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Hegelmeyer NK, Parkin LA, Previti ML, Andrade J, Utama R, Sejour RJ, Gardin J, Muller S, Ketchum S, Yurovsky A, Futcher B, Goodwin S, Ueberheide B, Seeliger JC. Gene recoding by synonymous mutations creates promiscuous intragenic transcription initiation in mycobacteria. mBio 2023; 14:e0084123. [PMID: 37787543 PMCID: PMC10653884 DOI: 10.1128/mbio.00841-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/16/2023] [Indexed: 10/04/2023] Open
Abstract
IMPORTANCE Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, one of the deadliest infectious diseases worldwide. Previous studies have established that synonymous recoding to introduce rare codon pairings can attenuate viral pathogens. We hypothesized that non-optimal codon pairing could be an effective strategy for attenuating gene expression to create a live vaccine for Mtb. We instead discovered that these synonymous changes enabled the transcription of functional mRNA that initiated in the middle of the open reading frame and from which many smaller protein products were expressed. To our knowledge, this is one of the first reports that synonymous recoding of a gene in any organism can create or induce intragenic transcription start sites.
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Affiliation(s)
- Nuri K. Hegelmeyer
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Lia A. Parkin
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Mary L. Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
| | - Raditya Utama
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Richard J. Sejour
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Justin Gardin
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Stephanie Muller
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Steven Ketchum
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Alisa Yurovsky
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Bruce Futcher
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Sara Goodwin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
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2
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Hegelmeyer NK, Previti ML, Andrade J, Utama R, Sejour RJ, Gardin J, Muller S, Ketchum S, Yurovsky A, Futcher B, Goodwin S, Ueberheide B, Seeliger JC. Gene recoding by synonymous mutations creates promiscuous intragenic transcription initiation in mycobacteria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.17.532606. [PMID: 36993691 PMCID: PMC10055193 DOI: 10.1101/2023.03.17.532606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Each genome encodes some codons more frequently than their synonyms (codon usage bias), but codons are also arranged more frequently into specific pairs (codon pair bias). Recoding viral genomes and yeast or bacterial genes with non-optimal codon pairs has been shown to decrease gene expression. Gene expression is thus importantly regulated not only by the use of particular codons but by their proper juxtaposition. We therefore hypothesized that non-optimal codon pairing could likewise attenuate Mtb genes. We explored the role of codon pair bias by recoding Mtb genes ( rpoB, mmpL3, ndh ) and assessing their expression in the closely related and tractable model organism M. smegmatis . To our surprise, recoding caused the expression of multiple smaller protein isoforms from all three genes. We confirmed that these smaller proteins were not due to protein degradation, but instead issued from new transcription initiation sites positioned within the open reading frame. New transcripts gave rise to intragenic translation initiation sites, which in turn led to the expression of smaller proteins. We next identified the nucleotide changes associated with these new sites of transcription and translation. Our results demonstrated that apparently benign, synonymous changes can drastically alter gene expression in mycobacteria. More generally, our work expands our understanding of the codon-level parameters that control translation and transcription initiation. IMPORTANCE Mycobacterium tuberculosis ( Mtb ) is the causative agent of tuberculosis, one of the deadliest infectious diseases worldwide. Previous studies have established that synonymous recoding to introduce rare codon pairings can attenuate viral pathogens. We hypothesized that non-optimal codon pairing could be an effective strategy for attenuating gene expression to create a live vaccine for Mtb . We instead discovered that these synonymous changes enabled the transcription of functional mRNA that initiated in the middle of the open reading frame and from which many smaller protein products were expressed. To our knowledge, this is the first report that synonymous recoding of a gene in any organism can create or induce intragenic transcription start sites.
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Affiliation(s)
- Nuri K. Hegelmeyer
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Mary L. Previti
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Joshua Andrade
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
| | - Raditya Utama
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Richard J. Sejour
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Justin Gardin
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Stephanie Muller
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Steven Ketchum
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Alisa Yurovsky
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Bruce Futcher
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Sara Goodwin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, New York University Grossman School of Medicine, New York, New York, USA
- Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, New York, USA
| | - Jessica C. Seeliger
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, New York, USA
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Adaptation of the gut pathobiont Enterococcus faecalis to deoxycholate and taurocholate bile acids. Sci Rep 2022; 12:8485. [PMID: 35590028 PMCID: PMC9120511 DOI: 10.1038/s41598-022-12552-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 05/11/2022] [Indexed: 11/24/2022] Open
Abstract
Enterococcus faecalis is a natural inhabitant of the human gastrointestinal tract. This bacterial species is subdominant in a healthy physiological state of the gut microbiota (eubiosis) in adults, but can become dominant and cause infections when the intestinal homeostasis is disrupted (dysbiosis). The relatively high concentrations of bile acids deoxycholate (DCA) and taurocholate (TCA) hallmark eubiosis and dysbiosis, respectively. This study aimed to better understand how E. faecalis adapts to DCA and TCA. We showed that DCA impairs E. faecalis growth and possibly imposes a continuous adjustment in the expression of many essential genes, including a majority of ribosomal proteins. This may account for slow growth and low levels of E. faecalis in the gut. In contrast, TCA had no detectable growth effect. The evolving transcriptome upon TCA adaptation showed the early activation of an oligopeptide permease system (opp2) followed by the adjustment of amino acid and nucleotide metabolisms. We provide evidence that TCA favors the exploitation of oligopeptide resources to fuel amino acid needs in limiting oligopeptide conditions. Altogether, our data suggest that the combined effects of decreased DCA and increased TCA concentrations can contribute to the rise of E. faecalis population during dysbiosis.
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Johnson CN, Sheriff EK, Duerkop BA, Chatterjee A. Let Me Upgrade You: Impact of Mobile Genetic Elements on Enterococcal Adaptation and Evolution. J Bacteriol 2021; 203:e0017721. [PMID: 34370561 PMCID: PMC8508098 DOI: 10.1128/jb.00177-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococci are Gram-positive bacteria that have evolved to thrive as both commensals and pathogens, largely due to their accumulation of mobile genetic elements via horizontal gene transfer (HGT). Common agents of HGT include plasmids, transposable elements, and temperate bacteriophages. These vehicles of HGT have facilitated the evolution of the enterococci, specifically Enterococcus faecalis and Enterococcus faecium, into multidrug-resistant hospital-acquired pathogens. On the other hand, commensal strains of Enterococcus harbor CRISPR-Cas systems that prevent the acquisition of foreign DNA, restricting the accumulation of mobile genetic elements. In this review, we discuss enterococcal mobile genetic elements by highlighting their contributions to bacterial fitness, examine the impact of CRISPR-Cas on their acquisition, and identify key areas of research that can improve our understanding of enterococcal evolution and ecology.
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Affiliation(s)
- Cydney N. Johnson
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Emma K. Sheriff
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Breck A. Duerkop
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Anushila Chatterjee
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, Colorado, USA
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5
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Cataldo PG, Klemm P, Thüring M, Saavedra L, Hebert EM, Hartmann RK, Lechner M. Insights into 6S RNA in lactic acid bacteria (LAB). BMC Genom Data 2021; 22:29. [PMID: 34479493 PMCID: PMC8414754 DOI: 10.1186/s12863-021-00983-2] [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: 06/21/2021] [Accepted: 08/12/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND 6S RNA is a regulator of cellular transcription that tunes the metabolism of cells. This small non-coding RNA is found in nearly all bacteria and among the most abundant transcripts. Lactic acid bacteria (LAB) constitute a group of microorganisms with strong biotechnological relevance, often exploited as starter cultures for industrial products through fermentation. Some strains are used as probiotics while others represent potential pathogens. Occasional reports of 6S RNA within this group already indicate striking metabolic implications. A conceivable idea is that LAB with 6S RNA defects may metabolize nutrients faster, as inferred from studies of Echerichia coli. This may accelerate fermentation processes with the potential to reduce production costs. Similarly, elevated levels of secondary metabolites might be produced. Evidence for this possibility comes from preliminary findings regarding the production of surfactin in Bacillus subtilis, which has functions similar to those of bacteriocins. The prerequisite for its potential biotechnological utility is a general characterization of 6S RNA in LAB. RESULTS We provide a genomic annotation of 6S RNA throughout the Lactobacillales order. It laid the foundation for a bioinformatic characterization of common 6S RNA features. This covers secondary structures, synteny, phylogeny, and product RNA start sites. The canonical 6S RNA structure is formed by a central bulge flanked by helical arms and a template site for product RNA synthesis. 6S RNA exhibits strong syntenic conservation. It is usually flanked by the replication-associated recombination protein A and the universal stress protein A. A catabolite responsive element was identified in over a third of all 6S RNA genes. It is known to modulate gene expression based on the available carbon sources. The presence of antisense transcripts could not be verified as a general trait of LAB 6S RNAs. CONCLUSIONS Despite a large number of species and the heterogeneity of LAB, the stress regulator 6S RNA is well-conserved both from a structural as well as a syntenic perspective. This is the first approach to describe 6S RNAs and short 6S RNA-derived transcripts beyond a single species, spanning a large taxonomic group covering multiple families. It yields universal insights into this regulator and complements the findings derived from other bacterial model organisms.
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Affiliation(s)
- Pablo Gabriel Cataldo
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Paul Klemm
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Marietta Thüring
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Lucila Saavedra
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Elvira Maria Hebert
- Centro de Referencia para Lactobacilos (CERELA-CONICET), Chacabuco 145, San Miguel de Tucumán, 4000, Argentina
| | - Roland K Hartmann
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany
| | - Marcus Lechner
- Philipps-Universität Marburg, Institut für Pharmazeutische Chemie, Marbacher Weg 6, Marburg, 35032, Germany. .,Philipps-Universität Marburg, Center for Synthetic Microbiology (Synmikro), Hans-Meerwein-Straße 6, Marburg, 35043, Germany.
