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Zhang Y, Wang L, Wang F, Chu X, Jiang JH. G-Quadruplex mRNAs Silencing with Inducible Ribonuclease Targeting Chimera for Precision Tumor Therapy. J Am Chem Soc 2024; 146:15815-15824. [PMID: 38832857 DOI: 10.1021/jacs.4c02091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Ribonuclease targeting chimera (RIBOTAC) represents an emerging strategy for targeted therapy. However, RIBOTAC that is selectively activated by bio-orthogonal or cell-specific triggers has not been explored. We developed a strategy of inducible RIBOTAC (iRIBOTAC) that enables on-demand degradation of G-quadruplex (G4) RNAs for precision cancer therapy. iRIBOTAC is designed by coupling an RNA G4 binder with a caged ribonuclease recruiter, which can be decaged by a bio-orthogonal reaction, tumor-specific enzyme, or metabolite. A bivalent G4 binder is engineered by conjugating a near-infrared (NIR) fluorescence G4 ligand to a noncompetitive G4 ligand, conferring fluorescence activation on binding G4s with synergistically enhanced affinity. iRIBOTAC is demonstrated to greatly knockdown G4 RNAs upon activation under bio-orthogonal or cell-specific stimulus, with dysregulation of gene expressions involving cell killing, channel regulator activity, and metabolism as revealed by RNA sequencing. This strategy also shows a crucial effect on cell fate with remarkable biochemical hallmarks of apoptosis. Mice model studies demonstrate that iRIBOTAC allows selective imaging and growth suppression of tumors with bio-orthogonal and tumor-specific controls, highlighting G4 RNA targeting and inducible silencing as a valuable RIBOTAC paradigm for cancer therapy.
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Affiliation(s)
- Yuan Zhang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Lingyan Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Fenglin Wang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Xia Chu
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
| | - Jian-Hui Jiang
- State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha, Hunan 410082, China
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2
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Li H, Li J, Li J, Li H, Wang X, Jiang J, Lei L, Sun H, Tang M, Dong B, He W, Si S, Hong B, Li Y, Song D, Peng Z, Che Y, Jiang JD. Carrimycin inhibits coronavirus replication by decreasing the efficiency of programmed -1 ribosomal frameshifting through directly binding to the RNA pseudoknot of viral frameshift-stimulatory element. Acta Pharm Sin B 2024; 14:2567-2580. [PMID: 38828157 PMCID: PMC11143517 DOI: 10.1016/j.apsb.2024.02.023] [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: 10/18/2023] [Revised: 01/08/2024] [Accepted: 02/04/2024] [Indexed: 06/05/2024] Open
Abstract
The pandemic of SARS-CoV-2 worldwide with successive emerging variants urgently calls for small-molecule oral drugs with broad-spectrum antiviral activity. Here, we show that carrimycin, a new macrolide antibiotic in the clinic and an antiviral candidate for SARS-CoV-2 in phase III trials, decreases the efficiency of programmed -1 ribosomal frameshifting of coronaviruses and thus impedes viral replication in a broad-spectrum fashion. Carrimycin binds directly to the coronaviral frameshift-stimulatory element (FSE) RNA pseudoknot, interrupting the viral protein translation switch from ORF1a to ORF1b and thereby reducing the level of the core components of the viral replication and transcription complexes. Combined carrimycin with known viral replicase inhibitors yielded a synergistic inhibitory effect on coronaviruses. Because the FSE mechanism is essential in all coronaviruses, carrimycin could be a new broad-spectrum antiviral drug for human coronaviruses by directly targeting the conserved coronaviral FSE RNA. This finding may open a new direction in antiviral drug discovery for coronavirus variants.
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Affiliation(s)
- Hongying Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jianrui Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jiayu Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Hu Li
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Xuekai Wang
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jing Jiang
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Lei Lei
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Han Sun
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Mei Tang
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Biao Dong
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Weiqing He
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Shuyi Si
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Bin Hong
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Yinghong Li
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Danqing Song
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Zonggen Peng
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Yongsheng Che
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
| | - Jian-Dong Jiang
- CAMS Key Laboratory of Antiviral Drug Research, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
- Key Laboratory of Biotechnology of Antibiotics, the National Health and Family Planning Commission (NHFPC), Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
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3
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Brown A, Brill J, Amini R, Nurmi C, Li Y. Development of Better Aptamers: Structured Library Approaches, Selection Methods, and Chemical Modifications. Angew Chem Int Ed Engl 2024; 63:e202318665. [PMID: 38253971 DOI: 10.1002/anie.202318665] [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: 12/05/2023] [Revised: 01/22/2024] [Accepted: 01/22/2024] [Indexed: 01/24/2024]
Abstract
Systematic evolution of ligands by exponential enrichment (SELEX) has been used to discover thousands of aptamers since its development in 1990. Aptamers are short single-stranded oligonucleotides capable of binding to targets with high specificity and selectivity through structural recognition. While aptamers offer advantages over other molecular recognition elements such as their ease of production, smaller size, extended shelf-life, and lower immunogenicity, they have yet to show significant success in real-world applications. By analyzing the importance of structured library designs, reviewing different SELEX methodologies, and the effects of chemical modifications, we provide a comprehensive overview on the production of aptamers for applications in drug delivery systems, therapeutics, diagnostics, and molecular imaging.
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Affiliation(s)
- Alex Brown
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4 K1, Canada
| | - Jake Brill
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4 K1, Canada
| | - Ryan Amini
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4 K1, Canada
| | - Connor Nurmi
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4 K1, Canada
| | - Yingfu Li
- Department of Biochemistry and Biomedical Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4 K1, Canada
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4
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Kramat J, Kraus L, Gunawan VJ, Smyej E, Froehlich P, Weber TE, Spiehl D, Koeppl H, Blaeser A, Suess B. Sensing Levofloxacin with an RNA Aptamer as a Bioreceptor. BIOSENSORS 2024; 14:56. [PMID: 38275309 PMCID: PMC10813692 DOI: 10.3390/bios14010056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/11/2024] [Accepted: 01/12/2024] [Indexed: 01/27/2024]
Abstract
To combat the growing threat of antibiotic resistance, environmental testing for antibiotic contamination is gaining an increasing role. This study aims to develop an easy-to-use assay for the detection of the fluoroquinolone antibiotic levofloxacin. Levofloxacin is used in human and veterinary medicine and has been detected in wastewater and river water. An RNA aptamer against levofloxacin was selected using RNA Capture-SELEX. The 73 nt long aptamer folds into three stems with a central three-way junction. It binds levofloxacin with a Kd of 6 µM and discriminates the closely related compound ciprofloxacin. Furthermore, the selection process was analyzed using a next-generation sequencing approach to better understand the sequence evolution throughout the selection. The aptamer was used as a bioreceptor for the development of a lateral flow assay. The biosensor exploited the innate characteristic of RNA Capture-SELEX to select aptamers that displace a complementary DNA oligonucleotide upon ligand binding. The lateral flow assay achieved a limit of visual detection of 100 µM. While the sensitivity of this assay constrains its immediate use in environmental testing, the present study can serve as a template for the selection of RNA aptamer-based biosensors.
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Affiliation(s)
- Janice Kramat
- Synthetic RNA Biology, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Leon Kraus
- Synthetic RNA Biology, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Vincent J. Gunawan
- Synthetic RNA Biology, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Elias Smyej
- Synthetic RNA Biology, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Philipp Froehlich
- Self-Organizing Systems, Department of Electrical Engineering and Information Technology, Technical University of Darmstadt, 64283 Darmstadt, Germany
| | - Tim E. Weber
- Institute for BioMedical Printing Technologies, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Dieter Spiehl
- Institute for BioMedical Printing Technologies, Technical University of Darmstadt, 64289 Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Heinz Koeppl
- Self-Organizing Systems, Department of Electrical Engineering and Information Technology, Technical University of Darmstadt, 64283 Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Andreas Blaeser
- Institute for BioMedical Printing Technologies, Technical University of Darmstadt, 64289 Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Beatrix Suess
- Synthetic RNA Biology, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, Technical University of Darmstadt, 64289 Darmstadt, Germany
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5
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Vockenhuber MP, Hoetzel J, Maurer LM, Fröhlich P, Weiler S, Muller YA, Koeppl H, Suess B. A Novel RNA Aptamer as Synthetic Inducer of DasR Controlled Transcription. ACS Synth Biol 2024; 13:319-327. [PMID: 38127784 DOI: 10.1021/acssynbio.3c00553] [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: 12/23/2023]
Abstract
Progress in the synthetic biology field is driven by the development of new tools for synthetic circuit engineering. Traditionally, the focus has relied on protein-based designs. In recent years, the use of RNA-based tools has tremendously increased, due to their versatile functionality and applicability. A promising class of molecules is RNA aptamers, small, single-stranded RNA molecules that bind to a target molecule with high affinity and specificity. When targeting bacterial repressors, RNA aptamers allow one to add a new layer to an established protein-based regulation. In the present study, we selected an RNA aptamer binding the bacterial repressor DasR, preventing its binding to its operator sequence and activating DasR-controlled transcription in vivo. This was made possible only by the combination of an in vitro selection and subsequent in vivo screening. Next-generation sequencing of the selection process proved the importance of the in vivo screening for the discovery of aptamers functioning in the cell. Mutational and biochemical studies led to the identification of the minimal necessary binding motif. Taken together, the resulting combination of bacterial repressor and RNA aptamer enlarges the synthetic biology toolbox by adding a new level of regulation.
