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Halte M, Andrianova EP, Goosmann C, Chevance FFV, Hughes KT, Zhulin IB, Erhardt M. FlhE functions as a chaperone to prevent formation of periplasmic flagella in Gram-negative bacteria. Nat Commun 2024; 15:5921. [PMID: 39004688 PMCID: PMC11247099 DOI: 10.1038/s41467-024-50278-0] [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: 03/25/2024] [Accepted: 07/04/2024] [Indexed: 07/16/2024] Open
Abstract
The bacterial flagellum, which facilitates motility, is composed of ~20 structural proteins organized into a long extracellular filament connected to a cytoplasmic rotor-stator complex via a periplasmic rod. Flagellum assembly is regulated by multiple checkpoints that ensure an ordered gene expression pattern coupled to the assembly of the various building blocks. Here, we use epifluorescence, super-resolution, and transmission electron microscopy to show that the absence of a periplasmic protein (FlhE) prevents proper flagellar morphogenesis and results in the formation of periplasmic flagella in Salmonella enterica. The periplasmic flagella disrupt cell wall synthesis, leading to a loss of normal cell morphology resulting in cell lysis. We propose that FlhE functions as a periplasmic chaperone to control assembly of the periplasmic rod, thus preventing formation of periplasmic flagella.
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Affiliation(s)
- Manuel Halte
- Institute of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany.
| | | | - Christian Goosmann
- Max Planck Institute for Infection Biology, Charitéplatz 1, 10117, Berlin, Germany
| | | | - Kelly T Hughes
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Igor B Zhulin
- Department of Microbiology, The Ohio State University, Columbus, OH, 43210, USA
| | - Marc Erhardt
- Institute of Biology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany.
- Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117, Berlin, Germany.
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2
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Unay J, Kint N, Viollier PH. Evolution of paralogous multicomponent systems for site-specific O-sialylation of flagellin in Gram-negative and Gram-positive bacteria. Curr Biol 2024; 34:2932-2947.e7. [PMID: 38897200 DOI: 10.1016/j.cub.2024.05.058] [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: 12/14/2023] [Revised: 05/13/2024] [Accepted: 05/24/2024] [Indexed: 06/21/2024]
Abstract
Many bacteria glycosylate flagellin on serine or threonine residues using pseudaminic acid (Pse) or other sialic acid-like donor sugars. Successful reconstitution of Pse-dependent sialylation by the conserved Maf-type flagellin glycosyltransferase (fGT) may require (a) missing component(s). Here, we characterize both Maf paralogs in the Gram-negative bacterium Shewanella oneidensis MR-1 and reconstitute Pse-dependent glycosylation in heterologous hosts. Remarkably, we uncovered distinct acceptor determinants and target specificities for each Maf. Whereas Maf-1 uses its C-terminal tetratricopeptide repeat (TPR) domain to confer flagellin acceptor and O-glycosylation specificity, Maf-2 requires the newly identified conserved specificity factor, glycosylation factor for Maf (GlfM), to form a ternary complex with flagellin. GlfM orthologs are co-encoded with Maf-2 in Gram-negative and Gram-positive bacteria and require an invariant aspartate in their four-helix bundle to function with Maf-2. Thus, convergent fGT evolution underlies distinct flagellin-binding modes in tripartite versus bipartite systems and, consequently, distinct O-glycosylation preferences of acceptor serine residues with Pse.
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Affiliation(s)
- Jovelyn Unay
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland
| | - Nicolas Kint
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland; Centre de Recherche des Cordeliers, Sorbonne Université, Inserm, Université Paris Cité, 75006 Paris, France
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine and Geneva Center for Inflammation Research (GCIR), Faculty of Medicine, University of Geneva, 1211 Geneva, Switzerland.
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3
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Halte M, Popp PF, Hathcock D, Severn J, Fischer S, Goosmann C, Ducret A, Charpentier E, Tu Y, Lauga E, Erhardt M, Renault TT. Bacterial motility depends on a critical flagellum length and energy-optimised assembly. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.28.599820. [PMID: 38979141 PMCID: PMC11230379 DOI: 10.1101/2024.06.28.599820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The flagellum is the most complex macromolecular structure known in bacteria and comprised of around two dozen distinct proteins. The main building block of the long, external flagellar filament, flagellin, is secreted through the flagellar type-III secretion system at a remarkable rate of several tens of thousands amino acids per second, significantly surpassing the rates achieved by other pore-based protein secretion systems. The evolutionary implications and potential benefits of this high secretion rate for flagellum assembly and function, however, have remained elusive. In this study, we provide both experimental and theoretical evidence that the flagellar secretion rate has been evolutionarily optimized to facilitate rapid and efficient construction of a functional flagellum. By synchronizing flagellar assembly, we found that a minimal filament length of 2.5 µm was required for swimming motility. Biophysical modelling revealed that this minimal filament length threshold resulted from an elasto-hydrodynamic instability of the whole swimming cell, dependent on the filament length. Furthermore, we developed a stepwise filament labeling method combined with electron microscopy visualization to validate predicted flagellin secretion rates of up to 10,000 amino acids per second. A biophysical model of flagellum growth demonstrates that the observed high flagellin secretion rate efficiently balances filament elongation and energy consumption, thereby enabling motility in the shortest amount of time. Taken together, these insights underscore the evolutionary pressures that have shaped the development and optimization of the flagellum and type-III secretion system, illuminating the intricate interplay between functionality and efficiency in assembly of large macromolecular structures. Significance statement Our study demonstrates how protein secretion of the bacterial flagellum is finely tuned to optimize filament assembly rate and flagellum function while minimizing energy consumption. By measuring flagellar filament lengths and bacterial swimming after initiation of flag-ellum assembly, we were able to establish the minimal filament length necessary for swimming motility, which we rationalized physically as resulting from an elasto-hydrodynamic instability of the swimming cell. Our bio-physical model of flagellum growth further illustrates how the physiological flagellin secretion rate is optimized to maximize filament elongation while conserving energy. These findings illuminate the evolutionary pressures that have shaped the function of the bacterial flagellum and type-III secretion system, driving improvements in bacterial motility and overall fitness.
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4
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Puri D, Allison KR. Escherichia coli self-organizes developmental rosettes. Proc Natl Acad Sci U S A 2024; 121:e2315850121. [PMID: 38814871 PMCID: PMC11161754 DOI: 10.1073/pnas.2315850121] [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: 09/12/2023] [Accepted: 05/01/2024] [Indexed: 06/01/2024] Open
Abstract
Rosettes are self-organizing, circular multicellular communities that initiate developmental processes, like organogenesis and embryogenesis, in complex organisms. Their formation results from the active repositioning of adhered sister cells and is thought to distinguish multicellular organisms from unicellular ones. Though common in eukaryotes, this multicellular behavior has not been reported in bacteria. In this study, we found that Escherichia coli forms rosettes by active sister-cell repositioning. After division, sister cells "fold" to actively align at the 2- and 4-cell stages of clonal division, thereby producing rosettes with characteristic quatrefoil configuration. Analysis revealed that folding follows an angular random walk, composed of ~1 µm strokes and directional randomization. We further showed that this motion was produced by the flagellum, the extracellular tail whose rotation generates swimming motility. Rosette formation was found to require de novo flagella synthesis suggesting it must balance the opposing forces of Ag43 adhesion and flagellar propulsion. We went on to show that proper rosette formation was required for subsequent morphogenesis of multicellular chains, rpoS gene expression, and formation of hydrostatic clonal-chain biofilms. Moreover, we found self-folding rosette-like communities in the standard motility assay, indicating that this behavior may be a general response to hydrostatic environments in E. coli. These findings establish self-organization of clonal rosettes by a prokaryote and have implications for evolutionary biology, synthetic biology, and medical microbiology.
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Affiliation(s)
- Devina Puri
- Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA30322
| | - Kyle R. Allison
- Department of Biomedical Engineering, Emory University and Georgia Institute of Technology, Atlanta, GA30322
- Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA30322
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5
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Fields JL, Zhang H, Bellis NF, Petersen HA, Halder SK, Rich-New ST, Wu H, Wang F. Structural diversity and clustering of bacterial flagellar outer domains. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.18.585621. [PMID: 38562817 PMCID: PMC10983879 DOI: 10.1101/2024.03.18.585621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Supercoiled flagellar filaments function as mechanical propellers within the bacterial flagellum complex, playing a crucial role in motility. Flagellin, the building block of the filament, features a conserved inner D0/D1 core domain across different bacterial species. In contrast, approximately half of the flagellins possess additional, highly divergent outer domain(s), suggesting varied functional potential. In this study, we elucidate atomic structures of flagellar filaments from three distinct bacterial species: Cupriavidus gilardii , Stenotrophomonas maltophilia , and Geovibrio thiophilus . Our findings reveal that the flagella from the facultative anaerobic G. thiophilus possesses a significantly more negatively charged surface, potentially enabling adhesion to positively charged minerals. Furthermore, we analyzed all AlphaFold predicted structures for annotated bacterial flagellins, categorizing the flagellin outer domains into 682 structural clusters. This classification provides insights into the prevalence and experimental verification of these outer domains. Remarkably, two of the flagellar structures reported herein belong to a previously unexplored cluster, indicating new opportunities on the study of the functional diversity of flagellar outer domains. Our findings underscore the complexity of bacterial flagellins and open up possibilities for future studies into their varied roles beyond motility.
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Halte M, Andrianova EP, Goosmann C, Chevance FFV, Hughes KT, Zhulin IB, Erhardt M. FlhE functions as a chaperone to prevent formation of periplasmic flagella in Gram-negative bacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.11.584431. [PMID: 38558991 PMCID: PMC10979839 DOI: 10.1101/2024.03.11.584431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The bacterial flagellum is an organelle utilized by many Gram-negative bacteria to facilitate motility. The flagellum is composed of a several µm long, extracellular filament that is connected to a cytoplasmic rotor-stator complex via a periplasmic rod. Composed of ∼20 structural proteins, ranging from a few subunits to several thousand building blocks, the flagellum is a paradigm of a complex macromolecular structure that utilizes a highly regulated assembly process. This process is governed by multiple checkpoints that ensure an ordered gene expression pattern coupled to the assembly of the various flagellar building blocks in order to produce a functional flagellum. Using epifluorescence, super-resolution STED and transmission electron microscopy, we discovered that in Salmonella , the absence of one periplasmic protein, FlhE, prevents proper flagellar morphogenesis and results in the formation of periplasmic flagella. The periplasmic flagella disrupt cell wall synthesis, leading to a loss of the standard cell morphology resulting in cell lysis. We propose a model where FlhE functions as a periplasmic chaperone to control assembly of the periplasmic rod to prevent formation of periplasmic flagella. Our results highlight that bacteria evolved sophisticated regulatory mechanisms to control proper flagellar assembly and minor deviations from this highly regulated process can cause dramatic physiological consequences.
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Armitage JP. Twists and turns: 40 years of investigating how and why bacteria swim. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001432. [PMID: 38363121 PMCID: PMC10924463 DOI: 10.1099/mic.0.001432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 01/23/2024] [Indexed: 02/17/2024]
Abstract
Fifty years of research has transformed our understanding of bacterial movement from one of description, based on a limited number of electron micrographs and some low-magnification studies of cells moving towards or away from chemical effectors, to probably the best understood behavioural system in biology. We have a molecular understanding of how bacteria sense and respond to changes in their environment and detailed structural insights into the workings of one of the most complex motor structures we know of. Thanks to advances in genomics we also understand how, through evolution, different species have tuned and adapted a core shared system to optimize behaviour in their specific environment. In this review, I will highlight some of the unexpected findings we made during my over 40-year career, how those findings changed some of our understanding of bacterial behaviour and biochemistry and some of the battles to have those observations accepted.
