqvist A. Molecular insights into the fine-tuning of pH-dependent ArsR-mediated regulation of the SabA adhesin in Helicobacter pylori. Nucleic Acids Res 2024; 52:5572-5595. [PMID: 38499492 PMCID: PMC11162790 DOI: 10.1093/nar/gkae188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 02/28/2024] [Accepted: 03/12/2024] [Indexed: 03/20/2024] Open
Abstract
Adaptation to variations in pH is crucial for the ability of Helicobacter pylori to persist in the human stomach. The acid responsive two-component system ArsRS, constitutes the global regulon that responds to acidic conditions, but molecular details of how transcription is affected by the ArsR response regulator remains poorly understood. Using a combination of DNA-binding studies, in vitro transcription assays, and H. pylori mutants, we demonstrate that phosphorylated ArsR (ArsR-P) forms an active protein complex that binds DNA with high specificity in order to affect transcription. Our data showed that DNA topology is key for DNA binding. We found that AT-rich DNA sequences direct ArsR-P to specific sites and that DNA-bending proteins are important for the effect of ArsR-P on transcription regulation. The repression of sabA transcription is mediated by ArsR-P with the support of Hup and is affected by simple sequence repeats located upstream of the sabA promoter. Here stochastic events clearly contribute to the fine-tuning of pH-dependent gene regulation. Our results reveal important molecular aspects for how ArsR-P acts to repress transcription in response to acidic conditions. Such transcriptional control likely mediates shifts in bacterial positioning in the gastric mucus layer.
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Affiliation(s)
- Anna Åberg
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Pär Gideonsson
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Abhayprasad Bhat
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Prachetash Ghosh
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Anna Arnqvist
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
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2
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Beard S, Moya-Beltrán A, Silva-García D, Valenzuela C, Pérez-Acle T, Loyola A, Quatrini R. Pangenome-level analysis of nucleoid-associated proteins in the Acidithiobacillia class: insights into their functional roles in mobile genetic elements biology. Front Microbiol 2023; 14:1271138. [PMID: 37817747 PMCID: PMC10561277 DOI: 10.3389/fmicb.2023.1271138] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 09/01/2023] [Indexed: 10/12/2023] Open
Abstract
Mobile genetic elements (MGEs) are relevant agents in bacterial adaptation and evolutionary diversification. Stable appropriation of these DNA elements depends on host factors, among which are the nucleoid-associated proteins (NAPs). NAPs are highly abundant proteins that bind and bend DNA, altering its topology and folding, thus affecting all known cellular DNA processes from replication to expression. Even though NAP coding genes are found in most prokaryotic genomes, their functions in host chromosome biology and xenogeneic silencing are only known for a few NAP families. Less is known about the occurrence, abundance, and roles of MGE-encoded NAPs in foreign elements establishment and mobility. In this study, we used a combination of comparative genomics and phylogenetic strategies to gain insights into the diversity, distribution, and functional roles of NAPs within the class Acidithiobacillia with a special focus on their role in MGE biology. Acidithiobacillia class members are aerobic, chemolithoautotrophic, acidophilic sulfur-oxidizers, encompassing substantial genotypic diversity attributable to MGEs. Our search for NAP protein families (PFs) in more than 90 genomes of the different species that conform the class, revealed the presence of 1,197 proteins pertaining to 12 different NAP families, with differential occurrence and conservation across species. Pangenome-level analysis revealed 6 core NAP PFs that were highly conserved across the class, some of which also existed as variant forms of scattered occurrence, in addition to NAPs of taxa-restricted distribution. Core NAPs identified are reckoned as essential based on the conservation of genomic context and phylogenetic signals. In turn, various highly diversified NAPs pertaining to the flexible gene complement of the class, were found to be encoded in known plasmids or, larger integrated MGEs or, present in genomic loci associated with MGE-hallmark genes, pointing to their role in the stabilization/maintenance of these elements in strains and species with larger genomes. Both core and flexible NAPs identified proved valuable as markers, the former accurately recapitulating the phylogeny of the class, and the later, as seed in the bioinformatic identification of novel episomal and integrated mobile elements.
