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Yu Y, Liang L, Sun T, Lu H, Yang P, Li J, Pang Q, Zeng J, Shi P, Li J, Lu Y. Micro/Nanomotor-Driven Intelligent Targeted Delivery Systems: Dynamics Sources and Frontier Applications. Adv Healthc Mater 2024:e2400163. [PMID: 39075811 DOI: 10.1002/adhm.202400163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 07/05/2024] [Indexed: 07/31/2024]
Abstract
Micro/nanomotors represent a promising class of drug delivery carriers capable of converting surrounding chemical or external energy into mechanical power, enabling autonomous movement. Their distinct autonomous propulsive force distinguishes them from other carriers, offering significant potential for enhancing drug penetration across cellular and tissue barriers. A comprehensive understanding of micro/nanomotor dynamics with various power sources is crucial to facilitate their transition from proof-of-concept to clinical application. In this review, micro/nanomotors are categorized into three classes based on their energy sources: endogenously stimulated, exogenously stimulated, and live cell-driven. The review summarizes the mechanisms governing micro/nanomotor movements under these energy sources and explores factors influencing autonomous motion. Furthermore, it discusses methods for controlling micro/nanomotor movement, encompassing aspects related to their structure, composition, and environmental factors. The remarkable propulsive force exhibited by micro/nanomotors makes them valuable for significant biomedical applications, including tumor therapy, bio-detection, bacterial infection therapy, inflammation therapy, gastrointestinal disease therapy, and environmental remediation. Finally, the review addresses the challenges and prospects for the application of micro/nanomotors. Overall, this review emphasizes the transformative potential of micro/nanomotors in overcoming biological barriers and enhancing therapeutic efficacy, highlighting their promising clinical applications across various biomedical fields.
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Affiliation(s)
- Yue Yu
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Ling Liang
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Ting Sun
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Haiying Lu
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Pushan Yang
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Jinrong Li
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Qinjiao Pang
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Jia Zeng
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Ping Shi
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
| | - Jianshu Li
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu, 610065, P. R. China
| | - Yongping Lu
- Guangyuan Central Hospital, Guangyuan, 628000, P. R. China
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Lyu C, Hu H, Cai L, He S, Xu X, Zhou G, Wang H. A trans-acting sRNA SaaS targeting hilD, cheA and csgA to inhibit biofilm formation of S. Enteritidis. J Adv Res 2024:S2090-1232(24)00232-7. [PMID: 38852803 DOI: 10.1016/j.jare.2024.06.008] [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: 04/03/2024] [Revised: 05/28/2024] [Accepted: 06/04/2024] [Indexed: 06/11/2024] Open
Abstract
INTRODUCTION Salmonella Enteritidis has brought great harm to public health, animal production and food safety worldwide. The biofilm formed by Salmonella Enteritidis plays a critical role in microbial cross-contamination. Small non-coding RNAs (sRNAs) have been demonstrated to be responsible for regulating the formation of biofilm. The sRNA SaaS has been identified previously, that promotes pathogenicity by regulating invasion and virulence factors. However, whether the SaaS is implicated in regulating biofilm formation in abiotic surfaces remains unclear. OBJECTIVES This study aimed to clarify the effect of SaaS in Salmonella Enteritidis and explore the modulatory mechanism on the biofilm formation. METHODS Motility characteristics and total biomass of biofilm of test strains were investigated by the phenotypes in three soft agar plates and crystal violet staining in polystyrene microplates. Studies of microscopic structure and extracellular polymeric substances (EPS) of biofilm on solid surfaces were carried out using confocal laser scanning microscope (CLSM) and Raman spectra. Transcriptomics and proteomics were applied to analyze the changes of gene expression and EPS component. The RNA-protein pull-down and promoter-reporter β-galactosidase activity assays were employed to analyze RNA binding proteins and identify target mRNAs, respectively. RESULTS SaaS inhibits biofilm formation by repressing the adhesion potential and the secretion of EPS components. Integration of transcriptomics and proteomics analysis revealed that SaaS strengthened the expression of the flagellar synthesis system and downregulated the expression of curli amyloid fibers. Furthermore, RNA-protein pull-down interactome datasets indicated that SaaS binds to Hfq (an RNA molecular chaperone protein, known as a host factor for phage Qbeta RNA replication) uniquely among 193 candidate proteins, and promoter-reporter β-galactosidase activity assay confirmed target mRNAs including hilD, cheA, and csgA. CONCLUSION SaaS inhibits the properties of bacterial mobility, perturbs the secretion of EPS, and contributes to the inhibition of biofilm formation by interacting with target mRNA (hilD, cheA, and csgA) through the Hfq-mediated pathway.
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Affiliation(s)
- Chongyang Lyu
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Haijing Hu
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Linlin Cai
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Shuwen He
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Xinglian Xu
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Guanghong Zhou
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China
| | - Huhu Wang
- State Key Laboratory of Meat Quality Control and Cultured Meat Development, College of Food Science and Technology, Nanjing Agricultural University, Nanjing, People's Republic of China; College of Food Science and Pharmacy, Xinjiang Agricultural University, Urumqi, Xinjiang, People's Republic of China.
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Bryant OJ, Fraser GM. Identification of a new export signal that targets early subunits to the flagellar type III secretion export machinery. mBio 2024; 15:e0306723. [PMID: 38376149 PMCID: PMC10936197 DOI: 10.1128/mbio.03067-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 01/26/2024] [Indexed: 02/21/2024] Open
Abstract
Type III secretion systems (T3SSs) are essential for motility and virulence in many bacterial pathogens. Proteins destined for the flagellar T3SS contain at least two export signals in their N-terminal D0 domain. Here, we describe a third carboxy (C)-terminal signal in early flagellar subunits that facilitates subunit targeting to the export machinery. Mutational analysis identified critical residues within the flagellar hook subunit C-terminal export signal. The flagellar ATPase and cytoplasmic ring components were not required for this targeting, indicating that core export machinery components facilitate substrate targeting via the C-terminal export signal. More broadly, these results demonstrate that multiple distinct export signals within type III secretion substrates facilitate distinct export events at the T3SS export machinery. Our data establish key events in the export mechanism of type III secretion systems: targeting of subunits to and their sequential interactions with key components of the export machinery. IMPORTANCE Many bacterial pathogens utilize T3SS to inject virulence proteins (effectors) into host cells or to assemble flagella on the bacterial cell surface. Bacterial flagella present a paradigm for how cells build and operate complex cell-surface "nanomachines." Efficient subunit targeting from the bacterial cytosol to type III secretion systems is essential for rapid assembly and secretion by T3SSs. Subunits are thought to dock at the export machinery before being unfolded and translocated into the export channel. However, little is known about how subunits dock at the export machinery and the events that occur post docking. Here, we identified a new export signal within the C-termini of subunits that is essential for targeting of subunits to the type III export machinery. We show that this new export signal and previously identified export signals are recognized separately and sequentially, revealing a pathway for subunit transit through the type III export machinery in which sequential recognition events carry out different roles at major steps in the export pathway.
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Affiliation(s)
- Owain J. Bryant
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, USA
| | - Gillian M. Fraser
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, United Kingdom
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4
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Kint N, Viollier PH. Extracellular transfer of a conserved polymerization factor for multi-flagellin filament assembly in Caulobacter. Cell Rep 2023; 42:112890. [PMID: 37515768 DOI: 10.1016/j.celrep.2023.112890] [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: 12/12/2022] [Revised: 06/15/2023] [Accepted: 07/12/2023] [Indexed: 07/31/2023] Open
Abstract
Unidirectional growth of filamentous protein assemblies including the bacterial flagellum relies on dedicated polymerization factors (PFs). The molecular determinants and structural transitions imposed by PFs on multi-subunit assembly are poorly understood. Here, we unveil FlaY from the polarized α-proteobacterium Caulobacter crescentus as a defining member of an alternative class of specialized flagellin PFs. Unlike the paradigmatic FliD capping protein, FlaY relies on a funnel-like β-propeller fold for flagellin polymerization. FlaY binds flagellin and is secreted by the flagellar secretion apparatus, yet it can also promote flagellin polymerization exogenously when donated from flagellin-deficient cells, serving as a transferable, extracellular public good. While the surge in FlaY abundance precedes bulk flagellin synthesis, FlaY-independent filament assembly is enhanced by mutation of a conserved region in multiple flagellin paralogs. We suggest that FlaYs are (multi-)flagellin PFs that evolved convergently to FliDs yet appropriated the versatile β-propeller fold implicated in human diseases for chaperone-assisted filament assembly.
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Affiliation(s)
- Nicolas Kint
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, Rue Michel Servet 1, 1211 Genève, Switzerland.
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, Rue Michel Servet 1, 1211 Genève, Switzerland.
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You Y, Ye F, Mao W, Yang H, Lai J, Deng S. An overview of the structure and function of the flagellar hook FlgE protein. World J Microbiol Biotechnol 2023; 39:126. [PMID: 36941455 DOI: 10.1007/s11274-023-03568-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/04/2023] [Indexed: 03/23/2023]
Abstract
The flagellum is an important organelle for the survival of bacteria and consists of a basal body, hook, and filament. The FlgE protein is the subunit of the hook that connects the basal body and the filament and determines the motility of bacteria. Also, flgE gene plays an essential role in flagellar biosynthesis, swimming ability and biofilm formation. Although the intact flagella and the major component filament have been extensively studied, so far, little is known about the comprehensive understanding of flagellar hook and FlgE. Here in this review, we summarize the structures of flagellar hook and its subunit FlgE in various species and physiological functions of FlgE, including the hook assembly, the structural characteristics of flagellar hook, the mechanical properties of hook, and the similarities and differences between FlgE (hook) and FlgG (distal rod), with special attention on the interaction of FlgE with other molecules, the antigenicity and pro-inflammatory effect of FlgE, and cross-linking of FlgE in spirochetes. We hope our summary of this review could provide a better understanding of the FlgE protein and provide some useful information for developing new effective antibacterial drugs in the future work.
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Affiliation(s)
- Yu You
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China.
| | - Fei Ye
- Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Wei Mao
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Hong Yang
- Biopharmaceutical Research Institute, West China Hospital, Sichuan University, Chengdu, 610041, China
| | - Jijia Lai
- Department of Laboratory Medicine, Hospital of Chengdu Office of People's Government of Tibetan Autonomous Region, Chengdu, 610041, China
| | - Shun Deng
- Sichuan Province Orthopedic Hospital, 132 West First Section First Ring Road, Chengdu, 610041, China
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Feng Z, Wang Y, Xu H, Guo Y, Xia W, Zhao C, Zhao X, Wu J. Recent advances in bacterial therapeutics based on sense and response. Acta Pharm Sin B 2022; 13:1014-1027. [PMID: 36970195 PMCID: PMC10031265 DOI: 10.1016/j.apsb.2022.09.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 06/26/2022] [Accepted: 08/18/2022] [Indexed: 11/18/2022] Open
Abstract
Intelligent drug delivery is a promising strategy for cancer therapies. In recent years, with the rapid development of synthetic biology, some properties of bacteria, such as gene operability, excellent tumor colonization ability, and host-independent structure, make them ideal intelligent drug carriers and have attracted extensive attention. By implanting condition-responsive elements or gene circuits into bacteria, they can synthesize or release drugs by sensing stimuli. Therefore, compared with traditional drug delivery, the usage of bacteria for drug loading has better targeting ability and controllability, and can cope with the complex delivery environment of the body to achieve the intelligent delivery of drugs. This review mainly introduces the development of bacterial-based drug delivery carriers, including mechanisms of bacterial targeting to tumor colonization, gene deletions or mutations, environment-responsive elements, and gene circuits. Meanwhile, we summarize the challenges and prospects faced by bacteria in clinical research, and hope to provide ideas for clinical translation.
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Affiliation(s)
- Zhuo Feng
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
| | - Yuchen Wang
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
| | - Haiheng Xu
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
| | - Yunfei Guo
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
| | - Wen Xia
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
| | - Chenxuan Zhao
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
| | - Xiaozhi Zhao
- Department of Andrology, Drum Tower Hospital, Medical School of Nanjing University, Nanjing 210093, China
- Corresponding authors. Tel.: +025 83592629.
| | - Jinhui Wu
- State Key Laboratory of Pharmaceutical Biotechnology, Chemistry and Biomedicine Innovation Center, Medical School of Nanjing University, Nanjing 210093, China
- Jiangsu Key Laboratory for Nano Technology, Nanjing University, Nanjing 210093, China
- Corresponding authors. Tel.: +025 83592629.