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Zhang Y, Sun L, Zhu R, Zhang S, Liu S, Wang Y, Wu Y, Liao X, Mi J. Absence of Circadian Rhythm in Fecal Microbiota of Laying Hens under Common Light. Animals (Basel) 2021; 11:2065. [PMID: 34359193 PMCID: PMC8300245 DOI: 10.3390/ani11072065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/05/2021] [Accepted: 07/07/2021] [Indexed: 12/28/2022] Open
Abstract
The circadian rhythm of gut microbiota is an important biological rhythm that plays a crucial role in host health. However, few studies have determined the associations between the circadian rhythm and gut microbiota in laying hens. The present experiment investigated the circadian rhythm of fecal microbiota in laying hens. Feces samples were collected from 10 laying hens at nine different time points (06:00-12:00-18:00-00:00-06:00-12:00-18:00-00:00-06:00) to demonstrate the circadian rhythm of fecal microbiota. The results showed that the α and β diversity of the fecal microbiota fluctuated significantly at different time points. Beta nearest taxon index analysis suggested that assembly strategies of the abundant and rare amplicon sequence variant (ASV) sub-communities were different. Abundant ASVs preferred dispersal limitation (weak selection), and rare ASVs were randomly formed due to the "non-dominant" fractions. Highly robust fluctuations of fecal microbiota at the phylum level were found. For example, Firmicutes and Proteobacteria fluctuated inversely to each other, but the total ratio remained in a dynamic balance over 48 h. We identified that temporal dynamic changes had a significant effect on the relative abundance of the important bacteria in the feces microbial community using the random forest algorithm. Eight bacteria, Ruminococcus gnavus, Faecalibacterium, Ruminococcaceae, Enterococcus cecorum, Lachnospiraceae, Clostridium, Clostridiales, and Megamonas, showed significant changes over time. One unexpected finding was the fact that these eight bacteria belong to Firmicutes. The pathways showed significant fluctuation, including xenobiotic biodegradation and metabolism, carbohydrate metabolism, and amino acid metabolism, which were consistent with the metabolic functions of amino acids and carbohydrates from the feed. This study showed that the defecation time may be an important factor in the diversity, proportion, and functions of the feces microbial community. However, there was no circadian rhythm of microbial community assembly confirmed by JTK_Cycle analysis. These results might suggest there was no obvious circadian rhythm of fecal microbiota in laying hens under common light.
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Affiliation(s)
- Yu Zhang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Lan Sun
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Run Zhu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Shiyu Zhang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Shuo Liu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Yan Wang
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Yinbao Wu
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Xindi Liao
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
| | - Jiandui Mi
- National Engineering Research Center for Breeding Swine Industry, College of Animal Science, South China Agriculture University, Guangzhou 510642, China; (Y.Z.); (L.S.); (R.Z.); (S.Z.); (S.L.); (Y.W.); (Y.W.)
- Ministry of Agriculture Key Laboratory of Tropical Agricultural Environment, South China Agricultural University, Guangzhou 510642, China
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, Guangzhou 510642, China
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Porrini C, Guérin C, Tran SL, Dervyn R, Nicolas P, Ramarao N. Implication of a Key Region of Six Bacillus cereus Genes Involved in Siroheme Synthesis, Nitrite Reductase Production and Iron Cluster Repair in the Bacterial Response to Nitric Oxide Stress. Int J Mol Sci 2021; 22:ijms22105079. [PMID: 34064887 PMCID: PMC8151001 DOI: 10.3390/ijms22105079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/01/2021] [Accepted: 05/04/2021] [Indexed: 12/30/2022] Open
Abstract
Bacterial response to nitric oxide (NO) is of major importance for bacterial survival. NO stress is a main actor of the eukaryotic immune response and several pathogenic bacteria have developed means for detoxification and repair of the damages caused by NO. However, bacterial mechanisms of NO resistance by Gram-positive bacteria are poorly described. In the opportunistic foodborne pathogen Bacillus cereus, genome sequence analyses did not identify homologs to known NO reductases and transcriptional regulators, such as NsrR, which orchestrate the response to NO of other pathogenic or non-pathogenic bacteria. Using a transcriptomic approach, we investigated the adaptation of B. cereus to NO stress. A cluster of 6 genes was identified to be strongly up-regulated in the early phase of the response. This cluster contains an iron-sulfur cluster repair enzyme, a nitrite reductase and three enzymes involved in siroheme biosynthesis. The expression pattern and close genetic localization suggest a functional link between these genes, which may play a pivotal role in the resistance of B. cereus to NO stress during infection.
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Affiliation(s)
- Constance Porrini
- Micalis Institute, AgroParisTech, INRAE, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (C.P.); (S.-L.T.); (R.D.)
| | - Cyprien Guérin
- MaIAGE, INRAE, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (C.G.); (P.N.)
| | - Seav-Ly Tran
- Micalis Institute, AgroParisTech, INRAE, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (C.P.); (S.-L.T.); (R.D.)
| | - Rozenn Dervyn
- Micalis Institute, AgroParisTech, INRAE, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (C.P.); (S.-L.T.); (R.D.)
| | - Pierre Nicolas
- MaIAGE, INRAE, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (C.G.); (P.N.)
| | - Nalini Ramarao
- Micalis Institute, AgroParisTech, INRAE, Université Paris-Saclay, 78350 Jouy-en-Josas, France; (C.P.); (S.-L.T.); (R.D.)
- Correspondence:
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8
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Michaux C, Hansen EE, Jenniches L, Gerovac M, Barquist L, Vogel J. Single-Nucleotide RNA Maps for the Two Major Nosocomial Pathogens Enterococcus faecalis and Enterococcus faecium. Front Cell Infect Microbiol 2020; 10:600325. [PMID: 33324581 PMCID: PMC7724050 DOI: 10.3389/fcimb.2020.600325] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 10/19/2020] [Indexed: 12/19/2022] Open
Abstract
Enterococcus faecalis and faecium are two major representative clinical strains of the Enterococcus genus and are sadly notorious to be part of the top agents responsible for nosocomial infections. Despite their critical implication in worldwide public healthcare, essential and available resources such as deep transcriptome annotations remain poor, which also limits our understanding of post-transcriptional control small regulatory RNA (sRNA) functions in these bacteria. Here, using the dRNA-seq technique in combination with ANNOgesic analysis, we successfully mapped and annotated transcription start sites (TSS) of both E. faecalis V583 and E. faecium AUS0004 at single nucleotide resolution. Analyzing bacteria in late exponential phase, we capture ~40% (E. faecalis) and 43% (E. faecium) of the annotated protein-coding genes, determine 5′ and 3′ UTR (untranslated region) length, and detect instances of leaderless mRNAs. The transcriptome maps revealed sRNA candidates in both bacteria, some found in previous studies and new ones. Expression of candidate sRNAs is being confirmed under biologically relevant environmental conditions. This comprehensive global TSS mapping atlas provides a valuable resource for RNA biology and gene expression analysis in the Enterococci. It can be accessed online at www.helmholtz-hiri.de/en/datasets/enterococcus through an instance of the genomic viewer JBrowse.
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Affiliation(s)
- Charlotte Michaux
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Elisabeth E Hansen
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Laura Jenniches
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), Würzburg, Germany
| | - Milan Gerovac
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), Würzburg, Germany.,Faculty of Medicine, University of Würzburg, Würzburg, Germany
| | - Jörg Vogel
- Institute for Molecular Infection Biology, University of Würzburg, Würzburg, Germany.,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), Würzburg, Germany
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9
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Cross-Regulations between Bacterial Toxin-Antitoxin Systems: Evidence of an Interconnected Regulatory Network? Trends Microbiol 2020; 28:851-866. [PMID: 32540313 DOI: 10.1016/j.tim.2020.05.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 12/31/2022]
Abstract
Toxin-antitoxin (TA) systems are ubiquitous among bacteria and include stable toxins whose toxicity can be counteracted by RNA or protein antitoxins. They are involved in multiple functions that range from stability maintenance for mobile genetic elements to stress adaptation. Bacterial chromosomes frequently have multiple homologues of TA system loci, and it is unclear why there are so many of them. In this review we focus on cross-regulations between TA systems, which occur between both homologous and nonhomologous systems, from similar or distinct types, whether encoded from plasmids or chromosomes. In addition to being able to modulate RNA expression levels, cross-regulations between these systems can also influence their toxicity. This suggests the idea that they are involved in an interconnected regulatory network.
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10
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Lacoux C, Fouquier d'Hérouël A, Wessner-Le Bohec F, Innocenti N, Bohn C, Kennedy SP, Rochat T, Bonnin RA, Serror P, Aurell E, Bouloc P, Repoila F. Dynamic insights on transcription initiation and RNA processing during bacterial adaptation. RNA (NEW YORK, N.Y.) 2020; 26:382-395. [PMID: 31992590 PMCID: PMC7075262 DOI: 10.1261/rna.073288.119] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/20/2020] [Indexed: 05/04/2023]
Abstract
Transcription initiation and RNA processing govern gene expression and enable bacterial adaptation by reshaping the RNA landscape. The aim of this study was to simultaneously observe these two fundamental processes in a transcriptome responding to an environmental signal. A controlled σE system in E. coli was coupled to our previously described tagRNA-seq method to yield process kinetics information. Changes in transcription initiation frequencies (TIF) and RNA processing frequencies (PF) were followed using 5' RNA tags. Changes in TIF showed a binary increased/decreased pattern that alternated between transcriptionally activated and repressed promoters, providing the bacterial population with transcriptional oscillation. PF variation fell into three categories of cleavage activity: (i) constant and independent of RNA levels, (ii) increased once RNA has accumulated, and (iii) positively correlated to changes in TIF. This work provides a comprehensive and dynamic view of major events leading to transcriptomic reshaping during bacterial adaptation. It unveils an interplay between transcription initiation and the activity of specific RNA cleavage sites. This study utilized a well-known genetic system to analyze fundamental processes and can serve as a blueprint for comprehensive studies that exploit the RNA metabolism to decipher and understand bacterial gene expression control.
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Affiliation(s)
- Caroline Lacoux
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
| | | | | | - Nicolas Innocenti
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
- Department of Computational Biology, Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Chantal Bohn
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Sean P Kennedy
- Department of Computational Biology, USR3756 CNRS, Institut Pasteur, 75 015 Paris, France
| | - Tatiana Rochat
- VIM, INRA, Université Paris-Saclay, 78350 Jouy-en-Josas, France
| | - Rémy A Bonnin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Pascale Serror
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
| | - Erik Aurell
- Department of Computational Biology, Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden
| | - Philippe Bouloc
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Francis Repoila
- Université Paris-Saclay, INRAE, AgroParisTech, MIcalis Institute, 78350, Jouy-en-Josas, France
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11
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de Souza Pinto Lemgruber R, Valgepea K, Gonzalez Garcia RA, de Bakker C, Palfreyman RW, Tappel R, Köpke M, Simpson SD, Nielsen LK, Marcellin E. A TetR-Family Protein (CAETHG_0459) Activates Transcription From a New Promoter Motif Associated With Essential Genes for Autotrophic Growth in Acetogens. Front Microbiol 2019; 10:2549. [PMID: 31803150 PMCID: PMC6873888 DOI: 10.3389/fmicb.2019.02549] [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: 10/12/2018] [Accepted: 10/22/2019] [Indexed: 01/08/2023] Open
Abstract
Acetogens can fix carbon (CO or CO2) into acetyl-CoA via the Wood-Ljungdahl pathway (WLP) that also makes them attractive cell factories for the production of fuels and chemicals from waste feedstocks. Although most biochemical details of the WLP are well understood and systems-level characterization of acetogen metabolism has recently improved, key transcriptional features such as promoter motifs and transcriptional regulators are still unknown in acetogens. Here, we use differential RNA-sequencing to identify a previously undescribed promoter motif associated with essential genes for autotrophic growth of the model-acetogen Clostridium autoethanogenum. RNA polymerase was shown to bind to the new promoter motif using a DNA-binding protein assay and proteomics enabled the discovery of four candidates to potentially function directly in control of transcription of the WLP and other key genes of C1 fixation metabolism. Next, in vivo experiments showed that a TetR-family transcriptional regulator (CAETHG_0459) and the housekeeping sigma factor (σA) activate expression of a reporter protein (GFP) in-frame with the new promoter motif from a fusion vector in Escherichia coli. Lastly, a protein-protein interaction assay with the RNA polymerase (RNAP) shows that CAETHG_0459 directly binds to the RNAP. Together, the data presented here advance the fundamental understanding of transcriptional regulation of C1 fixation in acetogens and provide a strategy for improving the performance of gas-fermenting bacteria by genetic engineering.
