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Jia Y, Zhang K, Cao J, Mao W. Correlation analysis of whole genome sequencing of a pathogenic Escherichia coli strain of Inner Mongolian origin. Sci Rep 2024; 14:15494. [PMID: 38969720 PMCID: PMC11226720 DOI: 10.1038/s41598-024-64256-5] [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: 10/21/2023] [Accepted: 06/06/2024] [Indexed: 07/07/2024] Open
Abstract
Anal swabs of 1-month-old Holstein calves with diarrhea were collected from an intensive cattle farm, and a highly pathogenic Escherichia coli strain was obtained by isolation and purification. To study the virulence and resistance genes of pathogenic E. coli that cause diarrhea in calves, a strain of E. coli E12 isolated from calf diarrhea samples was used as experimental material in this experiment, and the virulence of the E12 strain were identified by the mouse infection test, and the whole genome map of the E12 strain were obtained by whole-genome sequencing and analyzed for genome characterization. The results showed that the lethality of strain E12 was 100%, the total length of E12-encoded genes was 4,294,530 bp, Cluster of Orthologous Groups of proteins (COG) annotated to 4,194 functional genes, and the virulence genes of sequenced strain E12 were compared with the virulence genes of sequenced strain E12 from the Virulence Factors of Pathogenic Bacteria (VFDB), which contained a total of 366 virulence genes in sequenced strain E12. The analysis of virulence genes of E12 revealed a total of 52 virulence genes in the iron transferrin system, 56 virulence genes in the secretory system, 41 virulence genes in bacterial toxins, and a total of 217 virulence genes in the Adhesin and Invasins group. The antibiotic resistance genes of sequenced strain E12 were identified through the Antibiotic Resistance Genes Database (ARDB) and Comprehensive Antibiotic Research Database, and it was found that its chromosome and plasmid included a total of 127 antibiotic resistance genes in four classes, and that E12 carried 71 genes related to the antibiotic efflux pumps, 36 genes related to antibiotic inactivation, and 14 antibiotic target alteration and reduced penetration into antibiotics, and 6 antibiotic resistance genes, and the resistance phenotypes were consistent with the genotypes. The pathogenic E. coli that causes diarrhea in calves on this ranch contains a large number of virulence and resistance genes. The results provide a theoretical basis for the prevention and treatment of diarrhea and other diseases caused by E. coli disease.
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Affiliation(s)
- Yan Jia
- Xuzhou Vocational College of Bioengineering, Jiangsu, 221006, Xuzhou, China
| | - Kai Zhang
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Huhhot, 010018, Inner Mongolia, China
- Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Huhhot, 010018, Inner Mongolia, China
| | - Jinshan Cao
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Huhhot, 010018, Inner Mongolia, China.
- Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Huhhot, 010018, Inner Mongolia, China.
| | - Wei Mao
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Huhhot, 010018, Inner Mongolia, China.
- Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Huhhot, 010018, Inner Mongolia, China.
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Manisha Y, Srinivasan M, Jobichen C, Rosenshine I, Sivaraman J. Sensing for survival: specialised regulatory mechanisms of Type III secretion systems in Gram-negative pathogens. Biol Rev Camb Philos Soc 2024; 99:837-863. [PMID: 38217090 DOI: 10.1111/brv.13047] [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: 10/20/2021] [Revised: 12/14/2023] [Accepted: 12/19/2023] [Indexed: 01/15/2024]
Abstract
For centuries, Gram-negative pathogens have infected the human population and been responsible for numerous diseases in animals and plants. Despite advancements in therapeutics, Gram-negative pathogens continue to evolve, with some having developed multi-drug resistant phenotypes. For the successful control of infections caused by these bacteria, we need to widen our understanding of the mechanisms of host-pathogen interactions. Gram-negative pathogens utilise an array of effector proteins to hijack the host system to survive within the host environment. These proteins are secreted into the host system via various secretion systems, including the integral Type III secretion system (T3SS). The T3SS spans two bacterial membranes and one host membrane to deliver effector proteins (virulence factors) into the host cell. This multifaceted process has multiple layers of regulation and various checkpoints. In this review, we highlight the multiple strategies adopted by these pathogens to regulate or maintain virulence via the T3SS, encompassing the regulation of small molecules to sense and communicate with the host system, as well as master regulators, gatekeepers, chaperones, and other effectors that recognise successful host contact. Further, we discuss the regulatory links between the T3SS and other systems, like flagella and metabolic pathways including the tricarboxylic acid (TCA) cycle, anaerobic metabolism, and stringent cell response.
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Affiliation(s)
- Yadav Manisha
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Mahalashmi Srinivasan
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Chacko Jobichen
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, The Hebrew University of Jerusalem, Ein Kerem, Jerusalem, 91120, Israel
| | - J Sivaraman
- Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore
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Wang X, Zhu H, Hu J, Zhang B, Guo W, Wang Z, Wang D, Qi J, Tian M, Bao Y, Si F, Wang S. Genetic distribution, characterization, and function of Escherichia coli type III secretion system 2 (ETT2). iScience 2024; 27:109763. [PMID: 38706860 PMCID: PMC11068852 DOI: 10.1016/j.isci.2024.109763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024] Open
Abstract
Many Gram-negative bacteria use type Ⅲ secretion system (T3SS) to inject effector proteins and subvert host signaling pathways, facilitating the growth, survival, and virulence. Notably, some bacteria harbor multiple distinct T3SSs with different functions. An extraordinary T3SS, the Escherichia coli Type III Secretion System 2 (ETT2), is widespread among Escherichia coli (E. coli) strains. Since many ETT2 carry genetic mutations or deletions, it is thought to be nonfunctional. However, increasing studies highlight ETT2 contributes to E. coli pathogenesis. Here, we present a comprehensive overview of genetic distribution and characterization of ETT2. Subsequently, we outline its functional potential, contending that an intact ETT2 may retain the capacity to translocate effector proteins and manipulate the host's innate immune response. Given the potential zoonotic implications associated with ETT2-carrying bacteria, further investigations into the structure, function and regulation of ETT2 are imperative for comprehensive understanding of E. coli pathogenicity and the development of effective control strategies.
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Affiliation(s)
- Xinyu Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Hong Zhu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Jiangang Hu
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Beibei Zhang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Weiqi Guo
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Zhiyang Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Di Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Jingjing Qi
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Mingxing Tian
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Yanqing Bao
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
| | - Fusheng Si
- Institute of Animal Science and Veterinary Medicine, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Shaohui Wang
- Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Shanghai 200241, China
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Držmíšek J, Petráčková D, Dienstbier A, Čurnová I, Večerek B. T3SS chaperone of the CesT family is required for secretion of the anti-sigma factor BtrA in Bordetella pertussis. Emerg Microbes Infect 2023; 12:2272638. [PMID: 37850324 PMCID: PMC10732220 DOI: 10.1080/22221751.2023.2272638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 10/15/2023] [Indexed: 10/19/2023]
Abstract
Bordetella pertussis is a Gram-negative, strictly human re-emerging respiratory pathogen and the causative agent of whooping cough. Similar to other Gram-negative pathogens, B. pertussis produces the type III secretion system, but its role in the pathogenesis of B. pertussis is enigmatic and yet to be elucidated. Here, we combined RNA-seq, LC-MS/MS, and co-immunoprecipitation techniques to identify and characterize the novel CesT family T3SS chaperone BP2265. We show that this chaperone specifically interacts with the secreted T3SS regulator BtrA and represents the first non-flagellar chaperone required for the secretion of an anti-sigma factor. In its absence, secretion but not production of BtrA and most T3SS substrates is severely impaired. It appears that the role of BtrA in regulating T3SS extends beyond its activity as an antagonist of the sigma factor BtrS. Predictions made by artificial intelligence system AlphaFold support the chaperone function of BP2265 towards BtrA and outline the structural basis for the interaction of BtrA with its target BtrS. We propose to rename BP2265 to BtcB for the Bordetella type III chaperone of BtrA.In addition, the absence of the BtcB chaperone results in increased expression of numerous flagellar genes and several virulence genes. While increased production of flagellar proteins and intimin BipA translated into increased biofilm formation by the mutant, enhanced production of virulence factors resulted in increased cytotoxicity towards human macrophages. We hypothesize that these phenotypic traits result indirectly from impaired secretion of BtrA and altered activity of the BtrA/BtrS regulatory node.
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Affiliation(s)
- Jakub Držmíšek
- Laboratory of post-transcriptional control of gene expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Denisa Petráčková
- Laboratory of post-transcriptional control of gene expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ana Dienstbier
- Laboratory of post-transcriptional control of gene expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ivana Čurnová
- Laboratory of post-transcriptional control of gene expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Branislav Večerek
- Laboratory of post-transcriptional control of gene expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
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Wu Y, Zoller BGE, Kamal MAM, Hotop SK, Lehr CM, Brönstrup M, Dersch P, Empting M. Establishment of an In Bacterio Assay for the Assessment of Carbon Storage Regulator A (CsrA) Inhibitors. Chembiochem 2023; 24:e202300369. [PMID: 37435861 DOI: 10.1002/cbic.202300369] [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: 05/17/2023] [Revised: 07/12/2023] [Accepted: 07/12/2023] [Indexed: 07/13/2023]
Abstract
Polymicrobial infections involving various combinations of microorganisms, such as Escherichia, Pseudomonas, or Yersinia, can lead to acute and chronic diseases in for example the gastrointestinal and respiratory tracts. Our aim is to modulate microbial communities by targeting the posttranscriptional regulator system called carbon storage regulator A (CsrA) (or also repressor of secondary metabolites (RsmA)). In previous studies, we identified easily accessible CsrA binding scaffolds and macrocyclic CsrA binding peptides through biophysical screening and phage display technology. However, due to the lack of an appropriate in bacterio assay to evaluate the cellular effects of these inhibitor hits, the focus of the present study is to establish an in bacterio assay capable of probing and quantifying the impact on CsrA-regulated cellular mechanisms. We have successfully developed an assay based on a luciferase reporter gene assay, which in combination with a qPCR expression gene assay, allows for the monitoring of expression levels of different downstream targets of CsrA. The chaperone protein CesT was used as a suitable positive control for the assay, and in time-dependent experiments, we observed a CesT-mediated increase in bioluminescence over time. By this means, the cellular on-target effects of non-bactericidal/non-bacteriostatic virulence modulating compounds targeting CsrA/RsmA can be evaluated.
