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Bouillet S, Bauer TS, Gottesman S. RpoS and the bacterial general stress response. Microbiol Mol Biol Rev 2024; 88:e0015122. [PMID: 38411096 PMCID: PMC10966952 DOI: 10.1128/mmbr.00151-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/28/2024] Open
Abstract
SUMMARYThe general stress response (GSR) is a widespread strategy developed by bacteria to adapt and respond to their changing environments. The GSR is induced by one or multiple simultaneous stresses, as well as during entry into stationary phase and leads to a global response that protects cells against multiple stresses. The alternative sigma factor RpoS is the central GSR regulator in E. coli and conserved in most γ-proteobacteria. In E. coli, RpoS is induced under conditions of nutrient deprivation and other stresses, primarily via the activation of RpoS translation and inhibition of RpoS proteolysis. This review includes recent advances in our understanding of how stresses lead to RpoS induction and a summary of the recent studies attempting to define RpoS-dependent genes and pathways.
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Affiliation(s)
- Sophie Bouillet
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, Bethesda, Maryland, USA
| | - Taran S. Bauer
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, Bethesda, Maryland, USA
| | - Susan Gottesman
- Laboratory of Molecular Biology, Center for Cancer Research, NCI, Bethesda, Maryland, USA
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2
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Luo X, Majdalani N. Directed Screening for sRNA Targets in E. coli Using a Plasmid Library. Methods Mol Biol 2024; 2741:291-306. [PMID: 38217660 DOI: 10.1007/978-1-0716-3565-0_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
A large number of bacterial small regulatory RNAs (sRNAs) modulate gene expression by base pairing to a target mRNA, affecting its translation or stability. This posttranscriptional regulation has been shown to be essential and critical for bacterial physiology. One of the challenges of studying sRNA signaling is identifying the sRNA regulators of specific genes. Here, we describe a protocol for making an sRNA expression library and using this library to screen for sRNA regulators of genes of interest in E. coli. This library can be easily expanded and adapted to use in other bacteria.
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Affiliation(s)
- Xing Luo
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, MD, USA.
| | - Nadim Majdalani
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, MD, USA
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3
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Turbant F, Esnouf E, Rosaz F, Wien F, Węgrzyn G, Chauvet H, Arluison V. Role of the Bacterial Amyloid-like Hfq in Fluoroquinolone Fluxes. Microorganisms 2023; 12:53. [PMID: 38257880 PMCID: PMC10819720 DOI: 10.3390/microorganisms12010053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 12/22/2023] [Accepted: 12/26/2023] [Indexed: 01/24/2024] Open
Abstract
Due to their two-cell membranes, Gram-negative bacteria are particularly resistant to antibiotics. Recent investigations aimed at exploring new target proteins involved in Gram-negative bacteria adaptation helped to identify environmental changes encountered during infection. One of the most promising approaches in finding novel targets for antibacterial drugs consists of blocking noncoding RNA-based regulation using the protein cofactor, Hfq. Although Hfq is important in many bacterial pathogens, its involvement in antibiotics response is still unclear. Indeed, Hfq may mediate drug resistance by regulating the major efflux system in Escherichia coli, but it could also play a role in the influx of antibiotics. Here, using an imaging approach, we addressed this problem quantitatively at the single-cell level. More precisely, we analyzed how Hfq affects the dynamic influx and efflux of ciprofloxacin, an antibiotic from the group of fluoroquinolones that is used to treat bacterial infections. Our results indicated that the absence of either whole Hfq or its C-terminal domain resulted in a more effective accumulation of ciprofloxacin, irrespective of the presence of the functional AcrAB-TolC efflux pump. However, overproduction of the MicF small regulatory RNA, which reduces the efficiency of expression of the ompF gene (coding for a porin involved in antibiotics influx) in a Hfq-dependent manner, resulted in impaired accumulation of ciprofloxacin. These results led us to propose potential mechanisms of action of Hfq in the regulation of fluoroquinolone fluxes across the E. coli envelope.
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Affiliation(s)
- Florian Turbant
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France; (F.T.); (F.W.); (H.C.)
- Laboratoire Léon Brillouin LLB, UMR12 CEA CNRS, CEA Saclay, 91191 Gif-sur-Yvette, France; (E.E.); (F.R.)
