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Al Ali A, Alsulami J, Aubee JI, Idowu A, Tomlinson BR, Felton EA, Jackson JK, Kennedy SJ, Torres NJ, Shaw LN, Thompson KM. Staphylococcus aureus SigS Induces Expression of a Regulatory Protein Pair That Modulates Its mRNA Stability. J Bacteriol 2023; 205:e0039222. [PMID: 37255480 PMCID: PMC10294688 DOI: 10.1128/jb.00392-22] [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: 10/17/2022] [Accepted: 04/13/2023] [Indexed: 06/01/2023] Open
Abstract
SigS is the sole extracytoplasmic function sigma factor in Staphylococcus aureus and is necessary for virulence, immune evasion, and adaptation to toxic chemicals and environmental stressors. Despite the contribution of SigS to a myriad of critical phenotypes, the downstream effectors of SigS-dependent pathogenesis, immune evasion, and stress adaptation remain elusive. To address this knowledge gap, we analyzed the S. aureus transcriptome following transient overexpression of SigS. We identified a bicistronic transcript, upregulated 1,000-fold, containing two midsized genes, each containing single domains of unknown function (DUFs). We renamed these genes SigS-regulated orfA (sroA) and SigS-regulated orfB (sroB). We demonstrated that SigS regulation of the sroAB operon is direct by using in vitro transcription analysis. Using Northern blot analysis, we also demonstrated that SroA and SroB have opposing autoregulatory functions on the transcriptional architecture of the sigS locus, with SroA stimulating SigS mRNA levels and SroB stimulating s750 (SigS antisense) levels. We hypothesized that these opposing regulatory effects were due to a direct interaction. We subsequently demonstrated a direct interaction between SroA and SroB using an in vivo surrogate genetics approach via bacterial adenylate cyclase-based two-hybrid (BACTH) analysis. We demonstrated that the SroA effect on SigS is at the posttranscriptional level of mRNA stability, highlighting a mechanism likely used by S. aureus to tightly control SigS levels. Finally, we demonstrate that the sroAB locus promotes virulence in a murine pneumonia model of infection. IMPORTANCE SigS is necessary for S. aureus virulence, immune evasion, and adaptation to chemical and environmental stressors. These processes are critically important for the ability of S. aureus to cause disease. However, the SigS-dependent transcriptome has not been identified, hindering our ability to identify downstream effectors of SigS that contribute to these pathogenic and adaptive phenotypes. Here, we identify a regulatory protein pair that is a major direct target of SigS, known as SroA and SroB. SroA also acts to stimulate SigS expression at the posttranscriptional level of RNA turnover, providing insight into intrinsically low levels of SigS. The discovery of SroA and SroB increases our understanding of SigS and the S. aureus pathogenesis process.
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Affiliation(s)
- Amer Al Ali
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
| | - Jamilah Alsulami
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
| | - Joseph I. Aubee
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
| | - Ayotimofe Idowu
- Department of Biology, College of Arts and Sciences, Howard University, Washington, DC, USA
| | - Brooke R. Tomlinson
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Emily A. Felton
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Jessica K. Jackson
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Sarah J. Kennedy
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Nathanial J. Torres
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Lindsey N. Shaw
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Karl M. Thompson
- Department of Microbiology, College of Medicine, Howard University, Washington, DC, USA
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The Small RNA Teg41 Is a Pleiotropic Regulator of Virulence in Staphylococcus aureus. Infect Immun 2022; 90:e0023622. [PMID: 36214557 PMCID: PMC9670889 DOI: 10.1128/iai.00236-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Previously, our group demonstrated a role for the small RNA (sRNA) Teg41 in regulating production of the alpha phenol-soluble modulin toxins (αPSMs) in Staphylococcus aureus. Overexpressing Teg41 increased αPSM production while deleting the 3' end of Teg41 (Teg41Δ3' strain) resulted in a decrease in αPSM production, reduced hemolytic activity of S. aureus culture supernatants, and attenuated virulence in a murine abscess model of infection. In this study, we further explore the attenuation of virulence in the Teg41Δ3' strain. Using both localized and systemic models of infection, we demonstrate that the Teg41Δ3' strain is more severely attenuated than an ΔαPSM mutant, strongly suggesting that Teg41 influences more than the αPSMs. Proteomic and transcriptomic analysis of the wild-type and Teg41Δ3' strains reveals widespread alterations in transcript abundance and protein production in the absence of Teg41, confirming that Teg41 has pleiotropic effects in the cell. We go on to investigate the molecular mechanism underlying Teg41-mediated gene regulation. Surprisingly, results demonstrate that certain Teg41 target genes, including the αPSMs and βPSMs, are transcriptionally altered in the Teg41Δ3' strain, while other targets, specifically spa (encoding surface protein A), are regulated at the level of transcript stability. Collectively, these data demonstrate that Teg41 is a pleiotropic RNA regulator in S. aureus that influences expression of a variety of genes using multiple different mechanisms.
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Menard G, Silard C, Suriray M, Rouillon A, Augagneur Y. Thirty Years of sRNA-Mediated Regulation in Staphylococcus aureus: From Initial Discoveries to In Vivo Biological Implications. Int J Mol Sci 2022; 23:ijms23137346. [PMID: 35806357 PMCID: PMC9266662 DOI: 10.3390/ijms23137346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Staphylococcus aureus is a widespread livestock and human pathogen that colonizes diverse microenvironments within its host. Its adaptation to the environmental conditions encountered within humans relies on coordinated gene expression. This requires a sophisticated regulatory network, among which regulatory RNAs (usually called sRNAs) have emerged as key players over the last 30 years. In S. aureus, sRNAs regulate target genes at the post-transcriptional level through base–pair interactions. The functional characterization of a subset revealed that they participate in all biological processes, including virulence, metabolic adaptation, and antibiotic resistance. In this review, we report 30 years of S. aureus sRNA studies, from their discovery to the in-depth characterizations of some of them. We also discuss their actual in vivo contribution, which is still lagging behind, and their place within the complex regulatory network. These shall be key aspects to consider in order to clearly uncover their in vivo biological functions.
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Affiliation(s)
- Guillaume Menard
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Chloé Silard
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Marie Suriray
- CHU Rennes, INSERM, BRM (Bacterial Regulatory RNAs and Medicine), SB2H (Service de Bactériologie Hygiène-Hospitalière), University Rennes, UMR_S 1230, F-35000 Rennes, France; (G.M.); (M.S.)
| | - Astrid Rouillon
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
| | - Yoann Augagneur
- INSERM, BRM (Bacterial Regulatory RNAs and Medicine), University Rennes, UMR_S 1230, F-35000 Rennes, France; (C.S.); (A.R.)
