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Hasan MK, Jeannine Brady L. Nucleic acid-binding KH domain proteins influence a spectrum of biological pathways including as part of membrane-localized complexes. J Struct Biol X 2024; 10:100106. [PMID: 39040530 PMCID: PMC11261784 DOI: 10.1016/j.yjsbx.2024.100106] [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: 02/23/2024] [Revised: 06/18/2024] [Accepted: 06/24/2024] [Indexed: 07/24/2024] Open
Abstract
K-Homology domain (KH domain) proteins bind single-stranded nucleic acids, influence protein-protein interactions of proteins that harbor them, and are found in all kingdoms of life. In concert with other functional protein domains KH domains contribute to a variety of critical biological activities, often within higher order machineries including membrane-localized protein complexes. Eukaryotic KH domain proteins are linked to developmental processes, morphogenesis, and growth regulation, and their aberrant expression is often associated with cancer. Prokaryotic KH domain proteins are involved in integral cellular activities including cell division and protein translocation. Eukaryotic and prokaryotic KH domains share structural features, but are differentiated based on their structural organizations. In this review, we explore the structure/function relationships of known examples of KH domain proteins, and highlight cases in which they function within or at membrane surfaces. We also summarize examples of KH domain proteins that influence bacterial virulence and pathogenesis. We conclude the article by discussing prospective research avenues that could be pursued to better investigate this largely understudied protein category.
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Affiliation(s)
- Md Kamrul Hasan
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - L. Jeannine Brady
- Department of Oral Biology, University of Florida, Gainesville, FL 32610, USA
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2
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Broglia L, Le Rhun A, Charpentier E. Methodologies for bacterial ribonuclease characterization using RNA-seq. FEMS Microbiol Rev 2023; 47:fuad049. [PMID: 37656885 PMCID: PMC10503654 DOI: 10.1093/femsre/fuad049] [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: 03/23/2023] [Revised: 08/06/2023] [Accepted: 08/23/2023] [Indexed: 09/03/2023] Open
Abstract
Bacteria adjust gene expression at the post-transcriptional level through an intricate network of small regulatory RNAs and RNA-binding proteins, including ribonucleases (RNases). RNases play an essential role in RNA metabolism, regulating RNA stability, decay, and activation. These enzymes exhibit species-specific effects on gene expression, bacterial physiology, and different strategies of target recognition. Recent advances in high-throughput RNA sequencing (RNA-seq) approaches have provided a better understanding of the roles and modes of action of bacterial RNases. Global studies aiming to identify direct targets of RNases have highlighted the diversity of RNase activity and RNA-based mechanisms of gene expression regulation. Here, we review recent RNA-seq approaches used to study bacterial RNases, with a focus on the methods for identifying direct RNase targets.
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Affiliation(s)
- Laura Broglia
- Max Planck Unit for the Science of Pathogens, D-10117 Berlin, Germany
- Center for Human Technologies, Istituto Italiano di Tecnologia, 16152 Genova, Italy
| | - Anaïs Le Rhun
- Max Planck Unit for the Science of Pathogens, D-10117 Berlin, Germany
- Univ. Bordeaux, CNRS, INSERM, ARNA, UMR 5320, U1212, F-33000 Bordeaux, France
| | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, D-10117 Berlin, Germany
- Institute for Biology, Humboldt University, D-10115 Berlin, Germany
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3
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Wang N, Li P, Cheng Y, Song H, Xu C. Stem-loop structures control mRNA processing of the cellulosomal cip-cel operon in Ruminiclostridium cellulolyticum. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:106. [PMID: 37386549 DOI: 10.1186/s13068-023-02357-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 06/11/2023] [Indexed: 07/01/2023]
Abstract
BACKGROUND Anaerobic, mesophilic, and cellulolytic Ruminiclostridium cellulolyticum produces an efficient cellulolytic extracellular complex named cellulosome, which consist of a non-catalytic multi-functional integrating subunit, organizing the various catalytic subunits into the complex. Main components of cellulosome were encoded by the cip-cel operon in R. cellulolyticum, and their stoichiometry is controlled by the mechanism of selective RNA processing and stabilization, which allows to confer each processed RNA portion from the cip-cel mRNA on different fates due to their stability and resolve the potential contradiction between the equimolar stoichiometry of transcripts with a within a transcription unit and the non-equimolar stoichiometry of subunits. RESULTS In this work, RNA processing events were found to occur at six intergenic regions (IRs) harboring stem-loop structures in cip-cel operon. These stem-loops not only stabilize processed transcripts at their both ends, but also act as cleavage signals specifically recognized by endoribonucleases. We further demonstrated that cleavage sites were often located downstream or 3' end of their associated stem-loops that could be classified into two types, with distinct GC-rich stems being required for RNA cleavage. However, the cleavage site in IR4 was found to be located upstream of the stem-loop, as determined by the bottom AT-pair region of this stem-loop, together with its upstream structure. Thus, our findings reveal the structural requirements for processing of cip-cel transcripts, which can be potentially used to control the stoichiometry of gene expression in an operon. CONCLUSIONS Our findings reveal that stem-loop structures acting as RNA cleavage signals not only can be recognized by endoribonucleases and determine the location of cleavage sites but also determine the stoichiometry of their flanking processed transcripts by controlling stability in cip-cel operon. These features represent a complexed regulation of cellulosome in the post-transcriptional level, which can be exploited for designing synthetic elements to control gene expression.
