1
|
Saunier M, Fortier LC, Soutourina O. RNA-based regulation in bacteria-phage interactions. Anaerobe 2024; 87:102851. [PMID: 38583547 DOI: 10.1016/j.anaerobe.2024.102851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 03/24/2024] [Accepted: 04/02/2024] [Indexed: 04/09/2024]
Abstract
Interactions of bacteria with their viruses named bacteriophages or phages shape the bacterial genome evolution and contribute to the diversity of phages. RNAs have emerged as key components of several anti-phage defense systems in bacteria including CRISPR-Cas, toxin-antitoxin and abortive infection. Frequent association with mobile genetic elements and interplay between different anti-phage defense systems are largely discussed. Newly discovered defense systems such as retrons and CBASS include RNA components. RNAs also perform their well-recognized regulatory roles in crossroad of phage-bacteria regulatory networks. Both regulatory and defensive function can be sometimes attributed to the same RNA molecules including CRISPR RNAs. This review presents the recent advances on the role of RNAs in the bacteria-phage interactions with a particular focus on clostridial species including an important human pathogen, Clostridioides difficile.
Collapse
Affiliation(s)
- Marion Saunier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France; Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Louis-Charles Fortier
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada
| | - Olga Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France; Institut Universitaire de France (IUF), Paris, France.
| |
Collapse
|
2
|
Sprenger M, Siemers M, Krautwurst S, Papenfort K. Small RNAs direct attack and defense mechanisms in a quorum sensing phage and its host. Cell Host Microbe 2024; 32:727-738.e6. [PMID: 38579715 DOI: 10.1016/j.chom.2024.03.010] [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: 11/21/2023] [Revised: 02/02/2024] [Accepted: 03/13/2024] [Indexed: 04/07/2024]
Abstract
Many, if not all, bacteria use quorum sensing (QS) to control collective behaviors, and more recently, QS has also been discovered in bacteriophages (phages). Phages can produce communication molecules of their own, or "listen in" on the host's communication processes, to switch between lytic and lysogenic modes of infection. Here, we study the interaction of Vibrio cholerae with the lysogenic phage VP882, which is activated by the QS molecule DPO. We discover that induction of VP882 results in the binding of phage transcripts to the major RNA chaperone Hfq, which in turn outcompetes and downregulates host-encoded small RNAs (sRNAs). VP882 itself also encodes Hfq-binding sRNAs, and we demonstrate that one of these sRNAs, named VpdS, promotes phage replication by regulating host and phage mRNA levels. We further show that host-encoded sRNAs can antagonize phage replication by downregulating phage mRNA expression and thus might be part of the host's phage defense arsenal.
Collapse
Affiliation(s)
- Marcel Sprenger
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany
| | - Malte Siemers
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany; Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany
| | | | - Kai Papenfort
- Friedrich Schiller University, Institute of Microbiology, 07745 Jena, Germany; Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany.
| |
Collapse
|
3
|
Dunham DT, Angermeyer A, Seed KD. The RNA-RNA interactome between a phage and its satellite virus reveals a small RNA that differentially regulates gene expression across both genomes. Mol Microbiol 2023; 119:515-533. [PMID: 36786209 PMCID: PMC10392615 DOI: 10.1111/mmi.15046] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
Satellite viruses are present across all domains of life, defined as subviral parasites that require infection by another virus for satellite progeny production. Phage satellites exhibit various regulatory mechanisms to manipulate phage gene expression to the benefit of the satellite, redirecting resources from the phage to the satellite, and often inhibiting phage progeny production. While small RNAs (sRNAs) are well documented as regulators of prokaryotic gene expression, they have not been shown to play a regulatory role in satellite-phage conflicts. Vibrio cholerae encodes the phage inducible chromosomal island-like element (PLE), a phage satellite, to defend itself against the lytic phage ICP1. Here, we use Hi-GRIL-seq to identify a complex RNA-RNA interactome between PLE and ICP1. Both inter- and intragenome RNA interactions were detected, headlined by the PLE sRNA, SviR. SviR is involved in regulating both PLE and ICP1 gene expression uniquely, decreasing ICP1 target translation and affecting PLE transcripts. The striking conservation of SviR across all known PLEs suggests the sRNA is deeply rooted in the PLE-ICP1 conflict and implicates sRNAs as unidentified regulators of gene expression in phage-satellite interactions.