- Correspondence: ; Tel.: +33-223234631
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Subramanian D, Natarajan J. Leveraging big data bioinformatics approaches to extract knowledge from Staphylococcus aureus public omics data. Crit Rev Microbiol 2022; 49:391-413. [PMID: 35468027 DOI: 10.1080/1040841x.2022.2065905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Staphylococcus aureus is a notorious pathogen posing challenges in the medical industry due to drug resistance and biofilm formation. The horizon of knowledge on S. aureus pathogenesis has expanded with the advancement of data-driven bioinformatics techniques. Mining information from sequenced genomes and their expression data is an economic approach that alleviates wastage of resources and redundancy in experiments. The current review covers how big data bioinformatics has been used in the analysis of S. aureus from publicly available -omics data to uncover mechanisms of infection and inhibition. Particularly, advances in the past two decades in biomarker discovery, host responses, phenotype identification, consolidation of information, and drug development are discussed highlighting the challenges and shortcomings. Overall, the review summarizes the diverse aspects of scrupulous re-analysis of S. aureus proteomic and transcriptomic expression datasets retrieved from public repositories in terms of the efforts taken, benefits offered, and follow-up actions. The detailed review thus serves as a reference and aid for (i) Computational biologists by briefing the approaches utilized for bacterial omics re-analysis concerning S. aureus and (ii) Experimental biologists by elucidating the potential of bioinformatics in biological research to generate reliable postulates in a prompt and economical manner.
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Affiliation(s)
- Devika Subramanian
- Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, India
| | - Jeyakumar Natarajan
- Data Mining and Text Mining Laboratory, Department of Bioinformatics, Bharathiar University, Coimbatore, India
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Regulation of Heterogenous LexA Expression in Staphylococcus aureus by an Antisense RNA Originating from Transcriptional Read-Through upon Natural Mispairings in the sbrB Intrinsic Terminator. Int J Mol Sci 2022; 23:ijms23010576. [PMID: 35009002 PMCID: PMC8745188 DOI: 10.3390/ijms23010576] [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] [Received: 12/09/2021] [Revised: 12/30/2021] [Accepted: 01/01/2022] [Indexed: 12/10/2022] Open
Abstract
Bacterial genomes are pervasively transcribed, generating a wide variety of antisense RNAs (asRNAs). Many of them originate from transcriptional read-through events (TREs) during the transcription termination process. Previous transcriptome analyses revealed that the lexA gene from Staphylococcus aureus, which encodes the main SOS response regulator, is affected by the presence of an asRNA. Here, we show that the lexA antisense RNA (lexA-asRNA) is generated by a TRE on the intrinsic terminator (TTsbrB) of the sbrB gene, which is located downstream of lexA, in the opposite strand. Transcriptional read-through occurs by a natural mutation that destabilizes the TTsbrB structure and modifies the efficiency of the intrinsic terminator. Restoring the mispairing mutation in the hairpin of TTsbrB prevented lexA-asRNA transcription. The level of lexA-asRNA directly correlated with cellular stress since the expressions of sbrB and lexA-asRNA depend on the stress transcription factor SigB. Comparative analyses revealed strain-specific nucleotide polymorphisms within TTsbrB, suggesting that this TT could be prone to accumulating natural mutations. A genome-wide analysis of TREs suggested that mispairings in TT hairpins might provide wider transcriptional connections with downstream genes and, ultimately, transcriptomic variability among S. aureus strains.
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Barrientos L, Mercier N, Lalaouna D, Caldelari I. Assembling the Current Pieces: The Puzzle of RNA-Mediated Regulation in Staphylococcus aureus. Front Microbiol 2021; 12:706690. [PMID: 34367109 PMCID: PMC8334554 DOI: 10.3389/fmicb.2021.706690] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 06/30/2021] [Indexed: 01/16/2023] Open
Abstract
The success of the major opportunistic human Staphylococcus aureus relies on the production of numerous virulence factors, which allow rapid colonization and dissemination in any tissues. Indeed, regulation of its virulence is multifactorial, and based on the production of transcriptional factors, two-component systems (TCS) and small regulatory RNAs (sRNAs). Advances in high-throughput sequencing technologies have unveiled the existence of hundreds of potential RNAs with regulatory functions, but only a fraction of which have been validated in vivo. These discoveries have modified our thinking and understanding of bacterial physiology and virulence fitness by placing sRNAs, alongside transcriptional regulators, at the center of complex and intertwined regulatory networks that allow S. aureus to rapidly adapt to the environmental cues present at infection sites. In this review, we describe the recently acquired knowledge of characterized regulatory RNAs in S. aureus that are associated with metal starvation, nutrient availability, stress responses and virulence. These findings highlight the importance of sRNAs for the comprehension of S. aureus infection processes while raising questions about the interplay between these key regulators and the pathways they control.
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Affiliation(s)
- Laura Barrientos
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France
| | - Noémie Mercier
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France
| | - David Lalaouna
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France
| | - Isabelle Caldelari
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, Strasbourg, France
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Sinha D, Sinha D, Dutta A, Chakraborty T, Mondal R, Seal S, Poddar A, Chatterjee S, Sau S. Alternative Sigma Factor of Staphylococcus aureus Interacts with the Cognate Antisigma Factor Primarily Using Its Domain 3. Biochemistry 2021; 60:135-151. [PMID: 33406357 DOI: 10.1021/acs.biochem.0c00881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
σB, an alternative sigma factor, is usually employed to tackle the general stress response in Staphylococcus aureus and other Gram-positive bacteria. This protein, involved in S. aureus-mediated pathogenesis, is typically blocked by RsbW, an antisigma factor having serine kinase activity. σB, a σ70-like sigma factor, harbors three conserved domains designated σB2, σB3, and σB4. To better understand the interaction between RsbW and σB or its domains, we have studied their recombinant forms, rRsbW, rσB, rσB2, rσB3, and rσB4, using different probes. The results show that none of the rσB domains, unlike rσB, showed binding to a cognate DNA in the presence of a core RNA polymerase. However, both rσB2 and rσB3, like rσB, interacted with rRsbW, and the order of their rRsbW binding affinity looks like rσB > rσB3 > rσB2. Furthermore, the reaction between rRsbW and rσB or rσB3 was exothermic and occurred spontaneously. rRsbW and rσB3 also associate with each other at a stoichiometry of 2:1, and different types of noncovalent bonds might be responsible for their interaction. A structural model of the RsbW-σB3 complex that has supported our experimental results indicated the binding of rσB3 at the putative dimeric interface of RsbW. A genetic study shows that the tentative dimer-forming region of RsbW is crucial for preserving its rσB binding ability, serine kinase activity, and dimerization ability. Additionally, a urea-induced equilibrium unfolding study indicated a notable thermodynamic stabilization of σB3 in the presence of RsbW. Possible implications of the stabilization data in drug discovery were discussed at length.