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Affiliation(s)
- Michael-Paul Vockenhuber
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Center for Synthetic Microbiology (SYNMIKRO), Philipps-Universität Marburg, Karl-von-Frisch-Strasse 14, 35043 Marburg, Germany
| | - Janis Hoetzel
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Lisa-Marie Maurer
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Philipp Fröhlich
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Sigrid Weiler
- Lehrstuhl für Biotechnik, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Henkestr. 91, 91052 Erlangen, Germany
| | - Yves A Muller
- Lehrstuhl für Biotechnik, Department of Biology, Friedrich-Alexander University Erlangen-Nürnberg, Henkestr. 91, 91052 Erlangen, Germany
| | - Heinz Koeppl
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
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6
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Wu Y, Zhu L, Zhang Y, Xu W. Multidimensional Applications and Challenges of Riboswitches in Biosensing and Biotherapy. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2024; 20:e2304852. [PMID: 37658499 DOI: 10.1002/smll.202304852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/15/2023] [Indexed: 09/03/2023]
Abstract
Riboswitches have received significant attention over the last two decades for their multiple functionalities and great potential for applications in various fields. This article highlights and reviews the recent advances in biosensing and biotherapy. These fields involve a wide range of applications, such as food safety detection, environmental monitoring, metabolic engineering, live cell imaging, wearable biosensors, antibacterial drug targets, and gene therapy. The discovery, origin, and optimization of riboswitches are summarized to help readers better understand their multidimensional applications. Finally, this review discusses the multidimensional challenges and development of riboswitches in order to further expand their potential for novel applications.
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Affiliation(s)
- Yifan Wu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Longjiao Zhu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Yangzi Zhang
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
| | - Wentao Xu
- Key Laboratory of Precision Nutrition and Food Quality, Beijing Laboratory for Food Quality and Safety, Department of Nutrition and Health, China Agricultural University, Beijing, 100191, China
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7
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Kraus L, Duchardt-Ferner E, Bräuchle E, Fürbacher S, Kelvin D, Marx H, Boussebayle A, Maurer LM, Bofill-Bosch C, Wöhnert J, Suess B. Development of a novel tobramycin dependent riboswitch. Nucleic Acids Res 2023; 51:11375-11385. [PMID: 37791877 PMCID: PMC10639043 DOI: 10.1093/nar/gkad767] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/30/2023] [Accepted: 09/12/2023] [Indexed: 10/05/2023] Open
Abstract
We herein report the selection and characterization of a new riboswitch dependent on the aminoglycoside tobramycin. Its dynamic range rivals even the tetracycline dependent riboswitch to be the current best performing, synthetic riboswitch that controls translation initiation. The riboswitch was selected with RNA Capture-SELEX, a method that not only selects for binding but also for structural changes in aptamers on binding. This study demonstrates how this method can fundamentally reduce the labour required for the de novo identification of synthetic riboswitches. The initially selected riboswitch candidate harbours two distinct tobramycin binding sites with KDs of 1.1 nM and 2.4 μM, respectively, and can distinguish between tobramycin and the closely related compounds kanamycin A and B. Using detailed genetic and biochemical analyses and 1H NMR spectroscopy, the proposed secondary structure of the riboswitch was verified and the tobramycin binding sites were characterized. The two binding sites were found to be essentially non-overlapping, allowing for a separate investigation of their contribution to the activity of the riboswitch. We thereby found that only the high-affinity binding site was responsible for regulatory activity, which allowed us to engineer a riboswitch from only this site with a minimal sequence size of 33 nt and outstanding performance.
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Affiliation(s)
- Leon Kraus
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, TU Darmstadt, 64287 Darmstadt, Germany
| | - Elke Duchardt-Ferner
- Institut für Molekulare Biowissenschaften und Zentrum für Biomolekulare Magnetische Resonanz (BMRZ), Goethe-Universität Frankfurt, Max-von-Laue Straße 9, 60438 Frankfurt, Germany
| | - Eric Bräuchle
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Simon Fürbacher
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Daniel Kelvin
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, TU Darmstadt, 64287 Darmstadt, Germany
| | - Hans Marx
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Institute of Microbiology and Microbial Biotechnology BOKU University of Natural Resources and Life Sciences, Muthgasse 18, A-1190 Vienna, Austria
| | - Adrien Boussebayle
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Interdisciplinary Nanoscience Center (iNANO), Gustav Wieds Vej 14, Aarhus University, DK-8000 Aarhus, Denmark
| | - Lisa-Marie Maurer
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, TU Darmstadt, 64287 Darmstadt, Germany
- Institut für Molekulare Biowissenschaften und Zentrum für Biomolekulare Magnetische Resonanz (BMRZ), Goethe-Universität Frankfurt, Max-von-Laue Straße 9, 60438 Frankfurt, Germany
| | - Cristina Bofill-Bosch
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Jens Wöhnert
- Institut für Molekulare Biowissenschaften und Zentrum für Biomolekulare Magnetische Resonanz (BMRZ), Goethe-Universität Frankfurt, Max-von-Laue Straße 9, 60438 Frankfurt, Germany
| | - Beatrix Suess
- Fachbereich Biologie, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
- Centre for Synthetic Biology, TU Darmstadt, 64287 Darmstadt, Germany
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8
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Kaiser C, Vogel M, Appel B, Weigand J, Müller S, Suess B, Wachtveitl J. Magnesium Ion-Driven Folding and Conformational Switching Kinetics of Tetracycline Binding Aptamer: Implications for in vivo Riboswitch Engineering. J Mol Biol 2023; 435:168253. [PMID: 37640152 DOI: 10.1016/j.jmb.2023.168253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/22/2023] [Accepted: 08/22/2023] [Indexed: 08/31/2023]
Abstract
Engineering in vitro selected RNA aptamers into in vivo functional riboswitches represents a long-standing challenge in molecular biology. The highly specific aptamer domain of the riboswitch undergoes a conformational adjustment in response to ligand sensing, which in turn exerts the regulatory function. Besides essential factors like structural complexity and ligand binding kinetics, the active role of magnesium ions in stabilizing RNA tertiary structures and assisting in ligand binding can be a vital criterion. We present spectroscopic studies on the magnesium ion-driven folding of the Tetracycline binding aptamer. Using fluorescent labels, the aptamer pre-folding and subsequent ligand binding is monitored by magnesium titration experiments and time-resolved stopped-flow measurements. A minimum concentration of 0.5 mM magnesium is required to fold into a magnesium ion-stabilized binding-competent state with a preformed binding pocket. Tetracycline binding causes a pronounced conformational change that results in the establishment of the triple helix core motif, and that further propagates towards the closing stem. By a dynamic acquisition of magnesium ions, a kink motif is formed at the intersection of the triple helix and closing stem regions. This ultimately entails a stabilization of the closing stem which is discussed as a key element in the regulatory function of the Tetracycline aptamer.
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Affiliation(s)
- Christoph Kaiser
- Institute for Physical and Theoretical Chemistry, Goethe University, Frankfurt/Main, Max-von-Laue Str. 9, D-60438, Germany.
| | - Marc Vogel
- Department of Biology, Technical University Darmstadt, Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany
| | - Bettina Appel
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, D-17489 Greifswald, Germany
| | - Julia Weigand
- Department of Biology, Technical University Darmstadt, Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany; Institute of Pharmaceutical Chemistry, Philipps-University Marburg, Marburg, Marbacher Weg 6, D-35037, Germany. https://twitter.com/WachtveitlLab
| | - Sabine Müller
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, D-17489 Greifswald, Germany
| | - Beatrix Suess
- Department of Biology, Technical University Darmstadt, Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany; Centre for Synthetic Biology, Technical University Darmstadt, Darmstadt, Germany.
| | - Josef Wachtveitl
- Institute for Physical and Theoretical Chemistry, Goethe University, Frankfurt/Main, Max-von-Laue Str. 9, D-60438, Germany.
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9
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Kim M, Jo H, Jung GY, Oh SS. Molecular Complementarity of Proteomimetic Materials for Target-Specific Recognition and Recognition-Mediated Complex Functions. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2208309. [PMID: 36525617 DOI: 10.1002/adma.202208309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/29/2022] [Indexed: 06/02/2023]
Abstract
As biomolecules essential for sustaining life, proteins are generated from long chains of 20 different α-amino acids that are folded into unique 3D structures. In particular, many proteins have molecular recognition functions owing to their binding pockets, which have complementary shapes, charges, and polarities for specific targets, making these biopolymers unique and highly valuable for biomedical and biocatalytic applications. Based on the understanding of protein structures and microenvironments, molecular complementarity can be exhibited by synthesizable and modifiable materials. This has prompted researchers to explore the proteomimetic potentials of a diverse range of materials, including biologically available peptides and oligonucleotides, synthetic supramolecules, inorganic molecules, and related coordination networks. To fully resemble a protein, proteomimetic materials perform the molecular recognition to mediate complex molecular functions, such as allosteric regulation, signal transduction, enzymatic reactions, and stimuli-responsive motions; this can also expand the landscape of their potential bio-applications. This review focuses on the recognitive aspects of proteomimetic designs derived for individual materials and their conformations. Recent progress provides insights to help guide the development of advanced protein mimicry with material heterogeneity, design modularity, and tailored functionality. The perspectives and challenges of current proteomimetic designs and tools are also discussed in relation to future applications.
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Affiliation(s)
- Minsun Kim
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Hyesung Jo
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Gyoo Yeol Jung
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
| | - Seung Soo Oh
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, South Korea
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10
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Ortega AD. Real-Time Assessment of Intracellular Metabolites in Single Cells through RNA-Based Sensors. Biomolecules 2023; 13:biom13050765. [PMID: 37238635 DOI: 10.3390/biom13050765] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Quantification of the concentration of particular cellular metabolites reports on the actual utilization of metabolic pathways in physiological and pathological conditions. Metabolite concentration also constitutes the readout for screening cell factories in metabolic engineering. However, there are no direct approaches that allow for real-time assessment of the levels of intracellular metabolites in single cells. In recent years, the modular architecture of natural bacterial RNA riboswitches has inspired the design of genetically encoded synthetic RNA devices that convert the intracellular concentration of a metabolite into a quantitative fluorescent signal. These so-called RNA-based sensors are composed of a metabolite-binding RNA aptamer as the sensor domain, connected through an actuator segment to a signal-generating reporter domain. However, at present, the variety of available RNA-based sensors for intracellular metabolites is still very limited. Here, we go through natural mechanisms for metabolite sensing and regulation in cells across all kingdoms, focusing on those mediated by riboswitches. We review the design principles underlying currently developed RNA-based sensors and discuss the challenges that hindered the development of novel sensors and recent strategies to address them. We finish by introducing the current and potential applicability of synthetic RNA-based sensors for intracellular metabolites.
