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Raghunandanan S, Priya R, Alanazi F, Lybecker MC, Schlax P, Yang X. A Fur family protein BosR is a novel RNA-binding protein that controls rpoS RNA stability in the Lyme disease pathogen. Nucleic Acids Res 2024; 52:5320-5335. [PMID: 38366569 PMCID: PMC11109971 DOI: 10.1093/nar/gkae114] [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: 10/13/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/18/2024] Open
Abstract
The σ54-σS sigma factor cascade plays a central role in regulating differential gene expression during the enzootic cycle of Borreliella burgdorferi, the Lyme disease pathogen. In this pathway, the primary transcription of rpoS (which encodes σS) is under the control of σ54 which is activated by a bacterial enhancer-binding protein (EBP), Rrp2. The σ54-dependent activation in B. burgdorferi has long been thought to be unique, requiring an additional factor, BosR, a homologue of classical Fur/PerR repressor/activator. However, how BosR is involved in this σ54-dependent activation remains unclear and perplexing. In this study, we demonstrate that BosR does not function as a regulator for rpoS transcriptional activation. Instead, it functions as a novel RNA-binding protein that governs the turnover rate of rpoS mRNA. We further show that BosR directly binds to the 5' untranslated region (UTR) of rpoS mRNA, and the binding region overlaps with a region required for rpoS mRNA degradation. Mutations within this 5'UTR region result in BosR-independent RpoS production. Collectively, these results uncover a novel role of Fur/PerR family regulators as RNA-binding proteins and redefine the paradigm of the σ54-σS pathway in B. burgdorferi.
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Affiliation(s)
- Sajith Raghunandanan
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Raj Priya
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Fuad Alanazi
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Saud University, Riyadh 12372, Saudi Arabia
| | - Meghan C Lybecker
- Bacterial Diseases Branch, Division of Vector-Borne Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Center for Disease Control and Prevention, Fort Collins, CO, USA
| | - Paula Jean Schlax
- Department of Chemistry and Biochemistry, Bates College, Lewiston, ME, USA
| | - X Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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Bathke J, Gauernack AS, Rupp O, Weber L, Preusser C, Lechner M, Rossbach O, Goesmann A, Evguenieva-Hackenberg E, Klug G. iCLIP analysis of RNA substrates of the archaeal exosome. BMC Genomics 2020; 21:797. [PMID: 33198623 PMCID: PMC7667871 DOI: 10.1186/s12864-020-07200-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 10/27/2020] [Indexed: 12/25/2022] Open
Abstract
Background The archaeal exosome is an exoribonucleolytic multiprotein complex, which degrades single-stranded RNA in 3′ to 5′ direction phosphorolytically. In a reverse reaction, it can add A-rich tails to the 3′-end of RNA. The catalytic center of the exosome is in the aRrp41 subunit of its hexameric core. Its RNA-binding subunits aRrp4 and aDnaG confer poly(A) preference to the complex. The archaeal exosome was intensely characterized in vitro, but still little is known about its interaction with natural substrates in the cell, particularly because analysis of the transcriptome-wide interaction of an exoribonuclease with RNA is challenging. Results To determine binding sites of the exosome to RNA on a global scale, we performed individual-nucleotide resolution UV crosslinking and immunoprecipitation (iCLIP) analysis with antibodies directed against aRrp4 and aRrp41 of the chrenarchaeon Sulfolobus solfataricus. A relatively high proportion (17–19%) of the obtained cDNA reads could not be mapped to the genome. Instead, they corresponded to adenine-rich RNA tails, which are post-transcriptionally synthesized by the exosome, and to circular RNAs (circRNAs). We identified novel circRNAs corresponding to 5′ parts of two homologous, transposase-related mRNAs. To detect preferred substrates of the exosome, the iCLIP reads were compared to the transcript abundance using RNA-Seq data. Among the strongly enriched exosome substrates were RNAs antisense to tRNAs, overlapping 3′-UTRs and RNAs containing poly(A) stretches. The majority of the read counts and crosslink sites mapped in mRNAs. Furthermore, unexpected crosslink sites clustering at 5′-ends of RNAs was detected. Conclusions In this study, RNA targets of an exoribonuclease were analyzed by iCLIP. The data documents the role of the archaeal exosome as an exoribonuclease and RNA-tailing enzyme interacting with all RNA classes, and underlines its role in mRNA turnover, which is important for adaptation of prokaryotic cells to changing environmental conditions. The clustering of crosslink sites near 5′-ends of genes suggests simultaneous binding of both RNA ends by the S. solfataricus exosome. This may serve to prevent translation of mRNAs dedicated to degradation in 3′-5′ direction. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-020-07200-x.
