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An extended catalogue of ncRNAs in Streptomyces coelicolor reporting abundant tmRNA, RNase-P RNA and RNA fragments derived from pre-ribosomal RNA leader sequences. Arch Microbiol 2022; 204:582. [PMID: 36042049 DOI: 10.1007/s00203-022-03203-2] [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: 06/09/2022] [Revised: 08/05/2022] [Accepted: 08/18/2022] [Indexed: 11/02/2022]
Abstract
Streptomyces coelicolor is a model organism for studying streptomycetes. This genus possesses relevant medical and economical roles, because it produces many biologically active metabolites of pharmaceutical interest, including the majority of commercialized antibiotics. In this bioinformatic study, the transcriptome of S. coelicolor has been analyzed to identify novel RNA species and quantify the expression of both annotated and novel transcripts in solid and liquid growth medium cultures at different times. The major characteristics disclosed in this study are: (i) the diffuse antisense transcription; (ii) the great abundance of transfer-messenger RNAs (tmRNA); (iii) the abundance of rnpB transcripts, paramount for the RNase-P complex; and (iv) the presence of abundant fragments derived from pre-ribosomal RNA leader sequences of unknown biological function. Overall, this study extends the catalogue of ncRNAs in S. coelicolor and suggests an important role of non-coding transcription in the regulation of biologically active molecule production.
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Campos-Silva R, D’Urso G, Delalande O, Giudice E, Macedo AJ, Gillet R. Trans-Translation Is an Appealing Target for the Development of New Antimicrobial Compounds. Microorganisms 2021; 10:3. [PMID: 35056452 PMCID: PMC8778911 DOI: 10.3390/microorganisms10010003] [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: 11/24/2021] [Revised: 12/09/2021] [Accepted: 12/16/2021] [Indexed: 01/06/2023] Open
Abstract
Because of the ever-increasing multidrug resistance in microorganisms, it is crucial that we find and develop new antibiotics, especially molecules with different targets and mechanisms of action than those of the antibiotics in use today. Translation is a fundamental process that uses a large portion of the cell's energy, and the ribosome is already the target of more than half of the antibiotics in clinical use. However, this process is highly regulated, and its quality control machinery is actively studied as a possible target for new inhibitors. In bacteria, ribosomal stalling is a frequent event that jeopardizes bacterial wellness, and the most severe form occurs when ribosomes stall at the 3'-end of mRNA molecules devoid of a stop codon. Trans-translation is the principal and most sophisticated quality control mechanism for solving this problem, which would otherwise result in inefficient or even toxic protein synthesis. It is based on the complex made by tmRNA and SmpB, and because trans-translation is absent in eukaryotes, but necessary for bacterial fitness or survival, it is an exciting and realistic target for new antibiotics. Here, we describe the current and future prospects for developing what we hope will be a novel generation of trans-translation inhibitors.
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Affiliation(s)
- Rodrigo Campos-Silva
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90610-000, Brazil;
| | - Gaetano D’Urso
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
| | - Olivier Delalande
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
| | - Emmanuel Giudice
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
| | - Alexandre José Macedo
- Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia and Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90610-000, Brazil;
| | - Reynald Gillet
- CNRS, Institut de Génétique et Développement de Rennes (IGDR) UMR6290, University of Rennes, 35000 Rennes, France; (R.C.-S.); (G.D.); (O.D.); (E.G.)
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Zhang Y, Liu Z, Tang Y, Ma X, Tang H, Li H, Liu Z. Cbl upregulates cysH for hydrogen sulfide production in Aeromonas veronii. PeerJ 2021; 9:e12058. [PMID: 34589297 PMCID: PMC8435198 DOI: 10.7717/peerj.12058] [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: 03/30/2021] [Accepted: 08/04/2021] [Indexed: 11/20/2022] Open
Abstract
Endogenous hydrogen sulfide (H2S) is generated in many metabolism pathways, and has been recognized as a second messenger against antibiotics and reactive oxygen species (ROS). In Aeromonas veronii, Small Protein B (SmpB) plays an important role in resisting stress. The absence of smpB could trigger sulfate assimilation pathway to adapt the nutrient deficiency, of which was mediated by up-regulation of cbl and cys genes and followed with enhancing H2S production. To figure out the mutual regulations of cbl and cys genes, a series of experiments were performed. Compared with the wild type, cysH was down-regulated significantly in cbl deletion by qRT-PCR. The fluorescence analysis further manifested that Cbl had a positive regulatory effect on the promoter of cysJIH. Bacterial one-hybrid analysis and electrophoretic mobility shift assay (EMSA) verified that Cbl bound with the promoter of cysJIH. Collectively, the tolerance to adversity could be maintained by the production of H2S when SmpB was malfunctioned, of which the activity of cysJIH promoter was positively regulated by upstream Cbl protein. The outcomes also suggested the enormous potentials of Aeromonas veronii in environmental adaptability.