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Affiliation(s)
- Na Wang
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, 311300, Zhejiang, China
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Ping Li
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Ying Cheng
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006, Shanxi, China
| | - Houhui Song
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, 311300, Zhejiang, China.
| | - Chenggang Xu
- Key Laboratory of Applied Technology on Green-Eco-Healthy Animal Husbandry of Zhejiang Province, China-Australia Joint Laboratory for Animal Health Big Data Analytics, Zhejiang Provincial Engineering Research Center for Animal Health Diagnostics & Advanced Technology, Zhejiang International Science and Technology Cooperation Base for Veterinary Medicine and Health Management, College of Animal Science and Technology & College of Veterinary Medicine, Zhejiang A&F University, Hangzhou, 311300, Zhejiang, China.
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan, 030006, Shanxi, China.
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4
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Condinho M, Carvalho B, Cruz A, Pinto SN, Arraiano CM, Pobre V. The role of RNA regulators, quorum sensing and c-di-GMP in bacterial biofilm formation. FEBS Open Bio 2023; 13:975-991. [PMID: 35234364 PMCID: PMC10240345 DOI: 10.1002/2211-5463.13389] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 02/15/2022] [Accepted: 02/28/2022] [Indexed: 11/10/2022] Open
Abstract
Biofilms provide an ecological advantage against many environmental stressors, such as pH and temperature, making it the most common life-cycle stage for many bacteria. These protective characteristics make eradication of bacterial biofilms challenging. This is especially true in the health sector where biofilm formation on hospital or patient equipment, such as respirators, or catheters, can quickly become a source of anti-microbial resistant strains. Biofilms are complex structures encased in a self-produced polymeric matrix containing numerous components such as polysaccharides, proteins, signalling molecules, extracellular DNA and extracellular RNA. Biofilm formation is tightly controlled by several regulators, including quorum sensing (QS), cyclic diguanylate (c-di-GMP) and small non-coding RNAs (sRNAs). These three regulators in particular are fundamental in all stages of biofilm formation; in addition, their pathways overlap, and the significance of their role is strain-dependent. Currently, ribonucleases are also of interest for their potential role as biofilm regulators, and their relationships with QS, c-di-GMP and sRNAs have been investigated. This review article will focus on these four biofilm regulators (ribonucleases, QS, c-di-GMP and sRNAs) and the relationships between them.
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Affiliation(s)
- Manuel Condinho
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
| | - Beatriz Carvalho
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
| | - Adriana Cruz
- iBB‐Institute for Bioengineering and Biosciences (IBB)Instituto Superior TécnicoLisboaPortugal
- i4HB‐Institute for Health and BioeconomyInstituto Superior TécnicoLisboaPortugal
| | - Sandra N. Pinto
- iBB‐Institute for Bioengineering and Biosciences (IBB)Instituto Superior TécnicoLisboaPortugal
- i4HB‐Institute for Health and BioeconomyInstituto Superior TécnicoLisboaPortugal
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
| | - Vânia Pobre
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaOeirasPortugal
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5
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Obana N. [Study on biofilm formation and heterogeneity in Clostridium perfringens]. Nihon Saikingaku Zasshi 2023; 78:159-165. [PMID: 37690815 DOI: 10.3412/jsb.78.159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Many bacteria form biofilms and survive in the actual environment. Biofilms are not only a major form of bacteria but are also involved in tolerance to environmental stresses and antibiotics, suggesting the association with bacterial pathogenesis. Cells within biofilms display phenotypic heterogeneity; thus, even bacteria, unicellular organisms, can functionally differentiate and show multicellular behavior. Therefore, it is necessary to understand bacteria as a population to control their survival and pathogenesis in the actual environment. Previously, we found that Clostridium perfringens, an anaerobic pathogenic bacterium, form different structures in different temperatures and phenotypic heterogeneity on biofilm matrix gene expression within the biofilm. In this article, I summarize the results of our research on biofilms and their heterogeneity, the mechanisms of post-transcriptional gene expression regulation of virulence genes, and bacteria-host interactions mediated by extracellular membrane vesicles.