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Affiliation(s)
- Jochen Bathke
- Institute of Microbiology and Molecular Biology, Justus-Liebig-University, 35392, Giessen, Germany.,Institute of Bioinformatics and Systems Biology, Justus-Liebig-University, 35392, Giessen, Germany
| | - A Susann Gauernack
- Institute of Microbiology and Molecular Biology, Justus-Liebig-University, 35392, Giessen, Germany
| | - Oliver Rupp
- Institute of Bioinformatics and Systems Biology, Justus-Liebig-University, 35392, Giessen, Germany
| | - Lennart Weber
- Institute of Microbiology and Molecular Biology, Justus-Liebig-University, 35392, Giessen, Germany
| | - Christian Preusser
- Institute of Biochemistry, Justus-Liebig-University, 35392, Giessen, Germany
| | - Marcus Lechner
- Center for Synthetic Microbiology & Department of Pharmaceutical Chemistry, Philipps-University Marburg, 35032, Marburg, Germany
| | - Oliver Rossbach
- Institute of Biochemistry, Justus-Liebig-University, 35392, Giessen, Germany
| | - Alexander Goesmann
- Institute of Bioinformatics and Systems Biology, Justus-Liebig-University, 35392, Giessen, Germany
| | | | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, Justus-Liebig-University, 35392, Giessen, Germany
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Evguenieva-Hackenberg E, Gauernack AS, Hou L, Klug G. Enzymatic Analysis of Reconstituted Archaeal Exosomes. Methods Mol Biol 2020; 2062:63-79. [PMID: 31768972 DOI: 10.1007/978-1-4939-9822-7_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
The archaeal exosome is a protein complex with phosphorolytic activity. It is built of a catalytically active hexameric ring containing the archaeal Rrp41 and Rrp42 proteins, and a heteromeric RNA-binding platform. The platform contains a heterotrimer of the archaeal Rrp4 and Csl4 proteins (which harbor S1 and KH or Zn-ribbon RNA binding domains), and comprises additional archaea-specific subunits. The latter are represented by the archaeal DnaG protein, which harbors a novel RNA-binding domain and tightly interacts with the majority of the exosome isoforms, and Nop5, known as a part of an rRNA methylating complex and found to associate with the archaeal exosome at late stationary phase. Although in the cell the archaeal exosome exists in different isoforms with heterotrimeric Rrp4-Csl4-caps, in vitro it is possible to reconstitute complexes with defined, homotrimeric caps and to study the impact of each RNA-binding subunit on exoribonucleolytic degradation and on polynucleotidylation of RNA. Here we describe procedures for reconstitution of isoforms of the Sulfolobus solfataricus exosome and for set-up of RNA degradation and polyadenylation assays.
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Affiliation(s)
| | - A Susann Gauernack
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Linlin Hou
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Giessen, Germany
| | - Gabriele Klug
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Giessen, Germany.
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Blombach F, Matelska D, Fouqueau T, Cackett G, Werner F. Key Concepts and Challenges in Archaeal Transcription. J Mol Biol 2019; 431:4184-4201. [PMID: 31260691 DOI: 10.1016/j.jmb.2019.06.020] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 06/18/2019] [Accepted: 06/20/2019] [Indexed: 12/17/2022]
Abstract
Transcription is enabled by RNA polymerase and general factors that allow its progress through the transcription cycle by facilitating initiation, elongation and termination. The transitions between specific stages of the transcription cycle provide opportunities for the global and gene-specific regulation of gene expression. The exact mechanisms and the extent to which the different steps of transcription are exploited for regulation vary between the domains of life, individual species and transcription units. However, a surprising degree of conservation is apparent. Similar key steps in the transcription cycle can be targeted by homologous or unrelated factors providing insights into the mechanisms of RNAP and the evolution of the transcription machinery. Archaea are bona fide prokaryotes but employ a eukaryote-like transcription system to express the information of bacteria-like genomes. Thus, archaea provide the means not only to study transcription mechanisms of interesting model systems but also to test key concepts of regulation in this arena. In this review, we discuss key principles of archaeal transcription, new questions that still await experimental investigation, and how novel integrative approaches hold great promise to fill this gap in our knowledge.
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Affiliation(s)
- Fabian Blombach
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
| | - Dorota Matelska
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Thomas Fouqueau
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Gwenny Cackett
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom
| | - Finn Werner
- Institute of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, United Kingdom.
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Gauernack AS, Lassek C, Hou L, Dzieciolowski J, Evguenieva-Hackenberg E, Klug G. Nop5 interacts with the archaeal RNA exosome. FEBS Lett 2017; 591:4039-4048. [PMID: 29159940 DOI: 10.1002/1873-3468.12915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 11/01/2017] [Accepted: 11/08/2017] [Indexed: 01/02/2023]
Abstract
The archaeal exosome, a protein complex responsible for phosphorolytic degradation and tailing of RNA, has an RNA-binding platform containing Rrp4, Csl4, and DnaG. Aiming to detect novel interaction partners of the exosome, we copurified Nop5, which is a part of an rRNA methylating ribonucleoprotein complex, with the exosome of Sulfolobus solfataricus grown to a late stationary phase. We demonstrated the capability of Nop5 to bind to the exosome with a homotrimeric Rrp4-cap and to increase the proportion of polyadenylated RNAin vitro, suggesting that Nop5 is a dual-function protein. Since tailing of RNA probably serves to enhance RNA degradation, association of Nop5 with the archaeal exosome in the stationary phase may enhance tailing and degradation of RNA as survival strategy.
