1
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Papenfort K, Storz G. Insights into bacterial metabolism from small RNAs. Cell Chem Biol 2024:S2451-9456(24)00304-0. [PMID: 39094580 DOI: 10.1016/j.chembiol.2024.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Revised: 05/08/2024] [Accepted: 07/11/2024] [Indexed: 08/04/2024]
Abstract
The study of small, regulatory RNAs (sRNA) that act by base-pairing with target RNAs in bacteria has been steadily advancing, particularly with the availability of more and more transcriptome and RNA-RNA interactome datasets. While the characterization of multiple sRNAs has helped to elucidate their mechanisms of action, these studies also are providing insights into protein function, control of metabolic flux, and connections between metabolic pathways as we will discuss here. In describing several examples of the metabolic insights gained, we will summarize the different types of base-pairing sRNAs including mRNA-derived sRNAs, sponge RNAs, RNA mimics, and dual-function RNAs as well as suggest how information about sRNAs could be exploited in the future.
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Affiliation(s)
- Kai Papenfort
- Friedrich Schiller University Jena, Institute of Microbiology, 07745 Jena, Germany; Microverse Cluster, Friedrich Schiller University Jena, 07743 Jena, Germany.
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892-4417, USA.
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2
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Gorelik MG, Yakhnin H, Pannuri A, Walker AC, Pourciau C, Czyz D, Romeo T, Babitzke P. Multitier regulation of the E. coli extreme acid stress response by CsrA. J Bacteriol 2024; 206:e0035423. [PMID: 38319100 PMCID: PMC11210196 DOI: 10.1128/jb.00354-23] [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: 10/26/2023] [Accepted: 01/15/2024] [Indexed: 02/07/2024] Open
Abstract
CsrA is an RNA-binding protein that regulates processes critical for growth and survival, including central carbon metabolism, motility, biofilm formation, stress responses, and expression of virulence factors in pathogens. Transcriptomics studies in Escherichia coli suggested that CsrA repressed genes involved in surviving extremely acidic conditions. Here, we examine the effects of disrupting CsrA-dependent regulation on the expression of genes and circuitry for acid stress survival and demonstrate CsrA-mediated repression at multiple levels. We show that this repression is critical for managing the trade-off between growth and survival; overexpression of acid stress genes caused by csrA disruption enhances survival under extreme acidity but is detrimental for growth under mildly acidic conditions. In vitro studies confirmed that CsrA binds specifically to mRNAs of structural and regulatory genes for acid stress survival, causing translational repression. We also found that translation of the top-tier acid stress regulator, evgA, is coupled to that of a small leader peptide, evgL, which is repressed by CsrA. Unlike dedicated acid stress response genes, csrA and its sRNA antagonists, csrB and csrC, did not exhibit a substantial response to acid shock. Furthermore, disruption of CsrA regulation of acid stress genes impacted host-microbe interactions in Caenorhabditis elegans, alleviating GABA deficiencies. This study expands the known regulon of CsrA to genes of the extreme acid stress response of E. coli and highlights a new facet of the global role played by CsrA in balancing the opposing physiological demands of stress resistance with the capacity for growth and modulating host interactions.IMPORTANCETo colonize/infect the mammalian intestinal tract, bacteria must survive exposure to the extreme acidity of the stomach. E. coli does this by expressing proteins that neutralize cytoplasmic acidity and cope with molecular damage caused by low pH. Because of the metabolic cost of these processes, genes for surviving acid stress are tightly regulated. Here, we show that CsrA negatively regulates the cascade of expression responsible for the acid stress response. Increased expression of acid response genes due to csrA disruption improved survival at extremely low pH but inhibited growth under mildly acidic conditions. Our findings define a new layer of regulation in the acid stress response of E. coli and a novel physiological function for CsrA.
