1
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Eleftheraki A, Holmqvist E. An RNA pseudoknot mediates toxin translation and antitoxin inhibition. Proc Natl Acad Sci U S A 2024; 121:e2403063121. [PMID: 38935561 PMCID: PMC11228461 DOI: 10.1073/pnas.2403063121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 06/03/2024] [Indexed: 06/29/2024] Open
Abstract
Type I toxin-antitoxin systems (T1TAs) are bipartite bacterial loci encoding a growth-inhibitory toxin and an antitoxin small RNA (sRNA). In many of these systems, the transcribed toxin mRNA is translationally inactive, but becomes translation-competent upon ribonucleolytic processing. The antitoxin sRNA targets the processed mRNA to inhibit its translation. This two-level control mechanism prevents cotranscriptional translation of the toxin and allows its synthesis only when the antitoxin is absent. Contrary to this, we found that the timP mRNA of the timPR T1TA locus does not undergo enzymatic processing. Instead, the full-length timP transcript is both translationally active and can be targeted by the antitoxin TimR. Thus, tight control in this system relies on a noncanonical mechanism. Based on the results from in vitro binding assays, RNA structure probing, and cell-free translation experiments, we suggest that timP mRNA adopts mutually exclusive structural conformations. The active form uniquely possesses an RNA pseudoknot structure which is essential for translation initiation. TimR preferentially binds to the active conformation, which leads to pseudoknot destabilization and inhibited translation. Based on this, we propose a model in which "structural processing" of timP mRNA enables tight inhibition by TimR in nonpermissive conditions, and TimP synthesis only upon TimR depletion.
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Affiliation(s)
- Athina Eleftheraki
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala75124, Sweden
- Uppsala Antibiotic Center, Uppsala University, Uppsala75123, Sweden
| | - Erik Holmqvist
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala75124, Sweden
- Uppsala Antibiotic Center, Uppsala University, Uppsala75123, Sweden
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2
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Chernyshov SV, Masulis IS, Mikoulinskaia GV. From DNA to lytic proteins: transcription and translation of the bacteriophage T5 holin/endolysin operon. World J Microbiol Biotechnol 2024; 40:256. [PMID: 38926173 DOI: 10.1007/s11274-024-04063-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 06/23/2024] [Indexed: 06/28/2024]
Abstract
The analysis of transcriptional activity of the bacteriophage T5 hol/endo operon conducted in the paper revealed a strong constitutive promoter recognized by E. coli RNA polymerase and a transcription initiation point of the operon. It was also shown that the only translational start codon for holin was a non-canonical TTG. Translation initiation regions (TIRs) of both genes of the operon (hol and endo) were further analyzed using chimeric constructs, in which parts of the hol/endo regulatory regions were fused with the gene of a reporter protein (EGFP). It was found that TIR of hol was 20 times less effective than that of endo. As it turned out, the level of EGFP production was influenced by the composition of the constructs and the type of the hol start codon. Apparently, the translational suppression of holin's accumulation and posttranslational activation of endolysin by Ca2+ are the main factors ensuring the proper timing of the host cell lysis by bacteriophage T5. The approach based on the use of chimeric constructs proposed in the paper can be recommended for studying other native or artificial operons of any complexity: analyzing the impacts of separate DNA regions, as well as their coupled effect, on the processes of transcription and translation of recombinant protein(s).
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Affiliation(s)
- Sergei V Chernyshov
- Branch of Shemyakin & Ovchinnikov's Institute of Bioorganic Chemistry RAS, Prospekt Nauki, 6, Pushchino, Moscow region, Pushchino, Moscow region, 142290, Russia
| | - Irina S Masulis
- Institute of Cell Biophysics RAS PBC RAS, Institutskaya ul., 3, Pushchino, Pushchino, Moscow region, 142290, Russia
| | - Galina V Mikoulinskaia
- Branch of Shemyakin & Ovchinnikov's Institute of Bioorganic Chemistry RAS, Prospekt Nauki, 6, Pushchino, Moscow region, Pushchino, Moscow region, 142290, Russia.
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3
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Arbib C, D'ascenzo A, Rossi F, Santoni D. An Integer Linear Programming Model to Optimize Coding DNA Sequences By Joint Control of Transcript Indicators. J Comput Biol 2024; 31:416-428. [PMID: 38687334 DOI: 10.1089/cmb.2023.0166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024] Open
Abstract
A Coding DNA Sequence (CDS) is a fraction of DNA whose nucleotides are grouped into consecutive triplets called codons, each one encoding an amino acid. Because most amino acids can be encoded by more than one codon, the same amino acid chain can be obtained by a very large number of different CDSs. These synonymous CDSs show different features that, also depending on the organism the transcript is expressed in, could affect translational efficiency and yield. The identification of optimal CDSs with respect to given transcript indicators is in general a challenging task, but it has been observed in recent literature that integer linear programming (ILP) can be a very flexible and efficient way to achieve it. In this article, we add evidence to this observation by proposing a new ILP model that simultaneously optimizes different well-grounded indicators. With this model, we efficiently find solutions that dominate those returned by six existing codon optimization heuristics.
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Affiliation(s)
- Claudio Arbib
- Department of Information Engineering, Computer Science, and Mathematics University of L'Aquila, L'Aquila, Italy
| | - Andrea D'ascenzo
- Department of Information Engineering, Computer Science, and Mathematics University of L'Aquila, L'Aquila, Italy
| | - Fabrizio Rossi
- Department of Information Engineering, Computer Science, and Mathematics University of L'Aquila, L'Aquila, Italy
| | - Daniele Santoni
- Institute for System Analysis and Computer Science Antonio Ruberti National Research Council of Italy, Rome, Italy
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4
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Ali F. Patterns of Change in Nucleotide Diversity Over Gene Length. Genome Biol Evol 2024; 16:evae078. [PMID: 38608148 PMCID: PMC11040516 DOI: 10.1093/gbe/evae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 03/26/2024] [Accepted: 04/03/2024] [Indexed: 04/14/2024] Open
Abstract
Nucleotide diversity at a site is influenced by the relative strengths of neutral and selective population genetic processes. Therefore, attempts to estimate Effective population size based on the diversity of synonymous sites demand a better understanding of their selective constraints. The nucleotide diversity of a gene was previously found to correlate with its length. In this work, I measure nucleotide diversity at synonymous sites and uncover a pattern of low diversity towards the translation initiation site of a gene. The degree of reduction in diversity at the translation initiation site and the length of this region of reduced diversity can be quantified as "Effect Size" and "Effect Length" respectively, using parameters of an asymptotic regression model. Estimates of Effect Length across bacteria covaried with recombination rates as well as with a multitude of translation-associated traits such as the avoidance of mRNA secondary structure around translation initiation site, the number of rRNAs, and relative codon usage of ribosomal genes. Evolutionary simulations under purifying selection reproduce the observed patterns and diversity-length correlation and highlight that selective constraints on the 5'-region of a gene may be more extensive than previously believed. These results have implications for the estimation of effective population size, and relative mutation rates, and for genome scans of genes under positive selection based on "silent-site" diversity.
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Affiliation(s)
- Farhan Ali
- Biodesign Center for Mechanisms of Evolution, Arizona State University, Tempe, AZ 85281, USA
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5
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Sun M, Gao AX, Li A, Ledesma-Amaro R, Wang P, Chen W, Bai Z, Liu X. Hyper-production of porcine contagious pleuropneumonia subunit vaccine proteins in Escherichia coli by developing a bicistronic T7 expression system. Biotechnol J 2024; 19:e2300187. [PMID: 38178735 DOI: 10.1002/biot.202300187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 12/15/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024]
Abstract
The ApxII toxin and the outer membrane lipoprotein (Oml) of Actinobacillus pleuropneumoniae are important vaccine antigens against porcine contagious pleuropneumonia (PCP), a prevalent infectious disease affecting the swine industry worldwide. Previous studies have reported the recombinant expression of ApxII and Oml in Escherichia coli; however, their yields were not satisfactory. Here, we aimed to enhance the production of ApxII and Oml by constructing a bicistronic expression system based on the widely used T7 promoter. To create efficient T7 bicistronic expression cassettes, 16 different fore-cistron sequences were introduced downstream of the T7 promoter. The expression of three vaccine antigens Oml1, Oml7, and ApxII in the four strongest bicistronic vectors were enhanced compared to the monocistronic control. Further optimization of the fermentation conditions in micro-well plates (MWP) led to improved production. Finally, the production yields reached unprecedented levels of 2.43 g L-1 of Oml1, 2.59 g L-1 of Oml7, and 1.21 g L-1 of ApxII, in a 5 L bioreactor. These three antigens also demonstrated well-protective immunity against A. pleuropneumoniae infection. In conclusion, this study establishes an efficient bicistronic T7 expression system that can be used to express recombinant proteins in E. coli and achieves the hyper-production of PCP vaccine proteins.
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Affiliation(s)
- Manman Sun
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London, UK
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Alex Xiong Gao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - An Li
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Rodrigo Ledesma-Amaro
- Department of Bioengineering and Imperial College Centre for Synthetic Biology, Imperial College London, London, UK
| | - Peng Wang
- Key Laboratory of High Magnetic Field and Ion Beam Physical Biology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Wenchao Chen
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, Hubei, China
| | - Zhonghu Bai
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
| | - Xiuxia Liu
- National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi, China
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6
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Lux MW, Strychalski EA, Vora GJ. Advancing reproducibility can ease the 'hard truths' of synthetic biology. Synth Biol (Oxf) 2023; 8:ysad014. [PMID: 38022744 PMCID: PMC10640854 DOI: 10.1093/synbio/ysad014] [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: 03/07/2023] [Revised: 07/26/2023] [Accepted: 10/04/2023] [Indexed: 12/01/2023] Open
Abstract
Reproducibility has been identified as an outstanding challenge in science, and the field of synthetic biology is no exception. Meeting this challenge is critical to allow the transformative technological capabilities emerging from this field to reach their full potential to benefit the society. We discuss the current state of reproducibility in synthetic biology and how improvements can address some of the central shortcomings in the field. We argue that the successful adoption of reproducibility as a routine aspect of research and development requires commitment spanning researchers and relevant institutions via education, incentivization and investment in related infrastructure. The urgency of this topic pervades synthetic biology as it strives to advance fundamental insights and unlock new capabilities for safe, secure and scalable applications of biotechnology. Graphical Abstract.
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Affiliation(s)
- Matthew W Lux
- Research & Operations Directorate, U.S. Army Combat Capabilities Development Command Chemical Biological Center, APG, MD 21010, USA
| | - Elizabeth A Strychalski
- Cellular Engineering Group, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
| | - Gary J Vora
- Center for Bio/Molecular Science & Engineering, U.S. Naval Research Laboratory, Washington, DC 20375, USA
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7
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Hara K, Iwano N, Fukunaga T, Hamada M. DeepRaccess: high-speed RNA accessibility prediction using deep learning. FRONTIERS IN BIOINFORMATICS 2023; 3:1275787. [PMID: 37881622 PMCID: PMC10597636 DOI: 10.3389/fbinf.2023.1275787] [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: 08/10/2023] [Accepted: 09/29/2023] [Indexed: 10/27/2023] Open
Abstract
RNA accessibility is a useful RNA secondary structural feature for predicting RNA-RNA interactions and translation efficiency in prokaryotes. However, conventional accessibility calculation tools, such as Raccess, are computationally expensive and require considerable computational time to perform transcriptome-scale analysis. In this study, we developed DeepRaccess, which predicts RNA accessibility based on deep learning methods. DeepRaccess was trained to take artificial RNA sequences as input and to predict the accessibility of these sequences as calculated by Raccess. Simulation and empirical dataset analyses showed that the accessibility predicted by DeepRaccess was highly correlated with the accessibility calculated by Raccess. In addition, we confirmed that DeepRaccess could predict protein abundance in E.coli with moderate accuracy from the sequences around the start codon. We also demonstrated that DeepRaccess achieved tens to hundreds of times software speed-up in a GPU environment. The source codes and the trained models of DeepRaccess are freely available at https://github.com/hmdlab/DeepRaccess.
