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Liu SJ, Lin GM, Yuan YQ, Chen W, Zhang JY, Zhang CC. A conserved protein inhibitor brings under check the activity of RNase E in cyanobacteria. Nucleic Acids Res 2024; 52:404-419. [PMID: 38000383 PMCID: PMC10783494 DOI: 10.1093/nar/gkad1094] [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: 03/23/2023] [Revised: 09/21/2023] [Accepted: 10/31/2023] [Indexed: 11/26/2023] Open
Abstract
The bacterial ribonuclease RNase E plays a key role in RNA metabolism. Yet, with a large substrate spectrum and poor substrate specificity, its activity must be well controlled under different conditions. Only a few regulators of RNase E are known, limiting our understanding on posttranscriptional regulatory mechanisms in bacteria. Here we show that, RebA, a protein universally present in cyanobacteria, interacts with RNase E in the cyanobacterium Anabaena PCC 7120. Distinct from those known regulators of RNase E, RebA interacts with the catalytic region of RNase E, and suppresses the cleavage activities of RNase E for all tested substrates. Consistent with the inhibitory function of RebA on RNase E, depletion of RNase E and overproduction of RebA caused formation of elongated cells, whereas the absence of RebA and overproduction of RNase E resulted in a shorter-cell phenotype. We further showed that the morphological changes caused by altered levels of RNase E or RebA are dependent on their physical interaction. The action of RebA represents a new mechanism, potentially conserved in cyanobacteria, for RNase E regulation. Our findings provide insights into the regulation and the function of RNase E, and demonstrate the importance of balanced RNA metabolism in bacteria.
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Affiliation(s)
- Su-Juan Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gui-Ming Lin
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
| | - Yu-Qi Yuan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Wenli Chen
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China
| | - Ju-Yuan Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430070, China
- Key Laboratory of Lake and Watershed Science for Water Security, Chinese Academy of Sciences, Nanjing 210008, China
- Hubei Hongshan Laboratory, Wuhan 430070, China
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2
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Hoffmann UA, Lichtenberg E, Rogh SN, Bilger R, Reimann V, Heyl F, Backofen R, Steglich C, Hess WR, Wilde A. The role of the 5' sensing function of ribonuclease E in cyanobacteria. RNA Biol 2024; 21:1-18. [PMID: 38469716 PMCID: PMC10939160 DOI: 10.1080/15476286.2024.2328438] [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] [Accepted: 03/05/2024] [Indexed: 03/13/2024] Open
Abstract
RNA degradation is critical for synchronising gene expression with changing conditions in prokaryotic and eukaryotic organisms. In bacteria, the preference of the central ribonucleases RNase E, RNase J and RNase Y for 5'-monophosphorylated RNAs is considered important for RNA degradation. For RNase E, the underlying mechanism is termed 5' sensing, contrasting to the alternative 'direct entry' mode, which is independent of monophosphorylated 5' ends. Cyanobacteria, such as Synechocystis sp. PCC 6803 (Synechocystis), encode RNase E and RNase J homologues. Here, we constructed a Synechocystis strain lacking the 5' sensing function of RNase E and mapped on a transcriptome-wide level 283 5'-sensing-dependent cleavage sites. These included so far unknown targets such as mRNAs encoding proteins related to energy metabolism and carbon fixation. The 5' sensing function of cyanobacterial RNase E is important for the maturation of rRNA and several tRNAs, including tRNAGluUUC. This tRNA activates glutamate for tetrapyrrole biosynthesis in plant chloroplasts and in most prokaryotes. Furthermore, we found that increased RNase activities lead to a higher copy number of the major Synechocystis plasmids pSYSA and pSYSM. These results provide a first step towards understanding the importance of the different target mechanisms of RNase E outside Escherichia coli.