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Affiliation(s)
- Mark G. Gorelik
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Archana Pannuri
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Alyssa C. Walker
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Christine Pourciau
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Daniel Czyz
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
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3
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Li J, Ma Q, Huang J, Liu Y, Zhou J, Yu S, Zhang Q, Lin Y, Wang L, Zou J, Li Y. Small RNA SmsR1 modulates acidogenicity and cariogenic virulence by affecting protein acetylation in Streptococcus mutans. PLoS Pathog 2024; 20:e1012147. [PMID: 38620039 PMCID: PMC11045139 DOI: 10.1371/journal.ppat.1012147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 04/25/2024] [Accepted: 03/25/2024] [Indexed: 04/17/2024] Open
Abstract
Post-transcriptional regulation by small RNAs and post-translational modifications (PTM) such as lysine acetylation play fundamental roles in physiological circuits, offering rapid responses to environmental signals with low energy consumption. Yet, the interplay between these regulatory systems remains underexplored. Here, we unveil the cross-talk between sRNAs and lysine acetylation in Streptococcus mutans, a primary cariogenic pathogen known for its potent acidogenic virulence. Through systematic overexpression of sRNAs in S. mutans, we identified sRNA SmsR1 as a critical player in modulating acidogenicity, a key cariogenic virulence feature in S. mutans. Furthermore, combined with the analysis of predicted target mRNA and transcriptome results, potential target genes were identified and experimentally verified. A direct interaction between SmsR1 and 5'-UTR region of pdhC gene was determined by in vitro binding assays. Importantly, we found that overexpression of SmsR1 reduced the expression of pdhC mRNA and increased the intracellular concentration of acetyl-CoA, resulting in global changes in protein acetylation levels. This was verified by acetyl-proteomics in S. mutans, along with an increase in acetylation level and decreased activity of LDH. Our study unravels a novel regulatory paradigm where sRNA bridges post-transcriptional regulation with post-translational modification, underscoring bacterial adeptness in fine-tuning responses to environmental stress.
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Affiliation(s)
- Jing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qizhao Ma
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jun Huang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yaqi Liu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Jing Zhou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Shuxing Yu
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Qiong Zhang
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yongwang Lin
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Operative Dentistry and Endodontics, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Lingyun Wang
- Section of Infectious Diseases, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, United States of America
| | - Jing Zou
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
- Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
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4
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Fesenko I, Sahakyan H, Shabalina SA, Koonin EV. The Cryptic Bacterial Microproteome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.17.580829. [PMID: 38903115 PMCID: PMC11188072 DOI: 10.1101/2024.02.17.580829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Microproteins encoded by small open reading frames (smORFs) comprise the "dark matter" of proteomes. Although functional microproteins were identified in diverse organisms from all three domains of life, bacterial smORFs remain poorly characterized. In this comprehensive study of intergenic smORFs (ismORFs, 15-70 codons) in 5,668 bacterial genomes of the family Enterobacteriaceae, we identified 67,297 clusters of ismORFs subject to purifying selection. The ismORFs mainly code for hydrophobic, potentially transmembrane, unstructured, or minimally structured microproteins. Using AlphaFold Multimer, we predicted interactions of some of the predicted microproteins encoded by transcribed ismORFs with proteins encoded by neighboring genes, revealing the potential of microproteins to regulate the activity of various proteins, particularly, under stress. We compiled a catalog of predicted microprotein families with different levels of evidence from synteny analysis, structure prediction, and transcription and translation data. This study offers a resource for investigation of biological functions of microproteins.