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Armitage JP. Microbial Primer: The bacterial flagellum - how bacteria swim. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001406. [PMID: 38226962 PMCID: PMC10866024 DOI: 10.1099/mic.0.001406] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/11/2023] [Indexed: 01/17/2024]
Abstract
Bacteria swim using membrane-spanning, electrochemical gradient-powered motors that rotate semi-rigid helical filaments. This primer provides a brief overview of the basic synthesis, structure and operation of these nanomachines. Details and variations on the basic system can be found in suggested further reading.
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Affiliation(s)
- Judith P. Armitage
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
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Minamino T, Kinoshita M. Structure, Assembly, and Function of Flagella Responsible for Bacterial Locomotion. EcoSal Plus 2023; 11:eesp00112023. [PMID: 37260402 PMCID: PMC10729930 DOI: 10.1128/ecosalplus.esp-0011-2023] [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: 01/18/2023] [Accepted: 04/14/2023] [Indexed: 01/28/2024]
Abstract
Many motile bacteria use flagella for locomotion under a variety of environmental conditions. Because bacterial flagella are under the control of sensory signal transduction pathways, each cell is able to autonomously control its flagellum-driven locomotion and move to an environment favorable for survival. The flagellum of Salmonella enterica serovar Typhimurium is a supramolecular assembly consisting of at least three distinct functional parts: a basal body that acts as a bidirectional rotary motor together with multiple force generators, each of which serves as a transmembrane proton channel to couple the proton flow through the channel with torque generation; a filament that functions as a helical propeller that produces propulsion; and a hook that works as a universal joint that transmits the torque produced by the rotary motor to the helical propeller. At the base of the flagellum is a type III secretion system that transports flagellar structural subunits from the cytoplasm to the distal end of the growing flagellar structure, where assembly takes place. In recent years, high-resolution cryo-electron microscopy (cryoEM) image analysis has revealed the overall structure of the flagellum, and this structural information has made it possible to discuss flagellar assembly and function at the atomic level. In this article, we describe what is known about the structure, assembly, and function of Salmonella flagella.
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Affiliation(s)
- Tohru Minamino
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
| | - Miki Kinoshita
- Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan
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10
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Botting JM, Tachiyama S, Gibson KH, Liu J, Starai VJ, Hoover TR. FlgV forms a flagellar motor ring that is required for optimal motility of Helicobacter pylori. PLoS One 2023; 18:e0287514. [PMID: 37976320 PMCID: PMC10655999 DOI: 10.1371/journal.pone.0287514] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/07/2023] [Indexed: 11/19/2023] Open
Abstract
Flagella-driven motility is essential for Helicobacter pylori to colonize the human stomach, where it causes a variety of diseases, including chronic gastritis, peptic ulcer disease, and gastric cancer. H. pylori has evolved a high-torque-generating flagellar motor that possesses several accessories not found in the archetypical Escherichia coli motor. FlgV was one of the first flagellar accessory proteins identified in Campylobacter jejuni, but its structure and function remain poorly understood. Here, we confirm that deletion of flgV in H. pylori B128 and a highly motile variant of H. pylori G27 (G27M) results in reduced motility in soft agar medium. Comparative analyses of in-situ flagellar motor structures of wild-type, ΔflgV, and a strain expressing FlgV-YFP showed that FlgV forms a ring-like structure closely associated with the junction of two highly conserved flagellar components: the MS and C rings. The results of our studies suggest that the FlgV ring has adapted specifically in Campylobacterota to support the assembly and efficient function of the high-torque-generating motors.
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Affiliation(s)
- Jack M. Botting
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Shoichi Tachiyama
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, United States of America
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Katherine H. Gibson
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Jun Liu
- Microbial Sciences Institute, Yale University, West Haven, Connecticut, United States of America
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, United States of America
| | - Vincent J. Starai
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
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Liang X, Wei F, Yang H, Fan L, Cai X, Ma Y, Shi J, Xing K, Qiu L, Li X, Lu L, Ji J, Wen Y, Feng J. Flagella-Driven Motility Is Critical to the Virulence of Xanthomonas fragariae in Strawberry. PLANT DISEASE 2023; 107:3506-3516. [PMID: 37157097 DOI: 10.1094/pdis-03-23-0409-re] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Xanthomonas fragariae (X. fragariae) is the causal agent of angular leaf spots (ALS) in strawberry plants. Recently, a study in China isolated X. fragariae strain YL19, which was observed to cause both typical ALS symptoms and dry cavity rot in strawberry crown tissue; this was the first X. fragariae strain to have both these effects in strawberry. In this study, from 2020 to 2022, we isolated 39 X. fragariae strains from diseased strawberries in different production areas in China. Multilocus sequence typing (MLST) and phylogenetic analysis showed that X. fragariae strain YLX21 was genetically different from YL19 and other strains. Tests indicated that YLX21 and YL19 had different pathogenicities toward strawberry leaves and stem crowns. YLX21 did not cause ALS symptoms, rarely caused dry cavity rot in strawberry crown after wound inoculation, and never caused dry cavity rot after spray inoculation, but it did cause severe ALS symptoms after spray inoculation. However, YL19 caused more severe symptoms in strawberry crowns under both conditions. Moreover, YL19 had a single polar flagellum, while YLX21 had no flagellum. Motility and chemotaxis assays showed that YLX21 had weaker motility than YL19, which may explain why YLX21 tended to multiply in situ within the strawberry leaf rather than migrate to other tissues, causing more severe ALS symptoms and mild crown rot symptoms. Taken together, the new strain YLX21 helped us reveal critical factors underlying the pathogenicity of X. fragariae and the mechanism by which dry cavity rot in strawberry crowns forms.
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Affiliation(s)
- Xia Liang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Feng Wei
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Hongliang Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Li Fan
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Xiaolin Cai
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Yangyang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Jiancheng Shi
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Kun Xing
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Lijuan Qiu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Xixuan Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Lijuan Lu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
| | - Jie Ji
- Institute of Plant Protection, Fujian Academy of Agriculture Sciences, Fuzhou 350013, Fujian, China
| | - Yingqiang Wen
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Jiayue Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Horticulture, Northwest A&F University, Yangling 712100, Shaanxi, China
- Key Laboratory of Protected Horticulture Engineering in Northwest China, Ministry of Agriculture and Rural Affairs, Yangling 712100, Shaanxi, China
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12
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Naseri G, Raasch H, Charpentier E, Erhardt M. A versatile regulatory toolkit of arabinose-inducible artificial transcription factors for Enterobacteriaceae. Commun Biol 2023; 6:1005. [PMID: 37789111 PMCID: PMC10547716 DOI: 10.1038/s42003-023-05363-3] [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: 05/31/2023] [Accepted: 09/15/2023] [Indexed: 10/05/2023] Open
Abstract
The Gram-negative bacteria Salmonella enterica and Escherichia coli are important model organisms, powerful prokaryotic expression platforms for biotechnological applications, and pathogenic strains constitute major public health threats. To facilitate new approaches for research and biotechnological applications, we here develop a set of arabinose-inducible artificial transcription factors (ATFs) using CRISPR/dCas9 and Arabidopsis-derived DNA-binding proteins to control gene expression in E. coli and Salmonella over a wide inducer concentration range. The transcriptional output of the different ATFs, in particular when expressed in Salmonella rewired for arabinose catabolism, varies over a wide spectrum (up to 35-fold gene activation). As a proof-of-concept, we use the developed ATFs to engineer a Salmonella two-input biosensor strain, SALSOR 0.2 (SALmonella biosenSOR 0.2), which detects and quantifies alkaloid drugs through a measurable fluorescent output. Moreover, we use plant-derived ATFs to regulate β-carotene biosynthesis in E. coli, resulting in ~2.1-fold higher β-carotene production compared to expression of the biosynthesis pathway using a strong constitutive promoter.
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Affiliation(s)
- Gita Naseri
- Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117, Berlin, Germany.
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany.
| | - Hannah Raasch
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117, Berlin, Germany
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany
| | - Marc Erhardt
- Max Planck Unit for the Science of Pathogens, Charitéplatz 1, 10117, Berlin, Germany.
- Institut für Biologie, Humboldt-Universität zu Berlin, Philippstrasse 13, 10115, Berlin, Germany.
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13
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Gibson KH, Botting JM, Al-Otaibi N, Maitre K, Bergeron J, Starai VJ, Hoover TR. Control of the flagellation pattern in Helicobacter pylori by FlhF and FlhG. J Bacteriol 2023; 205:e0011023. [PMID: 37655916 PMCID: PMC10521351 DOI: 10.1128/jb.00110-23] [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: 03/24/2023] [Accepted: 07/06/2023] [Indexed: 09/02/2023] Open
Abstract
FlhF and FlhG control the location and number of flagella, respectively, in many polar-flagellated bacteria. The roles of FlhF and FlhG are not well characterized in bacteria that have multiple polar flagella, such as Helicobacter pylori. Deleting flhG in H. pylori shifted the flagellation pattern where most cells had approximately four flagella to a wider and more even distribution in flagellar number. As reported in other bacteria, deleting flhF in H. pylori resulted in reduced motility, hypoflagellation, and the improper localization of flagella to nonpolar sites. Motile variants of H. pylori ∆flhF mutants that had a higher proportion of flagella localizing correctly to the cell pole were isolated, but we were unable to identify the genetic determinants responsible for the increased localization of flagella to the cell pole. One motile variant though produced more flagella than the ΔflhF parental strain, which apparently resulted from a missense mutation in fliF (encodes the MS ring protein), which changed Asn-255 to aspartate. Recombinant FliFN255D, but not recombinant wild-type FliF, formed ordered ring-like assemblies in vitro that were ~50 nm wide and displayed the MS ring architecture. We infer from these findings that the FliFN225D variant forms the MS ring more effectively in vivo in the absence of FlhF than wild-type FliF. IMPORTANCE Helicobacter pylori colonizes the human stomach where it can cause a variety of diseases, including peptic ulcer disease and gastric cancer. H. pylori uses flagella for motility, which is required for host colonization. FlhG and FlhF control the flagellation patterns in many bacteria. We found that in H. pylori, FlhG ensures that cells have approximately equal number of flagella and FlhF is needed for flagellum assembly and localization. FlhF is proposed to facilitate the assembly of FliF into the MS ring, which is one of the earliest structures formed in flagellum assembly. We identified a FliF variant that assembles the MS ring in the absence of FlhF, which supports the proposed role of FlhF in facilitating MS ring assembly.