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Affiliation(s)
- Ute A. Hoffmann
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
- School of Engineering Sciences in Chemistry, Biotechnology and Health, Science for Life Laboratory, KTH - Royal Institute of Technology, Stockholm, Sweden
| | - Elisabeth Lichtenberg
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Said N. Rogh
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Raphael Bilger
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Viktoria Reimann
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Florian Heyl
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Claudia Steglich
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Wolfgang R. Hess
- Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Annegret Wilde
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
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3
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Xing WY, Liu J, Zhang CC. HetF defines a transition point from commitment to morphogenesis during heterocyst differentiation in the cyanobacterium Anabaena sp. PCC 7120. Mol Microbiol 2023; 120:740-753. [PMID: 37804047 DOI: 10.1111/mmi.15177] [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: 07/27/2023] [Revised: 09/16/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023]
Abstract
The filamentous cyanobacterium Anabaena sp. PCC 7120 is able to form heterocysts for nitrogen fixation. Heterocyst differentiation is initiated by combined-nitrogen deprivation, followed by the commitment step during which the developmental process becomes irreversible. Mature heterocysts are terminally differentiated cells unable to divide, and cell division is required for heterocyst differentiation. Previously, we have shown that the HetF protease regulates cell division and heterocyst differentiation by cleaving PatU3, which is an inhibitor for both events. When hetF is required during the developmental program remains unknown. Here, by controlling the timing of hetF expression during heterocyst differentiation, we provide evidence that hetF is required just before the beginning of heterocyst morphogenesis. Consistent with this finding, transcriptome data show that most of the genes known to be involved in the early step (such as hetR and ntcA) or the commitment step (such as hetP and hetZ) of heterocyst development could be expressed in the ΔhetF mutant. In contrast, most of the genes involved in heterocyst morphogenesis and nitrogen fixation remain repressed in the mutant. These results indicated that in the absence of hetF, heterocyst differentiation is able to be initiated and proceeds to the stage just before heterocyst envelope formation.
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Affiliation(s)
- Wei-Yue Xing
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China
| | - Jing Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China
| | - Cheng-Cai Zhang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, Hubei, People's Republic of China
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4
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Wanney WC, Youssar L, Kostova G, Georg J. Improved RNA stability estimation indicates that transcriptional interference is frequent in diverse bacteria. Commun Biol 2023; 6:732. [PMID: 37454177 PMCID: PMC10349824 DOI: 10.1038/s42003-023-05097-2] [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: 03/09/2023] [Accepted: 07/05/2023] [Indexed: 07/18/2023] Open
Abstract
We used stochastic simulations and experimental data from E. coli, K. aerogenes, Synechococcus PCC 7002 and Synechocystis PCC 6803 to provide evidence that transcriptional interference via the collision mechanism is likely a prevalent mechanism for bacterial gene regulation. Rifampicin time-series data can be used to globally monitor and quantify collision between sense and antisense transcription-complexes. Our findings also highlight that transcriptional events, such as differential RNA decay, partial termination, and internal transcriptional start sites often deviate from gene annotations. Consequently, within a single gene annotation, there exist transcript segments with varying half-lives and transcriptional properties. To address these complexities, we introduce 'rifi', an R-package that analyzes transcriptomic data from rifampicin time series. 'rifi' employs a dynamic programming-based segmentation approach to identify individual transcripts, enabling accurate assessment of RNA stability and detection of diverse transcriptional events.
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Affiliation(s)
- Walja C Wanney
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- Plant Biotechnology, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Loubna Youssar
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Gergana Kostova
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Jens Georg
- Genetics and Experimental Bioinformatics, Faculty of Biology, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany.
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Risser DD. Hormogonium Development and Motility in Filamentous Cyanobacteria. Appl Environ Microbiol 2023; 89:e0039223. [PMID: 37199640 PMCID: PMC10304961 DOI: 10.1128/aem.00392-23] [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: 05/19/2023] Open
Abstract
Filamentous cyanobacteria exhibit some of the greatest developmental complexity observed in the prokaryotic domain. This includes the ability to differentiate nitrogen-fixing cells known as heterocysts, spore-like akinetes, and hormogonia, which are specialized motile filaments capable of gliding on solid surfaces. Hormogonia and motility play critical roles in several aspects of the biology of filamentous cyanobacteria, including dispersal, phototaxis, the formation of supracellular structures, and the establishment of nitrogen-fixing symbioses with plants. While heterocyst development has been investigated extensively at the molecular level, much less is known about akinete or hormogonium development and motility. This is due, in part, to the loss of developmental complexity during prolonged laboratory culture in commonly employed model filamentous cyanobacteria. In this review, recent progress in understanding the molecular level regulation of hormogonium development and motility in filamentous cyanobacteria is discussed, with a focus on experiments performed using the genetically tractable model filamentous cyanobacterium Nostoc punctiforme, which retains the developmental complexity of field isolates.