Collapse
Affiliation(s)
- Drew T Dunham
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Angus Angermeyer
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| | - Kimberley D Seed
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, USA
| |
Collapse
|
4
|
Clostridioides difficile - phage relationship the RNA way. Curr Opin Microbiol 2021; 66:1-10. [PMID: 34922145 DOI: 10.1016/j.mib.2021.11.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/06/2021] [Accepted: 11/28/2021] [Indexed: 12/17/2022]
Abstract
Clostridioides difficile (formerly Clostridium difficile)-associated diarrhea is currently the most frequently occurring nosocomial diarrhea worldwide. During its infection cycle this pathogen needs to survive in phage-rich gut communities. Recent data strongly suggest that regulatory RNAs control gene expression in C. difficile and many of these RNAs appear to modulate C. difficile-phage interactions. Of the 200 regulatory RNAs identified by deep sequencing and targeted approaches, many function as antitoxins within type I toxin-antitoxin modules and CRISPR RNAs for anti-phage defenses. In this review, we discuss recent insights into the role of RNAs in modulating interactions between C. difficile and phages in light of intriguing data in other prokaryotes.
Collapse
|
5
|
Tej S, Mukherji S. Small RNA-driven feed-forward loop: fine-tuning of protein synthesis through sRNA-mediated crosstalk. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2021; 44:55. [PMID: 33871749 DOI: 10.1140/epje/s10189-021-00013-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 01/05/2021] [Indexed: 06/12/2023]
Abstract
Often in bacterial regulatory networks, small non-coding RNAs (sRNA) interact with several mRNA species. The competition among mRNAs for binding to the common pool of sRNA might lead to crosstalk between the mRNAs. This is similar to the competing endogenous RNA effect that leads to complex gene regulation with stabilized gene expression in Eukaryotes. Here, we study an sRNA-driven feed-forward loop (sFFL) where the top-tier regulator, an sRNA, translationally activates the target protein (TP) as well as a transcriptional activator of the TP through binding to the respective mRNAs. We show that the sRNA-mediated crosstalk between the two mRNA species enables the sFFL to function in three different regimes depending on the synthesis rate of the transcriptional activator mRNA. Of these three regimes, there exists a sensitive regime where the TP level shows interesting features depending on the precise mechanism of target translation. In the case of translation entirely from sRNA-mRNA bound complexes, the TP level becomes maximum around the sensitive regime. Through stochastic analysis and simulations, we show that relative fluctuations in the TP level is minimized here. For translation both from mRNA and sRNA-mRNA bound complexes, the target expression shows a threshold response across the sensitive regime.
Collapse
Affiliation(s)
- Swathi Tej
- Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore, Karnataka, 570 020, India
| | - Sutapa Mukherji
- Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore, Karnataka, 570 020, India.
- Mathematical and Physical Sciences Division, School of Arts and Sciences, Ahmedabad University, Navrangpura, Ahmedabad, 380009, India.
| |
Collapse
|
6
|
Mediati DG, Wu S, Wu W, Tree JJ. Networks of Resistance: Small RNA Control of Antibiotic Resistance. Trends Genet 2020; 37:35-45. [PMID: 32951948 DOI: 10.1016/j.tig.2020.08.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/13/2020] [Accepted: 08/20/2020] [Indexed: 12/20/2022]
Abstract
The golden age of antibiotics has passed, and the threat of untreatable antimicrobial resistant infections is now a reality for many individuals. Understanding how bacteria resist antimicrobial treatment and regulate gene expression in response to antibiotics is an important step towards combating resistance. In this review we focus on a ubiquitous class of bacterial gene regulators termed regulatory small RNAs (sRNAs) and how they contribute to antimicrobial resistance and tolerance. Small RNAs have notable roles in modulating the composition of the bacterial envelope, and through these functions control intrinsic antimicrobial resistance in many human pathogens. Recent technical advances that allow profiling of the 'sRNA interactome' have revealed a complex post-transcriptional network of sRNA interactions that can be used to identify network hubs and regulatory bottlenecks. Sequence-specific inhibition of these sRNAs with programmable RNA-targeting therapeutics may present avenues for treating antimicrobial resistant pathogens or resensitizing to our current antibiotics.