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Affiliation(s)
| | - Jack M. Botting
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Natalie Al-Otaibi
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Kriti Maitre
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Julien Bergeron
- Randall Division of Cell and Molecular Biophysics, King’s College London, London, United Kingdom
| | - Vincent J. Starai
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
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14
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Sun G, Yu Z, Li Q, Zhang Y, Wang M, Liu Y, Liu J, Liu L, Yu X. Mechanism of Escherichia coli Lethality Caused by Overexpression of flhDC, the Flagellar Master Regulator Genes, as Revealed by Transcriptome Analysis. Int J Mol Sci 2023; 24:14058. [PMID: 37762361 PMCID: PMC10530849 DOI: 10.3390/ijms241814058] [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: 08/14/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 09/29/2023] Open
Abstract
The flhDC operon of Escherichia coli encodes a transcription factor that initiates flagella synthesis, elevates flagella construction and enhances cell motility, which all are energetically costly and highly regulated processes. In this study, we found that overexpression of flhDC genes from a strong regulatable pN15E6 plasmid could inhibit the growth of E. coli host cells and even eventually cause death. We used transcriptome analysis to investigate the mechanism of flhDC overexpression lethal to host bacteria. The results showed that a total of 568 differentially expressed genes (DEGs), including 378 up-regulated genes and 190 down-regulated genes were detected when the flhDC genes were over-expressed. Functional enrichment analysis results showed that the DEGs are related to a series of crucial biomolecular processes, including flagella synthesis, oxidative phosphorylation and pentose phosphate pathways, etc. We then examined, using RT-qPCR, the expression of key genes of the oxidative phosphorylation pathway at different time points after induction. Results showed that their expression increased in the early stage and decreased afterward, which was suggested to be the result of feedback on the overproduction of ROS, a strong side effect product of the elevated oxidative phosphorylation process. To further verify the level of ROS output, flhDC over-expressed bacteria cells were stained with DCHF-DA and a fluorescence signal was detected using flow cytometry. Results showed that the level of ROS output was higher in cells with over-expressed flhDC than in normal controls. Besides, we found upregulation of other genes (recN and zwf) that respond to ROS damage. This leads to the conclusion that the bacterial death led by the overexpression of flhDC genes is caused by damage from ROS overproduction, which leaked from the oxidative phosphorylation pathway.
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Affiliation(s)
- Guanglu Sun
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Zihao Yu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Qianwen Li
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Yuanxing Zhang
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Mingxiao Wang
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Yunhui Liu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Jinze Liu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Lei Liu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
| | - Xuping Yu
- Department of Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; (G.S.)
- Center for Veterinary Sciences, Zhejiang University, Hangzhou 310030, China
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15
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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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16
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Fernández-Colino A, Kiessling F, Slabu I, De Laporte L, Akhyari P, Nagel SK, Stingl J, Reese S, Jockenhoevel S. Lifelike Transformative Materials for Biohybrid Implants: Inspired by Nature, Driven by Technology. Adv Healthc Mater 2023; 12:e2300991. [PMID: 37290055 DOI: 10.1002/adhm.202300991] [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: 03/28/2023] [Revised: 05/25/2023] [Indexed: 06/10/2023]
Abstract
Today's living world is enriched with a myriad of natural biological designs, shaped by billions of years of evolution. Unraveling the construction rules of living organisms offers the potential to create new materials and systems for biomedicine. From the close examination of living organisms, several concepts emerge: hierarchy, pattern repetition, adaptation, and irreducible complexity. All these aspects must be tackled to develop transformative materials with lifelike behavior. This perspective article highlights recent progress in the development of transformative biohybrid systems for applications in the fields of tissue regeneration and biomedicine. Advances in computational simulations and data-driven predictions are also discussed. These tools enable the virtual high-throughput screening of implant design and performance before committing to fabrication, thus reducing the development time and cost of biomimetic and biohybrid constructs. The ongoing progress of imaging methods also constitutes an essential part of this matter in order to validate the computation models and enable longitudinal monitoring. Finally, the current challenges of lifelike biohybrid materials, including reproducibility, ethical considerations, and translation, are discussed. Advances in the development of lifelike materials will open new biomedical horizons, where perhaps what is currently envisioned as science fiction will become a science-driven reality in the future.
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Affiliation(s)
- Alicia Fernández-Colino
- Department of Biohybrid & Medical Textiles (BioTex), AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Forckenbeckstraße 55, 52074, Aachen, Germany
| | - Fabian Kiessling
- Institute for Experimental Molecular Imaging, Faculty of Medicine, RWTH Aachen University, Forckenbeckstraße 55, 52074, Aachen, Germany
| | - Ioana Slabu
- Institute of Applied Medical Engineering, Helmholtz Institute, Medical Faculty, RWTH Aachen University, Pauwelsstraße 20, 52074, Aachen, Germany
| | - Laura De Laporte
- DWI - Leibniz-Institute for Interactive Materials, Forckenbeckstraße 50, 52074, Aachen, Germany
- Institute of Technical and Macromolecular Chemistry (ITMC), RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany
- Advanced Materials for Biomedicine (AMB), Institute of Applied Medical Engineering (AME), University Hospital RWTH Aachen, Center for Biohybrid Medical Systems (CMBS), Forckenbeckstraße 55, 52074, Aachen, Germany
| | - Payam Akhyari
- Clinic for Cardiac Surgery, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Saskia K Nagel
- Applied Ethics Group, RWTH Aachen University, Theaterplatz 14, 52062, Aachen, Germany
| | - Julia Stingl
- Institute of Clinical Pharmacology, University Hospital RWTH Aachen, Wendlingweg 2, 52074, Aachen, Germany
| | - Stefanie Reese
- Institute of Applied Mechanics, RWTH Aachen University, Mies-van-der-Rohe-Str. 1, 52074, Aachen, Germany
| | - Stefan Jockenhoevel
- Department of Biohybrid & Medical Textiles (BioTex), AME-Institute of Applied Medical Engineering, Helmholtz Institute, RWTH Aachen University, Forckenbeckstraße 55, 52074, Aachen, Germany
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17
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Hu H, Popp PF, Santiveri M, Roa-Eguiara A, Yan Y, Martin FJO, Liu Z, Wadhwa N, Wang Y, Erhardt M, Taylor NMI. Ion selectivity and rotor coupling of the Vibrio flagellar sodium-driven stator unit. Nat Commun 2023; 14:4411. [PMID: 37500658 PMCID: PMC10374538 DOI: 10.1038/s41467-023-39899-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Accepted: 07/04/2023] [Indexed: 07/29/2023] Open
Abstract
Bacteria swim using a flagellar motor that is powered by stator units. Vibrio spp. are highly motile bacteria responsible for various human diseases, the polar flagella of which are exclusively driven by sodium-dependent stator units (PomAB). However, how ion selectivity is attained, how ion transport triggers the directional rotation of the stator unit, and how the stator unit is incorporated into the flagellar rotor remained largely unclear. Here, we have determined by cryo-electron microscopy the structure of Vibrio PomAB. The electrostatic potential map uncovers sodium binding sites, which together with functional experiments and molecular dynamics simulations, reveal a mechanism for ion translocation and selectivity. Bulky hydrophobic residues from PomA prime PomA for clockwise rotation. We propose that a dynamic helical motif in PomA regulates the distance between PomA subunit cytoplasmic domains, stator unit activation, and torque transmission. Together, our study provides mechanistic insights for understanding ion selectivity and rotor incorporation of the stator unit of the bacterial flagellum.
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Affiliation(s)
- Haidai Hu
- Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Philipp F Popp
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany
| | - Mònica Santiveri
- Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Aritz Roa-Eguiara
- Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Yumeng Yan
- Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Freddie J O Martin
- Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Zheyi Liu
- College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
- The Provincial International Science and Technology Cooperation Base on Engineering Biology, International Campus of Zhejiang University, Haining, 314400, China
| | - Navish Wadhwa
- Department of Physics, Arizona State University, Tempe, AZ, 85287, USA
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ, 85287, USA
| | - Yong Wang
- College of Life Sciences, Zhejiang University, Hangzhou, 310027, China
- The Provincial International Science and Technology Cooperation Base on Engineering Biology, International Campus of Zhejiang University, Haining, 314400, China
| | - Marc Erhardt
- Institute for Biology/Molecular Microbiology, Humboldt-Universität zu Berlin, Philippstr. 13, 10115, Berlin, Germany
- Max Planck Unit for the Science of Pathogens, Berlin, Germany
| | - Nicholas M I Taylor
- Structural Biology of Molecular Machines Group, Protein Structure & Function Program, Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
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18
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Sanchez JC, Montemayor EJ, Ploscariu NT, Parrell DD, Yang J, Sibert B, Cai K, Wright ER. Structural and Functional Analysis of Flagellar Filaments of Caulobacter crescentus. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2023; 29:920-921. [PMID: 37613764 DOI: 10.1093/micmic/ozad067.455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/25/2023]
Affiliation(s)
- Juan C Sanchez
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, WI, United States
- Biotechnology Training Program, University of Wisconsin-Madison, Madison, WI, United States
| | - Eric J Montemayor
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Nicoleta T Ploscariu
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Daniel D Parrell
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
| | - Jae Yang
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, United States
| | - Bryan Sibert
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, United States
| | - Kai Cai
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, United States
| | - Elizabeth R Wright
- Biophysics Graduate Program, University of Wisconsin-Madison, Madison, WI, United States
- Biotechnology Training Program, University of Wisconsin-Madison, Madison, WI, United States
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI, United States
- Cryo-Electron Microscopy Research Center, UW-Madison, Madison, WI, United States
- Morgridge Institute for Research, UW-Madison, Madison, WI, United States
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19
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Kaplan M, Yao Q, Jensen GJ. Structure and Assembly of the Proteus mirabilis Flagellar Motor by Cryo-Electron Tomography. Int J Mol Sci 2023; 24:8292. [PMID: 37176000 PMCID: PMC10179241 DOI: 10.3390/ijms24098292] [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: 03/27/2023] [Revised: 04/19/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Proteus mirabilis is a Gram-negative Gammaproteobacterium and a major causative agent of urinary tract infections in humans. It is characterized by its ability to switch between swimming motility in liquid media and swarming on solid surfaces. Here, we used cryo-electron tomography and subtomogram averaging to reveal the structure of the flagellar motor of P. mirabilis at nanometer resolution in intact cells. We found that P. mirabilis has a motor that is structurally similar to those of Escherichia coli and Salmonella enterica, lacking the periplasmic elaborations that characterize other more specialized gammaproteobacterial motors. In addition, no density corresponding to stators was present in the subtomogram average suggesting that the stators are dynamic. Finally, several assembly intermediates of the motor were seen that support the inside-out assembly pathway.
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Affiliation(s)
- Mohammed Kaplan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Qing Yao
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Grant J. Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
- Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84604, USA
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20
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Nedeljković M, Kreutzberger MAB, Postel S, Bonsor D, Xing Y, Jacob N, Schuler WJ, Egelman EH, Sundberg EJ. An unbroken network of interactions connecting flagellin domains is required for motility in viscous environments. PLoS Pathog 2023; 19:e1010979. [PMID: 37253071 PMCID: PMC10256154 DOI: 10.1371/journal.ppat.1010979] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 06/09/2023] [Accepted: 05/08/2023] [Indexed: 06/01/2023] Open
Abstract
In its simplest form, bacterial flagellar filaments are composed of flagellin proteins with just two helical inner domains, which together comprise the filament core. Although this minimal filament is sufficient to provide motility in many flagellated bacteria, most bacteria produce flagella composed of flagellin proteins with one or more outer domains arranged in a variety of supramolecular architectures radiating from the inner core. Flagellin outer domains are known to be involved in adhesion, proteolysis and immune evasion but have not been thought to be required for motility. Here we show that in the Pseudomonas aeruginosa PAO1 strain, a bacterium that forms a ridged filament with a dimerization of its flagellin outer domains, motility is categorically dependent on these flagellin outer domains. Moreover, a comprehensive network of intermolecular interactions connecting the inner domains to the outer domains, the outer domains to one another, and the outer domains back to the inner domain filament core, is required for motility. This inter-domain connectivity confers PAO1 flagella with increased stability, essential for its motility in viscous environments. Additionally, we find that such ridged flagellar filaments are not unique to Pseudomonas but are, instead, present throughout diverse bacterial phyla.