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Affiliation(s)
- Igor Fesenko
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Harutyun Sahakyan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Svetlana A. Shabalina
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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5
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Schnoor SB, Neubauer P, Gimpel M. Recent insights into the world of dual-function bacterial sRNAs. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023:e1824. [PMID: 38039556 DOI: 10.1002/wrna.1824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 12/03/2023]
Abstract
Dual-function sRNAs refer to a small subgroup of small regulatory RNAs that merges base-pairing properties of antisense RNAs with peptide-encoding properties of mRNA. Both functions can be part of either same or in another metabolic pathway. Here, we want to update the knowledge of to the already known dual-function sRNAs and review the six new sRNAs found since 2017 regarding their structure, functional mechanisms, evolutionary conservation, and role in the regulation of distinct biological/physiological processes. The increasing identification of dual-function sRNAs through bioinformatics approaches, RNomics and RNA-sequencing and the associated increase in regulatory understanding will likely continue to increase at the same rate in the future. This may improve our understanding of the physiology, virulence and resistance of bacteria, as well as enable their use in technical applications. This article is categorized under: Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.
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Affiliation(s)
| | - Peter Neubauer
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
| | - Matthias Gimpel
- Department of Bioprocess Engineering, Technische Universitat Berlin, Berlin, Germany
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6
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Mohsen JJ, Martel AA, Slavoff SA. Microproteins-Discovery, structure, and function. Proteomics 2023; 23:e2100211. [PMID: 37603371 PMCID: PMC10841188 DOI: 10.1002/pmic.202100211] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/03/2023] [Accepted: 08/10/2023] [Indexed: 08/22/2023]
Abstract
Advances in proteogenomic technologies have revealed hundreds to thousands of translated small open reading frames (sORFs) that encode microproteins in genomes across evolutionary space. While many microproteins have now been shown to play critical roles in biology and human disease, a majority of recently identified microproteins have little or no experimental evidence regarding their functionality. Computational tools have some limitations for analysis of short, poorly conserved microprotein sequences, so additional approaches are needed to determine the role of each member of this recently discovered polypeptide class. A currently underexplored avenue in the study of microproteins is structure prediction and determination, which delivers a depth of functional information. In this review, we provide a brief overview of microprotein discovery methods, then examine examples of microprotein structures (and, conversely, intrinsic disorder) that have been experimentally determined using crystallography, cryo-electron microscopy, and NMR, which provide insight into their molecular functions and mechanisms. Additionally, we discuss examples of predicted microprotein structures that have provided insight or context regarding their function. Analysis of microprotein structure at the angstrom level, and confirmation of predicted structures, therefore, has potential to identify translated microproteins that are of biological importance and to provide molecular mechanism for their in vivo roles.
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Affiliation(s)
- Jessica J. Mohsen
- Department of Chemistry, Yale University, New Haven, CT, USA
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Alina A. Martel
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
| | - Sarah A. Slavoff
- Department of Chemistry, Yale University, New Haven, CT, USA
- Institute of Biomolecular Design and Discovery, Yale University, West Haven, CT, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
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7
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Jordan B, Weidenbach K, Schmitz RA. The power of the small: the underestimated role of small proteins in bacterial and archaeal physiology. Curr Opin Microbiol 2023; 76:102384. [PMID: 37776678 DOI: 10.1016/j.mib.2023.102384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/04/2023] [Accepted: 09/04/2023] [Indexed: 10/02/2023]
Abstract
Small proteins encoded by small open-reading frames (sORFs) (≤70 aa) were overlooked for decades due to methodological reasons and are thus often missing in genome annotations. Novel detection methods such as ribosome profiling (Ribo-Seq) and mass spectrometry optimized for small proteins (peptidomics) have opened up a new field of interest and several catalogs of small proteins in bacteria and archaea have been recently reported. Many translated sORFs have been discovered in genomic locations previously thought to be noncoding, such as 5' or 3' untranslated regions or well-studied regulatory small RNAs (sRNAs). Even within longer ORFs, additional functional sORFs have been detected. Today, only a small proportion is characterized, but those small proteins indicate important and diverse functions in cellular physiology. Here, we summarize recently characterized small proteins involved in microbial metabolism.
