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Uppalapati S, Kant S, Liu L, Kim JS, Orlicky D, McClelland M, Vazquez-Torres A. Prophage terminase with tRNase activity sensitizes Salmonella enterica to oxidative stress. Science 2024; 384:100-105. [PMID: 38574144 DOI: 10.1126/science.adl3222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/28/2024] [Indexed: 04/06/2024]
Abstract
Phage viruses shape the evolution and virulence of their bacterial hosts. The Salmonella enterica genome encodes several stress-inducible prophages. The Gifsy-1 prophage terminase protein, whose canonical function is to process phage DNA for packaging in the virus head, unexpectedly acts as a transfer ribonuclease (tRNase) under oxidative stress, cleaving the anticodon loop of tRNALeu. The ensuing RNA fragmentation compromises bacterial translation, intracellular survival, and recovery from oxidative stress in the vertebrate host. S. enterica adapts to this transfer RNA (tRNA) fragmentation by transcribing the RNA repair Rtc system. The counterintuitive translational arrest provided by tRNA cleavage may subvert prophage mobilization and give the host an opportunity for repair as a way of maintaining bacterial genome integrity and ultimately survival in animals.
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Affiliation(s)
- Siva Uppalapati
- University of Colorado School of Medicine, Department of Immunology and Microbiology, Aurora, CO, USA
| | - Sashi Kant
- University of Colorado School of Medicine, Department of Immunology and Microbiology, Aurora, CO, USA
| | - Lin Liu
- University of Colorado School of Medicine, Department of Immunology and Microbiology, Aurora, CO, USA
| | - Ju-Sim Kim
- University of Colorado School of Medicine, Department of Immunology and Microbiology, Aurora, CO, USA
| | - David Orlicky
- University of Colorado School of Medicine, Department of Pathology, Aurora, CO, USA
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California Irvine School of Medicine, Irvine, CA, USA
| | - Andres Vazquez-Torres
- University of Colorado School of Medicine, Department of Immunology and Microbiology, Aurora, CO, USA
- Veterans Affairs Eastern Colorado Health Care System, Denver, CO, USA
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2
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Abstract
Oxidative stress is an important and pervasive physical stress encountered by all kingdoms of life, including bacteria. In this review, we briefly describe the nature of oxidative stress, highlight well-characterized protein-based sensors (transcription factors) of reactive oxygen species that serve as standards for molecular sensors in oxidative stress, and describe molecular studies that have explored the potential of direct RNA sensitivity to oxidative stress. Finally, we describe the gaps in knowledge of RNA sensors-particularly regarding the chemical modification of RNA nucleobases. RNA sensors are poised to emerge as an essential layer of understanding and regulating dynamic biological pathways in oxidative stress responses in bacteria and, thus, also represent an important frontier of synthetic biology.
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Affiliation(s)
- Ryan Buchser
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Phillip Sweet
- Integrative Life Sciences Program, University of Texas at Austin, Austin, Texas, USA
| | - Aparna Anantharaman
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
| | - Lydia Contreras
- McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, Texas, USA;
- Integrative Life Sciences Program, University of Texas at Austin, Austin, Texas, USA
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3
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Ponzetti M, Rucci N, Falone S. RNA methylation and cellular response to oxidative stress-promoting anticancer agents. Cell Cycle 2023; 22:870-905. [PMID: 36648057 PMCID: PMC10054233 DOI: 10.1080/15384101.2023.2165632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 01/03/2023] [Indexed: 01/18/2023] Open
Abstract
Disruption of the complex network that regulates redox homeostasis often underlies resistant phenotypes, which hinder effective and long-lasting cancer eradication. In addition, the RNA methylome-dependent control of gene expression also critically affects traits of cellular resistance to anti-cancer agents. However, few investigations aimed at establishing whether the epitranscriptome-directed adaptations underlying acquired and/or innate resistance traits in cancer could be implemented through the involvement of redox-dependent or -responsive signaling pathways. This is unexpected mainly because: i) the effectiveness of many anti-cancer approaches relies on their capacity to promote oxidative stress (OS); ii) altered redox milieu and reprogramming of mitochondrial function have been acknowledged as critical mediators of the RNA methylome-mediated response to OS. Here we summarize the current state of understanding on this topic, as well as we offer new perspectives that might lead to original approaches and strategies to delay or prevent the problem of refractory cancer and tumor recurrence.