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Affiliation(s)
| | - Kaspar Valgepea
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, Australia
- ERA Chair in Gas Fermentation Technologies, Institute of Technology, University of Tartu, Tartu, Estonia
| | | | - Christopher de Bakker
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, Australia
| | - Robin William Palfreyman
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, Australia
- Queensland Node of Metabolomics Australia, The University of Queensland, Brisbane, QLD, Australia
| | | | | | | | - Lars Keld Nielsen
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, Australia
| | - Esteban Marcellin
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD, Australia
- Queensland Node of Metabolomics Australia, The University of Queensland, Brisbane, QLD, Australia
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12
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Salze M, Giard JC, Riboulet-Bisson E, Hain T, Rincé A, Muller C. Identification of the general stress stimulon related to colonization in Enterococcus faecalis. Arch Microbiol 2019; 202:233-246. [DOI: 10.1007/s00203-019-01735-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 09/06/2019] [Accepted: 09/21/2019] [Indexed: 01/08/2023]
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13
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Lejars M, Kobayashi A, Hajnsdorf E. Physiological roles of antisense RNAs in prokaryotes. Biochimie 2019; 164:3-16. [PMID: 30995539 DOI: 10.1016/j.biochi.2019.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/12/2019] [Indexed: 12/16/2022]
Abstract
Prokaryotes encounter constant and often brutal modifications to their environment. In order to survive, they need to maintain fitness, which includes adapting their protein expression patterns. Many factors control gene expression but this review focuses on just one, namely antisense RNAs (asRNAs), a class of non-coding RNAs (ncRNAs) characterized by their location in cis and their perfect complementarity with their targets. asRNAs were considered for a long time to be trivial and only to be found on mobile genetic elements. However, recent advances in methodology have revealed that their abundance and potential activities have been underestimated. This review aims to illustrate the role of asRNA in various physiologically crucial functions in both archaea and bacteria, which can be regrouped in three categories: cell maintenance, horizontal gene transfer and virulence. A literature survey of asRNAs demonstrates the difficulties to characterize and assign a role to asRNAs. With the aim of facilitating this task, we describe recent technological advances that could be of interest to identify new asRNAs and to discover their function.
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Affiliation(s)
- Maxence Lejars
- CNRS UMR8261, IBPC, 13 rue Pierre et Marie Curie, 75005, Paris, France.
| | - Asaki Kobayashi
- SABNP, INSERM U1204, Université d'Evry Val-d'Essonne, Bâtiment Maupertuis, Rue du Père Jarlan, 91000, Évry Cedex, France.
| | - Eliane Hajnsdorf
- CNRS UMR8261, IBPC, 13 rue Pierre et Marie Curie, 75005, Paris, France.
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14
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Abstract
The study of the genetics of enterococci has focused heavily on mobile genetic elements present in these organisms, the complex regulatory circuits used to control their mobility, and the antibiotic resistance genes they frequently carry. Recently, more focus has been placed on the regulation of genes involved in the virulence of the opportunistic pathogenic species Enterococcus faecalis and Enterococcus faecium. Little information is available concerning fundamental aspects of DNA replication, partition, and division; this article begins with a brief overview of what little is known about these issues, primarily by comparison with better-studied model organisms. A variety of transcriptional and posttranscriptional mechanisms of regulation of gene expression are then discussed, including a section on the genetics and regulation of vancomycin resistance in enterococci. The article then provides extensive coverage of the pheromone-responsive conjugation plasmids, including sections on regulation of the pheromone response, the conjugative apparatus, and replication and stable inheritance. The article then focuses on conjugative transposons, now referred to as integrated, conjugative elements, or ICEs, and concludes with several smaller sections covering emerging areas of interest concerning the enterococcal mobilome, including nonpheromone plasmids of particular interest, toxin-antitoxin systems, pathogenicity islands, bacteriophages, and genome defense.
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15
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van de Groep K, Bos MP, Savelkoul PHM, Rubenjan A, Gazenbeek C, Melchers WJG, van der Poll T, Juffermans NP, Ong DSY, Bonten MJM, Cremer OL. Development and first evaluation of a novel multiplex real-time PCR on whole blood samples for rapid pathogen identification in critically ill patients with sepsis. Eur J Clin Microbiol Infect Dis 2018; 37:1333-1344. [PMID: 29700761 PMCID: PMC6015113 DOI: 10.1007/s10096-018-3255-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 04/06/2018] [Indexed: 12/19/2022]
Abstract
Molecular tests may enable early adjustment of antimicrobial therapy and be complementary to blood culture (BC) which has imperfect sensitivity in critically ill patients. We evaluated a novel multiplex real-time PCR assay to diagnose bloodstream pathogens directly in whole blood samples (BSI-PCR). BSI-PCR included 11 species- and four genus-specific PCRs, a molecular Gram-stain PCR, and two antibiotic resistance markers. We collected 5 mL blood from critically ill patients simultaneously with clinically indicated BC. Microbial DNA was isolated using the Polaris method followed by automated DNA extraction. Sensitivity and specificity were calculated using BC as reference. BSI-PCR was evaluated in 347 BC-positive samples (representing up to 50 instances of each pathogen covered by the test) and 200 BC-negative samples. Bacterial species-specific PCR sensitivities ranged from 65 to 100%. Sensitivity was 26% for the Gram-positive PCR, 32% for the Gram-negative PCR, and ranged 0 to 7% for yeast PCRs. Yeast detection was improved to 40% in a smaller set-up. There was no overall association between BSI-PCR sensitivity and time-to-positivity of BC (which was highly variable), yet Ct-values were lower for true-positive versus false-positive PCR results. False-positive results were observed in 84 (4%) of the 2200 species-specific PCRs in 200 culture-negative samples, and ranged from 0 to 6% for generic PCRs. Sensitivity of BSI-PCR was promising for individual bacterial pathogens, but still insufficient for yeasts and generic PCRs. Further development of BSI-PCR will focus on improving sensitivity by increasing input volumes and on subsequent implementation as a bedside test.
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Affiliation(s)
- Kirsten van de Groep
- Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands. .,Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht University, Room F06.149, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
| | | | - Paul H M Savelkoul
- Microbiome, Amsterdam, the Netherlands.,Department of Medical Microbiology & Infection Control, VU University Medical Center, Amsterdam, the Netherlands.,Department of Medical Microbiology, Maastricht University Medical Center, Maastricht, the Netherlands
| | | | | | - Willem J G Melchers
- Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Tom van der Poll
- Center of Experimental and Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands.,Division of Infectious Diseases, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - Nicole P Juffermans
- Department of Intensive Care, Academic Medical Center, University of Amsterdam, Amsterdam, the Netherlands
| | - David S Y Ong
- Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht University, Room F06.149, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.,Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Marc J M Bonten
- Department of Epidemiology, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands.,Department of Medical Microbiology, University Medical Center Utrecht, Utrecht University, Utrecht, the Netherlands
| | - Olaf L Cremer
- Department of Intensive Care Medicine, University Medical Center Utrecht, Utrecht University, Room F06.149, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands
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16
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Nouaille S, Mondeil S, Finoux AL, Moulis C, Girbal L, Cocaign-Bousquet M. The stability of an mRNA is influenced by its concentration: a potential physical mechanism to regulate gene expression. Nucleic Acids Res 2017; 45:11711-11724. [PMID: 28977619 PMCID: PMC5714132 DOI: 10.1093/nar/gkx781] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 08/28/2017] [Indexed: 01/19/2023] Open
Abstract
Changing mRNA stability is a major post-transcriptional way of controlling gene expression, particularly in newly encountered conditions. As the concentration of mRNA is the result of an equilibrium between transcription and degradation, it is generally assumed that at constant transcription, any change in mRNA concentration is the consequence of mRNA stabilization or destabilization. However, the literature reports many cases of opposite variations in mRNA concentration and stability in bacteria. Here, we analyzed the causal link between the concentration and stability of mRNA in two phylogenetically distant bacteria Escherichia coli and Lactococcus lactis. Using reporter mRNAs, we showed that modifying the stability of an mRNA had unpredictable effects, either higher or lower, on its concentration, whereas increasing its concentration systematically reduced stability. This inverse relationship between the concentration and stability of mRNA was generalized to native genes at the genome scale in both bacteria. Higher mRNA turnover in the case of higher concentrations appears to be a simple physical mechanism to regulate gene expression in the bacterial kingdom. The consequences for bacterial adaptation of this control of the stability of an mRNA by its concentration are discussed.
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Affiliation(s)
- Sébastien Nouaille
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. 135 av de Rangueil. 31077 Toulouse Cedex 4, France
| | - Sophie Mondeil
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. 135 av de Rangueil. 31077 Toulouse Cedex 4, France
| | - Anne-Laure Finoux
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. 135 av de Rangueil. 31077 Toulouse Cedex 4, France
| | - Claire Moulis
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. 135 av de Rangueil. 31077 Toulouse Cedex 4, France
| | - Laurence Girbal
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. 135 av de Rangueil. 31077 Toulouse Cedex 4, France
| | - Muriel Cocaign-Bousquet
- LISBP, Université de Toulouse, CNRS, INRA, INSA, Toulouse, France. 135 av de Rangueil. 31077 Toulouse Cedex 4, France
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17
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Sinel C, Augagneur Y, Sassi M, Bronsard J, Cacaci M, Guérin F, Sanguinetti M, Meignen P, Cattoir V, Felden B. Small RNAs in vancomycin-resistant Enterococcus faecium involved in daptomycin response and resistance. Sci Rep 2017; 7:11067. [PMID: 28894187 PMCID: PMC5593968 DOI: 10.1038/s41598-017-11265-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 08/22/2017] [Indexed: 02/07/2023] Open
Abstract
Vancomycin-resistant Enterococcus faecium is a leading cause of hospital-acquired infections and outbreaks. Regulatory RNAs (sRNAs) are major players in adaptive responses, including antibiotic resistance. They were extensively studied in gram-negative bacteria, but less information is available for gram-positive pathogens. No sRNAs are described in E. faecium. We sought to identify a set of sRNAs expressed in vancomycin-resistant E. faecium Aus0004 strain to assess their roles in daptomycin response and resistance. Genomic and transcriptomic analyses revealed a set of 61 sRNA candidates, including 10 that were further tested and validated by Northern and qPCR. RNA-seq was performed with and without subinhibitory concentrations (SICs) of daptomycin, an antibiotic used to treat enterococcal infections. After daptomycin SIC exposure, the expression of 260 coding and srna genes was altered, with 80 upregulated and 180 downregulated, including 51% involved in carbohydrate and transport metabolisms. Daptomycin SIC exposure significantly affected the expression of seven sRNAs, including one experimentally confirmed, sRNA_0160. We studied sRNA expression in isogenic mutants with increasing levels of daptomycin resistance and observed that expression of several sRNAs, including sRNA_0160, was modified in the stepwise mutants. This first genome-wide sRNA identification in E. faecium suggests that some sRNAs are linked to antibiotic stress response and resistance.