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Affiliation(s)
- Simón Beard
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Ana Moya-Beltrán
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Santiago, Chile
| | - Danitza Silva-García
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
| | - Cesar Valenzuela
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
| | - Tomás Pérez-Acle
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
- Facultad de Ingeniería, Arquitectura y Diseño, Universidad San Sebastián, Santiago, Chile
| | - Alejandra Loyola
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
| | - Raquel Quatrini
- Centro Científico y Tecnológico de Excelencia Ciencia & Vida, Fundación Ciencia & Vida, Santiago, Chile
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Chile
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3
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Alves LDF, Bortolucci J, Reginato V, Guazzaroni ME, Mussatto SI. Improving Saccharomyces cerevisiae acid and oxidative stress resistance using a prokaryotic gene identified by functional metagenomics. Heliyon 2023; 9:e14838. [PMID: 37077683 PMCID: PMC10106912 DOI: 10.1016/j.heliyon.2023.e14838] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 04/21/2023] Open
Abstract
Innovations in obtaining products from lignocellulosic biomass have been largely based on the improvement of microorganisms and enzymes capable of degrading these materials. To complete the whole process, microorganisms must be able to ferment the resulting sugars and tolerate high concentrations of product, osmotic pressure, ion toxicity, temperature, toxic compounds from lignocellulose pretreatment, low pH, and oxidative stress. In this work, we engineered laboratory and industrial Saccharomyces cerevisiae strains by combining a gene (hu) recovered from a metagenomic approach with different native and synthetic promoters to obtain improved acid and oxidative stress resistance. Laboratorial strains harboring hu gene under the control of the synthetic stress responsive PCCW14v5 showed increased survival rates after 2 h exposure to pH 1.5. The hu gene was also able to significantly enhance the tolerance of the industrial strain to high concentrations of H2O2 when combined with PTEF1, PYGP1 or PYGP1v7 after 3 h exposure.
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Affiliation(s)
- Luana de Fátima Alves
- Department of Biology, Faculdade de Filosofia, University of São Paulo, Ciências e Letras de Ribeirão Preto, Ribeirão Preto, 14040-901, São Paulo, Brazil
- Department of Biochemistry, Faculdade de Medicina de Ribeirão Preto, University of São Paulo, Ribeirão Preto, 14040-900, São Paulo, Brazil
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Building 220, 2800, Kongens Lyngby, Denmark
| | - Jonatã Bortolucci
- Department of Biology, Faculdade de Filosofia, University of São Paulo, Ciências e Letras de Ribeirão Preto, Ribeirão Preto, 14040-901, São Paulo, Brazil
| | - Valeria Reginato
- Department of Biology, Faculdade de Filosofia, University of São Paulo, Ciências e Letras de Ribeirão Preto, Ribeirão Preto, 14040-901, São Paulo, Brazil
| | - María-Eugenia Guazzaroni
- Department of Biology, Faculdade de Filosofia, University of São Paulo, Ciências e Letras de Ribeirão Preto, Ribeirão Preto, 14040-901, São Paulo, Brazil
| | - Solange I. Mussatto
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 223, 2800, Kongens Lyngby, Denmark
- Corresponding author.