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Affiliation(s)
- Marko Nedeljković
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Mark A. B. Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Sandra Postel
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Daniel Bonsor
- Institute of Human Virology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Yingying Xing
- School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Neil Jacob
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - William J. Schuler
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Edward H. Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, United States of America
| | - Eric J. Sundberg
- Department of Biochemistry, Emory University School of Medicine, Atlanta, Georgia, United States of America
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21
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Liauw CM, Vaidya M, Slate AJ, Hickey NA, Ryder S, Martínez-Periñán E, McBain AJ, Banks CE, Whitehead KA. Analysis of Cellular Damage Resulting from Exposure of Bacteria to Graphene Oxide and Hybrids Using Fourier Transform Infrared Spectroscopy. Antibiotics (Basel) 2023; 12:antibiotics12040776. [PMID: 37107138 PMCID: PMC10135141 DOI: 10.3390/antibiotics12040776] [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: 03/08/2023] [Revised: 04/11/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023] Open
Abstract
With the increase in antimicrobial resistance, there is an urgent need to find new antimicrobials. Four particulate antimicrobial compounds, graphite (G), graphene oxide (GO), silver-graphene oxide (Ag-GO) and zinc oxide-graphene oxide (ZnO-GO) were tested against Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The antimicrobial effects on the cellular ultrastructure were determined using Fourier transform infrared spectroscopy (FTIR), and selected FTIR spectral metrics correlated with cell damage and death arising from exposure to the GO hybrids. Ag-GO caused the most severe damage to the cellular ultrastructure, whilst GO caused intermediate damage. Graphite exposure caused unexpectedly high levels of damage to E. coli, whereas ZnO-GO exposure led to relatively low levels of damage. The Gram-negative bacteria demonstrated a stronger correlation between FTIR metrics, indicated by the perturbation index and the minimal bactericidal concentration (MBC). The blue shift of the combined ester carbonyl and amide I band was stronger for the Gram-negative varieties. FTIR metrics tended to provide a better assessment of cell damage based on correlation with cellular imaging and indicated that damage to the lipopolysaccharide, peptidoglycan and phospholipid bilayers had occurred. Further investigations into the cell damage caused by the GO-based materials will allow the development of this type of carbon-based multimode antimicrobials.
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Affiliation(s)
- Christopher M Liauw
- Microbiology at Interfaces Group, School of Healthcare Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
| | - Misha Vaidya
- Microbiology at Interfaces Group, School of Healthcare Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
| | - Anthony J Slate
- Department of Life Sciences, University of Bath, Claverton Down, Bath BA2 7AY, UK
| | - Niall A Hickey
- Microbiology at Interfaces Group, School of Healthcare Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
| | - Steven Ryder
- Microbiology at Interfaces Group, School of Healthcare Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
| | - Emiliano Martínez-Periñán
- Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Andrew J McBain
- School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester M13 9PT, UK
| | - Craig E Banks
- Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
| | - Kathryn A Whitehead
- Microbiology at Interfaces Group, School of Healthcare Sciences, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK
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22
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Zhuang XY, Tseng CK, Lo CJ. Live-Cell Imaging of the Assembly and Ejection Processes of the Bacterial Flagella by Fluorescence Microscopy. Methods Mol Biol 2023; 2646:35-42. [PMID: 36842104 DOI: 10.1007/978-1-0716-3060-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Bacterial flagella are molecular machines used for motility and chemotaxis. The flagellum consists of a thin extracellular helical filament as a propeller, a short hook as a universal joint, and a basal body as a rotary motor. The filament is made up of more than 20,000 flagellin molecules and can grow to several micrometers long but only 20 nanometers thick. The regulation of flagellar assembly and ejection is important for bacterial environmental adaptation. However, due to the technical difficulty to observe these nanostructures in live cells, our understanding of the flagellar growth and loss is limited. In the last three decades, the development of fluorescence microscopy and fluorescence labeling of specific cellular structure has made it possible to perform the real-time observation of bacterial flagellar assembly and ejection processes. Furthermore, flagella are not only critical for bacterial motility but also important antigens stimulating host immune responses. The complete understanding of bacterial flagellar production and ejection is valuable for understanding macromolecular self-assembly, cell adaptation, and pathogen-host interactions.
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Affiliation(s)
- Xiang-Yu Zhuang
- Department of Physics, National Central University, Taoyuan, Taiwan
| | - Chao-Kai Tseng
- Department of Physics, National Central University, Taoyuan, Taiwan
| | - Chien-Jung Lo
- Department of Physics, National Central University, Taoyuan, Taiwan. .,Center for Complex Systems, National Central University, Taoyuan, Taiwan.
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23
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Terashima H, Homma M, Kojima S. Site-Directed Cross-Linking Between Bacterial Flagellar Motor Proteins In Vivo. Methods Mol Biol 2023; 2646:71-82. [PMID: 36842107 DOI: 10.1007/978-1-0716-3060-0_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
The bacterial flagellum employs a rotary motor embedded on the cell surface. The motor consists of the stator and rotor elements and is driven by ion influx (typically H+ or Na+) through an ion channel of the stator. Ion influx induces conformational changes in the stator, followed by changes in the interactions between the stator and rotor. The driving force to rotate the flagellum is thought to be generated by changing the stator-rotor interactions. In this chapter, we describe two methods for investigating the interactions between the stator and rotor: site-directed in vivo photo-crosslinking and site-directed in vivo cysteine disulfide crosslinking.
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Affiliation(s)
- Hiroyuki Terashima
- Department of Bacteriology, Institute of Tropical Medicine (NEKKEN), Nagasaki University, Nagasaki, Japan.
| | - Michio Homma
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Seiji Kojima
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
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Kojima S, Homma M, Kandori H. Purification of the Na +-Driven PomAB Stator Complex and Its Analysis Using ATR-FTIR Spectroscopy. Methods Mol Biol 2023; 2646:95-107. [PMID: 36842109 DOI: 10.1007/978-1-0716-3060-0_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
The flagellar motor of marine Vibrio is driven by the sodium-motive force across the inner membrane. The stator complex, consisting of two membrane proteins PomA and PomB, is responsible for energy conversion in the motor. To understand the coupling of the Na+ flux with torque generation, it is essential to clearly identify the Na+-binding sites and the Na+ flux pathway through the stator channel. Although residues essential for Na+ flux have been identified by using mutational analysis, it has been difficult to observe Na+ binding to the PomAB stator complex. Here we describe a method to monitor the binding of Na+ to purified PomAB stator complex using attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. This method demonstrates that Na+-binding sites are formed by critical aspartic acid and threonine residues located in the transmembrane segments of PomAB.
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Affiliation(s)
- Seiji Kojima
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.
| | - Michio Homma
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Hideki Kandori
- Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Nagoya, Japan.
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25
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Oliveira NCD, Cônsoli FL. Dysbiosis of the larval gut microbiota of Spodoptera frugiperda strains feeding on different host plants. Symbiosis 2023. [DOI: 10.1007/s13199-023-00907-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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26
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Myers BK, Shin GY, Agarwal G, Stice SP, Gitaitis RD, Kvitko BH, Dutta B. Genome-wide association and dissociation studies in Pantoea ananatis reveal potential virulence factors affecting Allium porrum and Allium fistulosum × Allium cepa hybrid. Front Microbiol 2023; 13:1094155. [PMID: 36817114 PMCID: PMC9933511 DOI: 10.3389/fmicb.2022.1094155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/30/2022] [Indexed: 02/05/2023] Open
Abstract
Pantoea ananatis is a member of a Pantoea species complex that causes center rot of bulb onions (A. cepa) and also infects other Allium crops like leeks (Allium porrum), chives (Allium schoenoprasum), bunching onion or Welsh onion (Allium fistulosum), and garlic (Allium sativum). This pathogen relies on a chromosomal phosphonate biosynthetic gene cluster (HiVir) and a plasmid-borne thiosulfinate tolerance cluster (alt) for onion pathogenicity and virulence, respectively. However, pathogenicity and virulence factors associated with other Allium species remain unknown. We used phenotype-dependent genome-wide association (GWAS) and phenotype-independent gene-pair coincidence (GPC) analyses on a panel of diverse 92 P. ananatis strains, which were inoculated on A. porrum and A. fistulosum × A. cepa under greenhouse conditions. Phenotypic assays showed that, in general, these strains were more aggressive on A. fistulosum × A. cepa as opposed to A. porrum. Of the 92 strains, only six showed highly aggressive foliar lesions on A. porrum compared to A. fistulosum × A. cepa. Conversely, nine strains showed highly aggressive foliar lesions on A. fistulosum × A. cepa compared to A. porrum. These results indicate that there are underlying genetic components in P. ananatis that may drive pathogenicity in these two Allium spp. Based on GWAS for foliar pathogenicity, 835 genes were associated with P. ananatis' pathogenicity on A. fistulosum × A. cepa whereas 243 genes were associated with bacterial pathogenicity on A. porrum. The Hivir as well as the alt gene clusters were identified among these genes. Besides the 'HiVir' and the alt gene clusters that are known to contribute to pathogenicity and virulence from previous studies, genes annotated with functions related to stress responses, a potential toxin-antitoxin system, flagellar-motility, quorum sensing, and a previously described phosphonoglycan biosynthesis (pgb) cluster were identified. The GPC analysis resulted in the identification of 165 individual genes sorted into 39 significant gene-pair association components and 255 genes sorted into 50 significant gene-pair dissociation components. Within the coincident gene clusters, several genes that occurred on the GWAS outputs were associated with each other but dissociated with genes that did not appear in their respective GWAS output. To focus on candidate genes that could explain the difference in virulence between hosts, a comparative genomics analysis was performed on five P. ananatis strains that were differentially pathogenic on A. porrum or A. fistulosum × A. cepa. Here, we found a putative type III secretion system, and several other genes that occurred on both GWAS outputs of both Allium hosts. Further, we also demonstrated utilizing mutational analysis that the pepM gene in the HiVir cluster is important than the pepM gene in the pgb cluster for P. ananatis pathogenicity in A. fistulosum × A. cepa and A. porrum. Overall, our results support that P. ananatis may utilize a common set of genes or gene clusters to induce symptoms on A. fistulosum × A. cepa foliar tissue as well as A. cepa but implicates additional genes for infection on A. porrum.