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Affiliation(s)
- Alvaro Darío Ortega
- Department of Cell Biology, Faculty of Biological Sciences, Complutense University of Madrid, 28040 Madrid, Spain
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11
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Chang Y, Sun W, Murchie AIH, Chen D. Genome-wide identification of Kanamycin B binding RNA in Escherichia coli. BMC Genomics 2023; 24:120. [PMID: 36927548 PMCID: PMC10018874 DOI: 10.1186/s12864-023-09234-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 03/07/2023] [Indexed: 03/18/2023] Open
Abstract
BACKGROUND The aminoglycosides are established antibiotics that inhibit bacterial protein synthesis by binding to ribosomal RNA. Additional non-antibiotic aminoglycoside cellular functions have also been identified through aminoglycoside interactions with cellular RNAs. The full extent, however, of genome-wide aminoglycoside RNA interactions in Escherichia coli has not been determined. Here, we report genome-wide identification and verification of the aminoglycoside Kanamycin B binding to Escherichia coli RNAs. Immobilized Kanamycin B beads in pull-down assays were used for transcriptome-profiling analysis (RNA-seq). RESULTS Over two hundred Kanamycin B binding RNAs were identified. Functional classification analysis of the RNA sequence related genes revealed a wide range of cellular functions. Small RNA fragments (ncRNA, tRNA and rRNA) or small mRNA was used to verify the binding with Kanamycin B in vitro. Kanamycin B and ibsC mRNA was analysed by chemical probing. CONCLUSIONS The results will provide biochemical evidence and understanding of potential extra-antibiotic cellular functions of aminoglycosides in Escherichia coli.
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Affiliation(s)
- Yaowen Chang
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Wenxia Sun
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China.,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Alastair I H Murchie
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China. .,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
| | - Dongrong Chen
- Fudan University Pudong Medical Center, and Institute of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, 200032, Shanghai, China. .,Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China.
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12
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Hossain MI, Myers M, Herath D, Aldhumani AH, Boesger H, Hines JV. 4-Aminoquinolines modulate RNA structure and function: Pharmacophore implications of a conformationally restricted polyamine. Biochem Biophys Res Commun 2023; 644:55-61. [PMID: 36630735 PMCID: PMC10473465 DOI: 10.1016/j.bbrc.2022.12.080] [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: 12/16/2022] [Accepted: 12/28/2022] [Indexed: 12/30/2022]
Abstract
RNA structure plays an important role in regulating cellular function and there is a significant emerging interest in targeting RNA for drug discovery. Here we report the identification of 4-aminoquinolines as modulators of RNA structure and function. Aminoquinolines have a broad range of pharmacological activities, but their specific mechanism of action is often not fully understood. Using electrophoretic mobility shift assays and enzymatic probing we identified 4-aminoquinolines that bind the stem-loop II motif (s2m) of SARS-CoV-2 RNA site-specifically and induce dimerization. Using fluorescence-based RNA binding and T-box riboswitch functional assays we identified that hydroxychloroquine binds the T-box riboswitch antiterminator RNA element and inhibits riboswitch function. Based on its structure and riboswitch dose-response activity we identified that the antagonist activity of hydroxychloroquine is consistent with it being a conformationally restricted analog of the polyamine spermidine. Given the known role that polyamines play in RNA function, the identification of an RNA binding ligand with the pharmacophore of a conformationally restricted polyamine has significant implications for further elucidation of RNA structure-function relationships and RNA-targeted drug discovery.
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Affiliation(s)
- Md Ismail Hossain
- Department of Chemistry & Biochemistry, Ohio University, Athens, OH, 45701, USA
| | - Mason Myers
- Department of Chemistry & Biochemistry, Ohio University, Athens, OH, 45701, USA; Honors Tutorial College, Ohio University, Athens, OH, 45701, USA
| | - Danushika Herath
- Department of Chemistry & Biochemistry, Ohio University, Athens, OH, 45701, USA; Molecular & Cellular Biology Program, Ohio University, Athens, OH, 45701, USA
| | - Ali H Aldhumani
- Department of Chemistry & Biochemistry, Ohio University, Athens, OH, 45701, USA
| | - Hannah Boesger
- Department of Biological Sciences, Ohio University, Athens, OH, 45701, USA; Honors Tutorial College, Ohio University, Athens, OH, 45701, USA
| | - Jennifer V Hines
- Department of Chemistry & Biochemistry, Ohio University, Athens, OH, 45701, USA; Molecular & Cellular Biology Program, Ohio University, Athens, OH, 45701, USA.
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13
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Dong X, Qi S, Khan IM, Sun Y, Zhang Y, Wang Z. Advances in riboswitch-based biosensor as food samples detection tool. Compr Rev Food Sci Food Saf 2023; 22:451-472. [PMID: 36511082 DOI: 10.1111/1541-4337.13077] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/09/2022] [Accepted: 10/25/2022] [Indexed: 12/14/2022]
Abstract
Food safety has always been a hot issue of social concern, and biosensing has been widely used in the field of food safety detection. Compared with traditional aptamer-based biosensors, aptamer-based riboswitch biosensing represents higher precision and programmability. A riboswitch is an elegant example of controlling gene expression, where the target is coupled to the aptamer domain, resulting in a conformational change in the downstream expression domain and determining the signal output. Riboswitch-based biosensing can be extensively applied to the portable real-time detection of food samples. The numerous key features of riboswitch-based biosensing emphasize their sustainability, renewable, and testing, which promises to transform engineering applications in the field of food safety. This review covers recent developments in riboswitch-based biosensors. The brief history, definition, and modular design (regulatory mode, reporter, and expression platform) of riboswitch-based biosensors are explained for better insight into the design and construction. We summarize recent advances in various riboswitch-based biosensors involving theophylline, malachite green, tetracycline, neomycin, fluoride, thrombin, naringenin, ciprofloxacin, and paromomycin, aiming to provide general guidance for the design of riboswitch-based biosensors. Finally, the challenges and prospects are also summarized as a way forward stratagem and signs of progress.
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Affiliation(s)
- Xiaoze Dong
- State Key Laboratory of Food Science and Technology, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Shuo Qi
- State Key Laboratory of Food Science and Technology, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Imran Mahmood Khan
- State Key Laboratory of Food Science and Technology, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Yuhan Sun
- State Key Laboratory of Food Science and Technology, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China
| | - Yin Zhang
- Key Laboratory of Meat Processing of Sichuan, Chengdu University, Chengdu, China
| | - Zhouping Wang
- State Key Laboratory of Food Science and Technology, International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China.,School of Food Science and Technology, Jiangnan University, Wuxi, China.,Key Laboratory of Meat Processing of Sichuan, Chengdu University, Chengdu, China.,National Engineering Research Center for Functional Food, Jiangnan University, Wuxi, China.,Collaborative innovation center of food safety and quality control in Jiangsu Province, Food, Jiangnan University, Wuxi, China
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14
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Lam SY, Lau HL, Kwok CK. Capture-SELEX: Selection Strategy, Aptamer Identification, and Biosensing Application. BIOSENSORS 2022; 12:bios12121142. [PMID: 36551109 PMCID: PMC9776347 DOI: 10.3390/bios12121142] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 11/26/2022] [Accepted: 11/29/2022] [Indexed: 06/01/2023]
Abstract
Small-molecule contaminants, such as antibiotics, pesticides, and plasticizers, have emerged as one of the substances most detrimental to human health and the environment. Therefore, it is crucial to develop low-cost, user-friendly, and portable biosensors capable of rapidly detecting these contaminants. Antibodies have traditionally been used as biorecognition elements. However, aptamers have recently been applied as biorecognition elements in aptamer-based biosensors, also known as aptasensors. The systematic evolution of ligands by exponential enrichment (SELEX) is an in vitro technique used to generate aptamers that bind their targets with high affinity and specificity. Over the past decade, a modified SELEX method known as Capture-SELEX has been widely used to generate DNA or RNA aptamers that bind small molecules. In this review, we summarize the recent strategies used for Capture-SELEX, describe the methods commonly used for detecting and characterizing small-molecule-aptamer interactions, and discuss the development of aptamer-based biosensors for various applications. We also discuss the challenges of the Capture-SELEX platform and biosensor development and the possibilities for their future application.
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Affiliation(s)
- Sin Yu Lam
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China
| | - Hill Lam Lau
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China
| | - Chun Kit Kwok
- State Key Laboratory of Marine Pollution and Department of Chemistry, City University of Hong Kong, Hong Kong SAR 999077, China
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, China
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15
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Pan Y, Yang H, Wen K, Ke Y, Shen J, Wang Z. Current advances in immunoassays for quinolones in food and environmental samples. Trends Analyt Chem 2022. [DOI: 10.1016/j.trac.2022.116726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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16
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Liu Y, Deng Y, Li S, Wang-Ngai Chow F, Liu M, He N. Monitoring and detection of antibiotic residues in animal derived foods: Solutions using aptamers. Trends Food Sci Technol 2022. [DOI: 10.1016/j.tifs.2022.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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17
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Hoetzel J, Suess B. Structural changes in aptamers are essential for synthetic riboswitch engineering. J Mol Biol 2022; 434:167631. [PMID: 35595164 DOI: 10.1016/j.jmb.2022.167631] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 11/19/2022]
Abstract
Synthetic riboswitches are powerful tools in synthetic biology in which sensing and execution are consolidated in a single RNA molecule. By using SELEX to select aptamers in vitro, synthetic riboswitches can in theory be engineered against any ligand of choice. Surprisingly, very few in vitro selected aptamers have been used for the engineering of synthetic riboswitches. In-depth studies of these aptamers suggest that the key characteristics of such regulatory active RNAs are their structural switching abilities and their binding dynamics. Conventional SELEX approaches seem to be inadequate to select for these characteristics, which may explain the lack of in vitro selected aptamers suited for engineering of synthetic riboswitches. In this review, we explore the functional principles of synthetic riboswitches, identify key characteristics of regulatory active in vitro selected aptamers and integrate these findings in context with available in vitro selection methods. Based on these insights, we propose to use a combination of capture-SELEX and subsequent functional screening for a more successful in vitro selection of aptamers that can be applied for the engineering of synthetic riboswitches.
