51
|
Jones SP, Goossen C, Lewis SD, Delaney AM, Gleghorn ML. Not making the cut: Techniques to prevent RNA cleavage in structural studies of RNase-RNA complexes. J Struct Biol X 2022; 6:100066. [PMID: 35340590 PMCID: PMC8943300 DOI: 10.1016/j.yjsbx.2022.100066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/04/2022] [Indexed: 11/16/2022] Open
Abstract
RNases are varied in the RNA structures and sequences they target for cleavage and are an important type of enzyme in cells. Despite the numerous examples of RNases known, and of those with determined three-dimensional structures, relatively few examples exist with the RNase bound to intact cognate RNA substrate prior to cleavage. To better understand RNase structure and sequence specificity for RNA targets, in vitro methods used to assemble these enzyme complexes trapped in a pre-cleaved state have been developed for a number of different RNases. We have surveyed the Protein Data Bank for such structures and in this review detail methodologies that have successfully been used and relate them to the corresponding structures. We also offer ideas and suggestions for future method development. Many strategies within this review can be used in combination with X-ray crystallography, as well as cryo-EM, and other structure-solving techniques. Our hope is that this review will be used as a guide to resolve future yet-to-be-determined RNase-substrate complex structures.
Collapse
Affiliation(s)
- Seth P. Jones
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
| | - Christian Goossen
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
- Pittsburgh Heart, Lung, Blood and Vascular Medicine Institute, University of Pittsburgh, Lothrop St, Pittsburgh, PA 15261, United States
| | - Sean D. Lewis
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
- Mayo Clinic, 200 1st St SW, Rochester, MN 5590, United States
| | - Annie M. Delaney
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
| | - Michael L. Gleghorn
- School of Chemistry and Materials Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623-5603, United States
| |
Collapse
|
52
|
Garcia Gonzalez J, Hernandez FJ. Nuclease activity: an exploitable biomarker in bacterial infections. Expert Rev Mol Diagn 2022; 22:265-294. [PMID: 35240900 DOI: 10.1080/14737159.2022.2049249] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION In the increasingly challenging field of clinical microbiology, diagnosis is a cornerstone whose accuracy and timing are crucial for the successful management, therapy, and outcome of infectious diseases. Currently employed biomarkers of infectious diseases define the scope and limitations of diagnostic techniques. As such, expanding the biomarker catalog is crucial to address unmet needs and bring about novel diagnostic functionalities and applications. AREAS COVERED This review describes the extracellular nucleases of 15 relevant bacterial pathogens and discusses the potential use of nuclease activity as a diagnostic biomarker. Articles were searched for in PubMed using terms: "nuclease", "bacteria", "nuclease activity" or "biomarker". For overview sections, original and review articles between 2000 and 2019 were searched for using terms: "infections", "diagnosis", "bacterial", "burden", "challenges". Informative articles were selected. EXPERT OPINION Using the catalytic activity of nucleases offers new possibilities compared to established biomarkers. Nucleic acid activatable reporters in combination with different transduction platforms and delivery methods can be used to detect disease-associated nuclease activity patterns in vitro and in vivo for prognostic and diagnostic applications. Even when these patterns are not obvious or of unknown etiology, screening platforms could be used to identify new disease reporters.
Collapse
Affiliation(s)
- Javier Garcia Gonzalez
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.,Wallenberg Centre for Molecular Medicine (WCMM), Linköping, Sweden.,Nucleic Acids Technologies Laboratory (NAT-lab), Linköping University, Linköping, Sweden
| | - Frank J Hernandez
- Department of Physics, Chemistry and Biology, Linköping University, Linköping, Sweden.,Wallenberg Centre for Molecular Medicine (WCMM), Linköping, Sweden.,Nucleic Acids Technologies Laboratory (NAT-lab), Linköping University, Linköping, Sweden
| |
Collapse
|
53
|
Zhang J, Hess WR, Zhang C. "Life is short, and art is long": RNA degradation in cyanobacteria and model bacteria. MLIFE 2022; 1:21-39. [PMID: 38818322 PMCID: PMC10989914 DOI: 10.1002/mlf2.12015] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 06/01/2024]
Abstract
RNA turnover plays critical roles in the regulation of gene expression and allows cells to respond rapidly to environmental changes. In bacteria, the mechanisms of RNA turnover have been extensively studied in the models Escherichia coli and Bacillus subtilis, but not much is known in other bacteria. Cyanobacteria are a diverse group of photosynthetic organisms that have great potential for the sustainable production of valuable products using CO2 and solar energy. A better understanding of the regulation of RNA decay is important for both basic and applied studies of cyanobacteria. Genomic analysis shows that cyanobacteria have more than 10 ribonucleases and related proteins in common with E. coli and B. subtilis, and only a limited number of them have been experimentally investigated. In this review, we summarize the current knowledge about these RNA-turnover-related proteins in cyanobacteria. Although many of them are biochemically similar to their counterparts in E. coli and B. subtilis, they appear to have distinct cellular functions, suggesting a different mechanism of RNA turnover regulation in cyanobacteria. The identification of new players involved in the regulation of RNA turnover and the elucidation of their biological functions are among the future challenges in this field.
Collapse
Affiliation(s)
- Ju‐Yuan Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of HydrobiologyChinese Academy of SciencesWuhanChina
| | - Wolfgang R. Hess
- Genetics and Experimental Bioinformatics, Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Cheng‐Cai Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology and Key Laboratory of Algal Biology, Institute of HydrobiologyChinese Academy of SciencesWuhanChina
- Institut WUT‐AMUAix‐Marseille University and Wuhan University of TechnologyWuhanChina
| |
Collapse
|
54
|
Ulyanova V, Nadyrova A, Dudkina E, Kuznetsova A, Ahmetgalieva A, Faizullin D, Surchenko Y, Novopashina D, Zuev Y, Kuznetsov N, Ilinskaya O. Structural and Functional Differences between Homologous Bacterial Ribonucleases. Int J Mol Sci 2022; 23:ijms23031867. [PMID: 35163789 PMCID: PMC8837141 DOI: 10.3390/ijms23031867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Revised: 01/28/2022] [Accepted: 02/04/2022] [Indexed: 02/04/2023] Open
Abstract
Small cationic guanyl-preferring ribonucleases (RNases) produced by the Bacillus species share a similar protein tertiary structure with a high degree of amino acid sequence conservation. However, they form dimers that differ in conformation and stability. Here, we have addressed the issues (1) whether the homologous RNases also have distinctions in catalytic activity towards different RNA substrates and interactions with the inhibitor protein barstar, and (2) whether these differences correlate with structural features of the proteins. Circular dichroism and dynamic light scattering assays revealed distinctions in the structures of homologous RNases. The activity levels of the RNases towards natural RNA substrates, as measured spectrometrically by acid-soluble hydrolysis products, were similar and decreased in the row high-polymeric RNA >>> transport RNA > double-stranded RNA. However, stopped flow kinetic studies on model RNA substrates containing the guanosine residue in a hairpin stem or a loop showed that the cleavage rates of these enzymes were different. Moreover, homologous RNases were inhibited by the barstar with diverse efficiency. Therefore, minor changes in structure elements of homologous proteins have a potential to significantly effect molecule stability and functional activities, such as catalysis or ligand binding.
Collapse
Affiliation(s)
- Vera Ulyanova
- Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia; (A.N.); (E.D.); (A.A.); (Y.S.); (O.I.)
- Correspondence:
| | - Alsu Nadyrova
- Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia; (A.N.); (E.D.); (A.A.); (Y.S.); (O.I.)
| | - Elena Dudkina
- Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia; (A.N.); (E.D.); (A.A.); (Y.S.); (O.I.)
| | - Aleksandra Kuznetsova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.K.); (D.N.); (N.K.)
| | - Albina Ahmetgalieva
- Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia; (A.N.); (E.D.); (A.A.); (Y.S.); (O.I.)
| | - Dzhigangir Faizullin
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (D.F.); (Y.Z.)
| | - Yulia Surchenko
- Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia; (A.N.); (E.D.); (A.A.); (Y.S.); (O.I.)
| | - Darya Novopashina
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.K.); (D.N.); (N.K.)
| | - Yuriy Zuev
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, 420111 Kazan, Russia; (D.F.); (Y.Z.)
| | - Nikita Kuznetsov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (A.K.); (D.N.); (N.K.)
| | - Olga Ilinskaya
- Department of Microbiology, Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, 420008 Kazan, Russia; (A.N.); (E.D.); (A.A.); (Y.S.); (O.I.)
| |
Collapse
|
55
|
Abstract
Detailed studies of the Gram-negative model bacterium, Escherichia coli, have demonstrated that post-transcriptional events exert important and possibly greater control over gene regulation than transcription initiation or effective translation. Thus, over the past 30 years, considerable effort has been invested in understanding the pathways of mRNA turnover in E. coli. Although it is assumed that most of the ribonucleases and accessory proteins involved in mRNA decay have been identified, our understanding of the regulation of mRNA decay is still incomplete. Furthermore, the vast majority of the studies on mRNA decay have been conducted on exponentially growing cells. Thus, the mechanism of mRNA decay as currently outlined may not accurately reflect what happens when cells find themselves under a variety of stress conditions, such as, nutrient starvation, changes in pH and temperature, as well as a host of others. While the cellular machinery for degradation is relatively constant over a wide range of conditions, intracellular levels of specific ribonucleases can vary depending on the growth conditions. Substrate competition will also modulate ribonucleolytic activity. Post-transcriptional modifications of transcripts by polyadenylating enzymes may favor a specific ribonuclease activity. Interactions with small regulatory RNAs and RNA binding proteins add additional complexities to mRNA functionality and stability. Since many of the ribonucleases are found at the inner membrane, the physical location of a transcript may help determine its half-life. Here we discuss the properties and role of the enzymes involved in mRNA decay as well as the multiple factors that may affect mRNA decay under various in vivo conditions.
Collapse
Affiliation(s)
| | - Sidney R. Kushner
- Department of Genetics, University of Georgia, Athens GA 30602,Department of Microbiology, University of Georgia, Athens GA 30602,To whom correspondence should be addressed:
| |
Collapse
|
56
|
Ingle S, Chhabra S, Chen J, Lazarus MB, Luo X, Bechhofer DH. Discovery and initial characterization of YloC, a novel endoribonuclease in Bacillus subtilis. RNA (NEW YORK, N.Y.) 2022; 28:227-238. [PMID: 34815358 PMCID: PMC8906540 DOI: 10.1261/rna.078962.121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 11/02/2021] [Indexed: 06/13/2023]
Abstract
The Bacillus subtilis genome is predicted to encode numerous ribonucleases, including four 3' exoribonucleases that have been characterized to some extent. A strain containing gene knockouts of all four known 3' exoribonucleases is viable, suggesting that one or more additional RNases remain to be discovered. A protein extract from the quadruple RNase mutant strain was fractionated and RNase activity was followed, resulting in the identification of an enzyme activity catalyzed by the YloC protein. YloC is an endoribonuclease and is a member of the highly conserved "YicC family" of proteins that is widespread in bacteria. YloC is a metal-dependent enzyme that catalyzes the cleavage of single-stranded RNA, preferentially at U residues, and exists in an oligomeric form, most likely a hexamer. As such, YloC shares some characteristics with the SARS-CoV Nsp15 endoribonuclease. While the in vivo function of YloC in B. subtilis is yet to be determined, YloC was found to act similarly to YicC in an Escherichia coli in vivo assay that assesses decay of the small RNA, RyhB. Thus, YloC may play a role in small RNA regulation.