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Affiliation(s)
- Yingwen Wu
- Department of Antiviral & Antivirulence Drugs (AVID), Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123, Saarbrücken, Germany
- Cluster of Excellence RESIST (EXC 2155), Hanover Medical School, Carl-Neuberg-Straße 1, 30625, Hanover, Germany
| | - Ben G E Zoller
- Department of Antiviral & Antivirulence Drugs (AVID), Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123, Saarbrücken, Germany
| | - Mohamed Ashraf Mostafa Kamal
- Department of Drug Delivery (DDEL), Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
| | - Sven-Kevin Hotop
- Department of Chemical Biology, Helmholtz Centre for Infection Research, German Center for Infection Research (DZIF), 38124, Braunschweig, Germany
| | - Claus-Michael Lehr
- Department of Drug Delivery (DDEL), Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
| | - Mark Brönstrup
- Department of Chemical Biology, Helmholtz Centre for Infection Research, German Center for Infection Research (DZIF), 38124, Braunschweig, Germany
| | - Petra Dersch
- Institute of Infectiology, Center for Molecular Biology of Inflammation (ZMBE), University of Münster, 48149, Münster, Germany
| | - Martin Empting
- Department of Antiviral & Antivirulence Drugs (AVID), Helmholtz Institute for Pharmaceutical Research Saarland (HIPS), Saarland University, 66123, Saarbrücken, Germany
- Department of Pharmacy, Saarland University, 66123, Saarbrücken, Germany
- Cluster of Excellence RESIST (EXC 2155), Hanover Medical School, Carl-Neuberg-Straße 1, 30625, Hanover, Germany
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Jia Y, Mao W, Liu B, Zhang S, Cao J, Xu X. Study on the drug resistance and pathogenicity of Escherichia coli isolated from calf diarrhea and the distribution of virulence genes and antimicrobial resistance genes. Front Microbiol 2022; 13:992111. [PMID: 36620061 PMCID: PMC9815963 DOI: 10.3389/fmicb.2022.992111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Introduction The unscientific and irrational use of antimicrobial drugs in dairy farms has led to the emergence of more serious drug resistance in Escherichia coli. Methods In this study, cases of calf diarrhea in cattle farms around the Hohhot area were studied, and Escherichia coli were identified by PCR and biochemical methods, while the distribution of virulence and drug resistance genes of the isolates was analyzed. Results The results showed that 21 strains of Escherichia coli were isolated from the diseased materials, and the isolation rate was 60%. The isolated strains belong to 15 ST types. The drug resistance levels of the isolated strains to 20 kinds of antimicrobial agent viz., penicillin, ampicillin, cefotaxime, cefepime, cefoxitin, and ceftriaxone were more than 50%. The resistance rate to meropenem was 10%. The resistance rates to tetracycline and doxycycline were 33% and 29%, to ciprofloxacin, levofloxacin and enrofloxacin were 48%, 33%, and 33%, to amikacin, kanamycin and gentamicin were 19%, 24% and 38%, to cotrimoxazole and erythromycin were 48% and 15%, to florfenicol, chloramphenicol and polymyxin B were 29%, 33%, and 5%. Nine strains of pathogenic calf diarrhea Escherichia coli were isolated by mouse pathogenicity test. The detection rates of virulence genes for the adhesion class were fimC (95%), IuxS (95%), eaeA (76%), fimA (62%), ompA (52%), and flu (24%). The detection rates for iron transporter protein like virulence genes were iroN (33%), iutA (19%), fyuA (14%), irp5 (9.5%), Iss (9.5%), and iucD (9.5%). The detection rates for toxin-like virulence genes were phoA (90%), Ecs3703 (57%), ropS (33%), hlyF (14%), and F17 (9.5%). The detection rates of tetracycline resistance genes in isolated strains were tetB (29%), tetA (19%) and tetD (14%). The detection rates for fluoroquinolone resistance genes were parC (Y305H, P333S, R355G) (9.5%), gyrA (S83L, D87N) (28%), qnrD (43%), and qnrS (9.5%). The detection rates for β-lactam resistance genes were bla CTX-M (29%), bla TEM (29%), and bla SHV (9.5%). The detection rates for aminoglycoside resistance genes were strA-B (57%), aacC (33%), aac(3')-IIa (29%), and aadAI (24%). The detection rates of chloramphenicol resistance genes floR and sulfa resistance genes sul2 were 24 and 33%. Conclusion Pathogenic Escherichia coli causing diarrhea in calves contain abundant virulence genes and antibiotic resistance genes.
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Affiliation(s)
- Yan Jia
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China,Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Hohhot, China,Xuzhou Vocational College of Bioengineering, Xuzhou, Jiangsu, China
| | - Wei Mao
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China,Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Hohhot, China
| | - Bo Liu
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China,Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Hohhot, China
| | - Shuangyi Zhang
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China,Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Hohhot, China
| | - Jinshan Cao
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China,Key Laboratory of Animal Clinical Treatment Technology, Ministry of Agriculture, Hohhot, China,Jinshan Cao,
| | - Xiaojing Xu
- College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China,*Correspondence: Xiaojing Xu,
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Huang Y, Geng H, Wu Z, Sun L, Ji C, Grimes CA, Feng X, Cai Q. An Ag 2S@ZIF-Van nanosystem for NIR-II imaging of bacterial-induced inflammation and treatment of wound bacterial infection. Biomater Sci 2022; 10:3972-3980. [PMID: 35708482 DOI: 10.1039/d2bm00550f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bacterial diseases pose a serious threat to human health. Continued development of precise diagnostic methods and synergistic therapy techniques for combating bacteria are needed. Herein a hybrid nanosystem (Ag2S@ZIF-Van NS) was constructed by one-step self-assembly of Zn2+, vancomycin (Van) and Ag2S quantum dots (QDs). The nanosystem possesses excellent second near-infrared transparency window (NIR-II) fluorescence properties (∼1200 nm emission wavelength), good photothermal conversion properties, and biocompatibility. The material system enables precise, targeted NIR-II fluorescent imaging of bacterial inflammation in vivo as well as promoting anti-bacterial and wound healing effects.
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Affiliation(s)
- Yao Huang
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
| | - Hongchao Geng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
| | - Zeming Wu
- Inner Mongolia Environmental Monitoring Center, Hohhot 010011, Inner Mongolia, China
| | - Leilei Sun
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
| | - Chenhui Ji
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
| | | | - Xinxin Feng
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
| | - Qingyun Cai
- State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, Hunan, China.
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Activation of the Type III Secretion System of Enteropathogenic Escherichia coli Leads to Remodeling of Its Membrane Composition and Function. mSystems 2022; 7:e0020222. [PMID: 35477304 PMCID: PMC9238428 DOI: 10.1128/msystems.00202-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The cell envelope of Gram-negative bacteria is a complex structure, essential for bacterial survival and for resistance to many antibiotics. Channels that cross the bacterial envelope and the host cell membrane form secretion systems that are activated upon attachment to host, enabling bacteria to inject effector molecules into the host cell, required for bacterium-host interaction. The type III secretion system (T3SS) is critical for the virulence of several pathogenic bacteria, including enteropathogenic Escherichia coli (EPEC). EPEC T3SS activation is associated with repression of carbon storage regulator (CsrA), resulting in gene expression remodeling, which is known to affect EPEC central carbon metabolism and contributes to the adaptation to a cell-adherent lifestyle in a poorly understood manner. We reasoned that the changes in the bacterial envelope upon attachment to the host and the activation of a secretion system may involve a modification of the lipid composition of bacterial envelope. Accordingly, we performed a lipidomics analysis on mutant strains that simulate T3SS activation. We saw a shift in glycerophospholipid metabolism toward the formation of lysophospholipids, attributed to corresponding upregulation of the phospholipase gene pldA and the acyltransferase gene ygiH upon T3SS activation in EPEC. We also detected a shift from menaquinones and ubiquinones to undecaprenyl lipids, concomitant with abnormal synthesis of O antigen. The remodeling of lipid metabolism is mediated by CsrA and associated with increased bacterial cell size and zeta potential and a corresponding alteration in EPEC permeability to vancomycin, increasing the sensitivity of T3SS-activated strains and of adherent wild-type EPEC to the antibiotic. IMPORTANCE The characterization of EPEC membrane lipid metabolism upon attachment to the host is an important step toward a better understanding the shift of EPEC, a notable human pathogen, from a planktonic to adherent lifestyle. It may also apply to other pathogenic bacteria that use this secretion system. We predict that upon attachment to host cells, the lipid remodeling upon T3SS activation contributes to bacterial fitness and promotes host colonization, and we show that it is associated with increased cell permeability and higher sensitivity to vancomycin. To the best of our knowledge, this is the first demonstration of a bacterial lipid remodeling due to activation of a secretion system.
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Zhong Q, Chatterjee S, Choudhary JS, Frankel G. EPEC-induced activation of the Ca 2+ transporter TRPV2 leads to pyroptotic cell death. Mol Microbiol 2022; 117:480-492. [PMID: 34897856 DOI: 10.1111/mmi.14863] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/27/2022]
Abstract
The enteropathogenic Escherichia coli (EPEC) type III secretion system effector Tir, which mediates intimate bacterial attachment to epithelial cells, also triggers Ca2+ influx followed by LPS entry and caspase-4-dependent pyroptosis, which could be antagonized by the effector NleF. Here we reveal the mechanism by which EPEC induces Ca2+ influx. We show that in the intestinal epithelial cell line SNU-C5, Tir activates the mechano/osmosensitive cation channel TRPV2 which triggers extracellular Ca2+ influx. Tir-induced Ca2+ influx could be blocked by siRNA silencing of TRPV2, pre-treatment with the TRPV2 inhibitor SET2 or by growing cells in low osmolality medium. Pharmacological activation of TRPV2 in the absence of Tir failed to initiate caspase-4-dependent cell death, confirming the necessity of Tir. Consistent with the model implicating activation on translocation of TRPV2 from the ER to plasma membrane, inhibition of protein trafficking by either brefeldin A or the effector NleA prevented TRPV2 activation and cell death. While infection with EPECΔnleA triggered pyroptotic cell death, this could be prevented by NleF. Taken together this study shows that while integration of Tir into the plasma membrane activates TRPV2, EPEC uses NleA to inhibit TRPV2 trafficking and NleF to inhibit caspase-4 and pyroptosis.
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Affiliation(s)
- Qiyun Zhong
- Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Sharanya Chatterjee
- Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Jyoti S Choudhary
- Functional Proteomics Group, Chester Beatty Laboratories, The Institute of Cancer Research, London, UK
| | - Gad Frankel
- Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College, London, UK
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Skåne A, Loose JSM, Vaaje-Kolstad G, Askarian F. Comparative proteomic profiling reveals specific adaption of Vibrio anguillarum to oxidative stress, iron deprivation and humoral components of innate immunity. J Proteomics 2022; 251:104412. [PMID: 34737109 DOI: 10.1016/j.jprot.2021.104412] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/05/2021] [Accepted: 10/13/2021] [Indexed: 12/25/2022]
Abstract
The gram-negative bacterium Vibrio (Listonella) anguillarum (VA) is the causative agent of vibriosis, a terminal hemorrhagic septicemia affecting the aquacultural industry across the globe. In the current study we used label-free quantitative proteomics to investigate how VA adapts to conditions that mimic defined aspects of vibriosis-related stress such as exposure to oxidative stress (H2O2), exposure to humoral factors of innate immunity through incubation with Atlantic salmon serum, and iron deprivation upon supplementation of 2,2'-dipyridyl (DIP) to the growth medium. We also investigated how regulation of virulence factors may be governed by the VA growth phase and availability of nutrients. All experimental conditions explored revealed stress-specific proteomic adaption of VA and only nine proteins were found to be commonly regulated in all conditions. A general observation made for all stress-related conditions was regulation of multiple metabolic pathways. Notably, iron deprivation and exposure to Atlantic salmon serum evoked upregulation of iron acquisition mechanisms. The findings made in the present study represent a source of potential virulence determinants that can be of use in the search for means to understand vibriosis. SIGNIFICANCE: Vibriosis in fish and shellfish caused by V. anguillarum (VA) is responsible for large economic losses in the aquaculture sector across the globe. However, not much is known about the defense mechanism of this pathogen to percept and adapt to the imposed stresses during infection. Analyzing the response of VA to multiple host-related physiochemical stresses, the quantitative proteomic analysis of the present study indicates modulation of several virulence determinants and key defense networks of this pathogen. Our findings provide a theoretical basis to enhance our understanding of VA pathogenesis and can be employed to improve current intervention strategies to control vibriosis in aquaculture.