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Affiliation(s)
- Kaisei Hara
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Computational Bio Big-Data Open Innovation Laboratory, AIST-Waseda University, Tokyo, Japan
| | - Natsuki Iwano
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
| | - Tsukasa Fukunaga
- Waseda Institute for Advanced Study, Waseda University, Tokyo, Japan
| | - Michiaki Hamada
- Department of Electrical Engineering and Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, Tokyo, Japan
- Computational Bio Big-Data Open Innovation Laboratory, AIST-Waseda University, Tokyo, Japan
- Graduate School of Medicine, Nippon Medical School, Tokyo, Japan
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8
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Lewin LE, Daniels KG, Hurst LD. Genes for highly abundant proteins in Escherichia coli avoid 5' codons that promote ribosomal initiation. PLoS Comput Biol 2023; 19:e1011581. [PMID: 37878567 PMCID: PMC10599525 DOI: 10.1371/journal.pcbi.1011581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/09/2023] [Indexed: 10/27/2023] Open
Abstract
In many species highly expressed genes (HEGs) over-employ the synonymous codons that match the more abundant iso-acceptor tRNAs. Bacterial transgene codon randomization experiments report, however, that enrichment with such "translationally optimal" codons has little to no effect on the resultant protein level. By contrast, consistent with the view that ribosomal initiation is rate limiting, synonymous codon usage following the 5' ATG greatly influences protein levels, at least in part by modifying RNA stability. For the design of bacterial transgenes, for simple codon based in silico inference of protein levels and for understanding selection on synonymous mutations, it would be valuable to computationally determine initiation optimality (IO) scores for codons for any given species. One attractive approach is to characterize the 5' codon enrichment of HEGs compared with the most lowly expressed genes, just as translational optimality scores of codons have been similarly defined employing the full gene body. Here we determine the viability of this approach employing a unique opportunity: for Escherichia coli there is both the most extensive protein abundance data for native genes and a unique large-scale transgene codon randomization experiment enabling objective definition of the 5' codons that cause, rather than just correlate with, high protein abundance (that we equate with initiation optimality, broadly defined). Surprisingly, the 5' ends of native genes that specify highly abundant proteins avoid such initiation optimal codons. We find that this is probably owing to conflicting selection pressures particular to native HEGs, including selection favouring low initiation rates, this potentially enabling high efficiency of ribosomal usage and low noise. While the classical HEG enrichment approach does not work, rendering simple prediction of native protein abundance from 5' codon content futile, we report evidence that initiation optimality scores derived from the transgene experiment may hold relevance for in silico transgene design for a broad spectrum of bacteria.
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Affiliation(s)
- Loveday E. Lewin
- The Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - Kate G. Daniels
- The Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath, United Kingdom
| | - Laurence D. Hurst
- The Milner Centre for Evolution, Department of Life Sciences, University of Bath, Bath, United Kingdom
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9
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Pivard M, Caldelari I, Brun V, Croisier D, Jaquinod M, Anzala N, Gilquin B, Teixeira C, Benito Y, Couzon F, Romby P, Moreau K, Vandenesch F. Complex Regulation of Gamma-Hemolysin Expression Impacts Staphylococcus aureus Virulence. Microbiol Spectr 2023; 11:e0107323. [PMID: 37347186 PMCID: PMC10434192 DOI: 10.1128/spectrum.01073-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 05/25/2023] [Indexed: 06/23/2023] Open
Abstract
Staphylococcus aureus gamma-hemolysin CB (HlgCB) is a core-genome-encoded pore-forming toxin that targets the C5a receptor, similar to the phage-encoded Panton-Valentine leucocidin (PVL). Absolute quantification by mass spectrometry of HlgCB in 39 community-acquired pneumonia (CAP) isolates showed considerable variations in the HlgC and HlgB yields between isolates. Moreover, although HlgC and HlgB are encoded on a single operon, their levels were dissociated in 10% of the clinical strains studied. To decipher the molecular basis for the variation in hlgCB expression and protein production among strains, different regulation levels were analyzed in representative clinical isolates and reference strains. Both the HlgCB level and the HlgC/HlgB ratio were found to depend on hlgC promoter activity and mRNA processing and translation. Strikingly, only one single nucleotide polymorphism (SNP) in the 5' untranslated region (UTR) of hlgCB mRNA strongly impaired hlgC translation in the USA300 strain, leading to a strong decrease in the level of HlgC but not in HlgB. Finally, we found that high levels of HlgCB synthesis led to mortality in a rabbit model of pneumonia, correlated with the implication of the role of HlgCB in severe S. aureus CAP. Taken together, this work illustrates the complexity of virulence factor expression in clinical strains and demonstrates a butterfly effect where subtle genomic variations have a major impact on phenotype and virulence. IMPORTANCE S. aureus virulence in pneumonia results in its ability to produce several virulence factors, including the leucocidin PVL. Here, we demonstrate that HlgCB, another leucocidin, which targets the same receptors as PVL, highly contributes to S. aureus virulence in pvl-negative strains. In addition, considerable variations in HlgCB quantities are observed among clinical isolates from patients with CAP. Biomolecular analyses have revealed that a few SNPs in the promoter sequences and only one SNP in the 5' UTR of hlgCB mRNA induce the differential expression of hlgCB, drastically impacting hlgC mRNA translation. This work illustrates the subtlety of regulatory mechanisms in bacteria, especially the sometimes major effects on phenotypes of single nucleotide variation in noncoding regions.
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Affiliation(s)
- Mariane Pivard
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France
| | - Isabelle Caldelari
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - Virginie Brun
- Université Grenoble Alpes, Inserm, CEA, UMR BioSanté U1292, CNRS, CEA, Grenoble, France
- Université Grenoble Alpes, CEA, LETI, Clinatec, Grenoble, France
| | | | - Michel Jaquinod
- Université Grenoble Alpes, Inserm, CEA, UMR BioSanté U1292, CNRS, CEA, Grenoble, France
| | | | - Benoît Gilquin
- Université Grenoble Alpes, Inserm, CEA, UMR BioSanté U1292, CNRS, CEA, Grenoble, France
- Université Grenoble Alpes, CEA, LETI, Clinatec, Grenoble, France
| | - Chloé Teixeira
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France
| | - Yvonne Benito
- Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
| | - Florence Couzon
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France
| | - Pascale Romby
- Architecture et Réactivité de l’ARN, Université de Strasbourg, CNRS, IBMC, Strasbourg, France
| | - Karen Moreau
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France
| | - François Vandenesch
- CIRI, Centre International de Recherche en Infectiologie, Université de Lyon, Inserm U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, Lyon, France
- Institut des Agents Infectieux, Hospices Civils de Lyon, Lyon, France
- Centre National de Référence des Staphylocoques, Hospices Civils de Lyon, Lyon, France
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10
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Ali F. Patterns of change in nucleotide diversity over gene length. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.13.548940. [PMID: 37503020 PMCID: PMC10369989 DOI: 10.1101/2023.07.13.548940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Nucleotide diversity at a site is influenced by the relative strengths of neutral and selective population genetic processes. Therefore, attempts to identify sites under positive selection require an understanding of the expected diversity in its absence. The nucleotide diversity of a gene was previously found to correlate with its length. In this work, I measure nucleotide diversity at synonymous sites and uncover a pattern of low diversity towards the translation initiation site (TIS) of a gene. The degree of reduction in diversity at the TIS and the length of this region of reduced diversity can be quantified as "Effect Size" and "Effect Length" respectively, using parameters of an asymptotic regression model. Estimates of Effect Length across bacteria covaried with recombination rates as well as with a multitude of fast-growth adaptations such as the avoidance of mRNA secondary structure around TIS, the number of rRNAs, and relative codon usage of ribosomal genes. Thus, the dependence of nucleotide diversity on gene length is governed by a combination of selective and non-selective processes. These results have implications for the estimation of effective population size and relative mutation rates based on "silent-site" diversity, and for pN/pS-based prediction of genes under selection.
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Affiliation(s)
- Farhan Ali
- Biodesign Institute, Arizona State University, Tempe, Arizona
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11
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Jansen Z, Reilly SR, Lieber-Kotz M, Li AZ, Wei Q, Kulhanek DL, Gilmour AR, Thyer R. Interrogating the Function of Bicistronic Translational Control Elements to Improve Consistency of Gene Expression. ACS Synth Biol 2023; 12:1608-1615. [PMID: 37253269 DOI: 10.1021/acssynbio.3c00093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Context independent gene expression is required for genetic circuits to maintain consistent and predicable behavior. Previous efforts to develop context independent translation have leveraged the helicase activity of translating ribosomes via bicistronic design translational control elements (BCDs) located within an efficiently translated leader peptide. We have developed a series of bicistronic translational control elements with strengths that span several orders of magnitude, maintain consistent expression levels across diverse sequence contexts, and are agnostic to common ligation sequences used in modular cloning systems. We have used this series of BCDs to investigate several features of this design, including the spacing of the start and stop codons, the nucleotide identity upstream of the start codon, and factors affecting translation of the leader peptide. To demonstrate the flexibility of this architecture and their value as a generic modular expression control cassette for synthetic biology, we have developed a set of robust BCDs for use in several Rhodococcus species.
