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Ellison TJ, Ellison CK. DNA binding is rate-limiting for natural transformation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.06.597730. [PMID: 38895488 PMCID: PMC11185590 DOI: 10.1101/2024.06.06.597730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Bacteria take up environmental DNA using dynamic appendages called type IV pili (T4P) to elicit horizontal gene transfer in a process called natural transformation. Natural transformation is widespread amongst bacteria yet determining how different factors universally contribute to or limit this process across species has remained challenging. Here we show that Acinetobacter baylyi, the most naturally transformable species, is highly transformable due to its ability to robustly bind nonspecific DNA via a dedicated orphan minor pilin, FimT. We show that, compared to its homologues, A. baylyi FimT contains multiple positively charged residues that additively promote DNA binding efficiency. Expression of A. baylyi FimT in a closely related Acinetobacter pathogen is sufficient to substantially improve its capacity for natural transformation, demonstrating that T4P-DNA binding is a rate-limiting step in this process. These results demonstrate the importance of T4P-DNA binding efficiency in driving natural transformation, establishing a key factor limiting horizontal gene transfer.
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2
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Whitfield GB, Brun YV. The type IVc pilus: just a Tad different. Curr Opin Microbiol 2024; 79:102468. [PMID: 38579360 DOI: 10.1016/j.mib.2024.102468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/12/2024] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Bacteria utilize type IV pili (T4P) to interact with their environment, where they facilitate processes including motility, adherence, and DNA uptake. T4P require multisubunit, membrane-spanning nanomachines for assembly. The tight adherence (Tad) pili are an Archaea-derived T4P subgroup whose machinery exhibits significant mechanistic and architectural differences from bacterial type IVa and IVb pili. Most Tad biosynthetic genes are encoded in a single locus that is widespread in bacteria due to facile acquisition via horizontal gene transfer. These loci experience extensive structural rearrangements, including the acquisition of novel regulatory or biosynthetic genes, which fine-tune their function. This has permitted their integration into many different bacterial lifestyles, including the Caulobacter crescentus cell cycle, Myxococcus xanthus predation, and numerous plant and mammalian pathogens and symbionts.
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Affiliation(s)
- Gregory B Whitfield
- Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, Québec H3C 3J7, Canada.
| | - Yves V Brun
- Département de Microbiologie, Infectiologie, et Immunologie, Université de Montréal, C.P. 6128, succ. Centre-ville, Montréal, Québec H3C 3J7, Canada
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3
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Chen X, Yang G, Quan X, Zhu S, Qin B, Shou D, Zhuang L. Significance of a minor pilin PilV in biofilm cohesion of Geobacter sulfurreducens. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 927:172242. [PMID: 38582122 DOI: 10.1016/j.scitotenv.2024.172242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/03/2024] [Accepted: 04/03/2024] [Indexed: 04/08/2024]
Abstract
Bacterial adhesion plays a vital role in forming and shaping the structure of electroactive biofilms that are essential for the performance of bioelectrochemical systems (BESs). Type IV pili are known to mediate cell adhesion in many Gram-negative bacteria, but the mechanism of pili-mediated cell adhesion of Geobacter species on anode surface remains unclear. Herein, a minor pilin PilV2 was found to be essential for cell adhesion ability of Geobacter sulfurreducens since the lack of pilV2 gene depressed the cell adhesion capability by 81.2% in microplate and the anodic biofilm density by 23.1 % at -0.1 V and 37.7 % at -0.3 V in BESs. The less cohesiveness of mutant biofilms increased the charge transfer resistance and biofilm resistance, which correspondingly lowered current generation of the pilV2-deficient strain by up to 63.2 % compared with that of the wild-type strain in BESs. The deletion of pilV2 posed an insignificant effect on the production of extracellular polysaccharides, pili, extracellular cytochromes and electron shuttles that are involved in biofilm formation or extracellular electron transfer (EET) process. This study demonstrated the significance of pilV2 gene in cell adhesion and biofilm formation of G. sulfurreducens, as well as the importance of pili-mediated adhesion for EET of electroactive biofilm.
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Affiliation(s)
- Xiaochun Chen
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Guiqin Yang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Xiaoyun Quan
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Siyue Zhu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Baoli Qin
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Danyang Shou
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China
| | - Li Zhuang
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
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Chen YYM, Yang YC, Shieh HR, Lin YJ, Ke WJ, Chiu CH. Functional Analysis of the Major Pilin Proteins of Type IV Pili in Streptococcus sanguinis CGMH010. Int J Mol Sci 2024; 25:5402. [PMID: 38791440 PMCID: PMC11121087 DOI: 10.3390/ijms25105402] [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: 03/29/2024] [Revised: 05/02/2024] [Accepted: 05/03/2024] [Indexed: 05/26/2024] Open
Abstract
The pil gene cluster for Type IV pilus (Tfp) biosynthesis is commonly present and highly conserved in Streptococcus sanguinis. Nevertheless, Tfp-mediated twitching motility is less common among strains, and the factors determining twitching activity are not fully understood. Here, we analyzed the functions of three major pilin proteins (PilA1, PilA2, and PilA3) in the assembly and activity of Tfp in motile S. sanguinis CGMH010. Using various recombinant pilA deletion strains, we found that Tfp composed of different PilA proteins varied morphologically and functionally. Among the three PilA proteins, PilA1 was most critical in the assembly of twitching-active Tfp, and recombinant strains expressing motility generated more structured biofilms under constant shearing forces compared to the non-motile recombinant strains. Although PilA1 and PilA3 shared 94% identity, PilA3 could not compensate for the loss of PilA1, suggesting that the nature of PilA proteins plays an essential role in twitching activity. The single deletion of individual pilA genes had little effect on the invasion of host endothelia by S. sanguinis CGMH010. In contrast, the deletion of all three pilA genes or pilT, encoding the retraction ATPase, abolished Tfp-mediated invasion. Tfp- and PilT-dependent invasion were also detected in the non-motile S. sanguinis SK36, and thus, the retraction of Tfp, but not active twitching, was found to be essential for invasion.
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Affiliation(s)
- Yi-Ywan M. Chen
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-R.S.); (Y.-J.L.); (W.-J.K.)
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Linkou 333, Taiwan;
| | - Yuan-Chen Yang
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Hui-Ru Shieh
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-R.S.); (Y.-J.L.); (W.-J.K.)
| | - Yu-Juan Lin
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-R.S.); (Y.-J.L.); (W.-J.K.)
| | - Wan-Ju Ke
- Department of Microbiology and Immunology, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan; (H.-R.S.); (Y.-J.L.); (W.-J.K.)
| | - Cheng-Hsun Chiu
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Linkou 333, Taiwan;
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5
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Bhattacharyya A, Banerjee G, Chattopadhyay P. Probable Role of Type IV Pili of Aeromonas hydrophila in Human Pathogenicity. Pathogens 2024; 13:365. [PMID: 38787217 PMCID: PMC11124393 DOI: 10.3390/pathogens13050365] [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: 02/18/2024] [Revised: 04/15/2024] [Accepted: 04/24/2024] [Indexed: 05/25/2024] Open
Abstract
BACKGROUND Aeromonas hydrophila is a widely recognized broad-spectrum pathogen that primarily targets the gastrointestinal tract. Type IV pili (T4P) are proteinaceous nano-machines located on the bacterial cell surface, playing a crucial role in host colonization and infection. Regrettably, the T4P systems of A. hydrophila remain largely underexplored. METHODS A. hydrophila genomes with complete genome assembly and annotation reports up to 31 March 2023, were obtained from the NCBI Genome database or KEGG genome database, followed by a global search for T4P secretion system genes. Protein sequences of these manually curetted genes were used as secondary quarry for Synteny analysis. Protein-protein interaction analysis was performed by string analysis and in silico study of genomic islands. RESULTS We identified 27 orthologs of type IV pili (T4P) nano-machine components in A. hydrophila. These orthologs are primarily distributed across three operons: pilABCD, pilMNOPQ, and pilVWXY. While the first two operons are commonly found in all experimental genomes, the presence of the pilVWXY operon, coding for 11 orthologs, is reported here for the first time in A. hydrophila. Notably, the complete pilVWXY operon is absent in nonvirulent strains. A genomic islands study between a nonvirulent and hypervirulent strain also confirms absence of most of the genes coded by pilVWXY in nonvirulent strain. Interestingly, among the 51 experimental genomes analyzed, the pilVWXY operon was completely absent in 10 strains, most of which are categorized as nonvirulent; Conclusions: The distribution of two major type IV pili (T4P) nano-machines, PilABCDMNOPQ and PilVWXY, is reported here for the first time in A. hydrophila. Additionally, this study suggests a potential role for the PilVWXY nano-machine in establishing human disease.
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Affiliation(s)
- Agradip Bhattacharyya
- Raja Rammohun Roy Mahavidyalaya, Radhanagar, Nangulpara, Hooghly, West Bengal 712406, India;
| | - Goutam Banerjee
- Department of Food Science and Human Nutrition, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Hernández-Sánchez A, Páez-Pérez ED, Alfaro-Saldaña E, Olivares-Illana V, García-Meza JV. Understanding a Core Pilin of the Type IVa Pili of Acidithiobacillus thiooxidans, PilV. J Microbiol Biotechnol 2024; 34:527-537. [PMID: 38346803 PMCID: PMC11016768 DOI: 10.4014/jmb.2310.10033] [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: 10/25/2023] [Revised: 12/22/2023] [Accepted: 12/29/2023] [Indexed: 04/17/2024]
Abstract
Pilins are protein subunits of pili. The pilins of type IV pili (T4P) in pathogenic bacteria are well characterized, but anything is known about the T4P proteins in acidophilic chemolithoautotrophic microorganisms such as the genus Acidithiobacillus. The interest in T4P of A. thiooxidans is because of their possible role in cell recruitment and bacterial aggregation on the surface of minerals during biooxidation of sulfide minerals. In this study we present a successful ad hoc methodology for the heterologous expression and purification of extracellular proteins such as the minor pilin PilV of the T4P of A. thiooxidans, a pilin exposed to extreme conditions of acidity and high oxidation-reduction potentials, and that interact with metal sulfides in an environment rich in dissolved minerals. Once obtained, the model structure of A. thiooxidans PilV revealed the core basic architecture of T4P pilins. Because of the acidophilic condition, we carried out in silico characterization of the protonation status of acidic and basic residues of PilV in order to calculate the ionization state at specific pH values and evaluated their pH stability. Further biophysical characterization was done using UV-visible and fluorescence spectroscopy and the results showed that PilV remains soluble and stable even after exposure to significant changes of pH. PilV has a unique amino acid composition that exhibits acid stability, with significant biotechnology implications such as biooxidation of sulfide minerals. The biophysics profiles of PilV open new paradigms about resilient proteins and stimulate the study of other pilins from extremophiles.
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Affiliation(s)
- Araceli Hernández-Sánchez
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| | - Edgar D. Páez-Pérez
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| | - Elvia Alfaro-Saldaña
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
| | - Vanesa Olivares-Illana
- Laboratorio de Interacciones Biomoleculares y Cáncer. Instituto de Física, Universidad Autónoma de San Luis Potosí, Av. Parque Chapultepec 1570, Privadas del Pedregal, San Luis Potosí, 78210, SLP, México
| | - J. Viridiana García-Meza
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, San Luis Potosí, 78210, SLP, México
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7
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Zuke JD, Burton BM. From isotopically labeled DNA to fluorescently labeled dynamic pili: building a mechanistic model of DNA transport to the cytoplasmic membrane. Microbiol Mol Biol Rev 2024; 88:e0012523. [PMID: 38466096 PMCID: PMC10966944 DOI: 10.1128/mmbr.00125-23] [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] [Indexed: 03/12/2024] Open
Abstract
SUMMARYNatural competence, the physiological state wherein bacteria produce proteins that mediate extracellular DNA transport into the cytosol and the subsequent recombination of DNA into the genome, is conserved across the bacterial domain. DNA must successfully translocate across formidable permeability barriers during import, including the cell membrane(s) and the cell wall, that are normally impermeable to large DNA polymers. This review will examine the mechanisms underlying DNA transport from the extracellular space to the cytoplasmic membrane. First, the challenges inherent to DNA movement through the cell periphery will be discussed to provide context for DNA transport during natural competence. The following sections will trace the development of a comprehensive model for DNA translocation to the cytoplasmic membrane, highlighting the crucial studies performed over the last century that have contributed to building contemporary DNA import models. Finally, this review will conclude by reflecting on what is still unknown about the process and the possible solutions to overcome these limitations.