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Affiliation(s)
- Nozomu Obana
- Transborder Medical Research Center, Institute of Medicine, University of Tsukuba
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6
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Structural Insights into the Dimeric Form of Bacillus subtilis RNase Y Using NMR and AlphaFold. Biomolecules 2022; 12:biom12121798. [PMID: 36551226 PMCID: PMC9775385 DOI: 10.3390/biom12121798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/04/2022] Open
Abstract
RNase Y is a crucial component of genetic translation, acting as the key enzyme initiating mRNA decay in many Gram-positive bacteria. The N-terminal domain of Bacillus subtilis RNase Y (Nter-BsRNaseY) is thought to interact with various protein partners within a degradosome complex. Bioinformatics and biophysical analysis have previously shown that Nter-BsRNaseY, which is in equilibrium between a monomeric and a dimeric form, displays an elongated fold with a high content of α-helices. Using multidimensional heteronuclear NMR and AlphaFold models, here, we show that the Nter-BsRNaseY dimer is constituted of a long N-terminal parallel coiled-coil structure, linked by a turn to a C-terminal region composed of helices that display either a straight or bent conformation. The structural organization of the N-terminal domain is maintained within the AlphaFold model of the full-length RNase Y, with the turn allowing flexibility between the N- and C-terminal domains. The catalytic domain is globular, with two helices linking the KH and HD modules, followed by the C-terminal region. This latter region, with no function assigned up to now, is most likely involved in the dimerization of B. subtilis RNase Y together with the N-terminal coiled-coil structure.
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7
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Cruz A, Condinho M, Carvalho B, Arraiano CM, Pobre V, Pinto SN. The Two Weapons against Bacterial Biofilms: Detection and Treatment. Antibiotics (Basel) 2021; 10:1482. [PMID: 34943694 PMCID: PMC8698905 DOI: 10.3390/antibiotics10121482] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 12/12/2022] Open
Abstract
Bacterial biofilms are defined as complex aggregates of bacteria that grow attached to surfaces or are associated with interfaces. Bacteria within biofilms are embedded in a self-produced extracellular matrix made of polysaccharides, nucleic acids, and proteins. It is recognized that bacterial biofilms are responsible for the majority of microbial infections that occur in the human body, and that biofilm-related infections are extremely difficult to treat. This is related with the fact that microbial cells in biofilms exhibit increased resistance levels to antibiotics in comparison with planktonic (free-floating) cells. In the last years, the introduction into the market of novel compounds that can overcome the resistance to antimicrobial agents associated with biofilm infection has slowed down. If this situation is not altered, millions of lives are at risk, and this will also strongly affect the world economy. As such, research into the identification and eradication of biofilms is important for the future of human health. In this sense, this article provides an overview of techniques developed to detect and imaging biofilms as well as recent strategies that can be applied to treat biofilms during the several biofilm formation steps.
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Affiliation(s)
- Adriana Cruz
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
- i4HB—Institute for Health and Bioeconomy, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Manuel Condinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; (M.C.); (B.C.); (C.M.A.)
| | - Beatriz Carvalho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; (M.C.); (B.C.); (C.M.A.)