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Affiliation(s)
- Clara Sinel
- University of Caen Normandie, EA4655, Caen, France
| | - Yoann Augagneur
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France
| | - Mohamed Sassi
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France
| | - Julie Bronsard
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France
| | - Margherita Cacaci
- Catholic University of Sacred Heart, Institute of Microbiology, Rome, Italy
| | - François Guérin
- University of Caen Normandie, EA4655, Caen, France.,Caen University Hospital, Department of Clinical Microbiology, Caen, France
| | | | - Pierrick Meignen
- University of Caen Normandie, IUT (department "STID"), Caen, France
| | - Vincent Cattoir
- University of Caen Normandie, EA4655, Caen, France. .,Caen University Hospital, Department of Clinical Microbiology, Caen, France. .,National Reference Center for Antimicrobial Resistance (lab Enterococci), Caen, France. .,Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France.
| | - Brice Felden
- Inserm U1230-Biochimie pharmaceutique, Rennes University, Rennes, France.
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18
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Hullahalli K, Rodrigues M, Palmer KL. Exploiting CRISPR-Cas to manipulate Enterococcus faecalis populations. eLife 2017; 6:e26664. [PMID: 28644125 PMCID: PMC5491264 DOI: 10.7554/elife.26664] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/15/2017] [Indexed: 12/21/2022] Open
Abstract
CRISPR-Cas provides a barrier to horizontal gene transfer in prokaryotes. It was previously observed that functional CRISPR-Cas systems are absent from multidrug-resistant (MDR) Enterococcus faecalis, which only possess an orphan CRISPR locus, termed CRISPR2, lacking cas genes. Here, we investigate how the interplay between CRISPR-Cas genome defense and antibiotic selection for mobile genetic elements shapes in vitro E. faecalis populations. We demonstrate that CRISPR2 can be reactivated for genome defense in MDR strains. Interestingly, we observe that E. faecalis transiently maintains CRISPR targets despite active CRISPR-Cas systems. Subsequently, if selection for the CRISPR target is present, toxic CRISPR spacers are lost over time, while in the absence of selection, CRISPR targets are lost over time. We find that forced maintenance of CRISPR targets induces a fitness cost that can be exploited to alter heterogeneous E. faecalis populations.
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Affiliation(s)
- Karthik Hullahalli
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, United States
| | - Marinelle Rodrigues
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, United States
| | - Kelli L Palmer
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, United States
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19
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Gawryszewska I, Malinowska K, Kuch A, Chrobak-Chmiel D, Trokenheim LL, Hryniewicz W, Sadowy E. Distribution of antimicrobial resistance determinants, virulence-associated factors and clustered regularly interspaced palindromic repeats loci in isolates of Enterococcus faecalis from various settings and genetic lineages. Pathog Dis 2017; 75:3059201. [PMID: 28334141 DOI: 10.1093/femspd/ftx021] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 02/24/2017] [Indexed: 12/17/2022] Open
Abstract
Enterococcus faecalis represents an important factor of hospital-associated infections (HAIs). The knowledge on its evolution from a commensal to an opportunistic pathogen is still limited; thus, we performed a study to characterise distribution of factors that may contribute to this adaptation. Using a collection obtained from various settings (hospitalised patients, community carriers, animals, fresh food, sewage, water), we investigated differences in antimicrobial susceptibility, distribution of antimicrobial resistance genes, virulence-associated determinants and phenotypes, and CRISPR loci in the context of the clonal relatedness of isolates. Bayesian Analysis of Population Structure revealed the presence of three major groups; two subgroups comprised almost exclusively HAI isolates, belonging to previously proposed enterococcal high-risk clonal complexes (HiRECCs) 6 and 28. Isolates of these two subgroups were significantly enriched in antimicrobial resistance genes, presumably produced a polysaccharide capsule and often carried the aggregation substance asa1; distribution of other virulence-associated genes, such as esp and cyl, formation of a biofilm and gelatinase production were more variable. Moreover, both subgroups showed a low prevalence of CRISPR-Cas 1 and 3 and presence of small CRISPR2 variants. Our study confirms the importance of HiRECCs in the population of E. faecalis and their confinement to the hospital settings.
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Affiliation(s)
- Iwona Gawryszewska
- Department of Molecular Microbiology, National Medicines Institute, 00-725 Warsaw, Poland
| | - Katarzyna Malinowska
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, 00-725 Warsaw, Poland
| | - Alicja Kuch
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, 00-725 Warsaw, Poland
| | - Dorota Chrobak-Chmiel
- Department of Preclinical Sciences, Faculty of Veterinary Medicine, Warsaw University of Life Sciences, 02-776 Warsaw, Poland
| | - Lucja Laniewska- Trokenheim
- Industrial and Food Microbiology, Faculty of Food Science, University of Warmia and Mazury, 10-726 Olsztyn, Poland
| | - Waleria Hryniewicz
- Department of Epidemiology and Clinical Microbiology, National Medicines Institute, 00-725 Warsaw, Poland
| | - Ewa Sadowy
- Department of Molecular Microbiology, National Medicines Institute, 00-725 Warsaw, Poland
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20
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Maes A, Gracia C, Innocenti N, Zhang K, Aurell E, Hajnsdorf E. Landscape of RNA polyadenylation in E. coli. Nucleic Acids Res 2017; 45:2746-2756. [PMID: 28426097 PMCID: PMC5389530 DOI: 10.1093/nar/gkw894] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 09/20/2016] [Accepted: 09/27/2016] [Indexed: 11/26/2022] Open
Abstract
Polyadenylation is thought to be involved in the degradation and quality control of bacterial RNAs but relatively few examples have been investigated. We used a combination of 5΄-tagRACE and RNA-seq to analyze the total RNA content from a wild-type strain and from a poly(A)polymerase deleted mutant. A total of 178 transcripts were either up- or down-regulated in the mutant when compared to the wild-type strain. Poly(A)polymerase up-regulates the expression of all genes related to the FliA regulon and several previously unknown transcripts, including numerous transporters. Notable down-regulation of genes in the expression of antigen 43 and components of the type 1 fimbriae was detected. The major consequence of the absence of poly(A)polymerase was the accumulation of numerous sRNAs, antisense transcripts, REP sequences and RNA fragments resulting from the processing of entire transcripts. A new algorithm to analyze the position and composition of post-transcriptional modifications based on the sequence of unencoded 3΄-ends, was developed to identify polyadenylated molecules. Overall our results shed new light on the broad spectrum of action of polyadenylation on gene expression and demonstrate the importance of poly(A) dependent degradation to remove structured RNA fragments.
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Affiliation(s)
- Alexandre Maes
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue P. et M. Curie, 75005 Paris, France
| | - Céline Gracia
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue P. et M. Curie, 75005 Paris, France
| | - Nicolas Innocenti
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, Roslagstullsbacken 17, SE-10691 Stockholm, Sweden
- Combient AB, Nettovägen 6, SE-175 41 Järfälla, Sweden
| | - Kaiyang Zhang
- Systems Biology Laboratory, Research Programs Unit,Genome-Scale Biology, Faculty of Medicine, University of Helsinki, Helsinki, FIN-00014, Finlandepts of Computer Science and Applied Physics, Aalto University, Konemiehentie 2, FI-02150 Espoo, Finland
| | - Erik Aurell
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, Roslagstullsbacken 17, SE-10691 Stockholm, Sweden
- Departments of Computer Science and Applied Physics, AaltoUniversity, Konemiehentie 2, FI-02150 Espoo, Finlandombient AB, Nettovägen 6, SE-175 41 Järfälla, Sweden
| | - Eliane Hajnsdorf
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 13 rue P. et M. Curie, 75005 Paris, France
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21
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Cho S, Kim MS, Jeong Y, Lee BR, Lee JH, Kang SG, Cho BK. Genome-wide primary transcriptome analysis of H 2-producing archaeon Thermococcus onnurineus NA1. Sci Rep 2017; 7:43044. [PMID: 28216628 PMCID: PMC5316973 DOI: 10.1038/srep43044] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/18/2017] [Indexed: 01/09/2023] Open
Abstract
In spite of their pivotal roles in transcriptional and post-transcriptional processes, the regulatory elements of archaeal genomes are not yet fully understood. Here, we determine the primary transcriptome of the H2-producing archaeon Thermococcus onnurineus NA1. We identified 1,082 purine-rich transcription initiation sites along with well-conserved TATA box, A-rich B recognition element (BRE), and promoter proximal element (PPE) motif in promoter regions, a high pyrimidine nucleotide content (T/C) at the -1 position, and Shine-Dalgarno (SD) motifs (GGDGRD) in 5' untranslated regions (5' UTRs). Along with differential transcript levels, 117 leaderless genes and 86 non-coding RNAs (ncRNAs) were identified, representing diverse cellular functions and potential regulatory functions under the different growth conditions. Interestingly, we observed low GC content in ncRNAs for RNA-based regulation via unstructured forms or interaction with other cellular components. Further comparative analysis of T. onnurineus upstream regulatory sequences with those of closely related archaeal genomes demonstrated that transcription of orthologous genes are initiated by highly conserved promoter sequences, however their upstream sequences for transcriptional and translational regulation are largely diverse. These results provide the genetic information of T. onnurineus for its future application in metabolic engineering.