Collapse
Affiliation(s)
- Daniel G Mediati
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Sylvania Wu
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Winton Wu
- 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.
| |
Collapse
|
7
|
Maertens L, Leys N, Matroule JY, Van Houdt R. The Transcriptomic Landscape of Cupriavidus metallidurans CH34 Acutely Exposed to Copper. Genes (Basel) 2020; 11:E1049. [PMID: 32899882 PMCID: PMC7563307 DOI: 10.3390/genes11091049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 09/02/2020] [Indexed: 12/14/2022] Open
Abstract
Bacteria are increasingly used for biotechnological applications such as bioremediation, biorecovery, bioproduction, and biosensing. The development of strains suited for such applications requires a thorough understanding of their behavior, with a key role for their transcriptomic landscape. We present a thorough analysis of the transcriptome of Cupriavidus metallidurans CH34 cells acutely exposed to copper by tagRNA-sequencing. C. metallidurans CH34 is a model organism for metal resistance, and its potential as a biosensor and candidate for metal bioremediation has been demonstrated in multiple studies. Several metabolic pathways were impacted by Cu exposure, and a broad spectrum of metal resistance mechanisms, not limited to copper-specific clusters, was overexpressed. In addition, several gene clusters involved in the oxidative stress response and the cysteine-sulfur metabolism were induced. In total, 7500 transcription start sites (TSSs) were annotated and classified with respect to their location relative to coding sequences (CDSs). Predicted TSSs were used to re-annotate 182 CDSs. The TSSs of 2422 CDSs were detected, and consensus promotor logos were derived. Interestingly, many leaderless messenger RNAs (mRNAs) were found. In addition, many mRNAs were transcribed from multiple alternative TSSs. We observed pervasive intragenic TSSs both in sense and antisense to CDSs. Antisense transcripts were enriched near the 5' end of mRNAs, indicating a functional role in post-transcriptional regulation. In total, 578 TSSs were detected in intergenic regions, of which 35 were identified as putative small regulatory RNAs. Finally, we provide a detailed analysis of the main copper resistance clusters in CH34, which include many intragenic and antisense transcripts. These results clearly highlight the ubiquity of noncoding transcripts in the CH34 transcriptome, many of which are putatively involved in the regulation of metal resistance.
Collapse
Affiliation(s)
- Laurens Maertens
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), 2400 Mol, Belgium; (L.M.); (N.L.)
- Research Unit in Microorganisms Biology (URBM), Narilis Institute, University of Namur, 5000 Namur, Belgium;
| | - Natalie Leys
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), 2400 Mol, Belgium; (L.M.); (N.L.)
| | - Jean-Yves Matroule
- Research Unit in Microorganisms Biology (URBM), Narilis Institute, University of Namur, 5000 Namur, Belgium;
| | - Rob Van Houdt
- Microbiology Unit, Interdisciplinary Biosciences, Belgian Nuclear Research Centre (SCK CEN), 2400 Mol, Belgium; (L.M.); (N.L.)