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Affiliation(s)
- Anna Skåne
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Jennifer S M Loose
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway.
| | - Fatemeh Askarian
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), Ås, Norway; Department of Pediatrics, University of California San Diego, La Jolla, CA 92093, USA.
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Attachment of Enterohemorrhagic Escherichia coli to Host Cells Reduces O Antigen Chain Length at the Infection Site That Promotes Infection. mBio 2021; 12:e0269221. [PMID: 34903041 PMCID: PMC8669466 DOI: 10.1128/mbio.02692-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many enteropathogenic bacteria express a needle-like type III secretion system (T3SS) that translocates effectors into host cells promoting infection. O antigen (OAg) constitutes the outer layer of Gram-negative bacteria protecting bacteria from host immune responses. Shigella constitutively shortens the OAg molecule in its three-dimensional conformation by glucosylation, leading to enhanced T3SS function. However, whether and how other enteropathogenic bacteria shorten the OAg molecule that probably facilitates infection remain unknown. For the first time, we report a smart mechanism by which enterohemorrhagic Escherichia coli specifically reduces the size of the OAg molecule at the infection site upon sensing mechanical signals of intestinal epithelial cell attachment via the membrane protein YgjI. YgjI represses expression of the OAg chain length regulator gene fepE via the global regulator H-NS, leading to shortened OAg chains and injection of more T3SS effectors into host cells. However, bacteria express long-chain OAg in the intestinal lumen benefiting their survival. Animal experiments show that blocking this regulatory pathway significantly attenuates bacterial virulence. This finding enhances our understanding of interactions between the surfaces of bacterial and host cells and the way this interaction enhances bacterial pathogenesis. IMPORTANCE Little is known about the regulation of cell wall structure of enteropathogenic bacteria within the host. Here, we report that enterohemorrhagic Escherichia coli regulates its cell wall structure during the infection process, which balances its survival in the intestinal lumen and infection of intestinal epithelial cells. In the intestinal lumen, bacteria express long-chain OAg, which is located in the outer part of the cell wall, leading to enhanced resistance to antimicrobial peptides. However, upon epithelial cell attachment, bacteria sense this mechanical signal via a membrane protein and reduce the OAg chain length, resulting in enhanced injection into epithelial cells of T3SS effectors that mediate host cell infection. Similar regulation mechanisms of cell wall structure in response to host cell attachment may be widespread in pathogenic bacteria and closely related with bacterial pathogenesis.
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Yin L, Li Q, Wang Z, Shen X, Tu J, Shao Y, Song X, Qi K, Pan X. The Escherichia coli type III secretion system 2 Is involved in the biofilm formation and virulence of avian Pathogenic Escherichia coli. Comp Immunol Microbiol Infect Dis 2021; 79:101722. [PMID: 34823134 DOI: 10.1016/j.cimid.2021.101722] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 10/26/2021] [Accepted: 11/09/2021] [Indexed: 12/13/2022]
Abstract
The Escherichia coli type III secretion system 2 (ETT2) is found in most pathogenic E. coli strains. Although many ETT2 gene clusters carry multiple genetic mutations or deletions, ETT2 is known to be involved in bacterial virulence. To date, no studies have been conducted on the role of ETT2 in the virulence of avian pathogenic Escherichia coli (APEC), which harbours ETT2. Thus, we deleted the ETT2 of APEC strain and evaluated the phenotypes and pathogenicities of the mutant. The results showed that deletion of ETT2 had no effect on APEC growth, but significantly promoted biofilm formation. In addition, as compared to the wild-type (WT) strain, the ETT2 deletion significantly promoted adherence to and invasion of DF-1 chicken fibroblasts and facilitated survival in the sera of specific-pathogen-free chickens. Analysis of the role of ETT2 in animal infection models demonstrated that the distribution of viable bacteria in the blood and organs of chicks infected with the ΔETT2 was significantly higher than those infected with WT. The results of RNA sequencing indicated that multiple genes involved in biofilm formation, lipopolysaccharide components, fimbrial genes and virulence effector proteins are regulated by ETT2. Collectively, these results implicated ETT2 is involved in the biofilm formation and pathogenicity of APEC.
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Affiliation(s)
- Lei Yin
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China; Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui 230031, China
| | - Qianwen Li
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Zeping Wang
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Xuehuai Shen
- Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui 230031, China
| | - Jian Tu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Ying Shao
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Xiangjun Song
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China.
| | - Xiaocheng Pan
- Livestock and Poultry Epidemic Diseases Research Center of Anhui Province, Institute of Animal Husbandry and Veterinary Science, Anhui Academy of Agricultural Sciences, Hefei, Anhui 230031, China.
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Zhang Y, Andrade MO, Wang W, Teper D, Romeo T, Wang N. Examination of the Global Regulon of CsrA in Xanthomonas citri subsp. citri Using Quantitative Proteomics and Other Approaches. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2021; 34:1236-1249. [PMID: 34282945 DOI: 10.1094/mpmi-05-21-0113-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The RNA-binding protein CsrA is a global posttranscriptional regulator and controls many physiological processes and virulence traits. Deletion of csrA caused loss of virulence, reduced motility and production of xanthan gum and substantial increase in glycogen accumulation, as well as enhanced bacterial aggregation and cell adhesion in Xanthomonas spp. How CsrA controls these traits is poorly understood. In this study, an isobaric tag for relative and absolute quantitation (iTRAQ)-based proteomic analysis was conducted to compare the protein profile of wild-type strain Xanthomonas citri subsp. citri and the isogenic ΔcsrA strain. A total of 2,374 proteins were identified, and 284 were considered to be differentially expressed proteins (DEPS), among which 151 proteins were up-regulated and 133 were down-regulated in the ΔcsrA strain with respect to the wild-type strain. Enrichment analysis and a protein-protein interaction network analysis showed that CsrA regulates bacterial secretion systems, flagella, and xanthan gum biosynthesis. Several proteins encoded by the gumB operon were down-regulated, whereas proteins associated with flagellum assembly and the type IV secretion system were up-regulated in the ΔcsrA strain relative to the Xcc306 strain. These results were confirmed by β-glucuronidase assay or Western blot. RNA secondary structure prediction and a gel-shift assay indicated that CsrA binds to the Shine-Dalgarno sequence of virB5. In addition, the iTRAQ analysis identified 248 DEPs that were not previously identified in transcriptome analyses. Among them, CsrA regulates levels of eight regulatory proteins (ColR, GacA, GlpR, KdgR, MoxR, PilH, RecX, and YgiX), seven TonB-dependent receptors, four outer membrane proteins, and two ferric enterobactin receptors. Taken together, this study greatly expands understanding of the regulatory network of CsrA in X. citri subsp. citri.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Yanan Zhang
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred FL 33850, U.S.A
- Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan, 655011, China
| | - Maxuel O Andrade
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred FL 33850, U.S.A
- Brazilian Biorenewables National Laboratory (LNBR), Brazilian Centre for Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Wenting Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred FL 33850, U.S.A
- Department of Plant Pathology, University of Florida, Gainesville FL 32611, U.S.A
| | - Doron Teper
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred FL 33850, U.S.A
| | - Tony Romeo
- Department of Microbiology and Cell Sciences, University of Florida, Gainesville FL 32611, U.S.A
| | - Nian Wang
- Citrus Research and Education Center, Department of Microbiology and Cell Sciences, University of Florida, 700 Experiment Station Road, Lake Alfred FL 33850, U.S.A
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14
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Pearl Mizrahi S, Elbaz N, Argaman L, Altuvia Y, Katsowich N, Socol Y, Bar A, Rosenshine I, Margalit H. The impact of Hfq-mediated sRNA-mRNA interactome on the virulence of enteropathogenic Escherichia coli. SCIENCE ADVANCES 2021; 7:eabi8228. [PMID: 34705501 PMCID: PMC8550237 DOI: 10.1126/sciadv.abi8228] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Small RNAs (sRNAs) exert their regulation posttranscriptionally by base pairing with their target mRNAs, often in association with the RNA chaperone protein Hfq. Here, integrating RNA-seq–based technologies and bioinformatics, we deciphered the Hfq-mediated sRNA-target interactome of enteropathogenic Escherichia coli (EPEC). The emerging network comprises hundreds of sRNA-mRNA pairs, including mRNAs of virulence-associated genes interacting with known sRNAs encoded within the core genome, as well as with newly found sRNAs encoded within pathogenicity islands. Some of the sRNAs affect multiple virulence genes, suggesting they function as hubs of virulence control. We further analyzed one such sRNA hub, MgrR, and one of its targets identified here, the major virulence-associated chaperon, cesT. We show that MgrR adjusts the level of EPEC cytotoxicity via regulation of CesT expression. Our results reveal an elaborate sRNA-mRNA interactome controlling the pathogenicity of EPEC and reinforce a role for sRNAs in the control of pathogen-host interaction.
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Affiliation(s)
- Sivan Pearl Mizrahi
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Netanel Elbaz
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Liron Argaman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Yael Altuvia
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Naama Katsowich
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Yaakov Socol
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Amir Bar
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
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15
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Smallets S, Kendall MM. Post-transcriptional regulation in attaching and effacing pathogens: integration of environmental cues and the impact on gene expression and host interactions. Curr Opin Microbiol 2021; 63:238-243. [PMID: 34450388 DOI: 10.1016/j.mib.2021.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/04/2021] [Indexed: 11/25/2022]
Abstract
To establish infection, enteric pathogens integrate environmental cues to navigate the gastrointestinal tract and precisely control expression of virulence determinants. Emerging data indicate that post-transcriptional and post-translational gene regulation plays a key role in virulence regulation and pathogen adaptation to the host environment. Here, we highlight recent studies that reveal how physiologically relevant signals initiate post-transcriptional and post-translational regulatory circuits and the impact on virulence gene expression in the attaching and effacing pathogens, enteropathogenic Escherichia coli, enterohemorrhagic E. coli O157:H7, and Citrobacter rodentium.
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Affiliation(s)
- Sarah Smallets
- Department of Biology, University of Virginia, 485 McCormick Rd., Charlottesville, VA, 22904, USA
| | - Melissa M Kendall
- Department of Microbiology, Immunology, and Cancer Biology, University of Virginia School of Medicine, 1340 Jefferson Park Ave., Charlottesville, VA, 22908, USA.