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Affiliation(s)
- Britta Jordan
- Institute for General Microbiology, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Katrin Weidenbach
- Institute for General Microbiology, Christian-Albrechts-University, 24118 Kiel, Germany
| | - Ruth A Schmitz
- Institute for General Microbiology, Christian-Albrechts-University, 24118 Kiel, Germany.
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8
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Aoyama JJ, Storz G. Two for one: regulatory RNAs that encode small proteins. Trends Biochem Sci 2023; 48:1035-1043. [PMID: 37777390 PMCID: PMC10841219 DOI: 10.1016/j.tibs.2023.09.002] [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: 07/11/2023] [Revised: 09/02/2023] [Accepted: 09/08/2023] [Indexed: 10/02/2023]
Abstract
RNAs are commonly categorized as being either protein-coding mRNAs or noncoding RNAs. However, an increasing number of transcripts, in organisms ranging from bacteria to humans, are being found to have both coding and noncoding functions. In some cases, the sequences encoding the protein and the regulatory RNA functions are separated, while in other cases the sequences overlap. The protein and RNA can regulate similar or distinct pathways. Here we describe examples illustrating how these dual-function (also denoted bifunctional or dual-component) RNAs are identified and their mechanisms of action and cellular roles. We also discuss the synergy or competition between coding and RNA activity and how these regulators evolved, as well as how more dual-function RNAs might be discovered and exploited.
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Affiliation(s)
- Jordan J Aoyama
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892-4417, USA
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892-4417, USA.
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9
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Rojano-Nisimura AM, Simmons TR, Leistra AN, Mihailovic MK, Buchser R, Ekdahl AM, Joseph I, Curtis NC, Contreras LM. CsrA selectively modulates sRNA-mRNA regulator outcomes. Front Mol Biosci 2023; 10:1249528. [PMID: 38116378 PMCID: PMC10729762 DOI: 10.3389/fmolb.2023.1249528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/10/2023] [Indexed: 12/21/2023] Open
Abstract
Post-transcriptional regulation, by small RNAs (sRNAs) as well as the global Carbon Storage Regulator A (CsrA) protein, play critical roles in bacterial metabolic control and stress responses. The CsrA protein affects selective sRNA-mRNA networks, in addition to regulating transcription factors and sigma factors, providing additional avenues of cross talk between other stress-response regulators. Here, we expand the known set of sRNA-CsrA interactions and study their regulatory effects. In vitro binding assays confirm novel CsrA interactions with ten sRNAs, many of which are previously recognized as key regulatory nodes. Of those 10 sRNA, we identify that McaS, FnrS, SgrS, MicL, and Spot42 interact directly with CsrA in vivo. We find that the presence of CsrA impacts the downstream regulation of mRNA targets of the respective sRNA. In vivo evidence supports enhanced CsrA McaS-csgD mRNA repression and showcases CsrA-dependent repression of the fucP mRNA via the Spot42 sRNA. We additionally identify SgrS and FnrS as potential new sRNA sponges of CsrA. Overall, our results further support the expanding impact of the Csr system on cellular physiology via CsrA impact on the regulatory roles of these sRNAs.