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Affiliation(s)
- Jason D. Zuke
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin–Madison, Madison, Wisconsin, USA
| | - Briana M. Burton
- Department of Bacteriology, University of Wisconsin–Madison, Madison, Wisconsin, USA
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8
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Little JI, Singh PK, Zhao J, Dunn S, Matz H, Donnenberg MS. Type IV pili of Enterobacteriaceae species. EcoSal Plus 2024:eesp00032023. [PMID: 38294234 DOI: 10.1128/ecosalplus.esp-0003-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 12/01/2023] [Indexed: 02/01/2024]
Abstract
Type IV pili (T4Ps) are surface filaments widely distributed among bacteria and archaea. T4Ps are involved in many cellular functions and contribute to virulence in some species of bacteria. Due to the diversity of T4Ps, different properties have been observed for homologous proteins that make up T4Ps in various organisms. In this review, we highlight the essential components of T4Ps, their functions, and similarities to related systems. We emphasize the unique T4Ps of enteric pathogens within the Enterobacteriaceae family, which includes pathogenic strains of Escherichia coli and Salmonella. These include the bundle-forming pilus (BFP) of enteropathogenic E. coli (EPEC), longus (Lng) and colonization factor III (CFA/III) of enterotoxigenic E. coli (ETEC), T4P of Salmonella enterica serovar Typhi, Colonization Factor Citrobacter (CFC) of Citrobacter rodentium, T4P of Yersinia pseudotuberculosis, a ubiquitous T4P that was characterized in enterohemorrhagic E. coli (EHEC), and the R64 plasmid thin pilus. Finally, we highlight areas for further study.
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Affiliation(s)
- Janay I Little
- School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Pradip K Singh
- School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Jinlei Zhao
- School of Medicine, Virginia Commonwealth University, Richmond, Virginia, USA
| | - Shakeera Dunn
- Internal Medicine Residency, Bayhealth Medical Center, Dover, Delaware, USA
| | - Hanover Matz
- Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
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9
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Mi Y, He Y, Mi J, Huang Y, Fan H, Song L, An X, Xu S, Li M, Tong Y. Genetic and Phenotypic Analysis of Phage-Resistant Mutant Fitness Triggered by Phage-Host Interactions. Int J Mol Sci 2023; 24:15594. [PMID: 37958578 PMCID: PMC10648725 DOI: 10.3390/ijms242115594] [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: 09/28/2023] [Revised: 10/16/2023] [Accepted: 10/19/2023] [Indexed: 11/15/2023] Open
Abstract
The emergence of phage-resistant bacterial strains is one of the biggest challenges for phage therapy. However, the emerging phage-resistant bacteria are often accompanied by adaptive trade-offs, which supports a therapeutic strategy called "phage steering". The key to phage steering is to guide the bacterial population toward an evolutionary direction that is favorable for treatment. Thus, it is important to systematically investigate the impacts of phages targeting different bacterial receptors on the fitness of the bacterial population. Herein, we employed 20 different phages to impose strong evolutionary pressure on the host Pseudomonas aeruginosa PAO1 and examined the genetic and phenotypic responses of their phage-resistant mutants. Among these strains with impaired adsorptions, four types of mutations associated with bacterial receptors were identified, namely, lipopolysaccharides (LPSs), type IV pili (T4Ps), outer membrane proteins (OMPs), and exopolysaccharides (EPSs). PAO1, responding to LPS- and EPS-dependent phage infections, mostly showed significant growth impairment and virulence attenuation. Most mutants with T4P-related mutations exhibited a significant decrease in motility and biofilm formation ability, while the mutants with OMP-related mutations required the lowest fitness cost out of the bacterial populations. Apart from fitness costs, PAO1 strains might lose their resistance to antibiotics when counteracting with phages, such as the presence of large-fragment mutants in this study, which may inspire the usage of phage-antibiotic combination strategies. This work provides methods that leverage the merits of phage resistance relative to obtaining therapeutically beneficial outcomes with respect to phage-steering strategies.
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Affiliation(s)
- Yanze Mi
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Yile He
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Jinhui Mi
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Yunfei Huang
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Huahao Fan
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Lihua Song
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Xiaoping An
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Shan Xu
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Mengzhe Li
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
| | - Yigang Tong
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China; (Y.M.); (Y.H.); (J.M.); (Y.H.); (H.F.); (L.S.); (X.A.); (S.X.)
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering (BAIC-SM), Beijing University of Chemical Technology, Beijing 100029, China
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10
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Páez-Pérez ED, Hernández-Sánchez A, Alfaro-Saldaña E, García-Meza JV. Disorder and amino acid composition in proteins: their potential role in the adaptation of extracellular pilins to the acidic media, where Acidithiobacillus thiooxidans grows. Extremophiles 2023; 27:31. [PMID: 37848738 DOI: 10.1007/s00792-023-01317-z] [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: 03/08/2023] [Accepted: 09/26/2023] [Indexed: 10/19/2023]
Abstract
There are few biophysical studies or structural characterizations of the type IV pilin system of extremophile bacteria, such as the acidophilic Acidithiobacillus thiooxidans. We set out to analyze their pili-comprising proteins, pilins, because these extracellular proteins are in constant interaction with protons of the acidic medium in which At. thiooxidans grows. We used the web server Operon Mapper to analyze and identify the cluster codified by the minor pilin of At. thiooxidans. In addition, we carried an in-silico characterization of such pilins using the VL-XT algorithm of PONDR® server. Our results showed that structural disorder prevails more in pilins of At. thiooxidans than in non-acidophilic bacteria. Further computational characterization showed that the pilins of At. thiooxidans are significantly enriched in hydroxy (serine and threonine) and amide (glutamine and asparagine) residues, and significantly reduced in charged residues (aspartic acid, glutamic acid, arginine and lysine). Similar results were obtained when comparing pilins from other Acidithiobacillus and other acidophilic bacteria from another genus versus neutrophilic bacteria, suggesting that these properties are intrinsic to pilins from acidic environments, most likely by maintaining solubility and stability in harsh conditions. These results give guidelines for the application of extracellular proteins of acidophiles in protein engineering.
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Affiliation(s)
- Edgar D Páez-Pérez
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, 78210, San Luis Potosí, SLP, Mexico.
| | - Araceli Hernández-Sánchez
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, 78210, San Luis Potosí, SLP, Mexico.
| | - Elvia Alfaro-Saldaña
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, 78210, San Luis Potosí, SLP, Mexico
| | - J Viridiana García-Meza
- Geomicrobiología, Metalurgia, Universidad Autónoma de San Luis Potosí, Sierra Leona 550, 78210, San Luis Potosí, SLP, Mexico
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11
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Wang L, Wong YC, Correira JM, Wancura M, Geiger CJ, Webster SS, Touhami A, Butler BJ, O'Toole GA, Langford RM, Brown KA, Dortdivanlioglu B, Webb L, Cosgriff-Hernandez E, Gordon VD. The accumulation and growth of Pseudomonas aeruginosa on surfaces is modulated by surface mechanics via cyclic-di-GMP signaling. NPJ Biofilms Microbiomes 2023; 9:78. [PMID: 37816780 PMCID: PMC10564899 DOI: 10.1038/s41522-023-00436-x] [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: 09/12/2023] [Indexed: 10/12/2023] Open
Abstract
Attachment of bacteria onto a surface, consequent signaling, and accumulation and growth of the surface-bound bacterial population are key initial steps in the formation of pathogenic biofilms. While recent reports have hinted that surface mechanics may affect the accumulation of bacteria on that surface, the processes that underlie bacterial perception of surface mechanics and modulation of accumulation in response to surface mechanics remain largely unknown. We use thin and thick hydrogels coated on glass to create composite materials with different mechanics (higher elasticity for thin composites; lower elasticity for thick composites) but with the same surface adhesivity and chemistry. The mechanical cue stemming from surface mechanics is elucidated using experiments with the opportunistic human pathogen Pseudomonas aeruginosa combined with finite-element modeling. Adhesion to thin composites results in greater changes in mechanical stress and strain in the bacterial envelope than does adhesion to thick composites with identical surface chemistry. Using quantitative microscopy, we find that adhesion to thin composites also results in higher cyclic-di-GMP levels, which in turn result in lower motility and less detachment, and thus greater accumulation of bacteria on the surface than does adhesion to thick composites. Mechanics-dependent c-di-GMP production is mediated by the cell-surface-exposed protein PilY1. The biofilm lag phase, which is longer for bacterial populations on thin composites than on thick composites, is also mediated by PilY1. This study shows clear evidence that bacteria actively regulate differential accumulation on surfaces of different stiffnesses via perceiving varied mechanical stress and strain upon surface engagement.
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Affiliation(s)
- Liyun Wang
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Yu-Chern Wong
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, 78712, USA
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Joshua M Correira
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Megan Wancura
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Chris J Geiger
- Geisel School of Medicine at Dartmouth, Hanover, NH, 03755, USA
| | | | - Ahmed Touhami
- Department of Physics and Astronomy University of Texas Rio Grande Valley, One West University Blvd, Brownsville, TX, 78520, USA
| | - Benjamin J Butler
- Surfaces, Microstructure and Fracture Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | | | - Richard M Langford
- Surfaces, Microstructure and Fracture Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
| | - Katherine A Brown
- Surfaces, Microstructure and Fracture Group, Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK
- Oden Institute for Computational Engineering & Sciences, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Berkin Dortdivanlioglu
- Department of Civil, Architectural, and Environmental Engineering, The University of Texas at Austin, Austin, TX, 78712, USA
| | - Lauren Webb
- Department of Chemistry, The University of Texas at Austin, Austin, TX, 78712, USA
| | | | - Vernita D Gordon
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, 78712, USA.
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, TX, 78712, USA.
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX, 78712, USA.
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12
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Zuke JD, Erickson R, Hummels KR, Burton BM. Visualizing dynamic competence pili and DNA capture throughout the long axis of Bacillus subtilis. J Bacteriol 2023; 205:e0015623. [PMID: 37695859 PMCID: PMC10521363 DOI: 10.1128/jb.00156-23] [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: 05/31/2023] [Accepted: 06/05/2023] [Indexed: 09/13/2023] Open
Abstract
The first step in the process of bacterial natural transformation is DNA capture. Although long hypothesized based on genetics and functional experiments, the pilus structure responsible for initial DNA binding had not yet been visualized for Bacillus subtilis. Here, we visualize functional competence pili in Bacillus subtilis using fluorophore-conjugated maleimide labeling in conjunction with epifluorescence microscopy. In strains that produce pilin monomers within tenfold of wild-type levels, the median length of detectable pili is 300 nm. These pili are retractile and associate with DNA. The analysis of pilus distribution at the cell surface reveals that they are predominantly located along the long axis of the cell. The distribution is consistent with localization of proteins associated with subsequent transformation steps, DNA binding, and DNA translocation in the cytosol. These data suggest a distributed model for B. subtilis transformation machinery, in which initial steps of DNA capture occur throughout the long axis of the cell and subsequent steps may also occur away from the cell poles. IMPORTANCE This work provides novel visual evidence for DNA translocation across the cell wall during Bacillus subtilis natural competence, an essential step in the natural transformation process. Our data demonstrate the existence of natural competence-associated retractile pili that can bind exogenous DNA. Furthermore, we show that pilus biogenesis occurs throughout the cell long axis. These data strongly support DNA translocation occurring all along the lateral cell wall during natural competence, wherein pili are produced, bind to free DNA in the extracellular space, and finally retract to pull the bound DNA through the gap in the cell wall created during pilus biogenesis.