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Affiliation(s)
- Brendon K. Myers
- Department of Plant Pathology, The University of Georgia, Tifton, GA, United States
| | - Gi Yoon Shin
- Department of Plant Pathology, The University of Georgia, Athens, GA, United States
| | - Gaurav Agarwal
- Department of Plant Pathology, The University of Georgia, Tifton, GA, United States
| | - Shaun P. Stice
- Department of Plant Pathology, The University of Georgia, Athens, GA, United States
| | - Ronald D. Gitaitis
- Department of Plant Pathology, The University of Georgia, Tifton, GA, United States
| | - Brian H. Kvitko
- Department of Plant Pathology, The University of Georgia, Athens, GA, United States
| | - Bhabesh Dutta
- Department of Plant Pathology, The University of Georgia, Tifton, GA, United States,*Correspondence: Bhabesh Dutta, ✉
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Yang D, Zhao L, Li Q, Huang L, Qin Y, Wang P, Zhu C, Yan Q. flgC gene is involved in the virulence regulation of Pseudomonas plecoglossicida and affects the immune response of Epinephelus coioides. FISH & SHELLFISH IMMUNOLOGY 2023; 132:108512. [PMID: 36587883 DOI: 10.1016/j.fsi.2022.108512] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 12/19/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
As a pathogen of cultured teleosts, Pseudomonas plecoglossicida has caused significant economic losses. flgC plays an important role in encoding flagellar basal-body rod proteins. Our previous studies revealed the high expression of P. plecoglossicida flgC in infected Epinephelus coioides. To explore the role of flgC in the virulence of P. plecoglossicida and the immune response of E. coioides to the infection of P. plecoglossicida, flgC gene of P. plecoglossicida was knocked down by RNA interference (RNAi). The results showed that the flgC gene in all four mutants of P. plecoglossicida was significantly knocked down, and the mutant with the best knockdown efficiency of 94.3% was selected for subsequent studies. Compared with the NZBD9 strain of P. plecoglossicida, the flgC-RNAi strain showed a significantly decrease in chemotaxis, motility, adhesion, and biofilm formation. Furthermore, compared with the E. coioides infected with the NZBD9 strain, the infection of flgC-RNAi strain resulted in the infected E. coioides a 1.5-day delay in the time of first death and an 80% increase in survival rate, far fewer white nodules upon the spleen surfaces, and lower pathogen load in the spleens. RNAi of flgC significantly influenced the metabolome and transcriptome of the spleen in infected E. coioides. KEGG enrichment analysis exhibited that the Toll-like receptor signaling pathway was the most enriched immune pathway; the most significantly enriched metabolic pathways were associated with Linoleic acid metabolism, Choline metabolism in cancer, and Glycerophospholipid metabolism. Further combined analysis of transcriptome and metabolome indicated significant correlations among pantothenate and CoA biosynthesis, beta-alanine metabolism, lysosome metabolites, and related genes. These results suggested that flgC was a pathogenic gene of P. plecoglossicida; flgC was associated with the regulation of chemotaxis, motility, biofilm formation, and adhesion; flgC influenced the immune response of E. coioides to the infection of P. plecoglossicida.
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Affiliation(s)
- Dou Yang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lingmin Zhao
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Qi Li
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Lixing Huang
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Yingxue Qin
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China
| | - Pan Wang
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou, Fujian, 363503, China
| | - Chuanzhong Zhu
- Key Laboratory of Aquatic Functional Feed and Environmental Regulation of Fujian Province, Fujian Dabeinong Aquatic Sci. & Tech. Co., Ltd., Zhangzhou, Fujian, 363503, China
| | - Qingpi Yan
- Fisheries College, Jimei University, Xiamen, Fujian, 361021, China.
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Involvement of Flagellin in Kin Recognition between Bacillus velezensis Strains. mSystems 2022; 7:e0077822. [PMID: 36218362 PMCID: PMC9764977 DOI: 10.1128/msystems.00778-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Kin discrimination in nature is an effective way for bacteria to stabilize population cooperation and maintain progeny benefits. However, so far, the research on kin discrimination for Bacillus still has concentrated on "attack and defense" between cells and diffusion-dependent molecular signals of quorum sensing, kin recognition in Bacillus, however, has not been reported. To determine whether flagellar is involve in the kin recognition of Bacillus, we constructed Bacillus velezensis SQR9 assembled with flagellin of its kin and non-kin strains, and performed a swarm boundary assay with SQR9, then analyzed sequence variation of flagellin and other flagellar structural proteins in B. velezensis genus. Our results showed that SQR9 assembled with flagellin of non-kin strains was more likely to form a border phenotype with wild-type strain SQR9 in swarm assay than that of kin strains, and that non-kin strains had greater variation in flagellin than kin strains. In B. velezensis, these variations in flagellin were prevalent and had evolved significantly faster than other flagellar structural proteins. Therefore, we proposed that flagellin is an effective tool partly involved in the kin recognition of B. velezensis strains. IMPORTANCE Kin selection plays an important role in stabilizing population cooperation and maintaining the progeny benefits for bacteria in nature. However, to date, the role of flagellin in kin recognition in Bacillus has not been reported. By using rhizospheric Bacillus velezensis SQR9, we accomplished flagellin region interchange among its related strains, and show that flagellin acts as a mediator to distinguish kin from non-kin in B. velezensis. We demonstrated the polymorphism of flagellin in B. velezensis through alignment analysis of flagellin protein sequences. Therefore, it was proposed that flagellin was likely to be an effective tool for mediating kin recognition in B. velezensis.
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Wang X, Blumenfeld R, Feng XQ, Weitz DA. 'Phase transitions' in bacteria - From structural transitions in free living bacteria to phenotypic transitions in bacteria within biofilms. Phys Life Rev 2022; 43:98-138. [PMID: 36252408 DOI: 10.1016/j.plrev.2022.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 09/30/2022] [Indexed: 12/05/2022]
Abstract
Phase transitions are common in inanimate systems and have been studied extensively in natural sciences. Less explored are the rich transitions that take place at the micro- and nano-scales in biological systems. In conventional phase transitions, large-scale properties of the media change discontinuously in response to continuous changes in external conditions. Such changes play a significant role in the dynamic behaviours of organisms. In this review, we focus on some transitions in both free-living and biofilms of bacteria. Particular attention is paid to the transitions in the flagellar motors and filaments of free-living bacteria, in cellular gene expression during the biofilm growth, in the biofilm morphology transitions during biofilm expansion, and in the cell motion pattern transitions during the biofilm formation. We analyse the dynamic characteristics and biophysical mechanisms of these phase transition phenomena and point out the parallels between these transitions and conventional phase transitions. We also discuss the applications of some theoretical and numerical methods, established for conventional phase transitions in inanimate systems, in bacterial biofilms.
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Affiliation(s)
- Xiaoling Wang
- School of Mechanical Engineering, University of Science and Technology Beijing, Beijing 100083, China; John A. Paulson School of Engineering and Applied Sciences, Harvard University, 9 Oxford St, Cambridge, MA, 02138, USA.
| | - Raphael Blumenfeld
- Gonville & Caius College, University of Cambridge, Trinity St., Cambridge CB2 1TA, UK
| | - Xi-Qiao Feng
- Institute of Biomechanics and Medical Engineering, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China
| | - David A Weitz
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, 9 Oxford St, Cambridge, MA, 02138, USA; Department of Physics, Harvard University, 9 Oxford St, Cambridge, MA, 02138, USA
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Outer membrane protein of OmpF contributes to swimming motility, biofilm formation, osmotic response as well as the transcription of maltose metabolic genes in Citrobacter werkmanii. World J Microbiol Biotechnol 2022; 39:15. [PMID: 36401137 DOI: 10.1007/s11274-022-03458-3] [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: 09/05/2022] [Accepted: 11/02/2022] [Indexed: 11/20/2022]
Abstract
Bacterial outer membrane proteins (Omps) are essential for environmental sensing, stress responses, and substance transport. Our previous study discovered that OmpA contributes to planktonic growth, biocide resistance, biofilm formation, and swimming motility in Citrobacter werkmanii, whereas the molecular functions of OmpF in this strain are largely unknown. Thus, in this study, the ompF gene was firstly knocked out from the genome of C. werkmanii using a homologous recombination method, and its phenotypical alternations of ∆ompF were then thoroughly characterized using biochemical and molecular approaches with the parental wild type (WT) and complementary (∆ompF-com) strains. The results demonstrated that the swimming ability of ∆ompF on semi-solid plates was reduced compared to WT due to the down-regulation of flgC, flgH, fliK, and fliF. Meanwhile, ompF deletion reduces biofilm formation on both glass and polystyrene surfaces due to decreased cell aggregation. Furthermore, ompF inactivation induced different osmotic stress (carbon sources and metal ions) responses in its biofilms when compared to WT and ∆ompF-com. Finally, a total of 6 maltose metabolic genes of lamB, malE, malK, malG, malM, and malF were all up-regulated in ∆ompF. The gene knockout and HPLC results revealed that the MalEFGK2 cluster was primarily responsible for maltose transport in C. werkmanii. Furthermore, we discovered for the first time that the upstream promoter of OmpF and its transcription can be combined with and negatively regulated by MalT. Overall, OmpF plays a role in a variety of biochemical processes and molecular functions in C. werkmanii, and it may even act as a targeted site to inhibit biofilm formation.
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Chen J, Zou Y, Zheng T, Huang S, Guo L, Lin J, Zheng Q. The in Vitro Fermentation of Cordyceps militaris Polysaccharides Changed the Simulated Gut Condition and Influenced Gut Bacterial Motility and Translocation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2022; 70:14193-14204. [PMID: 36305603 DOI: 10.1021/acs.jafc.2c05785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
The motility ability of intestinal lipopolysaccharide (LPS)-producing bacteria determines their translocation to the enterohepatic circulation and works as an infectious complication. In this study, the health effects of Cordyceps militaris polysaccharides (CMPs) were re-evaluated based on whether these polysaccharides could affect the motility of gut commensal LPS-producing bacteria and impede their translocation. The results showed that CMP-m fermentation in the gut could change the chemical environment, leading to a decrease in velocity and a shift in the motility pattern. Further study suggested that detachment/fragmentation of flagella, decreased motor forces, and changed chemical conditions might account for this weakened motility. The adhesion and invasion abilities of gut bacteria were also reduced, with lower expression of virulence-related genes. These results indicated that the health regulation effects of CMP-m might be through decreasing the motility of LPS-producing bacteria, hindering their translocation and therefore reducing the LPS level in the enterohepatic circulation.
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Affiliation(s)
- Jieming Chen
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
| | - Yuan Zou
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
| | - Taotao Zheng
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
| | - Shishi Huang
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
| | - Liqiong Guo
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
| | - Junfang Lin
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
| | - Qianwang Zheng
- Institute of Food Biotechnology and College of Food Science, South China Agricultural University, Guangzhou, Guangdong 510640, China
- Research Center for Micro-Ecological Agent Engineering and Technology of Guangdong Province, Guangzhou 510640, China
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32
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The Assembly of Flagella in Enteropathogenic Escherichia coli Requires the Presence of a Functional Type III Secretion System. Int J Mol Sci 2022; 23:ijms232213705. [PMID: 36430181 PMCID: PMC9694695 DOI: 10.3390/ijms232213705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
In enteropathogenic Escherichia coli (EPEC), the production of flagella and the type III secretion system (T3SS) is activated in the presence of host cultured epithelial cells. The goal of this study was to investigate the relationship between expression of flagella and the T3SS. Mutants deficient in assembling T3SS basal and translocon components (ΔespA, ΔespB, ΔespD, ΔescC, ΔescN, and ΔescV), and in secreting effector molecules (ΔsepD and ΔsepL) were tested for flagella production under several growth conditions. The ΔespA mutant did not produce flagella in any condition tested, although fliC was transcribed. The remaining mutants produced different levels of flagella upon growth in LB or in the presence of cells but were significantly diminished in flagella production after growth in Dulbecco's minimal essential medium. We also investigated the role of virulence and global regulator genes in expression of flagella. The ΔqseB and ΔqseC mutants produced abundant flagella only when growing in LB and in the presence of HeLa cells, indicating that QseB and QseC act as negative regulators of fliC transcription. The ΔgrlR, ΔperA, Δler, Δhns, and Δfis mutants produced low levels of flagella, suggesting these regulators are activators of fliC expression. These data suggest that the presence of an intact T3SS is required for assembly of flagella highlighting the existence in EPEC of a cross-talk between these two virulence-associated T3SSs.
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FliL Differentially Interacts with Two Stator Systems To Regulate Flagellar Motor Output in Pseudomonas aeruginosa. Appl Environ Microbiol 2022; 88:e0153922. [PMID: 36286538 PMCID: PMC9680632 DOI: 10.1128/aem.01539-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
FliL emerged as a modulator of flagellar motor function in several bacterial species, but its function in
Pseudomonas aeruginosa
was unknown. Here, by performing single-motor studies using a bead assay, we elucidated its effects on the flagellar motor in
P. aeruginosa
.