| |
Collapse
|
8
|
Sobrero PM, Valverde C. Comparative Genomics and Evolutionary Analysis of RNA-Binding Proteins of the CsrA Family in the Genus Pseudomonas. Front Mol Biosci 2020; 7:127. [PMID: 32754614 PMCID: PMC7366521 DOI: 10.3389/fmolb.2020.00127] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Accepted: 06/02/2020] [Indexed: 12/15/2022] Open
Abstract
Gene expression is adjusted according to cellular needs through a combination of mechanisms acting at different layers of the flow of genetic information. At the posttranscriptional level, RNA-binding proteins are key factors controlling the fate of nascent and mature mRNAs. Among them, the members of the CsrA family are small dimeric proteins with heterogeneous distribution across the bacterial tree of life, that act as global regulators of gene expression because they recognize characteristic sequence/structural motifs (short hairpins with GGA triplets in the loop) present in hundreds of mRNAs. The regulatory output of CsrA binding to mRNAs is counteracted in most cases by molecular mimic, non-protein coding RNAs that titrate the CsrA dimers away from the target mRNAs. In γ-proteobacteria, the regulatory modules composed by CsrA homologs and the corresponding antagonistic sRNAs, are mastered by two-component systems of the GacS-GacA type, which control the transcription and the abundance of the sRNAs, thus constituting the rather linear cascade Gac-Rsm that responds to environmental or cellular signals to adjust and coordinate the expression of a set of target genes posttranscriptionally. Within the γ-proteobacteria, the genus Pseudomonas has been shown to contain species with different number of active CsrA (RsmA) homologs and of molecular mimic sRNAs. Here, with the help of the increasing availability of genomic data we provide a comprehensive state-of-the-art picture of the remarkable multiplicity of CsrA lineages, including novel yet uncharacterized paralogues, and discuss evolutionary aspects of the CsrA subfamilies of the genus Pseudomonas, and implications of the striking presence of csrA alleles in natural mobile genetic elements (phages and plasmids).
Collapse
Affiliation(s)
- Patricio Martín Sobrero
- Laboratorio de Fisiología y Genética de Bacterias Beneficiosas para Plantas, Centro de Bioquímica y Microbiología del Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes - CONICET, Buenos Aires, Argentina
| | - Claudio Valverde
- Laboratorio de Fisiología y Genética de Bacterias Beneficiosas para Plantas, Centro de Bioquímica y Microbiología del Suelo, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes - CONICET, Buenos Aires, Argentina
| |
Collapse
|
9
|
Diel B, Dequivre M, Wisniewski‐Dyé F, Vial L, Hommais F. A novel plasmid‐transcribed regulatory sRNA, QfsR, controls chromosomal polycistronic gene expression in
Agrobacterium fabrum. Environ Microbiol 2019; 21:3063-3075. [DOI: 10.1111/1462-2920.14704] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 06/04/2019] [Indexed: 01/06/2023]
Affiliation(s)
- Benjamin Diel
- Université de Lyon F‐69622 Lyon France
- Université Lyon 1 F‐69622 Villeurbanne France
- CNRSUMR 5240 Microbiologie Adaptation et Pathogénie F‐69622 Villeurbanne France
- CNRSUMR 5557 Ecologie Microbienne F‐69622 Villeurbanne France
- INRAUMR1418 Ecologie Microbienne F‐69622 Villeurbanne France
| | - Magali Dequivre
- Université de Lyon F‐69622 Lyon France
- Université Lyon 1 F‐69622 Villeurbanne France
- CNRSUMR 5240 Microbiologie Adaptation et Pathogénie F‐69622 Villeurbanne France
| | - Florence Wisniewski‐Dyé
- Université de Lyon F‐69622 Lyon France
- Université Lyon 1 F‐69622 Villeurbanne France
- CNRSUMR 5557 Ecologie Microbienne F‐69622 Villeurbanne France
- INRAUMR1418 Ecologie Microbienne F‐69622 Villeurbanne France
| | - Ludovic Vial
- Université de Lyon F‐69622 Lyon France
- Université Lyon 1 F‐69622 Villeurbanne France
- CNRSUMR 5557 Ecologie Microbienne F‐69622 Villeurbanne France
- INRAUMR1418 Ecologie Microbienne F‐69622 Villeurbanne France
| | - Florence Hommais
- Université de Lyon F‐69622 Lyon France
- Université Lyon 1 F‐69622 Villeurbanne France
- CNRSUMR 5240 Microbiologie Adaptation et Pathogénie F‐69622 Villeurbanne France
| |
Collapse
|
10
|
Parmeciano Di Noto G, Molina MC, Quiroga C. Insights Into Non-coding RNAs as Novel Antimicrobial Drugs. Front Genet 2019; 10:57. [PMID: 30853970 PMCID: PMC6395445 DOI: 10.3389/fgene.2019.00057] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 01/24/2019] [Indexed: 12/21/2022] Open
Abstract
Multidrug resistant bacteria are a serious worldwide problem, especially carbapenem-resistant Enterobacteriaceae (such as Klebsiella pneumoniae and Escherichia coli), Acinetobacter baumannii and Pseudomonas aeruginosa. Since the emergence of extensive and pan-drug resistant bacteria there are few antibiotics left to treat patients, thus novel RNA-based strategies are being considered. Here, we examine the current situation of different non-coding RNAs found in bacteria as well as their function and potential application as antimicrobial agents. Furthermore, we discuss the factors that may contribute in the efficient development of RNA-based drugs, the limitations for their implementation and the use of nanocarriers for delivery.