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Affiliation(s)
- Janis Hoetzel
- Department of Biology, Technical University of Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany. https://www.twitter.com/J_Hoetzel
| | - Beatrix Suess
- Department of Biology, Technical University of Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany; Center for Synthetic Biology, Technical University of Darmstadt, Germany.
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18
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Wang T, Simmel FC. Riboswitch-inspired toehold riboregulators for gene regulation in Escherichia coli. Nucleic Acids Res 2022; 50:4784-4798. [PMID: 35446427 PMCID: PMC9071393 DOI: 10.1093/nar/gkac275] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 04/08/2022] [Indexed: 12/24/2022] Open
Abstract
Regulatory RNA molecules have been widely investigated as components for synthetic gene circuits, complementing the use of protein-based transcription factors. Among the potential advantages of RNA-based gene regulators are their comparatively simple design, sequence-programmability, orthogonality, and their relatively low metabolic burden. In this work, we developed a set of riboswitch-inspired riboregulators in Escherichia coli that combine the concept of toehold-mediated strand displacement (TMSD) with the switching principles of naturally occurring transcriptional and translational riboswitches. Specifically, for translational activation and repression, we sequestered anti-anti-RBS or anti-RBS sequences, respectively, inside the loop of a stable hairpin domain, which is equipped with a single-stranded toehold region at its 5' end and is followed by regulated sequences on its 3' side. A trigger RNA binding to the toehold region can invade the hairpin, inducing a structural rearrangement that results in translational activation or deactivation. We also demonstrate that TMSD can be applied in the context of transcriptional regulation by switching RNA secondary structure involved in Rho-dependent termination. Our designs expand the repertoire of available synthetic riboregulators by a set of RNA switches with no sequence limitation, which should prove useful for the development of robust genetic sensors and circuits.
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Affiliation(s)
- Tianhe Wang
- Physics of Synthetic Biological Systems – E14, Physics Department and ZNN, Technische Universität München, Am Coulombwall 4a, 85748 Garching, Germany
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19
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Tabuchi T, Yokobayashi Y. High-throughput screening of cell-free riboswitches by fluorescence-activated droplet sorting. Nucleic Acids Res 2022; 50:3535-3550. [PMID: 35253887 PMCID: PMC8989549 DOI: 10.1093/nar/gkac152] [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: 01/26/2022] [Revised: 02/15/2022] [Accepted: 02/20/2022] [Indexed: 11/14/2022] Open
Abstract
Cell-free systems that display complex functions without using living cells are emerging as new platforms to test our understanding of biological systems as well as for practical applications such as biosensors and biomanufacturing. Those that use cell-free protein synthesis (CFPS) systems to enable genetically programmed protein synthesis have relied on genetic regulatory components found or engineered in living cells. However, biological constraints such as cell permeability, metabolic stability, and toxicity of signaling molecules prevent development of cell-free devices using living cells even if cell-free systems are not subject to such constraints. Efforts to engineer regulatory components directly in CFPS systems thus far have been based on low-throughput experimental approaches, limiting the availability of basic components to build cell-free systems with diverse functions. Here, we report a high-throughput screening method to engineer cell-free riboswitches that respond to small molecules. Droplet-sorting of riboswitch variants in a CFPS system rapidly identified cell-free riboswitches that respond to compounds that are not amenable to bacterial screening methods. Finally, we used a histamine riboswitch to demonstrate chemical communication between cell-sized droplets.
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Affiliation(s)
- Takeshi Tabuchi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904-0495, Japan
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20
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Fang X, Li W, Gao T, Ain Zahra QU, Luo Z, Pei R. Rapid screening of aptamers for fluorescent targets by integrated digital PCR and flow cytometry. Talanta 2022; 242:123302. [PMID: 35180537 DOI: 10.1016/j.talanta.2022.123302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/08/2022] [Accepted: 02/09/2022] [Indexed: 10/19/2022]
Abstract
In this paper, we report the development of a new strategy termed integrated digital PCR-fluorescence activated sorting based SELEX (IFS-SELEX) that enables rapid screening of aptamers against fluorescent targets. Initially, this strategy employs an integrated digital PCR system to amplify each sequence of a preliminarily enriched library, which is obtained by a traditional SELEX method, on the surface of polystyrene beads. Then, the as-prepared beads are incubated with the fluorescent target and then subjected to fluorescence-activated sorting. Since only those sequences with high binding affinity for the target are collected and sequenced, unnecessary analysis of ineligible sequences is avoided by this method, and the aptamer selection process is thereby greatly streamlined. As a proof-of-concept, we applied this strategy for the screening of aptamers against two fluorescent targets, i.e., ciprofloxacin (CFX) and thioflavin T (ThT), and successfully obtained corresponding sequences with low dissociation constants. The binding affinities of aptamers for ThT were well associated with the sorting regions defined in the fluorescence channel of the flow cytometry process. The experimental results demonstrated that the as-designed IFS-SELEX method can serve as a universal platform for rapid, facile, and efficient aptamer selection against various fluorescent targets.
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Affiliation(s)
- Xiaona Fang
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory for Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Wenjing Li
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory for Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Tian Gao
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory for Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China
| | - Qurat Ul Ain Zahra
- Biomedical Imaging Center, University of Science and Technology of China, Hefei, Anhui, 230026, China; The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, 310022, China
| | - Zhaofeng Luo
- The Key Laboratory of Zhejiang Province for Aptamers and Theranostics, Institute of Basic Medicine and Cancer (IBMC), Chinese Academy of Sciences, Hangzhou, 310022, China.
| | - Renjun Pei
- School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei, 230026, China; CAS Key Laboratory for Nano-Bio Interface, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China.
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21
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Kramat J, Suess B. Efficient Method to Identify Synthetic Riboswitches Using RNA-Based Capture-SELEX Combined with In Vivo Screening. Methods Mol Biol 2022; 2518:157-177. [PMID: 35666445 DOI: 10.1007/978-1-0716-2421-0_10] [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: 06/15/2023]
Abstract
Synthetic riboswitches are a promising tool for conditional gene expression. In vitro selected aptamers used as binding domains for the design of RNA-based switches have to exhibit excellent binding affinity as well as ligand binding-induced structural changes. Selection via Capture-SELEX favors the enrichment of aptamers which exhibit both characteristics. For the Capture-SELEX, an RNA pool is used that gets immobilized onto a capture oligonucleotide by hybridization. Addition of the ligand frees the aptamers by their binding to the ligand, resulting in the release from the capture oligonucleotide through structural changes. These sequences get reverse transcribed, PCR amplified, and used for the following selection rounds. In this publication, we present a detailed protocol for Capture-SELEX, followed by screening in yeast to identify aptamers suitable for the design of synthetic riboswitches.
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Affiliation(s)
- Janice Kramat
- Department of Biology, Technical University Darmstadt, Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technical University Darmstadt, Darmstadt, Germany.
- Centre of Synthetic Biology, Technical University Darmstadt, Darmstadt, Germany.
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22
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Cai X, Wang Q, Fang Y, Yao D, Zhan Y, An B, Yan B, Cai J. Attenuator LRR - a regulatory tool for modulating gene expression in Gram-positive bacteria. Microb Biotechnol 2021; 14:2538-2551. [PMID: 33720523 PMCID: PMC8601186 DOI: 10.1111/1751-7915.13797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 02/24/2021] [Accepted: 02/24/2021] [Indexed: 11/28/2022] Open
Abstract
With the rapid development of synthetic biology in recent years, particular attention has been paid to RNA devices, especially riboswitches, because of their significant and diverse regulatory roles in prokaryotic and eukaryotic cells. Due to the limited performance and context-dependence of riboswitches, only a few of them (such as theophylline, tetracycline and ciprofloxacin riboswitches) have been utilized as regulatory tools in biotechnology. In the present study, we demonstrated that a ribosome-dependent ribo-regulator, LRR, discovered in our previous work, exhibits an attractive regulatory performance. Specifically, it offers a 60-fold change in expression in the presence of retapamulin and a low level of leaky expression of about 1-2% without antibiotics. Moreover, LRR can be combined with different promoters and performs well in Bacillus thuringiensis, B. cereus, B. amyloliquefaciens, and B. subtilis. Additionally, LRR also functions in the Gram-negative bacterium Escherichia coli. Furthermore, we demonstrate its ability to control melanin metabolism in B. thuringiensis BMB171. Our results show that LRR can be applied to regulate gene expression, construct genetic circuits and tune metabolic pathways, and has great potential for many applications in synthetic biology.
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Affiliation(s)
- Xia Cai
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Qian Wang
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Yu Fang
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Die Yao
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Yunda Zhan
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Baoju An
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Bing Yan
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
| | - Jun Cai
- Department of MicrobiologyCollege of Life SciencesNankai UniversityTianjin300071China
- Key Laboratory of Molecular Microbiology and TechnologyMinistry of EducationTianjin300071China
- Tianjin Key Laboratory of Microbial Functional GenomicsTianjin300071China
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23
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Liu Y, Yuan H, Ding D, Dong H, Wang Q, Zhang D. Establishment of a Biosensor-based High-Throughput Screening Platform for Tryptophan Overproduction. ACS Synth Biol 2021; 10:1373-1383. [PMID: 34081459 DOI: 10.1021/acssynbio.0c00647] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
With the flexibility to fold into complex structures, RNA is well-suited to act as a cellular sensor to recognize environmental fluctuations and respond to changes by regulating the corresponding genes. In this study, we established a high-throughput screening platform to screen tryptophan high-producing strains from a large repertoire of candidate strains. This platform consists of a tryptophan-specific aptamer-based biosensor and fluorescence-activated droplet sorting technology. One mutant strain, with a 165.9% increase in Trp titer compared with the parental strain, was successfully screened from a random mutagenesis library. Sequencing results revealed that a total of 10 single-nucleotide polymorphisms were discovered in the genome of the mutant strain, among which CRP(T29K) was proven to significantly increase Trp production through improving the strain's tolerance of the harsh environment during the stationary phase of the fermentation process. Our results indicate that this strategy has great potential for improving the production of other amino acids in Escherichia coli.