Collapse
Affiliation(s)
- Shakti Ingle
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Shivani Chhabra
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Jiandong Chen
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Michael B Lazarus
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Xing Luo
- Laboratory of Molecular Biology, National Cancer Institute, Bethesda, Maryland 20892, USA
| | - David H Bechhofer
- Department of Pharmacology and Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| |
Collapse
|
57
|
Ogura M. Identification of transposon-inserted mutations including rnpB::Tn that abolished glucose induction of sigX encoding extracytoplasmic function-sigma factor in Bacillus subtilis. Biosci Biotechnol Biochem 2022; 86:282-285. [PMID: 34864869 DOI: 10.1093/bbb/zbab211] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 11/27/2021] [Indexed: 11/13/2022]
Abstract
We investigated the regulators of the glucose induction (GI) of the ECF-sigma genes sigX/M. During further screening of transposon-inserted mutants, we identified several regulators including an RNA component of RNase P (rnpB), which is required for tRNA maturation. A depletion of rnpB is known to trigger the stringent response. We showed evidence that the stringent response inhibited GI of sigX/M.
Collapse
Affiliation(s)
- Mitsuo Ogura
- Institute of Oceanic Research and Development, Tokai University, Orido, Shizuoka, Japan
| |
Collapse
|
58
|
Jüttner M, Ferreira-Cerca S. A Comparative Perspective on Ribosome Biogenesis: Unity and Diversity Across the Tree of Life. Methods Mol Biol 2022; 2533:3-22. [PMID: 35796979 PMCID: PMC9761495 DOI: 10.1007/978-1-0716-2501-9_1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Ribosomes are universally conserved ribonucleoprotein complexes involved in the decoding of the genetic information contained in messenger RNAs into proteins. Accordingly, ribosome biogenesis is a fundamental cellular process required for functional ribosome homeostasis and to preserve satisfactory gene expression capability.Although the ribosome is universally conserved, its biogenesis shows an intriguing degree of variability across the tree of life . These differences also raise yet unresolved questions. Among them are (a) what are, if existing, the remaining ancestral common principles of ribosome biogenesis ; (b) what are the molecular impacts of the evolution history and how did they contribute to (re)shape the ribosome biogenesis pathway across the tree of life ; (c) what is the extent of functional divergence and/or convergence (functional mimicry), and in the latter case (if existing) what is the molecular basis; (d) considering the universal ribosome conservation, what is the capability of functional plasticity and cellular adaptation of the ribosome biogenesis pathway?In this review, we provide a brief overview of ribosome biogenesis across the tree of life and try to illustrate some potential and/or emerging answers to these unresolved questions.
Collapse
Affiliation(s)
- Michael Jüttner
- Biochemistry III-Regensburg Center for Biochemistry-Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Regensburg, Germany
| | - Sébastien Ferreira-Cerca
- Biochemistry III-Regensburg Center for Biochemistry-Institute for Biochemistry, Genetics and Microbiology, University of Regensburg, Regensburg, Germany.
| |
Collapse
|
59
|
Streamlining cell-free protein synthesis biosensors for use in human fluids: In situ RNase inhibitor production during extract preparation. Biochem Eng J 2022. [DOI: 10.1016/j.bej.2021.108158] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
60
|
Mohanty BK, Kushner SR. Inactivation of RNase P in Escherichia coli significantly changes post-transcriptional RNA metabolism. Mol Microbiol 2022; 117:121-142. [PMID: 34486768 PMCID: PMC8766891 DOI: 10.1111/mmi.14808] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 09/01/2021] [Accepted: 09/02/2021] [Indexed: 01/03/2023]
Abstract
Ribonuclease P (RNase P), which is required for the 5'-end maturation of tRNAs in every organism, has been shown to play a limited role in other aspects of RNA metabolism in Escherichia coli. Using RNA-sequencing (RNA-seq), we demonstrate that RNase P inactivation affects the abundances of ~46% of the expressed transcripts in E. coli and provide evidence that its essential function is its ability to generate pre-tRNAs from polycistronic tRNA transcripts. The RNA-seq results agreed with the published data and northern blot analyses of 75/83 transcripts (mRNAs, sRNAs, and tRNAs). Changes in transcript abundances in the RNase P mutant also correlated with changes in their half-lives. Inactivating the stringent response did not alter the rnpA49 phenotype. Most notably, increases in the transcript abundances were observed for all genes in the cysteine regulons, multiple toxin-antitoxin modules, and sigma S-controlled genes. Surprisingly, poly(A) polymerase (PAP I) modulated the abundances of ~10% of the transcripts affected by RNase P. A comparison of the transcriptomes of RNase P, RNase E, and RNase III mutants suggests that they affect distinct substrates. Together, our work strongly indicates that RNase P is a major player in all aspects of post-transcriptional RNA metabolism in E. coli.
Collapse
Affiliation(s)
| | - Sidney R. Kushner
- Department of Genetics, University of Georgia, Athens, GA 30602,Department of Microbiology, University of Georgia, Athens, GA 30602,To whom correspondence should be addressed.
| |
Collapse
|
61
|
Chou-Zheng L, Hatoum-Aslan A. Critical roles for 'housekeeping' nucleases in type III CRISPR-Cas immunity. eLife 2022; 11:81897. [PMID: 36479971 PMCID: PMC9762709 DOI: 10.7554/elife.81897] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
CRISPR-Cas systems are a family of adaptive immune systems that use small CRISPR RNAs (crRNAs) and CRISPR-associated (Cas) nucleases to protect prokaryotes from invading plasmids and viruses (i.e., phages). Type III systems launch a multilayered immune response that relies upon both Cas and non-Cas cellular nucleases, and although the functions of Cas components have been well described, the identities and roles of non-Cas participants remain poorly understood. Previously, we showed that the type III-A CRISPR-Cas system in Staphylococcus epidermidis employs two degradosome-associated nucleases, PNPase and RNase J2, to promote crRNA maturation and eliminate invading nucleic acids (Chou-Zheng and Hatoum-Aslan, 2019). Here, we identify RNase R as a third 'housekeeping' nuclease critical for immunity. We show that RNase R works in concert with PNPase to complete crRNA maturation and identify specific interactions with Csm5, a member of the type III effector complex, which facilitate nuclease recruitment/stimulation. Furthermore, we demonstrate that RNase R and PNPase are required to maintain robust anti-plasmid immunity, particularly when targeted transcripts are sparse. Altogether, our findings expand the known repertoire of accessory nucleases required for type III immunity and highlight the remarkable capacity of these systems to interface with diverse cellular pathways to ensure successful defense.
Collapse
Affiliation(s)
- Lucy Chou-Zheng
- Microbiology Department, University of Illinois Urbana-ChampaignUrbanaUnited States
| | - Asma Hatoum-Aslan
- Microbiology Department, University of Illinois Urbana-ChampaignUrbanaUnited States
| |
Collapse
|
62
|
Yi B, Dalpke AH. Revisiting the intrageneric structure of the genus Pseudomonas with complete whole genome sequence information: Insights into diversity and pathogen-related genetic determinants. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2022; 97:105183. [PMID: 34920102 DOI: 10.1016/j.meegid.2021.105183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 08/09/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Pseudomonas spp. exhibit considerable differences in host specificity and virulence. Most Pseudomonas species were isolated exclusively from environmental sources, ranging from soil to plants, but some Pseudomonas species have been detected from versatile sources, including both human host and environmental sources. Understanding genome variations that generate the tremendous diversity in Pseudomonas biology is important in controlling the incidence of infections. With a data set of 704 Pseudomonas complete whole genome sequences representing 186 species, Pseudomonas intrageneric structure was investigated by hierarchical clustering based on average nucleotide identity, and by phylogeny analysis based on concatenated core-gene alignment. Further comparative functional analyses indicated that Pseudomonas species only living in natural habitats lack multiple functions that are important in the regulation of bacterial pathogenesis, indicating the possession of these functions might be characteristic of Pseudomonas human pathogens. Moreover, we have performed pan-genome based homogeneity analyses, and detected genes with conserved structures but diversified functions across the Pseudomonas genomes, suggesting these genes play a role in driving diversity. In summary, this study provided insights into the dynamics of genome diversity and pathogen-related genetic determinants in Pseudomonas, which might help the development of more targeted antibiotics for the treatment of Pseudomonas infections.
Collapse
Affiliation(s)
- Buqing Yi
- Institute of Medical Microbiology and Virology, Medical Faculty, Technische Universität Dresden, Dresden, Germany.
| | - Alexander H Dalpke
- Institute of Medical Microbiology and Virology, Medical Faculty, Technische Universität Dresden, Dresden, Germany.
| |
Collapse
|
63
|
Nagy I, Szabó M, Hegyi A, Kiss J. Salmonella Genomic Island 1 requires a self-encoded small RNA for mobilization. Mol Microbiol 2021; 116:1533-1551. [PMID: 34784078 PMCID: PMC9299015 DOI: 10.1111/mmi.14846] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/08/2021] [Accepted: 11/13/2021] [Indexed: 11/29/2022]
Abstract
The SGI1-family elements that are specifically mobilized by the IncA- and IncC-family plasmids are important vehicles of antibiotic resistance among enteric bacteria. Although SGI1 exploits many plasmid-derived conjugation and regulatory functions, the basic mobilization module of the island is unrelated to that of IncC plasmids. This module contains the oriT and encodes the mobilization proteins MpsA and MpsB, which belong to the tyrosine recombinases and not to relaxases. Here we report an additional, essential transfer factor of SGI1. This is a small RNA deriving from the 3'-end of a primary RNA that can also serve as mRNA of ORF S022. The functional domain of this sRNA named sgm-sRNA is encoded between the mpsA gene and the oriT of SGI1. Terminator-like sequence near the promoter of the primary transcript possibly has a regulatory function in controlling the amount of full-length primary RNA, which is converted to the active sgm-sRNA through consecutive maturation steps influenced by the 5'-end of the primary RNA. The mobilization module of SGI1 seems unique due to its atypical relaxase and the newly identified sgm-sRNA, which is required for the horizontal transfer of the island but appears to act differently from classical regulatory sRNAs.