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; (M.C.); (B.C.); (C.M.A.)
| | - Vânia Pobre
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal; (M.C.); (B.C.); (C.M.A.)
| | - Sandra N. Pinto
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal;
- i4HB—Institute for Health and Bioeconomy, Instituto Superior Técnico, University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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8
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Abstract
RNases perform indispensable functions in regulating gene expression in many bacterial pathogens by processing and/or degrading RNAs. Despite the pivotal role of RNases in regulating bacterial virulence factors, the functions of RNases have not yet been studied in the major human respiratory pathogen Streptococcus pneumoniae (pneumococcus). Here, we sought to determine the impact of two conserved RNases, the endoribonuclease RNase Y and exoribonuclease polynucleotide phosphorylase (PNPase), on the physiology and virulence of S. pneumoniae serotype 2 strain D39. We report that RNase Y and PNPase are essential for pneumococcal pathogenesis, as both deletion mutants showed strong attenuation of virulence in murine models of invasive pneumonia. Genome-wide transcriptomic analysis revealed that the abundances of nearly 200 mRNA transcripts were significantly increased, whereas those of several pneumococcal small regulatory RNAs (sRNAs), including the Ccn (CiaR-controlled noncoding RNA) sRNAs, were altered in the Δrny mutant relative to the wild-type strain. Additionally, lack of RNase Y resulted in pleiotropic phenotypes that included defects in pneumococcal cell morphology and growth in vitro. In contrast, Δpnp mutants showed no growth defect in vitro but differentially expressed a total of 40 transcripts, including the tryptophan biosynthesis operon genes and numerous 5' cis-acting regulatory RNAs, a majority of which were previously shown to impact pneumococcal disease progression in mice using the serotype 4 strain TIGR4. Together, our data suggest that RNase Y exerts a global impact on pneumococcal physiology, while PNPase mediates virulence phenotypes, likely through sRNA regulation. IMPORTANCE Streptococcus pneumoniae is a notorious human pathogen that adapts to conditions in distinct host tissues and responds to host cell interactions by adjusting gene expression. RNases are key players that modulate gene expression by mediating the turnover of regulatory and protein-coding transcripts. Here, we characterized two highly conserved RNases, RNase Y and PNPase, and evaluated their impact on the S. pneumoniae transcriptome for the first time. We show that PNPase influences the levels of a narrow set of mRNAs but a large number of regulatory RNAs primarily implicated in virulence control, whereas RNase Y has a more sweeping effect on gene expression, altering levels of transcripts involved in diverse cellular processes, including cell division, metabolism, stress response, and virulence. This study further reveals that RNase Y regulates expression of genes governing competence by mediating the turnover of CiaR-controlled noncoding (Ccn) sRNAs.
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9
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Obana N, Nakamura K, Nomura N. Temperature-regulated heterogeneous extracellular matrix gene expression defines biofilm morphology in Clostridium perfringens. NPJ Biofilms Microbiomes 2020; 6:29. [PMID: 32737303 PMCID: PMC7395162 DOI: 10.1038/s41522-020-00139-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 07/10/2020] [Indexed: 02/06/2023] Open
Abstract
Cells in biofilms dynamically adapt to surrounding environmental conditions, which alters biofilm architecture. The obligate anaerobic pathogen Clostridium perfringens shows different biofilm structures in different temperatures. Here we find that the temperature-regulated production of extracellular polymeric substance (EPS) is necessary for morphological changes in biofilms. We identify BsaA proteins as an EPS matrix necessary for pellicle biofilm formation at lower temperature and find that extracellularly secreted BsaA protein forms filamentous polymers. We show that sipW-bsaA operon expression is bimodal, and the EPS-producing population size is increased at a lower temperature. This heterogeneous expression of the EPS gene requires a two-component system. We find that EPS-producing cells cover EPS-nonproducing cells attaching to the bottom surface. In the deletion mutant of pilA2, encoding a type IV pilin, the EPS gene expression is ON in the whole population. This heterogeneity is further regulated by the cleavage of the pilA2 mRNA by RNase Y, causing temperature-responsive EPS expression in biofilms. As temperature is an environmental cue, C. perfringens may modulate EPS expression to induce morphological changes in biofilm structure as a strategy for adapting to interhost and external environments.
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Affiliation(s)
- Nozomu Obana
- Transborder Medical Research Center, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan. .,Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.