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Affiliation(s)
- Jason D. Zuke
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Rachel Erickson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Katherine R. Hummels
- Department of Microbiology and Immunology, Harvard Medical School, Boston, MA, USA
| | - Briana M. Burton
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA
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13
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Ghosh M, Raghav S, Ghosh P, Maity S, Mohela K, Jain D. Structural analysis of novel drug targets for mitigation of Pseudomonas aeruginosa biofilms. FEMS Microbiol Rev 2023; 47:fuad054. [PMID: 37771093 DOI: 10.1093/femsre/fuad054] [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: 05/30/2023] [Revised: 09/20/2023] [Accepted: 09/27/2023] [Indexed: 09/30/2023] Open
Abstract
Pseudomonas aeruginosa is an opportunistic human pathogen responsible for acute and chronic, hard to treat infections. Persistence of P. aeruginosa is due to its ability to develop into biofilms, which are sessile bacterial communities adhered to substratum and encapsulated in layers of self-produced exopolysaccharides. These biofilms provide enhanced protection from the host immune system and resilience towards antibiotics, which poses a challenge for treatment. Various strategies have been expended for combating biofilms, which involve inhibiting biofilm formation or promoting their dispersal. The current remediation approaches offer some hope for clinical usage, however, treatment and eradication of preformed biofilms is still a challenge. Thus, identifying novel targets and understanding the detailed mechanism of biofilm regulation becomes imperative. Structure-based drug discovery (SBDD) provides a powerful tool that exploits the knowledge of atomic resolution details of the targets to search for high affinity ligands. This review describes the available structural information on the putative target protein structures that can be utilized for high throughput in silico drug discovery against P. aeruginosa biofilms. Integrating available structural information on the target proteins in readily accessible format will accelerate the process of drug discovery.
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Affiliation(s)
- Moumita Ghosh
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Shikha Raghav
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Puja Ghosh
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Swagatam Maity
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Kavery Mohela
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
| | - Deepti Jain
- Transcription Regulation Lab, Regional Centre for Biotechnology, NCR Biotech Science Cluster, 3rd Milestone, Faridabad-Gurugram Expressway, Faridabad, Haryana-121001, India
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14
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Yang P, Qu C, Yuan M, Xi B, Jia X, Zhang B, Zhang L. Genetic Basis and Expression Pattern Indicate the Biocontrol Potential and Soil Adaption of Lysobacter capsici CK09. Microorganisms 2023; 11:1768. [PMID: 37512940 PMCID: PMC10384520 DOI: 10.3390/microorganisms11071768] [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: 06/06/2023] [Revised: 06/27/2023] [Accepted: 06/28/2023] [Indexed: 07/30/2023] Open
Abstract
Lysobacter species have attracted increasing attention in recent years due to their capacities to produce diverse secondary metabolites against phytopathogens. In this research, we analyzed the genomic and transcriptomic patterns of Lysobacter capsici CK09. Our data showed that L. capsici CK09 harbored various contact-independent biocontrol traits, such as fungal cell wall lytic enzymes and HSAF/WAP-8294A2 biosynthesis, as well as several contact-dependent machineries, including type 2/4/6 secretion systems. Additionally, a variety of hydrolytic enzymes, particularly extracellular enzymes, were found in the L. capsici CK09 genome and predicted to improve its adaption in soil. Furthermore, several systems, including type 4 pili, type 3 secretion system and polysaccharide biosynthesis, can provide a selective advantage to L. capsici CK09, enabling the species to live on the surface in soil. The expression of these genes was then confirmed via transcriptomic analysis, indicating the activities of these genes. Collectively, our research provides a comprehensive understanding of the biocontrol potential and soil adaption of L. capsici CK09 and implies the potential of this strain for application in the future.
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Affiliation(s)
- Pu Yang
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Chaofan Qu
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Miaomiao Yuan
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Bo Xi
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Xiu Jia
- Institute of Biodiversity, Faculty of Biological Sciences, Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, 07745 Jena, Germany
| | - Ben Zhang
- School of Life Science, Shanxi University, Taiyuan 030006, China
| | - Lizhen Zhang
- School of Life Science, Shanxi University, Taiyuan 030006, China
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15
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Iruegas R, Pfefferle K, Göttig S, Averhoff B, Ebersberger I. Feature architecture aware phylogenetic profiling indicates a functional diversification of type IVa pili in the nosocomial pathogen Acinetobacter baumannii. PLoS Genet 2023; 19:e1010646. [PMID: 37498819 PMCID: PMC10374093 DOI: 10.1371/journal.pgen.1010646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 06/06/2023] [Indexed: 07/29/2023] Open
Abstract
The Gram-negative bacterial pathogen Acinetobacter baumannii is a major cause of hospital-acquired opportunistic infections. The increasing spread of pan-drug resistant strains makes A. baumannii top-ranking among the ESKAPE pathogens for which novel routes of treatment are urgently needed. Comparative genomics approaches have successfully identified genetic changes coinciding with the emergence of pathogenicity in Acinetobacter. Genes that are prevalent both in pathogenic and a-pathogenic Acinetobacter species were not considered ignoring that virulence factors may emerge by the modification of evolutionarily old and widespread proteins. Here, we increased the resolution of comparative genomics analyses to also include lineage-specific changes in protein feature architectures. Using type IVa pili (T4aP) as an example, we show that three pilus components, among them the pilus tip adhesin ComC, vary in their Pfam domain annotation within the genus Acinetobacter. In most pathogenic Acinetobacter isolates, ComC displays a von Willebrand Factor type A domain harboring a finger-like protrusion, and we provide experimental evidence that this finger conveys virulence-related functions in A. baumannii. All three genes are part of an evolutionary cassette, which has been replaced at least twice during A. baumannii diversification. The resulting strain-specific differences in T4aP layout suggests differences in the way how individual strains interact with their host. Our study underpins the hypothesis that A. baumannii uses T4aP for host infection as it was shown previously for other pathogens. It also indicates that many more functional complexes may exist whose precise functions have been adjusted by modifying individual components on the domain level.
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Affiliation(s)
- Ruben Iruegas
- Applied Bioinformatics Group, Inst of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Katharina Pfefferle
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Stephan Göttig
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe University, Frankfurt, Germany
| | - Beate Averhoff
- Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Ingo Ebersberger
- Applied Bioinformatics Group, Inst of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
- Senckenberg Biodiversity and Climate Research Centre (S-BIK-F), Frankfurt am Main, Germany
- LOEWE Centre for Translational Biodiversity Genomics (TBG), Frankfurt am Main, Germany
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16
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Bianco MI, Ponso MA, Garita-Cambronero J, Conforte VP, Galván TE, Dunger G, Morales GM, Vojnov AA, Romero AM, Cubero J, Yaryura PM. Genomic and phenotypic insight into Xanthomonas vesicatoria strains with different aggressiveness on tomato. Front Microbiol 2023; 14:1185368. [PMID: 37440880 PMCID: PMC10333488 DOI: 10.3389/fmicb.2023.1185368] [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: 03/13/2023] [Accepted: 06/09/2023] [Indexed: 07/15/2023] Open
Abstract
Xanthomonas vesicatoria is one of the causal agents of bacterial spot, a disease that seriously affects the production of tomato (Solanum lycopersicum) and pepper (Capsicum annum) worldwide. In Argentina, bacterial spot is found in all tomato producing areas, with X. vesicatoria being one of the main species detected in the fields. Previously, we isolated three X. vesicatoria strains BNM 208, BNM 214, and BNM 216 from tomato plants with bacterial spot, and found they differed in their ability to form biofilm and in their degree of aggressiveness. Here, the likely causes of those differences were explored through genotypic and phenotypic studies. The genomes of the three strains were sequenced and assembled, and then compared with each other and also with 12 other publicly available X. vesicatoria genomes. Phenotypic characteristics (mainly linked to biofilm formation and virulence) were studied in vitro. Our results show that the differences observed earlier between BNM 208, BNM 214, and BNM 216 may be related to the structural characteristics of the xanthan gum produced by each strain, their repertoire of type III effectors (T3Es), the presence of certain genes associated with c-di-GMP metabolism and type IV pili (T4P). These findings on the pathogenicity mechanisms of X. vesicatoria could be useful for developing bacterial spot control strategies aimed at interfering with the infection processes.
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Affiliation(s)
- María Isabel Bianco
- Instituto de Ciencia y Tecnología Dr. César Milstein – Fundación Pablo Cassará – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Instituto de Investigación en Medicina y Ciencias de la Salud, Facultad de Medicina, Universidad del Salvador, Buenos Aires, Argentina
| | - María Agustina Ponso
- Instituto Multidisciplinario de Investigación y Transferencia Agroalimentario y Biotecnológica (IMITAB, UNVM-CONICET), Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas, Universidad Nacional de Villa María, Villa María, Argentina
| | | | - Valeria Paola Conforte
- Instituto de Ciencia y Tecnología Dr. César Milstein – Fundación Pablo Cassará – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Instituto de Investigación en Medicina y Ciencias de la Salud, Facultad de Medicina, Universidad del Salvador, Buenos Aires, Argentina
| | - Tadeo E. Galván
- Instituto de Ciencia y Tecnología Dr. César Milstein – Fundación Pablo Cassará – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Germán Dunger
- Facultad de Ciencias Agrarias, Instituto de Ciencias Agropecuarias del Litoral, CONICET, Universidad Nacional del Litoral, Esperanza, Argentina
| | - Gustavo M. Morales
- Departamento de Química, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados, Universidad Nacional de Rio Cuarto – CONICET, Rio Cuarto, Argentina
| | - Adrián Alberto Vojnov
- Instituto de Ciencia y Tecnología Dr. César Milstein – Fundación Pablo Cassará – Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Instituto de Investigación en Medicina y Ciencias de la Salud, Facultad de Medicina, Universidad del Salvador, Buenos Aires, Argentina
| | - Ana María Romero
- Cátedra de Fitopatología, Departamento de Producción Vegetal, Facultad de Agronomía, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Jaime Cubero
- Laboratorio de Bacteriología, Departamento de Protección Vegetal, Instituto Nacional de Investigación y Tecnología Agraria/Consejo Superior de Investigaciones Científicas (INIA/CSIC), Madrid, Spain
| | - Pablo Marcelo Yaryura
- Instituto Multidisciplinario de Investigación y Transferencia Agroalimentario y Biotecnológica (IMITAB, UNVM-CONICET), Instituto Académico Pedagógico de Ciencias Básicas y Aplicadas, Universidad Nacional de Villa María, Villa María, Argentina
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17
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Zuke JD, Erickson R, Hummels KR, Burton BM. Visualizing dynamic competence pili and DNA capture throughout the long axis of Bacillus subtilis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.26.542325. [PMID: 37292776 PMCID: PMC10246001 DOI: 10.1101/2023.05.26.542325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The first step in the process of bacterial natural transformation is DNA capture. Although long-hypothesized based on genetics and functional experiments, the pilus structure responsible for initial DNA-binding had not yet been visualized for Bacillus subtilis. Here, we visualize functional competence pili in Bacillus subtilis using fluorophore-conjugated maleimide labeling in conjunction with epifluorescence microscopy. In strains that produce pilin monomers within ten-fold of wild type levels, the median length of detectable pili is 300nm. These pili are retractile and associate with DNA. Analysis of pilus distribution at the cell surface reveals that they are predominantly located along the long axis of the cell. The distribution is consistent with localization of proteins associated with subsequent transformation steps, DNA-binding and DNA translocation in the cytosol. These data suggest a distributed model for B. subtilis transformation machinery, in which initial steps of DNA capture occur throughout the long axis of the cell and subsequent steps may also occur away from the cell poles.