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Affiliation(s)
- Zachary Jansen
- Systems, Synthetic, and Physical Biology, Rice University, Houston, Texas 77030, United States
| | - Sophia R Reilly
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77030, United States
| | - Matan Lieber-Kotz
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77030, United States
| | - Andrew Z Li
- Department of Statistics, Rice University, Houston, Texas 77030, United States
| | - Qiyao Wei
- Department of Bioengineering, Rice University, Houston, Texas 77030, United States
| | - Devon L Kulhanek
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77030, United States
| | - Andrew R Gilmour
- Systems, Synthetic, and Physical Biology, Rice University, Houston, Texas 77030, United States
| | - Ross Thyer
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas 77030, United States
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12
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Ghosh A, Bharmal MHM, Ghaleb AM, Nandana V, Schrader JM. Initiator AUGs Are Discriminated from Elongator AUGs Predominantly through mRNA Accessibility in C. crescentus. J Bacteriol 2023; 205:e0042022. [PMID: 37092987 PMCID: PMC10210977 DOI: 10.1128/jb.00420-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 03/27/2023] [Indexed: 04/25/2023] Open
Abstract
The initiation of translation in bacteria is thought to occur upon base pairing between the Shine-Dalgarno (SD) site in the mRNA and the anti-SD site in the rRNA. However, in many bacterial species, such as Caulobacter crescentus, a minority of mRNAs have SD sites. To examine the functional importance of SD sites in C. crescentus, we analyzed the transcriptome and found that more SD sites exist in the coding sequence than in the preceding start codons. To examine the function of SD sites in initiation, we designed a series of mutants with altered ribosome accessibility and SD content in translation initiation regions (TIRs) and in elongator AUG regions (EARs). A lack of mRNA structure content is required for initiation in TIRs, and, when introduced into EARs, can stimulate initiation, thereby suggesting that low mRNA structure content is a major feature that is required for initiation. SD sites appear to stimulate initiation in TIRs, which generally lack structure content, but SD sites only stimulate initiation in EARs if RNA secondary structures are destabilized. Taken together, these results suggest that the difference in secondary structure between TIRs and EARs directs ribosomes to start codons where SD base pairing can tune the efficiency of initiation, but SDs in EARs do not stimulate initiation, as they are blocked by stable secondary structures. This highlights the importance of studying translation initiation mechanisms in diverse bacterial species. IMPORTANCE Start codon selection is an essential process that is thought to occur via the base pairing of the rRNA to the SD site in the mRNA. This model is based on studies in E. coli, yet whole-genome sequencing revealed that SD sites are absent at start codons in many species. By examining the transcriptome of C. crescentus, we found more SD-AUG pairs in the CDS of mRNAs than preceding start codons, yet these internal sites do not initiate. Instead, start codon regions have lower mRNA secondary structure content than do internal SD-AUG regions. Therefore, we find that start codon selection is not controlled by the presence of SD sites, which tune initiation efficiency, but by lower mRNA structure content surrounding the start codon.
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Affiliation(s)
- Aishwarya Ghosh
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | | | - Amar M. Ghaleb
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Vidhyadhar Nandana
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Jared M. Schrader
- Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
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13
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Gonzalez-Sanchez B, Vega-Rodríguez MA, Santander-Jiménez S. A multi-objective butterfly optimization algorithm for protein encoding. Appl Soft Comput 2023. [DOI: 10.1016/j.asoc.2023.110269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
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14
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Picard MAL, Leblay F, Cassan C, Willemsen A, Daron J, Bauffe F, Decourcelle M, Demange A, Bravo IG. Transcriptomic, proteomic, and functional consequences of codon usage bias in human cells during heterologous gene expression. Protein Sci 2023; 32:e4576. [PMID: 36692287 PMCID: PMC9926478 DOI: 10.1002/pro.4576] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/12/2023] [Accepted: 01/14/2023] [Indexed: 01/25/2023]
Abstract
Differences in codon frequency between genomes, genes, or positions along a gene, modulate transcription and translation efficiency, leading to phenotypic and functional differences. Here, we present a multiscale analysis of the effects of synonymous codon recoding during heterologous gene expression in human cells, quantifying the phenotypic consequences of codon usage bias at different molecular and cellular levels, with an emphasis on translation elongation. Six synonymous versions of an antibiotic resistance gene were generated, fused to a fluorescent reporter, and independently expressed in HEK293 cells. Multiscale phenotype was analyzed by means of quantitative transcriptome and proteome assessment, as proxies for gene expression; cellular fluorescence, as a proxy for single-cell level expression; and real-time cell proliferation in absence or presence of antibiotic, as a proxy for the cell fitness. We show that differences in codon usage bias strongly impact the molecular and cellular phenotype: (i) they result in large differences in mRNA levels and protein levels, leading to differences of over 15 times in translation efficiency; (ii) they introduce unpredicted splicing events; (iii) they lead to reproducible phenotypic heterogeneity; and (iv) they lead to a trade-off between the benefit of antibiotic resistance and the burden of heterologous expression. In human cells in culture, codon usage bias modulates gene expression by modifying mRNA availability and suitability for translation, leading to differences in protein levels and eventually eliciting functional phenotypic changes.
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Affiliation(s)
- Marion A. L. Picard
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Fiona Leblay
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Cécile Cassan
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Anouk Willemsen
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Josquin Daron
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Frédérique Bauffe
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Mathilde Decourcelle
- BioCampus Montpellier (University of Montpellier, CNRS, INSERM)MontpellierFrance
| | - Antonin Demange
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
| | - Ignacio G. Bravo
- French National Center for Scientific ResearchLaboratory MIVEGEC (CNRS, IRD, University of Montpellier)MontpellierFrance
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15
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Dykeman EC. Modelling ribosome kinetics and translational control on dynamic mRNA. PLoS Comput Biol 2023; 19:e1010870. [PMID: 36689464 PMCID: PMC9894550 DOI: 10.1371/journal.pcbi.1010870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/02/2023] [Accepted: 01/10/2023] [Indexed: 01/24/2023] Open
Abstract
The control of protein synthesis and the overall levels of various proteins in the cell is critical for achieving homoeostasis. Regulation of protein levels can occur at the transcriptional level, where the total number of messenger RNAs in the overall transcriptome are controlled, or at the translational level, where interactions of proteins and ribosomes with the messenger RNA determine protein translational efficiency. Although transcriptional control of mRNA levels is the most commonly used regulatory control mechanism in cells, positive-sense single-stranded RNA viruses often utilise translational control mechanisms to regulate their proteins in the host cell. Here I detail a computational method for stochastically simulating protein synthesis on a dynamic messenger RNA using the Gillespie algorithm, where the mRNA is allowed to co-translationally fold in response to ribosome movement. Applying the model to the test case of the bacteriophage MS2 virus, I show that the models ability to accurately reproduce experimental measurements of coat protein production and translational repression of the viral RNA dependant RNA polymerase at high coat protein concentrations. The computational techniques reported here open up the potential to examine the infection dynamics of a ssRNA virus in a host cell at the level of the genomic RNA, as well as examine general translation control mechanisms present in polycistronic mRNAs.
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Affiliation(s)
- Eric C. Dykeman
- Department of Mathematics, University of York, York, United Kingdom
- * E-mail:
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16
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Song Y, Wang Y, Yan S, Nakamura K, Kikukawa T, Ayabe T, Aizawa T. Efficient recombinant production of mouse-derived cryptdin family peptides by a novel facilitation strategy for inclusion body formation. Microb Cell Fact 2023; 22:9. [PMID: 36635697 PMCID: PMC9838031 DOI: 10.1186/s12934-023-02016-2] [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: 01/01/2023] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND A number of antimicrobial peptides (AMPs) hold promise as new drugs owing to their potent bactericidal activity and because they are often refractory to the development of drug resistance. Cryptdins (Crps) are a family of antimicrobial peptides found in the small intestine of mice, comprising six isoforms containing three sets of disulfide bonds. Although Crp4 is actively being investigated, there have been few studies to date on the other Crp isoforms. A prerequisite for detailed characterization of the other Crp isoforms is establishment of efficient sample preparation methods. RESULTS To avoid degradation during recombinant expression of Crps in E. coli, co-expression of Crps with the aggregation-prone protein human α-lactalbumin (HLA) was used to promote the formation of stable inclusion bodies. Using this method, the production of Crp4 and Crp6 by the BL21 strain was effective, but the expression of other Crp isoforms was not as efficient. The results of a cell-free system study suggested that Crps were degraded, even though a substantial amounts of Crps were synthesized. Therefore, using the Origami™ B strain, we were able to significantly increase the expression efficiency of Crps by promoting the formation of erroneous intermolecular disulfide bonds between HLA and Crps, thereby promoting protein aggregation and inclusion body formation, which prevented degradation. The various Crp isoforms were successfully refolded in vitro and purified using reversed-phase HPLC. In addition, the yield was further improved by deformylation of formyl-Crps. We measured the antibacterial activity of Crps against both Gram-positive and Gram-negative bacteria. Each Crp isoform exhibited a completely different trend in antimicrobial activity, although conformational analysis by circular dichroism did not reveal any significant steric differences. CONCLUSION In this study, we established a novel and efficient method for the production of the cryptdin family of cysteine-containing antimicrobial peptides. Additionally, we found that there were notable differences in the antibacterial activities of the various Crp family members. The expression system established in this study is expected to provide new insights regarding the mechanisms underlying the different antibacterial activities of the Crp family of peptides.
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Affiliation(s)
- Yuchi Song
- grid.39158.360000 0001 2173 7691Laboratory of Protein Science, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
| | - Yi Wang
- grid.39158.360000 0001 2173 7691Laboratory of Protein Science, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
| | - Shaonan Yan
- grid.39158.360000 0001 2173 7691Laboratory of Protein Science, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
| | - Kiminori Nakamura
- grid.39158.360000 0001 2173 7691Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
| | - Takashi Kikukawa
- grid.39158.360000 0001 2173 7691Laboratory of Biological Information Analysis Science, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
| | - Tokiyoshi Ayabe
- grid.39158.360000 0001 2173 7691Innate Immunity Laboratory, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
| | - Tomoyasu Aizawa
- grid.39158.360000 0001 2173 7691Laboratory of Protein Science, Graduate School of Life Science, Hokkaido University, Sapporo, Hokkaido Japan
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17
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Li Y, Arce A, Lucci T, Rasmussen RA, Lucks JB. Dynamic RNA synthetic biology: new principles, practices and potential. RNA Biol 2023; 20:817-829. [PMID: 38044595 PMCID: PMC10730207 DOI: 10.1080/15476286.2023.2269508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 08/23/2023] [Indexed: 12/05/2023] Open
Abstract
An increased appreciation of the role of RNA dynamics in governing RNA function is ushering in a new wave of dynamic RNA synthetic biology. Here, we review recent advances in engineering dynamic RNA systems across the molecular, circuit and cellular scales for important societal-scale applications in environmental and human health, and bioproduction. For each scale, we introduce the core concepts of dynamic RNA folding and function at that scale, and then discuss technologies incorporating these concepts, covering new approaches to engineering riboswitches, ribozymes, RNA origami, RNA strand displacement circuits, biomaterials, biomolecular condensates, extracellular vesicles and synthetic cells. Considering the dynamic nature of RNA within the engineering design process promises to spark the next wave of innovation that will expand the scope and impact of RNA biotechnologies.
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Affiliation(s)
- Yueyi Li
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Anibal Arce
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Tyler Lucci
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
| | - Rebecca A. Rasmussen
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL, USA
| | - Julius B. Lucks
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL, USA
- Center for Synthetic Biology, Northwestern University, Evanston, IL, USA
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL, USA
- Center for Water Research, Northwestern University, Evanston, IL, USA
- Center for Engineering Sustainability and Resilience, Northwestern University, Evanston, IL, USA
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18
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Nicolet BP, Wolkers MC. The relationship of mRNA with protein expression in CD8+ T cells associates with gene class and gene characteristics. PLoS One 2022; 17:e0276294. [PMID: 36260607 PMCID: PMC9581405 DOI: 10.1371/journal.pone.0276294] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 10/04/2022] [Indexed: 11/19/2022] Open
Abstract
T cells are key players in our defence against infections and malignancies. When T cells differentiate or become activated, they undergo substantial alterations in gene expression. Even though RNA expression levels are now well documented throughout different stages of T cells, it is not well understood how mRNA expression translates into the protein landscape. By combining paired RNA sequencing and mass spectrometry data of primary human CD8+ T cells, we report that mRNA expression is a poor proxy for the overall protein output, irrespective of the differentiation or activation status. Yet, gene class stratification revealed a function-specific correlation of mRNA with protein expression. This gene class-specific expression pattern associated with differences in gene characteristics such as sequence conservation and untranslated region (UTR) lengths. In addition, the presence of AU-rich elements in the 3'UTR associated with alterations in mRNA and protein abundance T cell activation dependent, gene class-specific manner. In conclusion, our study highlights the role of gene characteristics as a determinant for gene expression in T cells.