Collapse
Affiliation(s)
- István Nagy
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Mónika Szabó
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - Anna Hegyi
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| | - János Kiss
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Gödöllő, Hungary
| |
Collapse
|
64
|
Shatoff EA, Gemler BT, Bundschuh R, Fredrick K. Maturation of 23S rRNA includes removal of helix H1 in many bacteria. RNA Biol 2021; 18:856-865. [PMID: 34812116 PMCID: PMC8782170 DOI: 10.1080/15476286.2021.2000793] [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] [Indexed: 11/17/2022] Open
Abstract
In most bacteria, the three ribosomal RNAs (rRNAs) are encoded together in each of several near-identical operons. As soon as the nascent precursor rRNA emerges from RNA polymerase, ribosome assembly begins. This process entails ribosomal protein binding, rRNA folding, rRNA modification, and rRNA processing. In the model organisms Escherichia coli and Bacillus subtilis, rRNA processing results in similar mature rRNAs, despite substantial differences in the cohort of RNAses involved. A recent study of Flavobacterium johnsoniae, a member of the phylum Bacteroidota (formerly Bacteroidetes), revealed that helix H1 of 23S rRNA is absent from ribosomes, apparently a consequence of rRNA maturation. In this work, we mined RNA-seq data from 19 individual organisms and ocean metatranscriptomic samples to compare rRNA processing across diverse bacterial lineages. We found that mature ribosomes from multiple clades lack H1, and typically these ribosomes also lack an encoded H98. For all groups analysed, H1 is predicted to form in precursor rRNA as part of a longer leader-trailer helix. Hence, we infer that evolutionary loss of H98 sets the stage for H1 removal during 50S subunit maturation.
Collapse
Affiliation(s)
- Elan A Shatoff
- Department of Physics, The Ohio State University, Columbus, OH, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH, USA
| | - Bryan T Gemler
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA.,Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Ralf Bundschuh
- Department of Physics, The Ohio State University, Columbus, OH, USA.,Center for RNA Biology, The Ohio State University, Columbus, OH, USA.,Interdisciplinary Biophysics Graduate Program, The Ohio State University, Columbus, OH, USA.,Department of Chemistry & Biochemistry, The Ohio State University, Columbus, OH, USA.,Division of Hematology, Department of Internal Medicine, The Ohio State University, Columbus, OH, USA
| | - Kurt Fredrick
- Center for RNA Biology, The Ohio State University, Columbus, OH, USA.,Department of Microbiology, The Ohio State University, Columbus, OH, USA
| |
Collapse
|
65
|
Apura P, Gonçalves LG, Viegas SC, Arraiano CM. The world of ribonucleases from pseudomonads: a short trip through the main features and singularities. Microb Biotechnol 2021; 14:2316-2333. [PMID: 34427985 PMCID: PMC8601179 DOI: 10.1111/1751-7915.13890] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 06/30/2021] [Indexed: 11/27/2022] Open
Abstract
The development of synthetic biology has brought an unprecedented increase in the number molecular tools applicable into a microbial chassis. The exploration of such tools into different bacteria revealed not only the challenges of context dependency of biological functions but also the complexity and diversity of regulatory layers in bacterial cells. Most of the standardized genetic tools and principles/functions have been mostly based on model microorganisms, namely Escherichia coli. In contrast, the non-model pseudomonads lack a deeper understanding of their regulatory layers and have limited molecular tools. They are resistant pathogens and promising alternative bacterial chassis, making them attractive targets for further studies. Ribonucleases (RNases) are key players in the post-transcriptional control of gene expression by degrading or processing the RNA molecules in the cell. These enzymes act according to the cellular requirements and can also be seen as the recyclers of ribonucleotides, allowing a continuous input of these cellular resources. This makes these post-transcriptional regulators perfect candidates to regulate microbial physiology. This review summarizes the current knowledge and unique properties of ribonucleases in the world of pseudomonads, taking into account genomic context analysis, biological function and strategies to use ribonucleases to improve biotechnological processes.
Collapse
Affiliation(s)
- Patrícia Apura
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Luis G. Gonçalves
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Sandra C. Viegas
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| | - Cecília M. Arraiano
- Instituto de Tecnologia Química e Biológica António XavierUniversidade Nova de LisboaAv. da República, EANOeiras2780‐157Portugal
| |
Collapse
|
66
|
Mohiuddin SG, Ghosh S, Ngo HG, Sensenbach S, Karki P, Dewangan NK, Angardi V, Orman MA. Cellular Self-Digestion and Persistence in Bacteria. Microorganisms 2021; 9:2269. [PMID: 34835393 PMCID: PMC8626048 DOI: 10.3390/microorganisms9112269] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/30/2022] Open
Abstract
Cellular self-digestion is an evolutionarily conserved process occurring in prokaryotic cells that enables survival under stressful conditions by recycling essential energy molecules. Self-digestion, which is triggered by extracellular stress conditions, such as nutrient depletion and overpopulation, induces degradation of intracellular components. This self-inflicted damage renders the bacterium less fit to produce building blocks and resume growth upon exposure to fresh nutrients. However, self-digestion may also provide temporary protection from antibiotics until the self-digestion-mediated damage is repaired. In fact, many persistence mechanisms identified to date may be directly or indirectly related to self-digestion, as these processes are also mediated by many degradative enzymes, including proteases and ribonucleases (RNases). In this review article, we will discuss the potential roles of self-digestion in bacterial persistence.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Mehmet A. Orman
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77004, USA; (S.G.M.); (S.G.); (H.G.N.); (S.S.); (P.K.); (N.K.D.); (V.A.)
| |
Collapse
|
67
|
RNase Z Oxidative Degradation Impedes tRNA Maturation and is Involved in Streptococcal Translation Regulation in Response to Oxidative Stress. Microbiol Spectr 2021; 9:e0116721. [PMID: 34704809 PMCID: PMC8549757 DOI: 10.1128/spectrum.01167-21] [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] [Indexed: 11/24/2022] Open
Abstract
When encountering oxidative stress, organisms selectively upregulate antioxidant genes and simultaneously suppress the translation of most other proteins. Eukaryotes employ multiple strategies to adjust translation at both the initiation and elongation stages; however, how prokaryotes modulate translation under oxidative stress remains unclear. Here, we report that upon hydrogen peroxide (H2O2) challenge, Streptococcus oligofermentans reduced translation via RNase Z (So-RNaseZ) oxidative degradation, thus hindering tRNA maturation. S. oligofermentans encodes all CCA-less tRNAs that require So-RNaseZ for 3′ end maturation. A combination of nonreducing SDS-PAGE and liquid chromatography/tandem mass spectrometry (LC/MS-MS) assays demonstrated that H2O2 oxidation induced Cys38-Cys149 disulfide linkages in recombinant So-RNaseZ protein, and serine substitution of Cys38 or Cys149 abolished these disulfide linkages. Consistently, redox Western blotting also determined intramolecular disulfide-linked So-RNaseZ in H2O2-treated S. oligofermentans cells. The disulfide-linked So-RNaseZ and monomer were both subject to proteolysis, whereas C149S mutation alleviated oxidative degradation of So-RNaseZ, suggesting that H2O2-mediated disulfide linkages substantially contributed to So-RNaseZ degradation. Accordingly, Northern blotting determined that tRNA precursor accumulation and mature tRNA species decrease in H2O2-treated S. oligofermentans. Moreover, reduced overall protein synthesis, as indicated by puromycin incorporation, and retarded growth of S. oligofermentans occurred in an H2O2 concentration-dependent manner. Overexpression of So-RNaseZ not only elevated tRNA precursor processing and protein synthesis but also partly rescued H2O2-suppressed S. oligofermentans growth. Moreover, So-RNaseZ oxidative degradation-mediated translation repression elevated S. oligofermentans survival under high H2O2 stress. Therefore, this work found that So-RNaseZ oxidative degradation-impeded tRNA maturation contributes to streptococcal translation repression and provides the oxidative stress adaptability for S. oligofermentans. IMPORTANCE Translation regulation is a common strategy used by organisms to reduce oxidative damage. Catalase-negative streptococci produce as well as tolerate high levels of H2O2. This work reports a novel translation regulation mechanism employed by Streptococcus oligofermentans in response to H2O2 challenge, in which the key tRNA endonuclease So-RNaseZ is oxidized to form Cys38-Cys149 disulfide linkages and both the disulfide-linked So-RNaseZ and monomers are subject to proteolysis; thus, tRNA maturation, protein translation, and growth are all suppressed. Notably, So-RNaseZ oxidative degradation-mediated translation repression offers oxidative adaptability to S. oligofermentans and enhances its survival against high H2O2 challenge. So-RNaseZ orthologs and H2O2-sensitive cysteines (Cys38 and Cys149) are widely distributed in Streptococcus and Lactococcus species genomes, which also encode all CCA-less tRNAs and lack catalase. Therefore, RNase Z oxidative degradation-based translation regulation could be widely employed by these lactic acid bacteria, including pathogenic streptococci, to cope with H2O2.
Collapse
|
68
|
Polyribosome-Dependent Clustering of Membrane-Anchored RNA Degradosomes To Form Sites of mRNA Degradation in Escherichia coli. mBio 2021; 12:e0193221. [PMID: 34488454 PMCID: PMC8546579 DOI: 10.1128/mbio.01932-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
The essential endoribonuclease RNase E, which is a component of the Escherichia coli multienzyme RNA degradosome, has a global role in RNA processing and degradation. RNase E localizes to the inner cytoplasmic membrane in small, short-lived clusters (puncta). Rifampin, which arrests transcription, inhibits RNase E clustering and increases its rate of diffusion. Here, we show that inhibition of clustering is due to the arrest of transcription using a rifampin-resistant control strain. Two components of the RNA degradosome, the 3′ exoribonuclease polynucleotide phosphorylase (PNPase) and the DEAD box RNA helicase RhlB, colocalize with RNase E in puncta. Clustering of PNPase and RhlB is inhibited by rifampin, and their diffusion rates increase, as evidenced by in vivo photobleaching measurements. Results with rifampin treatment reported here show that RNA degradosome diffusion is constrained by interaction with RNA substrate. Kasugamycin, which arrests translation initiation, inhibits formation of puncta and increases RNA degradosome diffusion rates. Since kasugamycin treatment results in continued synthesis and turnover of ribosome-free mRNA but inhibits polyribosome formation, RNA degradosome clustering is therefore polyribosome dependent. Chloramphenicol, which arrests translation elongation, results in formation of large clusters (foci) of RNA degradosomes that are distinct from puncta. Since chloramphenicol-treated ribosomes are stable, the formation of RNA degradosome foci could be part of a stress response that protects inactive polyribosomes from degradation. Our results strongly suggest that puncta are sites where translationally active polyribosomes are captured by membrane-associated RNA degradosomes. These sites could be part of a scanning process that is an initial step in mRNA degradation.