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Affiliation(s)
- Jason D. Zuke
- Department of Bacteriology, University of Wisconsin - Madison
- Microbiology Doctoral Training Program, University of Wisconsin - Madison
| | - Rachel Erickson
- Department of Bacteriology, University of Wisconsin - Madison
| | - Katherine R. Hummels
- Current address: Department of Microbiology and Immunology, Harvard Medical School
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18
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Nguyen M, Wu TH, Danielson K, Khan N, Zhang J, Craig L. Mechanism of secretion of TcpF by the Vibrio cholerae toxin-coregulated pilus. Proc Natl Acad Sci U S A 2023; 120:e2212664120. [PMID: 37040409 PMCID: PMC10120004 DOI: 10.1073/pnas.2212664120] [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: 07/25/2022] [Accepted: 02/28/2023] [Indexed: 04/12/2023] Open
Abstract
Many bacteria possess dynamic filaments called Type IV pili (T4P) that perform diverse functions in colonization and dissemination, including host cell adhesion, DNA uptake, and secretion of protein substrates-exoproteins-from the periplasm to the extracellular space. The Vibrio cholerae toxin-coregulated pilus (TCP) and the enterotoxigenic Escherichia coli CFA/III pilus each mediates export of a single exoprotein, TcpF and CofJ, respectively. Here, we show that the disordered N-terminal segment of mature TcpF is the export signal (ES) recognized by TCP. Deletion of the ES disrupts secretion and causes TcpF to accumulate in the V. cholerae periplasm. The ES alone can mediate export of Neisseria gonorrhoeae FbpA by V. cholerae in a T4P-dependent manner. The ES is specific for its autologous T4P machinery as CofJ bearing the TcpF ES is exported by V. cholerae, whereas TcpF bearing the CofJ ES is not. Specificity is mediated by binding of the ES to TcpB, a minor pilin that primes pilus assembly and forms a trimer at the pilus tip. Finally, the ES is proteolyzed from the mature TcpF protein upon secretion. Together, these results provide a mechanism for delivery of TcpF across the outer membrane and release into the extracellular space.
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Affiliation(s)
- Minh Nguyen
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCV5A 1S6, Canada
| | - Tzu-Hui Wu
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCV5A 1S6, Canada
| | - Katie J. Danielson
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCV5A 1S6, Canada
| | - Nabeel M. Khan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCV5A 1S6, Canada
| | - John Zhijia Zhang
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCV5A 1S6, Canada
| | - Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BCV5A 1S6, Canada
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19
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Merfa MV, Zhu X, Shantharaj D, Gomez LM, Naranjo E, Potnis N, Cobine PA, De La Fuente L. Complete functional analysis of type IV pilus components of a reemergent plant pathogen reveals neofunctionalization of paralog genes. PLoS Pathog 2023; 19:e1011154. [PMID: 36780566 PMCID: PMC9956873 DOI: 10.1371/journal.ppat.1011154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/24/2023] [Accepted: 01/26/2023] [Indexed: 02/15/2023] Open
Abstract
Type IV pilus (TFP) is a multifunctional bacterial structure involved in twitching motility, adhesion, biofilm formation, as well as natural competence. Here, by site-directed mutagenesis and functional analysis, we determined the phenotype conferred by each of the 38 genes known to be required for TFP biosynthesis and regulation in the reemergent plant pathogenic fastidious prokaryote Xylella fastidiosa. This pathogen infects > 650 plant species and causes devastating diseases worldwide in olives, grapes, blueberries, and almonds, among others. This xylem-limited, insect-transmitted pathogen lives constantly under flow conditions and therefore is highly dependent on TFP for host colonization. In addition, TFP-mediated natural transformation is a process that impacts genomic diversity and environmental fitness. Phenotypic characterization of the mutants showed that ten genes were essential for both movement and natural competence. Interestingly, seven sets of paralogs exist, and mutations showed opposing phenotypes, indicating evolutionary neofunctionalization of subunits within TFP. The minor pilin FimT3 was the only protein exclusively required for natural competence. By combining approaches of molecular microbiology, structural biology, and biochemistry, we determined that the minor pilin FimT3 (but not the other two FimT paralogs) is the DNA receptor in TFP of X. fastidiosa and constitutes an example of neofunctionalization. FimT3 is conserved among X. fastidiosa strains and binds DNA non-specifically via an electropositive surface identified by homolog modeling. This protein surface includes two arginine residues that were exchanged with alanine and shown to be involved in DNA binding. Among plant pathogens, fimT3 was found in ~ 10% of the available genomes of the plant associated Xanthomonadaceae family, which are yet to be assessed for natural competence (besides X. fastidiosa). Overall, we highlight here the complex regulation of TFP in X. fastidiosa, providing a blueprint to understand TFP in other bacteria living under flow conditions.
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Affiliation(s)
- Marcus V. Merfa
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
| | - Xinyu Zhu
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America
| | - Deepak Shantharaj
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
| | - Laura M. Gomez
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
| | - Eber Naranjo
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
| | - Neha Potnis
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
| | - Paul A. Cobine
- Department of Biological Sciences, Auburn University, Auburn, Alabama, United States of America
| | - Leonardo De La Fuente
- Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America
- * E-mail:
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20
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Pseudomonas aeruginosa and Staphylococcus aureus Display Differential Proteomic Responses to the Silver(I) Compound, SBC3. Antibiotics (Basel) 2023; 12:antibiotics12020348. [PMID: 36830259 PMCID: PMC9952281 DOI: 10.3390/antibiotics12020348] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 01/27/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
The urgent need to combat antibiotic resistance and develop novel antimicrobial therapies has triggered studies on novel metal-based formulations. N-heterocyclic carbene (NHC) complexes coordinate transition metals to generate a broad range of anticancer and/or antimicrobial agents, with ongoing efforts being made to enhance the lipophilicity and drug stability. The lead silver(I) acetate complex, 1,3-dibenzyl-4,5-diphenylimidazol-2-ylidene (NHC*) (SBC3), has previously demonstrated promising growth and biofilm-inhibiting properties. In this work, the responses of two structurally different bacteria to SBC3 using label-free quantitative proteomics were characterised. Multidrug-resistant Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) are associated with cystic fibrosis lung colonisation and chronic wound infections, respectively. SBC3 increased the abundance of alginate biosynthesis, the secretion system and drug detoxification proteins in P. aeruginosa, whilst a variety of pathways, including anaerobic respiration, twitching motility and ABC transport, were decreased in abundance. This contrasted the affected pathways in S. aureus, where increased DNA replication/repair and cell redox homeostasis and decreased protein synthesis, lipoylation and glucose metabolism were observed. Increased abundance of cell wall/membrane proteins was indicative of the structural damage induced by SBC3 in both bacteria. These findings show the potential broad applications of SBC3 in treating Gram-positive and Gram-negative bacteria.
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21
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Wang L, Wong YC, Correira JM, Wancura M, Geiger CJ, Webster SS, Butler BJ, O’Toole GA, Langford RM, Brown KA, Dortdivanlioglu B, Webb L, Cosgriff-Hernandez E, Gordon VD. Bacterial mechanosensing of surface stiffness promotes signaling and growth leading to biofilm formation by Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525810. [PMID: 36747833 PMCID: PMC9900894 DOI: 10.1101/2023.01.26.525810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The attachment of bacteria onto a surface, consequent signaling, and the accumulation and growth of the surface-bound bacterial population are key initial steps in the formation of pathogenic biofilms. While recent reports have hinted that the stiffness of a surface may affect the accumulation of bacteria on that surface, the processes that underlie bacterial perception of and response to surface stiffness are unknown. Furthermore, whether, and how, the surface stiffness impacts biofilm development, after initial accumulation, is not known. We use thin and thick hydrogels to create stiff and soft composite materials, respectively, with the same surface chemistry. Using quantitative microscopy, we find that the accumulation, motility, and growth of the opportunistic human pathogen Pseudomonas aeruginosa respond to surface stiffness, and that these are linked through cyclic-di-GMP signaling that depends on surface stiffness. The mechanical cue stemming from surface stiffness is elucidated using finite-element modeling combined with experiments - adhesion to stiffer surfaces results in greater changes in mechanical stress and strain in the bacterial envelope than does adhesion to softer surfaces with identical surface chemistry. The cell-surface-exposed protein PilY1 acts as a mechanosensor, that upon surface engagement, results in higher cyclic-di-GMP levels, lower motility, and greater accumulation on stiffer surfaces. PilY1 impacts the biofilm lag phase, which is extended for bacteria attaching to stiffer surfaces. This study shows clear evidence that bacteria actively respond to different stiffness of surfaces where they adhere via perceiving varied mechanical stress and strain upon surface engagement.
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Affiliation(s)
- Liyun Wang
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX 78712, USA
- Present address: Max Planck Institute for Terrestrial Microbiology, Marburg, 35043, Germany
| | - Yu-Chern Wong
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX 78712, USA
- Department of Mechanical Engineering, The University of Texas at Austin, Austin, TX 78712, USA
| | - Joshua M. Correira
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712 USA
| | - Megan Wancura
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712 USA
| | - Chris J Geiger
- Geisel School of Medicine at Dartmouth, Hanover, NH 03755 USA
| | | | - Benjamin J. Butler
- Surfaces, Microstructure and Fracture Group, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | | | - Richard M. Langford
- Surfaces, Microstructure and Fracture Group, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
| | - Katherine A. Brown
- Surfaces, Microstructure and Fracture Group, Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom
- Oden Institute for Computational Engineering & Sciences, The University of Texas at Austin, Austin, TX 78712
| | - Berkin Dortdivanlioglu
- Department of Civil, Architectural, and Environmental Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Lauren Webb
- Department of Chemistry, The University of Texas at Austin, Austin, TX 78712 USA
| | | | - Vernita D. Gordon
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX 78712, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, TX 78712, USA
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX 78712, USA
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22
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Gao C, Chen Y, Cheng X, Zhang Y, Zhang Y, Wang Y, Cui Z, Liao Y, Luo P, Wu W, Wang C, Zeng H, Zou Q, Gu J. A novel structurally identified epitope delivered by macrophage membrane-coated PLGA nanoparticles elicits protection against Pseudomonas aeruginosa. J Nanobiotechnology 2022; 20:532. [PMID: 36517801 PMCID: PMC9750051 DOI: 10.1186/s12951-022-01725-x] [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: 05/01/2022] [Accepted: 11/28/2022] [Indexed: 12/15/2022] Open
Abstract
The increasing prevalence of antibiotic resistance by Pseudomonas aeruginosa (PA) raises an urgent need for an effective vaccine. The outer membrane proteins of PA, especially those that are upregulated during infection, are ideal vaccine targets. However, the strong hydrophobicity of these proteins hinders their application for this purpose. In this study, we selected eight outer membrane proteins from PA with the most significantly upregulated expression. Their extracellular loops were analyzed and screened by using sera from patients who had recovered from PA infection. As a result, a novel immunogenic epitope (Ep167-193) from PilY1 (PA4554) was found. Moreover, we constructed a macrophage membrane-coated PLGA (poly lactic-co-glycolic acid) nanoparticle vaccine carrying PilY1 Ep167-193 (PNPs@M-Ep167-193) that elicits a Th2 immune response and confers adequate protection in mice. Our data furnished the promising vaccine candidate PNPs@M-Ep167-193 while providing additional evidence for structure-based epitope identification and vaccine design.