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Affiliation(s)
- Benoît P. Nicolet
- Department of Hematopoiesis, Sanquin Research, Amsterdam, The Netherlands
- Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
| | - Monika C. Wolkers
- Department of Hematopoiesis, Sanquin Research, Amsterdam, The Netherlands
- Landsteiner Laboratory, Amsterdam UMC, University of Amsterdam, Amsterdam, The Netherlands
- Oncode Institute, Utrecht, The Netherlands
- * E-mail:
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19
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Komarova ES, Slesarchuk AN, Rubtsova MP, Osterman IA, Tupikin AE, Pyshnyi DV, Dontsova OA, Kabilov MR, Sergiev PV. Flow-Seq Evaluation of Translation Driven by a Set of Natural Escherichia coli 5'-UTR of Variable Length. Int J Mol Sci 2022; 23:ijms232012293. [PMID: 36293163 PMCID: PMC9604319 DOI: 10.3390/ijms232012293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Revised: 10/10/2022] [Accepted: 10/11/2022] [Indexed: 11/25/2022] Open
Abstract
Flow-seq is a method that combines fluorescently activated cell sorting and next-generation sequencing to deduce a large amount of data about translation efficiency from a single experiment. Here, we constructed a library of fluorescent protein-based reporters preceded by a set of 648 natural 5'-untranslated regions (5'-UTRs) of Escherichia coli genes. Usually, Flow-seq libraries are constructed using uniform-length sequence elements, in contrast to natural situations, where functional elements are of heterogenous lengths. Here, we demonstrated that a 5'-UTR library of variable length could be created and analyzed with Flow-seq. In line with previous Flow-seq experiments with randomized 5'-UTRs, we observed the influence of an RNA secondary structure and Shine-Dalgarno sequences on translation efficiency; however, the variability of these parameters for natural 5'-UTRs in our library was smaller in comparison with randomized libraries. In line with this, we only observed a 30-fold difference in translation efficiency between the best and worst bins sorted with this factor. The results correlated with those obtained with ribosome profiling.
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Affiliation(s)
- Ekaterina S. Komarova
- Institute of Functional Genomics, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Anna N. Slesarchuk
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Maria P. Rubtsova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Ilya A. Osterman
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, 143025 Moscow, Russia
| | - Alexey E. Tupikin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Dmitry V. Pyshnyi
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
| | - Olga A. Dontsova
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, 143025 Moscow, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 119992 Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
| | - Marsel R. Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Correspondence: (M.R.K.); (P.V.S.)
| | - Petr V. Sergiev
- Institute of Functional Genomics, Lomonosov Moscow State University, 119992 Moscow, Russia
- Department of Chemistry, Lomonosov Moscow State University, 119991 Moscow, Russia
- Center for Life Sciences, Skolkovo Institute of Science and Technology, Skolkovo, 143025 Moscow, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia
- Correspondence: (M.R.K.); (P.V.S.)
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20
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Hör J, Jung J, Ðurica-Mitić S, Barquist L, Vogel J. INRI-seq enables global cell-free analysis of translation initiation and off-target effects of antisense inhibitors. Nucleic Acids Res 2022; 50:e128. [PMID: 36229039 PMCID: PMC9825163 DOI: 10.1093/nar/gkac838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/11/2022] [Accepted: 09/19/2022] [Indexed: 01/29/2023] Open
Abstract
Ribosome profiling (Ribo-seq) is a powerful method for the transcriptome-wide assessment of protein synthesis rates and the study of translational control mechanisms. Yet, Ribo-seq also has limitations. These include difficulties with the analysis of translation-modulating molecules such as antibiotics, which are often toxic or challenging to deliver into living cells. Here, we have developed in vitro Ribo-seq (INRI-seq), a cell-free method to analyze the translational landscape of a fully customizable synthetic transcriptome. Using Escherichia coli as an example, we show how INRI-seq can be used to analyze the translation initiation sites of a transcriptome of interest. We also study the global impact of direct translation inhibition by antisense peptide nucleic acid (PNA) to analyze PNA off-target effects. Overall, INRI-seq presents a scalable, sensitive method to study translation initiation in a transcriptome-wide manner without the potentially confounding effects of extracting ribosomes from living cells.
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Affiliation(s)
- Jens Hör
- Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
| | - Jakob Jung
- Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
| | - Svetlana Ðurica-Mitić
- Institute for Molecular Infection Biology, University of Würzburg, D-97080 Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research (HZI), D-97080 Würzburg, Germany,Faculty of Medicine, University of Würzburg, D-97080 Würzburg, Germany
| | - Jörg Vogel
- To whom correspondence should be addressed. Tel: +49 931 3182576;
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21
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Komarova ES, Dontsova OA, Pyshnyi DV, Kabilov MR, Sergiev PV. Flow-Seq Method: Features and Application in Bacterial Translation Studies. Acta Naturae 2022; 14:20-37. [PMID: 36694903 PMCID: PMC9844084 DOI: 10.32607/actanaturae.11820] [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: 10/04/2022] [Accepted: 11/11/2022] [Indexed: 01/22/2023] Open
Abstract
The Flow-seq method is based on using reporter construct libraries, where a certain element regulating the gene expression of fluorescent reporter proteins is represented in many thousands of variants. Reporter construct libraries are introduced into cells, sorted according to their fluorescence level, and then subjected to next-generation sequencing. Therefore, it turns out to be possible to identify patterns that determine the expression efficiency, based on tens and hundreds of thousands of reporter constructs in one experiment. This method has become common in evaluating the efficiency of protein synthesis simultaneously by multiple mRNA variants. However, its potential is not confined to this area. In the presented review, a comparative analysis of the Flow-seq method and other alternative approaches used for translation efficiency evaluation of mRNA was carried out; the features of its application and the results obtained by Flow-seq were also considered.
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Affiliation(s)
- E. S. Komarova
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119234 Russia
| | - O. A. Dontsova
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119234 Russia
- Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234 Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117437 Russia
| | - D. V. Pyshnyi
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090 Russia
| | - M. R. Kabilov
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, 630090 Russia
| | - P. V. Sergiev
- Institute of Functional Genomics, Lomonosov Moscow State University, Moscow, 119234 Russia
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119234 Russia
- Skolkovo Institute of Science and Technology, Moscow, 121205 Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119234 Russia
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22
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Duan Y, Zhang X, Zhai W, Zhang J, Zhang X, Xu G, Li H, Deng Z, Shi J, Xu Z. Deciphering the Rules of Ribosome Binding Site Differentiation in Context Dependence. ACS Synth Biol 2022; 11:2726-2740. [PMID: 35877551 DOI: 10.1021/acssynbio.2c00139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ribosome binding site (RBS) is a crucial element regulating translation. However, the activity of RBS is poorly predictable, because it is strongly affected by the local possible secondary structure, that is, context dependence. By the Flowseq technique, over 20 000 RBS variants were sorted and sequenced, and the translation of multiple genes under the same RBS was quantitatively characterized to evaluate the context dependence of each RBS variant in E. coli. Two regions, (-7 to -2) and (-17 to -12), of RBS were predicted with a higher possibility to pair with each other to slow down the translation initiation. Associations between phenotypes and the intrinsic factors suspected to affect translation efficiency and context dependence of the RBS, including nucleotide bias at each position, free energy, and conservation, were disentangled. The results showed that translation efficiency was influenced more significantly by conservation of the SD region (-16 to -8), while an AC-rich spacer region (-7 to -1) was associated with low context dependence. We confirmed these characteristics using a series of synthesized RBSs. The average correlation between multiple reporters was significantly higher for RBSs with an AC-rich spacer (0.714) compared with a GU-rich spacer (0.286). Overall, we proposed general design criteria to improve programmability and minimize context dependence of RBS. The characteristics unraveled here can be adapted to other bacteria for fine-tuning target-gene expression.
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Affiliation(s)
- Yanting Duan
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Xiaojuan Zhang
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Weiji Zhai
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Jinpeng Zhang
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Xiaomei Zhang
- School of Life Science and Health Engineering, Jiangnan University, Wuxi 214122, China.,Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Guoqiang Xu
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
| | - Hui Li
- School of Artificial Intelligence and Computer Science, Jiangnan University, Wuxi 214122, China
| | - Zhaohong Deng
- School of Artificial Intelligence and Computer Science, Jiangnan University, Wuxi 214122, China
| | - Jinsong Shi
- School of Life Science and Health Engineering, Jiangnan University, Wuxi 214122, China.,Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Zhenghong Xu
- Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.,National Engineering Research Center for Cereal Fermentation and Food Biomanufacturing, Jiangnan University, Wuxi 214122, China
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23
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Bushhouse DZ, Choi EK, Hertz LM, Lucks JB. How does RNA fold dynamically? J Mol Biol 2022; 434:167665. [PMID: 35659535 DOI: 10.1016/j.jmb.2022.167665] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 10/18/2022]
Abstract
Recent advances in interrogating RNA folding dynamics have shown the classical model of RNA folding to be incomplete. Here, we pose three prominent questions for the field that are at the forefront of our understanding of the importance of RNA folding dynamics for RNA function. The first centers on the most appropriate biophysical framework to describe changes to the RNA folding energy landscape that a growing RNA chain encounters during transcriptional elongation. The second focuses on the potential ubiquity of strand displacement - a process by which RNA can rapidly change conformations - and how this process may be generally present in broad classes of seemingly different RNAs. The third raises questions about the potential importance and roles of cellular protein factors in RNA conformational switching. Answers to these questions will greatly improve our fundamental knowledge of RNA folding and function, drive biotechnological advances that utilize engineered RNAs, and potentially point to new areas of biology yet to be discovered.
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Affiliation(s)
- David Z Bushhouse
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, Illinois 60208, USA; Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA
| | - Edric K Choi
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, Illinois 60208, USA; Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA
| | - Laura M Hertz
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, Illinois 60208, USA; Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA
| | - Julius B Lucks
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, Illinois 60208, USA; Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, USA; Center for Water Research, Northwestern University, Evanston, Illinois 60208, USA; Center for Engineering Sustainability and Resilience, Northwestern University, Evanston, Illinois 60208, USA.
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24
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Ribosome-binding Sequences (RBS) Engineering of Key Genes in Escherichia coli for High Production of Fatty Alcohols. BIOTECHNOL BIOPROC E 2022. [DOI: 10.1007/s12257-021-0354-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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25
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Terai G, Asai K. QRNAstruct: a method for extracting secondary structural features of RNA via regression with biological activity. Nucleic Acids Res 2022; 50:e73. [PMID: 35390152 PMCID: PMC9303433 DOI: 10.1093/nar/gkac220] [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: 09/13/2021] [Revised: 02/15/2022] [Accepted: 03/24/2022] [Indexed: 12/04/2022] Open
Abstract
Recent technological advances have enabled the generation of large amounts of data consisting of RNA sequences and their functional activity. Here, we propose a method for extracting secondary structure features that affect the functional activity of RNA from sequence–activity data. Given pairs of RNA sequences and their corresponding bioactivity values, our method calculates position-specific structural features of the input RNA sequences, considering every possible secondary structure of each RNA. A Ridge regression model is trained using the structural features as feature vectors and the bioactivity values as response variables. Optimized model parameters indicate how secondary structure features affect bioactivity. We used our method to extract intramolecular structural features of bacterial translation initiation sites and self-cleaving ribozymes, and the intermolecular features between rRNAs and Shine–Dalgarno sequences and between U1 RNAs and splicing sites. We not only identified known structural features but also revealed more detailed insights into structure–activity relationships than previously reported. Importantly, the datasets we analyzed here were obtained from different experimental systems and differed in size, sequence length and similarity, and number of RNA molecules involved, demonstrating that our method is applicable to various types of data consisting of RNA sequences and bioactivity values.