Collapse
Affiliation(s)
- Gisela Parmeciano Di Noto
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| | - María Carolina Molina
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| | - Cecilia Quiroga
- Universidad de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Tecnológicas, Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPAM), Facultad de Medicina, Buenos Aires, Argentina
| |
Collapse
|
11
|
Abstract
The study of bacteriophages (phages) and prophages has provided key insights into almost every cellular process as well as led to the discovery of unexpected new mechanisms and the development of valuable tools. This is exemplified for RNA-based regulation. For instance, the characterization and exploitation of the antiphage CRISPR (clustered regularly interspaced short palindromic repeat) systems is revolutionizing molecular biology. Phage-encoded proteins such as the RNA-binding MS2 protein, which is broadly used to isolate tagged RNAs, also have been developed as valuable tools. Hfq, the RNA chaperone protein central to the function of many base-pairing small RNAs (sRNAs), was first characterized as a bacterial host factor required for Qβ phage replication. The ongoing studies of RNAs are continuing to reveal regulatory connections between infecting phages, prophages, and bacteria and to provide novel insights. There are bacterial and prophage sRNAs that regulate prophage genes, which impact bacterial virulence as well as bacterial cell killing. Conversely, phage- and prophage-encoded sRNAs modulate the expression of bacterial genes modifying metabolism. An interesting subcategory of the prophage-encoded sRNAs are sponge RNAs that inhibit the activities of bacterial-encoded sRNAs. Phages also affect posttranscriptional regulation in bacteria through proteins that inhibit or alter the activities of key bacterial proteins involved in posttranscriptional regulation. However, what is most exciting about phage and prophage research, given the millions of phage-encoded genes that have not yet been characterized, is the vast potential for discovering new RNA regulators and novel mechanisms and for gaining insight into the evolution of regulatory RNAs.
Collapse
|
12
|
Wang D, McAteer SP, Wawszczyk AB, Russell CD, Tahoun A, Elmi A, Cockroft SL, Tollervey D, Granneman S, Tree JJ, Gally DL. An RNA-dependent mechanism for transient expression of bacterial translocation filaments. Nucleic Acids Res 2018; 46:3366-3381. [PMID: 29432565 PMCID: PMC5909449 DOI: 10.1093/nar/gky096] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Revised: 01/28/2018] [Accepted: 02/06/2018] [Indexed: 12/31/2022] Open
Abstract
The prokaryotic RNA chaperone Hfq mediates sRNA-mRNA interactions and plays a significant role in post-transcriptional regulation of the type III secretion (T3S) system produced by a range of Escherichia coli pathotypes. UV-crosslinking was used to map Hfq-binding under conditions that promote T3S and multiple interactions were identified within polycistronic transcripts produced from the locus of enterocyte effacement (LEE) that encodes the T3S system. The majority of Hfq binding was within the LEE5 and LEE4 operons, the latter encoding the translocon apparatus (SepL-EspADB) that is positively regulated by the RNA binding protein, CsrA. Using the identified Hfq-binding sites and a series of sRNA deletions, the sRNA Spot42 was shown to directly repress translation of LEE4 at the sepL 5' UTR. In silico and in vivo analyses of the sepL mRNA secondary structure combined with expression studies of truncates indicated that the unbound sepL mRNA is translationally inactive. Based on expression studies with site-directed mutants, an OFF-ON-OFF toggle model is proposed that results in transient translation of SepL and EspA filament assembly. Under this model, the nascent mRNA is translationally off, before being activated by CsrA, and then repressed by Hfq and Spot42.