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Affiliation(s)
- Chen Gao
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Yin Chen
- grid.410570.70000 0004 1760 6682State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing, Engineering Research Center for Nanomedicine, College of Preventive Medicine, Army Medical University, Chongqing, 400038 China
| | - Xin Cheng
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Yi Zhang
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Yueyue Zhang
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Ying Wang
- grid.410570.70000 0004 1760 6682953Th Hospital, Shigatse Branch, Xinqiao Hospital, Army Medical University, (Third Military Medical University), Shigatse, 857000 China
| | - Zhiyuan Cui
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Yaling Liao
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Ping Luo
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Weihui Wu
- grid.216938.70000 0000 9878 7032State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, China
| | - Cheng Wang
- grid.410570.70000 0004 1760 6682State Key Laboratory of Trauma, Burns and Combined Injury, Institute of Combined Injury of PLA, Chongqing, Engineering Research Center for Nanomedicine, College of Preventive Medicine, Army Medical University, Chongqing, 400038 China
| | - Hao Zeng
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Quanming Zou
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
| | - Jiang Gu
- grid.410570.70000 0004 1760 6682National Engineering Research Center of Immunological Products, Department of Microbiology and Biochemical Pharmacy, College of Pharmacy, Army Medical University, The 30th, Gaotanyan Street, Shapingba District, Chongqing, 400038 People’s Republic of China
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23
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Hughes HQ, Christman ND, Dalia TN, Ellison CK, Dalia AB. The PilT retraction ATPase promotes both extension and retraction of the MSHA type IVa pilus in Vibrio cholerae. PLoS Genet 2022; 18:e1010561. [PMID: 36542674 DOI: 10.1371/journal.pgen.1010561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/05/2023] [Accepted: 12/07/2022] [Indexed: 12/24/2022] Open
Abstract
Diverse bacterial species use type IVa pili (T4aP) to interact with their environments. The dynamic extension and retraction of T4aP is critical for their function, but the mechanisms that regulate this dynamic activity remain poorly understood. T4aP are typically extended via the activity of a dedicated extension motor ATPase and retracted via the action of an antagonistic retraction motor ATPase called PilT. These motors are generally functionally independent, and loss of PilT commonly results in T4aP hyperpiliation due to undeterred pilus extension. However, for the mannose-sensitive hemagglutinin (MSHA) T4aP of Vibrio cholerae, the loss of PilT unexpectedly results in a loss of surface piliation. Here, we employ a combination of genetic and cell biological approaches to dissect the underlying mechanism. Our results demonstrate that PilT is necessary for MSHA pilus extension in addition to its well-established role in promoting MSHA pilus retraction. Through a suppressor screen, we also provide genetic evidence that the MshA major pilin impacts pilus extension. Together, these findings contribute to our understanding of the factors that regulate pilus extension and describe a previously uncharacterized function for the PilT motor ATPase.
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Affiliation(s)
- Hannah Q Hughes
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Nicholas D Christman
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Triana N Dalia
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Courtney K Ellison
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
| | - Ankur B Dalia
- Department of Biology, Indiana University, Bloomington, Indiana, United States of America
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24
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Temporal Hierarchy and Context-Dependence of Quorum Sensing Signal in Pseudomonas aeruginosa. LIFE (BASEL, SWITZERLAND) 2022; 12:life12121953. [PMID: 36556318 PMCID: PMC9781131 DOI: 10.3390/life12121953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 11/24/2022]
Abstract
The Gram-negative bacterium Pseudomonas aeruginosa can cause infections in a broad range of hosts including plants, invertebrates and mammals and is an important source of nosocomial infections in humans. We were interested in how differences in the bacteria's nutritional environment impact bacterial communication and virulence factor production. We grew P. aeruginosa in 96 different conditions in BIOLOG Gen III plates and assayed quorum sensing (QS) signaling over the course of growth. We also quantified pyocyanin and biofilm production and the impact of sub-inhibitory exposure to tobramycin. We found that while 3-oxo-C12 homoserine lactone remained the dominant QS signal to be produced, timing of PQS production differed between media types. Further, whether cells grew predominantly as biofilms or planktonic cells was highly context dependent. Our data suggest that understanding the impact of the nutritional environment on the bacterium can lead to valuable insights into the link between bacterial physiology and pathology.
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25
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Xu S, Zhang Z, Xie X, Shi Y, Chai A, Fan T, Li B, Li L. Comparative genomics provides insights into the potential biocontrol mechanism of two Lysobacter enzymogenes strains with distinct antagonistic activities. Front Microbiol 2022; 13:966986. [PMID: 36033849 PMCID: PMC9410377 DOI: 10.3389/fmicb.2022.966986] [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: 06/12/2022] [Accepted: 07/27/2022] [Indexed: 11/29/2022] Open
Abstract
Lysobacter enzymogenes has been applied as an abundant beneficial microorganism to control plant disease; however, most L. enzymogenes strains have been mainly reported to control fungal diseases, not bacterial diseases. In this study, two L. enzymogenes strains were characterized, of which CX03 displayed a broad spectrum of antagonistic activities toward multiple bacteria, while CX06 exhibited a broad spectrum of antagonistic activities toward diverse fungi and oomycete, and the whole genomes of the two strains were sequenced and compared. The genome annotation showed that the CX03 genome comprised a 5,947,018 bp circular chromosome, while strain CX06 comprised a circular 6,206,196 bp chromosome. Phylogenetic analysis revealed that CX03 had a closer genetic relationship with L. enzymogenes ATCC29487T and M497-1, while CX06 was highly similar to L. enzymogenes C3. Functional gene annotation analyses of the two L. enzymogenes strains showed that many genes or gene clusters associated with the biosynthesis of different secondary metabolites were found in strains CX03 and CX06, which may be responsible for the different antagonistic activities against diverse plant pathogens. Moreover, comparative genomic analysis revealed the difference in bacterial secretory systems between L. enzymogenes strains CX03 and CX06. In addition, numerous conserved genes related to siderophore biosynthesis, quorum sensing, two-component systems, flagellar biosynthesis and chemotaxis were also identified in the genomes of strains CX03 and CX06. Most reported L. enzymogenes strains were proven mainly to suppress fungi, while CX03 exhibited direct inhibitory activities toward plant bacterial pathogens and showed an obvious role in managing bacterial disease. This study provides a novel understanding of the biocontrol mechanisms of L. enzymogenes, and reveals great potential for its application in plant disease control.
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26
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Yan L, Jin Y, Zhang B, Xu Y, Peng X, Qin S, Chen L. Diverse Aquatic Animal Matrices Play a Key Role in Survival and Potential Virulence of Non-O1/O139 Vibrio cholerae Isolates. Front Microbiol 2022; 13:896767. [PMID: 35801116 PMCID: PMC9255913 DOI: 10.3389/fmicb.2022.896767] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/04/2022] [Indexed: 11/13/2022] Open
Abstract
Vibrio cholerae can cause pandemic cholera in humans. The waterborne bacterium is frequently isolated from aquatic products worldwide. However, current literature on the impact of aquatic product matrices on the survival and pathogenicity of cholerae is rare. In this study, the growth of eleven non-O1/0O139 V. cholerae isolates recovered from eight species of commonly consumed fish and shellfish was for the first time determined in the eight aquatic animal matrices, most of which highly increased the bacterial biomass when compared with routine trypsin soybean broth (TSB) medium. Secretomes of the V. cholerae isolates (draft genome size: 3,852,021–4,144,013 bp) were determined using two-dimensional gel electrophoresis (2DE-GE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques. Comparative secretomic analyses revealed 74 differential extracellular proteins, including several virulence- and resistance-associated proteins secreted by the V. cholerae isolates when grown in the eight matrices. Meanwhile, a total of 8,119 intracellular proteins were identified, including 83 virulence- and 8 resistance-associated proteins, of which 61 virulence-associated proteins were absent from proteomes of these isolates when grown in the TSB medium. Additionally, comparative genomic and proteomic analyses also revealed several strain-specific proteins with unknown functions in the V. cholerae isolates. Taken, the results in this study demonstrate that distinct secretomes and proteomes induced by the aquatic animal matrices facilitate V. cholerae resistance in the edible aquatic animals and enhance the pathogenicity of the leading waterborne pathogen worldwide.
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Affiliation(s)
- Lili Yan
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yinzhe Jin
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Beiyu Zhang
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yingwei Xu
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Xu Peng
- Department of Biology, Archaea Centre, University of Copenhagen, Copenhagen, Denmark
| | - Si Qin
- Key Laboratory for Food Science and Biotechnology of Hunan Province, College of Food Science and Technology, Hunan Agricultural University, Changsha, China
- *Correspondence: Si Qin
| | - Lanming Chen
- Key Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs of the People's Republic of China, Shanghai, China
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Lanming Chen
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27
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Abstract
Type IV pili (T4P) are retractable multifunctional nanofibers present on the surface of numerous bacterial and archaeal species. Their importance to microbiology is difficult to overstate. The scientific journey leading to our current understanding of T4P structure and function has included many innovative research milestones. Although multiple T4P reviews over the years have emphasized recent advances, we find that current reports often omit many of the landmark discoveries in this field. Here, we attempt to highlight chronologically the most important work on T4P, from the discovery of pili to the application of sophisticated contemporary methods, which has brought us to our current state of knowledge. As there remains much to learn about the complex machine that assembles and retracts T4P, we hope that this review will increase the interest of current researchers and inspire innovative progress.
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28
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The Power of Touch: Type 4 Pili, the von Willebrand A Domain, and Surface Sensing by Pseudomonas aeruginosa. J Bacteriol 2022; 204:e0008422. [PMID: 35612303 PMCID: PMC9210963 DOI: 10.1128/jb.00084-22] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Most microbes in the biosphere are attached to surfaces, where they experience mechanical forces due to hydrodynamic flow and cell-to-substratum interactions. These forces likely serve as mechanical cues that influence bacterial physiology and eventually drive environmental adaptation and fitness. Mechanosensors are cellular components capable of sensing a mechanical input and serve as part of a larger system for sensing and transducing mechanical signals. Two cellular components in bacteria that have emerged as candidate mechanosensors are the type IV pili (TFP) and the flagellum. Current models posit that bacteria transmit and convert TFP- and/or flagellum-dependent mechanical force inputs into biochemical signals, including cAMP and c-di-GMP, to drive surface adaptation. Here, we discuss the impact of force-induced changes on the structure and function of two eukaryotic proteins, titin and the human von Willebrand factor (vWF), and these proteins’ relevance to bacteria. Given the wealth of understanding about these eukaryotic mechanosensors, we can use them as a framework to understand the effect of force on Pseudomonas aeruginosa during the early stages of biofilm formation, with a particular emphasis on TFP and the documented surface-sensing mechanosensors PilY1 and FimH. We also discuss the importance of disulfide bonds in mediating force-induced conformational changes, which may modulate mechanosensing and downstream biochemical signaling. We conclude by sharing our perspective on the state of the field and what we deem exciting frontiers in studying bacterial mechanosensing to better understand the mechanisms whereby bacteria transition from a planktonic to a biofilm lifestyle.
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29
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Filloux A. Bacterial protein secretion systems: Game of types. MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 35536734 DOI: 10.1099/mic.0.001193] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Protein trafficking across the bacterial envelope is a process that contributes to the organisation and integrity of the cell. It is the foundation for establishing contact and exchange between the environment and the cytosol. It helps cells to communicate with one another, whether they establish symbiotic or competitive behaviours. It is instrumental for pathogenesis and for bacteria to subvert the host immune response. Understanding the formation of envelope conduits and the manifold strategies employed for moving macromolecules across these channels is a fascinating playground. The diversity of the nanomachines involved in this process logically resulted in an attempt to classify them, which is where the protein secretion system types emerged. As our knowledge grew, so did the number of types, and their rightful nomenclature started to be questioned. While this may seem a semantic or philosophical issue, it also reflects scientific rigour when it comes to assimilating findings into textbooks and science history. Here I give an overview on bacterial protein secretion systems, their history, their nomenclature and why it can be misleading for newcomers in the field. Note that I do not try to suggest a new nomenclature. Instead, I explore the reasons why naming could have escaped our control and I try to reiterate basic concepts that underlie protein trafficking cross membranes.