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Emeline Esnouf
- Laboratoire Léon Brillouin LLB, UMR12 CEA CNRS, CEA Saclay, 91191 Gif-sur-Yvette, France; (E.E.); (F.R.)
| | - Francois Rosaz
- Laboratoire Léon Brillouin LLB, UMR12 CEA CNRS, CEA Saclay, 91191 Gif-sur-Yvette, France; (E.E.); (F.R.)
| | - Frank Wien
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France; (F.T.); (F.W.); (H.C.)
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, Faculty of Biology, University of Gdansk, Wita Stwosza 59, 80-308 Gdansk, Poland;
| | - Hugo Chauvet
- Synchrotron SOLEIL, L’Orme des Merisiers, Saint Aubin BP48, 91192 Gif-sur-Yvette, France; (F.T.); (F.W.); (H.C.)
| | - Véronique Arluison
- Laboratoire Léon Brillouin LLB, UMR12 CEA CNRS, CEA Saclay, 91191 Gif-sur-Yvette, France; (E.E.); (F.R.)
- UFR SDV, Université Paris Cité, 75013 Paris, France
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4
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Wu R, Barnes S, Dahlin H, Khamrui S, Ingle S, Xiang Y, Shi Y, Bechhofer D, Lazarus M. Structural insights into RNA cleavage by a novel family of bacterial RNases. RESEARCH SQUARE 2023:rs.3.rs-3788707. [PMID: 38234822 PMCID: PMC10793500 DOI: 10.21203/rs.3.rs-3788707/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Processing of RNA is a key regulatory mechanism for all living systems. We recently discovered a novel family of endoribonucleases that is conserved across all bacteria. Here, using crystallography, cryo-EM microscopy, biochemical, biophysical, and mass spectrometry techniques, we are able to shed light on a novel RNA cleavage mechanism in bacteria. We show that YicC, the prototypical member of this family, forms a hexameric channel that closes down on a 26-mer RNA substrate, and find that it cleaves across an RNA hairpin to generate several short fragments.
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Affiliation(s)
- Ruoxi Wu
- Icahn School of Medicine at Mount Sinai
| | | | | | | | | | | | - Yi Shi
- Icahn School of Medicine at Mount Sinai
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5
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Goel N, Srivastav S, Patel A, Shirsath A, Panda TR, Patra M, Feist AM, Anand A. TCA cycle tailoring facilitates optimal growth of proton-pumping NADH dehydrogenase-dependent Escherichia coli. Microbiol Spectr 2023; 11:e0222523. [PMID: 37855642 PMCID: PMC10715208 DOI: 10.1128/spectrum.02225-23] [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: 05/26/2023] [Accepted: 09/12/2023] [Indexed: 10/20/2023] Open
Abstract
IMPORTANCE Energy generation pathways are a potential avenue for the development of novel antibiotics. However, bacteria possess remarkable resilience due to the compensatory pathways, which presents a challenge in this direction. NADH, the primary reducing equivalent, can transfer electrons to two distinct types of NADH dehydrogenases. Type I NADH dehydrogenase is an enzyme complex comprising multiple subunits and can generate proton motive force (PMF). Type II NADH dehydrogenase does not pump protons but plays a crucial role in maintaining the turnover of NAD+. To study the adaptive rewiring of energy metabolism, we evolved an Escherichia coli mutant lacking type II NADH dehydrogenase. We discovered that by modifying the flux through the tricarboxylic acid (TCA) cycle, E. coli could mitigate the growth impairment observed in the absence of type II NADH dehydrogenase. This research provides valuable insights into the intricate mechanisms employed by bacteria to compensate for disruptions in energy metabolism.
