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Gou L, Yang X, Yun J, Ma Z, Zheng X, Du H, Zhang D. Roles of the components of the cag-pathogenicity island encoded type IV secretion system in Helicobacter pylori. Future Microbiol 2024:1-15. [PMID: 39171625 DOI: 10.1080/17460913.2024.2383514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Accepted: 07/19/2024] [Indexed: 08/23/2024] Open
Abstract
The Helicobacter pylori (H. pylori) cytotoxin-associated gene pathogenicity island (cagPAI) encodes 31 genes that assemble the cag type IV secretion system (T4SS) apparatus, which includes structures such as the outer membrane core complex, periplasmic ring, inner membrane complex and bacterial hairs. These proteins interact with each other to inject CagA into the host gastric epithelium. There are also individual unique functions that help H. pylori interfere with host cellular pathways, modulate the immune response and colonize the host for a long time. However, the functions of some of the proteins remain unclear. This review summarizes what is known about the structure and function of these auxiliary components and discusses their role in H. pylori pathogenesis.
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Affiliation(s)
- Lingzhu Gou
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China
- Department of Gastroenterology, Key Laboratory of Digestive Diseases of Lanzhou University Second Hospital, Lanzhou, People's Republic of China
| | - Xiaoping Yang
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China
- Department of Gastroenterology, Key Laboratory of Digestive Diseases of Lanzhou University Second Hospital, Lanzhou, People's Republic of China
| | - Jianwei Yun
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China
| | - Zenghui Ma
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China
- Department of Gastroenterology, Key Laboratory of Digestive Diseases of Lanzhou University Second Hospital, Lanzhou, People's Republic of China
| | - Xiaofeng Zheng
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China
| | - Hongwei Du
- Department of Gastroenterology, The Second People's Hospital of Lanzhou City, Lanzhou, People's Republic of China
| | - Dekui Zhang
- Department of Gastroenterology, Lanzhou University Second Hospital, Lanzhou, People's Republic of China
- Department of Gastroenterology, Key Laboratory of Digestive Diseases of Lanzhou University Second Hospital, Lanzhou, People's Republic of China
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Costa TRD, Patkowski JB, Macé K, Christie PJ, Waksman G. Structural and functional diversity of type IV secretion systems. Nat Rev Microbiol 2024; 22:170-185. [PMID: 37814112 PMCID: PMC11290344 DOI: 10.1038/s41579-023-00974-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/13/2023] [Indexed: 10/11/2023]
Abstract
Considerable progress has been made in recent years in the structural and molecular biology of type IV secretion systems in Gram-negative bacteria. The latest advances have substantially improved our understanding of the mechanisms underlying the recruitment and delivery of DNA and protein substrates to the extracellular environment or target cells. In this Review, we aim to summarize these exciting structural and molecular biology findings and to discuss their functional implications for substrate recognition, recruitment and translocation, as well as the biogenesis of extracellular pili. We also describe adaptations necessary for deploying a breadth of processes, such as bacterial survival, host-pathogen interactions and biotic and abiotic adhesion. We highlight the functional and structural diversity that allows this extremely versatile secretion superfamily to function under different environmental conditions and in different bacterial species. Additionally, we emphasize the importance of further understanding the mechanism of type IV secretion, which will support us in combating antimicrobial resistance and treating type IV secretion system-related infections.
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Affiliation(s)
- Tiago R D Costa
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College, London, UK.
| | - Jonasz B Patkowski
- Centre for Bacterial Resistance Biology, Department of Life Sciences, Imperial College, London, UK
| | - Kévin Macé
- Institute of Structural and Molecular Biology, Birkbeck and UCL, London, UK
- Institut de Génétique et Développement de Rennes (IGDR), Université de Rennes and CNRS, Rennes, France
| | - Peter J Christie
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, TX, USA.
| | - Gabriel Waksman
- Institute of Structural and Molecular Biology, Birkbeck and UCL, London, UK.
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Tran SC, Bryant KN, Cover TL. The Helicobacter pylori cag pathogenicity island as a determinant of gastric cancer risk. Gut Microbes 2024; 16:2314201. [PMID: 38391242 PMCID: PMC10896142 DOI: 10.1080/19490976.2024.2314201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Accepted: 01/31/2024] [Indexed: 02/24/2024] Open
Abstract
Helicobacter pylori strains can be broadly classified into two groups based on whether they contain or lack a chromosomal region known as the cag pathogenicity island (cag PAI). Colonization of the human stomach with cag PAI-positive strains is associated with an increased risk of gastric cancer and peptic ulcer disease, compared to colonization with cag PAI-negative strains. The cag PAI encodes a secreted effector protein (CagA) and components of a type IV secretion system (Cag T4SS) that delivers CagA and non-protein substrates into host cells. Animal model experiments indicate that CagA and the Cag T4SS stimulate a gastric mucosal inflammatory response and contribute to the development of gastric cancer. In this review, we discuss recent studies defining structural and functional features of CagA and the Cag T4SS and mechanisms by which H. pylori strains containing the cag PAI promote the development of gastric cancer and peptic ulcer disease.