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Affiliation(s)
- Goro Terai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561, Japan
| | - Kiyoshi Asai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba 277-8561, Japan
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Hector RE, Mertens JA, Nichols NN. Increased expression of the fluorescent reporter protein ymNeonGreen in Saccharomyces cerevisiae by reducing RNA secondary structure near the start codon. BIOTECHNOLOGY REPORTS 2022; 33:e00697. [PMID: 35036336 PMCID: PMC8749125 DOI: 10.1016/j.btre.2021.e00697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 11/06/2022]
Abstract
Stable secondary RNA structure 3′ of the start codon inhibits ymNeonGreen expression. Removing secondary RNA structure increased expression in S. cerevisiae and E. coli. Expression was increased 2-fold in S. cerevisiae. Expression was increased 3.8-fold in E. coli. Increased expression in S. cerevisiae was promoter independent.
Expression of a new fluorescent reporter protein called mNeonGreen, that is not based on the jellyfish green fluorescent protein (GFP) sequence, shows increased brightness and folding speed compared to enhanced GFP. However, in vivo brightness of mNeonGreen and its yeast-optimized variant ymNeonGreen in S. cerevisiae is lower than expected, limiting the use of this high quantum yield, fast-folding reporter in budding yeast. This study shows that secondary RNA structure near the start codon in the ymNeonGreen ORF inhibits expression in S. cerevisiae. Removing secondary structure, without altering the ymNeonGreen protein sequence, led to a 2 and 4-fold increase in fluorescence when expressed in S. cerevisiae and E. coli, respectively. In S. cerevisiae, increased fluorescence was seen with strong and weak promoters and led to higher transcript levels suggesting greater transcript stability and improved expression in the absence of stable secondary RNA structure near the start codon.
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27
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Sharma A, Alajangi HK, Pisignano G, Sood V, Singh G, Barnwal RP. RNA thermometers and other regulatory elements: Diversity and importance in bacterial pathogenesis. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1711. [PMID: 35037405 DOI: 10.1002/wrna.1711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 11/09/2021] [Accepted: 12/16/2021] [Indexed: 01/11/2023]
Abstract
Survival of microorganisms depends to a large extent on environmental conditions and the occupied host. By adopting specific strategies, microorganisms can thrive in the surrounding environment and, at the same time, preserve their viability. Evading the host defenses requires several mechanisms compatible with the host survival which include the production of RNA thermometers to regulate the expression of genes responsible for heat or cold shock as well as of those involved in virulence. Microorganisms have developed a variety of molecules in response to the environmental changes in temperature and even more specifically to the host they invade. Among all, RNA-based regulatory mechanisms are the most common ones, highlighting the importance of such molecules in gene expression control and novel drug development by suitable structure-based alterations. This article is categorized under: RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA in Disease and Development > RNA in Disease RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Akanksha Sharma
- Department of Biophysics, Panjab University, Chandigarh, India.,University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
| | - Hema Kumari Alajangi
- Department of Biophysics, Panjab University, Chandigarh, India.,University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
| | | | - Vikas Sood
- Department of Biochemistry, Jamia Hamdard, New Delhi, India
| | - Gurpal Singh
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
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Chen H, Yu J, Hang L, Li S, Lu W, Xu Z. Evidence of the Involvement of Spinal EZH2 in the Development of Bone Cancer Pain in Rats. J Pain Res 2021; 14:3593-3600. [PMID: 34849017 PMCID: PMC8627314 DOI: 10.2147/jpr.s331114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 11/11/2021] [Indexed: 11/26/2022] Open
Abstract
Introduction Bone cancer pain (BCP) seriously affects the quality of life of patients with advanced cancer, but effective treatment methods are lacking. This study mainly investigates the role of EZH2 in a well-established BCP model induced by Walker 256 breast cancer cells in rats. Methods Female Sprague–Dawley rats of the same age weighing approximately 160 g were selected for the experiment. The BCP model was established by injecting inactivated Walker 256 breast cancer cells into the tibia. von Frey filaments were used to measure the paw withdrawal threshold, and bone destruction in the rat was observed using x-ray. The spinal EZH2 and H3K27Tm levels were measured using Western blotting and RT–qPCR analysis. Intrathecal injection of an EZH2 inhibitor was performed to examine the role of EZH2 in trigeminal BCP. Results Experimental results showed that injecting Walker 256 breast cancer cells into the tibia induced bone cancer pain. Spinal EZH2 and H3K27Tm levels were significantly increased over time in BCP rats. An intrathecal injection of 3-deazaneplanocin A (DZNep), a selective EZH2 inhibitor, downregulated the expression of EZH2 and attenuate the BCP-induced mechanical allodynia state. Conclusion Intrathecal injection of DZNep relieve bone cancer pain in rats. EZH2 expressed in spinal cord tissue may be involved in the process of bone cancer pain in rats.
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Affiliation(s)
- Haoming Chen
- Department of Anesthesiology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu, 215300, People's Republic of China
| | - Jianmang Yu
- Department of Anesthesiology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu, 215300, People's Republic of China
| | - Lihua Hang
- Department of Anesthesiology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu, 215300, People's Republic of China
| | - Shuai Li
- Department of Anesthesiology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu, 215300, People's Republic of China
| | - Weikang Lu
- Department of Anesthesiology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu, 215300, People's Republic of China
| | - Zhenkai Xu
- Department of Anesthesiology, Kunshan First People's Hospital Affiliated to Jiangsu University, Kunshan, Jiangsu, 215300, People's Republic of China
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29
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Cai Z, Wang Z, Yue C, Sun A, Shen Y. Efficient expression and purification of soluble Harpin Ea protein by translation initiation region codon optimization. Protein Expr Purif 2021; 188:105970. [PMID: 34500070 DOI: 10.1016/j.pep.2021.105970] [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: 06/04/2021] [Revised: 08/31/2021] [Accepted: 09/05/2021] [Indexed: 11/19/2022]
Abstract
HarpinEa protein can stimulate plants to produce defense responses to resist the attack of pathogens, improve plant immune resistance, and promote plant growth. This has extremely high application value in agriculture. To efficiently express soluble HarpinEa protein, in this study, we expressed HarpinEa protein with a 6× His-tag in Escherichia coli BL21 (DE3). Because of the low level of expression of HarpinEa protein in E. coli, three rounds of synonymous codon optimization were performed on the +53 bp of the translation initiation region (TIR) of HarpinEa. Soluble HarpinEa protein after optimization accounted for 50.3% of the total soluble cellular protein expressed. After purification using a Ni Bestarose Fast Flow column, the purity of HarpinEa protein exceeded 95%, and the yield reached 227.5 mg/L of culture medium. The purified HarpinEa protein was sensitive to proteases and exhibited thermal stability. It triggered visible hypersensitive responses after being injected into tobacco leaves for 48 h. Plants treated with HarpinEa showed obvious growth-promoting and resistance-improving performance. Thus, the use of TIR synonymous codon optimization successfully achieved the economical, efficient, and soluble production of HarpinEa protein.
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Affiliation(s)
- Zengying Cai
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Zhong Wang
- Shandong Shennong Ecological Technology Research Institute Co., Ltd., Shanghai Branch, Shanghai, 201114, China.
| | - Cheng Yue
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Aiyou Sun
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
| | - Yaling Shen
- State Key Laboratory of Bioreactor Engineering, Newworld Institute of Biotechnology, East China University of Science and Technology, Shanghai, 200237, China.
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30
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Nicolet BP, Zandhuis ND, Lattanzio VM, Wolkers MC. Sequence determinants as key regulators in gene expression of T cells. Immunol Rev 2021; 304:10-29. [PMID: 34486113 PMCID: PMC9292449 DOI: 10.1111/imr.13021] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 12/12/2022]
Abstract
T cell homeostasis, T cell differentiation, and T cell effector function rely on the constant fine-tuning of gene expression. To alter the T cell state, substantial remodeling of the proteome is required. This remodeling depends on the intricate interplay of regulatory mechanisms, including post-transcriptional gene regulation. In this review, we discuss how the sequence of a transcript influences these post-transcriptional events. In particular, we review how sequence determinants such as sequence conservation, GC content, and chemical modifications define the levels of the mRNA and the protein in a T cell. We describe the effect of different forms of alternative splicing on mRNA expression and protein production, and their effect on subcellular localization. In addition, we discuss the role of sequences and structures as binding hubs for miRNAs and RNA-binding proteins in T cells. The review thus highlights how the intimate interplay of post-transcriptional mechanisms dictate cellular fate decisions in T cells.
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Affiliation(s)
- Benoit P. Nicolet
- Department of HematopoiesisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteUtrechtThe Netherlands
| | - Nordin D. Zandhuis
- Department of HematopoiesisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteUtrechtThe Netherlands
| | - V. Maria Lattanzio
- Department of HematopoiesisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteUtrechtThe Netherlands
| | - Monika C. Wolkers
- Department of HematopoiesisSanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamThe Netherlands
- Oncode InstituteUtrechtThe Netherlands
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31
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Perlmutter JI, Meyers JE, Bordenstein SR. A single synonymous nucleotide change impacts the male-killing phenotype of prophage WO gene wmk. eLife 2021; 10:67686. [PMID: 34677126 PMCID: PMC8555981 DOI: 10.7554/elife.67686] [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: 02/19/2021] [Accepted: 10/20/2021] [Indexed: 11/13/2022] Open
Abstract
Wolbachia are the most widespread bacterial endosymbionts in animals. Within arthropods, these maternally transmitted bacteria can selfishly hijack host reproductive processes to increase the relative fitness of their transmitting females. One such form of reproductive parasitism called male killing, or the selective killing of infected males, is recapitulated to degrees by transgenic expression of the prophage WO-mediated killing (wmk) gene. Here, we characterize the genotype-phenotype landscape of wmk-induced male killing in D. melanogaster using transgenic expression. While phylogenetically distant wmk homologs induce no sex-ratio bias, closely-related homologs exhibit complex phenotypes spanning no death, male death, or death of all hosts. We demonstrate that alternative start codons, synonymous codons, and notably a single synonymous nucleotide in wmk can ablate killing. These findings reveal previously unrecognized features of transgenic wmk-induced killing and establish new hypotheses for the impacts of post-transcriptional processes in male killing variation. We conclude that synonymous sequence changes are not necessarily silent in nested endosymbiotic interactions with life-or-death consequences.