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Affiliation(s)
- Nikita Goel
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Stuti Srivastav
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Arjun Patel
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
| | - Akshay Shirsath
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Tushar Ranjan Panda
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Malay Patra
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
| | - Adam M. Feist
- Department of Bioengineering, University of California, San Diego, La Jolla, California, USA
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kemitorvet, Kongens, Lyngby, Denmark
| | - Amitesh Anand
- Department of Biological Sciences, Tata Institute of Fundamental Research, Mumbai, Maharashtra, India
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6
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Luo X, Zhang A, Tai CH, Chen J, Majdalani N, Storz G, Gottesman S. An acetyltranferase moonlights as a regulator of the RNA binding repertoire of the RNA chaperone Hfq in Escherichia coli. Proc Natl Acad Sci U S A 2023; 120:e2311509120. [PMID: 38011569 PMCID: PMC10710024 DOI: 10.1073/pnas.2311509120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Accepted: 10/23/2023] [Indexed: 11/29/2023] Open
Abstract
Bacterial small RNAs (sRNAs) regulate gene expression by base-pairing with their target mRNAs. In Escherichia coli and many other bacteria, this process is dependent on the RNA chaperone Hfq, a mediator for sRNA-mRNA annealing. YhbS (renamed here as HqbA), a putative Gcn5-related N-acetyltransferase (GNAT), was previously identified as a silencer of sRNA signaling in a genomic library screen. Here, we studied how HqbA regulates sRNA signaling and investigated its physiological roles in modulating Hfq activity. Using fluorescent reporter assays, we found that HqbA overproduction suppressed all tested Hfq-dependent sRNA signaling. Direct interaction between HqbA and Hfq was demonstrated both in vivo and in vitro, and mutants that blocked the interaction interfered with HqbA suppression of Hfq. However, an acetylation-deficient HqbA mutant still disrupted sRNA signaling, and HqbA interacted with Hfq at a site far from the active site. This suggests that HqbA may be bifunctional, with separate roles for regulating via Hfq interaction and for acetylation of undefined substrates. Gel shift assays revealed that HqbA strongly reduced the interaction between the Hfq distal face and low-affinity RNAs but not high-affinity RNAs. Comparative RNA immunoprecipitation of Hfq and sequencing showed enrichment of two tRNA precursors, metZWV and proM, by Hfq in mutants that lost the HqbA-Hfq interaction. Our results suggest that HqbA provides a level of quality control for Hfq by competing with low-affinity RNA binders.
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Affiliation(s)
- Xing Luo
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD20892
| | - Aixia Zhang
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD20892-4417
| | - Chin-Hsien Tai
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD20892
| | - Jiandong Chen
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD20892
| | - Nadim Majdalani
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD20892
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD20892-4417
| | - Susan Gottesman
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, Bethesda, MD20892
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Ruddell B, Hassall A, Moss WN, Sahin O, Plummer PJ, Zhang Q, Kreuder AJ. Direct interaction of small non-coding RNAs CjNC140 and CjNC110 optimizes expression of key pathogenic phenotypes of Campylobacter jejuni. mBio 2023; 14:e0083323. [PMID: 37409826 PMCID: PMC10470494 DOI: 10.1128/mbio.00833-23] [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: 04/13/2023] [Accepted: 04/18/2023] [Indexed: 07/07/2023] Open
Abstract
Small non-coding RNAs (sRNAs) are important players in modulating gene expression in bacterial pathogens, but their functions are largely undetermined in Campylobacter jejuni, an important cause of foodborne gastroenteritis in humans. In this study, we elucidated the functions of sRNA CjNC140 and its interaction with CjNC110, a previously characterized sRNA involved in the regulation of several virulence phenotypes of C. jejuni. Inactivation of CjNC140 increased motility, autoagglutination, L-methionine concentration, autoinducer-2 production, hydrogen peroxide resistance, and early chicken colonization, indicating a primarily inhibitory role of CjNC140 for these phenotypes. Apart from motility, all these effects directly contrasted the previously demonstrated positive regulation by CjNC110, suggesting that CjNC110 and CjNC140 operate in an opposite manner to modulate physiologic processes in C. jejuni. RNAseq and northern blotting further demonstrated that expression of CjNC140 increased in the absence of CjNC110, while expression of CjNC110 decreased in the absence of CjNC140, suggesting a possibility of their direct interaction. Indeed, electrophoretic mobility shift assay demonstrated a direct binding between the two sRNAs via GA- (CjNC110) and CU- (CjNC140) rich stem-loops. Additionally, RNAseq and follow-up experiments identified that CjNC140 positively regulates p19, which encodes a key iron uptake transporter in Campylobacter. Furthermore, computational analysis revealed both CjNC140 and CjNC110 are highly conserved in C. jejuni, and the predicted secondary structures support CjNC140 as a functional homolog of the iron regulatory sRNA, RyhB. These findings establish CjNC140 and CjNC110 as a key checks-and- balances mechanism in maintaining homeostasis of gene expression and optimizing phenotypes critical for C. jejuni pathobiology. IMPORTANCE Gene regulation is critical to all aspects of pathogenesis of bacterial disease, and small non-coding RNAs (sRNAs) represent a new frontier in gene regulation of bacteria. In Campylobacter jejuni, the role of sRNAs remains largely unexplored. Here, we investigate the role of two highly conserved sRNAs, CjNC110 and CjNC140, and demonstrate that CjNC140 displays a primarily inhibitory role in contrast to a primarily activating role for CjNC110 for several key virulence-associated phenotypes. Our results also revealed that the sRNA regulatory pathway is intertwined with the iron uptake system, another virulence mechanism critical for in vivo colonization. These findings open a new direction for understanding C. jejuni pathobiology and identify potential targets for intervention for this major foodborne pathogen.