| | - Kouji Nakamura
- Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.,Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
| | - Nobuhiko Nomura
- Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan.,Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8572, Japan
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10
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Soncini SR, Hartman AH, Gallagher TM, Camper GJ, Jensen RV, Melville SB. Changes in the expression of genes encoding type IV pili-associated proteins are seen when Clostridium perfringens is grown in liquid or on surfaces. BMC Genomics 2020; 21:45. [PMID: 31937237 PMCID: PMC6958937 DOI: 10.1186/s12864-020-6453-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 01/07/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Clostridium perfringens is a Gram-positive anaerobic pathogen that causes multiple diseases in humans and animals. C. perfringens lack flagella but have type IV pili (TFP) and can glide on agar surfaces. When C. perfringens bacteria are placed on surfaces, they become elongated, flexible and have TFP on their surface, traits not seen in liquid-grown cells. In addition, the main pilin in C. perfringens TFP, PilA2, undergoes differential post-translational modification when grown in liquid or on plates. To understand the mechanisms underlying these phenotypes, bacteria were grown in three types of liquid media and on agar plates with the same medium to compare gene expression using RNA-Seq. RESULTS Hundreds of genes were differentially expressed, including transcriptional regulatory protein-encoding genes and genes associated with TFP functions, which were higher on plates than in liquid. Transcript levels of TFP genes reflected the proportion of each protein predicted to reside in a TFP assembly complex. To measure differences in rates of translation, the Escherichia coli reporter gene gusA gene (encoding β-glucuronidase) was inserted into the chromosome downstream of TFP promoters and in-frame with the first gene of the operon. β-glucuronidase expression was then measured in cells grown in liquid or on plates. β-glucuronidase activity was proportional to mRNA levels in liquid-grown cells, but not plate-grown cells, suggesting significant levels of post-transcriptional regulation of these TFP-associated genes occurs when cells are grown on surfaces. CONCLUSIONS This study reveals insights into how a non-flagellated pathogenic rod-shaped bacterium senses and responds to growth on surfaces, including inducing transcriptional regulators and activating multiple post-transcriptional regulatory mechanisms associated with TFP functions.
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Affiliation(s)
- Samantha R Soncini
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.,Current address: UPMC Genome Center, Pittsburgh, PA, USA
| | - Andrea H Hartman
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Tara M Gallagher
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.,Current address: Department of Molecular Biology & Biochemistry, University of California, Irvine, USA
| | - Gary J Camper
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Roderick V Jensen
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Stephen B Melville
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA, 24061, USA.
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11
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Bacterial RNA Degradosomes: Molecular Machines under Tight Control. Trends Biochem Sci 2019; 45:42-57. [PMID: 31679841 DOI: 10.1016/j.tibs.2019.10.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/30/2019] [Accepted: 10/03/2019] [Indexed: 01/05/2023]
Abstract
Bacterial RNA degradosomes are multienzyme molecular machines that act as hubs for post-transcriptional regulation of gene expression. The ribonuclease activities of these complexes require tight regulation, as they are usually essential for cell survival while potentially destructive. Recent studies have unveiled a wide variety of regulatory mechanisms including autoregulation, post-translational modifications, and protein compartmentalization. Recently, the subcellular organization of bacterial RNA degradosomes was found to present similarities with eukaryotic messenger ribonucleoprotein (mRNP) granules, membraneless compartments that are also involved in mRNA and protein storage and/or mRNA degradation. In this review, we present the current knowledge on the composition and targets of RNA degradosomes, the most recent developments regarding the regulation of these machineries, and their similarities with the eukaryotic mRNP granules.
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12
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Bechhofer DH, Deutscher MP. Bacterial ribonucleases and their roles in RNA metabolism. Crit Rev Biochem Mol Biol 2019; 54:242-300. [PMID: 31464530 PMCID: PMC6776250 DOI: 10.1080/10409238.2019.1651816] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 07/22/2019] [Accepted: 07/31/2019] [Indexed: 12/16/2022]
Abstract
Ribonucleases (RNases) are mediators in most reactions of RNA metabolism. In recent years, there has been a surge of new information about RNases and the roles they play in cell physiology. In this review, a detailed description of bacterial RNases is presented, focusing primarily on those from Escherichia coli and Bacillus subtilis, the model Gram-negative and Gram-positive organisms, from which most of our current knowledge has been derived. Information from other organisms is also included, where relevant. In an extensive catalog of the known bacterial RNases, their structure, mechanism of action, physiological roles, genetics, and possible regulation are described. The RNase complement of E. coli and B. subtilis is compared, emphasizing the similarities, but especially the differences, between the two. Included are figures showing the three major RNA metabolic pathways in E. coli and B. subtilis and highlighting specific steps in each of the pathways catalyzed by the different RNases. This compilation of the currently available knowledge about bacterial RNases will be a useful tool for workers in the RNA field and for others interested in learning about this area.