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Affiliation(s)
- Debabrata Sinha
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal 700054, India
| | - Debasmita Sinha
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal 700054, India
| | - Anindya Dutta
- Department of Biophysics, Bose Institute, Kolkata, West Bengal 700054, India
| | - Tushar Chakraborty
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal 700054, India
| | - Rajkrishna Mondal
- Department of Biotechnology, Nagaland University, Dimapur, Nagaland 797112, India
| | - Soham Seal
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal 700054, India
| | - Asim Poddar
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal 700054, India
| | | | - Subrata Sau
- Department of Biochemistry, Bose Institute, Kolkata, West Bengal 700054, India
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8
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Augagneur Y, King AN, Germain-Amiot N, Sassi M, Fitzgerald JW, Sahukhal GS, Elasri MO, Felden B, Brinsmade SR. Analysis of the CodY RNome reveals RsaD as a stress-responsive riboregulator of overflow metabolism in Staphylococcus aureus. Mol Microbiol 2019; 113:309-325. [PMID: 31696578 DOI: 10.1111/mmi.14418] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2019] [Indexed: 11/28/2022]
Abstract
In Staphylococcus aureus, the transcription factor CodY modulates the expression of hundreds of genes, including most virulence factors, in response to the availability of key nutrients like GTP and branched-chain amino acids. Despite numerous studies examining how CodY controls gene expression directly or indirectly, virtually nothing is known about the extent to which CodY exerts its effect through small regulatory RNAs (sRNAs). Herein, we report the first set of sRNAs under the control of CodY. We reveal that staphylococcal sRNA RsaD is overexpressed >20-fold in a CodY-deficient strain in three S. aureus clinical isolates and in S. epidermidis. We validated the CodY-dependent regulation of rsaD and demonstrated that CodY directly represses rsaD expression by binding the promoter. Using a combination of molecular techniques, we show that RsaD posttranscriptionally regulates alsS (acetolactate synthase) mRNA and enzyme levels. We further show that RsaD redirects carbon overflow metabolism, contributing to stationary phase cell death during exposure to weak acid stress. Taken together, our data delineate a role for CodY in controlling sRNA expression in a major human pathogen and indicate that RsaD may integrate nutrient depletion and other signals to mount a response to physiological stress experienced by S. aureus in diverse environments.
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Affiliation(s)
- Yoann Augagneur
- INSERM U1230 Biochimie Pharmaceutique, Université de Rennes I, Rennes, France
| | - Alyssa N King
- Department of Biology, Georgetown University, Washington, DC, USA
| | | | - Mohamed Sassi
- INSERM U1230 Biochimie Pharmaceutique, Université de Rennes I, Rennes, France
| | | | - Gyan S Sahukhal
- Center of Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, USA
| | - Mohamed O Elasri
- Center of Molecular and Cellular Biosciences, The University of Southern Mississippi, Hattiesburg, MS, USA
| | - Brice Felden
- INSERM U1230 Biochimie Pharmaceutique, Université de Rennes I, Rennes, France
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Lalaouna D, Baude J, Wu Z, Tomasini A, Chicher J, Marzi S, Vandenesch F, Romby P, Caldelari I, Moreau K. RsaC sRNA modulates the oxidative stress response of Staphylococcus aureus during manganese starvation. Nucleic Acids Res 2019; 47:9871-9887. [PMID: 31504767 PMCID: PMC6765141 DOI: 10.1093/nar/gkz728] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 07/22/2019] [Accepted: 08/19/2019] [Indexed: 02/07/2023] Open
Abstract
The human opportunistic pathogen Staphylococcus aureus produces numerous small regulatory RNAs (sRNAs) for which functions are still poorly understood. Here, we focused on an atypical and large sRNA called RsaC. Its length varies between different isolates due to the presence of repeated sequences at the 5′ end while its 3′ part is structurally independent and highly conserved. Using MS2-affinity purification coupled with RNA sequencing (MAPS) and quantitative differential proteomics, sodA mRNA was identified as a primary target of RsaC sRNA. SodA is a Mn-dependent superoxide dismutase involved in oxidative stress response. Remarkably, rsaC gene is co-transcribed with the major manganese ABC transporter MntABC and, consequently, RsaC is mainly produced in response to Mn starvation. This 3′UTR-derived sRNA is released from mntABC-RsaC precursor after cleavage by RNase III. The mature and stable form of RsaC inhibits the synthesis of the Mn-containing enzyme SodA synthesis and favors the oxidative stress response mediated by SodM, an alternative SOD enzyme using either Mn or Fe as co-factor. In addition, other putative targets of RsaC are involved in oxidative stress (ROS and NOS) and metal homeostasis (Fe and Zn). Consequently, RsaC may balance two interconnected defensive responses, i.e. oxidative stress and metal-dependent nutritional immunity.
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Affiliation(s)
- David Lalaouna
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Jessica Baude
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon1, Ecole Normale Supérieure de Lyon, CNRS UMR5308, Lyon, France
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Arnaud Tomasini
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Johana Chicher
- Plateforme protéomique Strasbourg-Esplanade, IBMC-CNRS, Strasbourg, France
| | - Stefano Marzi
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - François Vandenesch
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon1, Ecole Normale Supérieure de Lyon, CNRS UMR5308, Lyon, France.,Centre National de Référence des Staphylocoques, Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
| | - Pascale Romby
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Isabelle Caldelari
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | - Karen Moreau
- CIRI, Centre International de Recherche en Infectiologie, Inserm U1111, Université Lyon1, Ecole Normale Supérieure de Lyon, CNRS UMR5308, Lyon, France
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Abstract
Regulatory RNAs, present in many bacterial genomes and particularly in pathogenic bacteria such as Staphylococcus aureus, control the expression of genes encoding virulence factors or metabolic proteins. They are extremely diverse and include noncoding RNAs (sRNA), antisense RNAs, and some 5' or 3' untranslated regions of messenger RNAs that act as sensors for metabolites, tRNAs, or environmental conditions (e.g., temperature, pH). In this review we focus on specific examples of sRNAs of S. aureus that illustrate how numerous sRNAs and associated proteins are embedded in complex networks of regulation. In addition, we discuss the CRISPR-Cas systems defined as an RNA-interference-like mechanism, which also exist in staphylococcal strains.