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7
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Mondino S, San Martin F, Buschiazzo A. 3D cryo-electron microscopic imaging of bacterial flagella: novel structural and mechanistic insights into cell motility. J Biol Chem 2022; 298:102105. [PMID: 35671822 PMCID: PMC9254593 DOI: 10.1016/j.jbc.2022.102105] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 10/26/2022] Open
Abstract
Bacterial flagella are nanomachines that enable cells to move at high speeds. Comprising ≳25 different types of proteins, the flagellum is a large supramolecular assembly organized into three widely conserved substructures: a basal body including the rotary motor, a connecting hook, and a long filament. The whole flagellum from Escherichia coli weighs ∼20 MDa, without considering its filament portion, which is by itself a ∼1.6 GDa structure arranged as a multimer of ∼30,000 flagellin protomers. Breakthroughs regarding flagellar structure and function have been achieved in the last few years, mainly due to the revolutionary improvements in 3D cryo-electron microscopy methods. This review discusses novel structures and mechanistic insights derived from such high-resolution studies, advancing our understanding of each one of the three major flagellar segments. The rotation mechanism of the motor has been unveiled with unprecedented detail, showing a two-cogwheel machine propelled by a Brownian ratchet device. Additionally, by imaging the flagellin-like protomers that make up the hook in its native bent configuration, their unexpected conformational plasticity challenges the paradigm of a two-state conformational rearrangement mechanism for flagellin-fold proteins. Finally, imaging of the filaments of periplasmic flagella, which endow Spirochete bacteria with their singular motility style, uncovered a strikingly asymmetric protein sheath that coats the flagellin core, challenging the view of filaments as simple homopolymeric structures that work as freely whirling whips. Further research will shed more light on the functional details of this amazing nanomachine, but our current understanding has definitely come a long way.
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Affiliation(s)
- Sonia Mondino
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay
| | - Fabiana San Martin
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay
| | - Alejandro Buschiazzo
- Laboratory of Molecular & Structural Microbiology, Institut Pasteur de Montevideo, Montevideo, Uruguay; Integrative Microbiology of Zoonotic Agents IMiZA Unit, Joint International Unit, Institut Pasteur/Institut Pasteur de Montevideo, France/Uruguay; Microbiology Department, Institut Pasteur, Paris, France.
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8
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Tan X, Dai X, Chen T, Wu Y, Yang D, Zheng Y, Chen H, Wan X, Yang Y. Complete Genome Sequence Analysis of Ralstonia solanacearum Strain PeaFJ1 Provides Insights Into Its Strong Virulence in Peanut Plants. Front Microbiol 2022; 13:830900. [PMID: 35273586 PMCID: PMC8904134 DOI: 10.3389/fmicb.2022.830900] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/12/2022] [Indexed: 11/22/2022] Open
Abstract
The bacterial wilt of peanut (Arachis hypogaea L.) caused by Ralstonia solanacearum is a devastating soil-borne disease that seriously restricted the world peanut production. However, the molecular mechanism of R. solanacearum–peanut interaction remains largely unknown. We found that R. solanacearum HA4-1 and PeaFJ1 isolated from peanut plants showed different pathogenicity by inoculating more than 110 cultivated peanuts. Phylogenetic tree analysis demonstrated that HA4-1 and PeaFJ1 both belonged to phylotype I and sequevar 14M, which indicates a high degree of genomic homology between them. Genomic sequencing and comparative genomic analysis of PeaFJ1 revealed 153 strain-specific genes compared with HA4-1. The PeaFJ1 strain-specific genes consisted of diverse virulence-related genes including LysR-type transcriptional regulators, two-component system-related genes, and genes contributing to motility and adhesion. In addition, the repertoire of the type III effectors of PeaFJ1 was bioinformatically compared with that of HA4-1 to find the candidate effectors responsible for their different virulences. There are 79 effectors in the PeaFJ1 genome, only 4 of which are different effectors compared with HA4-1, including RipS4, RipBB, RipBS, and RS_T3E_Hyp6. Based on the virulence profiles of the two strains against peanuts, we speculated that RipS4 and RipBB are candidate virulence effectors in PeaFJ1 while RipBS and RS_T3E_Hyp6 are avirulence effectors in HA4-1. In general, our research greatly reduced the scope of virulence-related genes and made it easier to find out the candidates that caused the difference in pathogenicity between the two strains. These results will help to reveal the molecular mechanism of peanut–R. solanacearum interaction and develop targeted control strategies in the future.
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Affiliation(s)
- Xiaodan Tan
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Xiaoqiu Dai
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Ting Chen
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yushuang Wu
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Dong Yang
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yixiong Zheng
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Huilan Chen
- Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Huazhong Agricultural University, Wuhan, China
| | - Xiaorong Wan
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Yong Yang
- Guangzhou Key Laboratory for Research and Development of Crop Germplasm Resources, Zhongkai University of Agriculture and Engineering, Guangzhou, China
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Bryant OJ, Dhillon P, Hughes C, Fraser GM. Recognition of discrete export signals in early flagellar subunits during bacterial Type III secretion. eLife 2022; 11:66264. [PMID: 35238774 PMCID: PMC8983047 DOI: 10.7554/elife.66264] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/02/2022] [Indexed: 11/13/2022] Open
Abstract
Type III Secretion Systems (T3SS) deliver subunits from the bacterial cytosol to nascent cell surface flagella. Early flagellar subunits that form the rod and hook substructures are unchaperoned and contain their own export signals. A gate recognition motif (GRM) docks them at the FlhBc component of the FlhAB-FliPQR export gate, but the gate must then be opened and subunits must be unfolded to pass through the flagellar channel. This induced us to seek further signals on the subunits. Here, we identify a second signal at the extreme N-terminus of flagellar rod and hook subunits and determine that key to the signal is its hydrophobicity. We show that the two export signal elements are recognised separately and sequentially, as the N-terminal signal is recognised by the flagellar export machinery only after subunits have docked at FlhBC via the GRM. The position of the N-terminal hydrophobic signal in the subunit sequence relative to the GRM appeared to be important, as a FlgD deletion variant (FlgDshort), in which the distance between the N-terminal signal and the GRM was shortened, 'stalled' at the export machinery and was not exported. The attenuation of motility caused by FlgDshort was suppressed by mutations that destabilised the closed conformation of the FlhAB-FliPQR export gate, suggesting that the hydrophobic N-terminal signal might trigger opening of the flagellar export gate.
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Affiliation(s)
- Owain J Bryant
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Paraminder Dhillon
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Colin Hughes
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Gillian M Fraser
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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10
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Leal-Morales A, Pulido-Sánchez M, López-Sánchez A, Govantes F. Transcriptional organization and regulation of the Pseudomonas putida flagellar system. Environ Microbiol 2021; 24:137-157. [PMID: 34859548 DOI: 10.1111/1462-2920.15857] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 01/22/2023]
Abstract
A single region of the Pseudomonas putida genome, designated the flagellar cluster, includes 59 genes potentially involved in the biogenesis and function of the flagellar system. Here, we combine bioinformatics and in vivo gene expression analyses to clarify the transcriptional organization and regulation of the flagellar genes in the cluster. We have identified 11 flagellar operons and characterized 22 primary and internal promoter regions. Our results indicate that synthesis of the flagellar apparatus and core chemotaxis machinery is regulated by a three-tier cascade in which fleQ is a Class I gene, standing at the top of the transcriptional hierarchy. FleQ- and σ54 -dependent Class II genes encode most components of the flagellar structure, part of the chemotaxis machinery and multiple regulatory elements, including the flagellar σ factor FliA. FliA activation of Class III genes enables synthesis of the filament, one stator complex and completion of the chemotaxis apparatus. Accessory regulatory proteins and an intricate operon architecture add complexity to the regulation by providing feedback and feed-forward loops to the main circuit. Because of the high conservation of the gene arrangement and promoter motifs, we believe that the regulatory circuit presented here may also apply to other environmental pseudomonads.
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Affiliation(s)
- Antonio Leal-Morales
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/Consejo Superior de Investigaciones Científicas/Junta de Andalucía and Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain
| | - Marta Pulido-Sánchez
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/Consejo Superior de Investigaciones Científicas/Junta de Andalucía and Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain
| | - Aroa López-Sánchez
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/Consejo Superior de Investigaciones Científicas/Junta de Andalucía and Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain
| | - Fernando Govantes
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide/Consejo Superior de Investigaciones Científicas/Junta de Andalucía and Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Sevilla, Spain
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11
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Bryant OJ, Fraser GM. Regulation of bacterial Type III Secretion System export gate opening by substrates and the FliJ stalk of the flagellar ATPase. FEBS J 2021; 289:2628-2641. [PMID: 34812581 DOI: 10.1111/febs.16294] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 09/13/2021] [Accepted: 11/22/2021] [Indexed: 01/12/2023]
Abstract
Type III Secretion Systems (T3SS) transport proteins from the bacterial cytosol for assembly into cell surface nanomachines or direct delivery into target eukaryotic cells. At the core of the flagellar T3SS, the FlhAB-FliPQR export gate regulates protein entry into the export channel whilst maintaining the integrity of the cell membrane. Here, we identify critical residues in the export gate FliR plug that stabilise the closed conformation, preserving the membrane permeability barrier, and we show that the gate opens and closes in response to export substrate availability. Our data indicate that FlhAB-FliPQR gate opening, which is triggered by substrate export signals, is energised by FlhA in a proton motive force-dependent manner. We present evidence that the export substrate and the FliJ stalk of the flagellar ATPase provide mechanistically distinct, non-redundant gate-activating signals that are critical for efficient export.
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12
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Lopes GV, Ramires T, Kleinubing NR, Scheik LK, Fiorentini ÂM, Padilha da Silva W. Virulence factors of foodborne pathogen Campylobacterjejuni. Microb Pathog 2021; 161:105265. [PMID: 34699927 DOI: 10.1016/j.micpath.2021.105265] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 04/27/2021] [Accepted: 10/21/2021] [Indexed: 12/26/2022]
Abstract
Campylobacter jejuni is a highly frequent cause of gastrointestinal foodborne disease in humans throughout the world. Disease outcomes vary from mild to severe diarrhea, and in rare cases the Guillain-Barré syndrome or reactive arthritis can develop as a post-infection complication. Transmission to humans usually occurs via the consumption of a range of foods, especially those associated with the consumption of raw or undercooked poultry meat, unpasteurized milk, and water-based environmental sources. When associated to food or water ingestion, the C. jejuni enters the human host intestine via the oral route and colonizes the distal ileum and colon. When it adheres and colonizes the intestinal cell surfaces, the C. jejuni is expected to express several putative virulence factors, which cause damage to the intestine either directly, by cell invasion and/or production of toxin(s), or indirectly, by triggering inflammatory responses. This review article highlights various C. jejuni characteristics - such as motility and chemotaxis - that contribute to the biological fitness of the pathogen, as well as factors involved in human host cell adhesion and invasion, and their potential role in the development of the disease. We have analyzed and critically discussed nearly 180 scientific articles covering the latest improvements in the field.
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Affiliation(s)
- Graciela Volz Lopes
- Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas (UFPel), Caixa Postal 354, 96160-000, Pelotas, RS, Brazil
| | - Tassiana Ramires
- Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas (UFPel), Caixa Postal 354, 96160-000, Pelotas, RS, Brazil
| | - Natalie Rauber Kleinubing
- Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas (UFPel), Caixa Postal 354, 96160-000, Pelotas, RS, Brazil
| | - Letícia Klein Scheik
- Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas (UFPel), Caixa Postal 354, 96160-000, Pelotas, RS, Brazil
| | - Ângela Maria Fiorentini
- Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas (UFPel), Caixa Postal 354, 96160-000, Pelotas, RS, Brazil
| | - Wladimir Padilha da Silva
- Departamento de Ciência e Tecnologia Agroindustrial, Faculdade de Agronomia Eliseu Maciel, Universidade Federal de Pelotas (UFPel), Caixa Postal 354, 96160-000, Pelotas, RS, Brazil.