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16
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Manera K, Kamal F, Burkinshaw B, Dong TG. Essential functions of chaperones and adaptors of protein secretion systems in Gram-negative bacteria. FEBS J 2021; 289:4704-4717. [PMID: 34092034 DOI: 10.1111/febs.16056] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 05/18/2021] [Accepted: 06/04/2021] [Indexed: 01/02/2023]
Abstract
Equipped with a plethora of secreted toxic effectors, protein secretion systems are essential for bacteria to interact with and manipulate their neighboring environment to survive in host microbiota and other highly competitive communities. While effectors have received spotlight attention in secretion system studies, many require accessory chaperone and adaptor proteins for proper folding/unfolding and stability throughout the secretion process. Here, we review the functions of chaperones and adaptors of three protein secretions systems, type 3 secretion system (T3SS), type 4 secretion system (T4SS), and type 6 secretion system (T6SS), which are employed by many Gram-negative bacterial pathogens to deliver toxins to bacterial, plant, and mammalian host cells through direct contact. Since chaperone and adaptor functions of the T3SS and the T4SS are relatively well studied, we discuss in detail the methods of chaperone-facilitated effector secretion by the T6SS and highlight commonalities between the effector chaperone/adaptor proteins of these diverse secretion systems. While the chaperones and adaptors are generally referred to as accessory proteins as they are not directly involved in toxicities to target cells, they are nonetheless vital for the biological functions of the secretion systems. Future research on biochemical and structural properties of these chaperones will not only elucidate the mechanisms of chaperone-effector binding and release process but also facilitate custom design of cargo effectors to be translocated by these widespread secretion systems for biotechnological applications.
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Affiliation(s)
- Kevin Manera
- Department of Ecosystem and Public Health, University of Calgary, Canada
| | - Fatima Kamal
- Department of Ecosystem and Public Health, University of Calgary, Canada
| | | | - Tao G Dong
- Department of Ecosystem and Public Health, University of Calgary, Canada.,State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic & Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, China
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17
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Gerovac M, Vogel J, Smirnov A. The World of Stable Ribonucleoproteins and Its Mapping With Grad-Seq and Related Approaches. Front Mol Biosci 2021; 8:661448. [PMID: 33898526 PMCID: PMC8058203 DOI: 10.3389/fmolb.2021.661448] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/04/2021] [Indexed: 12/13/2022] Open
Abstract
Macromolecular complexes of proteins and RNAs are essential building blocks of cells. These stable supramolecular particles can be viewed as minimal biochemical units whose structural organization, i.e., the way the RNA and the protein interact with each other, is directly linked to their biological function. Whether those are dynamic regulatory ribonucleoproteins (RNPs) or integrated molecular machines involved in gene expression, the comprehensive knowledge of these units is critical to our understanding of key molecular mechanisms and cell physiology phenomena. Such is the goal of diverse complexomic approaches and in particular of the recently developed gradient profiling by sequencing (Grad-seq). By separating cellular protein and RNA complexes on a density gradient and quantifying their distributions genome-wide by mass spectrometry and deep sequencing, Grad-seq charts global landscapes of native macromolecular assemblies. In this review, we propose a function-based ontology of stable RNPs and discuss how Grad-seq and related approaches transformed our perspective of bacterial and eukaryotic ribonucleoproteins by guiding the discovery of new RNA-binding proteins and unusual classes of noncoding RNAs. We highlight some methodological aspects and developments that permit to further boost the power of this technique and to look for exciting new biology in understudied and challenging biological models.
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Affiliation(s)
- Milan Gerovac
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany
| | - Jörg Vogel
- Institute of Molecular Infection Biology (IMIB), University of Würzburg, Würzburg, Germany
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Alexandre Smirnov
- UMR 7156—Génétique Moléculaire, Génomique, Microbiologie (GMGM), University of Strasbourg, CNRS, Strasbourg, France
- University of Strasbourg Institute for Advanced Study (USIAS), Strasbourg, France
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18
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Xing Z, Li H, Li M, Gao R, Guo C, Mi S. Disequilibrium in chicken gut microflora with avian colibacillosis is related to microenvironment damaged by antibiotics. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143058. [PMID: 33127154 DOI: 10.1016/j.scitotenv.2020.143058] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/25/2020] [Accepted: 10/10/2020] [Indexed: 06/11/2023]
Abstract
The avian colibacillosis outbreak is a disease that threatens public health, poultry production, and economic interests, even after antibiotic feed addition. It is known that avian pathogenic E. coli is a major pathogenic factor; however, the systemic characteristics of gut flora in disease samples and how pathogens grow remain unknown. To study these issues in depth, we used the whole microbial genome shotgun sequencing technique to compare entire microbes in diseased and healthy broiler chickens. We found that it was not only E. coli that increased substantially, but most pathogenic flora also increased significantly in diseased samples. Subsequently, we proved that aminoglycoside antibiotic resistance genes were mainly found in non-E. coli strains. This suggests that E. coli survival under antibiotic stress was due to the cooperative resistance from non-E. coli strains. Among all these increasing strains, attaching and effacing pathogens could damage host intestinal epithelial cells to release oxygen in the gut to make the microenvironment more adaptable for E. coli strains. Furthermore, we observed that the functions of the T4SS/T6SS secretion system were dramatically enhanced, which could help E. coli to compete and enlarge their living spaces. Ultimately, pathogenic E. coli accumulated to cause avian colibacillosis. This study provides a new insight into intestinal microecology in diseased individuals, which would propose new treatment options for avian colibacillosis from a metagenome perspective.
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Affiliation(s)
- Zhikai Xing
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Hui Li
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Meng Li
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China
| | - Ran Gao
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China
| | - Chongye Guo
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China.
| | - Shuangli Mi
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, China National Center for Bioinformation, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
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19
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Ruano-Gallego D, Sanchez-Garrido J, Kozik Z, Núñez-Berrueco E, Cepeda-Molero M, Mullineaux-Sanders C, Naemi Baghshomali Y, Slater SL, Wagner N, Glegola-Madejska I, Roumeliotis TI, Pupko T, Fernández LÁ, Rodríguez-Patón A, Choudhary JS, Frankel G. Type III secretion system effectors form robust and flexible intracellular virulence networks. Science 2021; 371:eabc9531. [PMID: 33707240 DOI: 10.1126/science.abc9531] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/15/2020] [Accepted: 01/15/2021] [Indexed: 12/14/2022]
Abstract
Infections with many Gram-negative pathogens, including Escherichia coli, Salmonella, Shigella, and Yersinia, rely on type III secretion system (T3SS) effectors. We hypothesized that while hijacking processes within mammalian cells, the effectors operate as a robust network that can tolerate substantial contractions. This was tested in vivo using the mouse pathogen Citrobacter rodentium (encoding 31 effectors). Sequential gene deletions showed that effector essentiality for infection was context dependent and that the network could tolerate 60% contraction while maintaining pathogenicity. Despite inducing very different colonic cytokine profiles (e.g., interleukin-22, interleukin-17, interferon-γ, or granulocyte-macrophage colony-stimulating factor), different networks induced protective immunity. Using data from >100 distinct mutant combinations, we built and trained a machine learning model able to predict colonization outcomes, which were confirmed experimentally. Furthermore, reproducing the human-restricted enteropathogenic E. coli effector repertoire in C. rodentium was not sufficient for efficient colonization, which implicates effector networks in host adaptation. These results unveil the extreme robustness of both T3SS effector networks and host responses.
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Affiliation(s)
- David Ruano-Gallego
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Julia Sanchez-Garrido
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Zuzanna Kozik
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Elena Núñez-Berrueco
- Laboratorio de Inteligencia Artificial, Departamento de Inteligencia Artificial, Universidad Politécnica de Madrid, Campus de Montegancedo, Boadilla del Monte, Madrid, Spain
| | - Massiel Cepeda-Molero
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | | | - Yasaman Naemi Baghshomali
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Sabrina L Slater
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Naama Wagner
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Izabela Glegola-Madejska
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK
| | - Theodoros I Roumeliotis
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK
| | - Tal Pupko
- The Shmunis School of Biomedicine and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Luis Ángel Fernández
- Centro Nacional de Biotecnología (CNB-CSIC), Department of Microbial Biotechnology, Madrid, Spain
| | - Alfonso Rodríguez-Patón
- Laboratorio de Inteligencia Artificial, Departamento de Inteligencia Artificial, Universidad Politécnica de Madrid, Campus de Montegancedo, Boadilla del Monte, Madrid, Spain
| | - Jyoti S Choudhary
- Functional Proteomics Group, Chester Beatty Laboratories, Institute of Cancer Research, London, UK.
| | - Gad Frankel
- Centre for Molecular Microbiology and Infection, Department of Life Sciences, Imperial College, London, UK.
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20
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Pimenta AI, Bernardes N, Alves MM, Mil-Homens D, Fialho AM. Burkholderia cenocepacia transcriptome during the early contacts with giant plasma membrane vesicles derived from live bronchial epithelial cells. Sci Rep 2021; 11:5624. [PMID: 33707642 PMCID: PMC7970998 DOI: 10.1038/s41598-021-85222-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023] Open
Abstract
Burkholderia cenocepacia is known for its capacity of adherence and interaction with the host, causing severe opportunistic lung infections in cystic fibrosis patients. In this work we produced Giant Plasma Membrane Vesicles (GPMVs) from a bronchial epithelial cell line and validated their use as a cell-like alternative to investigate the steps involved in the adhesion process of B. cenocepacia. RNA-sequencing was performed and the analysis of the B. cenocepacia K56-2 transcriptome after the first contacts with the surface of host cells allowed the recognition of genes implicated in bacterial adaptation and virulence-associated functions. The sensing of host membranes led to a transcriptional shift that caused a cascade of metabolic and physiological adaptations to the host specific environment. Many of the differentially expressed genes encode proteins related with central metabolic pathways, transport systems, cellular processes, and virulence traits. The understanding of the changes in gene expression that occur in the early steps of infection can uncover new proteins implicated in B. cenocepacia-host cell adhesion, against which new blocking agents could be designed to control the progression of the infectious process.
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Affiliation(s)
- Andreia I. Pimenta
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Nuno Bernardes
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Marta M. Alves
- grid.9983.b0000 0001 2181 4263CQE Instituto Superior Técnico, Departamento de Engenharia Química, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
| | - Dalila Mil-Homens
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
| | - Arsenio M. Fialho
- iBB-Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal ,grid.9983.b0000 0001 2181 4263Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
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21
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Sy BM, Tree JJ. Small RNA Regulation of Virulence in Pathogenic Escherichia coli. Front Cell Infect Microbiol 2021; 10:622202. [PMID: 33585289 PMCID: PMC7873438 DOI: 10.3389/fcimb.2020.622202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/10/2020] [Indexed: 11/17/2022] Open
Abstract
Enteric and extraintestinal pathotypes of Escherichia coli utilize a wide range of virulence factors to colonize niches within the human body. During infection, virulence factors such as adhesins, secretions systems, or toxins require precise regulation and coordination to ensure appropriate expression. Additionally, the bacteria navigate rapidly changing environments with fluctuations in pH, temperature, and nutrient levels. Enteric pathogens utilize sophisticated, interleaved systems of transcriptional and post-transcriptional regulation to sense and respond to these changes and modulate virulence gene expression. Regulatory small RNAs and RNA-binding proteins play critical roles in the post-transcriptional regulation of virulence. In this review we discuss how the mosaic genomes of Escherichia coli pathotypes utilize small RNA regulation to adapt to their niche and become successful human pathogens.