Collapse
Affiliation(s)
- Dai Wang
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, South Xiangan Rd., Xiangan District, Xiamen, Fujian Province 361102, China
| | - Sean P McAteer
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Agata B Wawszczyk
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Clark D Russell
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
| | - Amin Tahoun
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
- Faculty of Veterinary Medicine, Kafrelsheikh University, 33516 Kafrel-Sheikh, Egypt
| | - Alex Elmi
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - Scott L Cockroft
- EaStCHEM School of Chemistry, University of Edinburgh, Joseph Black Building, David Brewster Road, Edinburgh EH9 3FJ, UK
| | - David Tollervey
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Sander Granneman
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Jai J Tree
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney 2052, NSW, Australia
| | - David L Gally
- Division of Infection and Immunity, The Roslin Institute and R(D)SVS, University of Edinburgh, Edinburgh EH25 9RG, UK
| |
Collapse
|
13
|
Hör J, Gorski SA, Vogel J. Bacterial RNA Biology on a Genome Scale. Mol Cell 2018; 70:785-799. [PMID: 29358079 DOI: 10.1016/j.molcel.2017.12.023] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 12/11/2017] [Accepted: 12/22/2017] [Indexed: 12/16/2022]
Abstract
Bacteria are an exceedingly diverse group of organisms whose molecular exploration is experiencing a renaissance. While the classical view of bacterial gene expression was relatively simple, the emerging view is more complex, encompassing extensive post-transcriptional control involving riboswitches, RNA thermometers, and regulatory small RNAs (sRNAs) associated with the RNA-binding proteins CsrA, Hfq, and ProQ, as well as CRISPR/Cas systems that are programmed by RNAs. Moreover, increasing interest in members of the human microbiota and environmental microbial communities has highlighted the importance of understudied bacterial species with largely unknown transcriptome structures and RNA-based control mechanisms. Collectively, this creates a need for global RNA biology approaches that can rapidly and comprehensively analyze the RNA composition of a bacterium of interest. We review such approaches with a focus on RNA-seq as a versatile tool to investigate the different layers of gene expression in which RNA is made, processed, regulated, modified, translated, and turned over.
Collapse
Affiliation(s)
- Jens Hör
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Stanislaw A Gorski
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany
| | - Jörg Vogel
- Institute of Molecular Infection Biology, University of Würzburg, 97080 Würzburg, Germany; Helmholtz Institute for RNA-based Infection Research (HIRI), 97080 Würzburg, Germany.
| |
Collapse
|
14
|
Soutourina O. RNA-based control mechanisms of Clostridium difficile. Curr Opin Microbiol 2017; 36:62-68. [PMID: 28214735 DOI: 10.1016/j.mib.2017.01.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/28/2016] [Accepted: 01/08/2017] [Indexed: 01/05/2023]
Abstract
Clostridium difficile (CD)-associated diarrhoea is currently the most prevalent nosocomial diarrhoea worldwide. Many characteristics of CD pathogenicity remain poorly understood. Recent data strongly indicate the importance of an RNA network for the control of gene expression in CD. More than 200 regulatory RNAs have been identified by deep sequencing and targeted approaches, including Hfq-dependent trans riboregulators, cis-antisense RNAs, CRISPR RNAs, and c-di-GMP-responsive riboswitches. These regulatory RNAs are involved in the control of major processes in the CD infection cycle, for example motility, biofilm formation, adhesion, sporulation, stress response, and defence against bacteriophages. We will discuss recent advances in elucidation of the original features of RNA-based mechanisms in this important enteropathogen. This knowledge may pave the way for further discoveries in this emergent field.