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Affiliation(s)
- Marco Ponzetti
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L'Aquila, Italy
| | - Nadia Rucci
- Department of Biotechnological and Applied Clinical Sciences, University of L’Aquila, L'Aquila, Italy
| | - Stefano Falone
- Department of Life, Health and Environmental Sciences, University of L’Aquila, L’Aquila, Italy
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tRNAs Are Stable After All: Pitfalls in Quantification of tRNA from Starved Escherichia coli Cultures Exposed by Validation of RNA Purification Methods. mBio 2023; 14:e0280522. [PMID: 36598190 PMCID: PMC9973347 DOI: 10.1128/mbio.02805-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
tRNAs and ribosomal RNAs are often considered stable RNAs. In contrast to this view, we recently proposed that tRNAs are degraded during amino acid starvation and drug-induced transcription inhibition. However, reevaluation of our experimental approach revealed that common RNA extraction methods suffer from alarming extraction and size biases that can lead to gross underestimation of RNA levels in starved Escherichia coli populations. Quantification of tRNAs suffers additional biases due to differing fractions of tRNAs with base modifications in growing versus starved bacteria. Applying an improved methodology, we measured tRNA levels after starvation for amino acids, glucose, phosphate, or ammonium and transcription inhibition by rifampicin. We report that tRNA levels remain largely unaffected in all tested conditions, including several days of starvation. This confirms that tRNAs are remarkably stable RNAs and serves as a cautionary tale about quantification of RNA from cells cultured outside the steady-state growth regime. rRNA, conversely, is extensively degraded during starvation. Thus, E. coli downregulates the translation machinery in response to starvation by reducing the ribosome pool through rRNA degradation, while a high concentration of tRNAs available to supply amino acids to the remaining ribosomes is maintained. IMPORTANCE We show that E. coli tRNAs are remarkably stable during several days of nutrient starvation, although rRNA is degraded extensively under these conditions. The levels of these two major RNA classes are considered to be strongly coregulated at the level of transcription. We demonstrate that E. coli can control the ratio of tRNAs per ribosome under starvation by means of differential degradation rates. The question of tRNA stability in stressed E. coli cells has become subject to debate. Our in-depth analysis of RNA quantification methods reveals hidden technical pitfalls at every step of the analysis, from RNA extraction to target detection and normalization. Most importantly, starved E. coli populations were more resilient to RNA extraction than unstarved populations. The current results underscore that the seemingly trivial task of quantifying an abundant RNA species is not straightforward for cells cultured outside the exponential growth regime.
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Han L, Luo Z, Ju Y, Chen B, Zou T, Wang J, Xu J, Gu Q, Yang XL, Schimmel P, Zhou H. The binding mode of orphan glycyl-tRNA synthetase with tRNA supports the synthetase classification and reveals large domain movements. SCIENCE ADVANCES 2023; 9:eadf1027. [PMID: 36753552 PMCID: PMC9908026 DOI: 10.1126/sciadv.adf1027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Accepted: 01/06/2023] [Indexed: 06/18/2023]
Abstract
As a class of essential enzymes in protein translation, aminoacyl-transfer RNA (tRNA) synthetases (aaRSs) are organized into two classes of 10 enzymes each, based on two conserved active site architectures. The (αβ)2 glycyl-tRNA synthetase (GlyRS) in many bacteria is an orphan aaRS whose sequence and unprecedented X-shaped structure are distinct from those of all other aaRSs, including many other bacterial and all eukaryotic GlyRSs. Here, we report a cocrystal structure to elucidate how the orphan GlyRS kingdom specifically recognizes its substrate tRNA. This structure is sharply different from those of other aaRS-tRNA complexes but conforms to the clash-free, cross-class aaRS-tRNA docking found with conventional structures and reinforces the class-reconstruction paradigm. In addition, noteworthy, the X shape of orphan GlyRS is condensed with the largest known spatial rearrangement needed by aaRSs to capture tRNAs, which suggests potential nonactive site targets for aaRS-directed antibiotics, instead of less differentiated hard-to-drug active site locations.