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Affiliation(s)
- Brandon M Sy
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
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22
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Irastortza-Olaziregi M, Amster-Choder O. Coupled Transcription-Translation in Prokaryotes: An Old Couple With New Surprises. Front Microbiol 2021; 11:624830. [PMID: 33552035 PMCID: PMC7858274 DOI: 10.3389/fmicb.2020.624830] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 12/18/2020] [Indexed: 01/17/2023] Open
Abstract
Coupled transcription-translation (CTT) is a hallmark of prokaryotic gene expression. CTT occurs when ribosomes associate with and initiate translation of mRNAs whose transcription has not yet concluded, therefore forming "RNAP.mRNA.ribosome" complexes. CTT is a well-documented phenomenon that is involved in important gene regulation processes, such as attenuation and operon polarity. Despite the progress in our understanding of the cellular signals that coordinate CTT, certain aspects of its molecular architecture remain controversial. Additionally, new information on the spatial segregation between the transcriptional and the translational machineries in certain species, and on the capability of certain mRNAs to localize translation-independently, questions the unanimous occurrence of CTT. Furthermore, studies where transcription and translation were artificially uncoupled showed that transcription elongation can proceed in a translation-independent manner. Here, we review studies supporting the occurrence of CTT and findings questioning its extent, as well as discuss mechanisms that may explain both coupling and uncoupling, e.g., chromosome relocation and the involvement of cis- or trans-acting elements, such as small RNAs and RNA-binding proteins. These mechanisms impact RNA localization, stability, and translation. Understanding the two options by which genes can be expressed and their consequences should shed light on a new layer of control of bacterial transcripts fate.
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Affiliation(s)
- Mikel Irastortza-Olaziregi
- Department of Microbiology and Molecular Genetics, Faculty of Medicine, IMRIC, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Orna Amster-Choder
- Department of Microbiology and Molecular Genetics, Faculty of Medicine, IMRIC, The Hebrew University of Jerusalem, Jerusalem, Israel
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23
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Bogacz M, El Abbar FM, Cox CA, Li J, Fiedler JS, Tran LKH, Tran PMH, Daugherty CL, Blake KH, Wang Z, Azadi P, Thompson SA. Binding of Campylobacter jejuni FliW Adjacent to the CsrA RNA-Binding Pockets Modulates CsrA Regulatory Activity. Front Microbiol 2021; 11:531596. [PMID: 33505360 PMCID: PMC7829508 DOI: 10.3389/fmicb.2020.531596] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 12/08/2020] [Indexed: 11/13/2022] Open
Abstract
Campylobacter jejuni CsrA is an mRNA-binding, post-transcriptional regulator that controls many metabolic- and virulence-related characteristics of this important pathogen. In contrast to E. coli CsrA, whose activity is modulated by binding to small non-coding RNAs (sRNAs), C. jejuni CsrA activity is controlled by binding to the CsrA antagonist FliW. In this study, we identified the FliW binding site on CsrA. Deletion of the C-terminus of C. jejuni CsrA, which is extended relative to sRNA-binding CsrA proteins, abrogated FliW binding. Bacterial two-hybrid experiments were used to assess the interaction of FliW with wild-type CsrA and mutants thereof, in which every amino acid was individually mutated. Two CsrA mutations (V51A and N55A) resulted in a significant decrease in FliW binding. The V51A and N55A mutants also showed a decrease in CsrA-FliW complex formation, as assessed by size-exclusion chromatography and surface plasmon resonance. These residues were highly conserved in bacterial species containing CsrA orthologs whose activities are predicted to be regulated by FliW. The location of FliW binding was immediately adjacent to the two RNA-binding sites of the CsrA homodimer, suggesting the model that FliW binding to CsrA modulates its ability to bind to its mRNA targets either by steric hindrance, electrostatic repulsion, or by altering the overall structure of the RNA-binding sites.
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Affiliation(s)
- Marek Bogacz
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Faiha M El Abbar
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Claudia A Cox
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jiaqi Li
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jarred S Fiedler
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Lynn K H Tran
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Paul M H Tran
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - C Luke Daugherty
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Kate H Blake
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Zhirui Wang
- Complex Carbohydrate Research Center, The University of Georgia, Athens, GA, United States
| | - Parastoo Azadi
- Complex Carbohydrate Research Center, The University of Georgia, Athens, GA, United States
| | - Stuart A Thompson
- Division of Infectious Diseases, Department of Medicine, Medical College of Georgia, Augusta University, Augusta, GA, United States
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24
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Bajunaid W, Haidar-Ahmad N, Kottarampatel AH, Ourida Manigat F, Silué N, F. Tchagang C, Tomaro K, Campbell-Valois FX. The T3SS of Shigella: Expression, Structure, Function, and Role in Vacuole Escape. Microorganisms 2020; 8:microorganisms8121933. [PMID: 33291504 PMCID: PMC7762205 DOI: 10.3390/microorganisms8121933] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/01/2020] [Accepted: 12/03/2020] [Indexed: 12/18/2022] Open
Abstract
Shigella spp. are one of the leading causes of infectious diarrheal diseases. They are Escherichia coli pathovars that are characterized by the harboring of a large plasmid that encodes most virulence genes, including a type III secretion system (T3SS). The archetypal element of the T3SS is the injectisome, a syringe-like nanomachine composed of approximately 20 proteins, spanning both bacterial membranes and the cell wall, and topped with a needle. Upon contact of the tip of the needle with the plasma membrane, the injectisome secretes its protein substrates into host cells. Some of these substrates act as translocators or effectors whose functions are key to the invasion of the cytosol and the cell-to-cell spread characterizing the lifestyle of Shigella spp. Here, we review the structure, assembly, function, and methods to measure the activity of the injectisome with a focus on Shigella, but complemented with data from other T3SS if required. We also present the regulatory cascade that controls the expression of T3SS genes in Shigella. Finally, we describe the function of translocators and effectors during cell-to-cell spread, particularly during escape from the vacuole, a key element of Shigella’s pathogenesis that has yet to reveal all of its secrets.
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Affiliation(s)
- Waad Bajunaid
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Nathaline Haidar-Ahmad
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Anwer Hasil Kottarampatel
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - France Ourida Manigat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Navoun Silué
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Caetanie F. Tchagang
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Kyle Tomaro
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - François-Xavier Campbell-Valois
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (W.B.); (N.H.-A.); (A.H.K.); (F.O.M.); (N.S.); (C.F.T.); (K.T.)
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Correspondence:
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25
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Pourciau C, Lai YJ, Gorelik M, Babitzke P, Romeo T. Diverse Mechanisms and Circuitry for Global Regulation by the RNA-Binding Protein CsrA. Front Microbiol 2020; 11:601352. [PMID: 33193284 PMCID: PMC7652899 DOI: 10.3389/fmicb.2020.601352] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
The carbon storage regulator (Csr) or repressor of stationary phase metabolites (Rsm) system of Gammaproteobacteria is among the most complex and best-studied posttranscriptional regulatory systems. Based on a small RNA-binding protein, CsrA and homologs, it controls metabolism, physiology, and bacterial lifestyle decisions by regulating gene expression on a vast scale. Binding of CsrA to sequences containing conserved GGA motifs in mRNAs can regulate translation, RNA stability, riboswitch function, and transcript elongation. CsrA governs the expression of dozens of transcription factors and other regulators, further expanding its influence on cellular physiology, and these factors can participate in feedback to the Csr system. Expression of csrA itself is subject to autoregulation via translational inhibition and indirect transcriptional activation. CsrA activity is controlled by small noncoding RNAs (sRNAs), CsrB and CsrC in Escherichia coli, which contain multiple high affinity CsrA binding sites that compete with those of mRNA targets. Transcription of CsrB/C is induced by certain nutrient limitations, cellular stresses, and metabolites, while these RNAs are targeted for degradation by the presence of a preferred carbon source. Consistent with these findings, CsrA tends to activate pathways and processes that are associated with robust growth and repress stationary phase metabolism and stress responses. Regulatory loops between Csr components affect the signaling dynamics of the Csr system. Recently, systems-based approaches have greatly expanded our understanding of the roles played by CsrA, while reinforcing the notion that much remains to be learned about the Csr system.
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Affiliation(s)
- Christine Pourciau
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Ying-Jung Lai
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Mark Gorelik
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, United States
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States
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26
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Slater SL, Frankel G. Advances and Challenges in Studying Type III Secretion Effectors of Attaching and Effacing Pathogens. Front Cell Infect Microbiol 2020; 10:337. [PMID: 32733819 PMCID: PMC7358347 DOI: 10.3389/fcimb.2020.00337] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/04/2020] [Indexed: 12/24/2022] Open
Affiliation(s)
- Sabrina L Slater
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, United Kingdom
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27
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Pimenta AI, Mil‐Homens D, Fialho AM. Burkholderia cenocepacia-host cell contact controls the transcription activity of the trimeric autotransporter adhesin BCAM2418 gene. Microbiologyopen 2020; 9:e998. [PMID: 32097539 PMCID: PMC7142374 DOI: 10.1002/mbo3.998] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 01/02/2020] [Accepted: 01/04/2020] [Indexed: 12/11/2022] Open
Abstract
Cell-to-cell early contact between pathogens and their host cells is required for the establishment of many infections. Among various surface factors produced by bacteria that allow an organism to become established in a host, the class of adhesins is a primary determinant. Burkholderia cenocepacia adheres to the respiratory epithelium of cystic fibrosis patients and causes chronic inflammation and disease. Cell-to-cell contacts are promoted by various kinds of adhesins, including trimeric autotransporter adhesins (TAAs). We observed that among the 7 TAA genes found in the B. cenocepacia K56-2 genome, two of them (BCAM2418 and BCAS0236) express higher levels of mRNA following physical contact with host cells. Further analysis revealed that the B. cenocepacia K56-2 BCAM2418 gene shows an on-off switch after an initial colonization period, exhibits a strong expression dependent on the host cell type, and enhances its function on cell adhesion. Furthermore, our analysis revealed that adhesion to mucin-coated surfaces dramatically increases the expression levels of BCAM2418. Abrogation of mucin O-glycans turns BCAM2418 gene expression off and impairs bacterial adherence. Overall, our findings suggest that glycosylated extracellular components of host membrane might be a binding site for B. cenocepacia and a signal for the differential expression of the TAA gene BCAM2418.