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Gibson K, Chu JK, Zhu S, Nguyen D, Mrázek J, Liu J, Hoover TR. A Tripartite Efflux System Affects Flagellum Stability in Helicobacter pylori. Int J Mol Sci 2022; 23:ijms231911609. [PMID: 36232924 PMCID: PMC9570263 DOI: 10.3390/ijms231911609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/23/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
Helicobacter pylori uses a cluster of polar, sheathed flagella for swimming motility. A search for homologs of H. pylori proteins that were conserved in Helicobacter species that possess flagellar sheaths but were underrepresented in Helicobacter species with unsheathed flagella identified several candidate proteins. Four of the identified proteins are predicted to form part of a tripartite efflux system that includes two transmembrane domains of an ABC transporter (HP1487 and HP1486), a periplasmic membrane fusion protein (HP1488), and a TolC-like outer membrane efflux protein (HP1489). Deleting hp1486/hp1487 and hp1489 homologs in H. pylori B128 resulted in reductions in motility and the number of flagella per cell. Cryo-electron tomography studies of intact motors of the Δhp1489 and Δhp1486/hp1487 mutants revealed many of the cells contained a potential flagellum disassembly product consisting of decorated L and P rings, which has been reported in other bacteria. Aberrant motors lacking specific components, including a cage-like structure that surrounds the motor, were also observed in the Δhp1489 mutant. These findings suggest a role for the H. pylori HP1486-HP1489 tripartite efflux system in flagellum stability. Three independent variants of the Δhp1486/hp1487 mutant with enhanced motility were isolated. All three motile variants had the same frameshift mutation in fliL, suggesting a role for FliL in flagellum disassembly.
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Affiliation(s)
- Katherine Gibson
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Joshua K. Chu
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Shiwei Zhu
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA
| | - Doreen Nguyen
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Jan Mrázek
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Institute of Bioinformatics, University of Georgia, Athens, GA 30602, USA
| | - Jun Liu
- Microbial Sciences Institute, Yale University, West Haven, CT 06516, USA
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, CT 06536, USA
| | - Timothy R. Hoover
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
- Correspondence: ; Tel.: +1-706-542-2675
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Kreutzberger MAB, Sonani RR, Liu J, Chatterjee S, Wang F, Sebastian AL, Biswas P, Ewing C, Zheng W, Poly F, Frankel G, Luisi BF, Calladine CR, Krupovic M, Scharf BE, Egelman EH. Convergent evolution in the supercoiling of prokaryotic flagellar filaments. Cell 2022; 185:3487-3500.e14. [PMID: 36057255 PMCID: PMC9500442 DOI: 10.1016/j.cell.2022.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 07/04/2022] [Accepted: 08/04/2022] [Indexed: 02/02/2023]
Abstract
The supercoiling of bacterial and archaeal flagellar filaments is required for motility. Archaeal flagellar filaments have no homology to their bacterial counterparts and are instead homologs of bacterial type IV pili. How these prokaryotic flagellar filaments, each composed of thousands of copies of identical subunits, can form stable supercoils under torsional stress is a fascinating puzzle for which structural insights have been elusive. Advances in cryoelectron microscopy (cryo-EM) make it now possible to directly visualize the basis for supercoiling, and here, we show the atomic structures of supercoiled bacterial and archaeal flagellar filaments. For the bacterial flagellar filament, we identify 11 distinct protofilament conformations with three broad classes of inter-protomer interface. For the archaeal flagellar filament, 10 protofilaments form a supercoil geometry supported by 10 distinct conformations, with one inter-protomer discontinuity creating a seam inside of the curve. Our results suggest that convergent evolution has yielded stable superhelical geometries that enable microbial locomotion.
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Affiliation(s)
- Mark A B Kreutzberger
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Ravi R Sonani
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Junfeng Liu
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Archaeal Virology Unit, 75015 Paris, France
| | - Sharanya Chatterjee
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, London, UK
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Amanda L Sebastian
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Priyanka Biswas
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, London, UK
| | - Cheryl Ewing
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA
| | - Weili Zheng
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA
| | - Frédéric Poly
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD 20910, USA
| | - Gad Frankel
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College London, London, UK
| | - B F Luisi
- Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge CB2 1GA, UK
| | - Chris R Calladine
- Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ, UK
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, CNRS UMR 6047, Archaeal Virology Unit, 75015 Paris, France
| | - Birgit E Scharf
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA 22903, USA.
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Discovery of a Novel Inner Membrane-Associated Bacterial Structure Related to the Flagellar Type III Secretion System. J Bacteriol 2022; 204:e0014422. [PMID: 35862756 PMCID: PMC9380563 DOI: 10.1128/jb.00144-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The bacterial flagellar type III secretion system (fT3SS) is a suite of membrane-embedded and cytoplasmic proteins responsible for building the flagellar motility machinery. Homologous nonflagellar (NF-T3SS) proteins form the injectisome machinery that bacteria use to deliver effector proteins into eukaryotic cells, and other family members were recently reported to be involved in the formation of membrane nanotubes. Here, we describe a novel, evolutionarily widespread, hat-shaped structure embedded in the inner membranes of bacteria, of yet-unidentified function, that is present in species containing fT3SS. Mutant analysis suggests a relationship between this novel structure and the fT3SS, but not the NF-T3SS. While the function of this novel structure remains unknown, we hypothesize that either some of the fT3SS proteins assemble within the hat-like structure, perhaps including the fT3SS core complex, or that fT3SS components regulate other proteins that form part of this novel structure. IMPORTANCE The type III secretion system (T3SS) is a fascinating suite of proteins involved in building diverse macromolecular systems, including the bacterial flagellar motility machine, the injectisome machinery that bacteria use to inject effector proteins into host cells, and probably membrane nanotubes which connect bacterial cells. Here, we accidentally discovered a novel inner membrane-associated complex related to the flagellar T3SS. Examining our lab database, which is comprised of more than 40,000 cryo-tomograms of dozens of species, we discovered that this novel structure is both ubiquitous and ancient, being present in highly divergent classes of bacteria. Discovering a novel, widespread structure related to what are among the best-studied molecular machines in bacteria will open new venues for research aiming at understanding the function and evolution of T3SS proteins.
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Deficiency of exopolysaccharides and O-antigen makes Halomonas bluephagenesis self-flocculating and amenable to electrotransformation. Commun Biol 2022; 5:623. [PMID: 35750760 PMCID: PMC9232590 DOI: 10.1038/s42003-022-03570-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 06/08/2022] [Indexed: 11/17/2022] Open
Abstract
Halomonas bluephagenesis, a haloalkaliphilic bacterium and native polyhydroxybutyrate (PHB) producer, is a non-traditional bioproduction chassis for the next generation industrial biotechnology (NGIB). A single-sgRNA CRISPR/Cas9 genome editing tool is optimized using dual-sgRNA strategy to delete large DNA genomic fragments (>50 kb) with efficiency of 12.5% for H. bluephagenesis. The non-essential or redundant gene clusters of H. bluephagenesis, including those encoding flagella, exopolysaccharides (EPSs) and O-antigen, are sequentially deleted using this improved genome editing strategy. Totally, ~3% of the genome is reduced with its rapid growth and high PHB-production ability unaffected. The deletion of EPSs and O-antigen gene clusters shows two excellent properties from industrial perspective. Firstly, the EPSs and O-antigen deleted mutant rapidly self-flocculates and precipitates within 20 min without centrifugation. Secondly, DNA transformation into the mutant using electroporation becomes feasible compared to the wild-type H. bluephagenesis. The genome-reduced H. bluephagenesis mutant reduces energy and carbon source requirement to synthesize PHB comparable to its wild type. The H. bluephagenesis chassis with a reduced genome serves as an improved version of a NGIB chassis for productions of polyhydroxyalkanoates (PHA) or other chemicals. CRISPR/Cas9 editing of a PHB-producing H. bluephagenesis strain is used to delete the redundant synthesis pathways of flagella and EPSs, allowing for enhanced self-flocculation, less carbon and energy requirement for metabolic processes and feasible electrotransformation.
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Chen Y, Lv M, Liang Z, Liu Z, Zhou J, Zhang L. Cyclic di-GMP modulates sessile-motile phenotypes and virulence in Dickeya oryzae via two PilZ domain receptors. MOLECULAR PLANT PATHOLOGY 2022; 23:870-884. [PMID: 35254732 PMCID: PMC9104268 DOI: 10.1111/mpp.13200] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 01/23/2022] [Accepted: 02/08/2022] [Indexed: 05/03/2023]
Abstract
Dickeya oryzae is a bacterial pathogen causing the severe rice stem rot disease in China and other rice-growing countries. We showed recently that the universal bacterial second messenger c-di-GMP plays an important role in modulation of bacterial motility and pathogenicity, but the mechanism of regulation remains unknown. In this study, bioinformatics analysis of the D. oryzae EC1 genome led to the identification of two proteins, YcgR and BcsA, both of which contain a conserved c-di-GMP receptor domain, known as the PilZ-domain. By deleting all the genes encoding c-di-GMP-degrading enzymes in D. oryzae EC1, the resultant mutant 7ΔPDE with high c-di-GMP levels became nonmotile, formed hyperbiofilm, and lost the ability to colonize and invade rice seeds. These phenotypes were partially reversed by deletion of ycgR in the mutant 7ΔPDE, whereas deletion of bcsA only reversed the hyperbiofilm phenotype of mutant 7ΔPDE. Significantly, double deletion of ycgR and bcsA in mutant 7ΔPDE rescued its motility, biofilm formation, and virulence to levels of wild-type EC1. In vitro biochemical experiments and in vivo phenotypic assays further validated that YcgR and BcsA proteins are the receptors for c-di-GMP, which together play a critical role in regulating the c-di-GMP-associated functionality. The findings from this study fill a gap in our understanding of how c-di-GMP modulates bacterial motility and biofilm formation, and provide useful clues for further elucidation of sophisticated virulence regulatory mechanisms in this important plant pathogen.
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Affiliation(s)
- Yufan Chen
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlIntegrative Microbiology Research CenterSouth China Agricultural UniversityGuangzhouChina
| | - Mingfa Lv
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlIntegrative Microbiology Research CenterSouth China Agricultural UniversityGuangzhouChina
| | - Zhibin Liang
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlIntegrative Microbiology Research CenterSouth China Agricultural UniversityGuangzhouChina
| | - Zhiqing Liu
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlIntegrative Microbiology Research CenterSouth China Agricultural UniversityGuangzhouChina
| | - Jianuan Zhou
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlIntegrative Microbiology Research CenterSouth China Agricultural UniversityGuangzhouChina
| | - Lian‐Hui Zhang
- Guangdong Laboratory for Lingnan Modern AgricultureGuangzhouChina
- Guangdong Province Key Laboratory of Microbial Signals and Disease ControlIntegrative Microbiology Research CenterSouth China Agricultural UniversityGuangzhouChina
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Minamino T, Kinoshita M, Namba K. Insight Into Distinct Functional Roles of the Flagellar ATPase Complex for Flagellar Assembly in Salmonella. Front Microbiol 2022; 13:864178. [PMID: 35602071 PMCID: PMC9114704 DOI: 10.3389/fmicb.2022.864178] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 04/13/2022] [Indexed: 11/13/2022] Open
Abstract
Most motile bacteria utilize the flagellar type III secretion system (fT3SS) to construct the flagellum, which is a supramolecular motility machine consisting of basal body rings and an axial structure. Each axial protein is translocated via the fT3SS across the cytoplasmic membrane, diffuses down the central channel of the growing flagellar structure and assembles at the distal end. The fT3SS consists of a transmembrane export complex and a cytoplasmic ATPase ring complex with a stoichiometry of 12 FliH, 6 FliI and 1 FliJ. This complex is structurally similar to the cytoplasmic part of the FOF1 ATP synthase. The export complex requires the FliH12-FliI6-FliJ1 ring complex to serve as an active protein transporter. The FliI6 ring has six catalytic sites and hydrolyzes ATP at an interface between FliI subunits. FliJ binds to the center of the FliI6 ring and acts as the central stalk to activate the export complex. The FliH dimer binds to the N-terminal domain of each of the six FliI subunits and anchors the FliI6-FliJ1 ring to the base of the flagellum. In addition, FliI exists as a hetero-trimer with the FliH dimer in the cytoplasm. The rapid association-dissociation cycle of this hetero-trimer with the docking platform of the export complex promotes sequential transfer of export substrates from the cytoplasm to the export gate for high-speed protein transport. In this article, we review our current understanding of multiple roles played by the flagellar cytoplasmic ATPase complex during efficient flagellar assembly.
