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Haynes KA, Andrews LB, Beisel CL, Chappell J, Cuba Samaniego CE, Dueber JE, Dunlop MJ, Franco E, Lucks JB, Noireaux V, Savage DF, Silver PA, Smanski M, Young E. Ten Years of the Synthetic Biology Summer Course at Cold Spring Harbor Laboratory. ACS Synth Biol 2024; 13:2635-2642. [PMID: 39300908 PMCID: PMC11421210 DOI: 10.1021/acssynbio.4c00276] [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: 09/22/2024]
Abstract
The Cold Spring Harbor Laboratory (CSHL) Summer Course on Synthetic Biology, established in 2013, has emerged as a premier platform for immersive education and research in this dynamic field. Rooted in CSHL's rich legacy of biological discovery, the course offers a comprehensive exploration of synthetic biology's fundamentals and applications. Led by a consortium of faculty from diverse institutions, the course structure seamlessly integrates practical laboratory sessions, exploratory research rotations, and enriching seminars by leaders in the field. Over the years, the curriculum has evolved to cover essential topics such as cell-free transcription-translation, DNA construction, computational modeling of gene circuits, engineered gene regulation, and CRISPR technologies. In this review, we describe the history, development, and structure of the course, and discuss how elements of the course might inform the development of other short courses in synthetic biology. We also demonstrate the course's impact beyond the lab with a summary of alumni contributions to research, education, and entrepreneurship. Through these efforts, the CSHL Summer Course on Synthetic Biology remains at the forefront of shaping the next generation of synthetic biologists.
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Affiliation(s)
- Karmella A Haynes
- Wallace H. Coulter Department of Biomedical Engineering, Emory University, Atlanta, Georgia 30345, United States
| | - Lauren B Andrews
- Department of Chemical Engineering, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Chase L Beisel
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
- Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
| | - James Chappell
- Biosciences Department, Rice University, Houston, Texas 77005, United States
| | - Christian E Cuba Samaniego
- Department of Computational Biology, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - John E Dueber
- Department of Bioengineering, University of California Berkeley, Berkeley, California 94720, United States
| | - Mary J Dunlop
- Biomedical Engineering, Boston University, Boston, Massachusetts 02215, United States
| | - Elisa Franco
- Mechanical and Aerospace Engineering, Bioengineering, University of California, Los Angeles, California 90095, United States
| | - Julius B Lucks
- Department of Chemical and Biological Engineering and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - David F Savage
- Department of Molecular and Cell Biology, University of California Berkeley, Berkeley, California 94720, United States
- Howard Hughes Medical Institute, University of California Berkeley, Berkeley, California 94720, United States
| | - Pamela A Silver
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Michael Smanski
- Department of Biochemistry, Molecular Biology, and Biophysics and Biotechnology Institute, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Eric Young
- Chemical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States
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2
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Koksaldi I, Park D, Atilla A, Kang H, Kim J, Seker UOS. RNA-Based Sensor Systems for Affordable Diagnostics in the Age of Pandemics. ACS Synth Biol 2024; 13:1026-1037. [PMID: 38588603 PMCID: PMC11036506 DOI: 10.1021/acssynbio.3c00698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 03/25/2024] [Accepted: 03/25/2024] [Indexed: 04/10/2024]
Abstract
In the era of the COVID-19 pandemic, the significance of point-of-care (POC) diagnostic tools has become increasingly vital, driven by the need for quick and precise virus identification. RNA-based sensors, particularly toehold sensors, have emerged as promising candidates for POC detection systems due to their selectivity and sensitivity. Toehold sensors operate by employing an RNA switch that changes the conformation when it binds to a target RNA molecule, resulting in a detectable signal. This review focuses on the development and deployment of RNA-based sensors for POC viral RNA detection with a particular emphasis on toehold sensors. The benefits and limits of toehold sensors are explored, and obstacles and future directions for improving their performance within POC detection systems are presented. The use of RNA-based sensors as a technology for rapid and sensitive detection of viral RNA holds great potential for effectively managing (dealing/coping) with present and future pandemics in resource-constrained settings.
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Affiliation(s)
- Ilkay
Cisil Koksaldi
- UNAM
− Institute of Materials Science and Nanotechnology, National
Nanotechnology Research Center (UNAM), Bilkent
University, Ankara 06800, Turkey
| | - Dongwon Park
- Department
of Life Sciences, Pohang University of Science
and Technology, Pohang 37673, South Korea
| | - Abdurahman Atilla
- UNAM
− Institute of Materials Science and Nanotechnology, National
Nanotechnology Research Center (UNAM), Bilkent
University, Ankara 06800, Turkey
| | - Hansol Kang
- Department
of Life Sciences, Pohang University of Science
and Technology, Pohang 37673, South Korea
| | - Jongmin Kim
- Department
of Life Sciences, Pohang University of Science
and Technology, Pohang 37673, South Korea
| | - Urartu Ozgur Safak Seker
- UNAM
− Institute of Materials Science and Nanotechnology, National
Nanotechnology Research Center (UNAM), Bilkent
University, Ankara 06800, Turkey
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3
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Franco RAL, Brenner G, Zocca VFB, de Paiva GB, Lima RN, Rech EL, Amaral DT, Lins MRCR, Pedrolli DB. Signal Amplification for Cell-Free Biosensors, an Analog-to-Digital Converter. ACS Synth Biol 2023; 12:2819-2826. [PMID: 37792474 DOI: 10.1021/acssynbio.3c00227] [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: 10/06/2023]
Abstract
Toehold switches are biosensors useful for the detection of endogenous and environmental RNAs. They have been successfully engineered to detect virus RNAs in cell-free gene expression reactions. Their inherent sequence programmability makes engineering a fast and predictable process. Despite improvements in the design, toehold switches suffer from leaky translation in the OFF state, which compromises the fold change and sensitivity of the biosensor. To address this, we constructed and tested signal amplification circuits for three toehold switches triggered by Dengue and SARS-CoV-2 RNAs and an artificial RNA. The serine integrase circuit efficiently contained leakage, boosted the expression fold change from OFF to ON, and decreased the detection limit of the switches by 3-4 orders of magnitude. Ultimately, the integrase circuit converted the analog switches' signals into digital-like output. The circuit is broadly useful for biosensors and eliminates the hard work of designing and testing multiple switches to find the best possible performer.
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Affiliation(s)
- Rafael A L Franco
- Universidade Estadual Paulista (UNESP), School of Pharmaceutical Sciences, Department of Bioprocess Engineering and Biotechnology, Rodovia Araraquara-Jau km1, 14800-903 Araraquara, Brazil
| | - Gabriel Brenner
- Universidade Estadual Paulista (UNESP), School of Pharmaceutical Sciences, Department of Bioprocess Engineering and Biotechnology, Rodovia Araraquara-Jau km1, 14800-903 Araraquara, Brazil
| | - Vitória F B Zocca
- Universidade Estadual Paulista (UNESP), School of Pharmaceutical Sciences, Department of Bioprocess Engineering and Biotechnology, Rodovia Araraquara-Jau km1, 14800-903 Araraquara, Brazil
| | - Gabriela B de Paiva
- Universidade Estadual Paulista (UNESP), School of Pharmaceutical Sciences, Department of Bioprocess Engineering and Biotechnology, Rodovia Araraquara-Jau km1, 14800-903 Araraquara, Brazil
| | - Rayane N Lima
- Embrapa Genetic Resources and Biotechnology, National Institute of Science and Technology - Synthetic Biology, 70770-917 Brasília, Brazil
| | - Elibio L Rech
- Embrapa Genetic Resources and Biotechnology, National Institute of Science and Technology - Synthetic Biology, 70770-917 Brasília, Brazil
| | - Danilo T Amaral
- Federal University of ABC (UFABC), Center for Natural and Human Sciences, Campus Santo André, Avenida dos Estados 5001, 09210-580 Santo André, Brazil
| | - Milca R C R Lins
- Federal University of ABC (UFABC), Center for Natural and Human Sciences, Campus Santo André, Avenida dos Estados 5001, 09210-580 Santo André, Brazil
| | - Danielle B Pedrolli
- Universidade Estadual Paulista (UNESP), School of Pharmaceutical Sciences, Department of Bioprocess Engineering and Biotechnology, Rodovia Araraquara-Jau km1, 14800-903 Araraquara, Brazil
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4
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Zhang XE, Liu C, Dai J, Yuan Y, Gao C, Feng Y, Wu B, Wei P, You C, Wang X, Si T. Enabling technology and core theory of synthetic biology. SCIENCE CHINA. LIFE SCIENCES 2023; 66:1742-1785. [PMID: 36753021 PMCID: PMC9907219 DOI: 10.1007/s11427-022-2214-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 10/04/2022] [Indexed: 02/09/2023]
Abstract
Synthetic biology provides a new paradigm for life science research ("build to learn") and opens the future journey of biotechnology ("build to use"). Here, we discuss advances of various principles and technologies in the mainstream of the enabling technology of synthetic biology, including synthesis and assembly of a genome, DNA storage, gene editing, molecular evolution and de novo design of function proteins, cell and gene circuit engineering, cell-free synthetic biology, artificial intelligence (AI)-aided synthetic biology, as well as biofoundries. We also introduce the concept of quantitative synthetic biology, which is guiding synthetic biology towards increased accuracy and predictability or the real rational design. We conclude that synthetic biology will establish its disciplinary system with the iterative development of enabling technologies and the maturity of the core theory.
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Affiliation(s)
- Xian-En Zhang
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, 518055, China.
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Chenli Liu
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, 518055, China.
- Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Junbiao Dai
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, 518055, China.
- Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Yingjin Yuan
- Frontiers Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering (Ministry of Education), School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
| | - Caixia Gao
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Yan Feng
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Bian Wu
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
| | - Ping Wei
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, 518055, China.
- Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
| | - Chun You
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
| | - Xiaowo Wang
- Ministry of Education Key Laboratory of Bioinformatics; Center for Synthetic and Systems Biology; Bioinformatics Division, Beijing National Research Center for Information Science and Technology; Department of Automation, Tsinghua University, Beijing, 100084, China.
| | - Tong Si
- Faculty of Synthetic Biology, Shenzhen Institute of Advanced Technology, Shenzhen, 518055, China.
- Institute of Synthetic Biology, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China.
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5
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Yue K, Chen J, Li Y, Kai L. Advancing synthetic biology through cell-free protein synthesis. Comput Struct Biotechnol J 2023; 21:2899-2908. [PMID: 37216017 PMCID: PMC10196276 DOI: 10.1016/j.csbj.2023.05.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 05/03/2023] [Accepted: 05/03/2023] [Indexed: 05/24/2023] Open
Abstract
The rapid development of synthetic biology has enabled the production of compounds with revolutionary improvements in biotechnology. DNA manipulation tools have expedited the engineering of cellular systems for this purpose. Nonetheless, the inherent constraints of cellular systems persist, imposing an upper limit on mass and energy conversion efficiencies. Cell-free protein synthesis (CFPS) has demonstrated its potential to overcome these inherent constraints and has been instrumental in the further advancement of synthetic biology. Via the removal of the cell membranes and redundant parts of cells, CFPS has provided flexibility in directly dissecting and manipulating the Central Dogma with rapid feedback. This mini-review summarizes recent achievements of the CFPS technique and its application to a wide range of synthetic biology projects, such as minimal cell assembly, metabolic engineering, and recombinant protein production for therapeutics, as well as biosensor development for in vitro diagnostics. In addition, current challenges and future perspectives in developing a generalized cell-free synthetic biology are outlined.
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Affiliation(s)
- Ke Yue
- School of Life Sciences, Jiangsu Normal University, Xuzhou 22116, China
| | - Junyu Chen
- School of Life Sciences, Jiangsu Normal University, Xuzhou 22116, China
| | - Yingqiu Li
- School of Life Sciences, Jiangsu Normal University, Xuzhou 22116, China
| | - Lei Kai
- School of Life Sciences, Jiangsu Normal University, Xuzhou 22116, China
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6
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Schaffter SW, Wintenberg ME, Murphy TM, Strychalski EA. Design Approaches to Expand the Toolkit for Building Cotranscriptionally Encoded RNA Strand Displacement Circuits. ACS Synth Biol 2023; 12:1546-1561. [PMID: 37134273 DOI: 10.1021/acssynbio.3c00079] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Cotranscriptionally encoded RNA strand displacement (ctRSD) circuits are an emerging tool for programmable molecular computation, with potential applications spanning in vitro diagnostics to continuous computation inside living cells. In ctRSD circuits, RNA strand displacement components are continuously produced together via transcription. These RNA components can be rationally programmed through base pairing interactions to execute logic and signaling cascades. However, the small number of ctRSD components characterized to date limits circuit size and capabilities. Here, we characterize over 200 ctRSD gate sequences, exploring different input, output, and toehold sequences and changes to other design parameters, including domain lengths, ribozyme sequences, and the order in which gate strands are transcribed. This characterization provides a library of sequence domains for engineering ctRSD components, i.e., a toolkit, enabling circuits with up to 4-fold more inputs than previously possible. We also identify specific failure modes and systematically develop design approaches that reduce the likelihood of failure across different gate sequences. Lastly, we show the ctRSD gate design is robust to changes in transcriptional encoding, opening a broad design space for applications in more complex environments. Together, these results deliver an expanded toolkit and design approaches for building ctRSD circuits that will dramatically extend capabilities and potential applications.
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Affiliation(s)
- Samuel W Schaffter
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Molly E Wintenberg
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Terence M Murphy
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
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7
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Vezeau GE, Gadila LR, Salis HM. Automated design of protein-binding riboswitches for sensing human biomarkers in a cell-free expression system. Nat Commun 2023; 14:2416. [PMID: 37105971 PMCID: PMC10140043 DOI: 10.1038/s41467-023-38098-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
Cell-free genetically encoded biosensors have been developed to detect small molecules and nucleic acids, but they have yet to be reliably engineered to detect proteins. Here we develop an automated platform to convert protein-binding RNA aptamers into riboswitch sensors that operate within low-cost cell-free assays. We demonstrate the platform by engineering 35 protein-sensing riboswitches for human monomeric C-reactive protein, human interleukin-32γ, and phage MS2 coat protein. The riboswitch sensors regulate output expression levels by up to 16-fold with input protein concentrations within the human serum range. We identify two distinct mechanisms governing riboswitch-mediated regulation of translation rates and leverage computational analysis to refine the protein-binding aptamer regions, improving design accuracy. Overall, we expand the cell-free sensor toolbox and demonstrate how computational design is used to develop protein-sensing riboswitches with future applications as low-cost medical diagnostics.
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Affiliation(s)
- Grace E Vezeau
- Department of Agricultural and Biological Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Lipika R Gadila
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802, USA
| | - Howard M Salis
- Department of Agricultural and Biological Engineering, Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, 16802, USA.
- Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, 16802, USA.
- Huck Institute Bioinformatics and Genomics Graduate Program, Pennsylvania State University, University Park, PA, 16802, USA.
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8
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Yue K, Li Y, Cao M, Shen L, Gu J, Kai L. Bottom-Up Synthetic Biology Using Cell-Free Protein Synthesis. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2023; 185:1-20. [PMID: 37526707 DOI: 10.1007/10_2023_232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Technical advances in biotechnology have greatly accelerated the development of bottom-up synthetic biology. Unlike top-down approaches, bottom-up synthetic biology focuses on the construction of a minimal cell from scratch and the application of these principles to solve challenges. Cell-free protein synthesis (CFPS) systems provide minimal machinery for transcription and translation, from either a fractionated cell lysate or individual purified protein elements, thus speeding up the development of synthetic cell projects. In this review, we trace the history of the cell-free technique back to the first in vitro fermentation experiment using yeast cell lysate. Furthermore, we summarized progresses of individual cell mimicry modules, such as compartmentalization, gene expression regulation, energy regeneration and metabolism, growth and division, communication, and motility. Finally, current challenges and future perspectives on the field are outlined.
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Affiliation(s)
- Ke Yue
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Yingqiu Li
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Mengjiao Cao
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Lulu Shen
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Jingsheng Gu
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China
| | - Lei Kai
- School of Life Sciences, Jiangsu Normal University, Xuzhou, China.
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9
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Choi YN, Cho N, Lee K, Gwon DA, Lee JW, Lee J. Programmable Synthesis of Biobased Materials Using Cell-Free Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203433. [PMID: 36108274 DOI: 10.1002/adma.202203433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Motivated by the intricate mechanisms underlying biomolecule syntheses in cells that chemistry is currently unable to mimic, researchers have harnessed biological systems for manufacturing novel materials. Cell-free systems (CFSs) utilizing the bioactivity of transcriptional and translational machineries in vitro are excellent tools that allow supplementation of exogenous materials for production of innovative materials beyond the capability of natural biological systems. Herein, recent studies that have advanced the ability to expand the scope of biobased materials using CFS are summarized and approaches enabling the production of high-value materials, prototyping of genetic parts and modules, and biofunctionalization are discussed. By extending the reach of chemical and enzymatic reactions complementary to cellular materials, CFSs provide new opportunities at the interface of materials science and synthetic biology.
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Affiliation(s)
- Yun-Nam Choi
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Namjin Cho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kanghun Lee
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Da-Ae Gwon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jeong Wook Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Joongoo Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
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10
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Ranji Charna A, Des Soye BJ, Ntai I, Kelleher NL, Jewett MC. An efficient cell-free protein synthesis platform for producing proteins with pyrrolysine-based noncanonical amino acids. Biotechnol J 2022; 17:e2200096. [PMID: 35569121 PMCID: PMC9452482 DOI: 10.1002/biot.202200096] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/04/2022] [Accepted: 05/09/2022] [Indexed: 11/08/2022]
Abstract
Incorporation of noncanonical amino acids (ncAAs) into proteins opens new opportunities in biotechnology and synthetic biology. Pyrrolysine (Pyl)-based ncAAs are some of the most predominantly used, but expression systems suffer from low yields. Here, we report a highly efficient cell-free protein synthesis (CFPS) platform for site-specific incorporation of Pyl-based ncAAs into proteins using amber suppression. This platform is based on cellular extracts derived from genomically recoded Escherichia coli lacking release factor 1 and enhanced through deletion of endonuclease A. To enable ncAA incorporation, orthogonal translation system (OTS) components (i.e., the orthogonal transfer RNA [tRNA] and orthogonal aminoacyl tRNA synthetase) were coexpressed in the source strain prior to lysis and the orthogonal tRNACUA Pyl that decodes the amber codon was further enriched in the CFPS reaction via co-synthesis with the product. Using this platform, we demonstrate production of up to 442 ± 23 µg/mL modified superfolder green fluorescent protein (sfGFP) containing a single Pyl-based ncAA at high (>95%) suppression efficiency, as well as sfGFP variants harboring multiple, identical ncAAs. Our CFPS platform can be used for the synthesis of modified proteins containing multiple precisely positioned, genetically encoded Pyl-based ncAAs. We anticipate that it will facilitate more general use of CFPS in synthetic biology.