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4
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Insights into the Orchestration of Gene Transcription Regulators in Helicobacter pylori. Int J Mol Sci 2022; 23:ijms232213688. [PMID: 36430169 PMCID: PMC9696931 DOI: 10.3390/ijms232213688] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 10/31/2022] [Accepted: 11/04/2022] [Indexed: 11/09/2022] Open
Abstract
Bacterial pathogens employ a general strategy to overcome host defenses by coordinating the virulence gene expression using dedicated regulatory systems that could raise intricate networks. During the last twenty years, many studies of Helicobacter pylori, a human pathogen responsible for various stomach diseases, have mainly focused on elucidating the mechanisms and functions of virulence factors. In parallel, numerous studies have focused on the molecular mechanisms that regulate gene transcription to attempt to understand the physiological changes of the bacterium during infection and adaptation to the environmental conditions it encounters. The number of regulatory proteins deduced from the genome sequence analyses responsible for the correct orchestration of gene transcription appears limited to 14 regulators and three sigma factors. Furthermore, evidence is accumulating for new and complex circuits regulating gene transcription and H. pylori virulence. Here, we focus on the molecular mechanisms used by H. pylori to control gene transcription as a function of the principal environmental changes.
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5
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Agarwal N, Nagar N, Raj R, Kumar D, Poluri KM. Conserved Apical Proline Regulating the Structure and DNA Binding Properties of Helicobacter pylori Histone-like DNA Binding Protein (Hup). ACS OMEGA 2022; 7:15231-15246. [PMID: 35572751 PMCID: PMC9089689 DOI: 10.1021/acsomega.2c01754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 04/06/2022] [Indexed: 06/15/2023]
Abstract
Prokaryotic cells lack a proper dedicated nuclear arrangement machinery. A set of proteins known as nucleoid associated proteins (NAPs) perform opening and closure of nucleic acids, behest cellular requirement. Among these, a special class of proteins analogous to eukaryotic histones popularly known as histone-like (HU) DNA binding proteins facilitate the nucleic acid folding/compaction thereby regulating gene architecture and gene regulation. DNA compaction and DNA protection in Helicobacter pylori is performed by HU protein (Hup). To dissect and galvanize the role of proline residue in the binding of Hup with DNA, the structure-dynamics-functional relationship of Hup-P64A variant was analyzed. NMR and biophysical studies evidenced that Hup-P64A protein attenuated DNA-binding and induced structural/stability changes in the DNA binding domain (DBD). Moreover, molecular dynamics simulations and 15N relaxation studies established the reduced conformational dynamics of P64A protein. This comprehensive study dissected the exclusive role of evolutionarily conserved apical proline residue in regulating the structure and DNA binding of Hup protein as P64 is presumed to be involved in the external leverage mechanism responsible for DNA bending and packaging, as proline rings wedge into the DNA backbone through intercalation besides their significant role in DNA binding.
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Affiliation(s)
- Nipanshu Agarwal
- Department
of Biosciences and Bioengineering, Indian
Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
| | - Nupur Nagar
- Department
of Biosciences and Bioengineering, Indian
Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
| | - Ritu Raj
- Centre
of Biomedical Research, SGPGIMS Campus, Lucknow-226014, India
| | - Dinesh Kumar
- Centre
of Biomedical Research, SGPGIMS Campus, Lucknow-226014, India
| | - Krishna Mohan Poluri
- Department
of Biosciences and Bioengineering, Indian
Institute of Technology Roorkee, Roorkee-247667, Uttarakhand, India
- Centre
for Nanotechnology, Indian Institute of
Technology Roorkee, Roorkee-247667, Uttarakhand, India
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6
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Maruyama H, Nambu T, Mashimo C, Okinaga T, Takeyasu K. Single-Molecule/Cell Analyses Reveal Principles of Genome-Folding Mechanisms in the Three Domains of Life. Int J Mol Sci 2021; 22:13432. [PMID: 34948225 PMCID: PMC8707338 DOI: 10.3390/ijms222413432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 12/06/2021] [Accepted: 12/10/2021] [Indexed: 11/21/2022] Open
Abstract
Comparative structural/molecular biology by single-molecule analyses combined with single-cell dissection, mass spectroscopy, and biochemical reconstitution have been powerful tools for elucidating the mechanisms underlying genome DNA folding. All genomes in the three domains of life undergo stepwise folding from DNA to 30-40 nm fibers. Major protein players are histone (Eukarya and Archaea), Alba (Archaea), and HU (Bacteria) for fundamental structural units of the genome. In Euryarchaeota, a major archaeal phylum, either histone or HTa (the bacterial HU homolog) were found to wrap DNA. This finding divides archaea into two groups: those that use DNA-wrapping as the fundamental step in genome folding and those that do not. Archaeal transcription factor-like protein TrmBL2 has been suggested to be involved in genome folding and repression of horizontally acquired genes, similar to bacterial H-NS protein. Evolutionarily divergent SMC proteins contribute to the establishment of higher-order structures. Recent results are presented, including the use of Hi-C technology to reveal that archaeal SMC proteins are involved in higher-order genome folding, and the use of single-molecule tracking to reveal the detailed functions of bacterial and eukaryotic SMC proteins. Here, we highlight the similarities and differences in the DNA-folding mechanisms in the three domains of life.