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Affiliation(s)
- Tohru Minamino
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Miki Kinoshita
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
| | - Keiichi Namba
- Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan.,RIKEN SPring-8 Center and Center for Biosystems Dynamics Research, Osaka, Japan.,JEOL YOKOGUSHI Research Alliance Laboratories, Osaka University, Osaka, Japan
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Kaplan M, Oikonomou CM, Wood CR, Chreifi G, Subramanian P, Ortega DR, Chang Y, Beeby M, Shaffer CL, Jensen GJ. Novel transient cytoplasmic rings stabilize assembling bacterial flagellar motors. EMBO J 2022; 41:e109523. [PMID: 35301732 PMCID: PMC9108667 DOI: 10.15252/embj.2021109523] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 01/31/2022] [Accepted: 02/16/2022] [Indexed: 12/20/2022] Open
Abstract
The process by which bacterial cells build their intricate flagellar motility apparatuses has long fascinated scientists. Our understanding of this process comes mainly from studies of purified flagella from two species, Escherichia coli and Salmonella enterica. Here, we used electron cryo-tomography (cryo-ET) to image the assembly of the flagellar motor in situ in diverse Proteobacteria: Hylemonella gracilis, Helicobacter pylori, Campylobacter jejuni, Pseudomonas aeruginosa, Pseudomonas fluorescens, and Shewanella oneidensis. Our results reveal the in situ structures of flagellar intermediates, beginning with the earliest flagellar type III secretion system core complex (fT3SScc) and MS-ring. In high-torque motors of Beta-, Gamma-, and Epsilon-proteobacteria, we discovered novel cytoplasmic rings that interact with the cytoplasmic torque ring formed by FliG. These rings, associated with the MS-ring, assemble very early and persist until the stators are recruited into their periplasmic ring; in their absence the stator ring does not assemble. By imaging mutants in Helicobacter pylori, we found that the fT3SScc proteins FliO and FliQ are required for the assembly of these novel cytoplasmic rings. Our results show that rather than a simple accretion of components, flagellar motor assembly is a dynamic process in which accessory components interact transiently to assist in building the complex nanomachine.
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Affiliation(s)
- Mohammed Kaplan
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Catherine M Oikonomou
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Cecily R Wood
- Department of Veterinary ScienceUniversity of KentuckyLexingtonKYUSA
| | - Georges Chreifi
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Poorna Subramanian
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Davi R Ortega
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
| | - Yi‐Wei Chang
- Department of Biochemistry and BiophysicsPerelman School of MedicineUniversity of PennsylvaniaPhiladelphiaPAUSA
| | - Morgan Beeby
- Department of Life SciencesImperial College LondonLondonUK
| | - Carrie L Shaffer
- Department of Veterinary ScienceUniversity of KentuckyLexingtonKYUSA
- Department of Microbiology, Immunology, and Molecular GeneticsUniversity of KentuckyLexingtonKYUSA
- Department of Pharmaceutical SciencesUniversity of KentuckyLexingtonKYUSA
| | - Grant J Jensen
- Division of Biology and Biological EngineeringCalifornia Institute of TechnologyPasadenaCAUSA
- Department of Chemistry and BiochemistryBrigham Young UniversityProvoUTUSA
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Avelino-Flores F, Soria-Bustos J, Saldaña-Ahuactzi Z, Martínez-Laguna Y, Yañez-Santos JA, Cedillo-Ramírez ML, Girón JA. The Transcription of Flagella of Enteropathogenic Escherichia coli O127:H6 Is Activated in Response to Environmental and Nutritional Signals. Microorganisms 2022; 10:microorganisms10040792. [PMID: 35456842 PMCID: PMC9032864 DOI: 10.3390/microorganisms10040792] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 03/23/2022] [Accepted: 03/23/2022] [Indexed: 02/01/2023] Open
Abstract
The flagella of enteropathogenic Escherichia coli (EPEC) O127:H6 E2348/69 mediate adherence to host proteins and epithelial cells. What environmental and nutritional signals trigger or down-regulate flagella expression in EPEC are largely unknown. In this study, we analyzed the influence of pH, oxygen tension, cationic and anionic salts (including bile salt), carbon and nitrogen sources, and catecholamines on the expression of the flagellin gene (fliC) of E2348/69. We found that sodium bicarbonate, which has been shown to induce the expression of type III secretion effectors, down-regulated flagella expression, explaining why E2348/69 shows reduced motility and flagellation when growing in Dulbecco’s Minimal Essential Medium (DMEM). Further, growth under a 5% carbon dioxide atmosphere, in DMEM adjusted to pH 8.2, in M9 minimal medium supplemented with 80 mM glucose or sucrose, and in DMEM containing 150 mM sodium chloride, 0.1% sodium deoxycholate, or 30 µM epinephrine significantly enhanced fliC transcription to different levels in comparison to growth in DMEM alone. When EPEC was grown in the presence of HeLa cells or in supernatants of cultured HeLa cells, high levels (4-fold increase) of fliC transcription were detected in comparison to growth in DMEM alone. Our data suggest that nutritional and host signals that EPEC may encounter in the intestinal niche activate fliC expression in order to favor motility and host colonization.
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Affiliation(s)
- Fabiola Avelino-Flores
- Centro de Investigación en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570, Mexico; (F.A.-F.); (Y.M.-L.)
| | - Jorge Soria-Bustos
- Instituto de Ciencias de la Salud, Universidad Autónoma del Estado de Hidalgo, Pachuca 42160, Mexico;
| | - Zeus Saldaña-Ahuactzi
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA;
| | - Ygnacio Martínez-Laguna
- Centro de Investigación en Ciencias Microbiológicas, Benemérita Universidad Autónoma de Puebla, Puebla 72570, Mexico; (F.A.-F.); (Y.M.-L.)
| | - Jorge A. Yañez-Santos
- Facultad de Estomatología, Benemérita Universidad Autónoma de Puebla, Puebla 72410, Mexico;
| | - María L. Cedillo-Ramírez
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla 72592, Mexico;
| | - Jorge A. Girón
- Centro de Detección Biomolecular, Benemérita Universidad Autónoma de Puebla, Puebla 72592, Mexico;
- Correspondence:
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Role of the flagellar hook in the structural development and antibiotic tolerance of Pseudomonas aeruginosa biofilms. THE ISME JOURNAL 2022; 16:1176-1186. [PMID: 34880458 PMCID: PMC8940932 DOI: 10.1038/s41396-021-01157-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/10/2021] [Accepted: 11/16/2021] [Indexed: 12/16/2022]
Abstract
Pseudomonas aeruginosa biofilms exhibit an intrinsic resistance to antibiotics and constitute a considerable clinical threat. In cystic fibrosis, a common feature of biofilms formed by P. aeruginosa in the airway is the occurrence of mutants deficient in flagellar motility. This study investigates the impact of flagellum deletion on the structure and antibiotic tolerance of P. aeruginosa biofilms, and highlights a role for the flagellum in adaptation and cell survival during biofilm development. Mutations in the flagellar hook protein FlgE influence greatly P. aeruginosa biofilm structuring and antibiotic tolerance. Phenotypic analysis of the flgE knockout mutant compared to the wild type (WT) reveal increased fitness under planktonic conditions, reduced initial adhesion but enhanced formation of microcolony aggregates in a microfluidic environment, and decreased expression of genes involved in exopolysaccharide formation. Biofilm cells of the flgE knock-out mutant display enhanced tolerance towards multiple antibiotics, whereas its planktonic cells show similar resistance to the WT. Confocal microscopy of biofilms demonstrates that gentamicin does not affect the viability of cells located in the inner part of the flgE knock-out mutant biofilms due to reduced penetration. These findings suggest that deficiency in flagellar proteins like FlgE in biofilms and in cystic fibrosis infections represent phenotypic and evolutionary adaptations that alter the structure of P. aeruginosa biofilms conferring increased antibiotic tolerance.
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Molecular Characterization of Three Tandemly Located Flagellin Genes of Stenotrophomonas maltophilia. Int J Mol Sci 2022; 23:ijms23073863. [PMID: 35409223 PMCID: PMC8998449 DOI: 10.3390/ijms23073863] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 01/25/2023] Open
Abstract
Stenotrophomonas maltophilia is a motile, opportunistic pathogen. The flagellum, which is involved in swimming, swarming, adhesion, and biofilm formation, is considered a virulence factor for motile pathogens. Three flagellin genes, fliC1, fliC2, and fliC3, were identified from the sequenced S. maltophilia genome. FliC1, fliC2, and fliC3 formed an operon, and their encoding proteins shared 67–82% identity. Members of the fliC1C2C3 operon were deleted individually or in combination to generate single mutants, double mutants, and a triple mutant. The contributions of the three flagellins to swimming, swarming, flagellum morphology, adhesion, and biofilm formation were assessed. The single mutants generally had a compromise in swimming and no significant defects in swarming, adhesion on biotic surfaces, and biofilm formation on abiotic surfaces. The double mutants displayed obvious defects in swimming and adhesion on abiotic and biotic surfaces. The flagellin-null mutant lost swimming ability and was compromised in adhesion and biofilm formation. All tested mutants demonstrated substantial but different flagellar morphologies, supporting that flagellin composition affects filament morphology. Bacterial swimming motility was significantly compromised under an oxidative stress condition, irrespective of flagellin composition. Collectively, the utilization of these three flagellins for filament assembly equips S. maltophilia with flagella adapted to provide better ability in swimming, adhesion, and biofilm formation for its pathogenesis.
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Akahoshi DT, Bevins CL. Flagella at the Host-Microbe Interface: Key Functions Intersect With Redundant Responses. Front Immunol 2022; 13:828758. [PMID: 35401545 PMCID: PMC8987104 DOI: 10.3389/fimmu.2022.828758] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 02/21/2022] [Indexed: 12/15/2022] Open
Abstract
Many bacteria and other microbes achieve locomotion via flagella, which are organelles that function as a swimming motor. Depending on the environment, flagellar motility can serve a variety of beneficial functions and confer a fitness advantage. For example, within a mammalian host, flagellar motility can provide bacteria the ability to resist clearance by flow, facilitate access to host epithelial cells, and enable travel to nutrient niches. From the host’s perspective, the mobility that flagella impart to bacteria can be associated with harmful activities that can disrupt homeostasis, such as invasion of epithelial cells, translocation across epithelial barriers, and biofilm formation, which ultimately can decrease a host’s reproductive fitness from a perspective of natural selection. Thus, over an evolutionary timescale, the host developed a repertoire of innate and adaptive immune countermeasures that target and mitigate this microbial threat. These countermeasures are wide-ranging and include structural components of the mucosa that maintain spatial segregation of bacteria from the epithelium, mechanisms of molecular recognition and inducible responses to flagellin, and secreted effector molecules of the innate and adaptive immune systems that directly inhibit flagellar motility. While much of our understanding of the dynamics of host-microbe interaction regarding flagella is derived from studies of enteric bacterial pathogens where flagella are a recognized virulence factor, newer studies have delved into host interaction with flagellated members of the commensal microbiota during homeostasis. Even though many aspects of flagellar motility may seem innocuous, the host’s redundant efforts to stop bacteria in their tracks highlights the importance of this host-microbe interaction.