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11
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Zhang P, Wright JA, Tymon A, Nair SP. Bicarbonate induces high-level resistance to the human antimicrobial peptide LL-37 in Staphylococcus aureus small colony variants. J Antimicrob Chemother 2019; 73:615-619. [PMID: 29211886 PMCID: PMC5890704 DOI: 10.1093/jac/dkx433] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 10/25/2017] [Indexed: 01/29/2023] Open
Abstract
Objectives Staphylococcus aureus small colony variants (SCVs) cause persistent infections and are resistant to cationic antibiotics. Antimicrobial peptides (AMPs) have been suggested as promising alternatives for treating antibiotic-resistant bacteria. We investigated the capacity of the human cationic AMP LL-37 to kill SCVs in the presence of physiological concentrations of bicarbonate, which are reported to alter bacterial membrane permeability and change resistance of bacteria to AMPs. Methods MBCs of LL-37 for S. aureus SCVs with mutations in different genes in the presence and absence of bicarbonate were determined. Results In the absence of bicarbonate, SCVs of S. aureus strains LS-1 and 8325-4 had the same level of resistance to LL-37 as the parental strain (8 mg/L). In the presence of bicarbonate, hemB, menD and aroD SCVs of LS-1 had high-level resistance to LL-37 (≥128 mg/L) compared with the parental strain (16 mg/L). However, only the aroD SCV of strain 8324-5 showed high-level resistance. 8325-4 harbours mutations in two genes, tcaR and rsbU, which are involved in antimicrobial sensing and the stress response, respectively. When rsbU was repaired in 8325-4 it displayed high-level resistance to LL-37 in the presence of bicarbonate. This phenotype was lost when tcaR was also repaired, demonstrating that RsbU and TcaR are involved in LL-37 resistance in the presence of bicarbonate Conclusions S. aureus SCVs would be resistant to high concentrations of LL-37 in niches where there are physiological concentrations of bicarbonate and therefore this AMP may not be effective in combating SCVs.
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Affiliation(s)
- Ping Zhang
- Department of Microbial Diseases, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - John A Wright
- Immunology Catalyst, GSK, Stevenage, Hertfordshire, UK
| | - Anna Tymon
- Department of Microbial Diseases, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
| | - Sean P Nair
- Department of Microbial Diseases, UCL Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK
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Khitun A, Ness TJ, Slavoff SA. Small open reading frames and cellular stress responses. Mol Omics 2019; 15:108-116. [PMID: 30810554 DOI: 10.1039/c8mo00283e] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Small open reading frames (smORFs) encoding polypeptides of less than 100 amino acids in eukaryotes (50 amino acids in prokaryotes) were historically excluded from genome annotation. However, recent advances in genomics, ribosome footprinting, and proteomics have revealed thousands of translated smORFs in genomes spanning evolutionary space. These smORFs can encode functional polypeptides, or act as cis-translational regulators. Herein we review evidence that some smORF-encoded polypeptides (SEPs) participate in stress responses in both prokaryotes and eukaryotes, and that some upstream ORFs (uORFs) regulate stress-responsive translation of downstream cistrons in eukaryotic cells. These studies provide insight into a regulated subclass of smORFs and suggest that at least some SEPs may participate in maintenance of cellular homeostasis under stress.
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Affiliation(s)
- Alexandra Khitun
- Chemical Biology Institute, Yale University, West Haven, CT 06516, USA. and Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Travis J Ness
- Chemical Biology Institute, Yale University, West Haven, CT 06516, USA. and Department of Chemistry, Yale University, New Haven, CT 06520, USA
| | - Sarah A Slavoff
- Chemical Biology Institute, Yale University, West Haven, CT 06516, USA. and Department of Chemistry, Yale University, New Haven, CT 06520, USA and Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06520, USA
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13
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Abstract
Small regulatory RNAs are now recognized as key regulators of gene expression in bacteria. They accumulate under specific conditions, most often because their synthesis is directly controlled by transcriptional regulators, including but not limited to alternative sigma factors and response regulators of two-component systems. In turn, small RNAs regulate, mostly at the posttranscriptional level, expression of multiple genes, among which are genes encoding transcriptional regulators. Small RNAs are thus embedded in mixed regulatory circuits combining transcriptional and posttranscriptional controls, and whose properties are discussed here.
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14
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Liu W, Rochat T, Toffano-Nioche C, Le Lam TN, Bouloc P, Morvan C. Assessment of Bona Fide sRNAs in Staphylococcus aureus. Front Microbiol 2018. [PMID: 29515534 PMCID: PMC5826253 DOI: 10.3389/fmicb.2018.00228] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Bacterial regulatory RNAs have been extensively studied for over a decade, and are progressively being integrated into the complex genetic regulatory network. Transcriptomic arrays, recent deep-sequencing data and bioinformatics suggest that bacterial genomes produce hundreds of regulatory RNAs. However, while some have been authenticated, the existence of the others varies according to strains and growth conditions, and their detection fluctuates with the methodologies used for data acquisition and interpretation. For example, several small RNA (sRNA) candidates are now known to be parts of UTR transcripts. Accurate annotation of regulatory RNAs is a complex task essential for molecular and functional studies. We defined bona fide sRNAs as those that (i) likely act in trans and (ii) are not expressed from the opposite strand of a coding gene. Using published data and our own RNA-seq data, we reviewed hundreds of Staphylococcus aureus putative regulatory RNAs using the DETR'PROK computational pipeline and visual inspection of expression data, addressing the question of which transcriptional signals correspond to sRNAs. We conclude that the model strain HG003, a NCTC8325 derivative commonly used for S. aureus genetic regulation studies, has only about 50 bona fide sRNAs, indicating that these RNAs are less numerous than commonly stated. Among them, about half are associated to the S. aureus sp. core genome and a quarter are possibly expressed in other Staphylococci. We hypothesize on their features and regulation using bioinformatic approaches.