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Affiliation(s)
| | - Trevor R. Simmons
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Abigail N. Leistra
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Mia K. Mihailovic
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Ryan Buchser
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Alyssa M. Ekdahl
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Isabella Joseph
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Nicholas C. Curtis
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
| | - Lydia M. Contreras
- Biochemistry Graduate Program, University of Texas at Austin, Austin, TX, United States
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX, United States
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10
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Pokorzynski ND, Groisman EA. How Bacterial Pathogens Coordinate Appetite with Virulence. Microbiol Mol Biol Rev 2023; 87:e0019822. [PMID: 37358444 PMCID: PMC10521370 DOI: 10.1128/mmbr.00198-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/27/2023] Open
Abstract
Cells adjust growth and metabolism to nutrient availability. Having access to a variety of carbon sources during infection of their animal hosts, facultative intracellular pathogens must efficiently prioritize carbon utilization. Here, we discuss how carbon source controls bacterial virulence, with an emphasis on Salmonella enterica serovar Typhimurium, which causes gastroenteritis in immunocompetent humans and a typhoid-like disease in mice, and propose that virulence factors can regulate carbon source prioritization by modifying cellular physiology. On the one hand, bacterial regulators of carbon metabolism control virulence programs, indicating that pathogenic traits appear in response to carbon source availability. On the other hand, signals controlling virulence regulators may impact carbon source utilization, suggesting that stimuli that bacterial pathogens experience within the host can directly impinge on carbon source prioritization. In addition, pathogen-triggered intestinal inflammation can disrupt the gut microbiota and thus the availability of carbon sources. By coordinating virulence factors with carbon utilization determinants, pathogens adopt metabolic pathways that may not be the most energy efficient because such pathways promote resistance to antimicrobial agents and also because host-imposed deprivation of specific nutrients may hinder the operation of certain pathways. We propose that metabolic prioritization by bacteria underlies the pathogenic outcome of an infection.
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Affiliation(s)
- Nick D. Pokorzynski
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Microbial Sciences Institute, West Haven, Connecticut, USA
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11
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Abstract
Small regulatory RNA (sRNAs) are key mediators of posttranscriptional gene control in bacteria. Assisted by RNA-binding proteins, a single sRNA often modulates the expression of dozens of genes, and thus sRNAs frequently adopt central roles in regulatory networks. Posttranscriptional regulation by sRNAs comes with several unique features that cannot be achieved by transcriptional regulators. However, for optimal network performance, transcriptional and posttranscriptional control mechanisms typically go hand-in-hand. This view is reflected by the ever-growing class of mixed network motifs involving sRNAs and transcription factors, which are ubiquitous in biology and whose regulatory properties we are beginning to understand. In addition, sRNA activity can be antagonized by base-pairing with sponge RNAs, adding yet another layer of complexity to these networks. In this article, we summarize the regulatory concepts underlying sRNA-mediated gene control in bacteria and discuss how sRNAs shape the output of a network, focusing on several key examples.
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Affiliation(s)
- Kai Papenfort
- Institute of Microbiology, Friedrich Schiller University Jena, Jena, Germany;
- Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
| | - Sahar Melamed
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel;
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12
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Ferrara S, Brignoli T, Bertoni G. Little reason to call them small noncoding RNAs. Front Microbiol 2023; 14:1191166. [PMID: 37455713 PMCID: PMC10339803 DOI: 10.3389/fmicb.2023.1191166] [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: 03/21/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023] Open
Abstract
Hundreds of different species of small RNAs can populate a bacterial cell. This small transcriptome contains important information for the adaptation of cellular physiology to environmental changes. Underlying cellular networks involving small RNAs are RNA-RNA and RNA-protein interactions, which are often intertwined. In addition, small RNAs can function as mRNAs. In general, small RNAs are referred to as noncoding because very few are known to contain translated open reading frames. In this article, we intend to highlight that the number of small RNAs that fall within the set of translated RNAs is bound to increase. In addition, we aim to emphasize that the dynamics of the small transcriptome involve different functional codes, not just the genetic code. Therefore, since the role of small RNAs is always code-driven, we believe that there is little reason to continue calling them small noncoding RNAs.