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Affiliation(s)
| | | | | | - Xiang Ma
- Hainan University, Haikou, China
| | | | - Hong Li
- Hainan University, Haikou, China
| | - Zhu Liu
- Hainan University, Haikou, China
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Genetic analysis of Streptomyces albus J1074 mia mutants suggests complex relationships between post-transcriptional tRNA XXA modifications and physiological traits. Folia Microbiol (Praha) 2020; 65:1009-1015. [PMID: 32676973 DOI: 10.1007/s12223-020-00811-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/08/2020] [Indexed: 10/23/2022]
Abstract
Proteins MiaA and MiaB catalyze sequential isopentenylation and methylthiolation, respectively, of adenosine residue in 37th position of tRNAXXA. The mia mutations were recently shown by us to affect secondary metabolism and morphology of Streptomyces. However, it remained unknown as to whether both or one of the aforementioned modifications is critical for colony development and antibiotic production. Here, we addressed this issue through analysis of Streptomyces albus J1074 strains carrying double miaAmiaB knockout or extra copy of miaB gene. The double mutant differed from wild-type and miaA-minus strains in severity of morphological defects, growth dynamics, and secondary metabolism. Introduction of extra copy of miaB gene into miaA mutant restored aerial mycelium formation to the latter on certain solid media. Hence, miaB gene might be involved in tRNA thiomethylation in the absence of miaA; either MiaA- or MiaB-mediated modification appears to be enough to support normal metabolic and morphological processes in Streptomyces.
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Peng M, Cao X, Tang Y, Li H, Ma X, Liu Z. Large-scale identification of trans-translation substrates targeted by tmRNA in Aeromonas veronii. Microb Pathog 2020; 145:104226. [PMID: 32353577 DOI: 10.1016/j.micpath.2020.104226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/18/2020] [Accepted: 04/20/2020] [Indexed: 10/24/2022]
Abstract
Transfer-messenger RNA (tmRNA) is ubiquitous in bacteria, acting as the core component for the trans-translation system that contributes to label the aberrantly synthesized peptides for degradation and to release the stalled ribosomes. Deletion of tmRNA causes a variety of phenotypes related to important physiological processes in bacteria. To illustrate the molecular mechanism of the versatility of tmRNA in aquatic pathogen Aeromonas veronii, we mutated the C-terminal nucleotides of tmRNA (MutmRNA) for encoding a tag containing six histidine residues (His6tag), so as to capture and enrich the trans-translation substrates from the cell lysates through a Ni2+-NTA affinity chromatograph. The results showed that the concentrated substrates were detected as distinct and specific bands in western blotting using anti-His antibody, demonstrating that specific defective mRNAs were frequently and intensively rescued by trans-translation during the translation process in A. veronii. The substrates were analyzed by LC-MS/MS and further identified by searching a theoretically constructed database specific for A. veronii. Total of 24 potential substrates were identified, with various functions involved in metabolism, as well as structure and signal-based cellular events. Among the identified substrates, PspA and AsmA were labeled by Flag, and expressed in the presence of the modified trans-translation system in E. coli. Their labelings with MutmRNA were validated by purification through Ni2+-NTA column followed by western blotting using anti-Flag antibody. This study provided the most abundant set of endogenous targets for tmRNA in A. veronii, and facilitated further investigations about the molecular mechanism and signal pathway of tmRNA-mediated trans-translation.