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Affiliation(s)
- Arnaz Ranji Charna
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Benjamin J Des Soye
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Ioanni Ntai
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Neil L Kelleher
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Department of Chemistry, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
- Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Northwestern University, Chicago, Illinois, USA
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11
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Romantseva E, Alperovich N, Ross D, Lund SP, Strychalski EA. Effects of DNA template preparation on variability in cell-free protein production. Synth Biol (Oxf) 2022; 7:ysac015. [PMID: 36046152 PMCID: PMC9425043 DOI: 10.1093/synbio/ysac015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 07/01/2022] [Accepted: 08/12/2022] [Indexed: 08/08/2023] Open
Abstract
DNA templates for protein production remain an unexplored source of variability in the performance of cell-free expression (CFE) systems. To characterize this variability, we investigated the effects of two common DNA extraction methodologies, a postprocessing step and manual versus automated preparation on protein production using CFE. We assess the concentration of the DNA template, the quality of the DNA template in terms of physical damage and the quality of the DNA solution in terms of purity resulting from eight DNA preparation workflows. We measure the variance in protein titer and rate of protein production in CFE reactions associated with the biological replicate of the DNA template, the technical replicate DNA solution prepared with the same workflow and the measurement replicate of nominally identical CFE reactions. We offer practical guidance for preparing and characterizing DNA templates to achieve acceptable variability in CFE performance.
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Affiliation(s)
| | - Nina Alperovich
- National Institute of Standards and Technology, Gaithersburg, MD USA
| | - David Ross
- National Institute of Standards and Technology, Gaithersburg, MD USA
| | - Steven P Lund
- National Institute of Standards and Technology, Gaithersburg, MD USA
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12
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Rhea KA, McDonald ND, Cole SD, Noireaux V, Lux MW, Buckley PE. Variability in cell-free expression reactions can impact qualitative genetic circuit characterization. Synth Biol (Oxf) 2022; 7:ysac011. [PMID: 35966404 PMCID: PMC9365049 DOI: 10.1093/synbio/ysac011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/24/2022] [Accepted: 08/01/2022] [Indexed: 09/21/2023] Open
Abstract
Cell-free expression systems provide a suite of tools that are used in applications from sensing to biomanufacturing. One of these applications is genetic circuit prototyping, where the lack of cloning is required and a high degree of control over reaction components and conditions enables rapid testing of design candidates. Many studies have shown utility in the approach for characterizing genetic regulation elements, simple genetic circuit motifs, protein variants or metabolic pathways. However, variability in cell-free expression systems is a known challenge, whether between individuals, laboratories, instruments, or batches of materials. While the issue of variability has begun to be quantified and explored, little effort has been put into understanding the implications of this variability. For genetic circuit prototyping, it is unclear when and how significantly variability in reaction activity will impact qualitative assessments of genetic components, e.g. relative activity between promoters. Here, we explore this question by assessing DNA titrations of seven genetic circuits of increasing complexity using reaction conditions that ostensibly follow the same protocol but vary by person, instrument and material batch. Although the raw activities vary widely between the conditions, by normalizing within each circuit across conditions, reasonably consistent qualitative performance emerges for the simpler circuits. For the most complex case involving expression of three proteins, we observe a departure from this qualitative consistency, offering a provisional cautionary line where normal variability may disrupt reliable reuse of prototyping results. Our results also suggest that a previously described closed loop controller circuit may help to mitigate such variability, encouraging further work to design systems that are robust to variability. Graphical Abstract.
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Affiliation(s)
- Katherine A Rhea
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Nathan D McDonald
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Stephanie D Cole
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Matthew W Lux
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Patricia E Buckley
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
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13
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Copeland CE, Kim J, Copeland PL, Heitmeier CJ, Kwon YC. Characterizing a New Fluorescent Protein for a Low Limit of Detection Sensing in the Cell-Free System. ACS Synth Biol 2022; 11:2800-2810. [PMID: 35850511 PMCID: PMC9396652 DOI: 10.1021/acssynbio.2c00180] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cell-free protein synthesis-based biosensors have been developed as highly accurate, low-cost biosensors. However, since most biomarkers exist at low concentrations in various types of biopsies, the biosensor's dynamic range must be increased in the system to achieve low limits of detection necessary while deciphering from higher background signals. Many attempts to increase the dynamic range have relied on amplifying the input signal from the analyte, which can lead to complications of false positives. In this study, we aimed to increase the protein synthesis capability of the cell-free protein synthesis system and the output signal of the reporter protein to achieve a lower limit of detection. We utilized a new fluorescent protein, mNeonGreen, which produces a higher output than those commonly used in cell-free biosensors. Optimizations of DNA sequence and the subsequent cell-free protein synthesis reaction conditions allowed characterizing protein expression variability by given DNA template types, reaction environment, and storage additives that cause the greatest time constraint on designing the cell-free biosensor. Finally, we characterized the fluorescence kinetics of mNeonGreen compared to the commonly used reporter protein, superfolder green fluorescent protein. We expect that this finely tuned cell-free protein synthesis platform with the new reporter protein can be used with sophisticated synthetic gene circuitry networks to increase the dynamic range of a cell-free biosensor to reach lower detection limits and reduce the false-positive proportion.
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Affiliation(s)
- Caroline E Copeland
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Jeehye Kim
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Pearce L Copeland
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Chloe J Heitmeier
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States
| | - Yong-Chan Kwon
- Department of Biological and Agricultural Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, United States.,Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, United States
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14
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A microfluidic optimal experimental design platform for forward design of cell-free genetic networks. Nat Commun 2022; 13:3626. [PMID: 35750678 PMCID: PMC9232554 DOI: 10.1038/s41467-022-31306-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/14/2022] [Indexed: 12/20/2022] Open
Abstract
Cell-free protein synthesis has been widely used as a “breadboard” for design of synthetic genetic networks. However, due to a severe lack of modularity, forward engineering of genetic networks remains challenging. Here, we demonstrate how a combination of optimal experimental design and microfluidics allows us to devise dynamic cell-free gene expression experiments providing maximum information content for subsequent non-linear model identification. Importantly, we reveal that applying this methodology to a library of genetic circuits, that share common elements, further increases the information content of the data resulting in higher accuracy of model parameters. To show modularity of model parameters, we design a pulse decoder and bistable switch, and predict their behaviour both qualitatively and quantitatively. Finally, we update the parameter database and indicate that network topology affects parameter estimation accuracy. Utilizing our methodology provides us with more accurate model parameters, a necessity for forward engineering of complex genetic networks. Characterization of cell-free genetic networks is inherently difficult. Here the authors use optimal experimental design and microfluidics to improve characterization, demonstrating modularity and predictability of parts in applied test cases.
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15
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Liu B, Cuba Samaniego C, Bennett M, Chappell J, Franco E. RNA Compensation: A Positive Feedback Insulation Strategy for RNA-Based Transcription Networks. ACS Synth Biol 2022; 11:1240-1250. [PMID: 35244392 DOI: 10.1021/acssynbio.1c00540] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The lack of signaling modularity of biomolecular systems poses major challenges toward engineering complex networks. Directional signaling between an upstream and a downstream circuit requires the presence of binding events, which result in the consumption of regulatory molecules and can compromise the operation of the upstream circuit. This issue has been previously addressed by introducing insulation strategies that include high-gain negative feedback and activation-deactivation reaction cycles. In this paper, we focus on RNA-based circuits and propose a new positive-feedback strategy to mitigate signal consumption that we propose occurs for each regulatory event due to irreversible binding of the RNA input to the RNA target. To mitigate this, an extra RNA input is added in tandem with transcription output to compensate the RNA consumption, leading to concentration robustness of the input RNA molecule regardless of the amount of downstream modules. We term this strategy RNA compensation, and it can be applied to systems that have a stringent input-output gain, such as Small Transcription Activating RNAs (STARs). Our theoretical analysis shows that RNA compensation not only eliminates the signaling consumption in individual STAR-based regulators, but also improves the composability of STAR cascades and the modularity of RNA bistable systems.
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Affiliation(s)
- Baiyang Liu
- Graduate Program in Systems, Synthetic, and Physical Biology, Rice University, Houston, Texas 77005, United States
| | - Christian Cuba Samaniego
- Department of Mechanical and Aerospace Engineering, Bioengineering, and Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
| | - Matthew Bennett
- Department of Biosciences, Rice University, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - James Chappell
- Department of Biosciences, Rice University, Houston, Texas 77005, United States
- Department of Bioengineering, Rice University, Houston, Texas 77005, United States
| | - Elisa Franco
- Department of Mechanical and Aerospace Engineering, Bioengineering, and Molecular Biology Institute, University of California at Los Angeles, Los Angeles, California 90095, United States
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16
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Climent-Catala A, Ouldridge TE, Stan GBV, Bae W. Building an RNA-Based Toggle Switch Using Inhibitory RNA Aptamers. ACS Synth Biol 2022; 11:562-569. [PMID: 35133150 PMCID: PMC9007568 DOI: 10.1021/acssynbio.1c00580] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Synthetic
RNA systems offer unique advantages such as faster response,
increased specificity, and programmability compared to conventional
protein-based networks. Here, we demonstrate an in vitro RNA-based toggle switch using RNA aptamers capable of inhibiting
the transcriptional activity of T7 or SP6 RNA polymerases. The activities
of both polymerases are monitored simultaneously by using Broccoli
and malachite green light-up aptamer systems. In our toggle switch,
a T7 promoter drives the expression of SP6 inhibitory aptamers, and
an SP6 promoter expresses T7 inhibitory aptamers. We show that the
two distinct states originating from the mutual inhibition of aptamers
can be toggled by adding DNA sequences to sequester the RNA inhibitory
aptamers. Finally, we assessed our RNA-based toggle switch in degrading
conditions by introducing controlled degradation of RNAs using a mix
of RNases. Our results demonstrate that the RNA-based toggle switch
could be used as a control element for nucleic acid networks in synthetic
biology applications.