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Affiliation(s)
- Wenfeng Liu
- Institute for Integrative Biology of the Cell (I2BC), CEA, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Tatiana Rochat
- VIM, Institut National de la Recherche Agronomique, Université Paris-Saclay, Institut National de la Recherche Agronomique Centre Jouy-en-Josas, Jouy-en-Josas, France
| | - Claire Toffano-Nioche
- Institute for Integrative Biology of the Cell (I2BC), CEA, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Thao Nguyen Le Lam
- Institute for Integrative Biology of the Cell (I2BC), CEA, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Philippe Bouloc
- Institute for Integrative Biology of the Cell (I2BC), CEA, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Claire Morvan
- Institute for Integrative Biology of the Cell (I2BC), CEA, Centre National de la Recherche Scientifique, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
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15
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Broach WH, Weiss A, Shaw LN. Transcriptomic analysis of staphylococcal sRNAs: insights into species-specific adaption and the evolution of pathogenesis. Microb Genom 2016; 2:e000065. [PMID: 28348860 PMCID: PMC5343137 DOI: 10.1099/mgen.0.000065] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 04/22/2016] [Indexed: 12/26/2022] Open
Abstract
Next-generation sequencing technologies have dramatically increased the rate at which new genomes are sequenced. Accordingly, automated annotation programs have become adept at identifying and annotating protein coding regions, as well as common and conserved RNAs. Additionally, RNAseq techniques have advanced our ability to identify and annotate regulatory RNAs (sRNAs), which remain significantly understudied. Recently, our group catalogued and annotated all previously known and newly identified sRNAs in several Staphylococcus aureus strains. These complete annotation files now serve as tools to compare the sRNA content of S. aureus with other bacterial strains to investigate the conservation of their sRNomes. Accordingly, in this study we performed RNAseq on two staphylococcal species, Staphylococcus epidermidis and Staphylococcus carnosus, identifying 118 and 89 sRNAs in these organisms, respectively. The sRNA contents of all three species were then compared to elucidate their common and species-specific sRNA content, identifying a core set of between 53 and 36 sRNAs encoded in each organism. In addition, we determined that S. aureus has the largest set of unique sRNAs (137) while S. epidermidishas the fewest (25). Finally, we identify a highly conserved sequence and structural motif differentially represented within, yet common to, both S. aureus and S. epidermidis. Collectively, in this study, we uncover the sRNome common to three staphylococcal species, shedding light on sRNAs that are likely to be involved in basic physiological processes common to the genus. More significantly, we have identified species-specific sRNAs that are likely to influence the individual lifestyle and behaviour of these diverse staphylococcal strains.
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Affiliation(s)
- William H Broach
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Andy Weiss
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
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16
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Resilience in the Face of Uncertainty: Sigma Factor B Fine-Tunes Gene Expression To Support Homeostasis in Gram-Positive Bacteria. Appl Environ Microbiol 2016; 82:4456-4469. [PMID: 27208112 DOI: 10.1128/aem.00714-16] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Gram-positive bacteria are ubiquitous and diverse microorganisms that can survive and sometimes even thrive in continuously changing environments. The key to such resilience is the ability of members of a population to respond and adjust to dynamic conditions in the environment. In bacteria, such responses and adjustments are mediated, at least in part, through appropriate changes in the bacterial transcriptome in response to the conditions encountered. Resilience is important for bacterial survival in diverse, complex, and rapidly changing environments and requires coordinated networks that integrate individual, mechanistic responses to environmental cues to enable overall metabolic homeostasis. In many Gram-positive bacteria, a key transcriptional regulator of the response to changing environmental conditions is the alternative sigma factor σ(B) σ(B) has been characterized in a subset of Gram-positive bacteria, including the genera Bacillus, Listeria, and Staphylococcus Recent insight from next-generation-sequencing results indicates that σ(B)-dependent regulation of gene expression contributes to resilience, i.e., the coordination of complex networks responsive to environmental changes. This review explores contributions of σ(B) to resilience in Bacillus, Listeria, and Staphylococcus and illustrates recently described regulatory functions of σ(B).
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Carroll RK, Weiss A, Broach WH, Wiemels RE, Mogen AB, Rice KC, Shaw LN. Genome-wide Annotation, Identification, and Global Transcriptomic Analysis of Regulatory or Small RNA Gene Expression in Staphylococcus aureus. mBio 2016; 7:e01990-15. [PMID: 26861020 PMCID: PMC4752604 DOI: 10.1128/mbio.01990-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 12/22/2015] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED In Staphylococcus aureus, hundreds of small regulatory or small RNAs (sRNAs) have been identified, yet this class of molecule remains poorly understood and severely understudied. sRNA genes are typically absent from genome annotation files, and as a consequence, their existence is often overlooked, particularly in global transcriptomic studies. To facilitate improved detection and analysis of sRNAs in S. aureus, we generated updated GenBank files for three commonly used S. aureus strains (MRSA252, NCTC 8325, and USA300), in which we added annotations for >260 previously identified sRNAs. These files, the first to include genome-wide annotation of sRNAs in S. aureus, were then used as a foundation to identify novel sRNAs in the community-associated methicillin-resistant strain USA300. This analysis led to the discovery of 39 previously unidentified sRNAs. Investigating the genomic loci of the newly identified sRNAs revealed a surprising degree of inconsistency in genome annotation in S. aureus, which may be hindering the analysis and functional exploration of these elements. Finally, using our newly created annotation files as a reference, we perform a global analysis of sRNA gene expression in S. aureus and demonstrate that the newly identified tsr25 is the most highly upregulated sRNA in human serum. This study provides an invaluable resource to the S. aureus research community in the form of our newly generated annotation files, while at the same time presenting the first examination of differential sRNA expression in pathophysiologically relevant conditions. IMPORTANCE Despite a large number of studies identifying regulatory or small RNA (sRNA) genes in Staphylococcus aureus, their annotation is notably lacking in available genome files. In addition to this, there has been a considerable lack of cross-referencing in the wealth of studies identifying these elements, often leading to the same sRNA being identified multiple times and bearing multiple names. In this work, we have consolidated and curated known sRNA genes from the literature and mapped them to their position on the S. aureus genome, creating new genome annotation files. These files can now be used by the scientific community at large in experiments to search for previously undiscovered sRNA genes and to monitor sRNA gene expression by transcriptome sequencing (RNA-seq). We demonstrate this application, identifying 39 new sRNAs and studying their expression during S. aureus growth in human serum.