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Affiliation(s)
- Muzhi Peng
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, 570228, Haikou, China
| | - Xin Cao
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, 570228, Haikou, China
| | - Yanqiong Tang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, 570228, Haikou, China
| | - Hong Li
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, 570228, Haikou, China
| | - Xiang Ma
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, 570228, Haikou, China.
| | - Zhu Liu
- Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Life and Pharmaceutical Sciences, Hainan University, 570228, Haikou, China.
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Vollmer AC, Bark SJ. Twenty-Five Years of Investigating the Universal Stress Protein: Function, Structure, and Applications. ADVANCES IN APPLIED MICROBIOLOGY 2017; 102:1-36. [PMID: 29680123 DOI: 10.1016/bs.aambs.2017.10.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Since the initial discovery of universal stress protein A (UspA) 25 years ago, remarkable advances in molecular and biochemical technologies have revolutionized our understanding of biology. Many studies using these technologies have focused on characterization of the uspA gene and Usp-type proteins. These studies have identified the conservation of Usp-like proteins across bacteria, archaea, plants, and even some invertebrate animals. Regulation of these proteins under diverse stresses has been associated with different stress-response genes including spoT and relA in the stringent response and the dosR two-component signaling pathways. These and other foundational studies suggest Usps serve regulatory and protective roles to enable adaptation and survival under external stresses. Despite these foundational studies, many bacterial species have multiple paralogs of genes encoding these proteins and ablation of the genes does not provide a distinct phenotype. This outcome has limited our understanding of the biochemical functions of these proteins. Here, we summarize the current knowledge of Usps in general and UspA in particular across different genera as well as conclusions about their functions from seminal studies in diverse organisms. Our objective has been to organize the foundational studies in this field to identify the significant impediments to further understanding of Usp functions at the molecular level. We propose ideas and experimental approaches that may overcome these impediments and drive future development of molecular approaches to understand and target Usps as central regulators of stress adaptation and survival. Despite the fact that the full functions of Usps are still not known, creative many applications have already been proposed, tested, and used. The complementary approaches of basic research and applications, along with new technology and analytic tools, may yield the elusive yet critical functions of universal stress proteins in diverse systems.
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van der Meij A, Worsley SF, Hutchings MI, van Wezel GP. Chemical ecology of antibiotic production by actinomycetes. FEMS Microbiol Rev 2017; 41:392-416. [DOI: 10.1093/femsre/fux005] [Citation(s) in RCA: 220] [Impact Index Per Article: 31.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/02/2017] [Indexed: 12/13/2022] Open
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Brito L, Wilton J, Ferrándiz MJ, Gómez-Sanz A, de la Campa AG, Amblar M. Absence of tmRNA Has a Protective Effect against Fluoroquinolones in Streptococcus pneumoniae. Front Microbiol 2017; 7:2164. [PMID: 28119681 PMCID: PMC5222879 DOI: 10.3389/fmicb.2016.02164] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 12/23/2016] [Indexed: 11/13/2022] Open
Abstract
The transfer messenger RNA (tmRNA), encoded by the ssrA gene, is a small non-coding RNA involved in trans-translation that contributes to the recycling of ribosomes stalled on aberrant mRNAs. In most bacteria, its inactivation has been related to a decreased ability to respond to and recover from a variety of stress conditions. In this report, we investigated the role of tmRNA in stress adaptation in the human pathogen Streptococcus pneumoniae. We constructed a tmRNA deletion mutant and analyzed its response to several lethal stresses. The ΔssrA strain grew slower than the wild type, indicating that, although not essential, tmRNA is important for normal pneumococcal growth. Moreover, deletion of tmRNA increased susceptibility to UV irradiation, to exogenous hydrogen peroxide and to antibiotics that inhibit protein synthesis and transcription. However, the ΔssrA strain was more resistant to fluoroquinolones, showing twofold higher MIC values and up to 1000-fold higher survival rates than the wild type. Deletion of SmpB, the other partner in trans-translation, also reduced survival to levofloxacin in a similar extent. Accumulation of intracellular reactive oxygen species associated to moxifloxacin and levofloxacin treatment was also highly reduced (∼100-fold). Nevertheless, the ΔssrA strain showed higher intracellular accumulation of ethidium bromide and levofloxacin than the wild type, suggesting that tmRNA deficiency protects pneumococcal cells from fluoroquinolone-mediated killing. In fact, analysis of chromosome integrity revealed that deletion of tmRNA prevented the fragmentation of the chromosome associated to levofloxacin treatment. Moreover, such protective effect appears to relay mainly on inhibition of protein synthesis, since a similar effect was observed with antibiotics that inhibit that process. The emergence and spread of drug-resistant pneumococci is a matter of concern and these results contribute to a better comprehension of the mechanisms underlying fluoroquinolones action.