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Affiliation(s)
- Alicia Climent-Catala
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Chemistry, Imperial College London, London, SW7 2AZ, U.K
| | - Thomas E. Ouldridge
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, U.K
| | - Guy-Bart V. Stan
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, U.K
| | - Wooli Bae
- Imperial College Centre for Synthetic Biology, London, SW7 2AZ, U.K
- Department of Bioengineering, Imperial College London, London, SW7 2AZ, U.K
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17
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Romantseva EF, Tack DS, Alperovich N, Ross D, Strychalski EA. Best Practices for DNA Template Preparation Toward Improved Reproducibility in Cell-Free Protein Production. Methods Mol Biol 2022; 2433:3-50. [PMID: 34985735 DOI: 10.1007/978-1-0716-1998-8_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Performance variability is a common challenge in cell-free protein production and hinders a wider adoption of these systems for both research and biomanufacturing. While the inherent stochasticity and complexity of biology likely contributes to variability, other systematic factors may also play a role, including the source and preparation of the cell extract, the composition of the supplemental reaction buffer, the facility at which experiments are conducted, and the human operator (Cole et al. ACS Synth Biol 8:2080-2091, 2019). Variability in protein production could also arise from differences in the DNA template-specifically the amount of functional DNA added to a cell-free reaction and the quality of the DNA preparation in terms of contaminants and strand breakage. Here, we present protocols and suggest best practices optimized for DNA template preparation and quantitation for cell-free systems toward reducing variability in cell-free protein production.
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Affiliation(s)
| | - Drew S Tack
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Nina Alperovich
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - David Ross
- National Institute of Standards and Technology, Gaithersburg, MD, USA
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18
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Anderson DA, Voigt CA. Competitive dCas9 binding as a mechanism for transcriptional control. Mol Syst Biol 2021; 17:e10512. [PMID: 34747560 PMCID: PMC8574044 DOI: 10.15252/msb.202110512] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 12/24/2022] Open
Abstract
Catalytically dead Cas9 (dCas9) is a programmable transcription factor that can be targeted to promoters through the design of small guide RNAs (sgRNAs), where it can function as an activator or repressor. Natural promoters use overlapping binding sites as a mechanism for signal integration, where the binding of one can block, displace, or augment the activity of the other. Here, we implemented this strategy in Escherichia coli using pairs of sgRNAs designed to repress and then derepress transcription through competitive binding. When designed to target a promoter, this led to 27-fold repression and complete derepression. This system was also capable of ratiometric input comparison over two orders of magnitude. Additionally, we used this mechanism for promoter sequence-independent control by adopting it for elongation control, achieving 8-fold repression and 4-fold derepression. This work demonstrates a new genetic control mechanism that could be used to build analog circuit or implement cis-regulatory logic on CRISPRi-targeted native genes.
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Affiliation(s)
- Daniel A Anderson
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Christopher A Voigt
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
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19
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20
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Tabuchi T, Yokobayashi Y. Cell-free riboswitches. RSC Chem Biol 2021; 2:1430-1440. [PMID: 34704047 PMCID: PMC8496063 DOI: 10.1039/d1cb00138h] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 07/26/2021] [Indexed: 12/16/2022] Open
Abstract
The emerging community of cell-free synthetic biology aspires to build complex biochemical and genetic systems with functions that mimic or even exceed those in living cells. To achieve such functions, cell-free systems must be able to sense and respond to the complex chemical signals within and outside the system. Cell-free riboswitches can detect chemical signals via RNA-ligand interaction and respond by regulating protein synthesis in cell-free protein synthesis systems. In this article, we review synthetic cell-free riboswitches that function in both prokaryotic and eukaryotic cell-free systems reported to date to provide a current perspective on the state of cell-free riboswitch technologies and their limitations.
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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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21
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Falgenhauer E, von Schönberg S, Meng C, Mückl A, Vogele K, Emslander Q, Ludwig C, Simmel FC. Evaluation of an E. coli Cell Extract Prepared by Lysozyme-Assisted Sonication via Gene Expression, Phage Assembly and Proteomics. Chembiochem 2021; 22:2805-2813. [PMID: 34240805 PMCID: PMC8518995 DOI: 10.1002/cbic.202100257] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/08/2021] [Indexed: 11/08/2022]
Abstract
Over the past decades, starting from crude cell extracts, a variety of successful preparation protocols and optimized reaction conditions have been established for the production of cell-free gene expression systems. One of the crucial steps during the preparation of cell extract-based expression systems is the cell lysis procedure itself, which largely determines the quality of the active components of the extract. Here we evaluate the utility of an E. coli cell extract, which was prepared using a combination of lysozyme incubation and a gentle sonication step. As quality measure, we demonstrate the cell-free expression of YFP at concentrations up to 0.6 mg/mL. In addition, we produced and assembled T7 bacteriophages up to a titer of 108 PFU/mL. State-of-the-art quantitative proteomics was used to compare the produced extracts with each other and with a commercial extract. The differences in protein composition were surprisingly small between lysozyme-assisted sonication (LAS) extracts, but we observed an increase in the release of DNA-binding proteins for increasing numbers of sonication cycles. Proteins taking part in carbohydrate metabolism, glycolysis, amino acid and nucleotide related pathways were found to be more abundant in the LAS extract, while proteins related to RNA modification and processing, DNA modification and replication, transcription regulation, initiation, termination and the TCA cycle were found enriched in the commercial extract.
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Affiliation(s)
- Elisabeth Falgenhauer
- Physics of Synthetic Biological Systems, Physics Department E14Technical University of MunichAm Coulombwall 4a85748GarchingGermany
| | - Sophie von Schönberg
- Physics of Synthetic Biological Systems, Physics Department E14Technical University of MunichAm Coulombwall 4a85748GarchingGermany
| | - Chen Meng
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS)Technical University of MunichGregor-Mendel-Strasse 485354FreisingGermany
| | - Andrea Mückl
- Physics of Synthetic Biological Systems, Physics Department E14Technical University of MunichAm Coulombwall 4a85748GarchingGermany
| | - Kilian Vogele
- Physics of Synthetic Biological Systems, Physics Department E14Technical University of MunichAm Coulombwall 4a85748GarchingGermany
| | - Quirin Emslander
- Physics of Synthetic Biological Systems, Physics Department E14Technical University of MunichAm Coulombwall 4a85748GarchingGermany
| | - Christina Ludwig
- Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS)Technical University of MunichGregor-Mendel-Strasse 485354FreisingGermany
| | - Friedrich C. Simmel
- Physics of Synthetic Biological Systems, Physics Department E14Technical University of MunichAm Coulombwall 4a85748GarchingGermany
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22
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Dudley QM, Cai YM, Kallam K, Debreyne H, Carrasco Lopez JA, Patron NJ. Biofoundry-assisted expression and characterization of plant proteins. Synth Biol (Oxf) 2021; 6:ysab029. [PMID: 34693026 PMCID: PMC8529701 DOI: 10.1093/synbio/ysab029] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 08/25/2021] [Accepted: 09/09/2021] [Indexed: 12/29/2022] Open
Abstract
Many goals in synthetic biology, including the elucidation and refactoring of biosynthetic pathways and the engineering of regulatory circuits and networks, require knowledge of protein function. In plants, the prevalence of large gene families means it can be particularly challenging to link specific functions to individual proteins. However, protein characterization has remained a technical bottleneck, often requiring significant effort to optimize expression and purification protocols. To leverage the ability of biofoundries to accelerate design-built-test-learn cycles, we present a workflow for automated DNA assembly and cell-free expression of plant proteins that accelerates optimization and enables rapid screening of enzyme activity. First, we developed a phytobrick-compatible Golden Gate DNA assembly toolbox containing plasmid acceptors for cell-free expression using Escherichia coli or wheat germ lysates as well as a set of N- and C-terminal tag parts for detection, purification and improved expression/folding. We next optimized automated assembly of miniaturized cell-free reactions using an acoustic liquid handling platform and then compared tag configurations to identify those that increase expression. We additionally developed a luciferase-based system for rapid quantification that requires a minimal 11-amino acid tag and demonstrate facile removal of tags following synthesis. Finally, we show that several functional assays can be performed with cell-free protein synthesis reactions without the need for protein purification. Together, the combination of automated assembly of DNA parts and cell-free expression reactions should significantly increase the throughput of experiments to test and understand plant protein function and enable the direct reuse of DNA parts in downstream plant engineering workflows.
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Affiliation(s)
- Quentin M Dudley
- Engineering Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk UK
| | - Yao-Min Cai
- Engineering Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk UK
| | - Kalyani Kallam
- Engineering Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk UK
| | - Hubert Debreyne
- Engineering Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk UK
| | | | - Nicola J Patron
- Engineering Biology, Earlham Institute, Norwich Research Park, Norwich, Norfolk UK
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23
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Arce A, Guzman Chavez F, Gandini C, Puig J, Matute T, Haseloff J, Dalchau N, Molloy J, Pardee K, Federici F. Decentralizing Cell-Free RNA Sensing With the Use of Low-Cost Cell Extracts. Front Bioeng Biotechnol 2021; 9:727584. [PMID: 34497801 PMCID: PMC8419261 DOI: 10.3389/fbioe.2021.727584] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/06/2021] [Indexed: 11/13/2022] Open
Abstract
Cell-free gene expression systems have emerged as a promising platform for field-deployed biosensing and diagnostics. When combined with programmable toehold switch-based RNA sensors, these systems can be used to detect arbitrary RNAs and freeze-dried for room temperature transport to the point-of-need. These sensors, however, have been mainly implemented using reconstituted PURE cell-free protein expression systems that are difficult to source in the Global South due to their high commercial cost and cold-chain shipping requirements. Based on preliminary demonstrations of toehold sensors working on lysates, we describe the fast prototyping of RNA toehold switch-based sensors that can be produced locally and reduce the cost of sensors by two orders of magnitude. We demonstrate that these in-house cell lysates provide sensor performance comparable to commercial PURE cell-free systems. We further optimize these lysates with a CRISPRi strategy to enhance the stability of linear DNAs by knocking-down genes responsible for linear DNA degradation. This enables the direct use of PCR products for fast screening of new designs. As a proof-of-concept, we develop novel toehold sensors for the plant pathogen Potato Virus Y (PVY), which dramatically reduces the yield of this important staple crop. The local implementation of low-cost cell-free toehold sensors could enable biosensing capacity at the regional level and lead to more decentralized models for global surveillance of infectious disease.