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Affiliation(s)
- Yongfei Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, China
| | - Huiling Yuan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, China
| | - Dongqin Ding
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, China
| | - Huina Dong
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, China
| | - Qinhong Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Engineering Laboratory for Industrial Enzymes, Tianjin 300308, China
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24
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Tickner ZJ, Farzan M. Riboswitches for Controlled Expression of Therapeutic Transgenes Delivered by Adeno-Associated Viral Vectors. Pharmaceuticals (Basel) 2021; 14:ph14060554. [PMID: 34200913 PMCID: PMC8230432 DOI: 10.3390/ph14060554] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 05/28/2021] [Accepted: 06/04/2021] [Indexed: 11/16/2022] Open
Abstract
Vectors developed from adeno-associated virus (AAV) are powerful tools for in vivo transgene delivery in both humans and animal models, and several AAV-delivered gene therapies are currently approved for clinical use. However, AAV-mediated gene therapy still faces several challenges, including limited vector packaging capacity and the need for a safe, effective method for controlling transgene expression during and after delivery. Riboswitches, RNA elements which control gene expression in response to ligand binding, are attractive candidates for regulating expression of AAV-delivered transgene therapeutics because of their small genomic footprints and non-immunogenicity compared to protein-based expression control systems. In addition, the ligand-sensing aptamer domains of many riboswitches can be exchanged in a modular fashion to allow regulation by a variety of small molecules, proteins, and oligonucleotides. Riboswitches have been used to regulate AAV-delivered transgene therapeutics in animal models, and recently developed screening and selection methods allow rapid isolation of riboswitches with novel ligands and improved performance in mammalian cells. This review discusses the advantages of riboswitches in the context of AAV-delivered gene therapy, the subsets of riboswitch mechanisms which have been shown to function in human cells and animal models, recent progress in riboswitch isolation and optimization, and several examples of AAV-delivered therapeutic systems which might be improved by riboswitch regulation.
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Affiliation(s)
- Zachary J. Tickner
- Department of Immunology and Microbiology, the Scripps Research Institute, Jupiter, FL 33458, USA;
- Correspondence:
| | - Michael Farzan
- Department of Immunology and Microbiology, the Scripps Research Institute, Jupiter, FL 33458, USA;
- Emmune, Inc., Jupiter, FL 33458, USA
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25
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Kaiser C, Schneider J, Groher F, Suess B, Wachtveitl J. What defines a synthetic riboswitch? - Conformational dynamics of ciprofloxacin aptamers with similar binding affinities but varying regulatory potentials. Nucleic Acids Res 2021; 49:3661-3671. [PMID: 33772594 PMCID: PMC8053125 DOI: 10.1093/nar/gkab166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 02/25/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
Among the many in vitro-selected aptamers derived from SELEX protocols, only a small fraction has the potential to be applied for synthetic riboswitch engineering. Here, we present a comparative study of the binding properties of three different aptamers that bind to ciprofloxacin with similar KD values, yet only two of them can be applied as riboswitches. We used the inherent ligand fluorescence that is quenched upon binding as the reporter signal in fluorescence titration and in time-resolved stopped-flow experiments. Thus, we were able to demonstrate differences in the binding kinetics of regulating and non-regulating aptamers. All aptamers studied underwent a two-step binding mechanism that suggests an initial association step followed by a reorganization of the aptamer to accommodate the ligand. We show that increasing regulatory potential is correlated with a decreasing back-reaction rate of the second binding step, thus resulting in a virtually irreversible last binding step of regulating aptamers. We suggest that a highly favoured structural adaption of the RNA to the ligand during the final binding step is essential for turning an aptamer into a riboswitch. In addition, our results provide an explanation for the fact that so few aptamers with regulating capacity have been found to date. Based on our data, we propose an adjustment of the selection protocol for efficient riboswitch detection.
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Affiliation(s)
- Christoph Kaiser
- Institute for Physical and Theoretical Chemistry, Goethe-Universität Frankfurt, Max-von-Laue-Straße 8, D-60438 Frankfurt am Main, Germany
| | - Jeannine Schneider
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany
| | - Florian Groher
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, Schnittspahnstraße 10, D-64287 Darmstadt, Germany.,Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt, Germany
| | - Josef Wachtveitl
- Institute for Physical and Theoretical Chemistry, Goethe-Universität Frankfurt, Max-von-Laue-Straße 8, D-60438 Frankfurt am Main, Germany
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26
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Ortega AD, Takhaveev V, Vedelaar SR, Long Y, Mestre-Farràs N, Incarnato D, Ersoy F, Olsen LF, Mayer G, Heinemann M. A synthetic RNA-based biosensor for fructose-1,6-bisphosphate that reports glycolytic flux. Cell Chem Biol 2021; 28:1554-1568.e8. [PMID: 33915105 DOI: 10.1016/j.chembiol.2021.04.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/25/2021] [Accepted: 04/06/2021] [Indexed: 12/17/2022]
Abstract
RNA-based sensors for intracellular metabolites are a promising solution to the emerging issue of metabolic heterogeneity. However, their development, i.e., the conversion of an aptamer into an in vivo-functional intracellular metabolite sensor, still harbors challenges. Here, we accomplished this for the glycolytic flux-signaling metabolite, fructose-1,6-bisphosphate (FBP). Starting from in vitro selection of an aptamer, we constructed device libraries with a hammerhead ribozyme as actuator. Using high-throughput screening in yeast with fluorescence-activated cell sorting (FACS), next-generation sequencing, and genetic-environmental perturbations to modulate the intracellular FBP levels, we identified a sensor that generates ratiometric fluorescent readout. An abrogated response in sensor mutants and occurrence of two sensor conformations-revealed by RNA structural probing-indicated in vivo riboswitching activity. Microscopy showed that the sensor can differentiate cells with different glycolytic fluxes within yeast populations, opening research avenues into metabolic heterogeneity. We demonstrate the possibility to generate RNA-based sensors for intracellular metabolites for which no natural metabolite-binding RNA element exits.
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Affiliation(s)
- Alvaro Darío Ortega
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands; Department of Cell Biology, Faculty of Biology, Complutense University of Madrid, 28040 Madrid, Spain.
| | - Vakil Takhaveev
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Silke Roelie Vedelaar
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Yi Long
- LIMES Institute, University of Bonn, 53121 Bonn, Germany; Institute of Biochemistry and Molecular Biology, University of Southern Denmark, DK5230 Odense M, Denmark
| | - Neus Mestre-Farràs
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | - Danny Incarnato
- Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands
| | | | - Lars Folke Olsen
- Institute of Biochemistry and Molecular Biology, University of Southern Denmark, DK5230 Odense M, Denmark
| | - Günter Mayer
- LIMES Institute, University of Bonn, 53121 Bonn, Germany; Center of Aptamer Research & Development, University of Bonn, 53121 Bonn, Germany
| | - Matthias Heinemann
- Molecular Systems Biology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, the Netherlands.
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27
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Aptamers, Riboswitches, and Ribozymes in S. cerevisiae Synthetic Biology. Life (Basel) 2021; 11:life11030248. [PMID: 33802772 PMCID: PMC8002509 DOI: 10.3390/life11030248] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/12/2021] [Accepted: 03/15/2021] [Indexed: 01/09/2023] Open
Abstract
Among noncoding RNA sequences, riboswitches and ribozymes have attracted the attention of the synthetic biology community as circuit components for translation regulation. When fused to aptamer sequences, ribozymes and riboswitches are enabled to interact with chemicals. Therefore, protein synthesis can be controlled at the mRNA level without the need for transcription factors. Potentially, the use of chemical-responsive ribozymes/riboswitches would drastically simplify the design of genetic circuits. In this review, we describe synthetic RNA structures that have been used so far in the yeast Saccharomyces cerevisiae. We present their interaction mode with different chemicals (e.g., theophylline and antibiotics) or proteins (such as the RNase III) and their recent employment into clustered regularly interspaced short palindromic repeats–CRISPR-associated protein 9 (CRISPR-Cas) systems. Particular attention is paid, throughout the whole paper, to their usage and performance into synthetic gene circuits.
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28
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Lyu C, Khan IM, Wang Z. Capture-SELEX for aptamer selection: A short review. Talanta 2021; 229:122274. [PMID: 33838776 DOI: 10.1016/j.talanta.2021.122274] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/18/2022]
Abstract
The emerging aptamer, developed through the systematic evolution of ligands by exponential enrichment (SELEX) process, has revolutionized and facilitated the discoveries in basic research. Among all SELEX technology, Capture-SELEX is a variant of the in vitro selection process, which is suitable for isolating aptamers against small molecules. Capture-SELEX library was developed to enable the immobilization of the oligonucleotides instead of the target molecules during the aptamer selection process. The review provides an update on the recent-advances in this new screening method with particular emphasis on key points of capture protocol and its applications. The limitations and the prospects of the Capture-SELEX are also discussed. We hope that present review will inspire more researchers to understand the selection problems from the perspective of Capture-SELEX. Moreover, it will open new pave to improve the efficiency and success of screening to meet the growing demand for aptasensor discovery in small molecules.
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Affiliation(s)
- Chen Lyu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; School of Food Science and Technology, Jiangnan University, Wuxi, China
| | - Imran Mahmood Khan
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; School of Food Science and Technology, Jiangnan University, Wuxi, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China; Synergetic Innovation Center of Food Safety and Quality Control of Jiangsu Province, China
| | - Zhouping Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China; School of Food Science and Technology, Jiangnan University, Wuxi, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, China; Synergetic Innovation Center of Food Safety and Quality Control of Jiangsu Province, China.