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Affiliation(s)
- Ronan K Carroll
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Andy Weiss
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - William H Broach
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Richard E Wiemels
- Department of Biological Sciences, Ohio University, Athens, Ohio, USA
| | - Austin B Mogen
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Kelly C Rice
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, Florida, USA
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18
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Andrey DO, Jousselin A, Villanueva M, Renzoni A, Monod A, Barras C, Rodriguez N, Kelley WL. Impact of the Regulators SigB, Rot, SarA and sarS on the Toxic Shock Tst Promoter and TSST-1 Expression in Staphylococcus aureus. PLoS One 2015; 10:e0135579. [PMID: 26275216 PMCID: PMC4537247 DOI: 10.1371/journal.pone.0135579] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 07/24/2015] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is an important pathogen manifesting virulence through diverse disease forms, ranging from acute skin infections to life-threatening bacteremia or systemic toxic shock syndromes. In the latter case, the prototypical superantigen is TSST-1 (Toxic Shock Syndrome Toxin 1), encoded by tst(H), and carried on a mobile genetic element that is not present in all S. aureus strains. Transcriptional regulation of tst is only partially understood. In this study, we dissected the role of sarA, sarS (sarH1), RNAIII, rot, and the alternative stress sigma factor sigB (σB). By examining tst promoter regulation predominantly in the context of its native sequence within the SaPI1 pathogenicity island of strain RN4282, we discovered that σB emerged as a particularly important tst regulator. We did not detect a consensus σB site within the tst promoter, and thus the effect of σB is likely indirect. We found that σB strongly repressed the expression of the toxin via at least two distinct regulatory pathways dependent upon sarA and agr. Furthermore rot, a member of SarA family, was shown to repress tst expression when overexpressed, although its deletion had no consistent measurable effect. We could not find any detectable effect of sarS, either by deletion or overexpression, suggesting that this regulator plays a minimal role in TSST-1 expression except when combined with disruption of sarA. Collectively, our results extend our understanding of complex multifactorial regulation of tst, revealing several layers of negative regulation. In addition to environmental stimuli thought to impact TSST-1 production, these findings support a model whereby sporadic mutation in a few key negative regulators can profoundly affect and enhance TSST-1 expression.
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Affiliation(s)
- Diego O. Andrey
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Ambre Jousselin
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - Maite Villanueva
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - Adriana Renzoni
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Antoinette Monod
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Christine Barras
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, CH-1211 Geneva 14, Switzerland
| | - Natalia Rodriguez
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
| | - William L. Kelley
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, CH-1211 Geneva, Switzerland
- * E-mail:
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19
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The Staphylococcus aureus protein-coding gene gdpS modulates sarS expression via mRNA-mRNA interaction. Infect Immun 2015; 83:3302-10. [PMID: 26056387 DOI: 10.1128/iai.00159-15] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/29/2015] [Indexed: 12/18/2022] Open
Abstract
Staphylococcus aureus is an important Gram-positive pathogen responsible for numerous diseases ranging from localized skin infections to life-threatening systemic infections. The virulence of S. aureus is essentially determined by a wide spectrum of factors, including cell wall-associated proteins and secreted toxins that are precisely controlled in response to environmental changes. GGDEF domain protein from Staphylococcus (GdpS) is the only conserved staphylococcal GGDEF domain protein that is involved not in c-di-GMP synthesis but in the virulence regulation of S. aureus NCTC8325. Our previous study showed that the inactivation of gdpS generates an extensive change of virulence factors together with, in particular, a major Spa (protein A) surface protein. As reported, sarS is a direct positive regulator of spa. The decreased transcript levels of sarS in the gdpS mutant compared with the parental NCTC8325 strain suggest that gdpS affects spa through interaction with sarS. In this study, site mutation and complementary experiments showed that the translation product of gdpS was not involved in the regulation of transcript levels of sarS. We found that gdpS functioned through direct RNA-RNA base pairing with the 5' untranslated region (5'UTR) of sarS mRNA and that a putative 18-nucleotide region played a significant role in the regulatory process. Furthermore, the mRNA half-life analysis of sarS in the gdpS mutant showed that gdpS positively regulates the mRNA levels of sarS by contributing to the stabilization of sarS mRNA, suggesting that gdpS mRNA may regulate spa expression in an RNA-dependent pathway.
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20
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Cui B, Smooker PM, Rouch DA, Deighton MA. Effects of erythromycin on the phenotypic and genotypic biofilm expression in two clinical Staphylococcus capitis subspecies and a functional analysis of Ica proteins in S. capitis. J Med Microbiol 2015; 64:591-604. [DOI: 10.1099/jmm.0.000059] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Bintao Cui
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora, 3083 Victoria, Australia
| | - Peter M. Smooker
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora, 3083 Victoria, Australia
| | - Duncan A. Rouch
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora, 3083 Victoria, Australia
| | - Margaret A. Deighton
- School of Applied Sciences, RMIT University, Plenty Road, Bundoora, 3083 Victoria, Australia
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21
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Sassi M, Augagneur Y, Mauro T, Ivain L, Chabelskaya S, Hallier M, Sallou O, Felden B. SRD: a Staphylococcus regulatory RNA database. RNA (NEW YORK, N.Y.) 2015; 21:1005-17. [PMID: 25805861 PMCID: PMC4408781 DOI: 10.1261/rna.049346.114] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 02/16/2015] [Indexed: 05/06/2023]
Abstract
An overflow of regulatory RNAs (sRNAs) was identified in a wide range of bacteria. We designed and implemented a new resource for the hundreds of sRNAs identified in Staphylococci, with primary focus on the human pathogen Staphylococcus aureus. The "Staphylococcal Regulatory RNA Database" (SRD, http://srd.genouest.org/) compiled all published data in a single interface including genetic locations, sequences and other features. SRD proposes novel and simplified identifiers for Staphylococcal regulatory RNAs (srn) based on the sRNA's genetic location in S. aureus strain N315 which served as a reference. From a set of 894 sequences and after an in-depth cleaning, SRD provides a list of 575 srn exempt of redundant sequences. For each sRNA, their experimental support(s) is provided, allowing the user to individually assess their validity and significance. RNA-seq analysis performed on strains N315, NCTC8325, and Newman allowed us to provide further details, upgrade the initial annotation, and identified 159 RNA-seq independent transcribed sRNAs. The lists of 575 and 159 sRNAs sequences were used to predict the number and location of srns in 18 S. aureus strains and 10 other Staphylococci. A comparison of the srn contents within 32 Staphylococcal genomes revealed a poor conservation between species. In addition, sRNA structure predictions obtained with MFold are accessible. A BLAST server and the intaRNA program, which is dedicated to target prediction, were implemented. SRD is the first sRNA database centered on a genus; it is a user-friendly and scalable device with the possibility to submit new sequences that should spread in the literature.