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13
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Krol E, Werel L, Essen LO, Becker A. Structural and functional diversity of bacterial cyclic nucleotide perception by CRP proteins. MICROLIFE 2023; 4:uqad024. [PMID: 37223727 PMCID: PMC10187061 DOI: 10.1093/femsml/uqad024] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/07/2023] [Accepted: 04/28/2023] [Indexed: 05/25/2023]
Abstract
Cyclic AMP (cAMP) is a ubiquitous second messenger synthesized by most living organisms. In bacteria, it plays highly diverse roles in metabolism, host colonization, motility, and many other processes important for optimal fitness. The main route of cAMP perception is through transcription factors from the diverse and versatile CRP-FNR protein superfamily. Since the discovery of the very first CRP protein CAP in Escherichia coli more than four decades ago, its homologs have been characterized in both closely related and distant bacterial species. The cAMP-mediated gene activation for carbon catabolism by a CRP protein in the absence of glucose seems to be restricted to E. coli and its close relatives. In other phyla, the regulatory targets are more diverse. In addition to cAMP, cGMP has recently been identified as a ligand of certain CRP proteins. In a CRP dimer, each of the two cyclic nucleotide molecules makes contacts with both protein subunits and effectuates a conformational change that favors DNA binding. Here, we summarize the current knowledge on structural and physiological aspects of E. coli CAP compared with other cAMP- and cGMP-activated transcription factors, and point to emerging trends in metabolic regulation related to lysine modification and membrane association of CRP proteins.
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Affiliation(s)
- Elizaveta Krol
- Department of Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35043 Marburg, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35043 Marburg, Germany
| | - Laura Werel
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Lars Oliver Essen
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany
| | - Anke Becker
- Corresponding author. Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Karl-von-Frisch-Str. 14, 35043 Marburg. E-mail:
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14
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Rojano-Nisimura AM, Simmons TR, Leistra AN, Mihailovic MK, Buchser R, Ekdahl AM, Joseph I, Curtis NC, Contreras LM. CsrA Shows Selective Regulation of sRNA-mRNA Networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.29.534774. [PMID: 37034808 PMCID: PMC10081199 DOI: 10.1101/2023.03.29.534774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Post-transcriptional regulation, by small RNAs (sRNAs) as well as the global Carbon Storage Regulator A (CsrA) protein, play critical roles in bacterial metabolic control and stress responses. The CsrA protein affects selective sRNA-mRNA networks, in addition to regulating transcription factors and sigma factors, providing additional avenues of cross talk between other stress-response regulators. Here, we expand the known set of sRNA-CsrA interactions and study their regulatory effects. In vitro binding assays confirm novel CsrA interactions with ten sRNAs, many of which are previously recognized as key regulatory nodes. Of those 10 sRNA, we identify that McaS, FnrS, SgrS, MicL, and Spot42 interact with CsrA in vivo. We find that the presence of CsrA impacts the downstream regulation of mRNA targets of the respective sRNA. In vivo evidence supports enhanced CsrA McaS-csgD mRNA repression and showcase CsrA-dependent repression of the fucP mRNA via the Spot42 sRNA. We additionally identify SgrS and FnrS as potential new sRNA sponges of CsrA. Overall, our results further support the expanding impact of the Csr system on cellular physiology via CsrA impact on the regulatory roles of these sRNAs.