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Bryant OJ, Chung BYW, Fraser GM. Chaperone-mediated coupling of subunit availability to activation of flagellar Type III secretion. Mol Microbiol 2021; 116:538-549. [PMID: 33893668 DOI: 10.1111/mmi.14731] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 04/19/2021] [Indexed: 01/07/2023]
Abstract
Bacterial flagellar subunits are exported across the cell membrane by the flagellar Type III Secretion System (fT3SS), powered by the proton motive force (pmf) and a specialized ATPase that enables the flagellar export gate to utilize the pmf electric potential (ΔΨ). Export gate activation is mediated by the ATPase stalk, FliJ, but how this process is regulated to prevent wasteful dissipation of pmf in the absence of subunit cargo is not known. Here, we show that FliJ activation of the export gate is regulated by flagellar export chaperones. FliJ binds unladen chaperones and, by using novel chaperone variants specifically defective for FliJ binding, we show that disruption of this interaction attenuates motility and cognate subunit export. We demonstrate in vitro that chaperones and the FlhA export gate component compete for binding to FliJ, and show in vivo that unladen chaperones, which would be present in the cell when subunit levels are low, sequester FliJ to prevent activation of the export gate and attenuate subunit export. Our data indicate a mechanism whereby chaperones couple availability of subunit cargo to pmf-driven export by the fT3SS.
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Affiliation(s)
- Owain J Bryant
- Department of Pathology, University of Cambridge, Cambridge, UK
| | - Betty Y-W Chung
- Department of Pathology, University of Cambridge, Cambridge, UK
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14
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Molecular and Physiological Adaptations to Low Temperature in Thioalkalivibrio Strains Isolated from Soda Lakes with Different Temperature Regimes. mSystems 2021; 6:6/2/e01202-20. [PMID: 33906913 PMCID: PMC8092127 DOI: 10.1128/msystems.01202-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The genus Thioalkalivibrio comprises sulfur-oxidizing bacteria thriving in soda lakes at high pH and salinity. Depending on the geographical location and the season, these lakes can strongly vary in temperature. To obtain a comprehensive understanding of the molecular and physiological adaptations to low temperature, we compared the responses of two Thioalkalivibrio strains to low (10°C) and high (30°C) temperatures. For this, the strains were grown under controlled conditions in chemostats and analyzed for their gene expression (RNA sequencing [RNA-Seq]), membrane lipid composition, and glycine betaine content. The strain Thioalkalivibrio versutus AL2T originated from a soda lake in southeast Siberia that is exposed to strong seasonal temperature differences, including freezing winters, whereas Thioalkalivibrio nitratis ALJ2 was isolated from an East African Rift Valley soda lake with a constant warm temperature the year round. The strain AL2T grew faster than ALJ2 at 10°C, likely due to its 3-fold-higher concentration of the osmolyte glycine betaine. Moreover, significant changes in the membrane lipid composition were observed for both strains, leading to an increase in their unsaturated fatty acid content via the Fab pathway to avoid membrane stiffness. Genes for the transcriptional and translational machinery, as well as for counteracting cold-induced hampering of nucleotides and proteins, were upregulated. Oxidative stress was reduced by induction of vitamin B12 biosynthesis genes, and growth at 10°C provoked downregulation of genes involved in the second half of the sulfur oxidation pathway. Genes for intracellular signal transduction were differentially expressed, and interestingly, AL2T upregulated flagellin expression, whereas ALJ2 downregulated it. IMPORTANCE In addition to their haloalkaline conditions, soda lakes can also harbor a variety of other extreme parameters, to which their microbial communities need to adapt. However, for most of these supplementary stressors, it is not well known yet how haloalkaliphiles adapt and resist. Here, we studied the strategy for adaptation to low temperature in the haloalkaliphilic genus Thioalkalivibrio by using two strains isolated from soda lakes with different temperature regimes. Even though the strains showed a strong difference in growth rate at 10°C, they exhibited similar molecular and physiological adaptation responses. We hypothesize that they take advantage of resistance mechanisms against other stressors commonly found in soda lakes, which are therefore maintained in the bacteria living in the absence of low-temperature pressure. A major difference, however, was detected for their glycine betaine content at 10°C, highlighting the power of this osmolyte to also act as a key compound in cryoprotection. Author Video: An author video summary of this article is available.
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15
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Wadhwa N, Tu Y, Berg HC. Mechanosensitive remodeling of the bacterial flagellar motor is independent of direction of rotation. Proc Natl Acad Sci U S A 2021; 118:e2024608118. [PMID: 33876769 PMCID: PMC8054018 DOI: 10.1073/pnas.2024608118] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Motility is important for the survival and dispersal of many bacteria, and it often plays a role during infections. Regulation of bacterial motility by chemical stimuli is well studied, but recent work has added a new dimension to the problem of motility control. The bidirectional flagellar motor of the bacterium Escherichia coli recruits or releases torque-generating units (stator units) in response to changes in load. Here, we show that this mechanosensitive remodeling of the flagellar motor is independent of direction of rotation. Remodeling rate constants in clockwise rotating motors and in counterclockwise rotating motors, measured previously, fall on the same curve if plotted against torque. Increased torque decreases the off rate of stator units from the motor, thereby increasing the number of active stator units at steady state. A simple mathematical model based on observed dynamics provides quantitative insight into the underlying molecular interactions. The torque-dependent remodeling mechanism represents a robust strategy to quickly regulate output (torque) in response to changes in demand (load).
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Affiliation(s)
- Navish Wadhwa
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138;
- Rowland Institute at Harvard, Harvard University, Cambridge, MA 02142
| | - Yuhai Tu
- T. J. Watson Research Center, IBM, Yorktown Heights, NY 10598
| | - Howard C Berg
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138
- Rowland Institute at Harvard, Harvard University, Cambridge, MA 02142
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16
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Bouteiller M, Dupont C, Bourigault Y, Latour X, Barbey C, Konto-Ghiorghi Y, Merieau A. Pseudomonas Flagella: Generalities and Specificities. Int J Mol Sci 2021; 22:ijms22073337. [PMID: 33805191 PMCID: PMC8036289 DOI: 10.3390/ijms22073337] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/22/2021] [Accepted: 03/22/2021] [Indexed: 12/21/2022] Open
Abstract
Flagella-driven motility is an important trait for bacterial colonization and virulence. Flagella rotate and propel bacteria in liquid or semi-liquid media to ensure such bacterial fitness. Bacterial flagella are composed of three parts: a membrane complex, a flexible-hook, and a flagellin filament. The most widely studied models in terms of the flagellar apparatus are E. coli and Salmonella. However, there are many differences between these enteric bacteria and the bacteria of the Pseudomonas genus. Enteric bacteria possess peritrichous flagella, in contrast to Pseudomonads, which possess polar flagella. In addition, flagellar gene expression in Pseudomonas is under a four-tiered regulatory circuit, whereas enteric bacteria express flagellar genes in a three-step manner. Here, we use knowledge of E. coli and Salmonella flagella to describe the general properties of flagella and then focus on the specificities of Pseudomonas flagella. After a description of flagellar structure, which is highly conserved among Gram-negative bacteria, we focus on the steps of flagellar assembly that differ between enteric and polar-flagellated bacteria. In addition, we summarize generalities concerning the fuel used for the production and rotation of the flagellar macromolecular complex. The last part summarizes known regulatory pathways and potential links with the type-six secretion system (T6SS).
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Affiliation(s)
- Mathilde Bouteiller
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Charly Dupont
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Yvann Bourigault
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Xavier Latour
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Corinne Barbey
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Yoan Konto-Ghiorghi
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
| | - Annabelle Merieau
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (C.D.); (Y.B.); (X.L.); (C.B.); (Y.K.-G.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, 76821 Mont-Saint-Aignan, France
- Correspondence:
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17
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An organelle-tethering mechanism couples flagellation to cell division in bacteria. Dev Cell 2021; 56:657-670.e4. [PMID: 33600766 DOI: 10.1016/j.devcel.2021.01.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 12/09/2020] [Accepted: 01/20/2021] [Indexed: 11/21/2022]
Abstract
In some free-living and pathogenic bacteria, problems in the synthesis and assembly of early flagellar components can cause cell-division defects. However, the mechanism that couples cell division with the flagellar biogenesis has remained elusive. Herein, we discover the regulator MadA that controls transcription of flagellar and cell-division genes in Caulobacter crescentus. We demonstrate that MadA, a small soluble protein, binds the type III export component FlhA to promote activation of FliX, which in turn is required to license the conserved σ54-dependent transcriptional activator FlbD. While in the absence of MadA, FliX and FlbD activation is crippled, bypass mutations in FlhA restore flagellar biogenesis and cell division. Furthermore, we demonstrate that MadA safeguards the divisome stoichiometry to license cell division. We propose that MadA has a sentinel-type function that senses an early flagellar biogenesis event and, through cell-division control, ensures that a flagellated offspring emerges.
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18
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Bacterial Flagellum versus Carbon Nanotube: A Review Article on the Potential of Bacterial Flagellum as a Sustainable and Green Substance for the Synthesis of Nanotubes. SUSTAINABILITY 2020. [DOI: 10.3390/su13010021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Bacterial flagella are complex multicomponent structures that help in cell locomotion. It is composed of three major structural components: the hook, the filament and basal body. The special mechanical properties of flagellar components make them useful for the applications in nanotechnology especially in nanotube formation. Carbon nanotubes (CNTs) are nanometer scale tube-shaped material and it is very useful in many applications. However, the production of CNTs is costly and detrimental to the environment as it pollutes the environment. Therefore, bacterial flagella have become a highly interesting research area especially in producing bacterial nanotubes that could replace CNTs. In this review article, we will discuss about bacterial flagellum and carbon nanotubes in the context of their types and applications. Then, we will focus and review on the characteristics of bacterial flagellum in comparison to carbon nanotubes and subsequently, the advantages of bacterial flagellum as nanotubes in comparison with carbon nanotubes.
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19
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Attieh Z, Mouawad C, Rejasse A, Jehanno I, Perchat S, Hegna IK, Økstad OA, Kallassy Awad M, Sanchis-Borja V, El Chamy L. The fliK Gene Is Required for the Resistance of Bacillus thuringiensis to Antimicrobial Peptides and Virulence in Drosophila melanogaster. Front Microbiol 2020; 11:611220. [PMID: 33391240 PMCID: PMC7775485 DOI: 10.3389/fmicb.2020.611220] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 11/18/2020] [Indexed: 11/13/2022] Open
Abstract
Antimicrobial peptides (AMPs) are essential effectors of the host innate immune system and they represent promising molecules for the treatment of multidrug resistant microbes. A better understanding of microbial resistance to these defense peptides is thus prerequisite for the control of infectious diseases. Here, using a random mutagenesis approach, we identify the fliK gene, encoding an internal molecular ruler that controls flagella hook length, as an essential element for Bacillus thuringiensis resistance to AMPs in Drosophila. Unlike its parental strain, that is highly virulent to both wild-type and AMPs deficient mutant flies, the fliK deletion mutant is only lethal to the latter's. In agreement with its conserved function, the fliK mutant is non-flagellated and exhibits highly compromised motility. However, comparative analysis of the fliK mutant phenotype to that of a fla mutant, in which the genes encoding flagella proteins are interrupted, indicate that B. thuringiensis FliK-dependent resistance to AMPs is independent of flagella assembly. As a whole, our results identify FliK as an essential determinant for B. thuringiensis virulence in Drosophila and provide new insights on the mechanisms underlying bacteria resistance to AMPs.
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Affiliation(s)
- Zaynoun Attieh
- UR-EGP, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Carine Mouawad
- UR-EGP, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
| | - Agnès Rejasse
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Isabelle Jehanno
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Stéphane Perchat
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Ida K. Hegna
- Department of Pharmacy, Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | - Ole A. Økstad
- Department of Pharmacy, Centre for Integrative Microbial Evolution (CIME), Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
| | | | - Vincent Sanchis-Borja
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Laure El Chamy
- UR-EGP, Faculté des Sciences, Université Saint-Joseph de Beyrouth, Beirut, Lebanon
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20
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Cambré A, Aertsen A. Bacterial Vivisection: How Fluorescence-Based Imaging Techniques Shed a Light on the Inner Workings of Bacteria. Microbiol Mol Biol Rev 2020; 84:e00008-20. [PMID: 33115939 PMCID: PMC7599038 DOI: 10.1128/mmbr.00008-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The rise in fluorescence-based imaging techniques over the past 3 decades has improved the ability of researchers to scrutinize live cell biology at increased spatial and temporal resolution. In microbiology, these real-time vivisections structurally changed the view on the bacterial cell away from the "watery bag of enzymes" paradigm toward the perspective that these organisms are as complex as their eukaryotic counterparts. Capitalizing on the enormous potential of (time-lapse) fluorescence microscopy and the ever-extending pallet of corresponding probes, initial breakthroughs were made in unraveling the localization of proteins and monitoring real-time gene expression. However, later it became clear that the potential of this technique extends much further, paving the way for a focus-shift from observing single events within bacterial cells or populations to obtaining a more global picture at the intra- and intercellular level. In this review, we outline the current state of the art in fluorescence-based vivisection of bacteria and provide an overview of important case studies to exemplify how to use or combine different strategies to gain detailed information on the cell's physiology. The manuscript therefore consists of two separate (but interconnected) parts that can be read and consulted individually. The first part focuses on the fluorescent probe pallet and provides a perspective on modern methodologies for microscopy using these tools. The second section of the review takes the reader on a tour through the bacterial cell from cytoplasm to outer shell, describing strategies and methods to highlight architectural features and overall dynamics within cells.