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Affiliation(s)
- Hugo Maruyama
- Department of Bacteriology, Osaka Dental University, Hirakata 573-1121, Japan; (T.N.); (C.M.); (T.O.)
| | - Takayuki Nambu
- Department of Bacteriology, Osaka Dental University, Hirakata 573-1121, Japan; (T.N.); (C.M.); (T.O.)
| | - Chiho Mashimo
- Department of Bacteriology, Osaka Dental University, Hirakata 573-1121, Japan; (T.N.); (C.M.); (T.O.)
| | - Toshinori Okinaga
- Department of Bacteriology, Osaka Dental University, Hirakata 573-1121, Japan; (T.N.); (C.M.); (T.O.)
| | - Kunio Takeyasu
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan;
- Center for Biotechnology, National Taiwan University, Taipei 10672, Taiwan
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7
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Agarwal N, Jaiswal N, Gulati K, Gangele K, Nagar N, Kumar D, Poluri KM. Molecular Insights into Conformational Heterogeneity and Enhanced Structural Integrity of Helicobacter pylori DNA Binding Protein Hup at Low pH. Biochemistry 2021; 60:3236-3252. [PMID: 34665609 DOI: 10.1021/acs.biochem.1c00395] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The summarized amalgam of internal relaxation modulations and external forces like pH, temperature, and solvent conditions determine the protein structure, stability, and function. In a free-energy landscape, although conformers are arranged in vertical hierarchy, there exist several adjacent parallel sets with conformers occupying equivalent energy cleft. Such conformational states are pre-requisites for the functioning of proteins that have oscillating environmental conditions. As these conformational changes have utterly small re-arrangements, nuclear magnetic resonance (NMR) spectroscopy is unique in elucidating the structure-dynamics-stability-function relationships for such conformations. Helicobacter pylori survives and causes gastric cancer at extremely low pH also. However, least is known as to how the genome of the pathogen is protected from reactive oxygen species (ROS) scavenging in the gut at low pH under acidic stress. In the current study, biophysical characteristics of H. pylori DNA binding protein (Hup) have been elucidated at pH 2 using a combination of circular dichroism, fluorescence, NMR spectroscopy, and molecular dynamics simulations. Interestingly, the protein was found to have conserved structural features, differential backbone dynamics, enhanced stability, and DNA binding ability at low pH as well. In summary, the study suggests the partaking of Hup protein even at low pH in DNA protection for maintaining the genome integrity.