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Affiliation(s)
- Jessamyn I Perlmutter
- Department of Biological Sciences, Vanderbilt University, Nashville, United States.,Department of Molecular Biosciences, University of Kansas, Lawrence, United States.,Vanderbilt Microbiome Innovation Center, Vanderbilt University, Nashville, United States
| | - Jane E Meyers
- Department of Biological Sciences, Vanderbilt University, Nashville, United States.,Vanderbilt Microbiome Innovation Center, Vanderbilt University, Nashville, United States
| | - Seth R Bordenstein
- Department of Biological Sciences, Vanderbilt University, Nashville, United States.,Vanderbilt Microbiome Innovation Center, Vanderbilt University, Nashville, United States.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, United States.,Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University, Nashville, United States
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32
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Sun M, Gao AX, Li A, Liu X, Wang R, Yang Y, Li Y, Liu C, Bai Z. Bicistronic design as recombinant expression enhancer: characteristics, applications, and structural optimization. Appl Microbiol Biotechnol 2021; 105:7709-7720. [PMID: 34596722 DOI: 10.1007/s00253-021-11611-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/16/2021] [Accepted: 09/18/2021] [Indexed: 11/30/2022]
Abstract
The bicistronic design (BCD) is characterized by a short fore-cistron sequence and a second Shine-Dalgarno (SD2) sequence upstream of the target gene. The outstanding performance of this expression cassette in promoting recombinant protein production has attracted attention. Recently, the application of the BCD has been further extended to gene expression control, protein translation monitoring, and membrane protein production. In this review, we summarize the characteristics, molecular mechanisms, applications, and structural optimization of the BCD expression cassette. We also specifically discuss the challenges that the BCD system still faces. This is the first review of the BCD expression strategy, and it is believed that an in-depth understanding of the BCD will help researchers to better utilize and develop it. KEY POINTS: • Summary of the characteristics and molecular mechanisms of the BCD system. • Review of the actual applications of the BCD expression cassette. • Summary of the structural optimization of the BCD system.
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Affiliation(s)
- Manman Sun
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Alex Xiong Gao
- Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China
| | - An Li
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Xiuxia Liu
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. .,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China.
| | - Rongbing Wang
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Yankun Yang
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Ye Li
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Chunli Liu
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China.,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China
| | - Zhonghu Bai
- National Engineering Laboratory of Cereal Fermentation Technology, Jiangnan University, Wuxi, 214112, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China. .,Jiangsu Provincial Research Center for Bioactive Product Processing Technology, Jiangnan University, Wuxi, 214122, China.
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Bhandari BK, Lim CS, Remus DM, Chen A, van Dolleweerd C, Gardner PP. Analysis of 11,430 recombinant protein production experiments reveals that protein yield is tunable by synonymous codon changes of translation initiation sites. PLoS Comput Biol 2021; 17:e1009461. [PMID: 34610008 PMCID: PMC8519471 DOI: 10.1371/journal.pcbi.1009461] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 10/15/2021] [Accepted: 09/19/2021] [Indexed: 12/16/2022] Open
Abstract
Recombinant protein production is a key process in generating proteins of interest in the pharmaceutical industry and biomedical research. However, about 50% of recombinant proteins fail to be expressed in a variety of host cells. Here we show that the accessibility of translation initiation sites modelled using the mRNA base-unpairing across the Boltzmann's ensemble significantly outperforms alternative features. This approach accurately predicts the successes or failures of expression experiments, which utilised Escherichia coli cells to express 11,430 recombinant proteins from over 189 diverse species. On this basis, we develop TIsigner that uses simulated annealing to modify up to the first nine codons of mRNAs with synonymous substitutions. We show that accessibility captures the key propensity beyond the target region (initiation sites in this case), as a modest number of synonymous changes is sufficient to tune the recombinant protein expression levels. We build a stochastic simulation model and show that higher accessibility leads to higher protein production and slower cell growth, supporting the idea of protein cost, where cell growth is constrained by protein circuits during overexpression.
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Affiliation(s)
- Bikash K. Bhandari
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Chun Shen Lim
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Daniela M. Remus
- Callaghan Innovation Protein Science and Engineering, University of Canterbury, Christchurch, New Zealand
| | - Augustine Chen
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Craig van Dolleweerd
- Biomolecular Interaction Center, University of Canterbury, Christchurch, New Zealand
| | - Paul P. Gardner
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Biomolecular Interaction Center, University of Canterbury, Christchurch, New Zealand
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34
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Enhancing the Cell-Free Expression of Native Membrane Proteins by In Silico Optimization of the Coding Sequence-An Experimental Study of the Human Voltage-Dependent Anion Channel. MEMBRANES 2021; 11:membranes11100741. [PMID: 34677509 PMCID: PMC8540592 DOI: 10.3390/membranes11100741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022]
Abstract
Membrane proteins are involved in many aspects of cellular biology; for example, they regulate how cells interact with their environment, so such proteins are important drug targets. The rapid advancement in the field of immune effector cell therapy has been expanding the horizons of synthetic membrane receptors in the areas of cell-based immunotherapy and cellular medicine. However, the investigation of membrane proteins, which are key constituents of cells, is hampered by the difficulty and complexity of their in vitro synthesis, which is of unpredictable yield. Cell-free synthesis is herein employed to unravel the impact of the expression construct on gene transcription and translation, without the complex regulatory mechanisms of cellular systems. Through the systematic design of plasmids in the immediacy of the start of the target gene, it was possible to identify translation initiation and the conformation of mRNA as the main factors governing the cell-free expression efficiency of the human voltage-dependent anion channel (VDAC), which is a relevant membrane protein in drug-based therapy. A simple translation initiation model was developed to quantitatively assess the expression potential for the designed constructs. A scoring function that quantifies the feasibility of the formation of the translation initiation complex through the ribosome–mRNA hybridization energy and the accessibility of the mRNA segment binding to the ribosome is proposed. The scoring function enables one to optimize plasmid sequences and semi-quantitatively predict protein expression efficiencies. This scoring function is publicly available as webservice XenoExpressO at University of Vienna, Austria.
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35
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Bao C, Ermolenko DN. Ribosome as a Translocase and Helicase. BIOCHEMISTRY (MOSCOW) 2021; 86:992-1002. [PMID: 34488575 PMCID: PMC8294220 DOI: 10.1134/s0006297921080095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
During protein synthesis, ribosome moves along mRNA to decode one codon after the other. Ribosome translocation is induced by a universally conserved protein, elongation factor G (EF-G) in bacteria and elongation factor 2 (EF-2) in eukaryotes. EF-G-induced translocation results in unwinding of the intramolecular secondary structures of mRNA by three base pairs at a time that renders the translating ribosome a processive helicase. Professor Alexander Sergeevich Spirin has made numerous seminal contributions to understanding the molecular mechanism of translocation. Here, we review Spirin's insights into the ribosomal translocation and recent advances in the field that stemmed from Spirin's pioneering work. We also discuss key remaining challenges in studies of translocase and helicase activities of the ribosome.
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Affiliation(s)
- Chen Bao
- Department of Biochemistry & Biophysics, School of Medicine and Dentistry and Center for RNA Biology, University of Rochester, Rochester, NY, USA.
| | - Dmitri N Ermolenko
- Department of Biochemistry & Biophysics, School of Medicine and Dentistry and Center for RNA Biology, University of Rochester, Rochester, NY, USA.
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36
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Bharmal MHM, Gega A, Schrader JM. A combination of mRNA features influence the efficiency of leaderless mRNA translation initiation. NAR Genom Bioinform 2021; 3:lqab081. [PMID: 34568822 PMCID: PMC8459731 DOI: 10.1093/nargab/lqab081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/03/2021] [Accepted: 08/27/2021] [Indexed: 12/30/2022] Open
Abstract
Bacterial translation is thought to initiate by base pairing of the 16S rRNA and the Shine-Dalgarno sequence in the mRNA's 5' untranslated region (UTR). However, transcriptomics has revealed that leaderless mRNAs, which completely lack any 5' UTR, are broadly distributed across bacteria and can initiate translation in the absence of the Shine-Dalgarno sequence. To investigate the mechanism of leaderless mRNA translation initiation, synthetic in vivo translation reporters were designed that systematically tested the effects of start codon accessibility, leader length, and start codon identity on leaderless mRNA translation initiation. Using these data, a simple computational model was built based on the combinatorial relationship of these mRNA features that can accurately classify leaderless mRNAs and predict the translation initiation efficiency of leaderless mRNAs. Thus, start codon accessibility, leader length, and start codon identity combine to define leaderless mRNA translation initiation in bacteria.
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Affiliation(s)
| | - Alisa Gega
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
| | - Jared M Schrader
- Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA
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37
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Bhandari BK, Lim CS, Gardner PP. TISIGNER.com: web services for improving recombinant protein production. Nucleic Acids Res 2021; 49:W654-W661. [PMID: 33744969 PMCID: PMC8265118 DOI: 10.1093/nar/gkab175] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/17/2021] [Accepted: 03/03/2021] [Indexed: 12/25/2022] Open
Abstract
Experiments that are planned using accurate prediction algorithms will mitigate failures in recombinant protein production. We have developed TISIGNER (https://tisigner.com) with the aim of addressing technical challenges to recombinant protein production. We offer three web services, TIsigner (Translation Initiation coding region designer), SoDoPE (Soluble Domain for Protein Expression) and Razor, which are specialised in synonymous optimisation of recombinant protein expression, solubility and signal peptide analysis, respectively. Importantly, TIsigner, SoDoPE and Razor are linked, which allows users to switch between the tools when optimising genes of interest.
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Affiliation(s)
- Bikash K Bhandari
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Chun Shen Lim
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
| | - Paul P Gardner
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin 9054, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, Christchurch 8140, New Zealand
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38
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Gawroński P, Enroth C, Kindgren P, Marquardt S, Karpiński S, Leister D, Jensen PE, Vinther J, Scharff LB. Light-Dependent Translation Change of Arabidopsis psbA Correlates with RNA Structure Alterations at the Translation Initiation Region. Cells 2021; 10:322. [PMID: 33557293 PMCID: PMC7914831 DOI: 10.3390/cells10020322] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/26/2021] [Accepted: 01/29/2021] [Indexed: 01/21/2023] Open
Abstract
mRNA secondary structure influences translation. Proteins that modulate the mRNA secondary structure around the translation initiation region may regulate translation in plastids. To test this hypothesis, we exposed Arabidopsis thaliana to high light, which induces translation of psbA mRNA encoding the D1 subunit of photosystem II. We assayed translation by ribosome profiling and applied two complementary methods to analyze in vivo RNA secondary structure: DMS-MaPseq and SHAPE-seq. We detected increased accessibility of the translation initiation region of psbA after high light treatment, likely contributing to the observed increase in translation by facilitating translation initiation. Furthermore, we identified the footprint of a putative regulatory protein in the 5' UTR of psbA at a position where occlusion of the nucleotide sequence would cause the structure of the translation initiation region to open up, thereby facilitating ribosome access. Moreover, we show that other plastid genes with weak Shine-Dalgarno sequences (SD) are likely to exhibit psbA-like regulation, while those with strong SDs do not. This supports the idea that changes in mRNA secondary structure might represent a general mechanism for translational regulation of psbA and other plastid genes.
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Affiliation(s)
- Piotr Gawroński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland; (P.G.); (S.K.)
| | - Christel Enroth
- Department of Biology, Section for Computational and RNA Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 København N, Denmark; (C.E.); (J.V.)
| | - Peter Kindgren
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark; (P.K.); (S.M.)
| | - Sebastian Marquardt
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark; (P.K.); (S.M.)