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Affiliation(s)
- Alain Filloux
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, SW7 2AZ, UK
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30
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The molecular basis of FimT-mediated DNA uptake during bacterial natural transformation. Nat Commun 2022; 13:1065. [PMID: 35246533 PMCID: PMC8897410 DOI: 10.1038/s41467-022-28690-1] [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: 07/16/2021] [Accepted: 02/08/2022] [Indexed: 01/05/2023] Open
Abstract
Naturally competent bacteria encode sophisticated protein machinery for the uptake and translocation of exogenous DNA into the cell. If this DNA is integrated into the bacterial genome, the bacterium is said to be naturally transformed. Most competent bacterial species utilise type IV pili for the initial DNA uptake step. These proteinaceous cell-surface structures are composed of thousands of pilus subunits (pilins), designated as major or minor according to their relative abundance in the pilus. Here, we show that the minor pilin FimT plays an important role in the natural transformation of Legionella pneumophila. We use NMR spectroscopy, in vitro DNA binding assays and in vivo transformation assays to understand the molecular basis of FimT's role in this process. FimT binds to DNA via an electropositive patch, rich in arginines, several of which are well-conserved and located in a conformationally flexible C-terminal tail. FimT orthologues from other Gammaproteobacteria share the ability to bind to DNA. Our results suggest that FimT plays an important role in DNA uptake in a wide range of competent species.
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31
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Abstract
The opportunistic pathogen Pseudomonas aeruginosa relies upon type IV pili (Tfp) for host colonization and virulence. Tfp are retractile surface appendages that promote adherence to host tissue and mediate twitching motility, a form of surface-associated translocation. Tfp are composed of a major structural pilin protein (PilA), several less abundant, fiber-associated pilin-like proteins (FimU, PilV, PilW, PilX, and PilE), and a pilus-associated tip adhesin and surface sensor (PilY1). Several proteins critical for Tfp biogenesis and surface sensing are encoded by the fimU-pilVWXY1Y2E operon. Tfp biogenesis is regulated by the global transcription factor Vfr and its allosteric effector, cyclic AMP (cAMP). Our investigation into the basis for reduced Tfp production in cAMP/vfr mutants revealed a defect in the expression of the fimU operon. We found that cAMP/Vfr activation of the fimU operon occurs via direct binding of Vfr to a specific fimU promoter sequence. We also refined the role of the AlgZ/AlgR two-component system in fimU regulation by demonstrating that phosphorylation of the response regulator AlgR is required for maximal binding to the fimU promoter region in vitro. Vfr also regulates expression of the algZR operon, revealing an indirect regulatory loop affecting fimU operon transcription. Overall, these results demonstrate that two linked but independent regulatory systems couple the expression of Tfp biogenesis and surface sensing genes and highlight the regulatory complexity governing expression of P. aeruginosa virulence factors. IMPORTANCE Pseudomonas aeruginosa is an opportunistic pathogen responsible for a wide range of infections. An extensive repertoire of virulence factors aid in P. aeruginosa pathogenesis. Type IV pili (Tfp) play a critical role in host colonization and infection by promoting adherence to host tissue, facilitating twitching motility and mediating surface-associated behaviors. The fimU operon encodes several pilus-associated proteins that are essential for proper Tfp function and surface sensing. In this study, we report that linked but independent regulatory systems dictate Tfp biogenesis. We also demonstrated the importance of different phosphorylation states of the AlgZ/AlgR two-component system and its role in Tfp biogenesis. Overall, this study furthers our understanding of the complex regulatory mechanisms that govern the production of a critical and multifaceted virulence factor.
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32
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Abstract
Neisseria gonorrhoeae is an obligate human pathogen that is the cause of the sexually transmitted disease gonorrhoea. Recently, there has been a surge in gonorrhoea cases that has been exacerbated by the rapid rise in gonococcal multidrug resistance to all useful antimicrobials resulting in this organism becoming a significant public health burden. Therefore, there is a clear and present need to understand the organism's biology through its physiology and pathogenesis to help develop new intervention strategies. The gonococcus initially colonises and adheres to host mucosal surfaces utilising a type IV pilus that helps with microcolony formation. Other adhesion strategies include the porin, PorB, and the phase variable outer membrane protein Opa. The gonococcus is able to subvert complement mediated killing and opsonisation by sialylation of its lipooligosaccharide and deploys a series of anti-phagocytic mechanisms. N. gonorrhoeae is a fastidious organism that is able to grow on a limited number of primary carbon sources such as glucose and lactate. The utilization of lactate by the gonococcus has been implicated in a number of pathogenicity mechanisms. The bacterium lives mainly in microaerobic environments and can grow both aerobically and anaerobically with the aid of nitrite. The gonococcus does not produce siderophores for scavenging iron but can utilize some produced by other bacteria, and it is able to successful chelate iron from host haem, transferrin and lactoferrin. The gonococcus is an incredibly versatile human pathogen; in the following chapter, we detail the intricate mechanisms used by the bacterium to invade and survive within the host.
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Affiliation(s)
- Luke R Green
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Joby Cole
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Ernesto Feliz Diaz Parga
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Jonathan G Shaw
- Department of Infection, Immunity & Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom.
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33
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A noncanonical cytochrome c stimulates calcium binding by PilY1 for type IVa pili formation. Proc Natl Acad Sci U S A 2022; 119:2115061119. [PMID: 35121662 PMCID: PMC8833165 DOI: 10.1073/pnas.2115061119] [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] [Accepted: 12/28/2021] [Indexed: 12/23/2022] Open
Abstract
Type IVa pili (T4aP) are versatile bacterial cell surface structures that undergo extension/adhesion/retraction cycles powered by the cell envelope-spanning T4aP machine. In this machine, a complex composed of four minor pilins and PilY1 primes T4aP extension and is also present at the pilus tip mediating adhesion. Similar to many several other bacteria, Myxococcus xanthus contains multiple minor pilins/PilY1 sets that are incompletely understood. Here, we report that minor pilins and PilY1 (PilY1.1) of cluster_1 form priming and tip complexes contingent on calcium and a noncanonical cytochrome c (TfcP) with an unusual His/Cys heme ligation. We provide evidence that TfcP is unlikely to participate in electron transport and instead stimulates calcium binding by PilY1.1 at low-calcium concentrations, thereby stabilizing PilY1.1 and enabling T4aP function in a broader range of calcium concentrations. These results not only identify a previously undescribed function of cytochromes c but also illustrate how incorporation of an accessory factor expands the environmental range under which the T4aP system functions.
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34
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Hu Y, Zheng J, Zhang J. Natural Transformation in Acinetobacter baumannii W068: A Genetic Analysis Reveals the Involvements of the CRP, XcpV, XcpW, TsaP, and TonB2. Front Microbiol 2022; 12:738034. [PMID: 35126321 PMCID: PMC8811193 DOI: 10.3389/fmicb.2021.738034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 12/14/2021] [Indexed: 01/25/2023] Open
Abstract
Acinetobacter baumannii is a serious threat to public health, and there is increasing attention to the development of antibiotic resistance in this bacterium. Natural transformation is a major horizontal gene transfer mechanism that can lead to antibiotic resistance. To better understand the mechanism of natural transformation in A. baumannii, we selected a clinical isolate that was transformable but had no visible extracellular type IV pili (T4P) filaments and then examined the effects of multiple single-gene knockouts on natural plasmid transformation. Among 33 candidate genes, 28 knockout mutants had severely or completely impaired transformability. Some of these genes had established roles in T4P biogenesis; DNA transfer across the outer membrane, periplasm, or inner membrane; and protection of intracellular single-stranded DNA (ssDNA). Other genes had no previously reported roles in natural transformation of A. baumannii, including competence activator cAMP receptor protein (CRP), a periplasmic protein that may function in T4P assembly (TonB2), a T4P secretin-associated protein (TsaP), and two type II secretion system (T2SS) minor pseudopilus assembly prime complex competent proteins (XcpV and XcpW). The deletion of the T2SS assembly platform protein X had no effect on transformation, and the minor pseudopilins were capable of initiating major pilin assembly. Thus, we speculate that XcpV and XcpW may function in DNA uptake with major pilin assembly, a non-T2SS-dependent mechanism and that a competence pseudopilus similar to T4P constituted the central part of the DNA uptake complex. These results may help guide future research on the alarming increase of antibiotic resistance in this pathogen.
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Affiliation(s)
- Yuan Hu
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Junjie Zheng
- The Fifth Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Jianzhong Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
- *Correspondence: Jianzhong Zhang,
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35
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Oliveira V, Aschtgen MS, van Erp A, Henriques-Normark B, Muschiol S. The Role of Minor Pilins in Assembly and Function of the Competence Pilus of Streptococcus pneumoniae. Front Cell Infect Microbiol 2022; 11:808601. [PMID: 35004361 PMCID: PMC8727766 DOI: 10.3389/fcimb.2021.808601] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 11/30/2021] [Indexed: 12/03/2022] Open
Abstract
The remarkable genomic plasticity of Streptococcus pneumoniae largely depends on its ability to undergo natural genetic transformation. To take up extracellular DNA, S. pneumoniae assembles competence pili composed of the major pilin ComGC. In addition to ComGC, four minor pilins ComGD, E, F, and G are expressed during bacterial competence, but their role in pilus biogenesis and transformation is unknown. Here, using a combination of protein-protein interaction assays we show that all four proteins can directly interact with each other. Pneumococcal ComGG stabilizes the minor pilin ComGD and ComGF and can interact with and stabilize the major pilin ComGC, thus, deletion of ComGG abolishes competence pilus assembly. We further demonstrate that minor pilins are present in sheared pili fractions and find ComGF to be incorporated along the competence pilus by immunofluorescence and electron microscopy. Finally, mutants of the invariant Glu5 residue (E5), ComGDE5A or ComGEE5A, but not ComGFE5A, were severely impaired in pilus formation and function. Together, our results suggest that ComGG, lacking E5, is essential for competence pilus assembly and function, and plays a central role in connecting the pneumococcal minor pilins to ComGC.
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Affiliation(s)
- Vitor Oliveira
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | | | - Anke van Erp
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
| | - Sandra Muschiol
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden
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36
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Nolan C, Behrends V. Sub-Inhibitory Antibiotic Exposure and Virulence in Pseudomonas aeruginosa. Antibiotics (Basel) 2021; 10:antibiotics10111393. [PMID: 34827331 PMCID: PMC8615142 DOI: 10.3390/antibiotics10111393] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/20/2022] Open
Abstract
Pseudomonas aeruginosa is a prime opportunistic pathogen, one of the most important causes of hospital-acquired infections and the major cause of morbidity and mortality in cystic fibrosis lung infections. One reason for the bacterium's pathogenic success is the large array of virulence factors that it can employ. Another is its high degree of intrinsic and acquired resistance to antibiotics. In this review, we first summarise the current knowledge about the regulation of virulence factor expression and production. We then look at the impact of sub-MIC antibiotic exposure and find that the virulence-antibiotic interaction for P. aeruginosa is antibiotic-specific, multifaceted, and complex. Most studies undertaken to date have been in vitro assays in batch culture systems, involving short-term (<24 h) antibiotic exposure. Therefore, we discuss the importance of long-term, in vivo-mimicking models for future work, particularly highlighting the need to account for bacterial physiology, which by extension governs both virulence factor expression and antibiotic tolerance/resistance.