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Affiliation(s)
- Suhyung Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Min-Sik Kim
- Korea Institute of Ocean Science and Technology, Ansan 426-744, Republic of Korea
| | - Yujin Jeong
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
| | - Bo-Rahm Lee
- Intelligent Synthetic Biology Center, Daejeon 305-701, Republic of Korea
| | - Jung-Hyun Lee
- Korea Institute of Ocean Science and Technology, Ansan 426-744, Republic of Korea
| | - Sung Gyun Kang
- Korea Institute of Ocean Science and Technology, Ansan 426-744, Republic of Korea
| | - Byung-Kwan Cho
- Department of Biological Sciences and KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea
- Intelligent Synthetic Biology Center, Daejeon 305-701, Republic of Korea
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Fontaine F, Gasiorowski E, Gracia C, Ballouche M, Caillet J, Marchais A, Hajnsdorf E. The small RNA SraG participates in PNPase homeostasis. RNA (NEW YORK, N.Y.) 2016; 22:1560-1573. [PMID: 27495318 PMCID: PMC5029454 DOI: 10.1261/rna.055236.115] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 06/24/2016] [Indexed: 06/06/2023]
Abstract
The rpsO-pnp operon encodes ribosomal protein S15 and polynucleotide phosphorylase, a major 3'-5' exoribonuclease involved in mRNA decay in Escherichia coli The gene for the SraG small RNA is located between the coding regions of the rpsO and pnp genes, and it is transcribed in the opposite direction relative to the two genes. No function has been assigned to SraG. Multiple levels of post-transcriptional regulation have been demonstrated for the rpsO-pnp operon. Here we show that SraG is a new factor affecting pnp expression. SraG overexpression results in a reduction of pnp expression and a destabilization of pnp mRNA; in contrast, inhibition of SraG transcription results in a higher level of the pnp transcript. Furthermore, in vitro experiments indicate that SraG inhibits translation initiation of pnp Together, these observations demonstrate that SraG participates in the post-transcriptional control of pnp by a direct antisense interaction between SraG and PNPase RNAs. Our data reveal a new level of regulation in the expression of this major exoribonuclease.
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Affiliation(s)
- Fanette Fontaine
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Elise Gasiorowski
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Celine Gracia
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Mathieu Ballouche
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Joel Caillet
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
| | - Antonin Marchais
- Institut de Génétique et Microbiologie, CNRS/UMR 8621, Université Paris Sud, 91405 Orsay, France
| | - Eliane Hajnsdorf
- CNRS UMR8261 (previously FRE3630) associated with University Paris Diderot, Sorbonne Paris Cité, Institut de Biologie Physico-Chimique, 75005 Paris, France
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23
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Innocenti N, Repoila F, Aurell E. Detection and quantitative estimation of spurious double stranded DNA formation during reverse transcription in bacteria using tagRNA-seq. RNA Biol 2016; 12:1067-9. [PMID: 26177062 DOI: 10.1080/15476286.2015.1071010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Standard RNA-seq has a well know tendency to generate "ghost" antisense reads due to formation of spurious second strand cDNA in the sequencing process. We recently reported on a novel variant of RNA-seq coined "tagRNA-seq" introduced for the purpose of distinguishing primary from processed transcripts in bacteria. Incidentally, the additional information provided by the tags is also very suitable for detection of true anti-sense RNA transcripts and quantification of spurious antisense signals in a sample. We briefly explain how to perform such a detection and illustrate on previously published datasets.
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Affiliation(s)
- Nicolas Innocenti
- a Department of Computational Biology ; KTH Royal Institute of Technology; AlbaNova University Center ; Stockholm , Sweden
| | - Francis Repoila
- b INRA; UMR1319 Micalis; Domaine de Vilvert ; Jouy-en-Josas , France.,c AgroParisTech; UMR Micalis; Domaine de Vilvert ; Jouy-en-Josas , France
| | - Erik Aurell
- a Department of Computational Biology ; KTH Royal Institute of Technology; AlbaNova University Center ; Stockholm , Sweden.,d Department of Information and Computer Science ; Aalto University ; Espoo , Finland
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24
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The dynamic transcriptional and translational landscape of the model antibiotic producer Streptomyces coelicolor A3(2). Nat Commun 2016; 7:11605. [PMID: 27251447 PMCID: PMC4895711 DOI: 10.1038/ncomms11605] [Citation(s) in RCA: 138] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 04/12/2016] [Indexed: 02/08/2023] Open
Abstract
Individual Streptomyces species have the genetic potential to produce a diverse array of natural products of commercial, medical and veterinary interest. However, these products are often not detectable under laboratory culture conditions. To harness their full biosynthetic potential, it is important to develop a detailed understanding of the regulatory networks that orchestrate their metabolism. Here we integrate nucleotide resolution genome-scale measurements of the transcriptome and translatome of Streptomyces coelicolor, the model antibiotic-producing actinomycete. Our systematic study determines 3,570 transcription start sites and identifies 230 small RNAs and a considerable proportion (∼21%) of leaderless mRNAs; this enables deduction of genome-wide promoter architecture. Ribosome profiling reveals that the translation efficiency of secondary metabolic genes is negatively correlated with transcription and that several key antibiotic regulatory genes are translationally induced at transition growth phase. These findings might facilitate the design of new approaches to antibiotic discovery and development.
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CRISPR-Cas and Restriction-Modification Act Additively against Conjugative Antibiotic Resistance Plasmid Transfer in Enterococcus faecalis. mSphere 2016; 1:mSphere00064-16. [PMID: 27303749 PMCID: PMC4894674 DOI: 10.1128/msphere.00064-16] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 04/12/2016] [Indexed: 12/12/2022] Open
Abstract
Enterococcus faecalis is a bacterium that normally inhabits the gastrointestinal tracts of humans and other animals. Although these bacteria are members of our native gut flora, they can cause life-threatening infections in hospitalized patients. Antibiotic resistance genes appear to be readily shared among high-risk E. faecalis strains, and multidrug resistance in these bacteria limits treatment options for infections. Here, we find that CRISPR-Cas and restriction-modification systems, which function as adaptive and innate immune systems in bacteria, significantly impact the spread of antibiotic resistance genes in E. faecalis populations. The loss of these systems in high-risk E. faecalis suggests that they are immunocompromised, a tradeoff that allows them to readily acquire new genes and adapt to new antibiotics. Enterococcus faecalis is an opportunistic pathogen and a leading cause of nosocomial infections. Conjugative pheromone-responsive plasmids are narrow-host-range mobile genetic elements (MGEs) that are rapid disseminators of antibiotic resistance in the faecalis species. Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas and restriction-modification confer acquired and innate immunity, respectively, against MGE acquisition in bacteria. Most multidrug-resistant E. faecalis isolates lack CRISPR-Cas and possess an orphan locus lacking cas genes, CRISPR2, that is of unknown function. Little is known about restriction-modification defense in E. faecalis. Here, we explore the hypothesis that multidrug-resistant E. faecalis strains are immunocompromised. We assessed MGE acquisition by E. faecalis T11, a strain closely related to the multidrug-resistant hospital isolate V583 but which lacks the ~620 kb of horizontally acquired genome content that characterizes V583. T11 possesses the E. faecalis CRISPR3-cas locus and a predicted restriction-modification system, neither of which occurs in V583. We demonstrate that CRISPR-Cas and restriction-modification together confer a 4-log reduction in acquisition of the pheromone-responsive plasmid pAM714 in biofilm matings. Additionally, we show that the orphan CRISPR2 locus is functional for genome defense against another pheromone-responsive plasmid, pCF10, only in the presence of cas9 derived from the E. faecalis CRISPR1-cas locus, which most multidrug-resistant E. faecalis isolates lack. Overall, our work demonstrated that the loss of only two loci led to a dramatic reduction in genome defense against a clinically relevant MGE, highlighting the critical importance of the E. faecalis accessory genome in modulating horizontal gene transfer. Our results rationalize the development of antimicrobial strategies that capitalize upon the immunocompromised status of multidrug-resistant E. faecalis. IMPORTANCEEnterococcus faecalis is a bacterium that normally inhabits the gastrointestinal tracts of humans and other animals. Although these bacteria are members of our native gut flora, they can cause life-threatening infections in hospitalized patients. Antibiotic resistance genes appear to be readily shared among high-risk E. faecalis strains, and multidrug resistance in these bacteria limits treatment options for infections. Here, we find that CRISPR-Cas and restriction-modification systems, which function as adaptive and innate immune systems in bacteria, significantly impact the spread of antibiotic resistance genes in E. faecalis populations. The loss of these systems in high-risk E. faecalis suggests that they are immunocompromised, a tradeoff that allows them to readily acquire new genes and adapt to new antibiotics.
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26
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Wessner F, Lacoux C, Goeders N, Fouquier d'Hérouel A, Matos R, Serror P, Van Melderen L, Repoila F. Regulatory crosstalk between type I and type II toxin-antitoxin systems in the human pathogen Enterococcus faecalis. RNA Biol 2015; 12:1099-108. [PMID: 26305399 DOI: 10.1080/15476286.2015.1084465] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
We discovered a chromosomal locus containing 2 toxin-antitoxin modules (TAs) with an antisense transcriptional organization in the E. faecalis clinical isolate V583. These TAs are homologous to the type I txpA-ratA system and the type II mazEF, respectively. We have shown that the putative MazF is toxic for E. coli and triggers RNA degradation, and its cognate antitoxin MazE counteracts toxicity. The second module, adjacent to mazEF, expresses a toxin predicted to belong to the TxpA type I family found in Firmicutes, and the antisense RNA antidote, RatA. Genomic analysis indicates that the cis-association of mazEF and txpA-ratA modules has been favored during evolution, suggesting a selective advantage for this TA organization in the E. faecalis species. We showed regulatory interplays between the 2 modules, involving transcription control and RNA stability. Remarkably, our data reveal that MazE and MazEF have a dual transcriptional activity: they act as autorepressors and activate ratA transcription, most likely in a direct manner. RatA controls txpA RNA levels through stability. Our data suggest a pivotal role of MazEF in the coordinated expression of mazEF and txpA-ratA modules in V583. To our knowledge, this is the first report describing a crosstalk between type I and II TAs.
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Affiliation(s)
- Françoise Wessner
- a INRA UMR1319 Micalis ; Jouy-en-Josas , France.,b AgroParisTech, UMR Micalis ; Jouy-en-Josas , France
| | - Caroline Lacoux
- a INRA UMR1319 Micalis ; Jouy-en-Josas , France.,b AgroParisTech, UMR Micalis ; Jouy-en-Josas , France
| | - Nathalie Goeders
- c Université Libre de Bruxelles, Faculté des Sciences, Institut de Biologie et Médecine Moléculaire ; Gosselies , Belgium
| | | | - Renata Matos
- a INRA UMR1319 Micalis ; Jouy-en-Josas , France.,b AgroParisTech, UMR Micalis ; Jouy-en-Josas , France
| | - Pascale Serror
- a INRA UMR1319 Micalis ; Jouy-en-Josas , France.,b AgroParisTech, UMR Micalis ; Jouy-en-Josas , France
| | - Laurence Van Melderen
- c Université Libre de Bruxelles, Faculté des Sciences, Institut de Biologie et Médecine Moléculaire ; Gosselies , Belgium
| | - Francis Repoila
- a INRA UMR1319 Micalis ; Jouy-en-Josas , France.,b AgroParisTech, UMR Micalis ; Jouy-en-Josas , France
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27
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Cortes-Perez NG, Dumoulin R, Gaubert S, Lacoux C, Bugli F, Martin R, Chat S, Piquand K, Meylheuc T, Langella P, Sanguinetti M, Posteraro B, Rigottier-Gois L, Serror P. Overexpression of Enterococcus faecalis elr operon protects from phagocytosis. BMC Microbiol 2015; 15:112. [PMID: 26003173 PMCID: PMC4522977 DOI: 10.1186/s12866-015-0448-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 05/14/2015] [Indexed: 11/17/2022] Open
Abstract
Background Mechanisms underlying the transition from commensalism to virulence in Enterococcus faecalis are not fully understood. We previously identified the enterococcal leucine-rich protein A (ElrA) as a virulence factor of E. faecalis. The elrA gene is part of an operon that comprises four other ORFs encoding putative surface proteins of unknown function. Results In this work, we compared the susceptibility to phagocytosis of three E. faecalis strains, including a wild-type (WT), a ΔelrA strain, and a strain overexpressing the whole elr operon in order to understand the role of this operon in E. faecalis virulence. While both WT and ΔelrA strains were efficiently phagocytized by RAW 264.7 mouse macrophages, the elr operon-overexpressing strain showed a decreased capability to be internalized by the phagocytic cells. Consistently, the strain overexpressing elr operon was less adherent to macrophages than the WT strain, suggesting that overexpression of the elr operon could confer E. faecalis with additional anti-adhesion properties. In addition, increased virulence of the elr operon-overexpressing strain was shown in a mouse peritonitis model. Conclusions Altogether, our results indicate that overexpression of the elr operon facilitates the E. faecalis escape from host immune defenses. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0448-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Naima G Cortes-Perez
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France. .,Current address: INRA, Unité d'Immuno-Allergie Alimentaire, iBiTecS/SPI, Gif-sur-Yvette, France.