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Affiliation(s)
- David H. Bechhofer
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Murray P. Deutscher
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA
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13
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Kuehne SA, Rood JI, Lyras D. Clostridial Genetics: Genetic Manipulation of the Pathogenic Clostridia. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0040-2018. [PMID: 31172914 PMCID: PMC11315012 DOI: 10.1128/microbiolspec.gpp3-0040-2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Indexed: 02/07/2023] Open
Abstract
The past 10 years have been revolutionary for clostridial genetics. The rise of next-generation sequencing led to the availability of annotated whole-genome sequences of the important pathogenic clostridia: Clostridium perfringens, Clostridioides (Clostridium) difficile, and Clostridium botulinum, but also Paeniclostridium (Clostridium) sordellii and Clostridium tetani. These sequences were a prerequisite for the development of functional, sophisticated genetic tools for the pathogenic clostridia. A breakthrough came in the early 2000s with the development of TargeTron-based technologies specific for the clostridia, such as ClosTron, an insertional gene inactivation tool. The following years saw a plethora of new technologies being developed, mostly for C. difficile, but also for other members of the genus, including C. perfringens. A range of tools is now available, allowing researchers to precisely delete genes, change single nucleotides in the genome, complement deletions, integrate novel DNA into genomes, or overexpress genes. There are tools for forward genetics, including an inducible transposon mutagenesis system for C. difficile. As the latest addition to the tool kit, clustered regularly interspaced short palindromic repeat (CRISPR)-Cas9 technologies have also been adopted for the construction of single and multiple gene deletions in C. difficile. This article summarizes the key genetic technologies available to manipulate, study, and understand the pathogenic clostridia.
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Affiliation(s)
- S A Kuehne
- School of Dentistry and Institute for Microbiology and Infection, University of Birmingham, Birmingham, UK
| | - J I Rood
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia 3800
| | - D Lyras
- Infection and Immunity Program, Monash Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia 3800
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14
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Chen Z, Raghavan R, Qi F, Merritt J, Kreth J. Genome-wide screening of potential RNase Y-processed mRNAs in the M49 serotype Streptococcus pyogenes NZ131. Microbiologyopen 2019; 8:e00671. [PMID: 29900693 PMCID: PMC6460267 DOI: 10.1002/mbo3.671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 05/07/2018] [Accepted: 05/15/2018] [Indexed: 01/28/2023] Open
Abstract
RNase Y is a major endoribonuclease in Group A streptococcus (GAS) and other Gram-positive bacteria. Our previous study showed that RNase Y was involved in mRNA degradation and processing in GAS. We hypothesized that mRNA processing regulated the expression of important GAS virulence factors via altering their mRNA stabilities and that RNase Y mediated at least some of the mRNA-processing events. The aims of this study were to (1) identify mRNAs that were processed by RNase Y and (2) confirm the mRNA-processing events. The transcriptomes of Streptococcus pyogenes NZ131 wild type and its RNase Y mutant (Δrny) were examined with RNA-seq. The data were further analyzed to define GAS operons. The mRNA stabilities of the wild type and Δrny at subgene level were determined with tiling array analysis. Operons displaying segmental stability in the wild type but not in the Δrny were predicted to be RNase Y processed. Overall 865 operons were defined and their boundaries predicted. Further analysis narrowed down 15 mRNAs potentially processed by RNase Y. A selection of four candidates including folC1 (folylpolyglutamate synthetase), prtF (fibronectin-binding protein), speG (streptococcal exotoxin G), ropB (transcriptional regulator of speB), and ypaA (riboflavin transporter) mRNAs was examined with Northern blot analysis. However, only folC1 was confirmed to be processed, but it is unlikely that RNase Y is responsible. We conclude that GAS use RNase Y to selectively process mRNA, but the overall impact is confined to selected virulence factors.