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29
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Kolbe K, Bell AC, Prosser GA, Assmann M, Yang HJ, Forbes HE, Gallucci S, Mayer-Barber KD, Boshoff HI, Barry Iii CE. Development and Optimization of Chromosomally-Integrated Fluorescent Mycobacterium tuberculosis Reporter Constructs. Front Microbiol 2020; 11:591866. [PMID: 33362741 PMCID: PMC7755994 DOI: 10.3389/fmicb.2020.591866] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/13/2020] [Indexed: 11/25/2022] Open
Abstract
Mycobacterium tuberculosis resides in the lungs in various lesion types with unique microenvironmental conditions. This diversity is in line with heterogeneous disease progression and divergent drug efficiency. Fluorescent reporter strains can be used to decipher the micromilieu and to guide future treatment regimens. Current reporters using replicating plasmids, however, are not suitable for long-term mouse infections or studies in non-human primates. Using a combination of recombinant DNA and protein optimization techniques, we have developed reporter strains based on integrative plasmids, which exhibit stimulus-response characteristics and fluorescence intensities comparable to those based on replicating plasmids. We successfully applied the concepts by constructing a multi-color reporter strain able to detect simultaneous changes in environmental pH, Mg2+ concentrations, and protein expression levels.
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Affiliation(s)
- Katharina Kolbe
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Alice C Bell
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Gareth A Prosser
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States.,Drug Discovery Unit, College of Life Sciences, James Black Centre, University of Dundee, Dundee, United Kingdom
| | - Maike Assmann
- Inflammation and Innate Immunity Unit, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Hee-Jeong Yang
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - He Eun Forbes
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Sophia Gallucci
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Katrin D Mayer-Barber
- Inflammation and Innate Immunity Unit, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Helena I Boshoff
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Clifton E Barry Iii
- Tuberculosis Research Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, United States
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30
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Spöring M, Boneberg R, Hartig JS. Aptamer-Mediated Control of Polyadenylation for Gene Expression Regulation in Mammalian Cells. ACS Synth Biol 2020; 9:3008-3018. [PMID: 33108164 DOI: 10.1021/acssynbio.0c00222] [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] [Indexed: 02/06/2023]
Abstract
Small aptamer-based regulatory devices can be designed to control a range of RNA-dependent cellular processes and emerged as promising tools for fine-tuning gene expression in synthetic biology. Here, we design a conceptually new riboswitch device that allows for the conditional regulation of polyadenylation. By making use of ligand-induced sequence occlusion, the system efficiently controls the accessibility of the eukaryotic polyadenylation signal. Undesirable 3'-extended read-through products are counteracted by the downstream insertion of a microRNA target site. We demonstrate the modularity of the system with regard to sensor aptamers and polyadenylation signals used and combine the newly designed riboswitch with well-known aptazymes to yield superior composite systems. In addition, we show that the switches can be used to control alternative polyadenylation. The presented genetic switches require very little coding space and can be easily optimized by rational adjustments of the thermodynamic stability. The polyadenylation riboswitch extends the repertoire of RNA-based regulators and opens new possibilities for the generation of complex synthetic circuits.
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Affiliation(s)
- Maike Spöring
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Ronja Boneberg
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Jörg S. Hartig
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
- Konstanz Research School Chemical Biology, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
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31
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Strobel B, Düchs MJ, Blazevic D, Rechtsteiner P, Braun C, Baum-Kroker KS, Schmid B, Ciossek T, Gottschling D, Hartig JS, Kreuz S. A Small-Molecule-Responsive Riboswitch Enables Conditional Induction of Viral Vector-Mediated Gene Expression in Mice. ACS Synth Biol 2020; 9:1292-1305. [PMID: 32427483 DOI: 10.1021/acssynbio.9b00410] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Adeno-associated viral (AAV) vector-mediated gene therapy holds great potential for future medical applications. However, to facilitate safer and broader applicability and to enable patient-centric care, therapeutic protein expression should be controllable, ideally by an orally administered drug. The use of protein-based systems is considered rather undesirable, due to potential immunogenicity and the limited coding space of AAV. Ligand-dependent riboswitches, in contrast, are small and characterized by an attractive mode-of-action based on mRNA-self-cleavage, independent of coexpressed foreign protein. While a promising approach, switches available to date have only shown moderate potency in animals. In particular, ON-switches that induce transgene expression upon ligand administration so far have achieved rather disappointing results. Here we present the utilization of the previously described tetracycline-dependent ribozyme K19 for controlling AAV-mediated transgene expression in mice. Using this tool switch, we provide first proof for the feasibility of clinically desired key features, including multiorgan functionality, potent regulation (up to 15-fold induction), reversibility, and the possibility to fine-tune and repeatedly induce expression. The systematic assessment of ligand and reporter protein plasma levels further enabled the characterization of pharmacokinetic-pharmacodynamic relationships. Thus, our results strongly support future efforts to develop engineered riboswitches for applications in clinical gene therapy.
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Affiliation(s)
- Benjamin Strobel
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Matthias J. Düchs
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Dragica Blazevic
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Philipp Rechtsteiner
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Clemens Braun
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Katja S. Baum-Kroker
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Bernhard Schmid
- Drug Discovery Sciences, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Thomas Ciossek
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Dirk Gottschling
- Medicinal Chemistry, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
| | - Jörg S. Hartig
- Department of Chemistry, University of Konstanz, Konstanz, 78464, Germany
| | - Sebastian Kreuz
- Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, 88397, Germany
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32
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WANG ZJ, CHEN EN, YANG G, ZHAO XY, QU F. Research Advances of Aptamers Selection for Small Molecule Targets. CHINESE JOURNAL OF ANALYTICAL CHEMISTRY 2020. [DOI: 10.1016/s1872-2040(20)60013-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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33
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Hoang Trung Chau T, Hoang Anh Mai D, Ngoc Pham D, Thi Quynh Le H, Yeol Lee E. Developments of Riboswitches and Toehold Switches for Molecular Detection-Biosensing and Molecular Diagnostics. Int J Mol Sci 2020; 21:E3192. [PMID: 32366036 PMCID: PMC7247568 DOI: 10.3390/ijms21093192] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 12/20/2022] Open
Abstract
Riboswitches and toehold switches are considered to have potential for implementation in various fields, i.e., biosensing, metabolic engineering, and molecular diagnostics. The specific binding, programmability, and manipulability of these RNA-based molecules enable their intensive deployments in molecular detection as biosensors for regulating gene expressions, tracking metabolites, or detecting RNA sequences of pathogenic microorganisms. In this review, we will focus on the development of riboswitches and toehold switches in biosensing and molecular diagnostics. This review introduces the operating principles and the notable design features of riboswitches as well as toehold switches. Moreover, we will describe the advances and future directions of riboswitches and toehold switches in biosensing and molecular diagnostics.
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Affiliation(s)
| | | | | | | | - Eun Yeol Lee
- Department of Chemical Engineering, Kyung Hee University, Yongin-si, Gyeonggi-do 17104, Korea; (T.H.T.C.); (D.H.A.M.); (D.N.P.); (H.T.Q.L.)
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34
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De Nijs Y, De Maeseneire SL, Soetaert WK. 5' untranslated regions: the next regulatory sequence in yeast synthetic biology. Biol Rev Camb Philos Soc 2019; 95:517-529. [PMID: 31863552 DOI: 10.1111/brv.12575] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 11/08/2019] [Accepted: 11/28/2019] [Indexed: 01/10/2023]
Abstract
When developing industrial biotechnology processes, Saccharomyces cerevisiae (baker's yeast or brewer's yeast) is a popular choice as a microbial host. Many tools have been developed in the fields of synthetic biology and metabolic engineering to introduce heterologous pathways and tune their expression in yeast. Such tools mainly focus on controlling transcription, whereas post-transcriptional regulation is often overlooked. Herein we discuss regulatory elements found in the 5' untranslated region (UTR) and their influence on protein synthesis. We provide not only an overall picture, but also a set of design rules on how to engineer a 5' UTR. The reader is also referred to currently available models that allow gene expression to be tuned predictably using different 5' UTRs.
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Affiliation(s)
- Yatti De Nijs
- Faculty of Bioscience Engineering, Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Department Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Sofie L De Maeseneire
- Faculty of Bioscience Engineering, Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Department Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
| | - Wim K Soetaert
- Faculty of Bioscience Engineering, Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Department Biotechnology, Ghent University, Coupure Links 653, 9000, Ghent, Belgium
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35
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Spöring M, Finke M, Hartig JS. Aptamers in RNA-based switches of gene expression. Curr Opin Biotechnol 2019; 63:34-40. [PMID: 31811992 DOI: 10.1016/j.copbio.2019.11.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 11/04/2019] [Accepted: 11/06/2019] [Indexed: 01/25/2023]
Abstract
The ability to control gene expression via small molecule effectors is important in basic research as well as in future gene therapy applications. Although transcription factor-based systems are widely used, they are not well suited for certain applications due to a lack of functionality, limited available coding space, and potential immunogenicity of the regulatory proteins. RNA-based switches fill this gap since they can be designed to respond to effector compounds utilizing ligand-sensing aptamers. These systems are very modular since the aptamer can be combined with a variety of different expression platforms. RNA-based switches have been constructed that allow for controlling gene expression in diverse contexts. Here we discuss latest developments and applications of aptamer-based gene expression switches in eukaryotes.
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Affiliation(s)
- Maike Spöring
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany; Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Monika Finke
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany; Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany
| | - Jörg S Hartig
- Department of Chemistry, University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany; Konstanz Research School Chemical Biology (KoRS-CB), University of Konstanz, Universitätsstraße 10, 78457 Konstanz, Germany.