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Affiliation(s)
- Mohamed Sassi
- Inserm U835 Biochimie Pharmaceutique, Rennes University, 35043 Rennes, France
| | - Yoann Augagneur
- Inserm U835 Biochimie Pharmaceutique, Rennes University, 35043 Rennes, France
| | - Tony Mauro
- Inserm U835 Biochimie Pharmaceutique, Rennes University, 35043 Rennes, France
| | - Lorraine Ivain
- Inserm U835 Biochimie Pharmaceutique, Rennes University, 35043 Rennes, France
| | | | - Marc Hallier
- Inserm U835 Biochimie Pharmaceutique, Rennes University, 35043 Rennes, France
| | - Olivier Sallou
- Institut de Recherche en Informatique et Systèmes Aléatoires, Rennes University, 35043 Rennes, France
| | - Brice Felden
- Inserm U835 Biochimie Pharmaceutique, Rennes University, 35043 Rennes, France
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22
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Sesto N, Koutero M, Cossart P. Bacterial and cellular RNAs at work during Listeria infection. Future Microbiol 2014; 9:1025-37. [DOI: 10.2217/fmb.14.79] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
ABSTRACT Listeria monocytogenes is an intracellular pathogen that can enter and invade host cells. In the course of its infection, RNA-mediated regulatory mechanisms provide a fast and versatile response for both the bacterium and the host. They regulate a variety of processes, such as environment sensing and virulence in pathogenic bacteria, as well as development, cellular differentiation, metabolism and immune responses in eukaryotic cells. The aim of this article is to summarize first the RNA-mediated regulatory mechanisms that play a role in the Listeria lifestyle and in its virulence, and then the host miRNA responses to Listeria infection. Finally, we discuss the potential cross-talk between bacterial RNAs and host RNA regulatory mechanisms as new mechanisms of bacterial virulence.
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Affiliation(s)
- Nina Sesto
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, F-75015 Paris, France
- INSERM, U604, F-75015 Paris, France
- INRA, USC2020, F-75015 Paris, France
| | - Mikael Koutero
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, F-75015 Paris, France
- INSERM, U604, F-75015 Paris, France
- INRA, USC2020, F-75015 Paris, France
| | - Pascale Cossart
- Institut Pasteur, Unité des Interactions Bactéries-Cellules, Département de Biologie Cellulaire et Infection, F-75015 Paris, France
- INSERM, U604, F-75015 Paris, France
- INRA, USC2020, F-75015 Paris, France
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23
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The importance of regulatory RNAs in Staphylococcus aureus. INFECTION GENETICS AND EVOLUTION 2014; 21:616-26. [DOI: 10.1016/j.meegid.2013.11.016] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 11/12/2013] [Accepted: 11/13/2013] [Indexed: 12/14/2022]
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24
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Abstract
Staphylococcus aureus is a leading pathogen for animals and humans, not only being one of the most frequently isolated bacteria in hospital-associated infections but also causing diseases in the community. To coordinate the expression of its numerous virulence genes for growth and survival, S. aureus uses various signalling pathways that include two-component regulatory systems, transcription factors, and also around 250 regulatory RNAs. Biological roles have only been determined for a handful of these sRNAs, including cis, trans, and cis-trans acting RNAs, some internally encoding small, functional peptides and others possessing dual or multiple functions. Here we put forward an inventory of these fascinating sRNAs; the proteins involved in their activities; and those involved in stress response, metabolisms, and virulence.
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Affiliation(s)
- Julien Guillet
- Rennes University, Inserm U835-UpresEA2311, Pharmaceutical Biochemistry, Rennes, France
| | - Marc Hallier
- Rennes University, Inserm U835-UpresEA2311, Pharmaceutical Biochemistry, Rennes, France
| | - Brice Felden
- Rennes University, Inserm U835-UpresEA2311, Pharmaceutical Biochemistry, Rennes, France
- * E-mail:
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25
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Diep BA, Phung Q, Date S, Arnott D, Bakalarski C, Xu M, Nakamura G, Swem DL, Alexander MK, Le HN, Mai TT, Tan MW, Brown EJ, Nishiyama M. Identifying potential therapeutic targets of methicillin-resistant Staphylococcus aureus through in vivo proteomic analysis. J Infect Dis 2013; 209:1533-41. [PMID: 24280367 DOI: 10.1093/infdis/jit662] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Detailed knowledge on protein repertoire of a pathogen during host infection is needed for both developing a better understanding of the pathogenesis and defining potential therapeutic targets. Such data, however, have been missing for Staphylococcus aureus, a major human pathogen. METHODS We determined the surface proteome of methicillin-resistant S. aureus (MRSA) clone usa300 derived directly from murine systemic infectiON. RESULTS The majority of the in vivo-expressed surface-associated proteins were lipoproteins involved in nutrient acquisition, especially uptake of metal ions. Enzyme-linked immunosorbent assay (ELISA) of convalescent human serum samples revealed that proteins that were highly produced during murine experimental infection were also produced during natural human infection. We found that among the 7 highly abundant lipoproteins only MntC, which is the manganese-binding protein of the MntABC system, was essential for MRSA virulence during murine systemic infection. Moreover, we show that MntA and MntB are equally important for MRSA virulence. CONCLUSIONS Besides providing experimental evidence that MntABC might be a potential therapeutic target for the development of antibiotics, our in vivo proteomics data will serve as a valuable basis for defining potential antigen combinations for multicomponent vaccines.