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Affiliation(s)
- Alexander Cambré
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
| | - Abram Aertsen
- KU Leuven, Department of Microbial and Molecular Systems, Faculty of Bioscience Engineering, Leuven, Belgium
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21
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Santiveri M, Roa-Eguiara A, Kühne C, Wadhwa N, Hu H, Berg HC, Erhardt M, Taylor NM. Structure and Function of Stator Units of the Bacterial Flagellar Motor. Cell 2020; 183:244-257.e16. [DOI: 10.1016/j.cell.2020.08.016] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/09/2020] [Accepted: 08/11/2020] [Indexed: 12/17/2022]
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22
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Sidhu-Muñoz RS, Tejedor C, Vizcaíno N. The Three Flagellar Loci of Brucella ovis PA Are Dispensable for Virulence in Cellular Models and Mice. Front Vet Sci 2020; 7:441. [PMID: 32851024 PMCID: PMC7410920 DOI: 10.3389/fvets.2020.00441] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 06/18/2020] [Indexed: 12/22/2022] Open
Abstract
Brucella ovis is a facultative intracellular bacterium that causes a non-zoonotic ovine brucellosis mainly characterized by male genital lesions and is responsible for important economic losses in sheep farming areas. Studies about the virulence mechanisms of Brucella have been mostly performed with smooth (bearing O-polysaccharide in lipopolysaccharide) zoonotic species, and those performed with B. ovis have revealed similarities but also relevant differences. Except for few strains recently isolated from unconventional hosts, Brucella species are non-motile but contain the genes required to assemble a flagellum, which are organized in three main loci of about 18.5, 6.4, and 7.8 kb. Although these loci contain different pseudogenes depending on the non-motile Brucella species, smooth B. melitensis 16M builds a sheathed flagellum under particular culture conditions and requires flagellar genes for virulence. However, nothing is known in this respect regarding other Brucella strains. In this work, we have constructed a panel of B. ovis PA mutants defective in one, two or the three flagellar loci in order to assess their role in virulence of this rough (lacking O-polysaccharide) Brucella species. No relevant differences in growth, outer membrane-related properties or intracellular behavior in cellular models were observed between flagellar mutants and the parental strain, which is in accordance with previous results with B. melitensis 16M single-gene mutants. However, contrary to these B. melitensis mutants, unable to establish a chronic infection in mice, removal of the three flagellar loci in B. ovis did not affect virulence in the mouse model. These results evidence new relevant differences between B. ovis and B. melitensis, two species highly homologous at the DNA level and that cause ovine brucellosis, but that exhibit differences in the zoonotic potential, pathogenicity and tissue tropism.
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Affiliation(s)
- Rebeca S Sidhu-Muñoz
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
| | - Carmen Tejedor
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Nieves Vizcaíno
- Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain.,Instituto de Investigación Biomédica de Salamanca (IBSAL), Salamanca, Spain
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23
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Bouteiller M, Gallique M, Bourigault Y, Kosta A, Hardouin J, Massier S, Konto-Ghiorghi Y, Barbey C, Latour X, Chane A, Feuilloley M, Merieau A. Crosstalk between the Type VI Secretion System and the Expression of Class IV Flagellar Genes in the Pseudomonas fluorescens MFE01 Strain. Microorganisms 2020; 8:microorganisms8050622. [PMID: 32344878 PMCID: PMC7286023 DOI: 10.3390/microorganisms8050622] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/16/2020] [Accepted: 04/23/2020] [Indexed: 11/16/2022] Open
Abstract
Type VI secretion systems (T6SSs) are contractile bacterial multiprotein nanomachines that enable the injection of toxic effectors into prey cells. The Pseudomonas fluorescens MFE01 strain has T6SS antibacterial activity and can immobilise competitive bacteria through the T6SS. Hcp1 (hemolysin co-regulated protein 1), a constituent of the T6SS inner tube, is involved in such prey cell inhibition of motility. Paradoxically, disruption of the hcp1 or T6SS contractile tail tssC genes results in the loss of the mucoid and motile phenotypes in MFE01. Here, we focused on the relationship between T6SS and flagella-associated motility. Electron microscopy revealed the absence of flagellar filaments for MFE01Δhcp1 and MFE01ΔtssC mutants. Transcriptomic analysis showed a reduction in the transcription of class IV flagellar genes in these T6SS mutants. However, transcription of fliA, the gene encoding the class IV flagellar sigma factor, was unaffected. Over-expression of fliA restored the motile and mucoid phenotypes in both MFE01Δhcp1+fliA, and MFE01ΔtssC+fliA and a fliA mutant displayed the same phenotypes as MFE01Δhcp1 and MFE01ΔtssC. Moreover, the FliA anti-sigma factor FlgM was not secreted in the T6SS mutants, and flgM over-expression reduced both motility and mucoidy. This study provides arguments to unravel the crosstalk between T6SS and motility.
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Affiliation(s)
- Mathilde Bouteiller
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Mathias Gallique
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- Meakins-Christie laboratories, Research Institute of the McGill University Health Centre, Montreal, QC H4A 3J1, Canada
- Department of Chemical Engineering, McGill University, Montreal, QC H3A 0C5, Canada
| | - Yvann Bourigault
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Artemis Kosta
- Plateforme de Microscopie de l’Institut de Microbiologie de la Méditerranée, IMM, Institut de Microbiologie, FR3479, Campus CNRS, 13402 Marseille cedex 20, France;
| | - Julie Hardouin
- Polymers, Biopolymers, Surface Laboratory, UMR 6270 CNRS, University of Rouen, F-76821 Mont-Saint-Aignan cedex, France; (J.H.); (S.M.)
- PISSARO Proteomics Facility, Université de Rouen, F-76821 Mont-Saint-Aignan, France
| | - Sebastien Massier
- Polymers, Biopolymers, Surface Laboratory, UMR 6270 CNRS, University of Rouen, F-76821 Mont-Saint-Aignan cedex, France; (J.H.); (S.M.)
- PISSARO Proteomics Facility, Université de Rouen, F-76821 Mont-Saint-Aignan, France
| | - Yoan Konto-Ghiorghi
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
| | - Corinne Barbey
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Xavier Latour
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Andréa Chane
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
| | - Marc Feuilloley
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
| | - Annabelle Merieau
- LMSM, Laboratoire de Microbiologie Signaux et Microenvironnement, EA 4312, Normandy University, Université de Rouen, 27000 Evreux, France; (M.B.); (M.G.); (Y.B.); (Y.K.-G.); (C.B.); (X.L.); (A.C.); (M.F.)
- SFR NORVEGE, Structure Fédérative de Recherche Normandie Végétale, FED 4277, F-76821 Mont-Saint-Aignan, France
- Correspondence:
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Abstract
Bacterial and archaeal flagellins are remarkable in having a shared region with variation in housekeeping proteins and a region with extreme diversity, perhaps greater than for any other protein. Analysis of the 113,285 available full-gene sequences of flagellin genes from published bacterial and archaeal sequences revealed the nature and enormous extent of flagellin diversity. There were 35,898 unique amino acid sequences that were resolved into 187 clusters. Analysis of the Escherichia coli and Salmonella enterica flagellins revealed that the variation occurs at two levels. The first is the division of the variable regions into sequence forms that are so divergent that there is no meaningful alignment even within species, and these corresponded to the E. coli or S. enterica H-antigen groups. The second level is variation within these groups, which is extensive in both species. Shared sequence would allow PCR of the variable regions and thus strain-level analysis of microbiome DNA. Flagellin, the agent of prokaryotic flagellar motion, is very widely distributed and is the H antigen of serology. Flagellin molecules have a variable region that confers serotype specificity, encoded by the middle of the gene, and also conserved regions encoded by the two ends of the gene. We collected all available prokaryotic flagellin protein sequences and found the variable region diversity to be at two levels. In each species investigated, there are hypervariable region (HVR) forms without detectable homology in protein sequences between them. There is also considerable variation within HVR forms, indicating that some have been diverging for thousands of years and that interphylum horizontal gene transfers make a major contribution to the evolution of such atypical diversity. IMPORTANCE Bacterial and archaeal flagellins are remarkable in having a shared region with variation in housekeeping proteins and a region with extreme diversity, perhaps greater than for any other protein. Analysis of the 113,285 available full-gene sequences of flagellin genes from published bacterial and archaeal sequences revealed the nature and enormous extent of flagellin diversity. There were 35,898 unique amino acid sequences that were resolved into 187 clusters. Analysis of the Escherichia coli and Salmonella enterica flagellins revealed that the variation occurs at two levels. The first is the division of the variable regions into sequence forms that are so divergent that there is no meaningful alignment even within species, and these corresponded to the E. coli or S. enterica H-antigen groups. The second level is variation within these groups, which is extensive in both species. Shared sequence would allow PCR of the variable regions and thus strain-level analysis of microbiome DNA.
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25
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Kim JM, Garcia-Alcala M, Balleza E, Cluzel P. Stochastic transcriptional pulses orchestrate flagellar biosynthesis in Escherichia coli. SCIENCE ADVANCES 2020; 6:eaax0947. [PMID: 32076637 PMCID: PMC7002133 DOI: 10.1126/sciadv.aax0947] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 11/22/2019] [Indexed: 05/28/2023]
Abstract
The classic picture of flagellum biosynthesis in Escherichia coli, inferred from population measurements, depicts a deterministic program where promoters are sequentially up-regulated and are maintained steadily active throughout exponential growth. However, complex regulatory dynamics at the single-cell level can be masked by bulk measurements. Here, we discover that in individual E. coli cells, flagellar promoters are stochastically activated in pulses. These pulses are coordinated within specific classes of promoters and comprise "on" and "off" states, each of which can span multiple generations. We demonstrate that in this pulsing program, the regulatory logic of flagellar assembly dictates which promoters skip pulses. Surprisingly, pulses do not require specific transcriptional or translational regulation of the flagellar master regulator, FlhDC, but instead appears to be essentially governed by an autonomous posttranslational circuit. Our results suggest that even topologically simple transcriptional networks can generate unexpectedly rich temporal dynamics and phenotypic heterogeneities.
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Affiliation(s)
- J. Mark Kim
- Department of Molecular and Cellular Biology, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Mayra Garcia-Alcala
- Department of Molecular and Cellular Biology, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
| | - Enrique Balleza
- Department of Molecular and Cellular Biology, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
| | - Philippe Cluzel
- Department of Molecular and Cellular Biology, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138, USA
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26
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Andrade MO, Pang Z, Achor DS, Wang H, Yao T, Singer BH, Wang N. The flagella of 'Candidatus Liberibacter asiaticus' and its movement in planta. MOLECULAR PLANT PATHOLOGY 2020; 21:109-123. [PMID: 31721403 PMCID: PMC6913195 DOI: 10.1111/mpp.12884] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Citrus huanglongbing (HLB) is the most devastating citrus disease worldwide. 'Candidatus Liberibacter asiaticus' (Las) is the most prevalent HLB causal agent that is yet to be cultured. Here, we analysed the flagellar genes of Las and Rhizobiaceae and observed two characteristics unique to the flagellar proteins of Las: (i) a shorter primary structure of the rod capping protein FlgJ than other Rhizobiaceae bacteria and (ii) Las contains only one flagellin-encoding gene flaA (CLIBASIA_02090), whereas other Rhizobiaceae species carry at least three flagellin-encoding genes. Only flgJAtu but not flgJLas restored the swimming motility of Agrobacterium tumefaciens flgJ mutant. Pull-down assays demonstrated that FlgJLas interacts with FlgB but not with FliE. Ectopic expression of flaALas in A. tumefaciens mutants restored the swimming motility of ∆flaA mutant and ∆flaAD mutant, but not that of the null mutant ∆flaABCD. No flagellum was observed for Las in citrus and dodder. The expression of flagellar genes was higher in psyllids than in planta. In addition, western blotting using flagellin-specific antibody indicates that Las expresses flagellin protein in psyllids, but not in planta. The flagellar features of Las in planta suggest that Las movement in the phloem is not mediated by flagella. We also characterized the movement of Las after psyllid transmission into young flush. Our data support a model that Las remains inside young flush after psyllid transmission and before the flush matures. The delayed movement of Las out of young flush after psyllid transmission provides opportunities for targeted treatment of young flush for HLB control.