Collapse
|
69
|
Cell-Free Protein Synthesis by Diversifying Bacterial Transcription Machinery. BIOTECH 2021; 10:biotech10040024. [PMID: 35822798 PMCID: PMC9245472 DOI: 10.3390/biotech10040024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 10/06/2021] [Accepted: 10/08/2021] [Indexed: 11/17/2022] Open
Abstract
We have evaluated several approaches to increase protein synthesis in a cell-free coupled bacterial transcription and translation system. A strong pargC promoter, originally isolated from a moderate thermophilic bacterium Geobacillus stearothermophilus, was used to improve the performance of a cell-free system in extracts of Escherichia coli BL21 (DE3). A stimulating effect on protein synthesis was detected with extracts prepared from recombinant cells, in which the E. coli RNA polymerase subunits α, β, β’ and ω are simultaneously coexpressed. Appending a 3′ UTR genomic sequence and a T7 transcription terminator to the protein-coding region also improves the synthetic activity of some genes from linear DNA. The E. coli BL21 (DE3) rna::Tn10 mutant deficient in a periplasmic RNase I was constructed. The mutant cell-free extract increases by up to four-fold the expression of bacterial and human genes mediated from both bacterial pargC and phage pT7 promoters. By contrast, the RNase E deficiency does not affect the cell-free expression of the same genes. The regulatory proteins of the extremophilic bacterium Thermotoga, synthesized in a cell-free system, can provide the binding capacity to target DNA regions. The advantageous characteristics of cell-free systems described open attractive opportunities for high-throughput screening assays.
Collapse
|
70
|
Abstract
Ribonucleases are useful as biomarkers and can be the source of contamination in laboratory samples, making ribonuclease detection assays important in life sciences research. With recent developments in DNA-based biosensing, several new techniques are being developed to detect ribonucleases. This review discusses some of these methods, specifically those that utilize G-quadruplex DNA structures, DNA-nanoparticle conjugates and DNA nanostructures, and the advantages and challenges associated with them.
Collapse
|
71
|
Machado de Amorim A, Chakrabarti S. Assembly of multicomponent machines in RNA metabolism: A common theme in mRNA decay pathways. WILEY INTERDISCIPLINARY REVIEWS-RNA 2021; 13:e1684. [PMID: 34351053 DOI: 10.1002/wrna.1684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/05/2022]
Abstract
Multicomponent protein-RNA complexes comprising a ribonuclease and partner RNA helicase facilitate the turnover of mRNA in all domains of life. While these higher-order complexes provide an effective means of physically and functionally coupling the processes of RNA remodeling and decay, most ribonucleases and RNA helicases do not exhibit sequence specificity in RNA binding. This raises the question as to how these assemblies select substrates for processing and how the activities are orchestrated at the precise moment to ensure efficient decay. The answers to these apparent puzzles lie in the auxiliary components of the assemblies that might relay decay-triggering signals. Given their function within the assemblies, these components may be viewed as "sensors." The functions and mechanisms of action of the sensor components in various degradation complexes in bacteria and eukaryotes are highlighted here to discuss their roles in RNA decay processes. This article is categorized under: RNA Turnover and Surveillance > Regulation of RNA Stability RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms RNA Interactions with Proteins and Other Molecules > Protein-RNA Recognition.
Collapse
Affiliation(s)
| | - Sutapa Chakrabarti
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| |
Collapse
|
72
|
Abstract
Bacterial protein synthesis rates have evolved to maintain preferred stoichiometries at striking precision, from the components of protein complexes to constituents of entire pathways. Setting relative protein production rates to be well within a factor of two requires concerted tuning of transcription, RNA turnover, and translation, allowing many potential regulatory strategies to achieve the preferred output. The last decade has seen a greatly expanded capacity for precise interrogation of each step of the central dogma genome-wide. Here, we summarize how these technologies have shaped the current understanding of diverse bacterial regulatory architectures underpinning stoichiometric protein synthesis. We focus on the emerging expanded view of bacterial operons, which encode diverse primary and secondary mRNA structures for tuning protein stoichiometry. Emphasis is placed on how quantitative tuning is achieved. We discuss the challenges and open questions in the application of quantitative, genome-wide methodologies to the problem of precise protein production. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- James C Taggart
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; ,
| | - Jean-Benoît Lalanne
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; , .,Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.,Current affiliation: Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA;
| | - Gene-Wei Li
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA; ,
| |
Collapse
|
73
|
Roux C, Etienne TA, Hajnsdorf E, Ropers D, Carpousis AJ, Cocaign-Bousquet M, Girbal L. The essential role of mRNA degradation in understanding and engineering E. coli metabolism. Biotechnol Adv 2021; 54:107805. [PMID: 34302931 DOI: 10.1016/j.biotechadv.2021.107805] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 06/28/2021] [Accepted: 07/14/2021] [Indexed: 11/17/2022]
Abstract
Metabolic engineering strategies are crucial for the development of bacterial cell factories with improved performance. Until now, optimal metabolic networks have been designed based on systems biology approaches integrating large-scale data on the steady-state concentrations of mRNA, protein and metabolites, sometimes with dynamic data on fluxes, but rarely with any information on mRNA degradation. In this review, we compile growing evidence that mRNA degradation is a key regulatory level in E. coli that metabolic engineering strategies should take into account. We first discuss how mRNA degradation interacts with transcription and translation, two other gene expression processes, to balance transcription regulation and remove poorly translated mRNAs. The many reciprocal interactions between mRNA degradation and metabolism are also highlighted: metabolic activity can be controlled by changes in mRNA degradation and in return, the activity of the mRNA degradation machinery is controlled by metabolic factors. The mathematical models of the crosstalk between mRNA degradation dynamics and other cellular processes are presented and discussed with a view towards novel mRNA degradation-based metabolic engineering strategies. We show finally that mRNA degradation-based strategies have already successfully been applied to improve heterologous protein synthesis. Overall, this review underlines how important mRNA degradation is in regulating E. coli metabolism and identifies mRNA degradation as a key target for innovative metabolic engineering strategies in biotechnology.
Collapse
Affiliation(s)
- Charlotte Roux
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France; UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Thibault A Etienne
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France; Univ. Grenoble Alpes, Inria, 38000 Grenoble, France.
| | - Eliane Hajnsdorf
- UMR8261, CNRS, Université de Paris, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | | | - A J Carpousis
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France; LMGM, Université de Toulouse, CNRS, UPS, CBI, 31062 Toulouse, France.
| | | | - Laurence Girbal
- TBI, Université de Toulouse, CNRS, INRAE, INSA, 31077 Toulouse, France.
| |
Collapse
|
74
|
Hibernation-Promoting Factor Sequesters Staphylococcus aureus Ribosomes to Antagonize RNase R-Mediated Nucleolytic Degradation. mBio 2021; 12:e0033421. [PMID: 34253058 PMCID: PMC8406268 DOI: 10.1128/mbio.00334-21] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Bacterial and eukaryotic hibernation factors prevent translation by physically blocking the decoding center of ribosomes, a phenomenon called ribosome hibernation that often occurs in response to nutrient deprivation. The human pathogen Staphylococcus aureus lacking the sole hibernation factor HPF undergoes massive ribosome degradation via an unknown pathway. Using genetic and biochemical approaches, we find that inactivating the 3′-to-5′ exonuclease RNase R suppresses ribosome degradation in the Δhpf mutant. In vitro cell-free degradation assays confirm that 30S and 70S ribosomes isolated from the Δhpf mutant are extremely susceptible to RNase R, in stark contrast to nucleolytic resistance of the HPF-bound 70S and 100S complexes isolated from the wild type. In the absence of HPF, specific S. aureus 16S rRNA helices are sensitive to nucleolytic cleavage. These RNase hot spots are distinct from that found in the Escherichia coli ribosomes. S. aureus RNase R is associated with ribosomes, but unlike the E. coli counterpart, it is not regulated by general stressors and acetylation. The results not only highlight key differences between the evolutionarily conserved RNase R homologs but also provide direct evidence that HPF preserves ribosome integrity beyond its role in translational avoidance, thereby poising the hibernating ribosomes for rapid resumption of translation.
Collapse
|
75
|
A fluorescence-based genetic screen reveals diverse mechanisms silencing small RNA signaling in E. coli. Proc Natl Acad Sci U S A 2021; 118:2106964118. [PMID: 34210798 DOI: 10.1073/pnas.2106964118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
As key players of gene regulation in many bacteria, small regulatory RNAs (sRNAs) associated with the RNA chaperone Hfq shape numerous phenotypic traits, including metabolism, stress response and adaptation, as well as virulence. sRNAs can alter target messenger RNA (mRNA) translation and stability via base pairing. sRNA synthesis is generally under tight transcriptional regulation, but other levels of regulation of sRNA signaling are less well understood. Here we used a fluorescence-based functional screen to identify regulators that can quench sRNA signaling of the iron-responsive sRNA RyhB in Escherichia coli The identified regulators fell into two classes, general regulators (affecting signaling by many sRNAs) and RyhB-specific regulators; we focused on the specific ones here. General regulators include three Hfq-interacting sRNAs, CyaR, ChiX, and McaS, previously found to act through Hfq competition, RNase T, a 3' to 5' exonuclease not previously implicated in sRNA degradation, and YhbS, a putative GCN5-related N-acetyltransferase (GNAT). Two specific regulators were identified. AspX, a 3'end-derived small RNA, specifically represses RyhB signaling via an RNA sponging mechanism. YicC, a previously uncharacterized but widely conserved protein, triggers rapid RyhB degradation via collaboration with the exoribonuclease PNPase. These findings greatly expand our knowledge of regulation of bacterial sRNA signaling and suggest complex regulatory networks for controlling iron homeostasis in bacteria. The fluorescence-based genetic screen system described here is a powerful tool expected to accelerate the discovery of novel regulators of sRNA signaling in many bacteria.
Collapse
|
76
|
Levels and Characteristics of mRNAs in Spores of Firmicute Species. J Bacteriol 2021; 203:e0001721. [PMID: 33972352 DOI: 10.1128/jb.00017-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spores of firmicute species contain 100s of mRNAs, whose major function in Bacillus subtilis is to provide ribonucleotides for new RNA synthesis when spores germinate. To determine if this is a general phenomenon, RNA was isolated from spores of multiple firmicute species and relative mRNA levels determined by transcriptome sequencing (RNA-seq). Determination of RNA levels in single spores allowed calculation of RNA nucleotides/spore, and assuming mRNA is 3% of spore RNA indicated that only ∼6% of spore mRNAs were present at >1/spore. Bacillus subtilis, Bacillus atrophaeus, and Clostridioides difficile spores had 49, 42, and 51 mRNAs at >1/spore, and numbers of mRNAs at ≥1/spore were ∼10 to 50% higher in Geobacillus stearothermophilus and Bacillus thuringiensis Al Hakam spores and ∼4-fold higher in Bacillus megaterium spores. In all species, some to many abundant spore mRNAs (i) were transcribed by RNA polymerase with forespore-specific σ factors, (ii) encoded proteins that were homologs of those encoded by abundant B. subtilis spore mRNAs and are proteins in dormant spores, and (iii) were likely transcribed in the mother cell compartment of the sporulating cell. Analysis of the coverage of RNA-seq reads on mRNAs from all species suggested that abundant spore mRNAs were fragmented, as was confirmed by reverse transcriptase quantitative PCR (RT-qPCR) analysis of abundant B. subtilis and C. difficile spore mRNAs. These data add to evidence indicating that the function of at least the great majority of mRNAs in all firmicute spores is to be degraded to generate ribonucleotides for new RNA synthesis when spores germinate. IMPORTANCE Only ∼6% of mRNAs in spores of six firmicute species are at ≥1 molecule/spore, many abundant spore mRNAs encode proteins similar to B. subtilis spore proteins, and some abundant B. subtilis and C. difficile spore mRNAs were fragmented. Most of the abundant B. subtilis and other Bacillales spore mRNAs are transcribed under the control of the forespore-specific RNA polymerase σ factors, F or G, and these results may stimulate transcription analyses in developing spores of species other than B. subtilis. These findings, plus the absence of key nucleotide biosynthetic enzymes in spores, suggest that firmicute spores' abundant mRNAs are not translated when spores germinate but instead are degraded to generate ribonucleotides for new RNA synthesis by the germinated spore.