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Affiliation(s)
- A Susann Gauernack
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
| | - Christian Lassek
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
| | - Linlin Hou
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
| | - Julia Dzieciolowski
- Biochemistry and Molecular Biology, Interdisciplinary Research Center, Justus Liebig University Giessen, Germany
| | | | - Gabriele Klug
- Institute for Microbiology and Molecular Biology, Justus-Liebig-University Giessen, Germany
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Phung DK, Clouet-d'Orval B. Tips and tricks to probe the RNA-degrading activities of hyperthermophilic archaeal β-CASP ribonucleases. Methods Mol Biol 2015; 1259:453-466. [PMID: 25579601 DOI: 10.1007/978-1-4939-2214-7_26] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The importance of ribonucleases in posttranscriptional control of gene expression has been established in Eukarya and Bacteria for over a decade. However, this process has been overlooked in Archaea, which are of universal importance to elucidate fundamental biological mechanisms and to study the evolution of life on Earth. Very few ribonucleolytic activities have been reported in Archaea, and RNA metabolism pathways wait to be described. Recently we have identified two major groups of archaeal ribonucleases, aCPSF1 and aRNase J, which are members of the β-CASP metallo-β-lactamase family. Here, we describe in vitro methods to characterize the endo- and exoribonucleolytic activities of hyperthermophilic archaeal β-CASP ribonucleases. The use of various labeled RNA substrates allows defining the specificity of RNA cleavage and the directionality of the exoribonucleolytic trimming activity of the archaeal enzymes which work at high temperature. Elucidating in vitro ribonucleolytic activities is one step toward the understanding of the role of β-CASP ribonucleases in RNA metabolism pathways in archaeal cells.
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Affiliation(s)
- Duy Khanh Phung
- Centre National de la Recherche Scientifique, UMR 5100-LMGM, CNRS and Université de Toulouse, 118 route de Narbonne, 31062, Toulouse Cedex 9, France
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Abstract
The importance of gene regulation in the enzootic cycle of Borrelia burgdorferi, the spirochete that causes Lyme disease, is well established. B. burgdorferi regulates gene expression in response to changes in environmental stimuli associated with changing hosts. In this study, we monitored mRNA decay in B. burgdorferi following transcriptional arrest with actinomycin D. The time-dependent decay of transcripts encoding RNA polymerase subunits (rpoA and rpoS), ribosomal proteins (rpsD, rpsK, rpsM, rplQ, and rpsO), a nuclease (pnp), outer surface lipoproteins (ospA and ospC), and a flagellar protein (flaB) have different profiles and indicate half-lives ranging from approximately 1 min to more than 45 min in cells cultured at 35°C. Our results provide a first step in characterizing mRNA decay in B. burgdorferi and in investigating its role in gene expression and regulation.
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Schlüter JP, Reinkensmeier J, Daschkey S, Evguenieva-Hackenberg E, Janssen S, Jänicke S, Becker JD, Giegerich R, Becker A. A genome-wide survey of sRNAs in the symbiotic nitrogen-fixing alpha-proteobacterium Sinorhizobium meliloti. BMC Genomics 2010; 11:245. [PMID: 20398411 PMCID: PMC2873474 DOI: 10.1186/1471-2164-11-245] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2010] [Accepted: 04/17/2010] [Indexed: 12/03/2022] Open
Abstract
Background Small untranslated RNAs (sRNAs) are widespread regulators of gene expression in bacteria. This study reports on a comprehensive screen for sRNAs in the symbiotic nitrogen-fixing alpha-proteobacterium Sinorhizobium meliloti applying deep sequencing of cDNAs and microarray hybridizations. Results A total of 1,125 sRNA candidates that were classified as trans-encoded sRNAs (173), cis-encoded antisense sRNAs (117), mRNA leader transcripts (379), and sense sRNAs overlapping coding regions (456) were identified in a size range of 50 to 348 nucleotides. Among these were transcripts corresponding to 82 previously reported sRNA candidates. Enrichment for RNAs with primary 5'-ends prior to sequencing of cDNAs suggested transcriptional start sites corresponding to 466 predicted sRNA regions. The consensus σ70 promoter motif CTTGAC-N17-CTATAT was found upstream of 101 sRNA candidates. Expression patterns derived from microarray hybridizations provided further information on conditions of expression of a number of sRNA candidates. Furthermore, GenBank, EMBL, DDBJ, PDB, and Rfam databases were searched for homologs of the sRNA candidates identified in this study. Searching Rfam family models with over 1,000 sRNA candidates, re-discovered only those sequences from S. meliloti already known and stored in Rfam, whereas BLAST searches suggested a number of homologs in related alpha-proteobacteria. Conclusions The screening data suggests that in S. meliloti about 3% of the genes encode trans-encoded sRNAs and about 2% antisense transcripts. Thus, this first comprehensive screen for sRNAs applying deep sequencing in an alpha-proteobacterium shows that sRNAs also occur in high number in this group of bacteria.
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Affiliation(s)
- Jan-Philip Schlüter
- Institute of Biology III, Faculty of Biology, University of Freiburg, Freiburg, Germany
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