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Affiliation(s)
- Zhiyun Chen
- Department of Microbiology and ImmunologyUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahoma
| | - Rahul Raghavan
- Department of Biology and Center for Life in Extreme EnvironmentsPortland State UniversityPortlandOregon
| | - Fengxia Qi
- Department of Microbiology and ImmunologyUniversity of Oklahoma Health Sciences CenterOklahoma CityOklahoma
| | - Justin Merritt
- Department of Restorative DentistryOregon Health and Science UniversityPortlandOregon
- Department of Molecular Microbiology and ImmunologyOregon Health and Science UniversityPortlandOregon
| | - Jens Kreth
- Department of Restorative DentistryOregon Health and Science UniversityPortlandOregon
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15
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Abstract
RNases are key enzymes involved in RNA maturation and degradation. Although they play a crucial role in all domains of life, bacteria, archaea, and eukaryotes have evolved with their own sets of RNases and proteins modulating their activities. In bacteria, these enzymes allow modulation of gene expression to adapt to rapidly changing environments. Today, >20 RNases have been identified in both Escherichia coli and Bacillus subtilis, the paradigms of the Gram-negative and Gram-positive bacteria, respectively. However, only a handful of these enzymes are common to these two organisms and some of them are essential to only one. Moreover, although sets of RNases can be very similar in closely related bacteria such as the Firmicutes Staphylococcus aureus and B. subtilis, the relative importance of individual enzymes in posttranscriptional regulation in these organisms varies. In this review, we detail the role of the main RNases involved in RNA maturation and degradation in Gram-positive bacteria, with an emphasis on the roles of RNase J1, RNase III, and RNase Y. We also discuss how other proteins such as helicases can modulate the RNA-degradation activities of these enzymes.
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16
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Broglia L, Materne S, Lécrivain AL, Hahnke K, Le Rhun A, Charpentier E. RNase Y-mediated regulation of the streptococcal pyrogenic exotoxin B. RNA Biol 2018; 15:1336-1347. [PMID: 30290721 PMCID: PMC6284565 DOI: 10.1080/15476286.2018.1532253] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Endoribonuclease Y (RNase Y) is a crucial regulator of virulence in Gram-positive bacteria. In the human pathogen Streptococcus pyogenes, RNase Y is required for the expression of the major secreted virulence factor streptococcal pyrogenic exotoxin B (SpeB), but the mechanism involved in this regulation remains elusive. Here, we demonstrate that the 5′ untranslated region of speB mRNA is processed by several RNases including RNase Y. In particular, we identify two RNase Y cleavage sites located downstream of a guanosine (G) residue. To assess whether this nucleotide is required for RNase Y activity in vivo, we mutated it and demonstrate that the presence of this G residue is essential for the processing of the speB mRNA 5′ UTR by RNase Y. Although RNase Y directly targets and processes speB, we show that RNase Y-mediated regulation of speB expression occurs primarily at the transcriptional level and independently of the processing in the speB mRNA 5′ UTR. To conclude, we demonstrate for the first time that RNase Y processing of an mRNA target requires the presence of a G. We also provide new insights on the speB 5′ UTR and on the role of RNase Y in speB regulation.
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Affiliation(s)
- Laura Broglia
- a Max Planck Unit for the Science of Pathogens , Berlin , Germany.,b Department of Regulation in Infection Biology , Max Planck Institute for Infection Biology , Berlin , Germany.,c Institute for Biology , Humboldt University , Berlin , Germany.,d Department of Regulation in Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany
| | - Solange Materne
- a Max Planck Unit for the Science of Pathogens , Berlin , Germany.,b Department of Regulation in Infection Biology , Max Planck Institute for Infection Biology , Berlin , Germany
| | - Anne-Laure Lécrivain
- a Max Planck Unit for the Science of Pathogens , Berlin , Germany.,b Department of Regulation in Infection Biology , Max Planck Institute for Infection Biology , Berlin , Germany.,e The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology , Umeå University , Umeå , Sweden
| | - Karin Hahnke
- a Max Planck Unit for the Science of Pathogens , Berlin , Germany.,b Department of Regulation in Infection Biology , Max Planck Institute for Infection Biology , Berlin , Germany
| | - Anaïs Le Rhun
- a Max Planck Unit for the Science of Pathogens , Berlin , Germany.,b Department of Regulation in Infection Biology , Max Planck Institute for Infection Biology , Berlin , Germany.,d Department of Regulation in Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany.,e The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology , Umeå University , Umeå , Sweden
| | - Emmanuelle Charpentier
- a Max Planck Unit for the Science of Pathogens , Berlin , Germany.,b Department of Regulation in Infection Biology , Max Planck Institute for Infection Biology , Berlin , Germany.,c Institute for Biology , Humboldt University , Berlin , Germany.,d Department of Regulation in Infection Biology , Helmholtz Centre for Infection Research , Braunschweig , Germany.,e The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology , Umeå University , Umeå , Sweden