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Affiliation(s)
| | - Trevor R. Simmons
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Abigail N. Leistra
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Mia K. Mihailovic
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Ryan Buchser
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Alyssa M. Ekdahl
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Isabella Joseph
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Nicholas C. Curtis
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
| | - Lydia M. Contreras
- Biochemistry Graduate Program, University of Texas at Austin, 100 E. 24th Street Stop A6500, Austin, TX 78712, USA
- McKetta Department of Chemical Engineering, University of Texas at Austin, 200 E. Dean Keeton St. Stop C0400, Austin, TX 78712, USA
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15
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Cai X, Qin J, Li X, Yuan T, Yan B, Cai J. LipR functions as an intracellular pH regulator in Bacillus thuringiensis under glucose conditions. MLIFE 2023; 2:58-72. [PMID: 38818337 PMCID: PMC10989752 DOI: 10.1002/mlf2.12055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/06/2022] [Accepted: 12/07/2022] [Indexed: 06/01/2024]
Abstract
Intracellular pH critically affects various biological processes, and an appropriate cytoplasmic pH is essential for ensuring bacterial growth. Glucose is the preferred carbon source for most heterotrophs; however, excess glucose often causes the accumulation of acidic metabolites, lowering the intracellular pH and inhibiting bacterial growth. Bacillus thuringiensis can effectively cope with glucose-induced stress; unfortunately, little is known about the regulators involved in this process. Here, we document that the target of the dual-function sRNA YhfH, the lipR gene, encodes a LacI-family transcription factor LipR as an intracellular pH regulator when B. thuringiensis BMB171 is suddenly exposed to glucose. Under glucose conditions, lipR deletion leads to early growth arrest by causing a rapid decrease in intracellular pH (~5.4). Then, the direct targets and a binding motif (GAWAWCRWTWTCAT) of LipR were identified based on the electrophoretic mobility shift assay, the DNase-I footprinting assay, and RNA sequencing, and the gapN gene encoding a key enzyme in glycolysis was directly inhibited by LipR. Furthermore, Ni2+ is considered a possible effector for LipR. In addition to YhfH, the lipR expression was coregulated by itself, CcpA, and AbrB. Our study reveals that LipR plays a balancing role between glucose metabolism and intracellular pH in B. thuringiensis subjected to glucose stress.
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Affiliation(s)
- Xia Cai
- Department of Microbiology, College of Life SciencesNankai UniversityTianjinChina
- School of Life Science and EngineeringLanzhou University of TechnologyLanzhouChina
| | - Jiaxin Qin
- Department of Microbiology, College of Life SciencesNankai UniversityTianjinChina
| | - Xuelian Li
- Department of Microbiology, College of Life SciencesNankai UniversityTianjinChina
| | - Taoxiong Yuan
- Department of Microbiology, College of Life SciencesNankai UniversityTianjinChina
| | - Bing Yan
- Department of Microbiology, College of Life SciencesNankai UniversityTianjinChina
| | - Jun Cai
- Department of Microbiology, College of Life SciencesNankai UniversityTianjinChina
- Key Laboratory of Molecular Microbiology and TechnologyMinistry of EducationTianjinChina
- Tianjin Key Laboratory of Microbial Functional GenomicsTianjinChina
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16
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Moreno R, Rojo F. The importance of understanding the regulation of bacterial metabolism. Environ Microbiol 2023; 25:54-58. [PMID: 35859345 PMCID: PMC10084369 DOI: 10.1111/1462-2920.16123] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Accepted: 06/30/2022] [Indexed: 01/21/2023]
Affiliation(s)
- Renata Moreno
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - Fernando Rojo
- Department of Microbial Biotechnology, Centro Nacional de Biotecnología, CSIC, Madrid, Spain
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17
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Chihara K, Gerovac M, Hör J, Vogel J. Global profiling of the RNA and protein complexes of Escherichia coli by size exclusion chromatography followed by RNA sequencing and mass spectrometry (SEC-seq). RNA (NEW YORK, N.Y.) 2022; 29:rna.079439.122. [PMID: 36328526 PMCID: PMC9808575 DOI: 10.1261/rna.079439.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/27/2022] [Indexed: 06/16/2023]
Abstract
New methods for the global identification of RNA-protein interactions have led to greater recognition of the abundance and importance of RNA-binding proteins (RBPs) in bacteria. Here, we expand this tool kit by developing SEC-seq, a method based on a similar concept as the established Grad-seq approach. In Grad-seq, cellular RNA and protein complexes of a bacterium of interest are separated in a glycerol gradient, followed by high-throughput RNA-sequencing and mass spectrometry analyses of individual gradient fractions. New RNA-protein complexes are predicted based on the similarity of their elution profiles. In SEC-seq, we have replaced the glycerol gradient with separation by size exclusion chromatography, which shortens operation times and offers greater potential for automation. Applying SEC-seq to Escherichia coli, we find that the method provides a higher resolution than Grad-seq in the lower molecular weight range up to ~500 kDa. This is illustrated by the ability of SEC-seq to resolve two distinct, but similarly sized complexes of the global translational repressor CsrA with either of its antagonistic small RNAs, CsrB and CsrC. We also characterized changes in the SEC-seq profiles of the small RNA MicA upon deletion of its RNA chaperones Hfq and ProQ and investigated the redistribution of these two proteins upon RNase treatment. Overall, we demonstrate that SEC-seq is a tractable and reproducible method for the global profiling of bacterial RNA-protein complexes that offers the potential to discover yet-unrecognized associations between bacterial RNAs and proteins.