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Affiliation(s)
- Lu Han
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Zhiteng Luo
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Yingchen Ju
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Bingyi Chen
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Taotao Zou
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Junjian Wang
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Jun Xu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Qiong Gu
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
| | - Xiang-Lei Yang
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Paul Schimmel
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Huihao Zhou
- Guangdong Provincial Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
- Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, China
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Jiao L, Liu Y, Yu XY, Pan X, Zhang Y, Tu J, Song YH, Li Y. Ribosome biogenesis in disease: new players and therapeutic targets. Signal Transduct Target Ther 2023; 8:15. [PMID: 36617563 PMCID: PMC9826790 DOI: 10.1038/s41392-022-01285-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/01/2022] [Accepted: 12/08/2022] [Indexed: 01/10/2023] Open
Abstract
The ribosome is a multi-unit complex that translates mRNA into protein. Ribosome biogenesis is the process that generates ribosomes and plays an essential role in cell proliferation, differentiation, apoptosis, development, and transformation. The mTORC1, Myc, and noncoding RNA signaling pathways are the primary mediators that work jointly with RNA polymerases and ribosome proteins to control ribosome biogenesis and protein synthesis. Activation of mTORC1 is required for normal fetal growth and development and tissue regeneration after birth. Myc is implicated in cancer development by enhancing RNA Pol II activity, leading to uncontrolled cancer cell growth. The deregulation of noncoding RNAs such as microRNAs, long noncoding RNAs, and circular RNAs is involved in developing blood, neurodegenerative diseases, and atherosclerosis. We review the similarities and differences between eukaryotic and bacterial ribosomes and the molecular mechanism of ribosome-targeting antibiotics and bacterial resistance. We also review the most recent findings of ribosome dysfunction in COVID-19 and other conditions and discuss the consequences of ribosome frameshifting, ribosome-stalling, and ribosome-collision. We summarize the role of ribosome biogenesis in the development of various diseases. Furthermore, we review the current clinical trials, prospective vaccines for COVID-19, and therapies targeting ribosome biogenesis in cancer, cardiovascular disease, aging, and neurodegenerative disease.
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Affiliation(s)
- Lijuan Jiao
- grid.263761.70000 0001 0198 0694Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu 215123 P. R. China
| | - Yuzhe Liu
- grid.452829.00000000417660726Department of Orthopedics, the Second Hospital of Jilin University, Changchun, Jilin 130000 P. R. China
| | - Xi-Yong Yu
- grid.410737.60000 0000 8653 1072Key Laboratory of Molecular Target & Clinical Pharmacology and the NMPA State Key Laboratory of Respiratory Disease, Guangzhou Medical University, Guangzhou, Guangdong 511436 P. R. China
| | - Xiangbin Pan
- grid.506261.60000 0001 0706 7839Department of Structural Heart Disease, National Center for Cardiovascular Disease, China & Fuwai Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, P. R. China ,Key Laboratory of Cardiovascular Appratus Innovation, Beijing, 100037 P. R. China
| | - Yu Zhang
- grid.263761.70000 0001 0198 0694Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu 215123 P. R. China
| | - Junchu Tu
- grid.263761.70000 0001 0198 0694Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu 215123 P. R. China
| | - Yao-Hua Song
- Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, National Clinical Research Center for Hematologic Diseases, the First Affiliated Hospital of Soochow University, Suzhou, P. R. China. .,State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, P. R. China.
| | - Yangxin Li
- Institute for Cardiovascular Science and Department of Cardiovascular Surgery, First Affiliated Hospital and Medical College of Soochow University, Collaborative Innovation Center of Hematology, Soochow University, Suzhou, Jiangsu, 215123, P. R. China.
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Sreelatha S, Kumar N, Rajani S. Biological effects of Thymol loaded chitosan nanoparticles (TCNPs) on bacterial plant pathogen Xanthomonas campestris pv. campestris. Front Microbiol 2022; 13:1085113. [PMID: 36620059 PMCID: PMC9815552 DOI: 10.3389/fmicb.2022.1085113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Engineered nanomaterials can provide eco-friendly alternatives for crop disease management. Chitosan based nanoparticles has shown beneficial applications in sustainable agricultural practices and effective healthcare. Previously we demonstrated that Thymol loaded chitosan nanoparticles (TCNPs) showed bactericidal activity against Xanthomonas campestris pv campestris (Xcc), a bacterium that causes black rot disease in brassica crops. Despite the progress in assessing the antibacterial action of TCNPs, the knowledge about the molecular response of Xcc when exposed to TCNPs is yet to be explored. In the present study, we combined physiological, spectroscopic and untargeted metabolomics studies to investigate the response mechanisms in Xcc induced by TCNPs. Cell proliferation and membrane potential assays of Xcc cells exposed to sub-lethal concentration of TCNPs showed that TCNPs affects the cell proliferation rate and damages the cell membrane altering the membrane potential. FTIR spectroscopy in conjunction with untargeted metabolite profiling using mass spectrometry of TCNPs treated Xcc cells revealed alterations in amino acids, lipids, nucleotides, fatty acids and antioxidant metabolites. Mass spectroscopy analysis revealed a 10-25% increase in nucleic acid, fatty acids and antioxidant metabolites and a 20% increase in lipid metabolites while a decrease of 10-20% in amino acids and carbohydrates was seen in in TCNP treated Xcc cells. Overall, our results demonstrate that the major metabolic perturbations induced by TCNPs in Xcc are associated with membrane damage and oxidative stress, thus providing information on the mechanism of TCNPs mediated cytotoxicity. This will aid towards the development of nano- based agrochemicals as an alternative to chemical pesticides in future.