| | - Romain Dumoulin
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Stéphane Gaubert
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Caroline Lacoux
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Francesca Bugli
- Institute of Microbiology, Università Cattolica del Sacro Cuore, Rome, Italy.
| | - Rebeca Martin
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Sophie Chat
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Kevin Piquand
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Thierry Meylheuc
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Philippe Langella
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | | | - Brunella Posteraro
- Institute of Public Health (Section of Hygiene), Università Cattolica del Sacro Cuore, Rome, Italy.
| | - Lionel Rigottier-Gois
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
| | - Pascale Serror
- INRA, UMR1319 Micalis, Jouy-en-Josas, France. .,AgroParisTech, UMR1319 Micalis, Jouy-en-Josas, France.
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28
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Innocenti N, Golumbeanu M, Fouquier d'Hérouël A, Lacoux C, Bonnin RA, Kennedy SP, Wessner F, Serror P, Bouloc P, Repoila F, Aurell E. Whole-genome mapping of 5' RNA ends in bacteria by tagged sequencing: a comprehensive view in Enterococcus faecalis. RNA (NEW YORK, N.Y.) 2015; 21:1018-30. [PMID: 25737579 PMCID: PMC4408782 DOI: 10.1261/rna.048470.114] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 12/22/2014] [Indexed: 05/21/2023]
Abstract
Enterococcus faecalis is the third cause of nosocomial infections. To obtain the first snapshot of transcriptional organizations in this bacterium, we used a modified RNA-seq approach enabling to discriminate primary from processed 5' RNA ends. We also validated our approach by confirming known features in Escherichia coli. We mapped 559 transcription start sites (TSSs) and 352 processing sites (PSSs) in E. faecalis. A blind motif search retrieved canonical features of SigA- and SigN-dependent promoters preceding transcription start sites mapped. We discovered 85 novel putative regulatory RNAs, small- and antisense RNAs, and 72 transcriptional antisense organizations. Presented data constitute a significant insight into bacterial RNA landscapes and a step toward the inference of regulatory processes at transcriptional and post-transcriptional levels in a comprehensive manner.
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Affiliation(s)
- Nicolas Innocenti
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Monica Golumbeanu
- Department of Biosystems Science and Engineering, ETH Zürich, CH-4058, Basel, Switzerland SIB Swiss Institute of Bioinformatics, University of Basel, CH-4056, Basel, Switzerland
| | - Aymeric Fouquier d'Hérouël
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden Luxembourg Centre for Systems Biomedicine, University of Luxembourg, L-4362, Esch-sur-Alzette, Luxembourg
| | - Caroline Lacoux
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Rémy A Bonnin
- Institut de Génétique et Microbiologie, Université Paris-Sud, CNRS, UMR8621, F-91405, Orsay, France
| | - Sean P Kennedy
- INRA, MetaGenoPolis US1367, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Françoise Wessner
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Pascale Serror
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Philippe Bouloc
- Institut de Génétique et Microbiologie, Université Paris-Sud, CNRS, UMR8621, F-91405, Orsay, France
| | - Francis Repoila
- INRA, UMR1319 Micalis, Domaine de Vilvert, F-78352, Jouy-en-Josas, France AgroParisTech, UMR Micalis, Domaine de Vilvert, F-78350, Jouy-en-Josas, France
| | - Erik Aurell
- Department of Computational Biology, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden Department of Information and Computer Science, Aalto University, FI-02150 Espoo, Finland
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29
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Li J, Qi L, Guo Y, Yue L, Li Y, Ge W, Wu J, Shi W, Dong X. Global mapping transcriptional start sites revealed both transcriptional and post-transcriptional regulation of cold adaptation in the methanogenic archaeon Methanolobus psychrophilus. Sci Rep 2015; 5:9209. [PMID: 25784521 PMCID: PMC5378194 DOI: 10.1038/srep09209] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/23/2015] [Indexed: 11/12/2022] Open
Abstract
Psychrophilic methanogenic Archaea contribute significantly to global methane emissions, but archaeal cold adaptation mechanisms remain poorly understood. Hinted by that mRNA architecture determined secondary structure respond to cold more promptly than proteins, differential RNA-seq was used in this work to examine the genome-wide transcription start sites (TSSs) of the psychrophilic methanogen Methanolobus psychrophilus R15 and its response to cold. Unlike most prokaryotic mRNAs with short 5' untranslated regions (5' UTR, median lengths of 20-40 nt), 51% mRNAs of this methanogen have large 5' UTR (>50 nt). For 24% of the mRNAs, the 5' UTR is >150 nt. This implies that post-transcriptional regulation may be significance in the psychrophile. Remarkably, 219 (14%) genes possessed multiple gene TSSs (gTSSs), and 84 genes exhibited temperature-regulated gTSS selection to express alternative 5' UTR. Primer extension studies confirmed the temperature-dependent TSS selection and a stem-loop masking of ribosome binding sites was predicted from the longer 5' UTRs, suggesting alternative 5' UTRs-mediated translation regulation in the cold adaptation as well. In addition, 195 small RNAs (sRNAs) were detected, and Northern blots confirmed that many sRNAs were induced by cold. Thus, this study revealed an integrated transcriptional and post-transcriptional regulation for cold adaptation in a psychrophilic methanogen.
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Affiliation(s)
- Jie Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Beijing 100101, People's Republic of China
| | - Lei Qi
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Beijing 100101, People's Republic of China
| | - Yang Guo
- Novogene Bioinformatics Institute, 21st Floor, Jinma building B area, Xueqing Road, Beijing 100083, People's Republic of China
| | - Lei Yue
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Beijing 100101, People's Republic of China
| | - Yanping Li
- Novogene Bioinformatics Institute, 21st Floor, Jinma building B area, Xueqing Road, Beijing 100083, People's Republic of China
| | - Weizhen Ge
- Novogene Bioinformatics Institute, 21st Floor, Jinma building B area, Xueqing Road, Beijing 100083, People's Republic of China
| | - Jun Wu
- Novogene Bioinformatics Institute, 21st Floor, Jinma building B area, Xueqing Road, Beijing 100083, People's Republic of China
| | - Wenyuan Shi
- Department of Microbiology, Immunology and Molecular Genetics, University of California, 10833 Le Conte Avenue, Los Angeles, CA90095, USA
| | - Xiuzhu Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No.1 Beichen West Road, Beijing 100101, People's Republic of China
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30
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Tsai CH, Liao R, Chou B, Palumbo M, Contreras LM. Genome-wide analyses in bacteria show small-RNA enrichment for long and conserved intergenic regions. J Bacteriol 2015; 197:40-50. [PMID: 25313390 PMCID: PMC4288687 DOI: 10.1128/jb.02359-14] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 10/02/2014] [Indexed: 12/21/2022] Open
Abstract
Interest in finding small RNAs (sRNAs) in bacteria has significantly increased in recent years due to their regulatory functions. Development of high-throughput methods and more sophisticated computational algorithms has allowed rapid identification of sRNA candidates in different species. However, given their various sizes (50 to 500 nucleotides [nt]) and their potential genomic locations in the 5' and 3' untranslated regions as well as in intergenic regions, identification and validation of true sRNAs have been challenging. In addition, the evolution of bacterial sRNAs across different species continues to be puzzling, given that they can exert similar functions with various sequences and structures. In this study, we analyzed the enrichment patterns of sRNAs in 13 well-annotated bacterial species using existing transcriptome and experimental data. All intergenic regions were analyzed by WU-BLAST to examine conservation levels relative to species within or outside their genus. In total, more than 900 validated bacterial sRNAs and 23,000 intergenic regions were analyzed. The results indicate that sRNAs are enriched in intergenic regions, which are longer and more conserved than the average intergenic regions in the corresponding bacterial genome. We also found that sRNA-coding regions have different conservation levels relative to their flanking regions. This work provides a way to analyze how noncoding RNAs are distributed in bacterial genomes and also shows conserved features of intergenic regions that encode sRNAs. These results also provide insight into the functions of regions surrounding sRNAs and into optimization of RNA search algorithms.
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Affiliation(s)
- Chen-Hsun Tsai
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Rick Liao
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Brendan Chou
- Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas, USA
| | - Michael Palumbo
- Computational Biology and Statistics, Wadsworth Center, Albany, New York, USA
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA
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Involvement of Enterococcus faecalis small RNAs in stress response and virulence. Infect Immun 2014; 82:3599-611. [PMID: 24914223 DOI: 10.1128/iai.01900-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Candidate small RNAs (sRNAs) have recently been identified in Enterococcus faecalis, a Gram-positive opportunistic pathogen, and six of these candidate sRNAs with unknown functions were selected for a functional study. Deletion mutants and complemented strains were constructed, and their virulence was tested. We were unable to obtain the ef0869-0870 mutant, likely due to an essential role, and the ef0820-0821 sRNA seemed not to be involved in virulence. In contrast, the mutant lacking ef0408-0409 sRNA, homologous to the RNAII component of the toxin-antitoxin system, appeared more virulent and more able to colonize mouse organs. The three other mutants showed reduced virulence. In addition, we checked the responses of these mutant strains to several stresses encountered in the gastrointestinal tract or during the infection process. In parallel, the activities of the sRNA promoters were measured using transcriptional fusion constructions. To attempt to identify the regulons of these candidate sRNAs, proteomics profiles of the mutant strains were compared with that of the wild type. This showed that the selected sRNAs controlled the expression of proteins involved in diverse cellular processes and the stress response. The combined data highlight the roles of certain candidate sRNAs in the adaptation of E. faecalis to environmental changes and in the complex transition process from a commensal to a pathogen.