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17
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Adachi K, Ohtani K, Kawano M, Singh RP, Yousuf B, Sonomoto K, Shimizu T, Nakayama J. Metabolic dependent and independent pH-drop shuts down VirSR quorum sensing in Clostridium perfringens. J Biosci Bioeng 2018; 125:525-531. [PMID: 29373309 DOI: 10.1016/j.jbiosc.2017.12.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 12/20/2017] [Accepted: 12/20/2017] [Indexed: 12/20/2022]
Abstract
Clostridium perfringens produces various exotoxins and enzymes that cause food poisoning and gas gangrene. The genes involved in virulence are regulated by the agr-like quorum sensing (QS) system, which consists of a QS signal synthesis system and a VirSR two-component regulatory system (VirSR TCS) which is a global regulatory system composed of signal sensor kinase (VirS) and response regulator (VirR). We found that the perfringolysin O gene (pfoA) was transiently expressed during mid-log phase of bacterial growth; its expression was rapidly shut down thereafter, suggesting the existence of a self-quorum quenching (sQQ) system. The sQQ system was induced by the addition of stationary phase culture supernatant (SPCS). Activity of the sQQ system was heat stable, and was present following filtration through the ultrafiltration membrane, suggesting that small molecules acted as sQQ agents. In addition, sQQ was also induced by pure acetic and butyric acids at concentrations equivalent to those in the stationary phase culture, suggesting that organic acids produced by C. perfringens were involved in sQQ. In pH-controlled batch culture, sQQ was greatly diminished; expression level of pfoA extended to late-log growth phase, and was eventually increased by one order of magnitude. Furthermore, hydrochloric acid induced sQQ at the same pH as was used in organic acids. SPCS also suppressed the expression of genes regulated by VirSR TCS. Overall, the expression of virulence factors of C. perfringens was downregulated by the sQQ system, which was mediated by primary acidic metabolites and acidic environments. This suggested the possibility of pH-controlled anti-virulence strategies.
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Affiliation(s)
- Keika Adachi
- Laboratory of Microbial Technology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Kaori Ohtani
- Department of Bacteriology, Graduate School of Medical Science, University of Kanazawa, 13-1 Takaramachi, Kanazawa, Ishikawa 920-8203, Japan; Miyarisan Pharmaceutical Co. Ltd., 1-10-3 Kaminakazato, Kita-ku, Tokyo 114-0016, Japan
| | - Michio Kawano
- Laboratory of Microbial Technology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Ravindra Pal Singh
- Laboratory of Microbial Technology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Basit Yousuf
- Laboratory of Microbial Technology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Kenji Sonomoto
- Laboratory of Microbial Technology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan
| | - Tohru Shimizu
- Department of Bacteriology, Graduate School of Medical Science, University of Kanazawa, 13-1 Takaramachi, Kanazawa, Ishikawa 920-8203, Japan
| | - Jiro Nakayama
- Laboratory of Microbial Technology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka 812-8581, Japan.
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18
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Marincola G, Wolz C. Downstream element determines RNase Y cleavage of the saePQRS operon in Staphylococcus aureus. Nucleic Acids Res 2017; 45:5980-5994. [PMID: 28453818 PMCID: PMC5449607 DOI: 10.1093/nar/gkx296] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Accepted: 04/12/2017] [Indexed: 12/19/2022] Open
Abstract
In gram-positive bacteria, RNase J1, RNase J2 and RNase Y are thought to be major contributors to mRNA degradation and maturation. In Staphylococcus aureus, RNase Y activity is restricted to regulating the mRNA decay of only certain transcripts. Here the saePQRS operon was used as a model to analyze RNase Y specificity in living cells. A RNase Y cleavage site is located in an intergenic region between saeP and saeQ. This cleavage resulted in rapid degradation of the upstream fragment and stabilization of the downstream fragment. Thereby, the expression ratio of the different components of the operon was shifted towards saeRS, emphasizing the regulatory role of RNase Y activity. To assess cleavage specificity different regions surrounding the sae CS were cloned upstream of truncated gfp, and processing was analyzed in vivo using probes up- and downstream of CS. RNase Y cleavage was not determined by the cleavage site sequence. Instead a 24-bp double-stranded recognition structure was identified that was required to initiate cleavage 6 nt upstream. The results indicate that RNase Y activity is determined by secondary structure recognition determinants, which guide cleavage from a distance.
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Affiliation(s)
- Gabriella Marincola
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
| | - Christiane Wolz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen 72076, Germany
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