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Affiliation(s)
- Andreia I. Pimenta
- iBB‐Institute for Bioengineering and BiosciencesInstituto Superior Técnico, University of LisbonLisbonPortugal
| | - Dalila Mil‐Homens
- iBB‐Institute for Bioengineering and BiosciencesInstituto Superior Técnico, University of LisbonLisbonPortugal
| | - Arsenio M. Fialho
- iBB‐Institute for Bioengineering and BiosciencesInstituto Superior Técnico, University of LisbonLisbonPortugal
- Department of BioengineeringInstituto Superior TécnicoUniversity of LisbonLisbonPortugal
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28
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Serapio-Palacios A, Finlay BB. Dynamics of expression, secretion and translocation of type III effectors during enteropathogenic Escherichia coli infection. Curr Opin Microbiol 2020; 54:67-76. [PMID: 32058947 DOI: 10.1016/j.mib.2019.12.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/30/2019] [Indexed: 12/14/2022]
Abstract
Enteropathogenic Escherichia coli (EPEC) is an important cause of infant diarrhea and mortality worldwide. The locus of enterocyte effacement (LEE) pathogenicity island in the EPEC genome encodes a type 3 secretion system (T3SS). This nanomachine directly injects a sophisticated arsenal of effectors into host cells, which is critical for EPEC pathogenesis. To colonize the gut mucosa, EPEC alters its gene expression in response to host environmental signals. Regulation of the LEE has been studied extensively, revealing key mechanisms of transcriptional regulation, and more recently at the posttranscriptional and posttranslational levels. Moreover, the T3SS assembly and secretion is a highly coordinated process that ensures hierarchical delivery of effectors upon cell contact. EPEC effectors and virulence factors not only manipulate host cellular processes, but also modulate effector translocation by controlling T3SS formation. In this review, we focus on the regulation of EPEC virulence genes and modulation of effector secretion and translocation.
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Affiliation(s)
| | - Barton Brett Finlay
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada; Department of Microbiology and Immunology, University of British Columbia, Vancouver, BC, Canada; Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, BC, Canada.
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29
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Tang J, Xu Z, Huang L, Luo H, Zhu X. Transcriptional regulation in model organisms: recent progress and clinical implications. Open Biol 2019; 9:190183. [PMID: 31744421 PMCID: PMC6893401 DOI: 10.1098/rsob.190183] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
In this review, we will summarize model organisms used by scientists in the laboratory, including Escherichia coli, yeast, Arabidopsis thaliana, nematodes, Drosophila, zebrafish, mice and other animals. We focus on the progress in research exploring different types of E. coli in the human body, and the specific molecular mechanisms by which they play a role in humans. First, we discuss the specific transcriptional regulation mechanism of E. coli in cell development, maturation, ageing and longevity, as well as tumorigenesis and development. Then, we discuss how the synthesis of some important substances in cells is regulated and how this affects biological behaviour. Understanding and applying these mechanisms, presumably, can greatly improve the quality of people's lives as well as increase their lifespan. For example, some E. coli can activate certain cells by secreting insulin-like growth factor-1, thus activating the inflammatory response of the body, while other E. coli can inactivate the immune response of the body by secreting toxic factors.
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Affiliation(s)
- Jiaqi Tang
- The Marine Biomedical Research Institute, Southern Marine Science and Engineering Guangdong Laboratory Zhanjiang, Guangdong Medical University, Zhanjiang 524023, People's Republic of China.,Guangdong Key Laboratory for Research and Development of Natural Drugs, Zhanjiang 524023, People's Republic of China
| | - Zhenhua Xu
- Center for Cancer and Immunology, Brain Tumor Institute, Children's National Health System, Washington, DC 20010, USA
| | - Lianfang Huang
- The Marine Biomedical Research Institute, Southern Marine Science and Engineering Guangdong Laboratory Zhanjiang, Guangdong Medical University, Zhanjiang 524023, People's Republic of China.,Guangdong Key Laboratory for Research and Development of Natural Drugs, Zhanjiang 524023, People's Republic of China
| | - Hui Luo
- The Marine Biomedical Research Institute, Southern Marine Science and Engineering Guangdong Laboratory Zhanjiang, Guangdong Medical University, Zhanjiang 524023, People's Republic of China
| | - Xiao Zhu
- The Marine Biomedical Research Institute, Southern Marine Science and Engineering Guangdong Laboratory Zhanjiang, Guangdong Medical University, Zhanjiang 524023, People's Republic of China.,Guangdong Key Laboratory for Research and Development of Natural Drugs, Zhanjiang 524023, People's Republic of China
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30
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Woodward SE, Krekhno Z, Finlay BB. Here, there, and everywhere: How pathogenicEscherichia colisense and respond to gastrointestinal biogeography. Cell Microbiol 2019; 21:e13107. [DOI: 10.1111/cmi.13107] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 08/22/2019] [Accepted: 08/23/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Sarah E. Woodward
- Department of Microbiology and ImmunologyUniversity of British Columbia Vancouver British Columbia Canada
- Michael Smith LaboratoriesUniversity of British Columbia Vancouver British Columbia Canada
| | - Zakhar Krekhno
- Department of Microbiology and ImmunologyUniversity of British Columbia Vancouver British Columbia Canada
- Michael Smith LaboratoriesUniversity of British Columbia Vancouver British Columbia Canada
| | - B. Brett Finlay
- Department of Microbiology and ImmunologyUniversity of British Columbia Vancouver British Columbia Canada
- Michael Smith LaboratoriesUniversity of British Columbia Vancouver British Columbia Canada
- Department of Biochemistry and Molecular BiologyUniversity of British Columbia Vancouver British Columbia Canada
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31
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Control of Type III Secretion System Effector/Chaperone Ratio Fosters Pathogen Adaptation to Host-Adherent Lifestyle. mBio 2019; 10:mBio.02074-19. [PMID: 31530678 PMCID: PMC6751064 DOI: 10.1128/mbio.02074-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Host colonization by extracellular pathogens often entails the transition from a planktonic lifestyle to a host-attached state. Enteropathogenic E. coli (EPEC), a Gram-negative pathogen, attaches to the intestinal epithelium of the host and employs a type III secretion system (T3SS) to inject effector proteins into the cytoplasm of infected cells. The most abundant effector protein injected is Tir, whose translocation is dependent on the Tir-bound chaperon CesT. Upon Tir injection, the liberated CesT binds to and inhibits the posttranscriptional regulator CsrA, resulting in reprogramming of gene expression in the host-attached bacteria. Thus, adaptation to the host-attached state involves dynamic remodeling of EPEC gene expression, which is mediated by the relative levels of Tir and CesT. Fluctuating from the optimal Tir/CesT ratio results in a decrease in EPEC virulence. Here we elucidate a posttranscriptional circuit that prevents sharp variations from this ratio, thus improving host colonization. The transition from a planktonic lifestyle to a host-attached state is often critical for bacterial virulence. Upon attachment to host cells, enteropathogenic Escherichia coli (EPEC) employs a type III secretion system (T3SS) to inject into the host cells ∼20 effector proteins, including Tir. CesT, which is encoded from the same operon downstream of tir, is a Tir-bound chaperone that facilitates Tir translocation. Upon Tir translocation, the liberated CesT remains in the bacterial cytoplasm and antagonizes the posttranscriptional regulator CsrA, thus eliciting global regulation in the infecting pathogen. Importantly, tight control of the Tir/CesT ratio is vital, since an uncontrolled surge in free CesT levels may repress CsrA in an untimely manner, thus abrogating colonization. We investigated how fluctuations in Tir translation affect the regulation of this ratio. By creating mutations that cause the premature termination of Tir translation, we revealed that the untranslated tir mRNA becomes highly unstable, resulting in a rapid drop in cesT mRNA levels and, thus, CesT levels. This mechanism couples Tir and CesT levels to ensure a stable Tir/CesT ratio. Our results expose an additional level of regulation that enhances the efficacy of the initial interaction of EPEC with the host cell, providing a better understanding of the bacterial switch from the planktonic to the cell-adherent lifestyle.
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32
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Abstract
Phosphorylation events modify bacterial and archaeal proteomes, imparting cells with rapid and reversible responses to specific environmental stimuli or niches. Phosphorylated proteins are generally modified at one or more serine, threonine, or tyrosine residues. Within the last ten years, increasing numbers of global phosphoproteomic surveys of prokaryote species have revealed an abundance of tyrosine-phosphorylated proteins. In some cases, novel phosphorylation-dependent regulatory paradigms for cell division, gene transcription, and protein translation have been identified, suggesting that a wide scope of prokaryotic physiology remains to be characterized. Recent observations of bacterial proteins with putative phosphotyrosine binding pockets or Src homology 2 (SH2)-like domains suggest the presence of phosphotyrosine-dependent protein interaction networks. Here in this minireview, we focus on protein tyrosine phosphorylation, a posttranslational modification once thought to be rare in prokaryotes but which has emerged as an important regulatory facet in microbial biology.
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33
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Abstract
RNA-binding proteins (RBPs) are central to most if not all cellular processes, dictating the fate of virtually all RNA molecules in the cell. Starting with pioneering work on ribosomal proteins, studies of bacterial RBPs have paved the way for molecular studies of RNA-protein interactions. Work over the years has identified major RBPs that act on cellular transcripts at the various stages of bacterial gene expression and that enable their integration into post-transcriptional networks that also comprise small non-coding RNAs. Bacterial RBP research has now entered a new era in which RNA sequencing-based methods permit mapping of RBP activity in a truly global manner in vivo. Moreover, the soaring interest in understudied members of host-associated microbiota and environmental communities is likely to unveil new RBPs and to greatly expand our knowledge of RNA-protein interactions in bacteria.
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Affiliation(s)
- Erik Holmqvist
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Jörg Vogel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Würzburg, Germany. .,Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany.
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34
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Volk M, Vollmer I, Heroven AK, Dersch P. Transcriptional and Post-transcriptional Regulatory Mechanisms Controlling Type III Secretion. Curr Top Microbiol Immunol 2019; 427:11-33. [PMID: 31218505 DOI: 10.1007/82_2019_168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
Type III secretion systems (T3SSs) are utilized by numerous Gram-negative bacteria to efficiently interact with host cells and manipulate their function. Appropriate expression of type III secretion genes is achieved through the integration of multiple control elements and regulatory pathways that ultimately coordinate the activity of a central transcriptional activator usually belonging to the AraC/XylS family. Although several regulatory elements are conserved between different species and families, each pathogen uses a unique set of control factors and mechanisms to adjust and optimize T3SS gene expression to the need and lifestyle of the pathogen. This is reflected by the complex set of sensory systems and diverse transcriptional, post-transcriptional and post-translational control strategies modulating T3SS expression in response to environmental and intrinsic cues. Whereas some pathways regulate solely the T3SS, others coordinately control expression of one or multiple T3SSs together with other virulence factors and fitness traits on a global scale. Over the past years, several common regulatory themes emerged, e.g., environmental control by two-component systems and carbon metabolism regulators or coupling of T3SS induction with host cell contact/translocon-effector secretion. One of the remaining challenges is to resolve the understudied post-transcriptional regulation of T3SS and the dynamics of the control process.
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Affiliation(s)
- Marcel Volk
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Brunswick, Germany
| | - Ines Vollmer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Brunswick, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Brunswick, Germany
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Brunswick, Germany.
- Institute for Infectiology, University Münster, Münster, Germany.