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Abstract
Small regulatory RNAs (sRNAs) that act by base-pairing were first discovered in so-called accessory DNA elements—plasmids, phages, and transposons—where they control replication, maintenance, and transposition. Since 2001, a huge body of work has been performed to predict and identify sRNAs in a multitude of bacterial genomes. The majority of chromosome-encoded sRNAs have been investigated in E. coli and other Gram-negative bacteria. However, during the past five years an increasing number of sRNAs were found in Gram-positive bacteria. Here, we outline our current knowledge on chromosome-encoded sRNAs from low-GC Gram-positive species that act by base-pairing, i.e., an antisense mechanism. We will focus on sRNAs with known targets and defined regulatory mechanisms with special emphasis on Bacillus subtilis.
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Affiliation(s)
- Sabine Brantl
- Friedrich-Schiller-Universität Jena; Biologisch-Pharmazeutische Fakultät; AG Bakteriengenetik; Philosophenweg 12; Jena, Germany
| | - Reinhold Brückner
- Mikrobiologie; TU Kaiserslautern; Paul-Ehrlich-Str. 23; D-67663 Kaiserslautern, Germany
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Meyrand M, Guillot A, Goin M, Furlan S, Armalyte J, Kulakauskas S, Cortes-Perez NG, Thomas G, Chat S, Péchoux C, Dupres V, Hols P, Dufrêne YF, Trugnan G, Chapot-Chartier MP. Surface proteome analysis of a natural isolate of Lactococcus lactis reveals the presence of pili able to bind human intestinal epithelial cells. Mol Cell Proteomics 2013; 12:3935-47. [PMID: 24002364 DOI: 10.1074/mcp.m113.029066] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Surface proteins of Gram-positive bacteria play crucial roles in bacterial adhesion to host tissues. Regarding commensal or probiotic bacteria, adhesion to intestinal mucosa may promote their persistence in the gastro-intestinal tract and their beneficial effects to the host. In this study, seven Lactococcus lactis strains exhibiting variable surface physico-chemical properties were compared for their adhesion to Caco-2 intestinal epithelial cells. In this test, only one vegetal isolate TIL448 expressed a high-adhesion phenotype. A nonadhesive derivative was obtained by plasmid curing from TIL448, indicating that the adhesion determinants were plasmid-encoded. Surface-exposed proteins in TIL448 were analyzed by a proteomic approach consisting in shaving of the bacterial surface with trypsin and analysis of the released peptides by LC-MS/MS. As the TIL448 complete genome sequence was not available, the tryptic peptides were identified by a mass matching approach against a database including all Lactococcus protein sequences and the sequences deduced from partial DNA sequences of the TIL448 plasmids. Two surface proteins, encoded by plasmids in TIL448, were identified as candidate adhesins, the first one displaying pilin characteristics and the second one containing two mucus-binding domains. Inactivation of the pilin gene abolished adhesion to Caco-2 cells whereas inactivation of the mucus-binding protein gene had no effect on adhesion. The pilin gene is located inside a cluster of four genes encoding two other pilin-like proteins and one class-C sortase. Synthesis of pili was confirmed by immunoblotting detection of high molecular weight forms of pilins associated to the cell wall as well as by electron and atomic force microscopy observations. As a conclusion, surface proteome analysis allowed us to detect pilins at the surface of L. lactis TIL448. Moreover we showed that pili appendages are formed and involved in adhesion to Caco-2 intestinal epithelial cells.
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Rochat T, Bouloc P, Repoila F. Gene expression control by selective RNA processing and stabilization in bacteria. FEMS Microbiol Lett 2013; 344:104-13. [PMID: 23617839 DOI: 10.1111/1574-6968.12162] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 04/22/2013] [Indexed: 11/27/2022] Open
Abstract
RNA maturation is a key event regulating genes at post-transcriptional level. In bacteria, it is employed to adjust the amounts of proteins and functional RNAs, often in response to environmental constraints. During the process of RNA maturation, enzymes and factors that would otherwise promote RNA degradation convert a labile RNA into a stable and biologically functional molecule.
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Affiliation(s)
- Tatiana Rochat
- INRA, UR892, Virologie et Immunologie Moléculaires, Jouy-en-Josas, France
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Enterococcal Rgg-like regulator ElrR activates expression of the elrA operon. J Bacteriol 2013; 195:3073-83. [PMID: 23645602 DOI: 10.1128/jb.00121-13] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The Enterococcus faecalis leucine-rich protein ElrA promotes virulence by stimulating bacterial persistence in macrophages and production of the interleukin-6 (IL-6) cytokine. The ElrA protein is encoded within an operon that is poorly expressed under laboratory conditions but induced in vivo. In this study, we identify ef2687 (renamed elrR), which encodes a member of the Rgg (regulator gene for glucosyltransferase) family of putative regulatory proteins. Using quantitative reverse transcription-PCR, translational lacZ fusions, and electrophoretic mobility shift assays, we demonstrate that ElrR positively regulates expression of elrA. These results correlate with the attenuated virulence of the ΔelrR strain in a mouse peritonitis model. Virulence of simple and double elrR and elrA deletion mutants also suggests a remaining ElrR-independent expression of elrA in vivo and additional virulence-related genes controlled by ElrR.
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Werner G, Coque TM, Franz CMAP, Grohmann E, Hegstad K, Jensen L, van Schaik W, Weaver K. Antibiotic resistant enterococci-tales of a drug resistance gene trafficker. Int J Med Microbiol 2013; 303:360-79. [PMID: 23602510 DOI: 10.1016/j.ijmm.2013.03.001] [Citation(s) in RCA: 116] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Enterococci have been recognized as important hospital-acquired pathogens in recent years, and isolates of E. faecalis and E. faecium are the third- to fourth-most prevalent nosocomial pathogen worldwide. Acquired resistances, especially against penicilin/ampicillin, aminoglycosides (high-level) and glycopeptides are therapeutically important and reported in increasing numbers. On the other hand, isolates of E. faecalis and E. faecium are commensals of the intestines of humans, many vertebrate and invertebrate animals and may also constitute an active part of the plant flora. Certain enterococcal isolates are used as starter cultures or supplements in food fermentation and food preservation. Due to their preferred intestinal habitat, their wide occurrence, robustness and ease of cultivation, enterococci are used as indicators for fecal pollution assessing hygiene standards for fresh- and bathing water and they serve as important key indicator bacteria for various veterinary and human resistance surveillance systems. Enterococci are widely prevalent and genetically capable of acquiring, conserving and disseminating genetic traits including resistance determinants among enterococci and related Gram-positive bacteria. In the present review we aimed at summarizing recent advances in the current understanding of the population biology of enterococci, the role mobile genetic elements including plasmids play in shaping the population structure and spreading resistance. We explain how these elements could be classified and discuss mechanisms of plasmid transfer and regulation and the role and cross-talk of enterococcal isolates from food and food animals to humans.
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Affiliation(s)
- Guido Werner
- National Reference Centre for Stapyhlococci and Enterococci, Division of Nosocomial Pathogens and Antibiotic Resistances, Robert Koch Institute, Wernigerode Branch, Burgstr. 37, 38855 Wernigerode, Germany.
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Fontaine L, Goffin P, Dubout H, Delplace B, Baulard A, Lecat-Guillet N, Chambellon E, Gardan R, Hols P. Mechanism of competence activation by the ComRS signalling system in streptococci. Mol Microbiol 2013; 87:1113-32. [PMID: 23323845 DOI: 10.1111/mmi.12157] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/09/2013] [Indexed: 11/28/2022]
Abstract
In many streptococci, competence for natural DNA transformation is regulated by the Rgg-type regulator ComR and the pheromone ComS, which is sensed intracellularly. We compared the ComRS systems of four model streptococcal species using in vitro and in silico approaches, to determine the mechanism of the ComRS-dependent regulation of competence. In all systems investigated, ComR was shown to be the proximal transcriptional activator of the expression of key competence genes. Efficient binding of ComR to DNA is strictly dependent on the presence of the pheromone (C-terminal ComS octapeptide), in contrast with other streptococcal Rgg-type regulators. The 20 bp palindromic ComR-box is the minimal genetic requirement for binding of ComR, and its sequence directly determines the expression level of genes under its control. Despite the apparent species-specific specialization of the ComR-ComS interaction, mutagenesis of ComS residues from Streptococcus thermophilus highlighted an unexpected permissiveness with respect to its biological activity. In agreement, heterologous ComS, and even primary sequence-unrelated, casein-derived octapeptides, were able to induce competence development in S. thermophilus. The lack of stringency of ComS sequence suggests that competence of a specific Streptococcus species may be modulated by other streptococci or by non-specific nutritive oligopeptides present in its environment.
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Affiliation(s)
- Laetitia Fontaine
- Biochimie et Génétique Moléculaire Bactérienne, Institut des Sciences de la Vie, Université catholique de Louvain, B-1348, Louvain-la-Neuve, Belgium.
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Weiss V, Medina-Rivera A, Huerta AM, Santos-Zavaleta A, Salgado H, Morett E, Collado-Vides J. Evidence classification of high-throughput protocols and confidence integration in RegulonDB. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2013; 2013:bas059. [PMID: 23327937 PMCID: PMC3548332 DOI: 10.1093/database/bas059] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
RegulonDB provides curated information on the transcriptional regulatory network of Escherichia coli and contains both experimental data and computationally predicted objects. To account for the heterogeneity of these data, we introduced in version 6.0, a two-tier rating system for the strength of evidence, classifying evidence as either ‘weak’ or ‘strong’ (Gama-Castro,S., Jimenez-Jacinto,V., Peralta-Gil,M. et al. RegulonDB (Version 6.0): gene regulation model of Escherichia Coli K-12 beyond transcription, active (experimental) annotated promoters and textpresso navigation. Nucleic Acids Res., 2008;36:D120–D124.). We now add to our classification scheme the classification of high-throughput evidence, including chromatin immunoprecipitation (ChIP) and RNA-seq technologies. To integrate these data into RegulonDB, we present two strategies for the evaluation of confidence, statistical validation and independent cross-validation. Statistical validation involves verification of ChIP data for transcription factor-binding sites, using tools for motif discovery and quality assessment of the discovered matrices. Independent cross-validation combines independent evidence with the intention to mutually exclude false positives. Both statistical validation and cross-validation allow to upgrade subsets of data that are supported by weak evidence to a higher confidence level. Likewise, cross-validation of strong confidence data extends our two-tier rating system to a three-tier system by introducing a third confidence score ‘confirmed’. Database URL:http://regulondb.ccg.unam.mx/
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Affiliation(s)
- Verena Weiss
- Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, AP 565-A, Cuernavaca, Morelos 62100, Mexico.