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36
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Kent R, Dixon N. Contemporary Tools for Regulating Gene Expression in Bacteria. Trends Biotechnol 2019; 38:316-333. [PMID: 31679824 DOI: 10.1016/j.tibtech.2019.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
Abstract
Insights from novel mechanistic paradigms in gene expression control have led to the development of new gene expression systems for bioproduction, control, and sensing applications. Coupled with a greater understanding of synthetic burden and modern creative biodesign approaches, contemporary bacterial gene expression tools and systems are emerging that permit fine-tuning of expression, enabling greater predictability and maximisation of specific productivity, while minimising deleterious effects upon cell viability. These advances have been achieved by using a plethora of regulatory tools, operating at all levels of the so-called 'central dogma' of molecular biology. In this review, we discuss these gene regulation tools in the context of their design, prototyping, integration into expression systems, and biotechnological application.
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Affiliation(s)
- Ross Kent
- Manchester Institute of Biotechnology and School of Chemistry, University of Manchester, Manchester, UK
| | - Neil Dixon
- Manchester Institute of Biotechnology and School of Chemistry, University of Manchester, Manchester, UK.
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37
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Takahashi K, Yokobayashi Y. Reversible Gene Regulation in Mammalian Cells Using Riboswitch-Engineered Vesicular Stomatitis Virus Vector. ACS Synth Biol 2019; 8:1976-1982. [PMID: 31415142 DOI: 10.1021/acssynbio.9b00177] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Synthetic riboswitches based on small molecule-responsive self-cleaving ribozymes (aptazymes) embedded in the untranslated regions (UTRs) allow chemical control of gene expression in mammalian cells. In this work, we used a guanine-responsive aptazyme to control transgene expression from a replication-incompetent vesicular stomatitis virus (VSV) vector. VSV is a nonsegmented, negative-sense, cytoplasmic RNA virus that replicates without DNA intermediates, and its applications for vaccines and oncolytic viral therapy are being explored. By inserting the guanine-activated ribozyme in the 3' UTRs of viral genes and transgenes, GFP expression from the VSV vector in mammalian cells was repressed by as much as 26.8-fold in the presence of guanine. Furthermore, we demonstrated reversible regulation of a transgene (secreted NanoLuc) by adding and withdrawing guanine from the medium over the course of 12 days. In summary, our riboswitch-controlled VSV vector allows robust, long-term, and reversible regulation of gene expression in mammalian cells without the risk of undesirable genomic integration.
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Affiliation(s)
- Kei Takahashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
| | - Yohei Yokobayashi
- Nucleic Acid Chemistry and Engineering Unit, Okinawa Institute of Science and Technology Graduate University, Onna, Okinawa 904 0495, Japan
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Lotz TS, Halbritter T, Kaiser C, Rudolph MM, Kraus L, Groher F, Steinwand S, Wachtveitl J, Heckel A, Suess B. A light-responsive RNA aptamer for an azobenzene derivative. Nucleic Acids Res 2019; 47:2029-2040. [PMID: 30517682 PMCID: PMC6393235 DOI: 10.1093/nar/gky1225] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/22/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022] Open
Abstract
Regulation of complex biological networks has proven to be a key bottleneck in synthetic biology. Interactions between the structurally flexible RNA and various other molecules in the form of riboswitches have shown a high-regulation specificity and efficiency and synthetic riboswitches have filled the toolbox of devices in many synthetic biology applications. Here we report the development of a novel, small molecule binding RNA aptamer, whose binding is dependent on light-induced change of conformation of its small molecule ligand. As ligand we chose an azobenzene because of its reliable photoswitchability and modified it with chloramphenicol for a better interaction with RNA. The synthesis of the ligand 'azoCm' was followed by extensive biophysical analysis regarding its stability and photoswitchability. RNA aptamers were identified after several cycles of in vitro selection and then studied regarding their binding specificity and affinity toward the ligand. We show the successful development of an RNA aptamer that selectively binds to only the trans photoisomer of azoCm with a KD of 545 nM. As the aptamer cannot bind to the irradiated ligand (λ = 365 nm), a light-selective RNA binding system is provided. Further studies may now result in the engineering of a reliable, light-responsible riboswitch.
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Affiliation(s)
- Thea S Lotz
- Technische Universität Darmstadt, Department of Biology, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Thomas Halbritter
- Goethe-University Frankfurt, Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 9, 60438 Frankfurt (M), Germany
| | - Christoph Kaiser
- Goethe-University Frankfurt, Institute for Physical and Theoretical Chemistry, Max-von-Laue-Strasse 7, 60438 Frankfurt (M), Germany
| | - Martin M Rudolph
- Technische Universität Darmstadt, Department of Biology, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Leon Kraus
- Technische Universität Darmstadt, Department of Biology, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Florian Groher
- Technische Universität Darmstadt, Department of Biology, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Sabrina Steinwand
- Goethe-University Frankfurt, Institute for Physical and Theoretical Chemistry, Max-von-Laue-Strasse 7, 60438 Frankfurt (M), Germany
| | - Josef Wachtveitl
- Goethe-University Frankfurt, Institute for Physical and Theoretical Chemistry, Max-von-Laue-Strasse 7, 60438 Frankfurt (M), Germany
| | - Alexander Heckel
- Goethe-University Frankfurt, Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 9, 60438 Frankfurt (M), Germany
| | - Beatrix Suess
- Technische Universität Darmstadt, Department of Biology, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
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39
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Bervoets I, Charlier D. Diversity, versatility and complexity of bacterial gene regulation mechanisms: opportunities and drawbacks for applications in synthetic biology. FEMS Microbiol Rev 2019; 43:304-339. [PMID: 30721976 PMCID: PMC6524683 DOI: 10.1093/femsre/fuz001] [Citation(s) in RCA: 87] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 01/21/2019] [Indexed: 12/15/2022] Open
Abstract
Gene expression occurs in two essential steps: transcription and translation. In bacteria, the two processes are tightly coupled in time and space, and highly regulated. Tight regulation of gene expression is crucial. It limits wasteful consumption of resources and energy, prevents accumulation of potentially growth inhibiting reaction intermediates, and sustains the fitness and potential virulence of the organism in a fluctuating, competitive and frequently stressful environment. Since the onset of studies on regulation of enzyme synthesis, numerous distinct regulatory mechanisms modulating transcription and/or translation have been discovered. Mostly, various regulatory mechanisms operating at different levels in the flow of genetic information are used in combination to control and modulate the expression of a single gene or operon. Here, we provide an extensive overview of the very diverse and versatile bacterial gene regulatory mechanisms with major emphasis on their combined occurrence, intricate intertwinement and versatility. Furthermore, we discuss the potential of well-characterized basal expression and regulatory elements in synthetic biology applications, where they may ensure orthogonal, predictable and tunable expression of (heterologous) target genes and pathways, aiming at a minimal burden for the host.
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Affiliation(s)
- Indra Bervoets
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Daniel Charlier
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
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40
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Boussebayle A, Torka D, Ollivaud S, Braun J, Bofill-Bosch C, Dombrowski M, Groher F, Hamacher K, Suess B. Next-level riboswitch development-implementation of Capture-SELEX facilitates identification of a new synthetic riboswitch. Nucleic Acids Res 2019; 47:4883-4895. [PMID: 30957848 PMCID: PMC6511860 DOI: 10.1093/nar/gkz216] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 03/15/2019] [Accepted: 04/04/2019] [Indexed: 02/06/2023] Open
Abstract
The development of synthetic riboswitches has always been a challenge. Although a number of interesting proof-of-concept studies have been published, almost all of these were performed with the theophylline aptamer. There is no shortage of small molecule-binding aptamers; however, only a small fraction of them are suitable for RNA engineering since a classical SELEX protocol selects only for high-affinity binding but not for conformational switching. We now implemented RNA Capture-SELEX in our riboswitch developmental pipeline to integrate the required selection for high-affinity binding with the equally necessary RNA conformational switching. Thus, we successfully developed a new paromomycin-binding synthetic riboswitch. It binds paromomycin with a KD of 20 nM and can discriminate between closely related molecules both in vitro and in vivo. A detailed structure-function analysis confirmed the predicted secondary structure and identified nucleotides involved in ligand binding. The riboswitch was further engineered in combination with the neomycin riboswitch for the assembly of an orthogonal Boolean NOR logic gate. In sum, our work not only broadens the spectrum of existing RNA regulators, but also signifies a breakthrough in riboswitch development, as the effort required for the design of sensor domains for RNA-based devices will in many cases be much reduced.
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Affiliation(s)
- Adrien Boussebayle
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Daniel Torka
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Sandra Ollivaud
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Johannes Braun
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Cristina Bofill-Bosch
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Max Dombrowski
- Computational Biology and Simulation, Department of Biology, TU Darmstadt, 64287 Darmstadt, Germany
| | - Florian Groher
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Kay Hamacher
- Computational Biology and Simulation, Department of Biology, TU Darmstadt, 64287 Darmstadt, Germany
- Department of Physics, Department of Computer Science, TU Darmstadt, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
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41
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Xia PF, Ling H, Foo JL, Chang MW. Synthetic genetic circuits for programmable biological functionalities. Biotechnol Adv 2019; 37:107393. [PMID: 31051208 DOI: 10.1016/j.biotechadv.2019.04.015] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 04/09/2019] [Accepted: 04/28/2019] [Indexed: 02/06/2023]
Abstract
Living organisms evolve complex genetic networks to interact with the environment. Due to the rapid development of synthetic biology, various modularized genetic parts and units have been identified from these networks. They have been employed to construct synthetic genetic circuits, including toggle switches, oscillators, feedback loops and Boolean logic gates. Building on these circuits, complex genetic machines with capabilities in programmable decision-making could be created. Consequently, these accomplishments have led to novel applications, such as dynamic and autonomous modulation of metabolic networks, directed evolution of biological units, remote and targeted diagnostics and therapies, as well as biological containment methods to prevent release of engineered microorganisms and genetic materials. Herein, we outline the principles in genetic circuit design that have initiated a new chapter in transforming concepts to realistic applications. The features of modularized building blocks and circuit architecture that facilitate realization of circuits for a variety of novel applications are discussed. Furthermore, recent advances and challenges in employing genetic circuits to impart microorganisms with distinct and programmable functionalities are highlighted. We envision that this review gives new insights into the design of synthetic genetic circuits and offers a guideline for the implementation of different circuits in various aspects of biotechnology and bioengineering.