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Affiliation(s)
- Liliana Brito
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Joana Wilton
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - María J Ferrándiz
- Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Alicia Gómez-Sanz
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
| | - Adela G de la Campa
- Unidad de Genética Bacteriana, Centro Nacional de Microbiología, Instituto de Salud Carlos IIIMadrid, Spain; Presidencia, Consejo Superior de Investigaciones CientíficasMadrid, Spain
| | - Mónica Amblar
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Madrid, Spain
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10
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Domingues S, Moreira RN, Andrade JM, Dos Santos RF, Bárria C, Viegas SC, Arraiano CM. The role of RNase R in trans-translation and ribosomal quality control. Biochimie 2014; 114:113-8. [PMID: 25542646 DOI: 10.1016/j.biochi.2014.12.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 12/18/2014] [Indexed: 01/11/2023]
Abstract
Gene expression not only depends on the rate of transcription but is also largely controlled at the post-transcriptional level. Translation rate and mRNA decay greatly influence the final protein levels. Surveillance mechanisms are essential to ensure the quality of the RNA and proteins produced. Trans-translation is one of the most important systems in the quality control of bacterial translation. This process guarantees the destruction of abnormal proteins and also leads to degradation of the respective defective RNAs through the action of Ribonuclease R (RNase R). This exoribonuclease hydrolyzes RNAs starting from their 3' end. Besides its involvement in trans-translation, RNase R also participates in the quality control of rRNA molecules involved in ribosomal biogenesis. RNase R is thus emerging as a key factor in ensuring translation accuracy. This review focuses on issues related to the quality control of translation, with special emphasis on the role of RNase R.
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Affiliation(s)
- Susana Domingues
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Ricardo N Moreira
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - José M Andrade
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Ricardo F Dos Santos
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Cátia Bárria
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Sandra C Viegas
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal.
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Himeno H, Kurita D, Muto A. tmRNA-mediated trans-translation as the major ribosome rescue system in a bacterial cell. Front Genet 2014; 5:66. [PMID: 24778639 PMCID: PMC3985003 DOI: 10.3389/fgene.2014.00066] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 03/15/2014] [Indexed: 11/13/2022] Open
Abstract
Transfer messenger RNA (tmRNA; also known as 10Sa RNA or SsrA RNA) is a small RNA molecule that is conserved among bacteria. It has structural and functional similarities to tRNA: it has an upper half of the tRNA-like structure, its 5’ end is processed by RNase P, it has typical tRNA-specific base modifications, it is aminoacylated with alanine, it binds to EF-Tu after aminoacylation and it enters the ribosome with EF-Tu and GTP. However, tmRNA lacks an anticodon, and instead it has a coding sequence for a short peptide called tag-peptide. An elaborate interplay of actions of tmRNA as both tRNA and mRNA with the help of a tmRNA-binding protein, SmpB, facilitates trans-translation, which produces a single polypeptide from two mRNA molecules. Initially alanyl-tmRNA in complex with EF-Tu and SmpB enters the vacant A-site of the stalled ribosome like aminoacyl-tRNA but without a codon–anticodon interaction, and subsequently truncated mRNA is replaced with the tag-encoding region of tmRNA. During these processes, not only tmRNA but also SmpB structurally and functionally mimics both tRNA and mRNA. Thus trans-translation rescues the stalled ribosome, thereby allowing recycling of the ribosome. Since the tag-peptide serves as a target of AAA+ proteases, the trans-translation products are preferentially degraded so that they do not accumulate in the cell. Although alternative rescue systems have recently been revealed, trans-translation is the only system that universally exists in bacteria. Furthermore, it is unique in that it employs a small RNA and that it prevents accumulation of non-functional proteins from truncated mRNA in the cell. It might play the major role in rescuing the stalled translation in the bacterial cell.