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Affiliation(s)
- Anibal Arce
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Chiara Gandini
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Juan Puig
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Tamara Matute
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Jim Haseloff
- Department of Plant Sciences, University of Cambridge, Cambridge, United Kingdom
| | | | - Jenny Molloy
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, United Kingdom
| | - Keith Pardee
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - Fernán Federici
- ANID – Millennium Science Initiative Program – Millennium Institute for Integrative Biology (iBio), Santiago, Chile
- Schools of Engineering, Institute for Biological and Medical Engineering, Medicine and Biological Sciences, Pontificia Universidad Católica de Chile, Santiago, Chile
- Departamento de Genética Molecular y Microbiología, Pontificia Universidad Católica de Chile, Santiago, Chile
- FONDAP Center for Genome Regulation, Santiago, Chile
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24
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Garenne D, Thompson S, Brisson A, Khakimzhan A, Noireaux V. The all-E. coliTXTL toolbox 3.0: new capabilities of a cell-free synthetic biology platform. Synth Biol (Oxf) 2021; 6:ysab017. [PMID: 34712841 PMCID: PMC8546610 DOI: 10.1093/synbio/ysab017] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/19/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022] Open
Abstract
The new generation of cell-free gene expression systems enables the prototyping and engineering of biological systems in vitro over a remarkable scope of applications and physical scales. As the utilization of DNA-directed in vitro protein synthesis expands in scope, developing more powerful cell-free transcription-translation (TXTL) platforms remains a major goal to either execute larger DNA programs or improve cell-free biomanufacturing capabilities. In this work, we report the capabilities of the all-E. coli TXTL toolbox 3.0, a multipurpose cell-free expression system specifically developed for synthetic biology. In non-fed batch-mode reactions, the synthesis of the fluorescent reporter protein eGFP (enhanced green fluorescent protein) reaches 4 mg/ml. In synthetic cells, consisting of liposomes loaded with a TXTL reaction, eGFP is produced at concentrations of >8 mg/ml when the chemical building blocks feeding the reaction diffuse through membrane channels to facilitate exchanges with the outer solution. The bacteriophage T7, encoded by a genome of 40 kb and ∼60 genes, is produced at a concentration of 1013 PFU/ml (plaque forming unit/ml). This TXTL system extends the current cell-free expression capabilities by offering unique strength and properties, for testing regulatory elements and circuits, biomanufacturing biologics or building synthetic cells.
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Affiliation(s)
- David Garenne
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Seth Thompson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Amaury Brisson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Aset Khakimzhan
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
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25
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Hou S, Zhang J, Ma X, Hong Q, Fang L, Zheng G, Huang J, Gao Y, Xu Q, Zhuang X, Song X. Role of rgsA in Oxidative Stress Resistance in Pseudomonas aeruginosa. Curr Microbiol 2021; 78:3133-3141. [PMID: 34185129 DOI: 10.1007/s00284-021-02580-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 06/13/2021] [Indexed: 10/21/2022]
Abstract
Pseudomonas aeruginosa is a common opportunistic pathogen that causes infections in vulnerable patients including those with metabolic disorders, hematologic diseases, and malignancies, and in those who have undergone surgery. In addition, P. aeruginosa exhibits high intrinsic resistance to numerous antibiotics and tends to form biofilms rendering it even more refractory to treatment. Among the mechanisms used by P. aeruginosa to adapt to environmental stresses are those involving small regulatory RNAs (sRNAs), which are 40-500 nucleotides long and are ubiquitous in bacteria. sRNAs play important regulatory roles in various vital processes in diverse bacteria, with their quantity and diversity of regulatory functions exceeding those of proteins. In this study, we show that deletion of the sRNA, rgsA, decreased the growth rate of P. aeruginosa. Furthermore, ΔrgsA P. aeruginosa exhibited decreased ability to resist the stress induced by exposure to different concentrations and durations of peroxides in both planktonic and biofilm growth modes compared with the wild-type strain. These results highlight the role of rgsA in the defense of P. aeruginosa against oxidative stress.
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Affiliation(s)
- Shuyi Hou
- Department of Clinical Laboratory, Xiang'an Hospital of Xiamen University, 2000 Xiangan Dong Road, Xiamen, 361000, Fujian, China
| | - Jiaqin Zhang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, 55 Zhenhai Road, Xiamen, 361000, Fujian, China. .,Xiamen Key Laboratory of Genetic Testing, 55 Zhenhai Road, Xiamen, 361000, Fujian, China.
| | - Xiaobo Ma
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, 55 Zhenhai Road, Xiamen, 361000, Fujian, China
| | - Qiang Hong
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, 55 Zhenhai Road, Xiamen, 361000, Fujian, China
| | - Lili Fang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, 55 Zhenhai Road, Xiamen, 361000, Fujian, China
| | - Gangsen Zheng
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, 55 Zhenhai Road, Xiamen, 361000, Fujian, China
| | - Jiaming Huang
- Department of Clinical Laboratory, The Second Affiliated Hospital of Fujian Medical University, 34 Zhongshan North Road, Quanzhou, 362000, Fujian, China
| | - Yingchun Gao
- Department of Clinical Laboratory, The First People's Hospital of Xiaoshan District, 199 Shixin Nan Road, Hangzhou, 311200, Zhejiang, China
| | - Qiaoli Xu
- Department of Clinical Laboratory, Zhangzhou Affiliated Hospital of Fujian Medical University, 59 Shengli Road, Zhangzhou, 363000, Fujian, China
| | - Xinguo Zhuang
- Department of Clinical Laboratory, The First Affiliated Hospital of Xiamen University, 55 Zhenhai Road, Xiamen, 361000, Fujian, China
| | - Xiuyu Song
- Xiamen Blood Centre, 121 Hubin Nan Road, Xiamen, 361000, Fujian, China.
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26
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Kim J, Quijano JF, Kim J, Yeung E, Murray RM. Synthetic logic circuits using RNA aptamer against T7 RNA polymerase. Biotechnol J 2021; 17:e2000449. [PMID: 33813787 DOI: 10.1002/biot.202000449] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 03/05/2021] [Accepted: 03/30/2021] [Indexed: 12/23/2022]
Abstract
Recent advances in nucleic acids engineering introduced several RNA-based regulatory components for synthetic gene circuits, expanding the toolsets to engineer organisms. In this work, we designed genetic circuits implementing an RNA aptamer previously described to have the capability of binding to the T7 RNA polymerase and inhibiting its activity in vitro. We first demonstrated the utility of the RNA aptamer in combination with programmable synthetic transcription networks in vitro. As a step to quickly assess the feasibility of aptamer functions in vivo, we tested the aptamer and its sequence variants in the cell-free expression system, verifying the aptamer functionality in the cell-free testbed. The expression of aptamer in E. coli demonstrated control over GFP expression driven by T7 RNA polymerase, indicating its ability to serve as building blocks for logic circuits and transcriptional cascades. This work elucidates the potential of T7 RNA polymerase aptamer as regulators for synthetic biological circuits and metabolic engineering.
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Affiliation(s)
- Jongmin Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea.,Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA
| | - Juan F Quijano
- Department of Biological Sciences, Columbia University, New York, New York, USA
| | - Jeongwon Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Enoch Yeung
- Department of Control and Dynamical Systems, California Institute of Technology, Pasadena, California, USA.,Department of Mechanical Engineering, University of California, Santa Barbara, California, USA
| | - Richard M Murray
- Department of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, USA.,Department of Control and Dynamical Systems, California Institute of Technology, Pasadena, California, USA
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27
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Swank Z, Maerkl SJ. CFPU: A Cell-Free Processing Unit for High-Throughput, Automated In Vitro Circuit Characterization in Steady-State Conditions. BIODESIGN RESEARCH 2021; 2021:2968181. [PMID: 37849954 PMCID: PMC10521719 DOI: 10.34133/2021/2968181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 02/24/2021] [Indexed: 10/19/2023] Open
Abstract
Forward engineering synthetic circuits are at the core of synthetic biology. Automated solutions will be required to facilitate circuit design and implementation. Circuit design is increasingly being automated with design software, but innovations in experimental automation are lagging behind. Microfluidic technologies made it possible to perform in vitro transcription-translation (tx-tl) reactions with increasing throughput and sophistication, enabling screening and characterization of individual circuit elements and complete circuit designs. Here, we developed an automated microfluidic cell-free processing unit (CFPU) that extends high-throughput screening capabilities to a steady-state reaction environment, which is essential for the implementation and analysis of more complex and dynamic circuits. The CFPU contains 280 chemostats that can be individually programmed with DNA circuits. Each chemostat is periodically supplied with tx-tl reagents, giving rise to sustained, long-term steady-state conditions. Using microfluidic pulse width modulation (PWM), the device is able to generate tx-tl reagent compositions in real time. The device has higher throughput, lower reagent consumption, and overall higher functionality than current chemostat devices. We applied this technology to map transcription factor-based repression under equilibrium conditions and implemented dynamic gene circuits switchable by small molecules. We expect the CFPU to help bridge the gap between circuit design and experimental automation for in vitro development of synthetic gene circuits.
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Affiliation(s)
- Zoe Swank
- Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
| | - Sebastian J. Maerkl
- Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne, Switzerland
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28
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Moore SJ, Lai HE, Chee SM, Toh M, Coode S, Chengan K, Capel P, Corre C, de los Santos ELC, Freemont PS. A Streptomyces venezuelae Cell-Free Toolkit for Synthetic Biology. ACS Synth Biol 2021; 10:402-411. [PMID: 33497199 PMCID: PMC7901020 DOI: 10.1021/acssynbio.0c00581] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
Prokaryotic
cell-free coupled transcription–translation
(TX-TL) systems are emerging as a powerful tool to examine natural
product biosynthetic pathways in a test tube. The key advantages of
this approach are the reduced experimental time scales and controlled
reaction conditions. To realize this potential, it is essential to
develop specialized cell-free systems in organisms enriched for biosynthetic
gene clusters. This requires strong protein production and well-characterized
synthetic biology tools. The Streptomyces genus is
a major source of natural products. To study enzymes and pathways
from Streptomyces, we originally developed a homologous Streptomyces cell-free system to provide a native protein
folding environment, a high G+C (%) tRNA pool, and an active background
metabolism. However, our initial yields were low (36 μg/mL)
and showed a high level of batch-to-batch variation. Here, we present
an updated high-yield and robust Streptomyces TX-TL
protocol, reaching up to yields of 266 μg/mL of expressed recombinant
protein. To complement this, we rapidly characterize a range of DNA
parts with different reporters, express high G+C (%) biosynthetic
genes, and demonstrate an initial proof of concept for combined transcription,
translation, and biosynthesis of Streptomyces metabolic
pathways in a single “one-pot” reaction.