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Affiliation(s)
- Maxuel O. Andrade
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceUniversity of Florida/Institute of Food and Agricultural SciencesLake AlfredFLUSA
| | - Zhiqian Pang
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceUniversity of Florida/Institute of Food and Agricultural SciencesLake AlfredFLUSA
| | - Diann S. Achor
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceUniversity of Florida/Institute of Food and Agricultural SciencesLake AlfredFLUSA
| | - Han Wang
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceUniversity of Florida/Institute of Food and Agricultural SciencesLake AlfredFLUSA
| | - Tingshan Yao
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceUniversity of Florida/Institute of Food and Agricultural SciencesLake AlfredFLUSA
- National Engineering Research Center for Citrus, Citrus Research Institute, Southwest UniversityChongqing400712People’s Republic of China
| | - Burton H. Singer
- Emerging Pathogens InstituteUniversity of FloridaGainesvilleFLUSA
| | - Nian Wang
- Citrus Research and Education CenterDepartment of Microbiology and Cell ScienceUniversity of Florida/Institute of Food and Agricultural SciencesLake AlfredFLUSA
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27
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Huen J, Yan Z, Iwashkiw J, Dubey S, Gimenez MC, Ortiz ME, Patel SV, Jones MD, Riazi A, Terebiznik M, Babaei S, Shahinas D. A Novel Single Domain Antibody Targeting FliC Flagellin of Salmonella enterica for Effective Inhibition of Host Cell Invasion. Front Microbiol 2019; 10:2665. [PMID: 31849856 PMCID: PMC6901939 DOI: 10.3389/fmicb.2019.02665] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 11/01/2019] [Indexed: 11/26/2022] Open
Abstract
The enteric pathogen, Salmonella enterica is a major cause of human gastroenteritis globally and with increasing bacterial resistance to antibiotics, alternative solutions are urgently needed. Single domain antibodies (sdAbs), the smallest antibody fragments that retain antigen binding specificity and affinity, are derived from variable heavy-chain only fragments (VHH) of camelid heavy-chain-only immunoglobulins. SdAbs typically contain a single disulfide bond simplifying recombinant protein production in microbial systems. These factors make sdAbs ideally suited for the development of effective anti-bacterial therapeutics. To this end, we generated an anti-Salmonella VHH library from which we screened for high affinity sdAbs. We present a novel sdAb (Abi-Se07) that targets the Salmonella virulence factor, FliC, required for bacterial motility and invasion of host cells. We demonstrate that Abi-Se07 bound FliC with a K D of 16.2 ± 0.1 nM. In addition, Abi-Se07 exhibited cross-serovar binding to whole cells of S. enterica serovar Typhimurium, Heidelberg, and Hadar. Abi-Se07 significantly inhibited bacterial motility and significantly reduced S. enterica colonization in a more native environment of chicken jejunum epithelium. Taken together, we have identified a novel anti-Salmonella sdAb and discuss future efforts toward therapeutic development.
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Affiliation(s)
- Jennifer Huen
- AbCelex Technologies Inc., Mississauga, ON, Canada
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Zhun Yan
- AbCelex Technologies Inc., Mississauga, ON, Canada
| | | | | | - Maria C. Gimenez
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Maria E. Ortiz
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
| | | | | | - Ali Riazi
- AbCelex Technologies Inc., Mississauga, ON, Canada
| | - Mauricio Terebiznik
- Department of Biological Sciences, University of Toronto at Scarborough, Toronto, ON, Canada
- Department of Cell and Systems Biology, University of Toronto at Scarborough, Toronto, ON, Canada
| | - Saeid Babaei
- AbCelex Technologies Inc., Mississauga, ON, Canada
| | - Dea Shahinas
- AbCelex Technologies Inc., Mississauga, ON, Canada
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28
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Smyrli M, Triga A, Dourala N, Varvarigos P, Pavlidis M, Quoc VH, Katharios P. Comparative Study on A Novel Pathogen of European Seabass. Diversity of Aeromonas veronii in the Aegean Sea. Microorganisms 2019; 7:microorganisms7110504. [PMID: 31671797 PMCID: PMC6921072 DOI: 10.3390/microorganisms7110504] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 10/16/2019] [Accepted: 10/25/2019] [Indexed: 01/01/2023] Open
Abstract
Aeromonas veronii is an emerging pathogen causing severe pathology and mortalities in European seabass aquaculture in the Aegean Sea, Mediterranean. More than 50 strains of the pathogen were characterized biochemically and genetically in order to study the epidemiology of the disease, as well as the phylogeny and virulence of the bacterium. Based on the phenotypic characteristics, the isolates form three groups consisting of: (a) the West Aegean Sea, non-motile, non-pigment-producing strains, (b) the West Aegean Sea, motile, and pigment-producing strains and (c) the East Aegean Sea motile strains that produce minute amounts of pigment. All strains were highly similar at the genomic level; however, the pattern of West/East geographic origin was reflected in biochemical properties, in general genomic level comparison and in the putative virulent factors studied. Type VI secretion system was not detected in the western strains. The outer membrane protein (OMP) profile which contains proteins that are putative antigenic factors, was very similar between strains from the different areas. Although most of the OMPs were detected in all strains with great sequence similarity, diversification according to geographic origin was evident in known antigenic factors such as the maltoporin LamB. A systematic comparative analysis of the strains is presented and discussed in view of the emergence of A. veronii as a significant pathogen for the Mediterranean aquaculture.
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Affiliation(s)
- Maria Smyrli
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
- Department of Biology, University of Crete, Heraklion, 70013 Crete, Greece.
| | - Adriana Triga
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
- Department of Biology, University of Crete, Heraklion, 70013 Crete, Greece.
| | - Nancy Dourala
- Fish Pathology Department, Selonda Aquaculture, 15125 Athens, Greece.
| | | | - Michael Pavlidis
- Department of Biology, University of Crete, Heraklion, 70013 Crete, Greece.
| | - Viet Ha Quoc
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
| | - Pantelis Katharios
- Institute of Marine Biology, Biotechnology and Aquaculture, Hellenic Centre for Marine Research, Heraklion, 71500 Crete, Greece.
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29
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Abstract
Cells from all three domains of life on Earth utilize motile macromolecular devices that protrude from the cell surface to generate forces that allow them to swim through fluid media. Research carried out on archaea during the past decade or so has led to the recognition that, despite their common function, the motility devices of the three domains display fundamental differences in their properties and ancestry, reflecting a striking example of convergent evolution. Thus, the flagella of bacteria and the archaella of archaea employ rotary filaments that assemble from distinct subunits that do not share a common ancestor and generate torque using energy derived from distinct fuel sources, namely chemiosmotic ion gradients and FlaI motor-catalyzed ATP hydrolysis, respectively. The cilia of eukaryotes, however, assemble via kinesin-2-driven intraflagellar transport and utilize microtubules and ATP-hydrolyzing dynein motors to beat in a variety of waveforms via a sliding filament mechanism. Here, with reference to current structural and mechanistic information about these organelles, we briefly compare the evolutionary origins, assembly and tactic motility of archaella, flagella and cilia.
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Affiliation(s)
- Shahid Khan
- Molecular Biology Consortium, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
| | - Jonathan M Scholey
- Department of Molecular and Cell Biology, University of California @ Davis, CA 95616, USA.
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30
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Cho SY, Song WS, Yoon SI. Crystal structure of the flagellar cap protein FliD from Bdellovibrio bacteriovorus. Biochem Biophys Res Commun 2019; 519:652-658. [PMID: 31542231 DOI: 10.1016/j.bbrc.2019.09.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 09/08/2019] [Indexed: 01/10/2023]
Abstract
Bdellovibrio bacteriovorus is a predator bacterial species of the Deltaproteobacteria class that requires flagellum-mediated motility to initiate the parasitization of other gram-negative bacteria. The flagellum is capped by FliD, which polymerizes flagellin into a flagellar filament. FliD has been reported to function as a species-specific oligomer, such as a tetramer, a pentamer, or a hexamer, in members of the Gammaproteobacteria class. However, the oligomeric state and structural features of FliD from bacterial species outside the Gammaproteobacteria class are unknown. Based on structural and biochemical analyses, we report here that B. bacteriovorus FliD (bbFliD) forms a tetramer. bbFliD tetramerizes in a circular head-to-tail arrangement by inserting the D2 domain of one subunit into the concave surface of the second subunit generated between the D2 and D3 domains as observed in Serratia marcescens FliD. However, bbFliD adopts a more compact and flat oligomeric structure, which exhibits a more extended tetramerization interface flanked by two additional surfaces due to different intersubunit and interdomain organizations as well as an elongated loop. In conclusion, FliD from B. bacteriovorus, which belongs to the Deltaproteobacteria class, also produces a tetramer similar to FliD from Gammaproteobacterial species but adopts a unique species-specific oligomeric structure.
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Affiliation(s)
- So Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Wan Seok Song
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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31
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Iyer D, Gulyuk AV, Reddy P, Kirste R, Collazo R, LaJeunesse DR, Ivanisevic A. Behavior of E. coli with Variable Surface Morphology Changes on Charged Semiconductor Interfaces. ACS APPLIED BIO MATERIALS 2019; 2:4044-4051. [PMID: 35021338 PMCID: PMC10167750 DOI: 10.1021/acsabm.9b00573] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Bacterial behavior is often controlled by structural and composition elements of their cell wall. Using genetic mutant strains that change specific aspects of their surface structure, we modified bacterial behavior in response to semiconductor surfaces. We monitored the adhesion, membrane potential, and catalase activity of the Gram-negative bacterium Escherichia coli (E. coli) that were mutant for genes encoding components of their surface architecture, specifically flagella, fimbriae, curli, and components of the lipopolysaccharide membrane, while on gallium nitride (GaN) surfaces with different surface potentials. The bacteria and the semiconductor surface properties were recorded prior to the biofilm studies. The data from the materials and bioassays characterization supports the notion that alteration of the surface structure of the E. coli bacterium resulted in changes to bacterium behavior on the GaN medium. Loss of specific surface structure on the E. coli bacterium reduced its sensitivity to the semiconductor interfaces, while other mutations increase bacterial adhesion when compared to the wild-type control E. coli bacteria. These results demonstrate that bacterial behavior and responses to GaN semiconductor materials can be controlled genetically and can be utilized to tune the fate of living bacteria on GaN surfaces.
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Affiliation(s)
- Divya Iyer
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina-Greensboro, Greensboro, North Carolina 27401, United States
| | - Alexey V. Gulyuk
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Pramod Reddy
- Adroit Materials, 2054 Kildaire Farm Road, Suite 205, Cary, North Carolina 27518, United States
| | - Ronny Kirste
- Adroit Materials, 2054 Kildaire Farm Road, Suite 205, Cary, North Carolina 27518, United States
| | - Ramon Collazo
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Dennis R. LaJeunesse
- Department of Nanoscience, Joint School of Nanoscience and Nanoengineering, University of North Carolina-Greensboro, Greensboro, North Carolina 27401, United States
| | - Albena Ivanisevic
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States
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32
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Koomey M. O-linked protein glycosylation in bacteria: snapshots and current perspectives. Curr Opin Struct Biol 2019; 56:198-203. [DOI: 10.1016/j.sbi.2019.03.020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/22/2019] [Accepted: 03/13/2019] [Indexed: 12/27/2022]
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33
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Cho SY, Song WS, Oh HB, Kim HU, Jung HS, Yoon SI. Structural analysis of the flagellar capping protein FliD from Helicobacter pylori. Biochem Biophys Res Commun 2019; 514:98-104. [PMID: 31023530 DOI: 10.1016/j.bbrc.2019.04.065] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 04/09/2019] [Indexed: 01/17/2023]
Abstract
Helicobacter pylori is a pathogenic flagellated bacterium that infects the gastroduodenal mucosa and causes peptic ulcers in humans. FliD caps the distal end of the flagellar filament and is essential in filament growth. Moreover, FliD has been studied to diagnose and prevent H. pylori infection. Here, we report structure-based molecular studies of H. pylori FliD (hpFliD). A crystal structure of hpFliD at 2.6 Å resolution presents a four-domain (D2-D5) structure, where the D3 domain forms a central platform surrounded by the other three domains (D2, D4, and D5). hpFliD domains D2 and D3 structurally resemble those of FliD orthologs, whereas the D4 and D5 domains are exclusive to hpFliD. Moreover, our ELISA analysis using anti-H. pylori antibodies demonstrated that the hpFliD-specific D4 and D5 domains are highly antigenic compared to the D2 and D3 domains. Collectively, our structural and serological analyses underscore the structural role of hpFliD domains and provide a molecular basis for vaccine and diagnosis development.