Collapse
Affiliation(s)
- Olga Soutourina
- Laboratoire Pathogenèse des Bactéries Anaérobies, Institut Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, France; Université Paris Diderot, Sorbonne Paris Cité, Cellule Pasteur, 25 rue du Dr Roux, 75724 Paris Cedex 15, France; Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, 91198, Gif-sur-Yvette cedex, France.
| |
Collapse
|
15
|
Ma J, Pan Z, Huang J, Sun M, Lu C, Yao H. The Hcp proteins fused with diverse extended-toxin domains represent a novel pattern of antibacterial effectors in type VI secretion systems. Virulence 2017; 8:1189-1202. [PMID: 28060574 DOI: 10.1080/21505594.2017.1279374] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
The type VI secretion system (T6SS) is a widespread molecular weapon deployed by many bacterial species to target eukaryotic host cells or rival bacteria. Using a dynamic injection mechanism, diverse effectors can be delivered by T6SS directly into recipient cells. Here, we report a new family of T6SS effectors encoded by extended Hcps carrying diverse toxin domains. Bioinformatic analyses revealed that these Hcps with C-terminal extension toxins, designated as Hcp-ET, exist widely in the Enterobacteriaceae. To verify our findings, Hcp-ET1 was tested for its antibacterial effect, and showed effective inhibition of target cell growth via the predicted HNH-DNase activity by T6SS-dependent delivery. Further studies showed that Hcp-ET2 mediated interbacterial antagonism via a Tle1 phospholipase (encoded by DUF2235 domain) activity. Notably, comprehensive analyses of protein homology and genomic neighborhoods revealed that Hcp-ET3-4 is fused with 2 toxin domains (Pyocin S3 and Colicin-DNase) C-terminally, and its encoding gene is followed 3 duplications of the cognate immunity genes. However, some bacteria encode a separated hcp-et3 and an orphan et4 (et4O1) genes caused by a termination-codon mutation in the fusion region between Pyocin S3 and Colicin-DNase encoding fragments. Our results demonstrated that both of these toxins had antibacterial effects. Further, all duplications of the cognate immunity protein contributed to neutralize the DNase toxicity of Pyocin S3 and Colicin, which has not been reported previously. In conclusion, we propose that Hcp-ET proteins are polymorphic T6SS effectors, and thus present a novel encoding pattern of T6SS effectors.
Collapse
Affiliation(s)
- Jiale Ma
- a Department of Veterinary Microbiology and Immunology, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing , China.,b Key Lab of Animal Bacteriology, Ministry of Agriculture , Nanjing , China
| | - Zihao Pan
- a Department of Veterinary Microbiology and Immunology, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing , China.,b Key Lab of Animal Bacteriology, Ministry of Agriculture , Nanjing , China
| | - Jinhu Huang
- a Department of Veterinary Microbiology and Immunology, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing , China.,b Key Lab of Animal Bacteriology, Ministry of Agriculture , Nanjing , China
| | - Min Sun
- a Department of Veterinary Microbiology and Immunology, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing , China.,b Key Lab of Animal Bacteriology, Ministry of Agriculture , Nanjing , China
| | - Chengping Lu
- a Department of Veterinary Microbiology and Immunology, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing , China.,b Key Lab of Animal Bacteriology, Ministry of Agriculture , Nanjing , China
| | - Huochun Yao
- a Department of Veterinary Microbiology and Immunology, College of Veterinary Medicine, Nanjing Agricultural University , Nanjing , China.,b Key Lab of Animal Bacteriology, Ministry of Agriculture , Nanjing , China
| |
Collapse
|
16
|
Kröger C, Kary SC, Schauer K, Cameron ADS. Genetic Regulation of Virulence and Antibiotic Resistance in Acinetobacter baumannii. Genes (Basel) 2016; 8:genes8010012. [PMID: 28036056 PMCID: PMC5295007 DOI: 10.3390/genes8010012] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 12/18/2016] [Accepted: 12/20/2016] [Indexed: 01/14/2023] Open