Collapse
|
77
|
Xu SY, Fomenkov A, Chen TH, Yigit E. Expression of Human ACE2 N-terminal Domain, Part of the Receptor for SARS-CoV-2, in Fusion With Maltose-Binding Protein, E. coli Ribonuclease I and Human RNase A. Front Microbiol 2021; 12:660149. [PMID: 34177838 PMCID: PMC8226257 DOI: 10.3389/fmicb.2021.660149] [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: 01/29/2021] [Accepted: 04/16/2021] [Indexed: 12/28/2022] Open
Abstract
The SARS-CoV-2 viral genome contains a positive-strand single-stranded RNA of ∼30 kb. Human ACE2 protein is the receptor for SARS-CoV-2 virus attachment and infection. We propose to use ribonucleases (RNases) as antiviral agents to destroy the viral genome in vitro. In the virions, the RNA is protected by viral capsid proteins, membrane proteins, and nucleocapsid proteins. To utilize RNases as antiviral strategy, we set out to construct RNase fusion with human ACE2 receptor N-terminal domain (ACE2NTD). We expressed six proteins in E. coli cells: (1) MBP-ACE2NTD, (2) ACE2NTD-GFP, (3) RNase I (6×His), (4) RNase III (6×His), (5) RNase I-ACE2NTD (6×His), and (6) human RNase A-ACE2NTD (6×His). We evaluated fusion expression in different E. coli strains, partially purified MBP-ACE2NTD protein from the soluble fraction of bacterial cell lysate, and refolded MBP-ACE2NTD protein from inclusion body. The engineered RNase I-ACE2NTD (6×His) and hRNase A-ACE2NTD (6×His) fusions are active in cleaving SARS-CoV-2 RNA fragment in vitro. The recombinant RNase I (6×His) and RNase III (6×His) are active in cleaving RNA and dsRNA in test tube. This study provides a proof-of-concept for construction of fusion protein between human receptor and nuclease that may be used to degrade viral nucleic acids.
Collapse
|
78
|
Abstract
Ribonucleases (RNases) are essential for almost every aspect of RNA metabolism. However, despite their important metabolic roles, RNases can also be destructive enzymes. As a consequence, cells must carefully regulate the amount, the activity, and the localization of RNases to avoid the inappropriate degradation of essential RNA molecules. In addition, bacterial cells often must adjust RNase levels as environmental situations demand, also requiring careful regulation of these critical enzymes. As the need for strict control of RNases has become more evident, multiple mechanisms for this regulation have been identified and studied, and these are described in this review. The major conclusion that emerges is that no common regulatory mechanism applies to all RNases, or even to a family of RNases; rather, a wide variety of processes have evolved that act on these enzymes, and in some cases, multiple regulatory mechanisms can even act on a single RNase. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Murray P Deutscher
- Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami, Miami, Florida 33101, USA;
| |
Collapse
|
79
|
Tandem Repeats in Bacillus: Unique Features and Taxonomic Distribution. Int J Mol Sci 2021; 22:ijms22105373. [PMID: 34065296 PMCID: PMC8161180 DOI: 10.3390/ijms22105373] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 05/14/2021] [Accepted: 05/18/2021] [Indexed: 11/16/2022] Open
Abstract
Little is known about DNA tandem repeats across prokaryotes. We have recently described an enigmatic group of tandem repeats in bacterial genomes with a constant repeat size but variable sequence. These findings strongly suggest that tandem repeat size in some bacteria is under strong selective constraints. Here, we extend these studies and describe tandem repeats in a large set of Bacillus. Some species have very few repeats, while other species have a large number. Most tandem repeats have repeats with a constant size (either 52 or 20-21 nt), but a variable sequence. We characterize in detail these intriguing tandem repeats. Individual species have several families of tandem repeats with the same repeat length and different sequence. This result is in strong contrast with eukaryotes, where tandem repeats of many sizes are found in any species. We discuss the possibility that they are transcribed as small RNA molecules. They may also be involved in the stabilization of the nucleoid through interaction with proteins. We also show that the distribution of tandem repeats in different species has a taxonomic significance. The data we present for all tandem repeats and their families in these bacterial species will be useful for further genomic studies.
Collapse
|
80
|
Markelova N, Glazunova O, Alikina O, Panyukov V, Shavkunov K, Ozoline O. Suppression of Escherichia coli Growth Dynamics via RNAs Secreted by Competing Bacteria. Front Mol Biosci 2021; 8:609979. [PMID: 33937321 PMCID: PMC8082180 DOI: 10.3389/fmolb.2021.609979] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 03/11/2021] [Indexed: 11/13/2022] Open
Abstract
With the discovery of secreted RNAs, it has become apparent that the biological role of regulatory oligonucleotides likely goes beyond the borders of individual cells. However, the mechanisms of their action are still comprehended only in general terms and mainly for eukaryotic microRNAs, which can interfere with mRNAs even in distant recipient cells. It has recently become clear that bacterial cells lacking interference systems can also respond to eukaryotic microRNAs that have targets in their genomes. However, the question of whether bacteria can perceive information transmitted by oligonucleotides secreted by other prokaryotes remained open. Here we evaluated the fraction of short RNAs secreted by Escherichia coli during individual and mixed growth with Rhodospirillum rubrum or Prevotella copri, and found that in the presence of other bacteria E. coli tends to excrete oligonucleotides homologous to alien genomes. Based on this observation, we selected four RNAs secreted by either R. rubrum or P. copri, together with one E. coli-specific oligonucleotide. Both fragments of R. rubrum 23S-RNA suppressed the growth of E. coli. Of the two fragments secreted by P. copri, one abolished the stimulatory effect of E. coli RNA derived from the 3'-UTR of ProA mRNA, while the other inhibited bacterial growth only in the double-stranded state with complementary RNA. The ability of two RNAs secreted by cohabiting bacteria to enter E. coli cells was demonstrated using confocal microscopy. Since selected E. coli-specific RNA also affected the growth of this bacterium, we conclude that bacterial RNAs can participate in inter- and intraspecies signaling.
Collapse
Affiliation(s)
- Natalia Markelova
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Olga Glazunova
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Olga Alikina
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Valeriy Panyukov
- Department of Structural and Functional Genomics, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia.,Laboratory of Bioinformatics, Institute of Mathematical Problems of Biology, Pushchino, Russia
| | - Konstantin Shavkunov
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia.,Department of Structural and Functional Genomics, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| | - Olga Ozoline
- Laboratory of Functional Genomics and Cellular Stress, Institute of Cell Biophysics of the Russian Academy of Sciences, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia.,Department of Structural and Functional Genomics, Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, Pushchino, Russia
| |
Collapse
|
81
|
Garcion C, Béven L, Foissac X. Comparison of Current Methods for Signal Peptide Prediction in Phytoplasmas. Front Microbiol 2021; 12:661524. [PMID: 33841387 PMCID: PMC8026896 DOI: 10.3389/fmicb.2021.661524] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 03/02/2021] [Indexed: 11/13/2022] Open
Abstract
Although phytoplasma studies are still hampered by the lack of axenic cultivation methods, the availability of genome sequences allowed dramatic advances in the characterization of the virulence mechanisms deployed by phytoplasmas, and highlighted the detection of signal peptides as a crucial step to identify effectors secreted by phytoplasmas. However, various signal peptide prediction methods have been used to mine phytoplasma genomes, and no general evaluation of these methods is available so far for phytoplasma sequences. In this work, we compared the prediction performance of SignalP versions 3.0, 4.0, 4.1, 5.0 and Phobius on several sequence datasets originating from all deposited phytoplasma sequences. SignalP 4.1 with specific parameters showed the most exhaustive and consistent prediction ability. However, the configuration of SignalP 4.1 for increased sensitivity induced a much higher rate of false positives on transmembrane domains located at N-terminus. Moreover, sensitive signal peptide predictions could similarly be achieved by the transmembrane domain prediction ability of TMHMM and Phobius, due to the relatedness between signal peptides and transmembrane regions. Beyond the results presented herein, the datasets assembled in this study form a valuable benchmark to compare and evaluate signal peptide predictors in a field where experimental evidence of secretion is scarce. Additionally, this study illustrates the utility of comparative genomics to strengthen confidence in bioinformatic predictions.
Collapse
Affiliation(s)
- Christophe Garcion
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Villenave d'Ornon, France
| | - Laure Béven
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Villenave d'Ornon, France
| | - Xavier Foissac
- INRAE, Univ. Bordeaux, Biologie du Fruit et Pathologie, UMR 1332, Villenave d'Ornon, France
| |
Collapse
|
82
|
Mandell ZF, Oshiro RT, Yakhnin AV, Vishwakarma R, Kashlev M, Kearns DB, Babitzke P. NusG is an intrinsic transcription termination factor that stimulates motility and coordinates gene expression with NusA. eLife 2021; 10:e61880. [PMID: 33835023 PMCID: PMC8060035 DOI: 10.7554/elife.61880] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 04/08/2021] [Indexed: 12/21/2022] Open
Abstract
NusA and NusG are transcription factors that stimulate RNA polymerase pausing in Bacillus subtilis. While NusA was known to function as an intrinsic termination factor in B. subtilis, the role of NusG in this process was unknown. To examine the individual and combinatorial roles that NusA and NusG play in intrinsic termination, Term-seq was conducted in wild type, NusA depletion, ΔnusG, and NusA depletion ΔnusG strains. We determined that NusG functions as an intrinsic termination factor that works alone and cooperatively with NusA to facilitate termination at 88% of the 1400 identified intrinsic terminators. Our results indicate that NusG stimulates a sequence-specific pause that assists in the completion of suboptimal terminator hairpins with weak terminal A-U and G-U base pairs at the bottom of the stem. Loss of NusA and NusG leads to global misregulation of gene expression and loss of NusG results in flagella and swimming motility defects.