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Affiliation(s)
- Nipanshu Agarwal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand, India
| | - Nancy Jaiswal
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow 226014, India
| | - Khushboo Gulati
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand, India
| | - Krishnakant Gangele
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand, India
| | - Nupur Nagar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand, India
| | - Dinesh Kumar
- Centre of Biomedical Research, SGPGIMS Campus, Lucknow 226014, India
| | - Krishna Mohan Poluri
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand, India.,Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand, India
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8
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Gene Expression Analysis by Reverse Transcription Quantitative PCR. Methods Mol Biol 2021. [PMID: 33765310 DOI: 10.1007/978-1-0716-1302-3_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2023]
Abstract
The reverse transcription quantitative polymerase chain reaction (RT-qPCR) is a rapid detection technology that allows the amplification and quantification of specific RNA transcripts. RT-qPCR has increasingly been adopted for the detection and quantification of H. pylori across a range of sample types and applications. In addition, it is widely used to monitor host gene expression in cells and tissues in response to H. pylori infection . Outlined here is a two-step protocol that can be employed to analyze gene expression in H. pylori or H. pylori-infected samples.
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9
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Raj R, Agarwal N, Raghavan S, Chakraborti T, Poluri KM, Pande G, Kumar D. Epigallocatechin Gallate with Potent Anti- Helicobacter pylori Activity Binds Efficiently to Its Histone-like DNA Binding Protein. ACS OMEGA 2021; 6:3548-3570. [PMID: 33585739 PMCID: PMC7876696 DOI: 10.1021/acsomega.0c04763] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 01/21/2021] [Indexed: 05/10/2023]
Abstract
Helicobacter pylori (H. pylori)-a human gastric pathogen-forms a major risk factor for the development of various gastric pathologies such as chronic inflammatory gastritis, peptic ulcer, lymphomas of mucosa-associated lymphoid tissues, and gastric carcinoma. The complete eradication of infection is the primary objective of treating any H. pylori-associated gastric condition. However, declining eradication efficiencies, off-target effects, and patient noncompliance to prolong and broad-spectrum antibiotic treatments has spurred the clinical interest to search for alternative effective and safer therapeutic options. As natural compounds are safe and privileged with high levels of antibacterial-activity, previous studies have tested and reported a plethora of such compounds with potential in vitro/in vivo anti-H. pylori activity. However, the mode of action of majority of these natural compounds is unclear. The present study has been envisaged to compile the information of various such natural compounds and to evaluate their binding with histone-like DNA-binding proteins of H. pylori (referred here as Hup) using in silico molecular docking-based virtual screening experiments. Hup-being a major nucleoid-associated protein expressed by H. pylori-plays a strategic role in its survival and persistent colonization under hostile stress conditions. The ligand with highest binding energy with Hup-that is, epigallocatechin-(-)gallate (EGCG)-was rationally selected for further computational and experimental testing. The best docking poses of EGCG with Hup were first evaluated for their solution stability using long run molecular dynamics simulations and then using fluorescence and nuclear magnetic resonance titration experiments which demonstrated that the binding of EGCG with Hup is fairly strong (the resultant apparent dissociation constant (k D) values were equal to 2.61 and 3.29 ± 0.42 μM, respectively).
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Affiliation(s)
- Ritu Raj
- Centre
of Biomedical Research (CBMR), SGPGIMS Campus, Raibareli Road, Lucknow 226014, Uttar Pradesh, India
- Department
of Biochemistry & Biophysics, University
of Kalyani, Kalyani 741235, West Bengal, India
| | - Nipanshu Agarwal
- Department
of Biotechnology and Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - Sriram Raghavan
- Computational
Structural Biology Team, RIKEN Center for
Computational Science (R-CCS), Kobe 650-0047, Japan
| | - Tapati Chakraborti
- Department
of Biochemistry & Biophysics, University
of Kalyani, Kalyani 741235, West Bengal, India
| | - Krishna Mohan Poluri
- Department
of Biotechnology and Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - Gaurav Pande