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Affiliation(s)
- Brandon Ruddell
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
- National Institute of Antimicrobial Resistance Research and Education (NIAMRRE), Iowa State University Research Park, Ames, Iowa, USA
| | - Alan Hassall
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Walter N. Moss
- The Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Orhan Sahin
- National Institute of Antimicrobial Resistance Research and Education (NIAMRRE), Iowa State University Research Park, Ames, Iowa, USA
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Paul J. Plummer
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
- National Institute of Antimicrobial Resistance Research and Education (NIAMRRE), Iowa State University Research Park, Ames, Iowa, USA
- Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
| | - Qijing Zhang
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
- National Institute of Antimicrobial Resistance Research and Education (NIAMRRE), Iowa State University Research Park, Ames, Iowa, USA
| | - Amanda J. Kreuder
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, USA
- National Institute of Antimicrobial Resistance Research and Education (NIAMRRE), Iowa State University Research Park, Ames, Iowa, USA
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8
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Arias-Cartin R, Kazemzadeh Ferizhendi K, Séchet E, Pelosi L, Loeuillet C, Pierrel F, Barras F, Bouveret E. Role of the Escherichia coli ubiquinone-synthesizing UbiUVT pathway in adaptation to changing respiratory conditions. mBio 2023; 14:e0329822. [PMID: 37283518 PMCID: PMC10470549 DOI: 10.1128/mbio.03298-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 04/12/2023] [Indexed: 06/08/2023] Open
Abstract
Isoprenoid quinones are essential for cellular physiology. They act as electron and proton shuttles in respiratory chains and various biological processes. Escherichia coli and many α-, β-, and γ-proteobacteria possess two types of isoprenoid quinones: ubiquinone (UQ) is mainly used under aerobiosis, while demethylmenaquinones (DMK) are mostly used under anaerobiosis. Yet, we recently established the existence of an anaerobic O2-independent UQ biosynthesis pathway controlled by ubiT, ubiU, and ubiV genes. Here, we characterize the regulation of ubiTUV genes in E. coli. We show that the three genes are transcribed as two divergent operons that are both under the control of the O2-sensing Fnr transcriptional regulator. Phenotypic analyses using a menA mutant devoid of DMK revealed that UbiUV-dependent UQ synthesis is essential for nitrate respiration and uracil biosynthesis under anaerobiosis, while it contributes, though modestly, to bacterial multiplication in the mouse gut. Moreover, we showed by genetic study and 18O2 labeling that UbiUV contributes to the hydroxylation of ubiquinone precursors through a unique O2-independent process. Last, we report the crucial role of ubiT in allowing E. coli to shift efficiently from anaerobic to aerobic conditions. Overall, this study uncovers a new facet of the strategy used by E. coli to adjust its metabolism on changing O2 levels and respiratory conditions. This work links respiratory mechanisms to phenotypic adaptation, a major driver in the capacity of E. coli to multiply in gut microbiota and of facultative anaerobic pathogens to multiply in their host. IMPORTANCE Enterobacteria multiplication in the gastrointestinal tract is linked to microaerobic respiration and associated with various inflammatory bowel diseases. Our study focuses on the biosynthesis of ubiquinone, a key player in respiratory chains, under anaerobiosis. The importance of this study stems from the fact that UQ usage was for long considered to be restricted to aerobic conditions. Here we investigated the molecular mechanism allowing UQ synthesis in the absence of O2 and searched for the anaerobic processes that UQ is fueling in such conditions. We found that UQ biosynthesis involves anaerobic hydroxylases, that is, enzymes able to insert an O atom in the absence of O2. We also found that anaerobically synthesized UQ can be used for respiration on nitrate and the synthesis of pyrimidine. Our findings are likely to be applicable to most facultative anaerobes, which count many pathogens (Salmonella, Shigella, and Vibrio) and will help in unraveling microbiota dynamics.