Collapse
Affiliation(s)
- Zachary F Mandell
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Reid T Oshiro
- Department of Biology, Indiana UniversityBloomingtonUnited States
| | - Alexander V Yakhnin
- NCI RNA Biology Laboratory, Center for Cancer Research, NCIFrederickUnited States
| | - Rishi Vishwakarma
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| | - Mikhail Kashlev
- NCI RNA Biology Laboratory, Center for Cancer Research, NCIFrederickUnited States
| | - Daniel B Kearns
- Department of Biology, Indiana UniversityBloomingtonUnited States
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, Pennsylvania State UniversityUniversity ParkUnited States
| |
Collapse
|
83
|
Lee J, Lee M, Lee K. Trans-acting regulators of ribonuclease activity. J Microbiol 2021; 59:341-359. [PMID: 33779951 DOI: 10.1007/s12275-021-0650-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 12/28/2020] [Accepted: 12/28/2020] [Indexed: 12/16/2022]
Abstract
RNA metabolism needs to be tightly regulated in response to changes in cellular physiology. Ribonucleases (RNases) play an essential role in almost all aspects of RNA metabolism, including processing, degradation, and recycling of RNA molecules. Thus, living systems have evolved to regulate RNase activity at multiple levels, including transcription, post-transcription, post-translation, and cellular localization. In addition, various trans-acting regulators of RNase activity have been discovered in recent years. This review focuses on the physiological roles and underlying mechanisms of trans-acting regulators of RNase activity.
Collapse
Affiliation(s)
- Jaejin Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Minho Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
| |
Collapse
|
84
|
Christopoulou N, Granneman S. The role of RNA-binding proteins in mediating adaptive responses in Gram-positive bacteria. FEBS J 2021; 289:1746-1764. [PMID: 33690958 DOI: 10.1111/febs.15810] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 02/06/2023]
Abstract
Bacteria are constantly subjected to stressful conditions, such as antibiotic exposure, nutrient limitation and oxidative stress. For pathogenic bacteria, adapting to the host environment, escaping defence mechanisms and coping with antibiotic stress are crucial for their survival and the establishment of a successful infection. Stress adaptation relies heavily on the rate at which the organism can remodel its gene expression programme to counteract the stress. RNA-binding proteins mediating co- and post-transcriptional regulation have recently emerged as important players in regulating gene expression during adaptive responses. Most of the research on these layers of gene expression regulation has been done in Gram-negative model organisms where, thanks to a wide variety of global studies, large post-transcriptional regulatory networks have been uncovered. Unfortunately, our understanding of post-transcriptional regulation in Gram-positive bacteria is lagging behind. One possible explanation for this is that many proteins employed by Gram-negative bacteria are not well conserved in Gram-positives. And even if they are conserved, they do not always play similar roles as in Gram-negative bacteria. This raises the important question whether Gram-positive bacteria regulate gene expression in a significantly different way. The goal of this review was to discuss this in more detail by reviewing the role of well-known RNA-binding proteins in Gram-positive bacteria and by highlighting their different behaviours with respect to some of their Gram-negative counterparts. Finally, the second part of this review introduces several unusual RNA-binding proteins of Gram-positive species that we believe could also play an important role in adaptive responses.
Collapse
Affiliation(s)
- Niki Christopoulou
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, UK
| | - Sander Granneman
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, UK
| |
Collapse
|
85
|
Lee J, Lee M, Lee K. Trans-acting regulators of ribonuclease activity. J Microbiol 2021:10.1007/s12275-021-0650-3. [PMID: 33565052 DOI: 10.1007/s12275-021-0650-3] [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: 12/11/2020] [Revised: 12/28/2020] [Accepted: 12/28/2020] [Indexed: 11/29/2022]
Abstract
RNA metabolism needs to be tightly regulated in response to changes in cellular physiology. Ribonucleases (RNases) play an essential role in almost all aspects of RNA metabolism, including processing, degradation, and recycling of RNA molecules. Thus, living systems have evolved to regulate RNase activity at multiple levels, including transcription, post-transcription, post-translation, and cellular localization. In addition, various trans-acting regulators of RNase activity have been discovered in recent years. This review focuses on the physiological roles and underlying mechanisms of trans-acting regulators of RNase activity.
Collapse
Affiliation(s)
- Jaejin Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea
| | - Minho Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Seoul, 06974, Republic of Korea.
| |
Collapse
|
86
|
Spanka DT, Reuscher CM, Klug G. Impact of PNPase on the transcriptome of Rhodobacter sphaeroides and its cooperation with RNase III and RNase E. BMC Genomics 2021; 22:106. [PMID: 33549057 PMCID: PMC7866481 DOI: 10.1186/s12864-021-07409-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/26/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The polynucleotide phosphorylase (PNPase) is conserved among both Gram-positive and Gram-negative bacteria. As a core part of the Escherichia coli degradosome, PNPase is involved in maintaining proper RNA levels within the bacterial cell. It plays a major role in RNA homeostasis and decay by acting as a 3'-to-5' exoribonuclease. Furthermore, PNPase can catalyze the reverse reaction by elongating RNA molecules in 5'-to-3' end direction which has a destabilizing effect on the prolonged RNA molecule. RNA degradation is often initiated by an endonucleolytic cleavage, followed by exoribonucleolytic decay from the new 3' end. RESULTS The PNPase mutant from the facultative phototrophic Rhodobacter sphaeroides exhibits several phenotypical characteristics, including diminished adaption to low temperature, reduced resistance to organic peroxide induced stress and altered growth behavior. The transcriptome composition differs in the pnp mutant strain, resulting in a decreased abundance of most tRNAs and rRNAs. In addition, PNPase has a major influence on the half-lives of several regulatory sRNAs and can have both a stabilizing or a destabilizing effect. Moreover, we globally identified and compared differential RNA 3' ends in RNA NGS sequencing data obtained from PNPase, RNase E and RNase III mutants for the first time in a Gram-negative organism. The genome wide RNA 3' end analysis revealed that 885 3' ends are degraded by PNPase. A fair percentage of these RNA 3' ends was also identified at the same genomic position in RNase E or RNase III mutant strains. CONCLUSION The PNPase has a major influence on RNA processing and maturation and thus modulates the transcriptome of R. sphaeroides. This includes sRNAs, emphasizing the role of PNPase in cellular homeostasis and its importance in regulatory networks. The global 3' end analysis indicates a sequential RNA processing: 5.9% of all RNase E-dependent and 9.7% of all RNase III-dependent RNA 3' ends are subsequently degraded by PNPase. Moreover, we provide a modular pipeline which greatly facilitates the identification of RNA 5'/3' ends. It is publicly available on GitHub and is distributed under ICS license.
Collapse
Affiliation(s)
- Daniel-Timon Spanka
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Giessen, Germany
| | - Carina Maria Reuscher
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Giessen, Germany
| | - Gabriele Klug
- Institute of Microbiology and Molecular Biology, Justus Liebig University Giessen, IFZ, Giessen, Germany.
| |
Collapse
|
87
|
Workman RE, Pammi T, Nguyen BTK, Graeff LW, Smith E, Sebald SM, Stoltzfus MJ, Euler CW, Modell JW. A natural single-guide RNA repurposes Cas9 to autoregulate CRISPR-Cas expression. Cell 2021; 184:675-688.e19. [PMID: 33421369 DOI: 10.1016/j.cell.2020.12.017] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 09/24/2020] [Accepted: 12/09/2020] [Indexed: 12/11/2022]
Abstract
CRISPR-Cas systems provide prokaryotes with acquired immunity against viruses and plasmids, but how these systems are regulated to prevent autoimmunity is poorly understood. Here, we show that in the S. pyogenes CRISPR-Cas system, a long-form transactivating CRISPR RNA (tracr-L) folds into a natural single guide that directs Cas9 to transcriptionally repress its own promoter (Pcas). Further, we demonstrate that Pcas serves as a critical regulatory node. De-repression causes a dramatic 3,000-fold increase in immunization rates against viruses; however, heightened immunity comes at the cost of increased autoimmune toxicity. Using bioinformatic analyses, we provide evidence that tracrRNA-mediated autoregulation is widespread in type II-A CRISPR-Cas systems. Collectively, we unveil a new paradigm for the intrinsic regulation of CRISPR-Cas systems by natural single guides, which may facilitate the frequent horizontal transfer of these systems into new hosts that have not yet evolved their own regulatory strategies.
Collapse
Affiliation(s)
- Rachael E Workman
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Teja Pammi
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Binh T K Nguyen
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Leonardo W Graeff
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Erika Smith
- Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Suzanne M Sebald
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Marie J Stoltzfus
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Chad W Euler
- Department of Medical Laboratory Sciences, Hunter College, CUNY, New York, NY 10065, USA; Department of Microbiology and Immunology, Weill Cornell Medicine, New York, NY 10065, USA
| | - Joshua W Modell
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
88
|
Lee M, Ryu M, Joo M, Seo YJ, Lee J, Kim HM, Shin E, Yeom JH, Kim YH, Bae J, Lee K. Endoribonuclease-mediated control of hns mRNA stability constitutes a key regulatory pathway for Salmonella Typhimurium pathogenicity island 1 expression. PLoS Pathog 2021; 17:e1009263. [PMID: 33524062 PMCID: PMC7877770 DOI: 10.1371/journal.ppat.1009263] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 02/11/2021] [Accepted: 01/01/2021] [Indexed: 01/04/2023] Open
Abstract
Bacteria utilize endoribonuclease-mediated RNA processing and decay to rapidly adapt to environmental changes. Here, we report that the modulation of hns mRNA stability by the endoribonuclease RNase G plays a key role in Salmonella Typhimurium pathogenicity. We found that RNase G determines the half-life of hns mRNA by cleaving its 5′ untranslated region and that altering its cleavage sites by genome editing stabilizes hns mRNA, thus decreasing S. Typhimurium virulence in mice. Under anaerobic conditions, the FNR-mediated transcriptional repression of rnc encoding RNase III, which degrades rng mRNA, and simultaneous induction of rng transcription resulted in rapid hns mRNA degradation, leading to the derepression of genes involved in the Salmonella pathogenicity island 1 (SPI-1) type III secretion system (T3SS). Together, our findings show that RNase III and RNase G levels-mediated control of hns mRNA abundance acts as a regulatory pathway upstream of a complex feed-forward loop for SPI-1 expression. Recent studies have shown that pathogenic bacteria with ribonuclease mutations display attenuated virulence, impaired mobility, and reduced proliferation in host cells. However, the molecular mechanisms underlying ribonuclease-associated pathogenesis have not yet been characterised. Here, we provide strong experimental evidence that the coordinated modulation of endoribonuclease activity constitutes an additional regulatory layer upstream of a complex feed-forward loop controlling global regulatory systems in the Salmonella pathogenicity island 1 (SPI-1) type III secretion system (T3SS). In addition, we showed that this regulatory pathway plays a key role in the virulence of S. Typhimurium in the host. Thus, our study improves the understanding of the mechanisms through which bacterial pathogens sense the host environment and respond precisely by expressing gene products required for adaptation to that particular niche.