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Affiliation(s)
- Kotaro Chihara
- Helmholtz Institute for RNA-based Infection Research, Würzburg, Germany
| | | | - Jens Hör
- Weizmann Institute, Rehovot, Israel
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18
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Ravindran S. Profile of Gisela Storz. Proc Natl Acad Sci U S A 2022; 119:e2204150119. [PMID: 35486700 PMCID: PMC9171377 DOI: 10.1073/pnas.2204150119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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19
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Miyakoshi M, Morita T, Kobayashi A, Berger A, Takahashi H, Gotoh Y, Hayashi T, Tanaka K. Glutamine synthetase mRNA releases sRNA from its 3'UTR to regulate carbon/nitrogen metabolic balance in Enterobacteriaceae. eLife 2022; 11:82411. [PMID: 36440827 PMCID: PMC9731577 DOI: 10.7554/elife.82411] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/27/2022] [Indexed: 11/29/2022] Open
Abstract
Glutamine synthetase (GS) is the key enzyme of nitrogen assimilation induced under nitrogen limiting conditions. The carbon skeleton of glutamate and glutamine, 2-oxoglutarate, is supplied from the TCA cycle, but how this metabolic flow is controlled in response to nitrogen availability remains unknown. We show that the expression of the E1o component of 2-oxoglutarate dehydrogenase, SucA, is repressed under nitrogen limitation in Salmonella enterica and Escherichia coli. The repression is exerted at the post-transcriptional level by an Hfq-dependent sRNA GlnZ generated from the 3'UTR of the GS-encoding glnA mRNA. Enterobacterial GlnZ variants contain a conserved seed sequence and primarily regulate sucA through base-pairing far upstream of the translation initiation region. During growth on glutamine as the nitrogen source, the glnA 3'UTR deletion mutants expressed SucA at higher levels than the S. enterica and E. coli wild-type strains, respectively. In E. coli, the transcriptional regulator Nac also participates in the repression of sucA. Lastly, this study clarifies that the release of GlnZ from the glnA mRNA by RNase E is essential for the post-transcriptional regulation of sucA. Thus, the mRNA coordinates the two independent functions to balance the supply and demand of the fundamental metabolites.
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Affiliation(s)
- Masatoshi Miyakoshi
- Department of Infection Biology, Faculty of Medicine, University of TsukubaTsukubaJapan,Transborder Medical Research Center, University of TsukubaTsukubaJapan,International Joint Degree Master’s Program in Agro-Biomedical Science in Food and Health (GIP-TRIAD), University of TsukubaTsukubaJapan
| | - Teppei Morita
- Institute for Advanced Biosciences, Keio UniversityTsuruokaJapan,Graduate School of Media and Governance, Keio UniversityFujisawaJapan
| | - Asaki Kobayashi
- Transborder Medical Research Center, University of TsukubaTsukubaJapan
| | - Anna Berger
- International Joint Degree Master’s Program in Agro-Biomedical Science in Food and Health (GIP-TRIAD), University of TsukubaTsukubaJapan
| | | | - Yasuhiro Gotoh
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu UniversityFukuokaJapan
| | - Tetsuya Hayashi
- Department of Bacteriology, Faculty of Medical Sciences, Kyushu UniversityFukuokaJapan
| | - Kan Tanaka
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of TechnologyYokohamaJapan
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