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Affiliation(s)
- Simon J. Moore
- Centre for Synthetic Biology and Innovation, Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- Department Section of Structural and Synthetic Biology, Department of Infectious Disease; Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, U.K
| | - Hung-En Lai
- Centre for Synthetic Biology and Innovation, Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- Department Section of Structural and Synthetic Biology, Department of Infectious Disease; Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
| | - Soo-Mei Chee
- Department Section of Structural and Synthetic Biology, Department of Infectious Disease; Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- The London Biofoundry, Imperial College Translation & Innovation Hub, White City Campus, 80 Wood Lane, London W12 0BZ, U.K
| | - Ming Toh
- Centre for Synthetic Biology and Innovation, Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- Department Section of Structural and Synthetic Biology, Department of Infectious Disease; Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
| | - Seth Coode
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, U.K
| | - Kameshwari Chengan
- School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, U.K
| | - Patrick Capel
- Warwick Integrative Synthetic Biology Centre, School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, U.K
| | - Christophe Corre
- Warwick Integrative Synthetic Biology Centre, School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, U.K
| | - Emmanuel LC de los Santos
- Warwick Integrative Synthetic Biology Centre, School of Life Sciences, University of Warwick, Gibbet Hill Road, Coventry, CV4 7AL, U.K
| | - Paul S. Freemont
- Centre for Synthetic Biology and Innovation, Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- Department Section of Structural and Synthetic Biology, Department of Infectious Disease; Imperial College London, South Kensington Campus, Exhibition Road, London, SW7 2AZ, U.K
- The London Biofoundry, Imperial College Translation & Innovation Hub, White City Campus, 80 Wood Lane, London W12 0BZ, U.K
- UK Dementia Research Institute Care Research and Technology Centre, Imperial College London, Hammersmith Campus, Du Cane Road, London, W12 0N, U.K
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29
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Singhal V, Tuza ZA, Sun ZZ, Murray RM. A MATLAB toolbox for modeling genetic circuits in cell-free systems. Synth Biol (Oxf) 2021; 6:ysab007. [PMID: 33981862 PMCID: PMC8102020 DOI: 10.1093/synbio/ysab007] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/07/2020] [Accepted: 12/23/2020] [Indexed: 01/19/2023] Open
Abstract
We introduce a MATLAB-based simulation toolbox, called txtlsim, for an Escherichia coli-based Transcription-Translation (TX-TL) system. This toolbox accounts for several cell-free-related phenomena, such as resource loading, consumption and degradation, and in doing so, models the dynamics of TX-TL reactions for the entire duration of solution phase batch-mode experiments. We use a Bayesian parameter inference approach to characterize the reaction rate parameters associated with the core transcription, translation and mRNA degradation mechanics of the toolbox, allowing it to reproduce constitutive mRNA and protein-expression trajectories. We demonstrate the use of this characterized toolbox in a circuit behavior prediction case study for an incoherent feed-forward loop.
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Affiliation(s)
- Vipul Singhal
- Spatial and Single Cell Systems Domain, Genome Institute of Singapore, 60 Biopolis St, 138672, Singapore
| | - Zoltan A Tuza
- Department of Bioengineering, Imperial College London, Exhibition Rd, South Kensington, SW7 2BU, London, UK
| | - Zachary Z Sun
- Tierra Bioscienes, 1933 Davis St #223, 94577, CA, USA
| | - Richard M Murray
- Control and Dynamical Systems and Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd, 91125, CA, USA
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30
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Yang J, Lu Y. Physical stimuli-responsive cell-free protein synthesis. Synth Syst Biotechnol 2020; 5:363-368. [PMID: 33294650 PMCID: PMC7695910 DOI: 10.1016/j.synbio.2020.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/11/2020] [Accepted: 11/12/2020] [Indexed: 11/18/2022] Open
Abstract
Cell-free protein synthesis has been developed as a critical platform in synthetic biology. Unlike the cell-based synthesis system, cell-free system activates transcriptional and translational mechanisms in vitro, and can control protein synthesis by artificially adding components or chemicals. However, the control method puts forward higher requirements in terms of accurate and non-toxic control, which cannot be achieved by chemical substances. For cell-free system, physical signal is a kind of ideal spatiotemporal control approach to replace chemical substances, realizing high accuracy with little side effect. Here we review the methods of using physical signals to control gene expression in cell-free systems, including studies based on light, temperature, electric field, and magnetic force. The transfer of these switches into cell-free system further expands the flexibility and controllability of the system, thus further expanding the application capability of cell-free systems. Finally, existing problems such as signal source and signal transmission are discussed, and future applications in pharmaceutical production, delivery and industrial production are further looked into.
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Affiliation(s)
- Junzhu Yang
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
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31
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Müller J, Siemann-Herzberg M, Takors R. Modeling Cell-Free Protein Synthesis Systems-Approaches and Applications. Front Bioeng Biotechnol 2020; 8:584178. [PMID: 33195146 PMCID: PMC7655533 DOI: 10.3389/fbioe.2020.584178] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/29/2020] [Indexed: 01/03/2023] Open
Abstract
In vitro systems are ideal setups to investigate the basic principles of biochemical reactions and subsequently the bricks of life. Cell-free protein synthesis (CFPS) systems mimic the transcription and translation processes of whole cells in a controlled environment and allow the detailed study of single components and reaction networks. In silico studies of CFPS systems help us to understand interactions and to identify limitations and bottlenecks in those systems. Black-box models laid the foundation for understanding the production and degradation dynamics of macromolecule components such as mRNA, ribosomes, and proteins. Subsequently, more sophisticated models revealed shortages in steps such as translation initiation and tRNA supply and helped to partially overcome these limitations. Currently, the scope of CFPS modeling has broadened to various applications, ranging from the screening of kinetic parameters to the stochastic analysis of liposome-encapsulated CFPS systems and the assessment of energy supply properties in combination with flux balance analysis (FBA).
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Affiliation(s)
| | | | - Ralf Takors
- Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany
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32
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Abstract
Cell-free systems, as part of the synthetic biology field, have become a critical platform in biological studies. However, there is a lack of research into developing a switch for a dynamical control of the transcriptional and translational process. The optogenetic tool has been widely proven as an ideal control switch for protein synthesis due to its nontoxicity and excellent time-space conversion. Hence, in this study, a blue light-regulated two-component system named YF1/FixJ was incorporated into an Escherichia coli-based cell-free system to control protein synthesis. The corresponding cell-free system successfully achieved a 5-fold dynamic protein expression by blue light repression and 3-fold dynamic expression by blue light activation. With the aim of expanding the applications of cell-free synthetic biology, the cell-free blue light-sensing system was used to perform imaging, light-controlled antibody synthesis, and light-triggered artificial cell assembly. This study can provide a guide for further research into the field of cell-free optical sensing. Moreover, it will also promote the development of cell-free synthetic biology and optogenetics through applying the cell-free optical sensing system to synthetic biology education, biopharmaceutical research, and artificial cell construction.
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Affiliation(s)
- Peng Zhang
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Junzhu Yang
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Eunhee Cho
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
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33
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Marucci L, Barberis M, Karr J, Ray O, Race PR, de Souza Andrade M, Grierson C, Hoffmann SA, Landon S, Rech E, Rees-Garbutt J, Seabrook R, Shaw W, Woods C. Computer-Aided Whole-Cell Design: Taking a Holistic Approach by Integrating Synthetic With Systems Biology. Front Bioeng Biotechnol 2020; 8:942. [PMID: 32850764 PMCID: PMC7426639 DOI: 10.3389/fbioe.2020.00942] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 07/21/2020] [Indexed: 01/03/2023] Open
Abstract
Computer-aided design (CAD) for synthetic biology promises to accelerate the rational and robust engineering of biological systems. It requires both detailed and quantitative mathematical and experimental models of the processes to (re)design biology, and software and tools for genetic engineering and DNA assembly. Ultimately, the increased precision in the design phase will have a dramatic impact on the production of designer cells and organisms with bespoke functions and increased modularity. CAD strategies require quantitative models of cells that can capture multiscale processes and link genotypes to phenotypes. Here, we present a perspective on how whole-cell, multiscale models could transform design-build-test-learn cycles in synthetic biology. We show how these models could significantly aid in the design and learn phases while reducing experimental testing by presenting case studies spanning from genome minimization to cell-free systems. We also discuss several challenges for the realization of our vision. The possibility to describe and build whole-cells in silico offers an opportunity to develop increasingly automatized, precise and accessible CAD tools and strategies.