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Affiliation(s)
- Hyouta Himeno
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University Hirosaki, Japan
| | - Daisuke Kurita
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University Hirosaki, Japan
| | - Akira Muto
- Department of Biochemistry and Molecular Biology, Faculty of Agriculture and Life Science, Hirosaki University Hirosaki, Japan
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Venkataramanan KP, Jones SW, McCormick KP, Kunjeti SG, Ralston MT, Meyers BC, Papoutsakis ET. The Clostridium small RNome that responds to stress: the paradigm and importance of toxic metabolite stress in C. acetobutylicum. BMC Genomics 2013; 14:849. [PMID: 24299206 PMCID: PMC3879012 DOI: 10.1186/1471-2164-14-849] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Accepted: 11/14/2013] [Indexed: 01/01/2023] Open
Abstract
Background Small non-coding RNAs (sRNA) are emerging as major components of the cell’s regulatory network, several possessing their own regulons. A few sRNAs have been reported as being involved in general or toxic-metabolite stress, mostly in Gram- prokaryotes, but hardly any in Gram+ prokaryotes. Significantly, the role of sRNAs in the stress response remains poorly understood at the genome-scale level. It was previously shown that toxic-metabolite stress is one of the most comprehensive and encompassing stress responses in the cell, engaging both the general stress (or heat-shock protein, HSP) response as well as specialized metabolic programs. Results Using RNA deep sequencing (RNA-seq) we examined the sRNome of C. acetobutylicum in response to the native but toxic metabolites, butanol and butyrate. 7.5% of the RNA-seq reads mapped to genome outside annotated ORFs, thus demonstrating the richness and importance of the small RNome. We used comparative expression analysis of 113 sRNAs we had previously computationally predicted, and of annotated mRNAs to set metrics for reliably identifying sRNAs from RNA-seq data, thus discovering 46 additional sRNAs. Under metabolite stress, these 159 sRNAs displayed distinct expression patterns, a select number of which was verified by Northern analysis. We identified stress-related expression of sRNAs affecting transcriptional (6S, S-box & solB) and translational (tmRNA & SRP-RNA) processes, and 65 likely targets of the RNA chaperone Hfq. Conclusions Our results support an important role for sRNAs for understanding the complexity of the regulatory network that underlies the stress response in Clostridium organisms, whether related to normophysiology, pathogenesis or biotechnological applications.
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Gubbens J, Janus MM, Florea BI, Overkleeft HS, van Wezel GP. Identification of glucose kinase-dependent and -independent pathways for carbon control of primary metabolism, development and antibiotic production in Streptomyces coelicolor by quantitative proteomics. Mol Microbiol 2012; 86:1490-507. [PMID: 23078239 DOI: 10.1111/mmi.12072] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2012] [Indexed: 11/30/2022]
Abstract
Members of the soil-dwelling prokaryotic genus Streptomyces are indispensable for the recycling of complex polysaccharides, and produce a wide range of natural products. Nutrient availability is a major determinant for the switch to development and antibiotic production in streptomycetes. Carbon catabolite repression (CCR), a main signalling pathway underlying this phenomenon, was so far considered fully dependent on the glycolytic enzyme glucose kinase (Glk). Here we provide evidence of a novel Glk-independent pathway in Streptomyces coelicolor, using advanced proteomics that allowed the comparison of the expression of some 2000 proteins, including virtually all enzymes for central metabolism. While CCR and inducer exclusion of enzymes for primary and secondary metabolism and precursor supply for natural products is mostly mediated via Glk, enzymes for the urea cycle, as well as for biosynthesis of the γ-butyrolactone Scb1 and the responsive cryptic polyketide Cpk are subject to Glk-independent CCR. Deletion of glkA led to strong downregulation of biosynthetic proteins for prodigionins and calcium-dependent antibiotic (CDA) in mannitol-grown cultures. Repression of bldB, bldN, and its target bldM may explain the poor development of S. coelicolor on solid-grown cultures containing glucose. A new model for carbon catabolite repression in streptomycetes is presented.