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Biotechnology, Institute of Biology, Warsaw University of Life Sciences, Nowoursynowska 159, 02-776 Warsaw, Poland; (P.G.); (S.K.)
| | - Dario Leister
- Plant Molecular Biology, Department Biology I, Ludwig-Maximilians-University Munich, Großhadernerstr. 2-4, 82152 Planegg-Martinsried, Germany;
| | - Poul Erik Jensen
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark;
| | - Jeppe Vinther
- Department of Biology, Section for Computational and RNA Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 København N, Denmark; (C.E.); (J.V.)
| | - Lars B. Scharff
- Copenhagen Plant Science Centre, Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark; (P.K.); (S.M.)
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Duan Y, Zhai W, Liu W, Zhang X, Shi JS, Zhang X, Xu Z. Fine-Tuning Multi-Gene Clusters via Well-Characterized Gene Expression Regulatory Elements: Case Study of the Arginine Synthesis Pathway in C. glutamicum. ACS Synth Biol 2021; 10:38-48. [PMID: 33382575 DOI: 10.1021/acssynbio.0c00405] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Promoters and ribosome binding sites (RBSs) are routinely applied in gene expression regulation, but their orthogonality and combinatorial effects have not yet been systematically studied in Corynebacterium glutamicum. Here, 17 core promoters and 29 RBSs in C. glutamicum were characterized, which exhibited 470-fold and 430-fold in transcriptional and translational activity, respectively. By comparing the expression of two reporter genes regulated by multiple RBSs, the RBS efficacy showed significant dependence on the gene context, besides the RBSs' strength, reflecting the poor orthogonality of RBSs. Bicistron-modified RBS (referred as bc-RBS) was adapted to C. glutamicum, which improved RBS reliability. By coupling a series of promoters with RBSs/bc-RBSs, a much broader regulation range that spanned 4 orders of magnitude was observed compared with that of a sole element, and the contribution to gene expression of RBS was more than that of promoter. Finally, promoters and RBSs were applied as built-in elements to fine-tune the gene cluster in the arginine synthesis pathway in C. glutamicum. Compared with the original strain, more arginine (1.61-fold) or citrulline (2.35-fold) was accumulated in a 7 L bioreactor by strains with the gene expression regulation system rationally engineered. We demonstrated that, via combination of well-characterized gene elements, and overall consideration for both transcription and translation, the biosynthesis pathway can be effectively balanced, and the yield of a target metabolite can be further improved.
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Affiliation(s)
- Yanting Duan
- National Engineering Laboratory for Cereal Fermentation Technology, Key Laboratory of Industrial Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
- Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Weiji Zhai
- National Engineering Laboratory for Cereal Fermentation Technology, Key Laboratory of Industrial Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
- Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Weijia Liu
- Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Xiaomei Zhang
- School of Pharmaceutical Science, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
- Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Jin-Song Shi
- School of Pharmaceutical Science, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
- Jiangsu Engineering Research Center for Bioactive Products Processing Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Xiaojuan Zhang
- National Engineering Laboratory for Cereal Fermentation Technology, Key Laboratory of Industrial Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
- Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
| | - Zhenghong Xu
- National Engineering Laboratory for Cereal Fermentation Technology, Key Laboratory of Industrial Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
- Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, Wuxi 214122, China
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40
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Meydan S, Klepacki D, Mankin AS, Vázquez-Laslop N. Identification of Translation Start Sites in Bacterial Genomes. Methods Mol Biol 2021; 2252:27-55. [PMID: 33765270 DOI: 10.1007/978-1-0716-1150-0_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The knowledge of translation start sites is crucial for annotation of genes in bacterial genomes. However, systematic mapping of start codons in bacterial genes has mainly relied on predictions based on protein conservation and mRNA sequence features which, although useful, are not always accurate. We recently found that the pleuromutilin antibiotic retapamulin (RET) is a specific inhibitor of translation initiation that traps ribosomes specifically at start codons, and we used it in combination with ribosome profiling to map start codons in the Escherichia coli genome. This genome-wide strategy, that was named Ribo-RET, not only verifies the position of start codons in already annotated genes but also enables identification of previously unannotated open reading frames and reveals the presence of internal start sites within genes. Here, we provide a detailed Ribo-RET protocol for E. coli. Ribo-RET can be adapted for mapping the start codons of the protein-coding sequences in a variety of bacterial species.
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Affiliation(s)
- Sezen Meydan
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Dorota Klepacki
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Alexander S Mankin
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA.
| | - Nora Vázquez-Laslop
- Center for Biomolecular Sciences, University of Illinois at Chicago, Chicago, IL, USA.
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41
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Wen JD, Kuo ST, Chou HHD. The diversity of Shine-Dalgarno sequences sheds light on the evolution of translation initiation. RNA Biol 2020; 18:1489-1500. [PMID: 33349119 DOI: 10.1080/15476286.2020.1861406] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Shine-Dalgarno (SD) sequences, the core element of prokaryotic ribosome-binding sites, facilitate mRNA translation by base-pair interaction with the anti-SD (aSD) sequence of 16S rRNA. In contrast to this paradigm, an inspection of thousands of prokaryotic species unravels tremendous SD sequence diversity both within and between genomes, whereas aSD sequences remain largely static. The pattern has led many to suggest unidentified mechanisms for translation initiation. Here we review known translation-initiation pathways in prokaryotes. Moreover, we seek to understand the cause and consequence of SD diversity through surveying recent advances in biochemistry, genomics, and high-throughput genetics. These findings collectively show: (1) SD:aSD base pairing is beneficial but nonessential to translation initiation. (2) The 5' untranslated region of mRNA evolves dynamically and correlates with organismal phylogeny and ecological niches. (3) Ribosomes have evolved distinct usage of translation-initiation pathways in different species. We propose a model portraying the SD diversity shaped by optimization of gene expression, adaptation to environments and growth demands, and the species-specific prerequisite of ribosomes to initiate translation. The model highlights the coevolution of ribosomes and mRNA features, leading to functional customization of the translation apparatus in each organism.
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Affiliation(s)
- Jin-Der Wen
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan.,Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan
| | - Syue-Ting Kuo
- Department of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hsin-Hung David Chou
- Genome and Systems Biology Degree Program, Academia Sinica and National Taiwan University, Taipei, Taiwan.,Department of Life Science, National Taiwan University, Taipei, Taiwan
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Osire T, Yang T, Xu M, Zhang X, Long M, Ngon NKA, Rao Z. Integrated gene engineering synergistically improved substrate-product transport, cofactor generation and gene translation for cadaverine biosynthesis in E. coli. Int J Biol Macromol 2020; 169:8-17. [PMID: 33301846 DOI: 10.1016/j.ijbiomac.2020.12.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 12/03/2020] [Indexed: 12/13/2022]
Abstract
Several approaches for efficient production of cadaverine, a bio-based diamine with broad industrial applications have been explored. Here, Serratia marcescens lysine decarboxylase (SmcadA) was expressed in E. coli; mild surfactants added in biotransformation reactions; the E. coli native lysine/cadaverine antiporter cadB, E. coli pyridoxal kinases pdxK and pdxY overexpressed and synthetic RBS libraries screened. Addition of mild surfactants and overexpression of antiporter cadB increased cadaverine biosynthesis of SmcadA. Moreover, expression of pdxY gene yielded 19.82 g/L in a reaction mixture containing added cofactor precursor pyridoxal (PL), without adding exogenous PLP. The screened synthetic RBS1, applied to fully exploit pdxY gene expression, ultimately resulted in PLP self-sufficiency, producing 27.02 g/L cadaverine using strain T7R1_PL. To boost SmcadA catalytic activity, the designed mutants Arg595Lys and Ser512Ala had significantly improved cumulative cadaverine production of 219.54 and 201.79 g/L respectively compared to the wild-type WT (181.62 g/L), after 20 h reaction. Finally, molecular dynamics simulations for WT and variants indicated that increased flexibility at the binding sites of the protein enhanced residue-ligand interactions, contributing to high cadaverine synthesis. This work demonstrates potential of harnessing different pull factors through integrated gene engineering of efficient biocatalysts and gaining insight into the mechanisms involved through MD simulations.
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Affiliation(s)
- Tolbert Osire
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China
| | - Taowei Yang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China
| | - Meijuan Xu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China
| | - Xian Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China
| | - Mengfei Long
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China
| | - Noelle Kewang A Ngon
- National Engineering Laboratory for Cereal Fermentation Technology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China
| | - Zhiming Rao
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 LiHu Boulevard, Wuxi 214122, Jiangsu, China.
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43
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Romilly C, Lippegaus A, Wagner E. An RNA pseudoknot is essential for standby-mediated translation of the tisB toxin mRNA in Escherichia coli. Nucleic Acids Res 2020; 48:12336-12347. [PMID: 33231643 PMCID: PMC7708055 DOI: 10.1093/nar/gkaa1139] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/03/2020] [Accepted: 11/07/2020] [Indexed: 01/20/2023] Open
Abstract
In response to DNA damage, Escherichia coli cells activate the expression of the toxin gene tisB of the toxin-antitoxin system tisB-istR1. Of three isoforms, only the processed, highly structured +42 tisB mRNA is active. Translation requires a standby site, composed of two essential elements: a single-stranded region located 100 nucleotides upstream of the sequestered RBS, and a structure near the 5'-end of the active mRNA. Here, we propose that this 5'-structure is an RNA pseudoknot which is required for 30S and protein S1-alone binding to the mRNA. Point mutations that prevent formation of this pseudoknot inhibit formation of translation initiation complexes, impair S1 and 30S binding to the mRNA, and render the tisB mRNA non-toxic in vivo. A set of mutations created in either the left or right arm of stem 2 of the pseudoknot entailed loss of toxicity upon overexpression of the corresponding mRNA variants. Combining the matching right-left arm mutations entirely restored toxicity levels to that of the wild-type, active mRNA. Finally, since many pseudoknots have high affinity for S1, we predicted similar pseudoknots in non-homologous type I toxin-antitoxin systems that exhibit features similar to that of tisB-IstR1, suggesting a shared requirement for standby acting at great distances.