- Department
of Gastroeneterology, SGPGIMS, Lucknow 226014, Uttar Pradesh, India
- . Phone: +91-9170689999
| | - Dinesh Kumar
- Centre
of Biomedical Research (CBMR), SGPGIMS Campus, Raibareli Road, Lucknow 226014, Uttar Pradesh, India
- . Phone: +91-8953261506
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10
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Exquisite binding interaction of 18β-Glycyrrhetinic acid with histone like DNA binding protein of Helicobacter pylori: A computational and experimental study. Int J Biol Macromol 2020; 161:231-246. [DOI: 10.1016/j.ijbiomac.2020.06.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 06/04/2020] [Accepted: 06/04/2020] [Indexed: 02/07/2023]
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11
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Kamashev DE, Rakitina TV, Matyushkina DS, Evsyutina DV, Vanyushkina AA, Agapova YK, Anisimova VE, Drobyshev AL, Butenko IO, Pobeguts OV, Fisunov GY. Proteome of HU-Lacking E. coli Studied by Means of 2D Gel Electrophoresis. RUSSIAN JOURNAL OF BIOORGANIC CHEMISTRY 2019. [DOI: 10.1134/s1068162019050029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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12
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Fagoonee S, Pellicano R. Helicobacter pylori: molecular basis for colonization and survival in gastric environment and resistance to antibiotics. A short review. Infect Dis (Lond) 2019; 51:399-408. [PMID: 30907202 DOI: 10.1080/23744235.2019.1588472] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/11/2019] [Accepted: 02/20/2019] [Indexed: 12/12/2022] Open
Abstract
Helicobacter pylori is a human-specific pathogen with a strict tropism for the gastric mucosa. This bacterium infects around half of the world population and is the main responsible for gastritis, peptic ulcer and, in some cases, for the pathogenesis of gastric cancer. Nevertheless, disease development in infected subjects depends not only on the bacterium, but also on the host genetic predisposition and on environmental factors. The fascinating question of how the bacterium can survive in the gastric environment has stimulated research in this field. It is now clear that H. pylori is able to colonize and adhere to the gastric epithelium through several mechanisms, including the breakdown of urea with production of the cell-toxic ammonia. The resulting raise in pH neutralizes acidity of the stomach, thereby allowing the bacterium to safely cross the mucus layer to the epithelial surface. Current challenges regard understanding the mechanisms of antibiotic resistance and how to overcome it. Lately, an increasing H. pylori resistance rate to antibiotics has been reported and several molecular bases for this phenomenon described. In this review, we highlight the current knowledge on mechanisms supporting H. pylori resistance to gastric environment and to therapy.
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Affiliation(s)
- Sharmila Fagoonee
- a Institute for Biostructure and Bioimaging (CNR) c/o Molecular Biotechnology Center , Turin , Italy
| | - Rinaldo Pellicano
- b Unit of Gastroenterology , Molinette-SGAS Hospital , Turin , Italy
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13
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Oliveira Paiva AM, Friggen AH, Qin L, Douwes R, Dame RT, Smits WK. The Bacterial Chromatin Protein HupA Can Remodel DNA and Associates with the Nucleoid in Clostridium difficile. J Mol Biol 2019; 431:653-672. [PMID: 30633871 DOI: 10.1016/j.jmb.2019.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 12/19/2018] [Accepted: 01/02/2019] [Indexed: 12/15/2022]
Abstract
The maintenance and organization of the chromosome plays an important role in the development and survival of bacteria. Bacterial chromatin proteins are architectural proteins that bind DNA and modulate its conformation, and by doing so affect a variety of cellular processes. No bacterial chromatin proteins of Clostridium difficile have been characterized to date. Here, we investigate aspects of the C. difficile HupA protein, a homologue of the histone-like HU proteins of Escherichia coli. HupA is a 10-kDa protein that is present as a homodimer in vitro and self-interacts in vivo. HupA co-localizes with the nucleoid of C. difficile. It binds to the DNA without a preference for the DNA G + C content. Upon DNA binding, HupA induces a conformational change in the substrate DNA in vitro and leads to compaction of the chromosome in vivo. The present study is the first to characterize a bacterial chromatin protein in C. difficile and opens the way to study the role of chromosomal organization in DNA metabolism and on other cellular processes in this organism.