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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: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 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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Jia J, Ford E, Hobbs SM, Baird SM, Lu SE. Occidiofungin Is the Key Metabolite for Antifungal Activity of the Endophytic Bacterium Burkholderia sp. MS455 Against Aspergillus flavus. PHYTOPATHOLOGY 2022; 112:481-491. [PMID: 34433293 DOI: 10.1094/phyto-06-21-0225-r] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aflatoxin is a secondary metabolite produced by Aspergillus fungi and presents a major food safety concern globally. Among the available methods for prevention and control of aflatoxin, the application of antifungal bacteria has gained favor in recent years. An endophytic bacterium MS455, isolated from soybean, exhibited broad-spectrum antifungal activity against economically important pathogens, including Aspergillus flavus. MS455 was identified as a strain of Burkholderia based on genomic analysis. Random and site-specific mutations were used in discovery of the genes that share high homology to the ocf gene cluster of Burkholderia contaminans strain MS14, which is responsible for production of the antifungal compound occidiofungin. RNA sequencing analysis demonstrated that ORF1, a homolog to the ambR1 LuxR-type regulatory gene, regulates occidiofungin biosynthesis in MS455. Additionally, 284 differentially expressed genes, including 138 upregulated and 146 downregulated genes, suggesting that, in addition to its role in occidiofungin production, ORF1 is involved in expression of multiple genes, especially those involved in ornibactin biosynthesis. Plate bioassays showed the growth of A. flavus was significantly inhibited by the wild-type strain MS455 as compared with the ORF1 mutant. Similarly, corn kernel assays showed that growth of A. flavus and aflatoxin production were reduced significantly by MS455 as compared with buffer control and the ORF1 mutant. Collectively, the results demonstrated that production of occidiofungin is essential for antifungal activity of the endophytic bacterium MS455. This research has provided insights about antifungal mechanisms of MS455 and development of biological approaches to prevent aflatoxin contamination in plant production.
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Affiliation(s)
- Jiayuan Jia
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762
| | - Emerald Ford
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762
| | - Sarah M Hobbs
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762
| | - Sonya M Baird
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762
| | - Shi-En Lu
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762
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Castledine M, Padfield D, Sierocinski P, Soria Pascual J, Hughes A, Mäkinen L, Friman VP, Pirnay JP, Merabishvili M, de Vos D, Buckling A. Parallel evolution of Pseudomonas aeruginosa phage resistance and virulence loss in response to phage treatment in vivo and in vitro. eLife 2022; 11:73679. [PMID: 35188102 PMCID: PMC8912922 DOI: 10.7554/elife.73679] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 02/20/2022] [Indexed: 12/02/2022] Open
Abstract
With rising antibiotic resistance, there has been increasing interest in treating pathogenic bacteria with bacteriophages (phage therapy). One limitation of phage therapy is the ease at which bacteria can evolve resistance. Negative effects of resistance may be mitigated when resistance results in reduced bacterial growth and virulence, or when phage coevolves to overcome resistance. Resistance evolution and its consequences are contingent on the bacteria-phage combination and their environmental context, making therapeutic outcomes hard to predict. One solution might be to conduct ‘in vitro evolutionary simulations’ using bacteria-phage combinations from the therapeutic context. Overall, our aim was to investigate parallels between in vitro experiments and in vivo dynamics in a human participant. Evolutionary dynamics were similar, with high levels of resistance evolving quickly with limited evidence of phage evolution. Resistant bacteria—evolved in vitro and in vivo—had lower virulence. In vivo, this was linked to lower growth rates of resistant isolates, whereas in vitro phage resistant isolates evolved greater biofilm production. Population sequencing suggests resistance resulted from selection on de novo mutations rather than sorting of existing variants. These results highlight the speed at which phage resistance can evolve in vivo, and how in vitro experiments may give useful insights for clinical evolutionary outcomes.
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Affiliation(s)
- Meaghan Castledine
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
| | - Daniel Padfield
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
| | - Pawel Sierocinski
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
| | - Jesica Soria Pascual
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
| | - Adam Hughes
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
| | - Lotta Mäkinen
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
| | | | - Jean-Paul Pirnay
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Maya Merabishvili
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Daniel de Vos
- Laboratory for Molecular and Cellular Technology, Queen Astrid Military Hospital, Brussels, Belgium
| | - Angus Buckling
- College of Life and Environmental Sciences, University of Exeter, Penryn, United Kingdom
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48
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Two Flagellar mutants of Xanthomonas campestris are characterized by enhanced xanthan production and higher xanthan viscosity. J Biotechnol 2022; 347:9-17. [DOI: 10.1016/j.jbiotec.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 02/04/2022] [Accepted: 02/08/2022] [Indexed: 11/20/2022]
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49
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Choe Y, Lee D, Seong M, Yoon JB, Yang JH, Yang JY, Moon KH, Kang HY. Characterization of Edwardsiella piscicida CK108 flagellin genes and evaluation of their potential as vaccine targets in the zebrafish model. JOURNAL OF FISH DISEASES 2022; 45:249-259. [PMID: 34843109 DOI: 10.1111/jfd.13550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 10/20/2021] [Accepted: 10/21/2021] [Indexed: 06/13/2023]
Abstract
The control of bacterial pathogens, including Edwardsiella piscicida, in the aquaculture industry has high economic importance. This study aimed to identify a potential live vaccine candidate against E. piscicida infection to minimize the side effects and elicit immunity in the host. This study evaluated the virulence factors of E. piscicida CK108, with a special focus on the flagella. E. piscicida has two important homologous flagellin genes, namely flagellin-associated protein (fap) and flagellin domain-containing protein (fdp). CK226 (Δfap), CK247 (Δfdp) and CK248 (Δfap, fdp) mutant strains were constructed. Both CK226 and CK247 displayed decreased length and thickness of flagellar filaments, resulting in reduced bacterial swimming motility, while CK248 was non-motile as it lacked flagella. The loss of flagella and decreased motility was expected to decrease the pathogenicity of CK248. However, the median lethal dose (LD50 ) of CK248 against zebrafish was lower than those of the wild-type, CK226 and CK247 strains. The protective immunity and cytokine gene expression levels in the CK248-infected zebrafish were lower than those in the wild type-infected zebrafish. In conclusion, Fap and Fdp are essential for flagella formation and motility, and for stimulating fish immune response, which can be utilized as a potential adjuvants for E. piscicida vaccination.
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Affiliation(s)
- Yunjeong Choe
- Department of Microbiology, Pusan National University, Busan, Korea
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
| | - Donghee Lee
- Department of Microbiology, Pusan National University, Busan, Korea
- Department of Microbiology and Immunology, East Carolina University, Greenville, North Carolina, USA
| | - Minji Seong
- Department of Microbiology, Pusan National University, Busan, Korea
- Laboratory Animal Center, Daegu-Gyeongbuk Medical Innovation Foundation, Daegu, Korea
- Mucosal Immunology Lab., Department of Biological Sciences, Pusan National University, Busan, Korea
| | - Ju Bin Yoon
- Department of Convergence Study on the Ocean Science and Technology, Korea Maritime & Ocean University, Busan, Korea
- Lab. of Marine Microbiology, Division of Convergence on Marine Science, Korea Maritime & Ocean University, Busan, Korea
| | - Jun Hyeok Yang
- Lab. of Marine Microbiology, Division of Convergence on Marine Science, Korea Maritime & Ocean University, Busan, Korea
- Department of Marine Bioscience and Environment, Korea Maritime & Ocean University, Busan, Korea
| | - Jin-Young Yang
- Mucosal Immunology Lab., Department of Biological Sciences, Pusan National University, Busan, Korea
| | - Ki Hwan Moon
- Department of Convergence Study on the Ocean Science and Technology, Korea Maritime & Ocean University, Busan, Korea
- Lab. of Marine Microbiology, Division of Convergence on Marine Science, Korea Maritime & Ocean University, Busan, Korea
- Department of Marine Bioscience and Environment, Korea Maritime & Ocean University, Busan, Korea
| | - Ho Young Kang
- Department of Microbiology, Pusan National University, Busan, Korea
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50
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Mariano G, Faba-Rodriguez R, Bui S, Zhao W, Ross J, Tzokov SB, Bergeron JRC. Oligomerization of the FliF Domains Suggests a Coordinated Assembly of the Bacterial Flagellum MS Ring. Front Microbiol 2022; 12:781960. [PMID: 35087486 PMCID: PMC8786727 DOI: 10.3389/fmicb.2021.781960] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 12/08/2021] [Indexed: 12/30/2022] Open
Abstract
The bacterial flagellum is a complex, self-assembling macromolecular machine that powers bacterial motility. It plays diverse roles in bacterial virulence, including aiding in colonization and dissemination during infection. The flagellum consists of a filamentous structure protruding from the cell, and of the basal body, a large assembly that spans the cell envelope. The basal body is comprised of over 20 different proteins forming several concentric ring structures, termed the M- S- L- P- and C-rings, respectively. In particular, the MS rings are formed by a single protein FliF, which consists of two trans-membrane helices anchoring it to the inner membrane and surrounding a large periplasmic domain. Assembly of the MS ring, through oligomerization of FliF, is one of the first steps of basal body assembly. Previous computational analysis had shown that the periplasmic region of FliF consists of three structurally similar domains, termed Ring-Building Motif (RBM)1, RBM2, and RBM3. The structure of the MS-ring has been reported recently, and unexpectedly shown that these three domains adopt different symmetries, with RBM3 having a 34-mer stoichiometry, while RBM2 adopts two distinct positions in the complex, including a 23-mer ring. This observation raises some important question on the assembly of the MS ring, and the formation of this symmetry mismatch within a single protein. In this study, we analyze the oligomerization of the individual RBM domains in isolation, in the Salmonella enterica serovar Typhimurium FliF ortholog. We demonstrate that the periplasmic domain of FliF assembles into the MS ring, in the absence of the trans-membrane helices. We also report that the RBM2 and RBM3 domains oligomerize into ring structures, but not RBM1. Intriguingly, we observe that a construct encompassing RBM1 and RBM2 is monomeric, suggesting that RBM1 interacts with RBM2, and inhibits its oligomerization. However, this inhibition is lifted by the addition of RBM3. Collectively, this data suggest a mechanism for the controlled assembly of the MS ring.
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Affiliation(s)
- Giuseppina Mariano
- Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Raquel Faba-Rodriguez
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Soi Bui
- Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - Weilong Zhao
- Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom
| | - James Ross
- Department of Biochemistry, University of British Columbia, Vancouver, BC, Canada
| | - Svetomir B Tzokov
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
| | - Julien R C Bergeron
- Randall Division of Cell and Molecular Biophysics, King's College London, London, United Kingdom.,Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, United Kingdom
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