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Affiliation(s)
- Douglas D. Risser
- Department of Biology, University of Colorado Colorado Springs, Colorado Springs, Colorado, USA
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Villa F, Ludwig N, Mazzini S, Scaglioni L, Fuchs AL, Tripet B, Copié V, Stewart PS, Cappitelli F. A desiccated dual-species subaerial biofilm reprograms its metabolism and affects water dynamics in limestone. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161666. [PMID: 36669662 DOI: 10.1016/j.scitotenv.2023.161666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Revised: 01/10/2023] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
Understanding the impact of sessile communities on underlying materials is of paramount importance in stone conservation. Up until now, the critical role of subaerial biofilms (SABs) whether they are protective or deteriorative remains unclear, especially under desiccation. The interest in desiccated SABs is raised by the prediction of an increase in drought events in the next decades that will affect the Mediterranean regions' rich stone heritage as never before. Thus, the main goal of this research is to study the effects of desiccation on both the biofilms' eco-physiology and its impacts on the lithic substrate. To this end, we used a dual-species model system composed of a phototroph and a chemotroph to simulate biofilm behavior on stone heritage. We found that drought altered the phototroph-chemotroph balance and enriched the biofilm matrix with proteins and DNA. Desiccated SABs underwent a shift in metabolism to fermentation and a decrease in oxidative stress. Additionally, desiccated SABs changed the water-related dynamics (adsorption, evaporation, and wetting properties) in limestone. Water absorption experiments showed that desiccated SABs protected the stone from rapid water uptake, while a thermographic survey indicated a delay in water evaporation. Spilling-drop tests revealed a change in the wettability of the stone-SAB interface, which affected the water transport properties of the stone. Finally, desiccated SABs reduced stone swelling in the presence of water vapor. The biodeteriorative and bioprotective implications of desiccated SABs on the stone were ultimately assessed.
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Affiliation(s)
- F Villa
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano, 20133 Milan, Italy.
| | - N Ludwig
- Dipartimento di Fisica Aldo Pontremoli, Università degli Studi di Milano, 20133 Milan, Italy.
| | - S Mazzini
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano, 20133 Milan, Italy.
| | - L Scaglioni
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano, 20133 Milan, Italy.
| | - A L Fuchs
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, USA
| | - B Tripet
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, USA.
| | - V Copié
- Department of Chemistry & Biochemistry, Montana State University, Bozeman, USA.
| | - P S Stewart
- Center for Biofilm Engineering, Montana State University, Bozeman 59717, USA.
| | - F Cappitelli
- Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano, 20133 Milan, Italy.
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Watanabe S, Stazic D, Georg J, Ohtake S, Sakamaki Y, Numakura M, Asayama M, Chibazakura T, Wilde A, Steglich C, Hess WR. Regulation of RNase E during the UV stress response in the cyanobacterium Synechocystis sp. PCC 6803. MLIFE 2023; 2:43-57. [PMID: 38818332 PMCID: PMC10989929 DOI: 10.1002/mlf2.12056] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 12/07/2022] [Accepted: 12/15/2022] [Indexed: 06/01/2024]
Abstract
Endoribonucleases govern the maturation and degradation of RNA and are indispensable in the posttranscriptional regulation of gene expression. A key endoribonuclease in Gram-negative bacteria is RNase E. To ensure an appropriate supply of RNase E, some bacteria, such as Escherichia coli, feedback-regulate RNase E expression via the rne 5'-untranslated region (5' UTR) in cis. However, the mechanisms involved in the control of RNase E in other bacteria largely remain unknown. Cyanobacteria rely on solar light as an energy source for photosynthesis, despite the inherent ultraviolet (UV) irradiation. In this study, we first investigated globally the changes in gene expression in the cyanobacterium Synechocystis sp. PCC 6803 after a brief exposure to UV. Among the 407 responding genes 2 h after UV exposure was a prominent upregulation of rne mRNA level. Moreover, the enzymatic activity of RNase E rapidly increased as well, although the protein stability decreased. This unique response was underpinned by the increased accumulation of full-length rne mRNA caused by the stabilization of its 5' UTR and suppression of premature transcriptional termination, but not by an increased transcription rate. Mapping of RNA 3' ends and in vitro cleavage assays revealed that RNase E cleaves within a stretch of six consecutive uridine residues within the rne 5' UTR, indicating autoregulation. These observations suggest that RNase E in cyanobacteria contributes to reshaping the transcriptome during the UV stress response and that its required activity level is secured at the RNA level despite the enhanced turnover of the protein.