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Affiliation(s)
- Jacob Gubbens
- Leiden Institute of Chemistry, Leiden University, PO Box 9502, 2300RA, Leiden, The Netherlands
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Kim MS, Dufour YS, Yoo JS, Cho YB, Park JH, Nam GB, Kim HM, Lee KL, Donohue TJ, Roe JH. Conservation of thiol-oxidative stress responses regulated by SigR orthologues in actinomycetes. Mol Microbiol 2012; 85:326-44. [PMID: 22651816 DOI: 10.1111/j.1365-2958.2012.08115.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Numerous thiol-reactive compounds cause oxidative stress where cells counteract by activation of survival strategies regulated by thiol-based sensors. In Streptomyces coelicolor, a model actinomycete, a sigma/antisigma pair SigR/RsrA controls the response to thiol-oxidative stress. To unravel its full physiological functions, chromatin immuno-precipitation combined with sequence and transcript analyses were employed to identify 108 SigR target genes in S. coelicolor and to predict orthologous regulons across actinomycetes. In addition to reported genes for thiol homeostasis, protein degradation and ribosome modulation, 64 additional operons were identified suggesting new functions of this global regulator. We demonstrate that SigR maintains the level and activity of the housekeeping sigma factor HrdB during thiol-oxidative stress, a novel strategy for stress responses. We also found that SigR defends cells against UV and thiol-reactive damages, in which repair UvrA takes a part. Using a refined SigR-binding sequence model, SigR orthologues and their targets were predicted in 42 actinomycetes. This revealed a conserved core set of SigR targets to function for thiol homeostasis, protein quality control, possible modulation of transcription and translation, flavin-mediated redox reactions, and Fe-S delivery. The composition of the SigR regulon reveals a robust conserved physiological mechanism to deal with thiol-oxidative stress from bacteria to human.
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Affiliation(s)
- Min-Sik Kim
- Laboratory of Molecular Microbiology, School of Biological Sciences, and Institute of Microbiology, Seoul National University, Seoul 151-742, Korea
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Janssen BD, Hayes CS. The tmRNA ribosome-rescue system. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 86:151-91. [PMID: 22243584 DOI: 10.1016/b978-0-12-386497-0.00005-0] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The bacterial tmRNA quality control system monitors protein synthesis and recycles stalled translation complexes in a process termed "ribosome rescue." During rescue, tmRNA acts first as a transfer RNA to bind stalled ribosomes, then as a messenger RNA to add the ssrA peptide tag to the C-terminus of the nascent polypeptide chain. The ssrA peptide targets tagged peptides for proteolysis, ensuring rapid degradation of potentially deleterious truncated polypeptides. Ribosome rescue also facilitates turnover of the damaged messages responsible for translational arrest. Thus, tmRNA increases the fidelity of gene expression by promoting the synthesis of full-length proteins. In addition to serving as a global quality control system, tmRNA also plays important roles in bacterial development, pathogenesis, and environmental stress responses. This review focuses on the mechanism of tmRNA-mediated ribosome rescue and the role of tmRNA in bacterial physiology.