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Affiliation(s)
- So Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Wan Seok Song
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Han-Byeol Oh
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Han-Ul Kim
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon, 24341, Republic of Korea; Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon, 24341, Republic of Korea.
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34
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Yamazaki K, Kashimoto T, Morita M, Kado T, Matsuda K, Yamasaki M, Ueno S. Identification of in vivo Essential Genes of Vibrio vulnificus for Establishment of Wound Infection by Signature-Tagged Mutagenesis. Front Microbiol 2019; 10:123. [PMID: 30774628 PMCID: PMC6367243 DOI: 10.3389/fmicb.2019.00123] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 01/18/2019] [Indexed: 01/22/2023] Open
Abstract
Vibrio vulnificus can cause severe necrotic lesions within a short time. Recently, it has been reported that the numbers of wound infection cases in healthy hosts are increasing, for which surgical procedures are essential in many instances to eliminate the pathogen owing to its rapid proliferation. However, the mechanisms by which V. vulnificus can achieve wound infection in healthy hosts have not been elucidated. Here, we advance a systematic understanding of V. vulnificus wound infection through genome-wide identification of the relevant genes. Signature-tagged mutagenesis (STM) has been developed to identify functions required for the establishment of infection including colonization, rapid proliferation, and pathogenicity. Previously, STM had been regarded to be unsuitable for negative selection to detect the virulence genes of V. vulnificus owing to the low colonization and proliferation ability of this pathogen in the intestinal tract and systemic circulation. Alternatively, we successfully identified the virulence genes by applying STM to a murine model of wound infection. We examined a total of 5418 independent transposon insertion mutants by signature-tagged transposon mutagenesis and detected 71 clones as attenuated mutants consequent to disruption of genes by the insertion of a transposon. This is the first report demonstrating that the pathogenicity of V. vulnificus during wound infection is highly dependent on its characteristics: flagellar-based motility, siderophore-mediated iron acquisition system, capsular polysaccharide, lipopolysaccharide, and rapid chromosome partitioning. In particular, these functions during the wound infection process and are indispensable for proliferation in healthy hosts. Our results may thus allow the potential development of new strategies and reagents to control the proliferation of V. vulnificus and prevent human infections.
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Affiliation(s)
- Kohei Yamazaki
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Takashige Kashimoto
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Mio Morita
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Takehiro Kado
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Kaho Matsuda
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Moeko Yamasaki
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Shunji Ueno
- Laboratory of Veterinary Public Health, School of Veterinary Medicine, Kitasato University, Towada, Japan
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35
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Kaplan M, Ghosal D, Subramanian P, Oikonomou CM, Kjaer A, Pirbadian S, Ortega DR, Briegel A, El-Naggar MY, Jensen GJ. The presence and absence of periplasmic rings in bacterial flagellar motors correlates with stator type. eLife 2019; 8:43487. [PMID: 30648971 PMCID: PMC6375700 DOI: 10.7554/elife.43487] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/19/2018] [Indexed: 12/22/2022] Open
Abstract
The bacterial flagellar motor, a cell-envelope-embedded macromolecular machine that functions as a cellular propeller, exhibits significant structural variability between species. Different torque-generating stator modules allow motors to operate in different pH, salt or viscosity levels. How such diversity evolved is unknown. Here, we use electron cryo-tomography to determine the in situ macromolecular structures of three Gammaproteobacteria motors: Legionella pneumophila, Pseudomonas aeruginosa, and Shewanella oneidensis, providing the first views of intact motors with dual stator systems. Complementing our imaging with bioinformatics analysis, we find a correlation between the motor’s stator system and its structural elaboration. Motors with a single H+-driven stator have only the core periplasmic P- and L-rings; those with dual H+-driven stators have an elaborated P-ring; and motors with Na+ or Na+/H+-driven stators have both their P- and L-rings embellished. Our results suggest an evolution of structural elaboration that may have enabled pathogenic bacteria to colonize higher-viscosity environments in animal hosts. Bacteria are so small that for them, making their way through water is like swimming in roofing tar for us. In response, these organisms have evolved a molecular machine that helps them move in their environment. Named the bacterial flagellum, this complex assemblage of molecules is formed of three main parts: a motor that spans the inner and outer membranes of the cell, and then a ‘hook’ that connects to a long filament which extends outside the bacterium. More precisely, the motor is formed of the stator, an ion pump that stays still, and of a rotor that can spin. Different rings can also be present in the space between the inner and outer membranes (the periplasm) and surround these components. The stator uses ions to generate the energy that makes the rotor whirl. In turn, this movement sets the filament in motion, propelling the bacterium. Depending on where the bacteria live, the stator can use different types of ions. In addition, while many species have a single stator system per motor, some may have several stator systems for one motor: this may help the microorganisms move in different conditions. As microbes colonize environments with a different pH or viscosity, they constantly evolve new versions of the motor which are more suitable to their new surroundings. However, a part of the motor remains the same across species. Overall, it is still unclear how bacterial flagella evolve, but examining the structure of new motors can shed light upon this process. Here, Kaplan et al. combine a bioinformatics approach with an imaging technique known as electron cryo-tomography to dissect the structure of the flagellar motor of three species of bacteria with different stator systems, and compare these to known motors of the same class. The results reveal a correlation between the nature of the stator system and the presence of certain elements. Stators that use sodium ions, or both sodium and hydrogen ions, are associated with two periplasmic rings surrounding the conserved motor structure. These rings do not exist in motors with single hydrogen-driven stators. Motors with dual hydrogen-driven stators are, to some extent, an ‘intermediate state’, with only one of those rings present. As all the studied species currently exist, it is difficult to know which version of the motor is the most ancient, and which one has evolved more recently. Capturing the diversity of bacterial motors gives us insight into the evolutionary forces that shape complex molecular structures, which is essential to understand how life evolved on Earth. More practically, this knowledge may also help us design better nanomachines to power microscopic robots.
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Affiliation(s)
- Mohammed Kaplan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Debnath Ghosal
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Poorna Subramanian
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Catherine M Oikonomou
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Andreas Kjaer
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Sahand Pirbadian
- Department of Physics and Astronomy, Biological Sciences, and Chemistry, University of Southern California, Los Angeles, United States
| | - Davi R Ortega
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Ariane Briegel
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States
| | - Mohamed Y El-Naggar
- Department of Physics and Astronomy, Biological Sciences, and Chemistry, University of Southern California, Los Angeles, United States
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, United States.,Howard Hughes Medical Institute, California Institute of Technology, Pasadena, United States
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36
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Increased sporulation underpins adaptation of Clostridium difficile strain 630 to a biologically-relevant faecal environment, with implications for pathogenicity. Sci Rep 2018; 8:16691. [PMID: 30420658 PMCID: PMC6232153 DOI: 10.1038/s41598-018-35050-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 10/24/2018] [Indexed: 02/07/2023] Open
Abstract
Clostridium difficile virulence is driven primarily by the processes of toxinogenesis and sporulation, however many in vitro experimental systems for studying C. difficile physiology have arguably limited relevance to the human colonic environment. We therefore created a more physiologically–relevant model of the colonic milieu to study gut pathogen biology, incorporating human faecal water (FW) into growth media and assessing the physiological effects of this on C. difficile strain 630. We identified a novel set of C. difficile–derived metabolites in culture supernatants, including hexanoyl– and pentanoyl–amino acid derivatives by LC-MSn. Growth of C. difficile strain 630 in FW media resulted in increased cell length without altering growth rate and RNA sequencing identified 889 transcripts as differentially expressed (p < 0.001). Significantly, up to 300–fold increases in the expression of sporulation–associated genes were observed in FW media–grown cells, along with reductions in motility and toxin genes’ expression. Moreover, the expression of classical stress–response genes did not change, showing that C. difficile is well–adapted to this faecal milieu. Using our novel approach we have shown that interaction with FW causes fundamental changes in C. difficile biology that will lead to increased disease transmissibility.
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Crystal structure of FlgL and its implications for flagellar assembly. Sci Rep 2018; 8:14307. [PMID: 30250171 PMCID: PMC6155364 DOI: 10.1038/s41598-018-32460-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 09/07/2018] [Indexed: 01/05/2023] Open
Abstract
Bacteria move toward attractants and away from repellants by rotating their flagellum. The bacterial flagellum assembles through the ordered organization of more than 30 different proteins. Among the diverse flagellar proteins, FlgL forms the junction between the hook and the filament in the flagellum together with FlgK and provides a structural base where flagellin, a filament-forming protein, is inserted for the initiation of filament elongation. However, the functional and structural information available for FlgL is highly limited. To provide structural insights into the cross-linkage between the FlgL junction and the flagellin filament, we determined the crystal structures of FlgL from gram-positive Bacillus cereus (bcFlgL) and gram-negative Xanthomonas campestris (xcFlgL). bcFlgL contains one domain (D1), whereas xcFlgL adopts a two-domain structure that consists of the D1 and D2 domains. The constant D1 domain of FlgL adopts a rod structure that is generated by four longitudinal segments. This four-segment structure is recapitulated in filament and junction proteins but not in hook and rod proteins, allowing us to propose a junction-filament assembly mechanism based on a quasi-homotypic interaction. The D2 domain of xcFlgL resembles that of another junction protein, FlgK, suggesting the structural and functional relatedness of FlgL and FlgK.
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38
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Bastos-Arrieta J, Revilla-Guarinos A, Uspal WE, Simmchen J. Bacterial Biohybrid Microswimmers. Front Robot AI 2018; 5:97. [PMID: 33500976 PMCID: PMC7805739 DOI: 10.3389/frobt.2018.00097] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 07/30/2018] [Indexed: 12/12/2022] Open
Abstract
Over millions of years, Nature has optimized the motion of biological systems at the micro and nanoscales. Motor proteins to motile single cells have managed to overcome Brownian motion and solve several challenges that arise at low Reynolds numbers. In this review, we will briefly describe naturally motile systems and their strategies to move, starting with a general introduction that surveys a broad range of developments, followed by an overview about the physical laws and parameters that govern and limit motion at the microscale. We characterize some of the classes of biological microswimmers that have arisen in the course of evolution, as well as the hybrid structures that have been constructed based on these, ranging from Montemagno's ATPase motor to the SpermBot. Thereafter, we maintain our focus on bacteria and their biohybrids. We introduce the inherent properties of bacteria as a natural microswimmer and explain the different principles bacteria use for their motion. We then elucidate different strategies that have been employed for the coupling of a variety of artificial microobjects to the bacterial surface, and evaluate the different effects the coupled objects have on the motion of the "biohybrid." Concluding, we give a short overview and a realistic evaluation of proposed applications in the field.