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Affiliation(s)
- Lucia Marucci
- Department of Engineering Mathematics, University of Bristol, Bristol, United Kingdom.,School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom.,Bristol Centre for Synthetic Biology (BrisSynBio), University of Bristol, Bristol, United Kingdom
| | - Matteo Barberis
- Systems Biology, School of Biosciences and Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Centre for Mathematical and Computational Biology, CMCB, University of Surrey, Guildford, United Kingdom.,Synthetic Systems Biology and Nuclear Organization, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
| | - Jonathan Karr
- Icahn Institute for Data Science and Genomic Technology, Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Oliver Ray
- Department of Computer Science, University of Bristol, Bristol, United Kingdom
| | - Paul R Race
- Bristol Centre for Synthetic Biology (BrisSynBio), University of Bristol, Bristol, United Kingdom.,School of Biochemistry, University of Bristol, Bristol, United Kingdom
| | - Miguel de Souza Andrade
- Brazilian Agricultural Research Corporation/National Institute of Science and Technology - Synthetic Biology, Brasília, Brazil.,Department of Cell Biology, Institute of Biological Sciences, University of Brasília, Brasília, Brazil
| | - Claire Grierson
- Bristol Centre for Synthetic Biology (BrisSynBio), University of Bristol, Bristol, United Kingdom.,School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Stefan Andreas Hoffmann
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
| | - Sophie Landon
- Department of Engineering Mathematics, University of Bristol, Bristol, United Kingdom.,Bristol Centre for Synthetic Biology (BrisSynBio), University of Bristol, Bristol, United Kingdom
| | - Elibio Rech
- Brazilian Agricultural Research Corporation/National Institute of Science and Technology - Synthetic Biology, Brasília, Brazil
| | - Joshua Rees-Garbutt
- Bristol Centre for Synthetic Biology (BrisSynBio), University of Bristol, Bristol, United Kingdom.,School of Biological Sciences, University of Bristol, Bristol, United Kingdom
| | - Richard Seabrook
- Elizabeth Blackwell Institute for Health Research (EBI), University of Bristol, Bristol, United Kingdom
| | - William Shaw
- Department of Bioengineering, Imperial College London, London, United Kingdom
| | - Christopher Woods
- Bristol Centre for Synthetic Biology (BrisSynBio), University of Bristol, Bristol, United Kingdom.,School of Chemistry, University of Bristol, Bristol, United Kingdom
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34
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Khatri Y, Hohlman RM, Mendoza J, Li S, Lowell AN, Asahara H, Sherman DH. Multicomponent Microscale Biosynthesis of Unnatural Cyanobacterial Indole Alkaloids. ACS Synth Biol 2020; 9:1349-1360. [PMID: 32302487 PMCID: PMC7323787 DOI: 10.1021/acssynbio.0c00038] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Genome sequencing and bioinformatics tools have facilitated the identification and expression of an increasing number of cryptic biosynthetic gene clusters (BGCs). However, functional analysis of all components of a metabolic pathway to precisely determine biocatalytic properties remains time-consuming and labor intensive. One way to speed this process involves microscale cell-free protein synthesis (CFPS) for direct gene to biochemical function analysis, which has rarely been applied to study multicomponent enzymatic systems in specialized metabolism. We sought to establish an in vitro transcription/translation (TT)-assay to assess assembly of cyanobacterial-derived hapalindole-type natural products (cNPs) because of their diverse bioactivity profiles and complex structural diversity. Using a CFPS system including a plasmid bearing famD2 prenyltransferase from Fischerella ambigua UTEX 1903, we showed production of the central prenylated intermediate (3GC) in the presence of exogenous geranyl-pyrophosphate (GPP) and cis-indole isonitrile. Further addition of a plasmid bearing the famC1 Stig cyclase resulted in synthesis of both FamD2 and FamC1 enzymes, which was confirmed by proteomics analysis, and catalyzed assembly of 12-epi-hapalindole U. Further combinations of Stig cyclases (FamC1-C4) produced hapalindole U and hapalindole H, while FisC identified from Fischerella sp. SAG46.79 generated 12-epi-fischerindole U. The CFPS system was further employed to screen six unnatural halogenated cis-indole isonitrile substrates using FamC1 and FisC, and the reactions were scaled-up using chemoenzymatic synthesis and identified as 5- and 6-fluoro-12-epi-hapalindole U, and 5- and 6-fluoro-12-epi-fischerindole U, respectively. This approach represents an effective, high throughput strategy to determine the functional role of biosynthetic enzymes from diverse natural product BGCs.
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Affiliation(s)
| | | | | | | | | | - Haruichi Asahara
- New England Biolabs, Inc., Ipswich, Massachusetts 01938, United States
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35
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Development of a clostridia-based cell-free system for prototyping genetic parts and metabolic pathways. Metab Eng 2020; 62:95-105. [PMID: 32540392 DOI: 10.1016/j.ymben.2020.06.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/15/2020] [Accepted: 06/07/2020] [Indexed: 02/04/2023]
Abstract
Gas fermentation by autotrophic bacteria, such as clostridia, offers a sustainable path to numerous bioproducts from a range of local, highly abundant, waste and low-cost feedstocks, such as industrial flue gases or syngas generated from biomass or municipal waste. Unfortunately, designing and engineering clostridia remains laborious and slow. The ability to prototype individual genetic part function, gene expression patterns, and biosynthetic pathway performance in vitro before implementing designs in cells could help address these bottlenecks by speeding up design. Unfortunately, a high-yielding cell-free gene expression (CFE) system from clostridia has yet to be developed. Here, we report the development and optimization of a high-yielding (236 ± 24 μg/mL) batch CFE platform from the industrially relevant anaerobe, Clostridium autoethanogenum. A key feature of the platform is that both circular and linear DNA templates can be applied directly to the CFE reaction to program protein synthesis. We demonstrate the ability to prototype gene expression, and quantitatively map aerobic cell-free metabolism in lysates from this system. We anticipate that the C. autoethanogenum CFE platform will not only expand the protein synthesis toolkit for synthetic biology, but also serve as a platform in expediting the screening and prototyping of gene regulatory elements in non-model, industrially relevant microbes.
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36
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Wrist A, Sun W, Summers RM. The Theophylline Aptamer: 25 Years as an Important Tool in Cellular Engineering Research. ACS Synth Biol 2020; 9:682-697. [PMID: 32142605 DOI: 10.1021/acssynbio.9b00475] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The theophylline aptamer was isolated from an oligonucleotide library in 1994. Since that time, the aptamer has found wide utility, particularly in synthetic biology, cellular engineering, and diagnostic applications. The primary application of the theophylline aptamer is in the construction and characterization of synthetic riboswitches for regulation of gene expression. These riboswitches have been used to control cellular motility, regulate carbon metabolism, construct logic gates, screen for mutant enzymes, and control apoptosis. Other applications of the theophylline aptamer in cellular engineering include regulation of RNA interference and genome editing through CRISPR systems. Here we describe the uses of the theophylline aptamer for cellular engineering over the past 25 years. In so doing, we also highlight important synthetic biology applications to control gene expression in a ligand-dependent manner.
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Affiliation(s)
- Alexandra Wrist
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Wanqi Sun
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Ryan M. Summers
- Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States
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37
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Laohakunakorn N, Grasemann L, Lavickova B, Michielin G, Shahein A, Swank Z, Maerkl SJ. Bottom-Up Construction of Complex Biomolecular Systems With Cell-Free Synthetic Biology. Front Bioeng Biotechnol 2020; 8:213. [PMID: 32266240 PMCID: PMC7105575 DOI: 10.3389/fbioe.2020.00213] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 03/03/2020] [Indexed: 12/16/2022] Open
Abstract
Cell-free systems offer a promising approach to engineer biology since their open nature allows for well-controlled and characterized reaction conditions. In this review, we discuss the history and recent developments in engineering recombinant and crude extract systems, as well as breakthroughs in enabling technologies, that have facilitated increased throughput, compartmentalization, and spatial control of cell-free protein synthesis reactions. Combined with a deeper understanding of the cell-free systems themselves, these advances improve our ability to address a range of scientific questions. By mastering control of the cell-free platform, we will be in a position to construct increasingly complex biomolecular systems, and approach natural biological complexity in a bottom-up manner.
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Affiliation(s)
- Nadanai Laohakunakorn
- School of Biological Sciences, Institute of Quantitative Biology, Biochemistry, and Biotechnology, University of Edinburgh, Edinburgh, United Kingdom
| | - Laura Grasemann
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Barbora Lavickova
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Grégoire Michielin
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Amir Shahein
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Zoe Swank
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Sebastian J. Maerkl
- School of Engineering, Institute of Bioengineering, École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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38
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Silverman AD, Akova U, Alam KK, Jewett MC, Lucks JB. Design and Optimization of a Cell-Free Atrazine Biosensor. ACS Synth Biol 2020; 9:671-677. [PMID: 32078765 DOI: 10.1021/acssynbio.9b00388] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Recent advances in cell-free synthetic biology have spurred the development of in vitro molecular diagnostics that serve as effective alternatives to whole-cell biosensors. However, cell-free sensors for detecting manmade organic water contaminants such as pesticides are sparse, partially because few characterized natural biological sensors can directly detect such pollutants. Here, we present a platform for the cell-free detection of one critical water contaminant, atrazine, by combining a previously characterized cyanuric acid biosensor with a reconstituted atrazine-to-cyanuric acid metabolic pathway composed of several protein-enriched bacterial extracts mixed in a one pot reaction. Our cell-free sensor detects atrazine within an hour of incubation at an activation ratio superior to previously reported whole-cell atrazine sensors. We also show that the response characteristics of the atrazine sensor can be tuned by manipulating the ratios of enriched extracts in the cell-free reaction mixture. Our approach of utilizing multiple metabolic steps, encoded in protein-enriched cell-free extracts, to convert a target of interest into a molecule that can be sensed by a transcription factor is modular. Our work thus serves as an effective proof-of-concept for a scheme of "metabolic biosensing", which should enable rapid, field-deployable detection of complex organic water contaminants.