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Affiliation(s)
- Brian D Janssen
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California, USA
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A novel function of Streptomyces integration host factor (sIHF) in the control of antibiotic production and sporulation in Streptomyces coelicolor. Antonie van Leeuwenhoek 2011; 101:479-92. [DOI: 10.1007/s10482-011-9657-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 10/11/2011] [Indexed: 10/15/2022]
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van Wezel GP, McDowall KJ. The regulation of the secondary metabolism of Streptomyces: new links and experimental advances. Nat Prod Rep 2011; 28:1311-33. [PMID: 21611665 DOI: 10.1039/c1np00003a] [Citation(s) in RCA: 315] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Streptomycetes and other actinobacteria are renowned as a rich source of natural products of clinical, agricultural and biotechnological value. They are being mined with renewed vigour, supported by genome sequencing efforts, which have revealed a coding capacity for secondary metabolites in vast excess of expectations that were based on the detection of antibiotic activities under standard laboratory conditions. Here we review what is known about the control of production of so-called secondary metabolites in streptomycetes, with an emphasis on examples where details of the underlying regulatory mechanisms are known. Intriguing links between nutritional regulators, primary and secondary metabolism and morphological development are discussed, and new data are included on the carbon control of development and antibiotic production, and on aspects of the regulation of the biosynthesis of microbial hormones. Given the tide of antibiotic resistance emerging in pathogens, this review is peppered with approaches that may expand the screening of streptomycetes for new antibiotics by awakening expression of cryptic antibiotic biosynthetic genes. New technologies are also described that have potential to greatly further our understanding of gene regulation in what is an area fertile for discovery and exploitation
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Barends S, Kraal B, van Wezel GP. The tmRNA-tagging mechanism and the control of gene expression: a review. WILEY INTERDISCIPLINARY REVIEWS-RNA 2010; 2:233-46. [PMID: 21957008 DOI: 10.1002/wrna.48] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The tmRNA-mediated trans-translation system is a unique quality control system in eubacteria that combines translational surveillance with the rescue of stalled ribosomes. During trans-translation, the chimeric tmRNA molecule--which acts as both tRNA and mRNA--is delivered to the ribosomal A site by a ribonucleoprotein complex of SmpB and EF-Tu-GTP, allowing the stalled ribosome to switch template and resume translation on a small coding sequence inside the tmRNA molecule. As a result, the aberrant protein becomes tagged by a sequence that is a target for proteolytic degradation. Thus, the system elegantly combines ribosome recycling with a clean-up function when triggered by truncated transcripts or rare codons. In addition, recent observations point to a specific regulation of the translation of a small number of genes by tmRNA-mediated inhibition or stimulation. In this review, we discuss the most prominent biochemical and structural aspects of trans-translation and then focus on the specific role of tmRNA in stress management and cell-cycle control of morphologically complex bacteria.
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Affiliation(s)
- Sharief Barends
- ProteoNic, Niels Bohrweg 11-13, 2333 CA Leiden, The Netherlands
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19
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Kallifidas D, Thomas D, Doughty P, Paget MSB. The sigmaR regulon of Streptomyces coelicolor A32 reveals a key role in protein quality control during disulphide stress. MICROBIOLOGY-SGM 2010; 156:1661-1672. [PMID: 20185507 DOI: 10.1099/mic.0.037804-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Diamide is an artificial disulphide-generating electrophile that mimics an oxidative shift in the cellular thiol-disulphide redox state (disulphide stress). The Gram-positive bacterium Streptomyces coelicolor senses and responds to disulphide stress through the sigma(R)-RsrA system, which comprises an extracytoplasmic function (ECF) sigma factor and a redox-active anti-sigma factor. Known targets that aid in the protection and recovery from disulphide stress include the thioredoxin system and genes involved in producing the major thiol buffer mycothiol. Here we determine the global response to diamide in wild-type and sigR mutant backgrounds to understand the role of sigma(R) in this response and to reveal additional regulatory pathways that allow cells to cope with disulphide stress. In addition to thiol oxidation, diamide was found to cause protein misfolding and aggregation, which elicited the induction of the HspR heat-shock regulon. Although this response is sigma(R)-independent, sigma(R) does directly control Clp and Lon ATP-dependent AAA(+) proteases, which may partly explain the reduced ability of a sigR mutant to resolubilize protein aggregates. sigma(R) also controls msrA and msrB methionine sulphoxide reductase genes, implying that sigma(R)-RsrA is responsible for the maintenance of both cysteine and methionine residues during oxidative stress. This work shows that the sigma(R)-RsrA system plays a more significant role in protein quality control than previously realized, and emphasizes the importance of controlling the cellular thiol-disulphide redox balance.
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Affiliation(s)
- Dimitris Kallifidas
- Department of Chemistry and Biochemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Derek Thomas
- Department of Chemistry and Biochemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Phillip Doughty
- Department of Chemistry and Biochemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
| | - Mark S B Paget
- Department of Chemistry and Biochemistry, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QG, UK
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