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Affiliation(s)
| | - Ainhoa Revilla-Guarinos
- Department of General Microbiology, Institute of Microbiology, Technische Universität Dresden, Dresden, Germany
| | - William E Uspal
- Department of Theory of Inhomogeneous Condensed Matter, Max-Planck-Institut für Intelligente Systeme, Stuttgart, Germany.,IV. Institut für Theoretische Physik, Universität Stuttgart, Stuttgart, Germany
| | - Juliane Simmchen
- Physikalische Chemie, Technische Universität Dresden, Dresden, Germany
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39
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Kovács N, Jankovics H, Vonderviszt F. Deletion analysis of the flagellum-specific secretion signal in Salmonella flagellin. FEBS Lett 2018; 592:3074-3081. [PMID: 30043975 DOI: 10.1002/1873-3468.13200] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 06/30/2018] [Accepted: 07/13/2018] [Indexed: 11/10/2022]
Abstract
The export signal recognized by the flagellum-specific export machinery is harbored within the highly conserved 26-47 segment of the disordered N-terminal part of Salmonella flagellin. In this work, we aimed to further localize the essential part of the export signal by deletion analysis and investigated how the length of the spacer segment preceding the signal affects export efficiency. Export signal variants were attached to a reporter protein, the CCP2 domain of human C1r protein, and export efficiency of the fusion constructs was studied. Our results suggest that almost any continuous oligopeptide of 8-10 residues within the 26-47 segment can efficiently direct flagellar export if preceded by a spacer segment of at least 15 amino acids without any specific sequential requirement.
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Affiliation(s)
- Noémi Kovács
- Bio-Nanosystems Laboratory, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém, Hungary
| | - Hajnalka Jankovics
- Bio-Nanosystems Laboratory, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém, Hungary
| | - Ferenc Vonderviszt
- Bio-Nanosystems Laboratory, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprém, Hungary
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40
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Dongre M, Singh B, Aung KM, Larsson P, Miftakhova R, Persson K, Askarian F, Johannessen M, von Hofsten J, Persson JL, Erhardt M, Tuck S, Uhlin BE, Wai SN. Flagella-mediated secretion of a novel Vibrio cholerae cytotoxin affecting both vertebrate and invertebrate hosts. Commun Biol 2018; 1:59. [PMID: 30271941 PMCID: PMC6123715 DOI: 10.1038/s42003-018-0065-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 05/09/2018] [Indexed: 02/07/2023] Open
Abstract
Using Caenorhabditis elegans as an infection host model for Vibrio cholerae predator interactions, we discovered a bacterial cytotoxin, MakA, whose function as a virulence factor relies on secretion via the flagellum channel in a proton motive force-dependent manner. The MakA protein is expressed from the polycistronic makDCBA (motility-associated killing factor) operon. Bacteria expressing makDCBA induced dramatic changes in intestinal morphology leading to a defecation defect, starvation and death in C. elegans. The Mak proteins also promoted V. cholerae colonization of the zebrafish gut causing lethal infection. A structural model of purified MakA at 1.9 Å resolution indicated similarities to members of a superfamily of bacterial toxins with unknown biological roles. Our findings reveal an unrecognized role for V. cholerae flagella in cytotoxin export that may contribute both to environmental spread of the bacteria by promoting survival and proliferation in encounters with predators, and to pathophysiological effects during infections.
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Affiliation(s)
- Mitesh Dongre
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Bhupender Singh
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Kyaw Min Aung
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Per Larsson
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Regina Miftakhova
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Karina Persson
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Fatemeh Askarian
- Faculty of Health Sciences, Department of Medical Biology, Research group of Host-Microbe Interactions, UiT-The Artic University of Norway, 9037, Tromsø, Norway
| | - Mona Johannessen
- Faculty of Health Sciences, Department of Medical Biology, Research group of Host-Microbe Interactions, UiT-The Artic University of Norway, 9037, Tromsø, Norway
| | - Jonas von Hofsten
- Umeå Centre for Molecular Medicine (UCMM), Umeå University, SE-90187, Umeå, Sweden.,Department of Integrative Medical Biology (IMB), Umeå University, SE-90187, Umeå, Sweden
| | - Jenny L Persson
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Marc Erhardt
- Helmholtz Centre for Infection Research (HZI), Inhoffenstraße 7, 38124, Braunschweig, Germany
| | - Simon Tuck
- Umeå Centre for Molecular Medicine (UCMM), Umeå University, SE-90187, Umeå, Sweden
| | - Bernt Eric Uhlin
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden
| | - Sun Nyunt Wai
- Department of Molecular Biology and The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-90187, Umeå, Sweden.
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41
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Cogo C, Pérez-Giménez J, Rajeswari CB, Luna MF, Lodeiro AR. Induction by Bradyrhizobium diazoefficiens of Different Pathways for Growth in D-mannitol or L-arabinose Leading to Pronounced Differences in CO 2 Fixation, O 2 Consumption, and Lateral-Flagellum Production. Front Microbiol 2018; 9:1189. [PMID: 29922265 PMCID: PMC5996035 DOI: 10.3389/fmicb.2018.01189] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Accepted: 05/16/2018] [Indexed: 11/20/2022] Open
Abstract
Bradyrhizobium diazoefficiens, a soybean N2-fixing symbiont, constitutes the basic input in one of the most prominent inoculant industries worldwide. This bacterium may be cultured with D-mannitol or L-arabinose as carbon-plus-energy source (C-source) with similar specific growth rates, but with higher biomass production with D-mannitol. To better understand the bacterium’s carbon metabolism, we analyzed, by liquid chromatography and tandem mass spectrometry (MS), the whole set of proteins obtained from cells grown on each C-source. Among 3,334 proteins identified, 266 were overproduced in D-mannitol and 237 in L-arabinose, but among these, only 22% from D-mannitol cultures and 35% from L-arabinose cultures were annotated with well defined functions. In the D-mannitol-differential pool we found 19 enzymes of the pentose-phosphate and Calvin–Benson–Bassham pathways and accordingly observed increased extracellular-polysaccharide production by D-mannitol grown bacteria in a CO2-enriched atmosphere. Moreover, poly-3-hydroxybutyrate biosynthesis was increased, suggesting a surplus of reducing power. In contrast, the L-arabinose-differential pool contained 11 enzymes of the L-2-keto-3-deoxyarabonate pathway, 4 enzymes for the synthesis of nicotinamide-adenine dinucleotide from aspartate, with those cultures having a threefold higher O2-consumption rate than the D-mannitol cultures. The stoichiometric balances deduced from the modeled pathways, however, resulted in similar O2 consumptions and ATP productions per C-mole of substrate. These results suggested higher maintenance-energy demands in L-arabinose, which energy may be used partly for flagella-driven motility. Since B. diazoefficiens produces the lateral-flagella system in only L-arabinose, we calculated the O2-consumption rates of a lafR::Km mutant devoid of lateral flagella cultured in L-arabinose or D-mannitol. Contrary to that of the wild-type, the O2-consumption rate of this mutant was similar on both C-sources, and accordingly outcompeted the wild-type in coculture, suggesting that the lateral flagella behaved as parasitic structures under these conditions. Proteomic data are available via ProteomeXchange with identifier PXD008263.
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Affiliation(s)
- Carolina Cogo
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas-UNLP y CCT La Plata-CONICET, La Plata, Argentina.,Departamento de Ciencias Básicas, Facultad de Ingeniería-UNLP, La Plata, Argentina
| | - Julieta Pérez-Giménez
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas-UNLP y CCT La Plata-CONICET, La Plata, Argentina
| | - Chandrasekar B Rajeswari
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas-UNLP y CCT La Plata-CONICET, La Plata, Argentina
| | - María F Luna
- Centro de Investigación y Desarrollo en Fermentaciones Industriales, Facultad de Ciencias Exactas-UNLP y CCT La Plata-CONICET, Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Argentina
| | - Aníbal R Lodeiro
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas-UNLP y CCT La Plata-CONICET, La Plata, Argentina
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42
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Xing Q, Shi K, Portaliou A, Rossi P, Economou A, Kalodimos CG. Structures of chaperone-substrate complexes docked onto the export gate in a type III secretion system. Nat Commun 2018; 9:1773. [PMID: 29720631 PMCID: PMC5932034 DOI: 10.1038/s41467-018-04137-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/05/2018] [Indexed: 12/31/2022] Open
Abstract
The flagellum and the injectisome enable bacterial locomotion and pathogenesis, respectively. These nanomachines assemble and function using a type III secretion system (T3SS). Exported proteins are delivered to the export apparatus by dedicated cytoplasmic chaperones for their transport through the membrane. The structural and mechanistic basis of this process is poorly understood. Here we report the structures of two ternary complexes among flagellar chaperones (FliT and FliS), protein substrates (the filament-capping FliD and flagellin FliC), and the export gate platform protein FlhA. The substrates do not interact directly with FlhA; however, they are required to induce a binding-competent conformation to the chaperone that exposes the recognition motif featuring a highly conserved sequence recognized by FlhA. The structural data reveal the recognition signal in a class of T3SS proteins and provide new insight into the assembly of key protein complexes at the export gate. Bacterial flagella are composed of proteins secreted by a type III secretion system (T3SS), which requires the action of dedicated chaperones. Here, Xing et al. report the structures of two ternary complexes among flagellar chaperones, flagellar protein substrates, and the export gate platform protein.
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Affiliation(s)
- Qiong Xing
- Department of Structural Biology, St. Jude Children's Research Hospital, 263 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Ke Shi
- Department of Biochemistry, Molecular Biology & Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Athina Portaliou
- Laboratory of Molecular Bacteriology, Department of Microbiology & Immunology, Rega Institute for Medical Research, Katholicke Universiteit Leuven, 3000, Leuven, Belgium
| | - Paolo Rossi
- Department of Structural Biology, St. Jude Children's Research Hospital, 263 Danny Thomas Place, Memphis, TN, 38105, USA
| | - Anastassios Economou
- Laboratory of Molecular Bacteriology, Department of Microbiology & Immunology, Rega Institute for Medical Research, Katholicke Universiteit Leuven, 3000, Leuven, Belgium
| | - Charalampos G Kalodimos
- Department of Structural Biology, St. Jude Children's Research Hospital, 263 Danny Thomas Place, Memphis, TN, 38105, USA.
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43
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Salah Ud-Din AIM, Roujeinikova A. Flagellin glycosylation with pseudaminic acid in Campylobacter and Helicobacter: prospects for development of novel therapeutics. Cell Mol Life Sci 2018; 75:1163-1178. [PMID: 29080090 PMCID: PMC11105201 DOI: 10.1007/s00018-017-2696-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Revised: 10/10/2017] [Accepted: 10/24/2017] [Indexed: 02/08/2023]
Abstract
Many pathogenic bacteria require flagella-mediated motility to colonise and persist in their hosts. Helicobacter pylori and Campylobacter jejuni are flagellated epsilonproteobacteria associated with several human pathologies, including gastritis, acute diarrhea, gastric carcinoma and neurological disorders. In both species, glycosylation of flagellin with an unusual sugar pseudaminic acid (Pse) plays a crucial role in the biosynthesis of functional flagella, and thereby in bacterial motility and pathogenesis. Pse is found only in pathogenic bacteria. Its biosynthesis via six consecutive enzymatic steps has been extensively studied in H. pylori and C. jejuni. This review highlights the importance of flagella glycosylation and details structural insights into the enzymes in the Pse pathway obtained via a combination of biochemical, crystallographic, and mutagenesis studies of the enzyme-substrate and -inhibitor complexes. It is anticipated that understanding the underlying structural and molecular basis of the catalytic mechanisms of the Pse-synthesising enzymes will pave the way for the development of novel antimicrobials.
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Affiliation(s)
- Abu Iftiaf Md Salah Ud-Din
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia
| | - Anna Roujeinikova
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC, Australia.
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, VIC, Australia.
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44
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Desvaux M, Candela T, Serror P. Surfaceome and Proteosurfaceome in Parietal Monoderm Bacteria: Focus on Protein Cell-Surface Display. Front Microbiol 2018; 9:100. [PMID: 29491848 PMCID: PMC5817068 DOI: 10.3389/fmicb.2018.00100] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 01/16/2018] [Indexed: 12/12/2022] Open
Abstract
The cell envelope of parietal monoderm bacteria (archetypal Gram-positive bacteria) is formed of a cytoplasmic membrane (CM) and a cell wall (CW). While the CM is composed of phospholipids, the CW is composed at least of peptidoglycan (PG) covalently linked to other biopolymers, such as teichoic acids, polysaccharides, and/or polyglutamate. Considering the CW is a porous structure with low selective permeability contrary to the CM, the bacterial cell surface hugs the molecular figure of the CW components as a well of the external side of the CM. While the surfaceome corresponds to the totality of the molecules found at the bacterial cell surface, the proteinaceous complement of the surfaceome is the proteosurfaceome. Once translocated across the CM, secreted proteins can either be released in the extracellular milieu or exposed at the cell surface by associating to the CM or the CW. Following the gene ontology (GO) for cellular components, cell-surface proteins at the CM can either be integral (GO: 0031226), i.e., the integral membrane proteins, or anchored to the membrane (GO: 0046658), i.e., the lipoproteins. At the CW (GO: 0009275), cell-surface proteins can be covalently bound, i.e., the LPXTG-proteins, or bound through weak interactions to the PG or wall polysaccharides, i.e., the cell wall binding proteins. Besides monopolypeptides, some proteins can associate to each other to form supramolecular protein structures of high molecular weight, namely the S-layer, pili, flagella, and cellulosomes. After reviewing the cell envelope components and the different molecular mechanisms involved in protein attachment to the cell envelope, perspectives in investigating the proteosurfaceome in parietal monoderm bacteria are further discussed.