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37
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Ellison CK, Whitfield GB, Brun YV. Type IV Pili: Dynamic Bacterial Nanomachines. FEMS Microbiol Rev 2021; 46:6425739. [PMID: 34788436 DOI: 10.1093/femsre/fuab053] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/08/2021] [Indexed: 01/19/2023] Open
Abstract
Bacteria and archaea rely on appendages called type IV pili (T4P) to participate in diverse behaviors including surface sensing, biofilm formation, virulence, protein secretion, and motility across surfaces. T4P are broadly distributed fibers that dynamically extend and retract, and this dynamic activity is essential for their function in broad processes. Despite the essentiality of dynamics in T4P function, little is known about the role of these dynamics and molecular mechanisms controlling them. Recent advances in microscopy have yielded insight into the role of T4P dynamics in their diverse functions and recent structural work has expanded what is known about the inner workings of the T4P motor. This review discusses recent progress in understanding the function, regulation, and mechanisms of T4P dynamics.
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Affiliation(s)
- Courtney K Ellison
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA.,Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Gregory B Whitfield
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
| | - Yves V Brun
- Département de Microbiologie, Infectiologie et Immunologie, Université de Montréal, Montréal, Québec, Canada
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38
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Barnier JP, Meyer J, Kolappan S, Bouzinba-Ségard H, Gesbert G, Jamet A, Frapy E, Schönherr-Hellec S, Capel E, Virion Z, Dupuis M, Bille E, Morand P, Schmitt T, Bourdoulous S, Nassif X, Craig L, Coureuil M. The minor pilin PilV provides a conserved adhesion site throughout the antigenically variable meningococcal type IV pilus. Proc Natl Acad Sci U S A 2021; 118:e2109364118. [PMID: 34725157 PMCID: PMC8609321 DOI: 10.1073/pnas.2109364118] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 09/16/2021] [Indexed: 01/14/2023] Open
Abstract
Neisseria meningitidis utilizes type IV pili (T4P) to adhere to and colonize host endothelial cells, a process at the heart of meningococcal invasive diseases leading to meningitis and sepsis. T4P are polymers of an antigenically variable major pilin building block, PilE, plus several core minor pilins that initiate pilus assembly and are thought to be located at the pilus tip. Adhesion of N. meningitidis to human endothelial cells requires both PilE and a conserved noncore minor pilin PilV, but the localization of PilV and its precise role in this process remains to be clarified. Here, we show that both PilE and PilV promote adhesion to endothelial vessels in vivo. The substantial adhesion defect observed for pilV mutants suggests it is the main adhesin. Consistent with this observation, superresolution microscopy showed the abundant distribution of PilV throughout the pilus. We determined the crystal structure of PilV and modeled it within the pilus filament. The small size of PilV causes it to be recessed relative to adjacent PilE subunits, which are dominated by a prominent hypervariable loop. Nonetheless, we identified a conserved surface-exposed adhesive loop on PilV by alanine scanning mutagenesis. Critically, antibodies directed against PilV inhibit N. meningitidis colonization of human skin grafts. These findings explain how N. meningitidis T4P undergo antigenic variation to evade the humoral immune response while maintaining their adhesive function and establish the potential of this highly conserved minor pilin as a vaccine and therapeutic target for the prevention and treatment of N. meningitidis infections.
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Affiliation(s)
- Jean-Philippe Barnier
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Julie Meyer
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Subramania Kolappan
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada
| | - Haniaa Bouzinba-Ségard
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1016, CNRS UMR 8104, Institut Cochin, Paris 75014, France
| | - Gaël Gesbert
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Anne Jamet
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Eric Frapy
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Sophia Schönherr-Hellec
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Elena Capel
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Zoé Virion
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Marion Dupuis
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
| | - Emmanuelle Bille
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Philippe Morand
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Bactériologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Cochin, Paris 75014, France
| | - Taliah Schmitt
- Service de Chirurgie Reconstructrice et Plastique, Groupe Hospitalier Paris Saint-Joseph, Paris 75014, France
| | - Sandrine Bourdoulous
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1016, CNRS UMR 8104, Institut Cochin, Paris 75014, France
| | - Xavier Nassif
- Faculté de Médecine, Université de Paris, Paris 75006, France
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
- Service de Microbiologie, Assistance Publique-Hôpitaux de Paris, Centre-Université de Paris, Hôpital Necker Enfants-Malades, Paris 75015, France
| | - Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC V5A 3Y6, Canada;
| | - Mathieu Coureuil
- Faculté de Médecine, Université de Paris, Paris 75006, France;
- INSERM U1151, CNRS UMR 8253, Institut Necker Enfants-Malades, Paris 75015, France
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Corral J, Pérez-Varela M, Sánchez-Osuna M, Cortés P, Barbé J, Aranda J. Importance of twitching and surface-associated motility in the virulence of Acinetobacter baumannii. Virulence 2021; 12:2201-2213. [PMID: 34515614 PMCID: PMC8451467 DOI: 10.1080/21505594.2021.1950268] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Acinetobacter baumannii is a pathogen of increasing clinical importance worldwide, especially given its ability to readily acquire resistance determinants. Motile strains of this bacterium can move by either or both of two types of motility: (i) twitching, driven by type IV pili, and (ii) surface-associated motility, an appendage-independent form of movement. A. baumannii strain MAR002 possesses both twitching and surface-associated motility. In this study, we isolated spontaneous rifampin-resistant mutants of strain MAR002 in which point mutations in the rpoB gene were identified that resulted in an altered motility pattern. Transcriptomic analysis of mutants lacking twitching, surface-associated motility, or both led to the identification of deregulated genes within each motility phenotype, based on their level of expression and their biological function. Investigations of the corresponding knockout mutants revealed several genes involved in the motility of A. baumannii strain MAR002, including two involved in twitching (encoding a minor pilin subunit and an RND [resistance nodulation division] component), one in surface-associated motility (encoding an amino acid permease), and eight in both (encoding RND and ABC components, the energy transducer TonB, the porin OprD, the T6SS component TagF, an IclR transcriptional regulator, a PQQ-dependent sugar dehydrogenase, and a putative pectate lyase). Virulence assays showed the reduced pathogenicity of mutants with impairments in both types of motility or in surface-associated motility alone. By contrast, the virulence of twitching-affected mutants was not affected. These results shed light on the key role of surface-associated motility and the limited role of twitching in the pathogenicity of A. baumannii.
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Affiliation(s)
- Jordi Corral
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - María Pérez-Varela
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Miquel Sánchez-Osuna
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Pilar Cortés
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Jordi Barbé
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
| | - Jesús Aranda
- Departament De Genètica I Microbiologia, Facultat De Biociènces, Universitat Autònoma De Barcelona, Barcelona, Spain
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40
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Abstract
Bacteria thrive both in liquids and attached to surfaces. The concentration of bacteria on surfaces is generally much higher than in the surrounding environment, offering bacteria ample opportunity for mutualistic, symbiotic, and pathogenic interactions. To efficiently populate surfaces, they have evolved mechanisms to sense mechanical or chemical cues upon contact with solid substrata. This is of particular importance for pathogens that interact with host tissue surfaces. In this review we discuss how bacteria are able to sense surfaces and how they use this information to adapt their physiology and behavior to this new environment. We first survey mechanosensing and chemosensing mechanisms and outline how specific macromolecular structures can inform bacteria about surfaces. We then discuss how mechanical cues are converted to biochemical signals to activate specific cellular processes in a defined chronological order and describe the role of two key second messengers, c-di-GMP and cAMP, in this process.
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Affiliation(s)
| | - Urs Jenal
- Biozentrum, University of Basel, CH-4056 Basel, Switzerland; ,
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41
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Exploiting pilus-mediated bacteria-host interactions for health benefits. Mol Aspects Med 2021; 81:100998. [PMID: 34294411 DOI: 10.1016/j.mam.2021.100998] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/30/2021] [Accepted: 07/16/2021] [Indexed: 02/06/2023]
Abstract
Surface pili (or fimbriae) are an important but conspicuous adaptation of several genera and species of Gram-negative and Gram-positive bacteria. These long and non-flagellar multi-subunit adhesins mediate the initial contact that a bacterium has with a host or environment, and thus have come to be regarded as a key colonization factor for virulence activity in pathogens or niche adaptation in commensals. Pili in pathogenic bacteria are well recognized for their roles in the adhesion to host cells, colonization of tissues, and establishment of infection. As an 'anti-adhesive' ploy, targeting pilus-mediated attachment for disruption has become a potentially effective alternative to using antibiotics. In this review, we give a description of the several structurally distinct bacterial pilus types thus far characterized, and as well offer details about the intricacy of their individual structure, assembly, and function. With a molecular understanding of pilus biogenesis and pilus-mediated host interactions also provided, we go on to describe some of the emerging new approaches and compounds that have been recently developed to prevent the adhesion, colonization, and infection of piliated bacterial pathogens.
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42
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Structural interactions define assembly adapter function of a type II secretion system pseudopilin. Structure 2021; 29:1116-1127.e8. [PMID: 34139172 DOI: 10.1016/j.str.2021.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 03/15/2021] [Accepted: 05/28/2021] [Indexed: 01/13/2023]
Abstract
The type IV filament superfamily comprises widespread membrane-associated polymers in prokaryotes. The type II secretion system (T2SS), a virulence pathway in many pathogens, belongs to this superfamily. A knowledge gap in understanding of the T2SS is the molecular role of a small "pseudopilin" protein. Using multiple biophysical techniques, we have deciphered how this missing component of the Xcp T2SS architecture is structurally integrated, and thereby unlocked its function. We demonstrate that low-abundance XcpH is the adapter that bridges a trimeric initiating tip complex, XcpIJK, with a periplasmic filament of XcpG subunits. Each pseudopilin protein caps an XcpG protofilament in an overall pseudopilus compatible with dimensions of the periplasm and the outer membrane-spanning secretin through which substrates pass. Unexpectedly, to fulfill its adapter function, the XcpH N-terminal helix must be unwound, a property shared with XcpG subunits. We provide an experimentally validated three-dimensional structural model of a complete type IV filament.
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43
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Oeser S, Wallner T, Schuergers N, Bučinská L, Sivabalasarma S, Bähre H, Albers SV, Wilde A. Minor pilins are involved in motility and natural competence in the cyanobacterium Synechocystis sp. PCC 6803. Mol Microbiol 2021; 116:743-765. [PMID: 34115422 DOI: 10.1111/mmi.14768] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 06/04/2021] [Accepted: 06/05/2021] [Indexed: 11/28/2022]
Abstract
Cyanobacteria synthesize type IV pili, which are known to be essential for motility, adhesion and natural competence. They consist of long flexible fibers that are primarily composed of the major pilin PilA1 in Synechocystis sp. PCC 6803. In addition, Synechocystis encodes less abundant pilin-like proteins, which are known as minor pilins. In this study, we show that the minor pilin PilA5 is essential for natural transformation but is dispensable for motility and flocculation. In contrast, a set of minor pilins encoded by the pilA9-slr2019 transcriptional unit are necessary for motility but are dispensable for natural transformation. Neither pilA5-pilA6 nor pilA9-slr2019 are essential for pilus assembly as mutant strains showed type IV pili on the cell surface. Three further gene products with similarity to PilX-like minor pilins have a function in flocculation of Synechocystis. The results of our study indicate that different minor pilins facilitate distinct pilus functions. Further, our microarray analysis demonstrated that the transcription levels of the minor pilin genes change in response to surface contact. A total of 122 genes were determined to have altered transcription between planktonic and surface growth, including several plasmid genes which are involved exopolysaccharide synthesis and the formation of bloom-like aggregates.