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Affiliation(s)
- Rodrigo Arias-Cartin
- Département de Microbiologie, Institut Pasteur, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, Paris, France
| | | | - Emmanuel Séchet
- Département de Microbiologie, Institut Pasteur, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, Paris, France
| | - Ludovic Pelosi
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Corinne Loeuillet
- Univ. Grenoble Alpes, INSERM U1209, CNRS UMR 5309, Institute for Advanced Biosciences, Team Genetics Epigenetics and Therapies of Infertility, Grenoble, France
| | - Fabien Pierrel
- Univ. Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble, France
| | - Frédéric Barras
- Département de Microbiologie, Institut Pasteur, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, Paris, France
| | - Emmanuelle Bouveret
- Département de Microbiologie, Institut Pasteur, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, Paris, France
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Huang L, Tam KS, Xie W. Structural and Biochemical Studies of the Novel Hexameric Endoribonuclease YicC. ACS Chem Biol 2023; 18:1738-1747. [PMID: 37535940 DOI: 10.1021/acschembio.3c00091] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/05/2023]
Abstract
The decay of mRNA is an essential process to bacteria. The newly identified E. coli protein YicC is a founding member of the UPF0701 family, and biochemical studies indicated that it is an RNase involved in mRNA degradation. However, its biochemical properties and catalytic mechanism are poorly understood. Here, we report the crystal structure of YicC, which shows an extended shape consisting of modular domains. While the backbone trace of the monomer forms a unique, nearly closed loop, the three monomers present in the asymmetric unit make a "shoulder-by-shoulder" trimer. In vitro RNA cleavage assays indicated that this endoribonuclease mainly recognizes the consensus GUG motif, with a preference for an extended CGUG sequence. Additionally, the active enzyme exists as a hexamer in solution and assumes a funnel shape. Structural analysis indicated that the hexamer interface is mainly formed by the hexamerization domain consisting of D71-D124 and that the disruption of the oligomeric form greatly diminished the enzymatic activity. By studying the surface charge potential and the sequence conservation, we identified a series of residues that play critical functional roles, which helps to reveal the catalytic mechanism of this divalent metal-ion-dependent RNase. Last but not least, we discovered that the catalytic domain of YicC did not share similarity with any known nuclease fold, suggesting that the enzyme adopts a novel fold to perform its catalysis and in vivo functions. In summary, our investigations into YicC provide an in-depth understanding of the functions of the UPF0701 protein family and the DUF1732 domain in general.
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Affiliation(s)
- Lin Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - King Sing Tam
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
| | - Wei Xie
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory for Biocontrol, School of Life Sciences, The Sun Yat-Sen University, Guangzhou, Guangdong 510006, People's Republic of China
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10
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Schilder A, Görke B. Role of the 5' end phosphorylation state for small RNA stability and target RNA regulation in bacteria. Nucleic Acids Res 2023; 51:5125-5143. [PMID: 36987877 PMCID: PMC10250213 DOI: 10.1093/nar/gkad226] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/28/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
In enteric bacteria, several small RNAs (sRNAs) including MicC employ endoribonuclease RNase E to stimulate target RNA decay. A current model proposes that interaction of the sRNA 5' monophosphate (5'P) with the N-terminal sensing pocket of RNase E allosterically activates cleavage of the base-paired target in the active site. In vivo evidence supporting this model is lacking. Here, we engineered a genetic tool allowing us to generate 5' monophosphorylated sRNAs of choice in a controllable manner in the cell. Four sRNAs were tested and none performed better in target destabilization when 5' monophosphorylated. MicC retains full activity even when RNase E is defective in 5'P sensing, whereas regulation is lost upon removal of its scaffolding domain. Interestingly, sRNAs MicC and RyhB that originate with a 5' triphosphate group are dramatically destabilized when 5' monophosphorylated, but stable when in 5' triphosphorylated form. In contrast, the processing-derived sRNAs CpxQ and SroC, which carry 5'P groups naturally, are highly stable. Thus, the 5' phosphorylation state determines stability of naturally triphosphorylated sRNAs, but plays no major role for target RNA destabilization in vivo. In contrast, the RNase E C-terminal half is crucial for MicC-mediated ompD decay, suggesting that interaction with Hfq is mandatory.