Collapse
Affiliation(s)
- Minho Lee
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Minkyung Ryu
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Minju Joo
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Young-Jin Seo
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Jaejin Lee
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Hong-Man Kim
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Eunkyoung Shin
- Department of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Ji-Hyun Yeom
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
| | - Yong-Hak Kim
- Department of Microbiology, Daegu Catholic University School of Medicine, Daegu, Republic of Korea
- * E-mail: (Y-HK); (JB); (KL)
| | - Jeehyeon Bae
- Department of Pharmacy, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
- * E-mail: (Y-HK); (JB); (KL)
| | - Kangseok Lee
- Department of Life Science, Chung-Ang University, Dongjak-Gu, Seoul, Republic of Korea
- * E-mail: (Y-HK); (JB); (KL)
| |
Collapse
|
89
|
Ingle S, Chhabra S, Laspina D, Salvo E, Liu B, Bechhofer DH. Polynucleotide phosphorylase and RNA helicase CshA cooperate in Bacillus subtilis mRNA decay. RNA Biol 2020; 18:1692-1701. [PMID: 33323028 DOI: 10.1080/15476286.2020.1864183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
Polynucleotide phosphorylase (PNPase), a 3' exoribonuclease that degrades RNA in the 3'-to-5' direction, is the major mRNA decay activity in Bacillus subtilis. PNPase is known to be inhibited in vitro by strong RNA secondary structure, and rapid mRNA turnover in vivo is thought to require an RNA helicase activity working in conjunction with PNPase. The most abundant RNA helicase in B. subtilis is CshA. We found for three small, monocistronic mRNAs that, for some RNA sequences, PNPase processivity was unimpeded even without CshA, whereas others required CshA for efficient degradation. A novel colour screen for decay of mRNA in B. subtilis was created, using mRNA encoded by the slrA gene, which is degraded from its 3' end by PNPase. A significant correlation between the predicted strength of a stem-loop structure, located in the body of the message, and PNPase processivity was observed. Northern blot analysis confirmed that PNPase processivity was greatly hindered by the internal RNA structure, and even more so in the absence of CshA. Three other B. subtilis RNA helicases did not appear to be involved in mRNA decay during vegetative growth. The results confirm the hypothesis that efficient 3' exonucleolytic decay of B. subtilis RNA depends on the combined activity of PNPase and CshA.
Collapse
Affiliation(s)
- Shakti Ingle
- Icahn School of Medicine at Mount Sinai, Department of Pharmacological Sciences, New York, NY, USA
| | - Shivani Chhabra
- Icahn School of Medicine at Mount Sinai, Department of Pharmacological Sciences, New York, NY, USA
| | - Denise Laspina
- Icahn School of Medicine at Mount Sinai, Department of Pharmacological Sciences, New York, NY, USA
| | - Elizabeth Salvo
- Icahn School of Medicine at Mount Sinai, Department of Pharmacological Sciences, New York, NY, USA
| | - Bo Liu
- Icahn School of Medicine at Mount Sinai, Department of Pharmacological Sciences, New York, NY, USA
| | - David H Bechhofer
- Icahn School of Medicine at Mount Sinai, Department of Pharmacological Sciences, New York, NY, USA
| |
Collapse
|
90
|
Samuels DS, Lybecker MC, Yang XF, Ouyang Z, Bourret TJ, Boyle WK, Stevenson B, Drecktrah D, Caimano MJ. Gene Regulation and Transcriptomics. Curr Issues Mol Biol 2020; 42:223-266. [PMID: 33300497 DOI: 10.21775/cimb.042.223] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Borrelia (Borreliella) burgdorferi, along with closely related species, is the etiologic agent of Lyme disease. The spirochete subsists in an enzootic cycle that encompasses acquisition from a vertebrate host to a tick vector and transmission from a tick vector to a vertebrate host. To adapt to its environment and persist in each phase of its enzootic cycle, B. burgdorferi wields three systems to regulate the expression of genes: the RpoN-RpoS alternative sigma factor cascade, the Hk1/Rrp1 two-component system and its product c-di-GMP, and the stringent response mediated by RelBbu and DksA. These regulatory systems respond to enzootic phase-specific signals and are controlled or fine- tuned by transcription factors, including BosR and BadR, as well as small RNAs, including DsrABb and Bb6S RNA. In addition, several other DNA-binding and RNA-binding proteins have been identified, although their functions have not all been defined. Global changes in gene expression revealed by high-throughput transcriptomic studies have elucidated various regulons, albeit technical obstacles have mostly limited this experimental approach to cultivated spirochetes. Regardless, we know that the spirochete, which carries a relatively small genome, regulates the expression of a considerable number of genes required for the transitions between the tick vector and the vertebrate host as well as the adaptation to each.
Collapse
Affiliation(s)
- D Scott Samuels
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Meghan C Lybecker
- Department of Biology, University of Colorado, Colorado Springs, CO 80918, USA
| | - X Frank Yang
- Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Zhiming Ouyang
- Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Travis J Bourret
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, 68105 USA
| | - William K Boyle
- Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE, 68105 USA
| | - Brian Stevenson
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky School of Medicine, Lexington, KY 40536, USA
| | - Dan Drecktrah
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Melissa J Caimano
- Departments of Medicine, Pediatrics, and Molecular Biology and Biophysics, UConn Health, Farmington, CT, USA
| |
Collapse
|
91
|
Enhanced Symbiotic Characteristics in Bacterial Genomes with the Disruption of rRNA Operon. BIOLOGY 2020; 9:biology9120440. [PMID: 33287185 PMCID: PMC7761764 DOI: 10.3390/biology9120440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/11/2020] [Accepted: 12/01/2020] [Indexed: 11/18/2022]
Abstract
Simple Summary Exploring the genomic changes that organisms have undergone to adapt to their specific environment is one of the most important processes in ecology and evolutionary biology. Here, we found that almost all rRNA operon-unlinked bacteria are symbiotic bacteria, which could be evidence of specific selective pressures in symbionts like genome reduction. This is meaningful and suggests that not only does the copy number variation of the rRNA operon sensitively respond to the bacterial lifestyle, but structural modification can also strongly reflect adaptation to the surrounding environmental conditions. Abstract Ribosomal RNA is an indispensable molecule in living organisms that plays an essential role in protein synthesis. Especially in bacteria, 16S, 23S, and 5S rRNAs are usually co-transcribed as operons. Despite the positive effects of rRNA co-transcription on growth and reproduction rate, a recent study revealed that bacteria with unlinked rRNA operons are more widespread than expected. However, it is still unclear why the rRNA operon is broken. Here, we explored rRNA operon linkage status in 15,898 bacterial genomes and investigated whether they have common features or lifestyles; 574 genomes were found to have unlinked rRNA operons and tended to be phylogenetically conserved. Most of them were symbionts and showed enhanced symbiotic genomic features such as reduced genome size and high adenine–thymine (AT) content. In an eggNOG-mapper analysis, they were also found to have significantly fewer genes than rRNA operon-linked bacteria in the “transcription” and “energy production and conversion in metabolism” categories. These genomes also tend to decrease RNases related to the synthesis of ribosomes and tRNA processing. Based on these results, the disruption of the rRNA operon seems to be one of the tendencies associated with the characteristics of bacteria requiring a low dynamic range.
Collapse
|
92
|
Maksimov IV, Sorokan AV, Shein MY, Khairullin RM. Biological Methods of Plant Protection against Viruses: Problems and Prospects. APPL BIOCHEM MICRO+ 2020. [DOI: 10.1134/s0003683820060101] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
93
|
Pavankumar TL, Mittal P, Hallsworth JE. Molecular insights into the ecology of a psychrotolerant
Pseudomonas syringae. Environ Microbiol 2020; 23:3665-3681. [DOI: 10.1111/1462-2920.15304] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/01/2020] [Accepted: 11/03/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Theetha L. Pavankumar
- Department of Microbiology and Molecular Genetics, Briggs Hall, One Shields Avenue University of California Davis CA USA
| | - Pragya Mittal
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine University of Edinburgh Crewe Road South, Edinburgh, EH42XU, Scotland UK
| | - John E. Hallsworth
- Institute for Global Food Security, School of Biological Sciences Queen's University Belfast 19 Chlorine Gardens, Belfast, BT9 5DL Northern Ireland UK
| |
Collapse
|
94
|
Fernández-Coll L, Cashel M. Possible Roles for Basal Levels of (p)ppGpp: Growth Efficiency Vs. Surviving Stress. Front Microbiol 2020; 11:592718. [PMID: 33162969 PMCID: PMC7581894 DOI: 10.3389/fmicb.2020.592718] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 09/16/2020] [Indexed: 11/18/2022] Open
Abstract
Two (p)ppGpp nucleotide analogs, sometimes abbreviated simply as ppGpp, are widespread in bacteria and plants. Their name alarmone reflects a view of their function as intracellular hormone-like protective alarms that can increase a 100-fold when sensing any of an array of physical or nutritional dangers, such as abrupt starvation, that trigger lifesaving adjustments of global gene expression and physiology. The diversity of mechanisms for stress-specific adjustments of this sort is large and further compounded by almost infinite microbial diversity. The central question raised by this review is whether the small basal levels of (p)ppGpp functioning during balanced growth serve very different roles than alarmone-like functions. Recent discoveries that abrupt amino acid starvation of Escherichia coli, accompanied by very high levels of ppGpp, occasion surprising instabilities of transfer RNA (tRNA), ribosomal RNA (rRNA), and ribosomes raises new questions. Is this destabilization, a mode of regulation linearly related to (p)ppGpp over the entire continuum of (p)ppGpp levels, including balanced growth? Are regulatory mechanisms exerted by basal (p)ppGpp levels fundamentally different than for high levels? There is evidence from studies of other organisms suggesting special regulatory features of basal levels compared to burst of (p)ppGpp. Those differences seem to be important even during bacterial infection, suggesting that unbalancing the basal levels of (p)ppGpp may become a future antibacterial treatment. A simile for this possible functional duality is that (p)ppGpp acts like a car’s brake, able to stop to avoid crashes as well as to slow down to drive safely.
Collapse
Affiliation(s)
- Llorenç Fernández-Coll
- Intramural Research Program, Eunice Kennedy Shriver NICHD, NIH, Bethesda, MD, United States
| | - Michael Cashel
- Intramural Research Program, Eunice Kennedy Shriver NICHD, NIH, Bethesda, MD, United States
| |
Collapse
|
95
|
Vargas-Blanco DA, Shell SS. Regulation of mRNA Stability During Bacterial Stress Responses. Front Microbiol 2020; 11:2111. [PMID: 33013770 PMCID: PMC7509114 DOI: 10.3389/fmicb.2020.02111] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
Bacteria have a remarkable ability to sense environmental changes, swiftly regulating their transcriptional and posttranscriptional machinery as a response. Under conditions that cause growth to slow or stop, bacteria typically stabilize their transcriptomes in what has been shown to be a conserved stress response. In recent years, diverse studies have elucidated many of the mechanisms underlying mRNA degradation, yet an understanding of the regulation of mRNA degradation under stress conditions remains elusive. In this review we discuss the diverse mechanisms that have been shown to affect mRNA stability in bacteria. While many of these mechanisms are transcript-specific, they provide insight into possible mechanisms of global mRNA stabilization. To that end, we have compiled information on how mRNA fate is affected by RNA secondary structures; interaction with ribosomes, RNA binding proteins, and small RNAs; RNA base modifications; the chemical nature of 5' ends; activity and concentration of RNases and other degradation proteins; mRNA and RNase localization; and the stringent response. We also provide an analysis of reported relationships between mRNA abundance and mRNA stability, and discuss the importance of stress-associated mRNA stabilization as a potential target for therapeutic development.