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35
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Kusmierek M, Hoßmann J, Witte R, Opitz W, Vollmer I, Volk M, Heroven AK, Wolf-Watz H, Dersch P. A bacterial secreted translocator hijacks riboregulators to control type III secretion in response to host cell contact. PLoS Pathog 2019; 15:e1007813. [PMID: 31173606 PMCID: PMC6583979 DOI: 10.1371/journal.ppat.1007813] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 06/19/2019] [Accepted: 05/02/2019] [Indexed: 02/05/2023] Open
Abstract
Numerous Gram-negative pathogens use a Type III Secretion System (T3SS) to promote virulence by injecting effector proteins into targeted host cells, which subvert host cell processes. Expression of T3SS and the effectors is triggered upon host cell contact, but the underlying mechanism is poorly understood. Here, we report a novel strategy of Yersinia pseudotuberculosis in which this pathogen uses a secreted T3SS translocator protein (YopD) to control global RNA regulators. Secretion of the YopD translocator upon host cell contact increases the ratio of post-transcriptional regulator CsrA to its antagonistic small RNAs CsrB and CsrC and reduces the degradosome components PNPase and RNase E levels. This substantially elevates the amount of the common transcriptional activator (LcrF) of T3SS/Yop effector genes and triggers the synthesis of associated virulence-relevant traits. The observed hijacking of global riboregulators allows the pathogen to coordinate virulence factor expression and also readjusts its physiological response upon host cell contact.
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Affiliation(s)
- Maria Kusmierek
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jörn Hoßmann
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Rebekka Witte
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Wiebke Opitz
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Vollmer
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
| | - Marcel Volk
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
| | - Ann Kathrin Heroven
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Hans Wolf-Watz
- Department of Molecular Biology, Umea University, Sweden
| | - Petra Dersch
- Department of Molecular Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- Institute for Infectiology, University of Münster, Germany
- * E-mail:
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Babitzke P, Lai YJ, Renda AJ, Romeo T. Posttranscription Initiation Control of Gene Expression Mediated by Bacterial RNA-Binding Proteins. Annu Rev Microbiol 2019; 73:43-67. [PMID: 31100987 DOI: 10.1146/annurev-micro-020518-115907] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
RNA-binding proteins play vital roles in regulating gene expression and cellular physiology in all organisms. Bacterial RNA-binding proteins can regulate transcription termination via attenuation or antitermination mechanisms, while others can repress or activate translation initiation by affecting ribosome binding. The RNA targets for these proteins include short repeated sequences, longer single-stranded sequences, RNA secondary or tertiary structure, and a combination of these features. The activity of these proteins can be influenced by binding of metabolites, small RNAs, or other proteins, as well as by phosphorylation events. Some of these proteins regulate specific genes, while others function as global regulators. As the regulatory mechanisms, components, targets, and signaling circuitry surrounding RNA-binding proteins have become better understood, in part through rapid advances provided by systems approaches, a sense of the true nature of biological complexity is becoming apparent, which we attempt to capture for the reader of this review.
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Affiliation(s)
- Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA; ,
| | - Ying-Jung Lai
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA; ,
| | - Andrew J Renda
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA; ,
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA; ,
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Pal RR, Baidya AK, Mamou G, Bhattacharya S, Socol Y, Kobi S, Katsowich N, Ben-Yehuda S, Rosenshine I. Pathogenic E. coli Extracts Nutrients from Infected Host Cells Utilizing Injectisome Components. Cell 2019; 177:683-696.e18. [DOI: 10.1016/j.cell.2019.02.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 09/21/2018] [Accepted: 02/13/2019] [Indexed: 12/18/2022]
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Potts AH, Guo Y, Ahmer BMM, Romeo T. Role of CsrA in stress responses and metabolism important for Salmonella virulence revealed by integrated transcriptomics. PLoS One 2019; 14:e0211430. [PMID: 30682134 PMCID: PMC6347204 DOI: 10.1371/journal.pone.0211430] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/14/2019] [Indexed: 12/31/2022] Open
Abstract
To cause infection, Salmonella must survive and replicate in host niches that present dramatically different environmental conditions. This requires a flexible metabolism and physiology, responsive to conditions of the local milieu. The sequence specific RNA binding protein CsrA serves as a global regulator that governs gene expression required for pathogenicity, metabolism, biofilm formation, and motility in response to nutritional conditions. Its activity is determined by two noncoding small RNAs (sRNA), CsrB and CsrC, which sequester and antagonize this protein. Here, we used ribosome profiling and RNA-seq analysis to comprehensively examine the effects of CsrA on mRNA occupancy with ribosomes, a measure of translation, transcript stability, and the steady state levels of transcripts under in vitro SPI-1 inducing conditions, to simulate growth in the intestinal lumen, and under in vitro SPI-2-inducing conditions, to simulate growth in the Salmonella containing vacuole (SCV) of the macrophage. Our findings uncovered new roles for CsrA in controlling the expression of structural and regulatory genes involved in stress responses, metabolism, and virulence systems required for infection. We observed substantial variation in the CsrA regulon under the two growth conditions. In addition, CsrB/C sRNA levels were greatly reduced under the simulated intracellular conditions and were responsive to nutritional factors that distinguish the intracellular and luminal environments. Altogether, our results reveal CsrA to be a flexible regulator, which is inferred to be intimately involved in maintaining the distinct gene expression patterns associated with growth in the intestine and the macrophage.
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Affiliation(s)
- Anastasia H Potts
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| | - Yinping Guo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
| | - Brian M M Ahmer
- Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, United States of America
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL, United States of America
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Abstract
Bacterial regulatory RNAs are key players in adaptation to changing environmental conditions and response to diverse cellular stresses. However, while regulatory RNAs of bacterial pathogens have been intensely studied under defined conditions in vitro, characterization of their role during the infection of eukaryotic host organisms is lagging behind. This review summarizes our current understanding of the contribution of the different classes of regulatory RNAs and RNA-binding proteins to bacterial virulence and illustrates their role in infection by reviewing the mechanisms of some prominent representatives of each class. Emerging technologies are described that bear great potential for global, unbiased studies of virulence-related RNAs in bacterial model and nonmodel pathogens in the future. The review concludes by deducing common principles of RNA-mediated gene expression control of virulence programs in different pathogens, and by defining important open questions for upcoming research in the field.
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40
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Metabolome and transcriptome-wide effects of the carbon storage regulator A in enteropathogenic Escherichia coli. Sci Rep 2019; 9:138. [PMID: 30644424 PMCID: PMC6333774 DOI: 10.1038/s41598-018-36932-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 11/28/2018] [Indexed: 02/06/2023] Open
Abstract
The carbon storage regulator A (CsrA) is a conserved global regulatory system known to control central carbon pathways, biofilm formation, motility, and pathogenicity. The aim of this study was to characterize changes in major metabolic pathways induced by CsrA in human enteropathogenic Escherichia coli (EPEC) grown under virulence factor-inducing conditions. For this purpose, the metabolomes and transcriptomes of EPEC and an isogenic ∆csrA mutant derivative were analyzed by untargeted mass spectrometry and RNA sequencing, respectively. Of the 159 metabolites identified from untargeted GC/MS and LC/MS data, 97 were significantly (fold change ≥ 1.5; corrected p-value ≤ 0.05) regulated between the knockout and the wildtype strain. A lack of csrA led to an accumulation of fructose-6-phosphate (F6P) and glycogen synthesis pathway products, whereas metabolites in lower glycolysis and the citric acid cycle were downregulated. Associated pathways from the citric acid cycle like aromatic amino acid and siderophore biosynthesis were also negatively influenced. The nucleoside salvage pathways were featured by an accumulation of nucleosides and nucleobases, and a downregulation of nucleotides. In addition, a pronounced downregulation of lyso-lipid metabolites was observed. A drastic change in the morphology in the form of vesicle-like structures of the ∆csrA knockout strain was visible by electron microscopy. Colanic acid synthesis genes were strongly (up to 50 fold) upregulated, and the abundance of colanic acid was 3 fold increased according to a colorimetric assay. The findings expand the scope of pathways affected by the csrA regulon and emphasize its importance as a global regulator.
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Control freaks-signals and cues governing the regulation of virulence in attaching and effacing pathogens. Biochem Soc Trans 2018; 47:229-238. [PMID: 30559275 PMCID: PMC6393859 DOI: 10.1042/bst20180546] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/08/2018] [Accepted: 11/13/2018] [Indexed: 02/07/2023]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) mediates disease using a type 3 secretion system (T3SS), which is encoded on the locus of enterocyte effacement (LEE) and is tightly controlled by master regulators. This system is further modulated by a number of signals that help to fine-tune virulence, including metabolic, environmental and chemical signals. Since the LEE and its master regulator, Ler, were established, there have been numerous scientific advancements in understanding the regulation and expression of virulence factors in EHEC. This review will discuss the recent advancements in this field since our previous review, with a focus on the transcriptional regulation of the LEE.
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Abstract
The sequence-specific RNA binding protein CsrA is employed by diverse bacteria in the posttranscriptional regulation of gene expression. Its binding interactions with RNA have been documented at atomic resolution and shown to alter RNA secondary structure, RNA stability, translation, and/or Rho-mediated transcription termination through a growing number of molecular mechanisms. In Gammaproteobacteria, small regulatory RNAs (sRNAs) that contain multiple CsrA binding sites compete with mRNA for binding to CsrA, thereby sequestering and antagonizing this protein. Both the synthesis and turnover of these sRNAs are regulated, allowing CsrA activity to be rapidly and efficiently adjusted in response to nutritional conditions and stresses. Feedback loops between the Csr regulatory components improve the dynamics of signal response by the Csr system. The Csr system of Escherichia coli is intimately interconnected with other global regulatory systems, permitting it to contribute to regulation by those systems. In some species, a protein antagonist of CsrA functions as part of a checkpoint for flagellum biosynthesis. In other species, a protein antagonist participates in a mechanism in which a type III secretion system is used for sensing interactions with host cells. Recent transcriptomics studies reveal vast effects of CsrA on gene expression through direct binding to hundreds of mRNAs, and indirectly through its effects on the expression of dozens of transcription factors. CsrA binding to base-pairing sRNAs and novel mRNA segments, such as the 3' untranslated region and deep within coding regions, predict its participation in yet-to-be-discovered regulatory mechanisms.
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43
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Choy AT, Carnevale I, Coppola S, Meijer LL, Kazemier G, Zaura E, Deng D, Giovannetti E. The microbiome of pancreatic cancer: from molecular diagnostics to new therapeutic approaches to overcome chemoresistance caused by metabolic inactivation of gemcitabine. Expert Rev Mol Diagn 2018; 18:1005-1009. [PMID: 30392417 DOI: 10.1080/14737159.2018.1544495] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Arthur T.F. Choy
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - Ilaria Carnevale
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
- Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, VU University Amsterdam, Amsterdam, The Netherlands
- Cancer Pharmacology Lab, AIRC Start-UP Unit, University of Pisa, Pisa, Italy
| | - Stefano Coppola
- Physics of Life Processes, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Leiden, The Netherlands
| | - Laura L. Meijer
- Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, VU University Amsterdam, Amsterdam, The Netherlands
- Department of Surgery, Cancer Center Amsterdam, Amsterdam UMC, VU University Amsterdam, Amsterdam, The Netherlands
| | - Geert Kazemier
- Department of Surgery, Cancer Center Amsterdam, Amsterdam UMC, VU University Amsterdam, Amsterdam, The Netherlands
| | - Egija Zaura
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - Dongmei Deng
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - Elisa Giovannetti
- Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, VU University Amsterdam, Amsterdam, The Netherlands
- Cancer Pharmacology Lab, AIRC Start-UP Unit, University of Pisa, Pisa, Italy
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Host-associated niche metabolism controls enteric infection through fine-tuning the regulation of type 3 secretion. Nat Commun 2018; 9:4187. [PMID: 30305622 PMCID: PMC6180029 DOI: 10.1038/s41467-018-06701-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 09/14/2018] [Indexed: 12/31/2022] Open
Abstract
Niche-adaptation of a bacterial pathogen hinges on the ability to recognize the complexity of signals from the environment and integrate that information with the regulation of genes critical for infection. Here we report the transcriptome of the attaching and effacing pathogen Citrobacter rodentium during infection of its natural murine host. Pathogen gene expression in vivo was heavily biased towards the virulence factor repertoire and was found to be co-ordinated uniquely in response to the host. Concordantly, we identified the host-specific induction of a metabolic pathway that overlapped with the regulation of virulence. The essential type 3 secretion system and an associated suite of distinct effectors were found to be modulated co-ordinately through a unique mechanism involving metabolism of microbiota-derived 1,2-propanediol, which dictated the ability to colonize the host effectively. This study provides novel insights into how host-specific metabolic adaptation acts as a cue to fine-tune virulence. Infection of mice with Citrobacter rodentium is a common model of infection with attaching-and-effacing pathogens. Here, Connolly et al. analyse the transcriptome of C. rodentium during mouse infection, showing host-induced coordinated upregulation of virulence factors and 1,2-propanediol metabolism.