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Affiliation(s)
- Sirena C. Tran
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Kaeli N. Bryant
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Timothy L. Cover
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Veterans Affairs Tennessee Valley Healthcare System, Nashville, TN, USA
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Motamedi H, Abiri R, Salari F, Jalili C, Alvandi A. Reduction of UreB and CagA expression level by siRNA construct in Helicobacter pylori strain SS1. BMC Microbiol 2023; 23:401. [PMID: 38114907 PMCID: PMC10729366 DOI: 10.1186/s12866-023-03143-x] [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: 06/05/2023] [Accepted: 12/05/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Two important virulence factors, urease and cagA, play an important role in Helicobacter pylori (H. pylori) gastric cancer. Aim of this study was to investigate the expression level and function of ureB and cagA using small interfering RNAs (siRNA). METHODS SS1 strain of H. pylori was considered as host for natural transformation. siRNA designed for ureB and cagA genes were inserted in pGPU6/GFP/Neo siRNA plasmid vector to evaluate using phenotypic and genotypic approaches. Then, qPCR was performed for determining inhibition rate of ureB and cagA gene expression. RESULTS The expression levels of siRNA-ureB and siRNA-cagA in the recombinant strain SS1 were reduced by about 5000 and 1000 fold, respectively, compared to the native H. pylori strain SS1. Also, preliminary evaluation of siRNA-ureB in vitro showed inhibition of urea enzyme activity. These data suggest that siRNA may be a powerful new tool for gene silencing in vitro, and for the development of RNAi-based anti-H. pylori therapies. CONCLUSION Our results show that targeting ureB and cagA genes with siRNA seems to be a new strategy to inhibit urease enzyme activity, reduce inflammation and colonization rate.
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Affiliation(s)
- Hamid Motamedi
- Department of Microbiology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
- Student Research Committee, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Ramin Abiri
- Fertility and Infertility Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Farhad Salari
- Department of Immunology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Cyrus Jalili
- Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Amirhoushang Alvandi
- Medical Technology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
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Yadav M, Sarkar S, Olymon K, Ray SK, Kumar A. Combined In Silico and In Vitro Study to Reveal the Structural Insights and Nucleotide-Binding Ability of the Transcriptional Regulator PehR from the Phytopathogen Ralstonia solanacearum. ACS OMEGA 2023; 8:34499-34515. [PMID: 37779998 PMCID: PMC10535256 DOI: 10.1021/acsomega.3c03175] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/05/2023] [Indexed: 10/03/2023]
Abstract
The transcriptional regulator PehR regulates the synthesis of the extracellular plant cell wall-degrading enzyme polygalacturonase, which is essential in the bacterial wilt of plants caused by one of the most devastating plant phytopathogens, Ralstonia solanacearum. The bacterium has a wide global distribution infecting many different plant species, resulting in massive agricultural and economic losses. Because the PehR molecular structure has not yet been determined and the structural consequences of PehR on ligand binding have not been thoroughly investigated, we have used an in silico approach combined with in vitro experiments for the first time to characterize the PehR regulator from a local isolate (Tezpur, Assam, India) of the phytopathogenic bacterium R. solanacearum F1C1. In this study, an in silico approach was employed to model the 3D structure of the PehR regulator, followed by the binding analysis of different ligands against this regulatory protein. Molecular docking studies suggest that ATP has the highest binding affinity for the PehR regulator. By using molecular dynamics (MD) simulation analysis, involving root-mean-square deviation, root-mean-square fluctuations, hydrogen bonding, radius of gyration, solvent-accessible surface area, and principal component analysis, it was possible to confirm the sudden conformational changes of the PehR regulator caused by the presence of ATP. We used an in vitro approach to further validate the formation of the PehR-ATP complex. In this approach, recombinant DNA technology was used to clone, express, and purify the gene encoding the PehR regulator from R. solanacearum F1C1. Purified PehR was used in ATP-binding experiments using fluorescence spectroscopy and Fourier transform infrared spectroscopy, the outcomes of which showed a potent binding to ATP. The putative PehR-ATP-binding analysis revealed the importance of the amino acids Lys190, Glu191, Arg192, Arg375, and Asp378 for the ATP-binding process, but further study is required to confirm this. It will be simpler to comprehend the catalytic mechanisms of a crucial PehR regulator process in R. solanacearum with the aid of the ATP-binding process hints provided by these structural biology applications.
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Affiliation(s)
- Mohit Yadav
- Department
of Molecular Biology and Biotechnology, Tezpur University, Napaam 784028, Assam, India
| | - Sharmilee Sarkar
- Department
of Molecular Biology and Biotechnology, Tezpur University, Napaam 784028, Assam, India
| | - Kaushika Olymon
- Department
of Molecular Biology and Biotechnology, Tezpur University, Napaam 784028, Assam, India
| | - Suvendra Kumar Ray
- Department
of Molecular Biology and Biotechnology, Tezpur University, Napaam 784028, Assam, India
| | - Aditya Kumar
- Department
of Molecular Biology and Biotechnology, Tezpur University, Napaam 784028, Assam, India
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