Abstract
Multidrug resistant microorganisms are forecast to become the single biggest challenge to medical care in the 21st century. Over the last decades, members of the genus Acinetobacter have emerged as bacterial opportunistic pathogens, in particular as challenging nosocomial pathogens because of the rapid evolution of antimicrobial resistances. Although we lack fundamental biological insight into virulence mechanisms, an increasing number of researchers are working to identify virulence factors and to study antibiotic resistance. Here, we review current knowledge regarding the regulation of virulence genes and antibiotic resistance in Acinetobacter baumannii. A survey of the two-component systems AdeRS, BaeSR, GacSA and PmrAB explains how each contributes to antibiotic resistance and virulence gene expression, while BfmRS regulates cell envelope structures important for pathogen persistence. A. baumannii uses the transcription factors Fur and Zur to sense iron or zinc depletion and upregulate genes for metal scavenging as a critical survival tool in an animal host. Quorum sensing, nucleoid-associated proteins, and non-classical transcription factors such as AtfA and small regulatory RNAs are discussed in the context of virulence and antibiotic resistance.
Collapse
Affiliation(s)
- Carsten Kröger
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland.
| | - Stefani C Kary
- Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin 2, Ireland.
| | - Kristina Schauer
- Department of Veterinary Science, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität München, Oberschleißheim 85764, Germany.
| | - Andrew D S Cameron
- Department of Biology, University of Regina, Regina, SK S4S 042, Canada.
| |
Collapse
|
17
|
Fröhlich KS, Haneke K, Papenfort K, Vogel J. The target spectrum of SdsR small RNA in Salmonella. Nucleic Acids Res 2016; 44:10406-10422. [PMID: 27407104 PMCID: PMC5137417 DOI: 10.1093/nar/gkw632] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 06/11/2016] [Accepted: 06/29/2016] [Indexed: 12/28/2022] Open
Abstract
Model enteric bacteria such as Escherichia coli and Salmonella enterica express hundreds of small non-coding RNAs (sRNAs), targets for most of which are yet unknown. Some sRNAs are remarkably well conserved, indicating that they serve cellular functions that go beyond the necessities of a single species. One of these ‘core sRNAs’ of largely unknown function is the abundant ∼100-nucleotide SdsR sRNA which is transcribed by the general stress σ-factor, σS and accumulates in stationary phase. In Salmonella, SdsR was known to inhibit the synthesis of the species-specific porin, OmpD. However, sdsR genes are present in almost all enterobacterial genomes, suggesting that additional, conserved targets of this sRNA must exist. Here, we have combined SdsR pulse-expression with whole genome transcriptomics to discover 20 previously unknown candidate targets of SdsR which include mRNAs coding for physiologically important regulators such as the carbon utilization regulator, CRP, the nucleoid-associated chaperone, StpA and the antibiotic resistance transporter, TolC. Processing of SdsR by RNase E results in two cellular SdsR variants with distinct target spectra. While the overall physiological role of this orphan core sRNA remains to be fully understood, the new SdsR targets present valuable leads to determine sRNA functions in resting bacteria.
Collapse
Affiliation(s)
- Kathrin S Fröhlich
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, D-97080 Würzburg, Germany.,Department of Biology I, Microbiology, Ludwig-Maximilians-University Munich, D-82152 Martinsried, Germany
| | - Katharina Haneke
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, D-97080 Würzburg, Germany
| | - Kai Papenfort
- Department of Biology I, Microbiology, Ludwig-Maximilians-University Munich, D-82152 Martinsried, Germany
| | - Jörg Vogel
- RNA Biology Group, Institute for Molecular Infection Biology, University of Würzburg, Josef-Schneider-Straße 2, D-97080 Würzburg, Germany
| |
Collapse
|