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Affiliation(s)
- Ana M Oliveira Paiva
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands
| | - Annemieke H Friggen
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands
| | - Liang Qin
- Faculty of Science, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands
| | - Roxanne Douwes
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, the Netherlands
| | - Remus T Dame
- Faculty of Science, Leiden Institute of Chemistry, Leiden University, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands
| | - Wiep Klaas Smits
- Department of Medical Microbiology, Section Experimental Bacteriology, Leiden University Medical Center, Leiden, the Netherlands; Center for Microbial Cell Biology, Leiden, the Netherlands.
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14
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Abstract
In this review, we highlight progress in the last year in characterizing known virulence factors like flagella and the Cag type IV secretion system with sophisticated structural and biochemical approaches to yield new insight on the assembly and functions of these critical virulence determinants. Several aspects of Helicobacter pylori physiology were newly explored this year and evaluated for their functions during stomach colonization, including a fascinating role for the essential protease HtrA in allowing access of H. pylori to the basolateral side of the gastric epithelium through cleavage of the tight junction protein E-cadherin to facilitate CagA delivery. Molecular biology tools standard in model bacteria, including regulated gene expression during animal infection and fluorescent reporter gene fusions, were newly applied to H. pylori to explore functions for urease beyond initial colonization and establish high salt consumption as a mediator of gene expression changes. New sequencing technologies enabled validation of long postulated roles for DNA methylation in regulating H. pylori gene expression. On the cell biology side, elegant work using lineage tracing in the murine model and organoid primary cell culture systems has provided new insights into how H. pylori manipulates gastric tissue functions, locally and at a distance, to promote its survival in the stomach and induce pathologic changes. Finally, new work has bolstered the case for genomic variation as an important mechanism to generate phenotypic diversity during changing environmental conditions in the context of diet manipulation in animal infection models and during human experimental infection after vaccination.
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Affiliation(s)
- Langgeng Agung Waskito
- Faculty of Medicine, Department of Environmental and Preventive Medicine, Oita University, Yufu-City, Oita, Japan.,Institute of Tropical Disease, Universitas Airlangga, Surabaya, Indonesia
| | - Nina R Salama
- Human Biology Division, Fred Hutchinson Cancer Research Center, Seattle, Washington
| | - Yoshio Yamaoka
- Faculty of Medicine, Department of Environmental and Preventive Medicine, Oita University, Yufu-City, Oita, Japan.,Department of Medicine, Gastroenterology and Hepatology Section, Baylor College of Medicine, Houston, Texas
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15
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Abstract
Helicobacter pylori is responsible for the most commonly found infection in the world's population. It is the major risk factor for gastric cancer development. Numerous studies published over the last year provide new insights into the strategies employed by H. pylori to adapt to the extreme acidic conditions of the gastric environment, to establish persistent infection and to deregulate host functions, leading to gastric pathogenesis and cancer. In this review, we report recent data on the mechanisms involved in chemotaxis, on the essential role of nickel in acid resistance and gastric colonization, on the importance of adhesins and Hop proteins and on the role of CagPAI-components and CagA. Among the host functions, a special focus has been made on the escape from immune response, the ability of bacteria to induce genetic instability and modulate telomeres, the mechanism of autophagy and the deregulation of micro RNAs.
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Affiliation(s)
- Vania Camilo
- Pasteur Institute, Department of Microbiology, Helicobacter Pathogenesis Unit, Paris Cedex 15, France.,INSERM U1173, Faculty of Health Sciences Simone Veil, Université Versailles-Saint-Quentin, Saint Quentin en Yvelines, France
| | - Toshiro Sugiyama
- Graduate School of Medicine and Pharmaceutical Sciences, Department of Gastroenterology, University of Toyama, Sugitani, Toyama, Japan
| | - Eliette Touati
- Pasteur Institute, Department of Microbiology, Helicobacter Pathogenesis Unit, Paris Cedex 15, France
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