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Leiva LE, Elgamal S, Leidel SA, Orellana O, Ibba M, Katz A. Oxidative stress strongly restricts the effect of codon choice on the efficiency of protein synthesis in Escherichia coli. Front Microbiol 2022; 13:1042675. [DOI: 10.3389/fmicb.2022.1042675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/04/2022] [Indexed: 11/30/2022] Open
Abstract
IntroductionThe response of enterobacteria to oxidative stress is usually considered to be regulated by transcription factors such as OxyR and SoxR. Nevertheless, several reports have shown that under oxidative stress the levels, modification and aminoacylation of tRNAs may be altered suggesting a role of codon bias in regulation of gene expression under this condition.MethodsIn order to characterize the effects of oxidative stress on translation elongation we constructed a library of 61 plasmids, each coding for the green fluorescent protein (GFP) translationally fused to a different set of four identical codons.ResultsUsing these reporters, we observed that GFP production levels vary widely (~15 fold) when Escherichia coli K-12 is cultured in minimal media as a consequence of codon choice variations. When bacteria are cultured under oxidative stress caused by paraquat the levels of GFP produced by most clones is reduced and, in contrast to control conditions, the range of GFP levels is restricted to a ~2 fold range. Restricting elongation of particular sequences does not increase the range of GFP production under oxidative stress, but altering translation initiation rates leads to an increase in this range.DiscussionAltogether, our results suggest that under normal conditions the speed of translation elongation is in the range of the speed of initiation and, consequently, codon choice impacts the speed of protein synthesis. In contrast, under oxidative stress translation initiation becomes much slower than elongation, limiting the speed of translation such that codon choice has at most only subtle effects on the overall output of translation.
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Seixas AF, Quendera AP, Sousa JP, Silva AFQ, Arraiano CM, Andrade JM. Bacterial Response to Oxidative Stress and RNA Oxidation. Front Genet 2022; 12:821535. [PMID: 35082839 PMCID: PMC8784731 DOI: 10.3389/fgene.2021.821535] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Accepted: 12/21/2021] [Indexed: 01/03/2023] Open
Abstract
Bacteria have to cope with oxidative stress caused by distinct Reactive Oxygen Species (ROS), derived not only from normal aerobic metabolism but also from oxidants present in their environments. The major ROS include superoxide O2−, hydrogen peroxide H2O2 and radical hydroxide HO•. To protect cells under oxidative stress, bacteria induce the expression of several genes, namely the SoxRS, OxyR and PerR regulons. Cells are able to tolerate a certain number of free radicals, but high levels of ROS result in the oxidation of several biomolecules. Strikingly, RNA is particularly susceptible to this common chemical damage. Oxidation of RNA causes the formation of strand breaks, elimination of bases or insertion of mutagenic lesions in the nucleobases. The most common modification is 8-hydroxyguanosine (8-oxo-G), an oxidized form of guanosine. The structure and function of virtually all RNA species (mRNA, rRNA, tRNA, sRNA) can be affected by RNA oxidation, leading to translational defects with harmful consequences for cell survival. However, bacteria have evolved RNA quality control pathways to eliminate oxidized RNA, involving RNA-binding proteins like the members of the MutT/Nudix family and the ribonuclease PNPase. Here we summarize the current knowledge on the bacterial stress response to RNA oxidation, namely we present the different ROS responsible for this chemical damage and describe the main strategies employed by bacteria to fight oxidative stress and control RNA damage.