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Affiliation(s)
- Alexandra Schilder
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Boris Görke
- Department of Microbiology, Immunobiology and Genetics, Max Perutz Labs, University of Vienna, Vienna Biocenter (VBC), 1030 Vienna, Austria
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Deblais L, Ranjit S, Vrisman C, Antony L, Scaria J, Miller SA, Rajashekara G. Role of Stress-Induced Proteins RpoS and YicC in the Persistence of Salmonella enterica subsp. enterica Serotype Typhimurium in Tomato Plants. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2023; 36:109-118. [PMID: 36394339 DOI: 10.1094/mpmi-07-22-0152-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Understanding the functional role of bacterial genes in the persistence of Salmonella in plant organs can facilitate the development of agricultural practices to mitigate food safety risks associated with the consumption of fresh produce contaminated with Salmonella spp. Our study showed that Salmonella enterica subsp. enterica serotype Typhimurium (strain MDD14) persisted less in inoculated tomato plants than other Salmonella Typhimurium strains tested (JSG210, JSG626, JSG634, JSG637, JSG3444, and EV030415; P < 0.01). In-vitro assays performed in limited-nutrient conditions (growth rate, biofilm production, and motility) were inconclusive in explaining the in-planta phenotype observed with MDD14. Whole-genome sequencing combined with non-synonymous single nucleotide variations analysis was performed to identify genomic differences between MDD14 and the other Salmonella Typhimurium strains. The genome of MDD14 contained a truncated version (123 bp N-terminal) of yicC and a mutated version of rpoS (two non-synonymous substitutions, i.e., G66E and R82C), which are two stress-induced proteins involved in iron acquisition, environmental sensing, and cell envelope integrity. The rpoS and yicC genes were deleted in Salmonella Typhimurium JSG210 with the Lambda Red recombining system. Both mutants had limited persistence in tomato plant organs, similar to that of MDD14. In conclusion, we demonstrated that YicC and RpoS are involved in the persistence of Salmonella in tomato plants in greenhouse conditions and, thus, could represent potential targets to mitigate persistence of Salmonella spp. in planta. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Loïc Deblais
- Department of Animal Sciences, The Ohio State University, Wooster, OH, U.S.A
| | - Sochina Ranjit
- Department of Animal Sciences, The Ohio State University, Wooster, OH, U.S.A
| | - Claudio Vrisman
- Department of Plant Pathology, The Ohio State University, Wooster, OH, U.S.A
| | - Linto Antony
- Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD, U.S.A
| | - Joy Scaria
- Department of Veterinary and Biomedical Sciences, South Dakota State University, Brookings, SD, U.S.A
| | - Sally A Miller
- Department of Plant Pathology, The Ohio State University, Wooster, OH, U.S.A
| | - Gireesh Rajashekara
- Department of Animal Sciences, The Ohio State University, Wooster, OH, U.S.A
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12
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Hadjeras L, Bouvier M, Canal I, Poljak L, Morin-Ogier Q, Froment C, Burlet-Schlitz O, Hamouche L, Girbal L, Cocaign-Bousquet M, Carpousis AJ. Attachment of the RNA degradosome to the bacterial inner cytoplasmic membrane prevents wasteful degradation of rRNA in ribosome assembly intermediates. PLoS Biol 2023; 21:e3001942. [PMID: 36603027 PMCID: PMC9848016 DOI: 10.1371/journal.pbio.3001942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 01/18/2023] [Accepted: 12/01/2022] [Indexed: 01/06/2023] Open
Abstract
RNA processing and degradation shape the transcriptome by generating stable molecules that are necessary for translation (rRNA and tRNA) and by facilitating the turnover of mRNA, which is necessary for the posttranscriptional control of gene expression. In bacteria and the plant chloroplast, RNA degradosomes are multienzyme complexes that process and degrade RNA. In many bacterial species, the endoribonuclease RNase E is the central component of the RNA degradosome. RNase E-based RNA degradosomes are inner membrane proteins in a large family of gram-negative bacteria (β- and γ-Proteobacteria). Until now, the reason for membrane localization was not understood. Here, we show that a mutant strain of Escherichia coli, in which the RNA degradosome is localized to the interior of the cell, has high levels of 20S and 40S particles that are defective intermediates in ribosome assembly. These particles have aberrant protein composition and contain rRNA precursors that have been cleaved by RNase E. After RNase E cleavage, rRNA fragments are degraded to nucleotides by exoribonucleases. In vitro, rRNA in intact ribosomes is resistant to RNase E cleavage, whereas protein-free rRNA is readily degraded. We conclude that RNA degradosomes in the nucleoid of the mutant strain interfere with cotranscriptional ribosome assembly. We propose that membrane-attached RNA degradosomes in wild-type cells control the quality of ribosome assembly after intermediates are released from the nucleoid. That is, the compact structure of mature ribosomes protects rRNA against cleavage by RNase E. Turnover of a proportion of intermediates in ribosome assembly explains slow growth of the mutant strain. Competition between mRNA and rRNA degradation could be the cause of slower mRNA degradation in the mutant strain. We conclude that attachment of the RNA degradosome to the bacterial inner cytoplasmic membrane prevents wasteful degradation of rRNA precursors, thus explaining the reason for conservation of membrane-attached RNA degradosomes throughout the β- and γ-Proteobacteria.