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MESH Headings
- Bacterial Toxins/genetics
- Bacterial Toxins/metabolism
- Base Pairing
- Base Sequence
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Escherichia coli Proteins/genetics
- Escherichia coli Proteins/metabolism
- Gene Expression Regulation, Bacterial
- Nucleic Acid Conformation
- Point Mutation
- Protein Binding
- Protein Biosynthesis
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Bacterial/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Ribosomal Proteins/genetics
- Ribosomal Proteins/metabolism
- Ribosome Subunits, Small, Bacterial/genetics
- Ribosome Subunits, Small, Bacterial/metabolism
- Toxin-Antitoxin Systems/genetics
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Affiliation(s)
- Cédric Romilly
- Department of Cell and Molecular Biology, Uppsala University, Uppsala S-75124, Sweden
| | - Anne Lippegaus
- Department of Cell and Molecular Biology, Uppsala University, Uppsala S-75124, Sweden
| | - E Gerhart H Wagner
- Department of Cell and Molecular Biology, Uppsala University, Uppsala S-75124, Sweden
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44
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Jazurek-Ciesiolka M, Ciesiolka A, Komur AA, Urbanek-Trzeciak MO, Krzyzosiak WJ, Fiszer A. RAN Translation of the Expanded CAG Repeats in the SCA3 Disease Context. J Mol Biol 2020; 432:166699. [PMID: 33157084 DOI: 10.1016/j.jmb.2020.10.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 01/08/2023]
Abstract
Spinocerebellar ataxia type 3 (SCA3) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the ATXN3 gene encoding the ataxin-3 protein. Despite extensive research the exact pathogenic mechanisms of SCA3 are still not understood in depth. In the present study, to gain insight into the toxicity induced by the expanded CAG repeats in SCA3, we comprehensively investigated repeat-associated non-ATG (RAN) translation in various cellular models expressing translated or non-canonically translated ATXN3 sequences with an increasing number of CAG repeats. We demonstrate that two SCA3 RAN proteins, polyglutamine (polyQ) and polyalanine (polyA), are found only in the case of CAG repeats of pathogenic length. Despite having distinct cellular localization, RAN polyQ and RAN polyA proteins are very often coexpressed in the same cell, impairing nuclear integrity and inducing apoptosis. We provide for the first time mechanistic insights into SCA3 RAN translation indicating that ATXN3 sequences surrounding the repeat region have an impact on SCA3 RAN translation initiation and efficiency. We revealed that RAN translation of polyQ proteins starts at non-cognate codons upstream of the CAG repeats, whereas RAN polyA proteins are likely translated within repeats. Furthermore, integrated stress response activation enhances SCA3 RAN translation. Our findings suggest that the ATXN3 sequence context plays an important role in triggering SCA3 RAN translation and that SCA3 RAN proteins may cause cellular toxicity.
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Affiliation(s)
- Magdalena Jazurek-Ciesiolka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
| | - Adam Ciesiolka
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Alicja A Komur
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Martyna O Urbanek-Trzeciak
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Wlodzimierz J Krzyzosiak
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Agnieszka Fiszer
- Department of Medical Biotechnology, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland.
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45
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Sun H, Yang J, Song H. Engineering mycobacteria artificial promoters and ribosomal binding sites for enhanced sterol production. Biochem Eng J 2020. [DOI: 10.1016/j.bej.2020.107739] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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46
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Kawaguchi D, Kodama A, Abe N, Takebuchi K, Hashiya F, Tomoike F, Nakamoto K, Kimura Y, Shimizu Y, Abe H. Phosphorothioate Modification of mRNA Accelerates the Rate of Translation Initiation to Provide More Efficient Protein Synthesis. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202007111] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Daisuke Kawaguchi
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Ayumi Kodama
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Naoko Abe
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
- Research Center for Materials Science Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Kei Takebuchi
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Fumitaka Hashiya
- Research Center for Materials Science Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Fumiaki Tomoike
- Research Center for Materials Science Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Kosuke Nakamoto
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Yasuaki Kimura
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
| | - Yoshihiro Shimizu
- Biodynamics Research Center (BDR) RIKEN 6-2-3, Furuedai Suita Osaka 565-0874 Japan
| | - Hiroshi Abe
- Chemistry Department Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
- Research Center for Materials Science Nagoya University Furo-cho, Chikusa-ku Nagoya Aichi 464-8602 Japan
- CREST (Japan) Science and Technology Agency 7, Gobancho, Chiyoda-ku Tokyo 102-0076 Japan
- Institute for Glyco-core Research Tokai National Higher Education and Research System Furo-cho, Chikusa-ku Nagoya Aichi 464-8601 Japan
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47
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Terai G, Asai K. Improving the prediction accuracy of protein abundance in Escherichia coli using mRNA accessibility. Nucleic Acids Res 2020; 48:e81. [PMID: 32504488 PMCID: PMC7641306 DOI: 10.1093/nar/gkaa481] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/25/2020] [Accepted: 05/26/2020] [Indexed: 02/06/2023] Open
Abstract
RNA secondary structure around translation initiation sites strongly affects the abundance of expressed proteins in Escherichia coli. However, detailed secondary structural features governing protein abundance remain elusive. Recent advances in high-throughput DNA synthesis and experimental systems enable us to obtain large amounts of data. Here, we evaluated six types of structural features using two large-scale datasets. We found that accessibility, which is the probability that a given region around the start codon has no base-paired nucleotides, showed the highest correlation with protein abundance in both datasets. Accessibility showed a significantly higher correlation (Spearman's ρ = 0.709) than the widely used minimum free energy (0.554) in one of the datasets. Interestingly, accessibility showed the highest correlation only when it was calculated by a log-linear model, indicating that the RNA structural model and how to utilize it are important. Furthermore, by combining the accessibility and activity of the Shine-Dalgarno sequence, we devised a method for predicting protein abundance more accurately than existing methods. We inferred that the log-linear model has a broader probabilistic distribution than the widely used Turner energy model, which contributed to more accurate quantification of ribosome accessibility to translation initiation sites.
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Affiliation(s)
- Goro Terai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Japan
| | - Kiyoshi Asai
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, University of Tokyo, Japan
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48
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Ye B, Luo Y, Zhong B, Zhu J, Huang J, Gu J, Jiang J, Yan X, He J, He Q. High-level stable expression of gene for preparation of chlorothalonil hydrolytic dehalogenase and its application in elimination of chlorothalonil inhibition on bioconversion of lignocellulosic biomass. J Biosci Bioeng 2020; 130:630-636. [PMID: 32958392 DOI: 10.1016/j.jbiosc.2020.08.003] [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: 04/30/2020] [Revised: 07/27/2020] [Accepted: 08/01/2020] [Indexed: 11/29/2022]
Abstract
To achieve the high-level stable expression of chlorothalonil hydrolytic dehalogenase (Chd), the gene chd was first integrated into the chromosome of Bacillus subtilis WB800. High generation stability was achieved by almost no gene lost after six generations but Chd activity decreased. aprE promoter alteration, translation initiation region modification and multi-copy chromosome integration were studied and these modifications could increase Chd activity by 270%, 2304% and 25%. Chlorothalonil residual exhibited inhibition on bioconversion of lignocellulosic biomass. The addition of Chd crude enzyme (60 μL per g wheat straw) could increase glucose production by 36.10% and 39.65% in synergistic hydrolysis and separate hydrolysis by laccase and cellulase with 120 mg/L residual chlorothalonil. Filter paper activity and carboxymethyl cellulase activity were enhanced by 12.84% and 23.95%, and biomass of Trichoderma reesei was increased by 76.67% under 50 μg chlorothalonil/g dry straw in solid-state fermentation. Thus, the high-level stable expressed Chd effectively eliminated chlorothalonil inhibition on enzymatic hydrolysis and solid-state fermentation. It showed promising potential for bioremediation of chlorothalonil pollution and improving conversion efficiency of lignocellulose.
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Affiliation(s)
- Bin Ye
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Yanfei Luo
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Bangchao Zhong
- Chongqing Key Laboratory of Green Synthesis and Applications, College of Chemistry, Chongqing Normal University, Chongqing, 401331, PR China
| | - Jianchun Zhu
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China; Life Science Laboratory Center, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Junwei Huang
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Jiayu Gu
- Nantong Lianhai Weijing Biology Co., Ltd, Haimen, 226133, Jiangsu, PR China
| | - Jiandong Jiang
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Xin Yan
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Jian He
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China
| | - Qin He
- Department of Microbiology, Key Lab of Microbiological Engineering of Agricultural Environment, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, PR China; Department of Bioengineering, Imperial College London, SW7 2AZ, London, UK.
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49
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Secondary structure of the mRNA encoding listeriolysin O is essential to establish the replicative niche of L. monocytogenes. Proc Natl Acad Sci U S A 2020; 117:23774-23781. [PMID: 32878997 DOI: 10.1073/pnas.2004129117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Intracellular pathogens are responsible for an enormous amount of worldwide morbidity and mortality, and each has evolved specialized strategies to establish and maintain their replicative niche. Listeria monocytogenes is a facultative intracellular pathogen that secretes a pore-forming cytolysin called listeriolysin O (LLO), which disrupts the phagosomal membrane and, thereby, allows the bacteria access to their replicative niche in the cytosol. Nonsynonymous and synonymous mutations in a PEST-like domain near the LLO N terminus cause enhanced LLO translation during intracellular growth, leading to host cell death and loss of virulence. Here, we explore the mechanism of translational control and show that there is extensive codon restriction within the PEST-encoding region of the LLO messenger RNA (mRNA) (hly). This region has considerable complementarity with the 5' UTR and is predicted to form an extensive secondary structure that overlaps the ribosome binding site. Analysis of both 5' UTR and synonymous mutations in the PEST-like domain that are predicted to disrupt the secondary structure resulted in up to a 10,000-fold drop in virulence during mouse infection, while compensatory double mutants restored virulence to WT levels. We showed by dynamic protein radiolabeling that LLO synthesis was growth phase-dependent. These data provide a mechanism to explain how the bacteria regulate translation of LLO to promote translation during starvation in a phagosome while repressing it during growth in the cytosol. These studies also provide a molecular explanation for codon bias at the 5' end of this essential determinant of pathogenesis.
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Heidari-Japelaghi R, Valizadeh M, Haddad R, Dorani-Uliaie E, Jalali-Javaran M. Production of bioactive human IFN-γ protein by agroinfiltration in tobacco. Protein Expr Purif 2020; 173:105616. [PMID: 32179088 DOI: 10.1016/j.pep.2020.105616] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/25/2020] [Accepted: 02/25/2020] [Indexed: 11/25/2022]
Abstract
In animals, interferon-γ (IFN-γ) is known as a cytokine involved in antiviral and anticancer activities with a higher biochemical activity in contrast to other IFNs. To produce recombinant human IFN-γ (hIFN-γ) protein in tobacco, factors influencing gene delivery were first evaluated for higher efficiency of transient expression by fluorometric measurement of GUS activity. Higher levels of transient expression were observed in leaves of Nicotiana tabacum cv. Samsun infiltrated with GV3101 strain (optical density equal to 1.0 at 600 nm) under treatment of 200 μM AS at 4 days post agroinfiltration (dpa). The Samsun cv. proved to be amenable with 1.4- and 1.5-fold higher levels of transient expression than Xanthi and N. benthamiana, respectively. In addition, the GV3101 remained the best strain for use in transient assays without any necrotic response in tobacco. The levels of transient hIFN-γ expression were also estimated in the Samsun cv. infiltrated with different Agrobacterium tumefaciens strains carrying various expression constructs. Higher levels of accumulation were obtained with targeting the hIFN-γ protein to endoplasmic reticulum (ER) or apoplastic space than those expressed into cytoplasm. Moreover, antiviral bioassay revealed that recombinant hIFN-γ protein produced in tobacco is biologically active and protects the Vero cells from infection generated by vesicular stomatitis virus (VSV).
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Affiliation(s)
- Reza Heidari-Japelaghi
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran.
| | - Mostafa Valizadeh
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Raheem Haddad
- Department of Biotechnology, Faculty of Agriculture and Natural Resources, Imam Khomeini International University, Qazvin, Iran
| | - Ebrahim Dorani-Uliaie
- Department of Plant Breeding and Biotechnology, Faculty of Agriculture, University of Tabriz, Tabriz, Iran
| | - Mokhtar Jalali-Javaran
- Department of Plant Breeding, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran
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