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Affiliation(s)
- Peng-Fei Xia
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Hua Ling
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Jee Loon Foo
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
| | - Matthew Wook Chang
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, 8 Medical Drive, Singapore 117597, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
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Boussebayle A, Groher F, Suess B. RNA-based Capture-SELEX for the selection of small molecule-binding aptamers. Methods 2019; 161:10-15. [PMID: 30953759 DOI: 10.1016/j.ymeth.2019.04.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 11/16/2022] Open
Abstract
Despite their wide applicability, the selection of small molecule-binding RNA aptamers with both high affinity binding and specificity is still challenging. Aptamers that excel at both binding and structure switching are particularly rare and difficult to find. Here, we present the protocol of a Capture-SELEX that specifically allows the in vitro selection of small-molecule binding aptamers, which are essential building blocks for the design process of synthetic riboswitches and biosensors. Moreover, we provide a comparative overview of our proposed methodology versus alternative in vitro selection protocols with a special focus on the design of the pool. Finally, we have included detailed notes to point out useful tips and pitfalls for future application.
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Affiliation(s)
- Adrien Boussebayle
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Florian Groher
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, TU Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany.
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43
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Auxillos JY, Garcia-Ruiz E, Jones S, Li T, Jiang S, Dai J, Cai Y. Multiplex Genome Engineering for Optimizing Bioproduction in Saccharomyces cerevisiae. Biochemistry 2019; 58:1492-1500. [DOI: 10.1021/acs.biochem.8b01086] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jamie Y. Auxillos
- Manchester Institute of Biotechnology (MIB), School of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- School of Biological Sciences, University of Edinburgh, King’s Buildings, Edinburgh EH9 3JY, United Kingdom
| | - Eva Garcia-Ruiz
- Manchester Institute of Biotechnology (MIB), School of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Sally Jones
- Manchester Institute of Biotechnology (MIB), School of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Tianyi Li
- Center for Synthetic Genomics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Shuangying Jiang
- Center for Synthetic Genomics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Junbiao Dai
- Center for Synthetic Genomics, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Yizhi Cai
- Manchester Institute of Biotechnology (MIB), School of Chemistry, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
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44
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Galizi R, Jaramillo A. Engineering CRISPR guide RNA riboswitches for in vivo applications. Curr Opin Biotechnol 2019; 55:103-113. [PMID: 30265865 DOI: 10.1016/j.copbio.2018.08.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 08/13/2018] [Accepted: 08/16/2018] [Indexed: 02/07/2023]
Abstract
CRISPR-based genome editing provides a simple and scalable toolbox for a variety of therapeutic and biotechnology applications. Whilst the fundamental properties of CRISPR proved easily transferable from the native prokaryotic hosts to eukaryotic and multicellular organisms, the tight control of the CRISPR-editing activity remains a major challenge. Here we summarise recent developments of CRISPR and riboswitch technologies and recommend novel functionalised synthetic-gRNA (sgRNA) designs to achieve inducible and spatiotemporal regulation of CRISPR-based genetic editors in response to cellular or extracellular stimuli. We believe that future advances of these tools will have major implications for both basic and applied research, spanning from fundamental genetic studies and synthetic biology to genetic editing and gene therapy.
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Affiliation(s)
- Roberto Galizi
- Department of Life Sciences, Imperial College London, London, United Kingdom.
| | - Alfonso Jaramillo
- Warwick Integrative Synthetic Biology Centre (WISB) and School of Life Sciences, University of Warwick, CV4 7AL Coventry, United Kingdom; ISSB, CNRS, Univ Evry, CEA, Université Paris-Saclay, 91025 Evry, France; Institute for Integrative Systems Biology (I2SysBio), University of Valencia-CSIC, 46980 Paterna, Spain.
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45
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Groher AC, Jager S, Schneider C, Groher F, Hamacher K, Suess B. Tuning the Performance of Synthetic Riboswitches using Machine Learning. ACS Synth Biol 2019; 8:34-44. [PMID: 30513199 DOI: 10.1021/acssynbio.8b00207] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Riboswitch development for clinical, technological, and synthetic biology applications constantly seeks to optimize regulatory behavior. Here, we present a machine learning approach to improve the regulation of a tetracycline (tc)-dependent riboswitch device composed of two individual tc aptamers. We developed a bioinformatics model that combines random forest analysis with a convolutional neural network to predict the switching behavior of such tandem riboswitches. We found that both biophysical parameters and the hydrogen bond pattern influence regulation. Our new design pipeline led to significant improvement of the tc riboswitch device with a dynamic range extension from 8.5 to 40-fold. We are confident that our novel method not only results in an excellent tc-dependent riboswitch device but further holds great promise and potential for the optimization of other riboswitches.
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Abstract
RNA is a versatile biomolecule capable of transferring information, taking on distinct three-dimensional shapes, and reacting to ambient conditions. RNA molecules utilize a wide range of mechanisms to control gene expression. An example of such regulation is riboswitches. Consisting exclusively of RNA, they are able to control important metabolic processes, thus providing an elegant and efficient RNA-only regulation system. Existing across all domains of life, riboswitches appear to represent one of the most highly conserved mechanisms for the regulation of a broad range of biochemical pathways. Through binding of a wide range of small-molecule ligands to their so-called aptamer domain, riboswitches undergo a conformational change in their downstream "expression platform." In consequence, the pattern of gene expression changes, which in turn results in increased or decreased protein production. Riboswitches unite the sensing and transduction of a signal that can directly be coupled to the metabolism of the cell; thus they constitute a very potent regulatory mechanism for many organisms. Highly specific RNA-binding domains not only occur in vivo but can also be evolved by means of the SELEX (systematic evolution of ligands by exponential enrichment) method, which allows in vitro selection of aptamers against almost any ligand. Coupling of these aptamers with an expression platform has led to the development of synthetic riboswitches, a highly active research field of great relevance and immense potential. The aim of this review is to summarize developments in the riboswitch field over the last decade and address key questions of recent research.
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47
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Jaeger J, Groher F, Stamm J, Spiehl D, Braun J, Dörsam E, Suess B. Characterization and Inkjet Printing of an RNA Aptamer for Paper-Based Biosensing of Ciprofloxacin. BIOSENSORS 2019; 9:E7. [PMID: 30609709 PMCID: PMC6468496 DOI: 10.3390/bios9010007] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 12/24/2018] [Accepted: 12/26/2018] [Indexed: 12/25/2022]
Abstract
The excessive use of antibiotics in food-producing animals causes a steady rise of multiple antibiotic resistance in foodborne bacteria. Next to sulfonamides, the most common antibiotics groups are fluoroquinolones, aminoglycosides, and ß-lactams. Therefore, there is a need for a quick, efficient, and low-cost detection procedure for antibiotics. In this study, we propose an inkjet-printed aptamer-based biosensor developed for the detection of the fluoroquinolone ciprofloxacin. Due to their extraordinary high affinity and specificity, aptamers are already widely used in various applications. Here we present a ciprofloxacin-binding RNA aptamer developed by systematic evolution of ligands by exponential enrichment (SELEX). We characterized the secondary structure of the aptamer and determined the KD to 36 nM that allow detection of antibiotic contamination in a relevant range. We demonstrate that RNA aptamers can be inkjet-printed, dried, and resolved while keeping their functionality consistently intact. With this proof of concept, we are paving the way for a potential range of additional aptamer-based, printable biosensors.
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Affiliation(s)
- Jeannine Jaeger
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
| | - Florian Groher
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
| | - Jacqueline Stamm
- Institute for Printing Science and Technology, Technische Universität Darmstadt, 64289 Darmstadt, Germany.
| | - Dieter Spiehl
- Institute for Printing Science and Technology, Technische Universität Darmstadt, 64289 Darmstadt, Germany.
| | - Johannes Braun
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
| | - Edgar Dörsam
- Institute for Printing Science and Technology, Technische Universität Darmstadt, 64289 Darmstadt, Germany.
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany.
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48
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Page K, Shaffer J, Lin S, Zhang M, Liu JM. Engineering Riboswitches in Vivo Using Dual Genetic Selection and Fluorescence-Activated Cell Sorting. ACS Synth Biol 2018; 7:2000-2006. [PMID: 30119599 DOI: 10.1021/acssynbio.8b00099] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Riboswitches, noncoding RNAs that bind a small molecule effector to control gene expression at the level of transcription or translation, are uniquely suited to meet challenges in synthetic biology. To expand the limited set of existing riboswitches, we developed a riboswitch discovery platform that couples dual genetic selection and fluorescence-activated cell sorting to identify novel riboswitches from a 108 random-sequence library in which the aptamer domain of the ThiM#2 riboswitch was replaced with an N40 sequence. In a proof-of-principle validation, we identified novel riboswitches for the small molecule theophylline. Our best riboswitch (Hit 3-5) displays 2.3-fold activation of downstream gene expression in the presence of theophylline. Random mutagenesis of Hit 3-5, coupled with selections and screens, afforded improved riboswitches displaying nearly 3-fold activation. To the best of our knowledge, this is the first report of in vivo directed evolution of an aptamer domain to generate a functional riboswitch.
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Affiliation(s)
- Katharine Page
- Department of Chemistry, Pomona College, 645 N. College Avenue, Claremont, California 91711, United States
| | - Jeremy Shaffer
- Department of Chemistry, Pomona College, 645 N. College Avenue, Claremont, California 91711, United States
| | - Samuel Lin
- Department of Chemistry, Pomona College, 645 N. College Avenue, Claremont, California 91711, United States
| | - Mark Zhang
- Department of Chemistry, Pomona College, 645 N. College Avenue, Claremont, California 91711, United States
| | - Jane M. Liu
- Department of Chemistry, Pomona College, 645 N. College Avenue, Claremont, California 91711, United States
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