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Affiliation(s)
- Lydia Hadjeras
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France
| | - Marie Bouvier
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France
| | - Isabelle Canal
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France
| | - Leonora Poljak
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France
| | | | - Carine Froment
- IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Infrastructure Nationale de Protéomique, ProFI, Toulouse, France
| | - Odile Burlet-Schlitz
- IPBS, Université de Toulouse, CNRS, UPS, Toulouse, France
- Infrastructure Nationale de Protéomique, ProFI, Toulouse, France
| | - Lina Hamouche
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France
| | - Laurence Girbal
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | | | - Agamemnon J. Carpousis
- LMGM, Université de Toulouse, CNRS, UPS, CBI, Toulouse, France
- TBI, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- * E-mail:
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13
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Zhu W, Wang Y, Lv L, Wang H, Shi W, Liu Z, Yang W, Zhu J, Lu H. SHTXTHHly, an extracellular secretion platform for the preparation of bioactive peptides and proteins in Escherichia coli. Microb Cell Fact 2022; 21:128. [PMID: 35761329 PMCID: PMC9235172 DOI: 10.1186/s12934-022-01856-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 06/14/2022] [Indexed: 11/13/2022] Open
Abstract
Background In previous work, we developed an E. coli extracellular secretion platform XTHHly based on the hemolysin A secretion system. It can produce bioactive peptides with simple purification procedures. However, the wider application of this platform is limited by poor secretion efficiency. Results In this study, we first discovered a positive correlation between the isoelectric point (pI) value of the target protein and the secretion level of the XTHHly system. Given the extremely high secretion level of S tag, we fused it at the N-terminus and created a novel SHTXTHHly system. The SHTXTHHly system significantly increased the secretion levels of antimicrobial peptides (PEW300, LL37, and Aurein 1.2) with full bioactivities, suggesting its excellent capacity for secretory production of bioactive peptides. Furthermore, RGDS, IL-15, and alcohol dehydrogenase were successfully secreted, and their bioactivities were largely maintained in the fusion proteins, indicating the potential applications of the novel system for the rapid determination of protein bioactivities. Finally, using the SHTXTHHly system, we produced the monomeric Fc, which showed a high affinity for Fcγ Receptor I and mediated the antibody-dependent immunological effects of immune cells, demonstrating its potential applications in immunotherapies. Conclusions The SHTXTHHly system described here facilitates the secretory production of various types of proteins in E. coli. In comparison to previously reported expression systems, our work enlightens an efficient and cost-effective way to evaluate the bioactivities of target proteins or produce them. Graphical abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12934-022-01856-8.
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Affiliation(s)
- Wen Zhu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Yang Wang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Liangyin Lv
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Hui Wang
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Wenqiang Shi
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Zexin Liu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Wei Yang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Jianwei Zhu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Huili Lu
- Engineering Research Center of Cell and Therapeutic Antibody, Ministry of Education, School of Pharmacy, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China.
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14
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Ingle S, Chhabra S, Chen J, Lazarus MB, Luo X, Bechhofer DH. Discovery and initial characterization of YloC, a novel endoribonuclease in Bacillus subtilis. RNA (NEW YORK, N.Y.) 2022; 28:227-238. [PMID: 34815358 PMCID: PMC8906540 DOI: 10.1261/rna.078962.121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
The Bacillus subtilis genome is predicted to encode numerous ribonucleases, including four 3' exoribonucleases that have been characterized to some extent. A strain containing gene knockouts of all four known 3' exoribonucleases is viable, suggesting that one or more additional RNases remain to be discovered. A protein extract from the quadruple RNase mutant strain was fractionated and RNase activity was followed, resulting in the identification of an enzyme activity catalyzed by the YloC protein. YloC is an endoribonuclease and is a member of the highly conserved "YicC family" of proteins that is widespread in bacteria. YloC is a metal-dependent enzyme that catalyzes the cleavage of single-stranded RNA, preferentially at U residues, and exists in an oligomeric form, most likely a hexamer. As such, YloC shares some characteristics with the SARS-CoV Nsp15 endoribonuclease. While the in vivo function of YloC in B. subtilis is yet to be determined, YloC was found to act similarly to YicC in an Escherichia coli in vivo assay that assesses decay of the small RNA, RyhB. Thus, YloC may play a role in small RNA regulation.