Collapse
Affiliation(s)
- Diego A Vargas-Blanco
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, United States
| | - Scarlet S Shell
- Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, MA, United States.,Program in Bioinformatics and Computational Biology, Worcester Polytechnic Institute, Worcester, MA, United States
| |
Collapse
|
96
|
Das A, Dasgupta S, Pathak T. Design of configuration-restricted triazolylated β-d-ribofuranosides: a unique family of crescent-shaped RNase A inhibitors. Org Biomol Chem 2020; 18:6340-6356. [PMID: 32766618 DOI: 10.1039/d0ob01286f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Seven new carbohydrate-bistriazole hybrid molecules were designed taking into consideration the crescent shaped active site of ribonuclease A (RNase A). In this case, the β-d-ribofuranose structure was used as the basic building unit; both the C1 and C4 arms protruding out towards the β-face of the tetrahydrofuran moiety of the ribose sugar provided an overall "U" shape to the basic building block. Several combinations of bistriazole moieties were constructed on the two arms of this basic building block. These mono- and/or bis-substituted 1,2,3-triazole units were linked to acidic functional groups because of the overall basic nature of the hydrolytic site of RNase A. All these compounds were efficient competitive inhibitors of RNase A with inhibition constants (Ki) in the micromolar range. In contrast to the carboxylic acid-modified hybrid molecules, molecules carrying sulfonic acids were found to be more potent because of the stronger interactions with the positively charged active site. The most efficient inhibitor of the series was the disulfonic acid-functionalized carbohydrate-bis-triazole hybrid molecule. Docking studies disclosed that the molecule, because of its well defined "U" shape with flexible arms, fits effectively in the active site; moreover, in all cases, besides the acid groups, the triazole and sugar rings also actively participated in creating the hydrogen bonding network in the cavity of the enzyme active site.
Collapse
Affiliation(s)
- Ashrukana Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India.
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India.
| | - Tanmaya Pathak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, West Bengal, India.
| |
Collapse
|
97
|
Jain C. RNase AM, a 5' to 3' exonuclease, matures the 5' end of all three ribosomal RNAs in E. coli. Nucleic Acids Res 2020; 48:5616-5623. [PMID: 32343306 PMCID: PMC7261194 DOI: 10.1093/nar/gkaa260] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 03/30/2020] [Accepted: 04/09/2020] [Indexed: 10/31/2022] Open
Abstract
Bacterial ribosomal RNAs (rRNAs) are transcribed as precursors and require processing by Ribonucleases (RNases) to generate mature and functional rRNAs. Although the initial steps of rRNA processing in Escherichia coli (E. coli) were described several decades ago, the enzymes responsible for the final steps of 5S and 23S rRNA 5'-end maturation have remained unknown. Here, I show that RNase AM, a recently identified 5' to 3' exonuclease, performs the last step of 5S rRNA 5'-end maturation. RNase AM was also found to generate the mature 5' end of 23S rRNA, subsequent to a newly identified prior processing step. Additionally, RNase AM was found to mature the 5' end of 16S rRNA, a reaction previously attributed to RNase G. These findings indicate a major role for RNase AM in cellular RNA metabolism and establish a biological role for the first 5' to 3' RNA exonuclease identified in E. coli.
Collapse
Affiliation(s)
- Chaitanya Jain
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| |
Collapse
|
98
|
Hoyos M, Huber M, Förstner KU, Papenfort K. Gene autoregulation by 3' UTR-derived bacterial small RNAs. eLife 2020; 9:58836. [PMID: 32744240 PMCID: PMC7398697 DOI: 10.7554/elife.58836] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/23/2020] [Indexed: 01/01/2023] Open
Abstract
Negative feedback regulation, that is the ability of a gene to repress its own synthesis, is the most abundant regulatory motif known to biology. Frequently reported for transcriptional regulators, negative feedback control relies on binding of a transcription factor to its own promoter. Here, we report a novel mechanism for gene autoregulation in bacteria relying on small regulatory RNA (sRNA) and the major endoribonuclease, RNase E. TIER-seq analysis (transiently-inactivating-an-endoribonuclease-followed-by-RNA-seq) revealed ~25,000 RNase E-dependent cleavage sites in Vibrio cholerae, several of which resulted in the accumulation of stable sRNAs. Focusing on two examples, OppZ and CarZ, we discovered that these sRNAs are processed from the 3' untranslated region (3' UTR) of the oppABCDF and carAB operons, respectively, and base-pair with their own transcripts to inhibit translation. For OppZ, this process also triggers Rho-dependent transcription termination. Our data show that sRNAs from 3' UTRs serve as autoregulatory elements allowing negative feedback control at the post-transcriptional level.
Collapse
Affiliation(s)
- Mona Hoyos
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.,Faculty of Biology I, Ludwig-Maximilians-University of Munich, Martinsried, Germany
| | - Michaela Huber
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.,Faculty of Biology I, Ludwig-Maximilians-University of Munich, Martinsried, Germany
| | - Konrad U Förstner
- TH Köln - University of Applied Sciences, Institute of Information Science, Cologne, Germany.,ZB MED - Information Centre for Life Sciences, Cologne, Germany
| | - Kai Papenfort
- Friedrich Schiller University Jena, Institute of Microbiology, Jena, Germany.,Faculty of Biology I, Ludwig-Maximilians-University of Munich, Martinsried, Germany.,Microverse Cluster, Friedrich Schiller University Jena, Jena, Germany
| |
Collapse
|
99
|
Erber L, Hoffmann A, Fallmann J, Hagedorn M, Hammann C, Stadler PF, Betat H, Prohaska S, Mörl M. Unusual Occurrence of Two Bona-Fide CCA-Adding Enzymes in Dictyostelium discoideum. Int J Mol Sci 2020; 21:ijms21155210. [PMID: 32717856 PMCID: PMC7432833 DOI: 10.3390/ijms21155210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 01/12/2023] Open
Abstract
Dictyostelium discoideum, the model organism for the evolutionary supergroup of Amoebozoa, is a social amoeba that, upon starvation, undergoes transition from a unicellular to a multicellular organism. In its genome, we identified two genes encoding for tRNA nucleotidyltransferases. Such pairs of tRNA nucleotidyltransferases usually represent collaborating partial activities catalyzing CC- and A-addition to the tRNA 3'-end, respectively. In D. discoideum, however, both enzymes exhibit identical activities, representing bona-fide CCA-adding enzymes. Detailed characterization of the corresponding activities revealed that both enzymes seem to be essential and are regulated inversely during different developmental stages of D. discoideum. Intriguingly, this is the first description of two functionally equivalent CCA-adding enzymes using the same set of tRNAs and showing a similar distribution within the cell. This situation seems to be a common feature in Dictyostelia, as other members of this phylum carry similar pairs of tRNA nucleotidyltransferase genes in their genome.
Collapse
Affiliation(s)
- Lieselotte Erber
- Institute for Biochemistry, University of Leipzig, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (H.B.)
| | - Anne Hoffmann
- Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany; (A.H.); (J.F.); (P.F.S.); (S.P.)
| | - Jörg Fallmann
- Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany; (A.H.); (J.F.); (P.F.S.); (S.P.)
| | - Monica Hagedorn
- Ribogenetics Biochemistry Lab, Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany; (M.H.); (C.H.)
| | - Christian Hammann
- Ribogenetics Biochemistry Lab, Department of Life Sciences and Chemistry, Jacobs University Bremen gGmbH, Campus Ring 1, 28759 Bremen, Germany; (M.H.); (C.H.)
| | - Peter F. Stadler
- Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany; (A.H.); (J.F.); (P.F.S.); (S.P.)
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Competence Center for Scalable Data Services and Solutions, and Leipzig Research Center for Civilization Diseases, Leipzig University, 04103 Leipzig, Germany
- Max Planck Institute for Mathematics in the Sciences, 04103 Leipzig, Germany
- Facultad de Ciencias, Universidad National de Colombia, Sede Bogotá, Carrera 45 No. 26-85, Colombia
- Santa Fe Institute for Complex Systems, 1399 Hyde Park Road, Santa Fe, NM 87501, USA
- Department of Theoretical Chemistry of the University of Vienna, A-1090 Vienna, Austria
| | - Heike Betat
- Institute for Biochemistry, University of Leipzig, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (H.B.)
| | - Sonja Prohaska
- Interdisciplinary Center for Bioinformatics, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany; (A.H.); (J.F.); (P.F.S.); (S.P.)
- Computational EvoDevo Group, Department of Computer Science, Leipzig University, Härtelstraße 16-18, 04107 Leipzig, Germany
| | - Mario Mörl
- Institute for Biochemistry, University of Leipzig, Brüderstraße 34, 04103 Leipzig, Germany; (L.E.); (H.B.)
- Correspondence: ; Tel.: +49-341-9736-911; Fax: +49-341-9736-919
| |
Collapse
|
100
|
Dudkina EV, Ulyanova VV, Ilinskaya ON. Supramolecular Organization As a Factor of Ribonuclease Cytotoxicity. Acta Naturae 2020; 12:24-33. [PMID: 33173594 PMCID: PMC7604891 DOI: 10.32607/actanaturae.11000] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Accepted: 06/29/2020] [Indexed: 11/28/2022] Open
Abstract
One of the approaches used to eliminate tumor cells is directed destruction/modification of their RNA molecules. In this regard, ribonucleases (RNases) possess a therapeutic potential that remains largely unexplored. It is believed that the biological effects of secreted RNases, namely their antitumor and antiviral properties, derive from their catalytic activity. However, a number of recent studies have challenged the notion that the activity of RNases in the manifestation of selective cytotoxicity towards cancer cells is exclusively an enzymatic one. In this review, we have analyzed available data on the cytotoxic effects of secreted RNases, which are not associated with their catalytic activity, and we have provided evidence that the most important factor in the selective apoptosis-inducing action of RNases is the structural organization of these enzymes, which determines how they interact with cell components. The new idea on the preponderant role of non-catalytic interactions between RNases and cancer cells in the manifestation of selective cytotoxicity will contribute to the development of antitumor RNase-based drugs.
Collapse
Affiliation(s)
- E. V. Dudkina
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, 420008 Russia
| | - V. V. Ulyanova
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, 420008 Russia
| | - O. N. Ilinskaya
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, 420008 Russia
| |
Collapse
|