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Pischimarov J, Kuenne C, Billion A, Hemberger J, Cemič F, Chakraborty T, Hain T. sRNAdb: a small non-coding RNA database for gram-positive bacteria. BMC Genomics 2012; 13:384. [PMID: 22883983 PMCID: PMC3439263 DOI: 10.1186/1471-2164-13-384] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Accepted: 07/01/2012] [Indexed: 11/16/2022] Open
Abstract
Background The class of small non-coding RNA molecules (sRNA) regulates gene expression by different mechanisms and enables bacteria to mount a physiological response due to adaptation to the environment or infection. Over the last decades the number of sRNAs has been increasing rapidly. Several databases like Rfam or fRNAdb were extended to include sRNAs as a class of its own. Furthermore new specialized databases like sRNAMap (gram-negative bacteria only) and sRNATarBase (target prediction) were established. To the best of the authors’ knowledge no database focusing on sRNAs from gram-positive bacteria is publicly available so far. Description In order to understand sRNA’s functional and phylogenetic relationships we have developed sRNAdb and provide tools for data analysis and visualization. The data compiled in our database is assembled from experiments as well as from bioinformatics analyses. The software enables comparison and visualization of gene loci surrounding the sRNAs of interest. To accomplish this, we use a client–server based approach. Offline versions of the database including analyses and visualization tools can easily be installed locally on the user’s computer. This feature facilitates customized local addition of unpublished sRNA candidates and related information such as promoters or terminators using tab-delimited files. Conclusion sRNAdb allows a user-friendly and comprehensive comparative analysis of sRNAs from available sequenced gram-positive prokaryotic replicons. Offline versions including analysis and visualization tools facilitate complex user specific bioinformatics analyses.
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Affiliation(s)
- Jordan Pischimarov
- Institute of Medical Microbiology, Justus-Liebig-University, Schubertstrasse 81, Giessen, D-35392, Germany
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Abstract
The genus Enterococcus includes some of the most important nosocomial multidrug-resistant organisms, and these pathogens usually affect patients who are debilitated by other, concurrent illnesses and undergoing prolonged hospitalization. This Review discusses the factors involved in the changing epidemiology of enterococcal infections, with an emphasis on Enterococcus faecium as an emergent and challenging nosocomial problem. The effects of antibiotics on the gut microbiota and on colonization with vancomycin-resistant enterococci are highlighted, including how enterococci benefit from the antibiotic-mediated eradication of gram-negative members of the gut microbiota. Analyses of enterococcal genomes indicate that there are certain genetic lineages, including an E. faecium clade of ancient origin, with the ability to succeed in the hospital environment, and the possible virulence determinants that are found in these genetic lineages are discussed. Finally, we review the most important mechanisms of resistance to the antibiotics that are used to treat vancomycin-resistant enterococci.
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Frank KL, Barnes AMT, Grindle SM, Manias DA, Schlievert PM, Dunny GM. Use of recombinase-based in vivo expression technology to characterize Enterococcus faecalis gene expression during infection identifies in vivo-expressed antisense RNAs and implicates the protease Eep in pathogenesis. Infect Immun 2012; 80:539-49. [PMID: 22144481 PMCID: PMC3264308 DOI: 10.1128/iai.05964-11] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 11/19/2011] [Indexed: 12/28/2022] Open
Abstract
Enterococcus faecalis is a member of the mammalian gastrointestinal microflora that has become a leading cause of nosocomial infections over the past several decades. E. faecalis must be able to adapt its physiology based on its surroundings in order to thrive in a mammalian host as both a commensal and a pathogen. We employed recombinase-based in vivo expression technology (RIVET) to identify promoters on the E. faecalis OG1RF chromosome that were specifically activated during the course of infection in a rabbit subdermal abscess model. The RIVET screen identified 249 putative in vivo-activated loci, over one-third of which are predicted to generate antisense transcripts. Three predicted antisense transcripts were detected in in vitro- and in vivo-grown cells, providing the first evidence of in vivo-expressed antisense RNAs in E. faecalis. Deletions in the in vivo-activated genes that encode glutamate 5-kinase (proB [EF0038]), the transcriptional regulator EbrA (ebrA [EF1809]), and the membrane metalloprotease Eep (eep [EF2380]) did not hinder biofilm formation in in vitro assays. In a rabbit model of endocarditis, the ΔebrA strain was fully virulent, the ΔproB strain was slightly attenuated, and the Δeep strain was severely attenuated. The Δeep virulence defect could be complemented by the expression of the wild-type gene in trans. Microscopic analysis of early Δeep biofilms revealed an abundance of small cellular aggregates that were not observed in wild-type biofilms. This work illustrates the use of a RIVET screen to provide information about the temporal activation of genes during infection, resulting in the identification and confirmation of a new virulence determinant in an important pathogen.
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Affiliation(s)
- Kristi L Frank
- Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota, USA.
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Genome-wide antisense transcription drives mRNA processing in bacteria. Proc Natl Acad Sci U S A 2011; 108:20172-7. [PMID: 22123973 DOI: 10.1073/pnas.1113521108] [Citation(s) in RCA: 196] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
RNA deep sequencing technologies are revealing unexpected levels of complexity in bacterial transcriptomes with the discovery of abundant noncoding RNAs, antisense RNAs, long 5' and 3' untranslated regions, and alternative operon structures. Here, by applying deep RNA sequencing to both the long and short RNA fractions (<50 nucleotides) obtained from the major human pathogen Staphylococcus aureus, we have detected a collection of short RNAs that is generated genome-wide through the digestion of overlapping sense/antisense transcripts by RNase III endoribonuclease. At least 75% of sense RNAs from annotated genes are subject to this mechanism of antisense processing. Removal of RNase III activity reduces the amount of short RNAs and is accompanied by the accumulation of discrete antisense transcripts. These results suggest the production of pervasive but hidden antisense transcription used to process sense transcripts by means of creating double-stranded substrates. This process of RNase III-mediated digestion of overlapping transcripts can be observed in several evolutionarily diverse Gram-positive bacteria and is capable of providing a unique genome-wide posttranscriptional mechanism to adjust mRNA levels.
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Progress in prokaryotic transcriptomics. Curr Opin Microbiol 2011; 14:579-86. [DOI: 10.1016/j.mib.2011.07.023] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 07/18/2011] [Accepted: 07/23/2011] [Indexed: 12/20/2022]
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Shioya K, Michaux C, Kuenne C, Hain T, Verneuil N, Budin-Verneuil A, Hartsch T, Hartke A, Giard JC. Genome-wide identification of small RNAs in the opportunistic pathogen Enterococcus faecalis V583. PLoS One 2011; 6:e23948. [PMID: 21912655 PMCID: PMC3166299 DOI: 10.1371/journal.pone.0023948] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2011] [Accepted: 07/28/2011] [Indexed: 01/29/2023] Open
Abstract
Small RNA molecules (sRNAs) are key mediators of virulence and stress inducible gene expressions in some pathogens. In this work we identify sRNAs in the gram positive opportunistic pathogen Enterococcus faecalis. We characterized 11 sRNAs by tiling microarray analysis, 5' and 3' RACE-PCR, and Northern blot analysis. Six sRNAs were specifically expressed at exponential phase, two sRNAs were observed at stationary phase, and three were detected during both phases. Searches of putative functions revealed that three of them (EFA0080_EFA0081 and EFB0062_EFB0063 on pTF1 and pTF2 plasmids, respectively, and EF0408_EF04092 located on the chromosome) are similar to antisense RNA involved in plasmid addiction modules. Moreover, EF1097_EF1098 shares strong homologies with tmRNA (bi-functional RNA acting as both a tRNA and an mRNA) and EF2205_EF2206 appears homologous to 4.5S RNA member of the Signal Recognition Particle (SRP) ribonucleoprotein complex. In addition, proteomic analysis of the ΔEF3314_EF3315 sRNA mutant suggests that it may be involved in the turnover of some abundant proteins. The expression patterns of these transcripts were evaluated by tiling array hybridizations performed with samples from cells grown under eleven different conditions some of which may be encountered during infection. Finally, distribution of these sRNAs among genome sequences of 54 E. faecalis strains was assessed. This is the first experimental genome-wide identification of sRNAs in E. faecalis and provides impetus to the understanding of gene regulation in this important human pathogen.
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Affiliation(s)
- Kouki Shioya
- Laboratoire de Microbiologie de l'Environnement, EA956-USC INRA 2017-IFR146 ICORE, University of Caen, Caen, France
| | - Charlotte Michaux
- Laboratoire de Microbiologie de l'Environnement, EA956-USC INRA 2017-IFR146 ICORE, University of Caen, Caen, France
| | - Carsten Kuenne
- Institute of Medical Microbiology, Justus-Liebig-University, Giessen, Germany
| | - Torsten Hain
- Institute of Medical Microbiology, Justus-Liebig-University, Giessen, Germany
| | - Nicolas Verneuil
- Laboratoire de Microbiologie de l'Environnement, EA956-USC INRA 2017-IFR146 ICORE, University of Caen, Caen, France
| | - Aurélie Budin-Verneuil
- Laboratoire de Microbiologie de l'Environnement, EA956-USC INRA 2017-IFR146 ICORE, University of Caen, Caen, France
| | | | - Axel Hartke
- Laboratoire de Microbiologie de l'Environnement, EA956-USC INRA 2017-IFR146 ICORE, University of Caen, Caen, France
| | - Jean-Christophe Giard
- Laboratoire de Microbiologie de l'Environnement, EA956-USC INRA 2017-IFR146 ICORE, University of Caen, Caen, France
- * E-mail:
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Fleuchot B, Gitton C, Guillot A, Vidic J, Nicolas P, Besset C, Fontaine L, Hols P, Leblond-Bourget N, Monnet V, Gardan R. Rgg proteins associated with internalized small hydrophobic peptides: a new quorum-sensing mechanism in streptococci. Mol Microbiol 2011; 80:1102-19. [PMID: 21435032 DOI: 10.1111/j.1365-2958.2011.07633.x] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
We identified a genetic context encoding a transcriptional regulator of the Rgg family and a small hydrophobic peptide (SHP) in nearly all streptococci and suggested that it may be involved in a new quorum-sensing mechanism, with SHP playing the role of a pheromone. Here, we provide further support for this hypothesis by constructing a phylogenetic tree of the Rgg and Rgg-like proteins from Gram-positive bacteria and by studying the shp/rgg1358 locus of Streptococcus thermophilus LMD-9. We identified the shp1358 gene as a target of Rgg1358, and used it to confirm the existence of the steps of a quorum-sensing mechanism including secretion, maturation and reimportation of the pheromone into the cell. We used surface plasmon resonance to demonstrate interaction between the pheromone and the regulatory protein and performed electrophoretic mobility shift assays to assess binding of the transcriptional regulator to the promoter regions of its target genes. The active form of the pheromone was identified by mass spectrometry. Our findings demonstrate that the shp/rgg1358 locus encodes two components of a novel quorum-sensing mechanism involving a transcriptional regulator of the Rgg family and a SHP pheromone that is detected and reimported into the cell by the Ami oligopeptide transporter.
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Affiliation(s)
- B Fleuchot
- INRA, UMR1319 MICALIS, F-78352 Jouy en Josas, France
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