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Affiliation(s)
- Satoru Watanabe
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Damir Stazic
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
- Present address:
NexxiotPrime Tower (Hardstrasse 201)ZurichSwitzerland
| | - Jens Georg
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
| | - Shota Ohtake
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Yutaka Sakamaki
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Megumi Numakura
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Munehiko Asayama
- School of Agriculture, Molecular GeneticsIbaraki UniversityIbarakiJapan
| | - Taku Chibazakura
- Faculty of Biology, Genetics and Experimental BioinformaticsUniversity of FreiburgFreiburgGermany
| | - Annegret Wilde
- Faculty of Biology, Molecular GeneticsUniversity of FreiburgFreiburgGermany
| | - Claudia Steglich
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
| | - Wolfgang R. Hess
- Department of BioscienceTokyo University of AgricultureSetagaya‐kuTokyoJapan
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8
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Kaltenbrunner A, Reimann V, Hoffmann UA, Aoyagi T, Sakata M, Nimura-Matsune K, Watanabe S, Steglich C, Wilde A, Hess WR. Regulation of pSYSA defense plasmid copy number in Synechocystis through RNase E and a highly transcribed asRNA. Front Microbiol 2023; 14:1112307. [PMID: 36876071 PMCID: PMC9978351 DOI: 10.3389/fmicb.2023.1112307] [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: 11/30/2022] [Accepted: 01/23/2023] [Indexed: 02/18/2023] Open
Abstract
Synthetic biology approaches toward the development of cyanobacterial producer strains require the availability of appropriate sets of plasmid vectors. A factor for the industrial usefulness of such strains is their robustness against pathogens, such as bacteriophages infecting cyanobacteria. Therefore, it is of great interest to understand the native plasmid replication systems and the CRISPR-Cas based defense mechanisms already present in cyanobacteria. In the model cyanobacterium Synechocystis sp. PCC 6803, four large and three smaller plasmids exist. The ~100 kb plasmid pSYSA is specialized in defense functions by encoding all three CRISPR-Cas systems and several toxin-antitoxin systems. The expression of genes located on pSYSA depends on the plasmid copy number in the cell. The pSYSA copy number is positively correlated with the expression level of the endoribonuclease E. As molecular basis for this correlation we identified the RNase E-mediated cleavage within the pSYSA-encoded ssr7036 transcript. Together with a cis-encoded abundant antisense RNA (asRNA1), this mechanism resembles the control of ColE1-type plasmid replication by two overlapping RNAs, RNA I and II. In the ColE1 mechanism, two non-coding RNAs interact, supported by the small protein Rop, which is encoded separately. In contrast, in pSYSA the similar-sized protein Ssr7036 is encoded within one of the interacting RNAs and it is this mRNA that likely primes pSYSA replication. Essential for plasmid replication is furthermore the downstream encoded protein Slr7037 featuring primase and helicase domains. Deletion of slr7037 led to the integration of pSYSA into the chromosome or the other large plasmid pSYSX. Moreover, the presence of slr7037 was required for successful replication of a pSYSA-derived vector in another model cyanobacterium, Synechococcus elongatus PCC 7942. Therefore, we annotated the protein encoded by slr7037 as Cyanobacterial Rep protein A1 (CyRepA1). Our findings open new perspectives on the development of shuttle vectors for genetic engineering of cyanobacteria and of modulating the activity of the entire CRISPR-Cas apparatus in Synechocystis sp. PCC 6803.
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Affiliation(s)
- Alena Kaltenbrunner
- Genetics and Experimental Bioinformatics Group, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Viktoria Reimann
- Genetics and Experimental Bioinformatics Group, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ute A Hoffmann
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Tomohiro Aoyagi
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | - Minori Sakata
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | | | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, Tokyo, Japan
| | - Claudia Steglich
- Genetics and Experimental Bioinformatics Group, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Annegret Wilde
- Molecular Genetics of Prokaryotes, Institute of Biology III, University of Freiburg, Freiburg, Germany
| | - Wolfgang R Hess
- Genetics and Experimental Bioinformatics Group, Faculty of Biology, University of Freiburg, Freiburg, Germany
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