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Affiliation(s)
- André F Seixas
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana P Quendera
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - João P Sousa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Alda F Q Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Cecília M Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - José M Andrade
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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10
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Margalit A, Carolan JC, Walsh F. Global protein responses of multi-drug resistant plasmid containing Escherichia coli to ampicillin, cefotaxime, imipenem and ciprofloxacin. J Glob Antimicrob Resist 2021; 28:90-96. [PMID: 34922055 DOI: 10.1016/j.jgar.2021.12.006] [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: 10/26/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVES This study compared the proteomics of Escherichia coli containing the multi-drug resistance pEK499 plasmid under antimicrobial stress and no antimicrobial. METHODS We utilised mass spectrometry-based proteomics to compare the proteomes of the bacteria and plasmid under antimicrobial stress and no antimicrobial. RESULTS Our analysis identified statistically significant differentially abundant proteins common to groups exposed to the β-lactam antimicrobials but not ciprofloxacin, indicating a β-lactam stress response to exposure from this class of drugs, irrespective of β-lactam resistance or susceptibility. Data arising from comparisons of the proteomes of ciprofloxacin-treated E. coli and controls detected an increase in the relative abundance of proteins associated with ribosomes, translation, the TCA-cycle and several proteins associated with detoxification and a decrease in the relative abundances of proteins associated with stress response, including oxidative stress. We identified changes in proteins associated with persister formation in the presence of ciprofloxacin but not the β-lactams. The plasmid proteome differed across each treatment and did not follow the pattern of antimicrobial - AMR protein associations: a relative increase in the amount of blaCTX-M-15 in the presence of cefotaxime and ciprofloxacin but not the other β-lactams, suggesting regulation of the blaCTX-M-15 protein production. CONCLUSIONS The proteomic data from the this study provided novel insights into the proteins produced from the chromosome and plasmid under different antimicrobial stresses. These data also identified novel proteins not previously associated with AMR or antimicrobials responses in pathogens, which may well represent potential targets of AMR inhibition.
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Affiliation(s)
- Anatte Margalit
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - James C Carolan
- Department of Biology, Maynooth University, Co. Kildare, Ireland
| | - Fiona Walsh
- Department of Biology, Maynooth University, Co. Kildare, Ireland.
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11
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Estevez M, Valesyan S, Jora M, Limbach PA, Addepalli B. Oxidative Damage to RNA is Altered by the Presence of Interacting Proteins or Modified Nucleosides. Front Mol Biosci 2021; 8:697149. [PMID: 34277707 PMCID: PMC8281250 DOI: 10.3389/fmolb.2021.697149] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 06/21/2021] [Indexed: 12/15/2022] Open
Abstract
Oxidative stress triggered by the Fenton reaction (chemical) or UVR exposure (photo) can damage cellular biomolecules including RNA through oxidation of nucleotides. Besides such xenobiotic chemical modifications, RNA also contains several post-transcriptional nucleoside modifications that are installed by enzymes to modulate structure, RNA-protein interactions, and biochemical functions. We examined the extent of oxidative damage to naturally modified RNA which is required for cellular protein synthesis under two different contexts. The extent of oxidative damage is higher when RNA is not associated with proteins, but the degree of damage is lower when the RNA is presented in the form of a ribonucleoprotein complex, such as an intact ribosome. Our studies also indicate that absence of methylations in ribosomal RNA at specific positions could make it more susceptible to photooxidative stress. However, the extent of guanosine oxidation varied with the position at which the modification is deficient, indicating position-dependent structural effects. Further, an E. coli strain deficient in 5-methylaminomethyl-2-thiouridine (mnm5s2U) (found in lysine and glutamate tRNA anticodon) is more vulnerable to oxidative RNA damage compared to its wildtype strain suggesting an auxiliary function for the mnm5s2U modification. These studies indicate that oxidative damage to RNA is altered by the presence of enzymatic modified nucleosides or protein association inside the cell.
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Affiliation(s)
- Mariana Estevez
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, United States
| | - Satenik Valesyan
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, United States
| | - Manasses Jora
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, United States
| | - Patrick A Limbach
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, United States
| | - Balasubrahmanyam Addepalli
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, Cincinnati, OH, United States
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12
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Fasnacht M, Polacek N. Oxidative Stress in Bacteria and the Central Dogma of Molecular Biology. Front Mol Biosci 2021; 8:671037. [PMID: 34041267 PMCID: PMC8141631 DOI: 10.3389/fmolb.2021.671037] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/26/2021] [Indexed: 11/13/2022] Open
Abstract
Ever since the "great oxidation event," Earth's cellular life forms had to cope with the danger of reactive oxygen species (ROS) affecting the integrity of biomolecules and hampering cellular metabolism circuits. Consequently, increasing ROS levels in the biosphere represented growing stress levels and thus shaped the evolution of species. Whether the ROS were produced endogenously or exogenously, different systems evolved to remove the ROS and repair the damage they inflicted. If ROS outweigh the cell's capacity to remove the threat, we speak of oxidative stress. The injuries through oxidative stress in cells are diverse. This article reviews the damage oxidative stress imposes on the different steps of the central dogma of molecular biology in bacteria, focusing in particular on the RNA machines involved in transcription and translation.
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Affiliation(s)
- Michel Fasnacht
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Norbert Polacek
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
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