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Affiliation(s)
- Sabrina Oeser
- Molecular Genetics, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Thomas Wallner
- Molecular Genetics, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Nils Schuergers
- Molecular Genetics, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Lenka Bučinská
- Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Trebon, Czech Republic
| | - Shamphavi Sivabalasarma
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Heike Bähre
- Research Core Unit Metabolomics, Medical School Hannover, Hannover, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Institute of Biology II, University of Freiburg, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine, University of Freiburg, Freiburg, Germany
| | - Annegret Wilde
- Molecular Genetics, Institute of Biology III, University of Freiburg, Freiburg, Germany
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Abstract
During biofilm formation, the opportunistic pathogen Pseudomonas aeruginosa uses its type IV pili (TFP) to sense a surface, eliciting increased second-messenger production and regulating target pathways required to adapt to a surface lifestyle. The mechanisms whereby TFP detect surface contact are still poorly understood, although mechanosensing is often invoked, with few data supporting this claim. Using a combination of molecular genetics and single-cell analysis, with biophysical, biochemical, and genomics techniques, we show that force-induced changes mediated by the von Willebrand A (vWA) domain-containing, TFP tip-associated protein PilY1 are required for surface sensing. Atomic force microscopy shows that TFP/PilY1 can undergo force-induced, sustained conformational changes akin to those observed for mechanosensitive proteins like titin. We show that mutation of a single cysteine residue in the vWA domain of PilY1 results in modestly lower surface adhesion forces, reduced sustained conformational changes, and increased nanospring-like properties, as well as reduced c-di-GMP signaling and biofilm formation. Mutating this cysteine has allowed us to genetically separate a role for TFP in twitching motility from surface-sensing signaling. The conservation of this Cys residue in all P. aeruginosa PA14 strains and its absence in the ∼720 sequenced strains of P. aeruginosa PAO1 may contribute to explaining the observed differences in surface colonization strategies observed for PA14 versus PAO1. IMPORTANCE Most bacteria live on abiotic and biotic surfaces in surface-attached communities known as biofilms. Surface sensing and increased levels of the second-messenger molecule c-di-GMP are crucial to the transition from planktonic to biofilm growth. The mechanism(s) underlying TFP-mediated surface detection that triggers this c-di-GMP signaling cascade is unclear. Here, we provide key insight into this question; we show that the eukaryote-like vWA domain of the TFP tip-associated protein PilY1 responds to mechanical force, which in turn drives the production of a key second messenger needed to regulate surface behaviors. Our studies highlight a potential mechanism that may account for differing surface colonization strategies.
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45
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Decreased Biofilm Formation Ability of a Multidrug-Resistant Pseudomonas aeruginosa Strain After Exposure to a Simulated Microgravity Environment. Jundishapur J Microbiol 2021. [DOI: 10.5812/jjm.100465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: The refractory infection induced by multidrug-resistant (MDR) Pseudomonas aeruginosa has become one of the most urgent problems in hospitals. The biofilms formed by P. aeruginosa increase its resistance to antibiotics. A simulated microgravity (SMG) environment provides a platform to understand the factors affecting biofilm formation in bacteria. Objectives: This study aimed to investigate the SMG effects on MDR P. aeruginosa biofilm formation and explore the relevant mechanisms. Methods: In this study, a clinostat was used to simulate a microgravity (MG) environment. The motility and biofilm formation ability of MDR P. aeruginosa were observed using the swimming test and the crystal violet staining method, respectively. The underlying mechanism of phenotypic changes was further investigated by comparative transcriptomic analysis. Results: Multidrug-resistant P. aeruginosa grown under the SMG condition exhibited decreased swimming motility and biofilm formation ability compared to those under the normal gravity (NG) condition. Further analysis revealed that the decreased swimming motility and biofilm formation ability could be attributed to the downregulated expression of genes responsible for flagellar synthesis (flhB, fliQ, and fliR) and type IV pili biogenesis (pilDEXY1Y2VW). Conclusions: This is the first study to perform experiments on MDR P. aeruginosa under the SMG condition. It will be beneficial to understand the mechanism of MDR P. aeruginosa biofilm formation and develop new treatment strategies for infectious diseases induced by MDR P. aeruginosa in the future.
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46
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CryoEM map of Pseudomonas aeruginosa PilQ enables structural characterization of TsaP. Structure 2020; 29:457-466.e4. [PMID: 33338410 DOI: 10.1016/j.str.2020.11.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 10/22/2020] [Accepted: 11/24/2020] [Indexed: 01/22/2023]
Abstract
The type IV pilus machinery is a multi-protein complex that polymerizes and depolymerizes a pilus fiber used for attachment, twitching motility, phage adsorption, natural competence, protein secretion, and surface-sensing. An outer membrane secretin pore is required for passage of the pilus fiber out of the cell. Herein, the structure of the tetradecameric secretin, PilQ, from the Pseudomonas aeruginosa type IVa pilus system was determined to 4.3 Å and 4.4 Å resolution in the presence and absence of C7 symmetric spikes, respectively. The heptameric spikes were found to be two tandem C-terminal domains of TsaP. TsaP forms a belt around PilQ and while it is not essential for twitching motility, overexpression of TsaP triggers a signal cascade upstream of PilY1 leading to cyclic di-GMP up-regulation. These results resolve the identity of the spikes identified with Proteobacterial PilQ homologs and may reveal a new component of the surface-sensing cyclic di-GMP signal cascade.
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47
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Treuner-Lange A, Chang YW, Glatter T, Herfurth M, Lindow S, Chreifi G, Jensen GJ, Søgaard-Andersen L. PilY1 and minor pilins form a complex priming the type IVa pilus in Myxococcus xanthus. Nat Commun 2020; 11:5054. [PMID: 33028835 PMCID: PMC7541494 DOI: 10.1038/s41467-020-18803-z] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 09/14/2020] [Indexed: 01/05/2023] Open
Abstract
Type IVa pili are ubiquitous and versatile bacterial cell surface filaments that undergo cycles of extension, adhesion and retraction powered by the cell-envelope spanning type IVa pilus machine (T4aPM). The overall architecture of the T4aPM and the location of 10 conserved core proteins within this architecture have been elucidated. Here, using genetics, cell biology, proteomics and cryo-electron tomography, we demonstrate that the PilY1 protein and four minor pilins, which are widely conserved in T4aP systems, are essential for pilus extension in Myxococcus xanthus and form a complex that is an integral part of the T4aPM. Moreover, these proteins are part of the extended pilus. Our data support a model whereby the PilY1/minor pilin complex functions as a priming complex in T4aPM for pilus extension, a tip complex in the extended pilus for adhesion, and a cork for terminating retraction to maintain a priming complex for the next round of extension.
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Affiliation(s)
- Anke Treuner-Lange
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Yi-Wei Chang
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA, 91125, USA
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, 422 Curie Boulevard, Philadelphia, PA, 19104, USA
| | - Timo Glatter
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Marco Herfurth
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Steffi Lindow
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany
| | - Georges Chreifi
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA, 91125, USA
| | - Grant J Jensen
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA, 91125, USA
- Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Lotte Søgaard-Andersen
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch Str. 10, 35043, Marburg, Germany.
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48
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Ligthart K, Belzer C, de Vos WM, Tytgat HLP. Bridging Bacteria and the Gut: Functional Aspects of Type IV Pili. Trends Microbiol 2020; 28:340-348. [PMID: 32298612 DOI: 10.1016/j.tim.2020.02.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 01/31/2020] [Accepted: 02/10/2020] [Indexed: 12/14/2022]
Abstract
Cell-surface-located proteinaceous appendages, such as flagella and fimbriae or pili, are ubiquitous in bacterial communities. Here, we focus on conserved type IV pili (T4P) produced by bacteria in the intestinal tract, one of the most densely populated human ecosystems. Computational analysis revealed that approximately 30% of known intestinal bacteria are predicted to produce T4P. To rationalize how T4P allow intestinal bacteria to interact with their environment, other microbiota members, and host cells, we review their established role in gut commensals and pathogens with respect to adherence, motility, and biofilm formation, as well as protein secretion and DNA uptake. This work indicates that T4P are widely spread among the known members of the intestinal microbiota and that their contribution to human health might be underestimated.
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Affiliation(s)
- Kate Ligthart
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
| | - Clara Belzer
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands
| | - Willem M de Vos
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands; Research Program Human Microbiome, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hanne L P Tytgat
- Laboratory of Microbiology, Wageningen University, Wageningen, The Netherlands.
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49
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Craig L, Forest KT, Maier B. Type IV pili: dynamics, biophysics and functional consequences. Nat Rev Microbiol 2020; 17:429-440. [PMID: 30988511 DOI: 10.1038/s41579-019-0195-4] [Citation(s) in RCA: 222] [Impact Index Per Article: 55.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The surfaces of many bacteria are decorated with long, exquisitely thin appendages called type IV pili (T4P), dynamic filaments that are rapidly polymerized and depolymerized from a pool of pilin subunits. Cycles of pilus extension, binding and retraction enable T4P to perform a phenomenally diverse array of functions, including twitching motility, DNA uptake and microcolony formation. On the basis of recent developments, a comprehensive understanding is emerging of the molecular architecture of the T4P machinery and the filament it builds, providing mechanistic insights into the assembly and retraction processes. Combined microbiological and biophysical approaches have revealed how T4P dynamics influence self-organization of bacteria, how bacteria respond to external stimuli to regulate T4P activity for directed movement, and the role of T4P retraction in surface sensing. In this Review, we discuss the T4P machine architecture and filament structure and present current molecular models for T4P dynamics, with a particular focus on recent insights into T4P retraction. We also discuss the functional consequences of T4P dynamics, which have important implications for bacterial lifestyle and pathogenesis.
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Affiliation(s)
- Lisa Craig
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia, Canada.
| | - Katrina T Forest
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
| | - Berenike Maier
- Institute for Biological Physics, University of Cologne, Köln, Germany.
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50
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Bray MS, Wu J, Padilla CC, Stewart FJ, Fowle DA, Henny C, Simister RL, Thompson KJ, Crowe SA, Glass JB. Phylogenetic and structural diversity of aromatically dense pili from environmental metagenomes. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:49-57. [PMID: 31701641 PMCID: PMC7779115 DOI: 10.1111/1758-2229.12809] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 10/14/2019] [Accepted: 11/03/2019] [Indexed: 06/10/2023]
Abstract
Electroactive type IV pili, or e-pili, are used by some microbial species for extracellular electron transfer. Recent studies suggest that e-pili may be more phylogenetically and structurally diverse than previously assumed. Here, we used updated aromatic density thresholds (≥9.8% aromatic amino acids, ≤22-aa aromatic gaps and aromatic amino acids at residues 1, 24, 27, 50 and/or 51, and 32 and/or 57) to search for putative e-pilin genes in metagenomes from diverse ecosystems with active microbial metal cycling. Environmental putative e-pilins were diverse in length and phylogeny, and included truncated e-pilins in Geobacter spp., as well as longer putative e-pilins in Fe(II)-oxidizing Betaproteobacteria and Zetaproteobacteria.
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Affiliation(s)
- Marcus S. Bray
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Jieying Wu
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Cory C. Padilla
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Frank J. Stewart
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - David A. Fowle
- Department of Geology, University of Kansas, Lawrence, KS, USA
| | - Cynthia Henny
- Research Center for Limnology, Indonesian Institute of Sciences, Cibinong, Indonesia
| | - Rachel L. Simister
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Katharine J. Thompson
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
| | - Sean A. Crowe
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada
- Division of Earth and Planetary Sciences, School of Biological Sciences, and Swire Institute of Marine Science, The University of Hong Kong, Hong Kong
| | - Jennifer B. Glass
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, USA
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
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