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Affiliation(s)
- Mickaël Desvaux
- Université Clermont Auvergne, INRA, UMR454 MEDiS, Clermont-Ferrand, France
| | - Thomas Candela
- EA4043 Unité Bactéries Pathogènes et Santé, Châtenay-Malabry, France
| | - Pascale Serror
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
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45
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Evans LDB, Bergen PM, Bryant OJ, Fraser GM. Interactions of Flagellar Structural Subunits with the Membrane Export Machinery. Methods Mol Biol 2018; 1593:17-35. [PMID: 28389942 DOI: 10.1007/978-1-4939-6927-2_2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
Abstract
During assembly of the bacterial flagellum, structural subunits synthesized inside the cell must be exported across the cytoplasmic membrane before they can crystallize into the nascent flagellar structure. This export process is facilitated by a specialized Flagellar Type III Secretion System (fT3SS) located at the base of each flagellum. Here, we describe three methods-isothermal titration calorimetry, photo-crosslinking using unnatural amino acids, and a subunit capture assay-used to investigate the interactions of flagellar structural subunits with the membrane export machinery component FlhB.
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Affiliation(s)
- Lewis D B Evans
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Paul M Bergen
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Owain J Bryant
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK
| | - Gillian M Fraser
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP, UK.
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46
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Loconte V, Kekez I, Matković-Čalogović D, Zanotti G. Structural characterization of FlgE2 protein fromHelicobacter pylorihook. FEBS J 2017; 284:4328-4342. [DOI: 10.1111/febs.14312] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/28/2017] [Accepted: 10/25/2017] [Indexed: 01/01/2023]
Affiliation(s)
| | - Ivana Kekez
- Divison of General and Inorganic Chemistry; Department of Chemistry; Faculty of Science; University of Zagreb; Croatia
| | - Dubravka Matković-Čalogović
- Divison of General and Inorganic Chemistry; Department of Chemistry; Faculty of Science; University of Zagreb; Croatia
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Mongiardini EJ, Quelas JI, Dardis C, Althabegoiti MJ, Lodeiro AR. Transcriptional Control of the Lateral-Flagellar Genes of Bradyrhizobium diazoefficiens. J Bacteriol 2017; 199:e00253-17. [PMID: 28533217 PMCID: PMC5512216 DOI: 10.1128/jb.00253-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Accepted: 05/16/2017] [Indexed: 11/20/2022] Open
Abstract
Bradyrhizobium diazoefficiens, a soybean N2-fixing symbiont, possesses a dual flagellar system comprising a constitutive subpolar flagellum and inducible lateral flagella. Here, we analyzed the genomic organization and biosynthetic regulation of the lateral-flagellar genes. We found that these genes are located in a single genomic cluster, organized in two monocistronic transcriptional units and three operons, one possibly containing an internal transcription start site. Among the monocistronic units is blr6846, homologous to the class IB master regulators of flagellum synthesis in Brucella melitensis and Ensifer meliloti and required for the expression of all the lateral-flagellar genes except lafA2, whose locus encodes a single lateral flagellin. We therefore named blr6846 lafR (lateral-flagellar regulator). Despite its similarity to two-component response regulators and its possession of a phosphorylatable Asp residue, lafR behaved as an orphan response regulator by not requiring phosphorylation at this site. Among the genes induced by lafR is flbTL , a class III regulator. We observed different requirements for FlbTL in the synthesis of each flagellin subunit. Although the accumulation of lafA1, but not lafA2, transcripts required FlbTL, the production of both flagellin polypeptides required FlbTL Moreover, the regulation cascade of this lateral-flagellar regulon appeared to be not as strictly ordered as those found in other bacterial species.IMPORTANCE Bacterial motility seems essential for the free-living style in the environment, and therefore these microorganisms allocate a great deal of their energetic resources to the biosynthesis and functioning of flagella. Despite energetic costs, some bacterial species possess dual flagellar systems, one of which is a primary system normally polar or subpolar, and the other is a secondary, lateral system that is produced only under special circumstances. Bradyrhizobium diazoefficiens, an N2-fixing symbiont of soybean plants, possesses dual flagellar systems, including the lateral system that contributes to swimming in wet soil and competition for nodulation and is expressed under high energy availability, as well as under requirement for high torque by the flagella. The structural organization and transcriptional regulation of the 41 genes that comprise this secondary flagellar system seem adapted to adjust bacterial energy expenditures for motility to the soil's environmental dynamics.
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Affiliation(s)
- Elías J Mongiardini
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT-La Plata, CONICET, La Plata, Argentina
| | - J Ignacio Quelas
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT-La Plata, CONICET, La Plata, Argentina
| | - Carolina Dardis
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT-La Plata, CONICET, La Plata, Argentina
| | - M Julia Althabegoiti
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT-La Plata, CONICET, La Plata, Argentina
| | - Aníbal R Lodeiro
- Instituto de Biotecnología y Biología Molecular, Facultad de Ciencias Exactas, Universidad Nacional de La Plata y CCT-La Plata, CONICET, La Plata, Argentina
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48
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Daum B, Vonck J, Bellack A, Chaudhury P, Reichelt R, Albers SV, Rachel R, Kühlbrandt W. Structure and in situ organisation of the Pyrococcus furiosus archaellum machinery. eLife 2017; 6. [PMID: 28653905 PMCID: PMC5517150 DOI: 10.7554/elife.27470] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/26/2017] [Indexed: 12/25/2022] Open
Abstract
The archaellum is the macromolecular machinery that Archaea use for propulsion or surface adhesion, enabling them to proliferate and invade new territories. The molecular composition of the archaellum and of the motor that drives it appears to be entirely distinct from that of the functionally equivalent bacterial flagellum and flagellar motor. Yet, the structure of the archaellum machinery is scarcely known. Using combined modes of electron cryo-microscopy (cryoEM), we have solved the structure of the Pyrococcus furiosus archaellum filament at 4.2 Å resolution and visualise the architecture and organisation of its motor complex in situ. This allows us to build a structural model combining the archaellum and its motor complex, paving the way to a molecular understanding of archaeal swimming motion.
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Affiliation(s)
- Bertram Daum
- Max Planck Institute of Biophysics, Frankfurt, Germany.,Living Systems Institute, University of Exeter, Exeter, United Kingdom.,College of Physics, Engineering and Physical Science, University of Exeter, Exeter, United Kingdom
| | - Janet Vonck
- Max Planck Institute of Biophysics, Frankfurt, Germany
| | - Annett Bellack
- Institute of Microbiology and Archaea Centre, University of Regensburg, Regensburg, Germany
| | - Paushali Chaudhury
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
| | - Robert Reichelt
- Institute of Microbiology and Archaea Centre, University of Regensburg, Regensburg, Germany
| | - Sonja-Verena Albers
- Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Freiburg, Germany
| | - Reinhard Rachel
- Institute of Microbiology and Archaea Centre, University of Regensburg, Regensburg, Germany
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49
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Radomska KA, Wösten MMSM, Ordoñez SR, Wagenaar JA, van Putten JPM. Importance of Campylobacter jejuni FliS and FliW in Flagella Biogenesis and Flagellin Secretion. Front Microbiol 2017; 8:1060. [PMID: 28659885 PMCID: PMC5466977 DOI: 10.3389/fmicb.2017.01060] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 05/29/2017] [Indexed: 12/11/2022] Open
Abstract
Flagella-driven motility enables bacteria to reach their favorable niche within the host. The human foodborne pathogen Campylobacter jejuni produces two heavily glycosylated structural flagellins (FlaA and FlaB) that form the flagellar filament. It also encodes the non-structural FlaC flagellin which is secreted through the flagellum and has been implicated in host cell invasion. The mechanisms that regulate C. jejuni flagellin biogenesis and guide the proteins to the export apparatus are different from those in most other enteropathogens and are not fully understood. This work demonstrates the importance of the putative flagellar protein FliS in C. jejuni flagella assembly. A constructed fliS knockout strain was non-motile, displayed reduced levels of FlaA/B and FlaC flagellin, and carried severely truncated flagella. Pull-down and Far Western blot assays showed direct interaction of FliS with all three C. jejuni flagellins (FlaA, FlaB, and FlaC). This is in contrast to, the sensor and regulator of intracellular flagellin levels, FliW, which bound to FlaA and FlaB but not to FlaC. The FliS protein but not FliW preferred binding to glycosylated C. jejuni flagellins rather than to their non-glycosylated recombinant counterparts. Mapping of the binding region of FliS and FliW using a set of flagellin fragments showed that the C-terminal subdomain of the flagellin was required for FliS binding, whereas the N-terminal subdomain was essential for FliW binding. The separate binding subdomains required for FliS and FliW, the different substrate specificity, and the differential preference for binding of glycosylated flagellins ensure optimal processing and assembly of the C. jejuni flagellins.
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Affiliation(s)
- Katarzyna A Radomska
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands
| | - Marc M S M Wösten
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands
| | - Soledad R Ordoñez
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands
| | - Jaap A Wagenaar
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands.,Wageningen Bioveterinary ResearchLelystad, Netherlands.,WHO Collaborating Centre for Campylobacter/OIE Reference Laboratory for CampylobacteriosisUtrecht, Netherlands
| | - Jos P M van Putten
- Department of Infectious Diseases and Immunology, Utrecht UniversityUtrecht, Netherlands.,WHO Collaborating Centre for Campylobacter/OIE Reference Laboratory for CampylobacteriosisUtrecht, Netherlands
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50
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Cho SY, Song WS, Hong HJ, Lee GS, Kang SG, Ko HJ, Kim PH, Yoon SI. Tetrameric structure of the flagellar cap protein FliD from Serratia marcescens. Biochem Biophys Res Commun 2017; 489:63-69. [PMID: 28527888 DOI: 10.1016/j.bbrc.2017.05.093] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 05/16/2017] [Indexed: 11/30/2022]
Abstract
Bacterial motility is provided by the flagellum. FliD is located at the distal end of the flagellum and plays a key role in the insertion of each flagellin protein at the growing tip of the flagellar filament. Because FliD functions as an oligomer, the determination of the oligomeric state of FliD is critical to understanding the molecular mechanism of FliD-mediated flagellar growth. FliD has been shown to adopt a pentameric or a hexameric structure depending on the bacterial species. Here, we report another distinct oligomeric form of FliD based on structural and biochemical studies. The crystal structures of the D2 and D3 domains of Serratia marcescens FliD (smFliD) were determined in two crystal forms and together revealed that smFliD assembles into a tetrameric architecture that resembles a four-pointed star plate. smFliD tetramerization was also confirmed in solution by cross-linking experiments. Although smFliD oligomerizes in a head-to-tail orientation using a common primary binding interface between the D2 and D3' domains (the prime denotes the second subunit in the oligomer) similarly to other FliD orthologs, the smFliD tetramer diverges to present a unique secondary D2-D2' binding interface. Our structure-based comparative analysis of FliD suggests that bacteria have developed diverse species-specific oligomeric forms of FliD that range from tetramers to hexamers for flagellar growth.
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Affiliation(s)
- So Yeon Cho
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Wan Seok Song
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Ho Jeong Hong
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Geun-Shik Lee
- College of Veterinary Medicine, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Seung Goo Kang
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Hyun-Jeong Ko
- Laboratory of Microbiology and Immunology, College of Pharmacy, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Pyeung-Hyeun Kim
- Department of Molecular Bioscience, School of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea
| | - Sung-Il Yoon
- Division of Biomedical Convergence, College of Biomedical Science, Kangwon National University, Chuncheon 24341, Republic of Korea; Institute of Bioscience and Biotechnology, Kangwon National University, Chuncheon 24341, Republic of Korea.
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