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45
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Transcriptome-Wide Analysis of Protein-RNA and RNA-RNA Interactions in Pathogenic Bacteria. Methods Enzymol 2018; 612:467-488. [PMID: 30502953 DOI: 10.1016/bs.mie.2018.08.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Regulatory RNAs and RNA-binding proteins (RBPs) play critical roles in virulence gene expression in pathogenic bacteria. A wealth of regulatory RNAs have been identified in bacterial pathogens using RNA-seq and recent technical advances are uncovering their mRNA targets. UV-crosslinking is a powerful tool for identifying protein binding sites throughout the transcriptome providing base-pair resolution of sites in vivo. With minor modifications to the protocol, RNA-RNA interactions can also be captured by proximity-dependent ligation of RNA pairs on the protein. Here, we described a high-stringency UV-crosslinking method for recovery of both protein-RNA interactions (CRAC) and RNA-RNA interactions occurring on the bait protein (CLASH). These analyses provide complementary data that provide insights into RBP, and regulatory RNA function.
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46
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After the Fact(or): Posttranscriptional Gene Regulation in Enterohemorrhagic Escherichia coli O157:H7. J Bacteriol 2018; 200:JB.00228-18. [PMID: 29967119 DOI: 10.1128/jb.00228-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To adapt to ever-changing environments, pathogens quickly alter gene expression. This can occur through transcriptional, posttranscriptional, or posttranslational regulation. Historically, transcriptional regulation has been thoroughly studied to understand pathogen niche adaptation, whereas posttranscriptional and posttranslational gene regulation has only relatively recently been appreciated to play a central role in bacterial pathogenesis. Posttranscriptional regulation may involve chaperones, nucleases, and/or noncoding small RNAs (sRNAs) and typically controls gene expression by altering the stability and/or translation of the target mRNA. In this review, we highlight the global importance of posttranscriptional regulation to enterohemorrhagic Escherichia coli (EHEC) gene expression and discuss specific mechanisms of how EHEC regulates expression of virulence factors critical to host colonization and disease progression. The low infectious dose of this intestinal pathogen suggests that EHEC is particularly well adapted to respond to the host environment.
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47
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Molecular basis for CesT recognition of type III secretion effectors in enteropathogenic Escherichia coli. PLoS Pathog 2018; 14:e1007224. [PMID: 30118511 PMCID: PMC6114900 DOI: 10.1371/journal.ppat.1007224] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 08/29/2018] [Accepted: 07/17/2018] [Indexed: 11/19/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) use a needle-like injection apparatus known as the type III secretion system (T3SS) to deliver protein effectors into host cells. Effector translocation is highly stratified in EPEC with the translocated intimin receptor (Tir) being the first effector delivered into the host. CesT is a multi-cargo chaperone that is required for the secretion of Tir and at least 9 other effectors. However, the structural and mechanistic basis for differential effector recognition by CesT remains unclear. Here, we delineated the minimal CesT-binding region on Tir to residues 35–77 and determined the 2.74 Å structure of CesT bound to an N-terminal fragment of Tir. Our structure revealed that the CesT-binding region in the N-terminus of Tir contains an additional conserved sequence, distinct from the known chaperone-binding β-motif, that we termed the CesT-extension motif because it extends the β-sheet core of CesT. This motif is also present in the C-terminus of Tir that we confirmed to be a unique second CesT-binding region. Point mutations that disrupt CesT-binding to the N- or C-terminus of Tir revealed that the newly identified carboxy-terminal CesT-binding region was required for efficient Tir translocation into HeLa cells and pedestal formation. Furthermore, the CesT-extension motif was identified in the N-terminal region of NleH1, NleH2, and EspZ, and mutations that disrupt this motif reduced translocation of these effectors, and in some cases, overall effector stability, thus validating the universality of this CesT-extension motif. The presence of two CesT-binding regions in Tir, along with the presence of the CesT-extension motif in other highly translocated effectors, may contribute to differential cargo recognition by CesT. Enteropathogenic Escherichia coli injects effector proteins into host cells using a type III secretion system (T3SS). The translocated intimin receptor (Tir) is the first effector delivered into host cells and imparts efficient secretion of other effectors. However, the mechanism for Tir-dependent modulation of the T3SS is poorly understood. We provide evidence that the multi-cargo chaperone CesT binds to two regions in Tir at the N- and C-terminus through a specific recognition motif, and show that CesT binding to the Tir C-terminus is important for host translocation. Furthermore we show that the CesT-specific motif is conserved in a subset of highly translocated effectors. This study highlights the multi-faceted role that T3SS chaperones play in effector secretion dynamics.
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48
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Platenkamp A, Mellies JL. Environment Controls LEE Regulation in Enteropathogenic Escherichia coli. Front Microbiol 2018; 9:1694. [PMID: 30140259 PMCID: PMC6094958 DOI: 10.3389/fmicb.2018.01694] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 07/09/2018] [Indexed: 12/11/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) is a significant cause of infant morbidity and mortality in developing regions of the world. Horizontally acquired genetic elements encode virulence structures, effectors, and regulators that promote bacterial colonization and disease. One such genetic element, the locus of enterocyte effacement (LEE), encodes the type three secretion system (T3SS) which acts as a bridge between bacterial and host cells to pass effector molecules that exert changes on the host. Due to its importance in EPEC virulence, regulation of the LEE has been of high priority and its investigation has elucidated many virulence regulators, including master regulator of the LEE Ler, H-NS, other nucleoid-associated proteins, GrlA, and PerC. Media type, environmental signals, sRNA signaling, metabolic processes, and stress responses have profound, strain-specific effects on regulators and LEE expression, and thus T3SS formation. Here we review virulence gene regulation in EPEC, which includes approaches for lessening disease by exploiting the elucidated regulatory pathways.
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Affiliation(s)
- Amy Platenkamp
- Department of Biology, Reed College, Portland, OR, United States
| | - Jay L Mellies
- Department of Biology, Reed College, Portland, OR, United States
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49
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CsrA and its regulators control the time-point of ColicinE2 release in Escherichia coli. Sci Rep 2018; 8:6537. [PMID: 29695793 PMCID: PMC5916893 DOI: 10.1038/s41598-018-24699-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 04/09/2018] [Indexed: 01/09/2023] Open
Abstract
The bacterial SOS response is a cellular reaction to DNA damage, that, among other actions, triggers the expression of colicin - toxic bacteriocins in Escherichia coli that are released to kill close relatives competing for resources. However, it is largely unknown, how the complex network regulating toxin expression controls the time-point of toxin release to prevent premature release of inefficient protein concentrations. Here, we study how different regulatory mechanisms affect production and release of the bacteriocin ColicinE2 in Escherichia coli. Combining experimental and theoretical approaches, we demonstrate that the global carbon storage regulator CsrA controls the duration of the delay between toxin production and release and emphasize the importance of CsrA sequestering elements for the timing of ColicinE2 release. In particular, we show that ssDNA originating from rolling-circle replication of the toxin-producing plasmid represents a yet unknown additional CsrA sequestering element, which is essential in the ColicinE2-producing strain to enable toxin release by reducing the amount of free CsrA molecules in the bacterial cell. Taken together, our findings show that CsrA times ColicinE2 release and reveal a dual function for CsrA as an ssDNA and mRNA-binding protein, introducing ssDNA as an important post-transcriptional gene regulatory element.
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50
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McAteer SP, Sy BM, Wong JL, Tollervey D, Gally DL, Tree JJ. Ribosome maturation by the endoribonuclease YbeY stabilizes a type 3 secretion system transcript required for virulence of enterohemorrhagic Escherichia coli. J Biol Chem 2018; 293:9006-9016. [PMID: 29678883 PMCID: PMC5995498 DOI: 10.1074/jbc.ra117.000300] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 04/17/2018] [Indexed: 12/11/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is a significant human pathogen that colonizes humans and its reservoir host, cattle. Colonization requires the expression of a type 3 secretion (T3S) system that injects a mixture of effector proteins into host cells to promote bacterial attachment and disease progression. The T3S system is tightly regulated by a complex network of transcriptional and post-transcriptional regulators. Using transposon mutagenesis, here we identified the ybeZYX-Int operon as being required for normal T3S levels. Deletion analyses localized the regulation to the endoribonuclease YbeY, previously linked to 16S rRNA maturation and small RNA (sRNA) function. Loss of ybeY in EHEC had pleiotropic effects on EHEC cells, including reduced motility and growth and cold sensitivity. Using UV cross-linking and RNA-Seq (CRAC) analysis, we identified YbeY-binding sites throughout the transcriptome and discovered specific binding of YbeY to the "neck" and "beak" regions of 16S rRNA but identified no significant association of YbeY with sRNA, suggesting that YbeY modulates T3S by depleting mature ribosomes. In E. coli, translation is strongly linked to mRNA stabilization, and subinhibitory concentrations of the translation-initiation inhibitor kasugamycin provoked rapid degradation of a polycistronic mRNA encoding needle filament and needle tip proteins of the T3S system. We conclude that T3S is particularly sensitive to depletion of initiating ribosomes, explaining the inhibition of T3S in the ΔybeY strain. Accessory virulence transcripts may be preferentially degraded in cells with reduced translational capacity, potentially reflecting prioritization in protein production.
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Affiliation(s)
- Sean P McAteer
- From the Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, Scotland, United Kingdom
| | - Brandon M Sy
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, Sydney 2033, Australia, and
| | - Julia L Wong
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, Sydney 2033, Australia, and
| | - David Tollervey
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, United Kingdom
| | - David L Gally
- From the Division of Infection and Immunity, The Roslin Institute, University of Edinburgh, Edinburgh EH25 9RG, Scotland, United Kingdom,
| | - Jai J Tree
- School of Biotechnology and Biomolecular Sciences, University of New South Wales Sydney, Sydney 2033, Australia, and
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