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Affiliation(s)
- Binh An Diep
- Department of Medicine, University of California, San Francisco
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26
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Luna B, Galán-Vásquez E, Ugalde E, Martínez-Antonio A. Structural comparison of biological networks based on dominant vertices. MOLECULAR BIOSYSTEMS 2013; 9:1765-73. [DOI: 10.1039/c3mb70077a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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27
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Brantl S. Acting antisense: plasmid- and chromosome-encoded sRNAs from Gram-positive bacteria. Future Microbiol 2012; 7:853-71. [DOI: 10.2217/fmb.12.59] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
sRNAs that act by base pairing were first discovered in plasmids, phages and transposons, where they control replication, maintenance and transposition. Since 2001, however, computational searches were applied that led to the discovery of a plethora of sRNAs in bacterial chromosomes. Whereas the majority of these chromsome-encoded sRNAs have been investigated in Escherichia coli, Salmonella and other Gram-negative bacteria, only a few well-studied examples are known from Gram-positive bacteria. Here, the author summarizes our current knowledge on plasmid- and chromosome-encoded sRNAs from Gram-positive species, thereby focusing on regulatory mechanisms used by these RNAs and their biological role in complex networks. Furthermore, regulatory factors that control the expression of these RNAs will be discussed and differences between sRNAs from Gram-positive and Gram-negative bacteria highlighted. The main emphasis of this review is on sRNAs that act by base pairing (i.e., by an antisense mechanism). Thereby, both plasmid-encoded and chromosome-encoded sRNAs will be considered.
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Affiliation(s)
- Sabine Brantl
- AG Bakteriengenetik, Friedrich-Schiller-Universität Jena, Philosophenweg 12, D-07743 Jena, Germany
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28
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Romilly C, Caldelari I, Parmentier D, Lioliou E, Romby P, Fechter P. Current knowledge on regulatory RNAs and their machineries in Staphylococcus aureus. RNA Biol 2012; 9:402-13. [PMID: 22546940 DOI: 10.4161/rna.20103] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Staphylococcus aureus is one of the major human pathogens, which causes numerous community-associated and hospital-acquired infections. The regulation of the expression of numerous virulence factors is coordinated by complex interplays between two component systems, transcriptional regulatory proteins, and regulatory RNAs. Recent studies have identified numerous novel RNAs comprising cis-acting regulatory RNAs, antisense RNAs, small non coding RNAs and small mRNAs encoding peptides. We present here several examples of RNAs regulating S. aureus pathogenicity and describe various aspects of antisense regulation.
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Affiliation(s)
- Cédric Romilly
- Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
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29
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Cue D, Lei MG, Lee CY. Genetic regulation of the intercellular adhesion locus in staphylococci. Front Cell Infect Microbiol 2012; 2:38. [PMID: 23061050 PMCID: PMC3459252 DOI: 10.3389/fcimb.2012.00038] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 03/05/2012] [Indexed: 01/29/2023] Open
Abstract
The formation of biofilms by Staphylococcus aureus and Staphylococcus epidermidis is an important aspect of many staphylococcal infections, most notably endocarditis, osteomyelitis and infections associated with indwelling medical devices. The major constituents of staphylococcal biofilms are polysaccharides, such as poly N-acetyl glucosamine (PIA/PNAG), cell surface and secreted bacterial proteins, and extracellular DNA. The exact composition of biofilms often varies considerably between different strains of staphylococci and between different sites of infection by the same strain. PIA/PNAG is synthesized by the products of four genes, icaADBC, that are encoded in a single operon. A fifth gene, icaR, is a negative regulator of icaADBC. Expression of icaADBC is tightly regulated, but can often be induced in vitro by growing staphylococci in the presence of high salt, high glucose, or ethanol. Regulation of icaADBC is complex and numerous regulatory factors have been implicated in control of icaADBC. Many of these are well known global transcriptional regulatory factors like SarA and sigmaB, whereas other regulators, such as IcaR, seem to affect expression of relatively few genes. Here, we will summarize how various regulatory factors affect the production of PIA/PNAG in staphylococci.
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Affiliation(s)
- David Cue
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock AR, USA
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30
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Chen HY, Chen CC, Fang CS, Hsieh YT, Lin MH, Shu JC. Vancomycin activates σ(B) in vancomycin-resistant Staphylococcus aureus resulting in the enhancement of cytotoxicity. PLoS One 2011; 6:e24472. [PMID: 21912698 PMCID: PMC3166330 DOI: 10.1371/journal.pone.0024472] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2011] [Accepted: 08/11/2011] [Indexed: 12/16/2022] Open
Abstract
The alternative transcription factor σB is responsible for transcription in Staphylococcus aureus during the stress response. Many virulence-associated genes are directly or indirectly regulated by σB. We hypothesized that treatment with antibiotics may act as an environmental stressor that induces σB activity in antibiotic-resistant strains. Several antibiotics with distinct modes of action, including ampicillin (12 µg/ml), vancomycin (16 or 32 µg/ml), chloramphenicol (15 µg/ml), ciprofloxacin (0.25 µg/ml), and sulfamethoxazole/trimethoprim (SXT, 0.8 µg/ml), were investigated for their ability to activate this transcription factor. We were especially interested in the stress response in vancomycin-resistant S. aureus (VRSA) strains treated with vancomycin. The transcription levels of selected genes associated with virulence were also measured. Real-time quantitative reverse transcription PCR was employed to evaluate gene transcription levels. Contact hemolytic and cytotoxicity assays were used to evaluate cell damage following antibiotic treatment. Antibiotics that target the cell wall (vancomycin and ampicillin) and SXT induced σB activity in VRSA strains. Expression of σB-regulated virulence genes, including hla and fnbA, was associated with the vancomycin-induced σB activity in VRSA strains and the increase in cytotoxicity upon vancomycin treatment. These effects were not observed in the sigB-deficient strain but were observed in the complemented strain. We demonstrate that sub-minimum inhibitory concentration (sub-MIC) levels of antibiotics act as environmental stressors and activate the stress response sigma factor, σB. The improper use of antibiotics may alter the expression of virulence factors through the activation of σB in drug-resistant strains of S. aureus and lead to worse clinical outcomes.
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Affiliation(s)
- Hong-Yi Chen
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
| | - Chien-Cheng Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Chun-Sheng Fang
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Ting Hsieh
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
| | - Mei-Hui Lin
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
- Research Center for Pathogenic Bacteria, Chang Gung University, Taoyuan, Taiwan
| | - Jwu-Ching Shu
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan, Taiwan
- Research Center for Pathogenic Bacteria, Chang Gung University, Taoyuan, Taiwan
- * E-mail:
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31
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Abstract
Staphylococcus aureus is a major human pathogen causing a wide spectrum of nosocomial and community-associated infections with high morbidity and mortality. S. aureus generates a large number of virulence factors whose timing and expression levels are precisely tuned by regulatory proteins and RNAs. The aptitude of bacteria to use RNAs to rapidly modify gene expression, including virulence factors in response to stress or environmental changes, and to survive in a host is an evolving concept. Here, we focus on the recently inventoried S. aureus regulatory RNAs, with emphasis on those with identified functions, two of which are directly involved in pathogenicity.
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