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Affiliation(s)
- Shakti Ingle
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Shivani Chhabra
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Jiandong Chen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Michael B Lazarus
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Xing Luo
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA
| | - David H Bechhofer
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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15
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Charbonnier M, González-Espinoza G, Kehl-Fie TE, Lalaouna D. Battle for Metals: Regulatory RNAs at the Front Line. Front Cell Infect Microbiol 2022; 12:952948. [PMID: 35865816 PMCID: PMC9294342 DOI: 10.3389/fcimb.2022.952948] [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: 05/25/2022] [Accepted: 06/09/2022] [Indexed: 11/13/2022] Open
Abstract
Metal such as iron, zinc, manganese, and nickel are essential elements for bacteria. These nutrients are required in crucial structural and catalytic roles in biological processes, including precursor biosynthesis, DNA replication, transcription, respiration, and oxidative stress responses. While essential, in excess these nutrients can also be toxic. The immune system leverages both of these facets, to limit bacterial proliferation and combat invaders. Metal binding immune proteins reduce the bioavailability of metals at the infection sites starving intruders, while immune cells intoxicate pathogens by providing metals in excess leading to enzyme mismetallation and/or reactive oxygen species generation. In this dynamic metal environment, maintaining metal homeostasis is a critical process that must be precisely coordinated. To achieve this, bacteria utilize diverse metal uptake and efflux systems controlled by metalloregulatory proteins. Recently, small regulatory RNAs (sRNAs) have been revealed to be critical post-transcriptional regulators, working in conjunction with transcription factors to promote rapid adaptation and to fine-tune bacterial adaptation to metal abundance. In this mini review, we discuss the expanding role for sRNAs in iron homeostasis, but also in orchestrating adaptation to the availability of other metals like manganese and nickel. Furthermore, we describe the sRNA-mediated interdependency between metal homeostasis and oxidative stress responses, and how regulatory networks controlled by sRNAs contribute to survival and virulence.
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Affiliation(s)
- Mathilde Charbonnier
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
| | | | - Thomas E Kehl-Fie
- Department of Microbiology, University of Illinois Urbana-Champaign, Urbana IL, United States.,Carl R. Woese Institute for Genomic Biology University of Illinois Urbana-Champaign, Urbana IL, United States
| | - David Lalaouna
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR9002, Strasbourg, France
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16
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Svensson SL, Sharma CM. RNase III-mediated processing of a trans-acting bacterial sRNA and its cis-encoded antagonist. eLife 2021; 10:69064. [PMID: 34843430 PMCID: PMC8687705 DOI: 10.7554/elife.69064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 11/28/2021] [Indexed: 12/27/2022] Open
Abstract
Bacterial small RNAs (sRNAs) are important post-transcriptional regulators in stress responses and virulence. They can be derived from an expanding list of genomic contexts, such as processing from parental transcripts by RNase E. The role of RNase III in sRNA biogenesis is less well understood despite its well-known roles in rRNA processing, RNA decay, and cleavage of sRNA-mRNA duplexes. Here, we show that RNase III processes a pair of cis-encoded sRNAs (CJnc190 and CJnc180) of the food-borne pathogen Campylobacter jejuni. While CJnc180 processing by RNase III requires CJnc190, RNase III processes CJnc190 independent of CJnc180 via cleavage of an intramolecular duplex. We also show that CJnc190 directly represses translation of the colonization factor PtmG by targeting a G-rich ribosome-binding site, and uncover that CJnc180 is a cis-acting antagonist of CJnc190, indirectly affecting ptmG regulation. Our study highlights a role for RNase III in sRNA biogenesis and adds cis-encoded RNAs to the expanding diversity of transcripts that can antagonize bacterial sRNAs.
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Affiliation(s)
- Sarah Lauren Svensson
- Department of Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
| | - Cynthia Mira Sharma
- Department of Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg, Würzburg, Germany
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