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Affiliation(s)
| | | | | | - Michael C. Jewett
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
| | - Julius B. Lucks
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
- Center for Water Research, Northwestern University, Evanston, Illinois 60208, United States
- Center for Engineering Sustainability and Resilience, Northwestern University, Evanston, Illinois 60208, United States
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Silverman AD, Akova U, Alam KK, Jewett MC, Lucks JB. Design and Optimization of a Cell-Free Atrazine Biosensor. ACS Synth Biol 2020. [PMID: 32078765 DOI: 10.1101/779827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Recent advances in cell-free synthetic biology have spurred the development of in vitro molecular diagnostics that serve as effective alternatives to whole-cell biosensors. However, cell-free sensors for detecting manmade organic water contaminants such as pesticides are sparse, partially because few characterized natural biological sensors can directly detect such pollutants. Here, we present a platform for the cell-free detection of one critical water contaminant, atrazine, by combining a previously characterized cyanuric acid biosensor with a reconstituted atrazine-to-cyanuric acid metabolic pathway composed of several protein-enriched bacterial extracts mixed in a one pot reaction. Our cell-free sensor detects atrazine within an hour of incubation at an activation ratio superior to previously reported whole-cell atrazine sensors. We also show that the response characteristics of the atrazine sensor can be tuned by manipulating the ratios of enriched extracts in the cell-free reaction mixture. Our approach of utilizing multiple metabolic steps, encoded in protein-enriched cell-free extracts, to convert a target of interest into a molecule that can be sensed by a transcription factor is modular. Our work thus serves as an effective proof-of-concept for a scheme of "metabolic biosensing", which should enable rapid, field-deployable detection of complex organic water contaminants.
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Affiliation(s)
| | | | | | - Michael C Jewett
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
| | - Julius B Lucks
- Interdisciplinary Biological Sciences Program, Northwestern University, Evanston, Illinois 60208, United States
- Center for Water Research, Northwestern University, Evanston, Illinois 60208, United States
- Center for Engineering Sustainability and Resilience, Northwestern University, Evanston, Illinois 60208, United States
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40
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Voyvodic PL, Bonnet J. Cell-free biosensors for biomedical applications. CURRENT OPINION IN BIOMEDICAL ENGINEERING 2020. [DOI: 10.1016/j.cobme.2019.08.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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41
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Jia H, Schwille P. Bottom-up synthetic biology: reconstitution in space and time. Curr Opin Biotechnol 2019; 60:179-187. [DOI: 10.1016/j.copbio.2019.05.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 05/07/2019] [Indexed: 01/30/2023]
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Silverman AD, Karim AS, Jewett MC. Cell-free gene expression: an expanded repertoire of applications. Nat Rev Genet 2019; 21:151-170. [DOI: 10.1038/s41576-019-0186-3] [Citation(s) in RCA: 246] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2019] [Indexed: 12/24/2022]
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43
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Zhao VXT, Wong TI, Zheng XT, Tan YN, Zhou X. Colorimetric biosensors for point-of-care virus detections. MATERIALS SCIENCE FOR ENERGY TECHNOLOGIES 2019; 3:237-249. [PMID: 33604529 PMCID: PMC7148662 DOI: 10.1016/j.mset.2019.10.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 10/13/2019] [Accepted: 10/14/2019] [Indexed: 05/05/2023]
Abstract
Colorimetric biosensors can be used to detect a particular analyte through color changes easily by naked eyes or simple portable optical detectors for quantitative measurement. Thus, it is highly attractive for point-of-care detections of harmful viruses to prevent potential pandemic outbreak, as antiviral medication must be administered in a timely fashion. This review paper summaries existing and emerging techniques that can be employed to detect viruses through colorimetric assay design with detailed discussion of their sensing principles, performances as well as pros and cons, with an aim to provide guideline on the selection of suitable colorimetric biosensors for detecting different species of viruses. Among the colorimetric methods for virus detections, loop-mediated isothermal amplification (LAMP) method is more favourable for its faster detection, high efficiency, cheaper cost, and more reliable with high reproducible assay results. Nanoparticle-based colorimetric biosensors, on the other hand, are most suitable to be fabricated into lateral flow or lab-on-a-chip devices, and can be coupled with LAMP or portable PCR systems for highly sensitive on-site detection of viruses, which is very critical for early diagnosis of virus infections and to prevent outbreak in a swift and controlled manner.
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Affiliation(s)
- Victoria Xin Ting Zhao
- College of Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore
| | - Ten It Wong
- Institute of Materials Research and Engineering, ASTAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Singapore
| | - Xin Ting Zheng
- Institute of Materials Research and Engineering, ASTAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Singapore
| | - Yen Nee Tan
- Institute of Materials Research and Engineering, ASTAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Singapore
- Faculty of Science, Agriculture & Engineering, Newcastle University, Newcastle Upon Tyne NE1 7RU, United Kingdom
| | - Xiaodong Zhou
- Institute of Materials Research and Engineering, ASTAR (Agency for Science, Technology and Research), 2 Fusionopolis Way, #08-03, Innovis, Singapore 138634, Singapore
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44
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Khambhati K, Bhattacharjee G, Gohil N, Braddick D, Kulkarni V, Singh V. Exploring the Potential of Cell-Free Protein Synthesis for Extending the Abilities of Biological Systems. Front Bioeng Biotechnol 2019; 7:248. [PMID: 31681738 PMCID: PMC6797904 DOI: 10.3389/fbioe.2019.00248] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 09/16/2019] [Indexed: 12/19/2022] Open
Abstract
Cell-free protein synthesis (CFPS) system is a simple, rapid, and sensitive tool that is devoid of membrane-bound barriers, yet contains all the mandatory substrates, biomolecules, and machineries required for the synthesis of the desired proteins. It has the potential to overcome loopholes in the current in vivo production systems and is a promising tool in both basic and applied scientific research. It facilitates a simplified organization of desired experiments with a variety of reaction conditions, making CFPS a powerful tool in biological research. It has been used for the expansion of genetic code, assembly of viruses, and in metabolic engineering for production of toxic and complex proteins. Subsequently, CFPS systems have emerged as potent technology for high-throughput production of membrane proteins, enzymes, and therapeutics. The present review highlights the recent advances and uses of CFPS systems in biomedical, therapeutic, and biotechnological applications. Additionally, we highlight possible solutions to the potential biosafety issues that may be encountered while using CFPS technology.
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Affiliation(s)
- Khushal Khambhati
- Department of Biological Sciences and Biotechnology, Institute of Advanced Research, Gandhinagar, India
| | - Gargi Bhattacharjee
- Department of Biological Sciences and Biotechnology, Institute of Advanced Research, Gandhinagar, India
| | - Nisarg Gohil
- Department of Biological Sciences and Biotechnology, Institute of Advanced Research, Gandhinagar, India
| | | | - Vishwesh Kulkarni
- School of Engineering, University of Warwick, Coventry, United Kingdom
| | - Vijai Singh
- Department of Biological Sciences and Biotechnology, Institute of Advanced Research, Gandhinagar, India
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45
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Lehr FX, Hanst M, Vogel M, Kremer J, Göringer HU, Suess B, Koeppl H. Cell-Free Prototyping of AND-Logic Gates Based on Heterogeneous RNA Activators. ACS Synth Biol 2019; 8:2163-2173. [PMID: 31393707 DOI: 10.1021/acssynbio.9b00238] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RNA-based devices controlling gene expression bear great promise for synthetic biology, as they offer many advantages such as short response times and light metabolic burden compared to protein-circuits. However, little work has been done regarding their integration to multilevel regulated circuits. In this work, we combined a variety of small transcriptional activator RNAs (STARs) and toehold switches to build highly effective AND-gates. To characterize the components and their dynamic range, we used an Escherichia coli (E. coli) cell-free transcription-translation (TX-TL) system dispensed via nanoliter droplets. We analyzed a prototype gate in vitro as well as in silico, employing parametrized ordinary differential equations (ODEs), for which parameters were inferred via parallel tempering, a Markov chain Monte Carlo (MCMC) method. On the basis of this analysis, we created nine additional AND-gates and tested them in vitro. The functionality of the gates was found to be highly dependent on the concentration of the activating RNA for either the STAR or the toehold switch. All gates were successfully implemented in vivo, offering a dynamic range comparable to the level of protein circuits. This study shows the potential of a rapid prototyping approach for RNA circuit design, using cell-free systems in combination with a model prediction.
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Affiliation(s)
- François-Xavier Lehr
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Maleen Hanst
- Department of Electrical Engineering, Technische Universität Darmstadt, 64283 Darmstadt, Germany
| | - Marc Vogel
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Jennifer Kremer
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - H. Ulrich Göringer
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Heinz Koeppl
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
- Department of Electrical Engineering, Technische Universität Darmstadt, 64283 Darmstadt, Germany
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Abstract
Cell-free systems (CFS) have recently evolved into key platforms for synthetic biology applications. Many synthetic biology tools have traditionally relied on cell-based systems, and while their adoption has shown great progress, the constraints inherent to the use of cellular hosts have limited their reach and scope. Cell-free systems, which can be thought of as programmable liquids, have removed many of these complexities and have brought about exciting opportunities for rational design and manipulation of biological systems. Here we review how these simple and accessible enzymatic systems are poised to accelerate the rate of advancement in synthetic biology and, more broadly, biotechnology.
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Affiliation(s)
- Aidan Tinafar
- Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, ON, M5S 3M2, Canada
| | - Katariina Jaenes
- Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, ON, M5S 3M2, Canada
| | - Keith Pardee
- Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College St., Toronto, ON, M5S 3M2, Canada.
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47
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Yim SS, Johns NI, Park J, Gomes ALC, McBee RM, Richardson M, Ronda C, Chen SP, Garenne D, Noireaux V, Wang HH. Multiplex transcriptional characterizations across diverse bacterial species using cell-free systems. Mol Syst Biol 2019; 15:e8875. [PMID: 31464371 PMCID: PMC6692573 DOI: 10.15252/msb.20198875] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/01/2019] [Accepted: 07/03/2019] [Indexed: 12/14/2022] Open
Abstract
Cell-free expression systems enable rapid prototyping of genetic programs in vitro. However, current throughput of cell-free measurements is limited by the use of channel-limited fluorescent readouts. Here, we describe DNA Regulatory element Analysis by cell-Free Transcription and Sequencing (DRAFTS), a rapid and robust in vitro approach for multiplexed measurement of transcriptional activities from thousands of regulatory sequences in a single reaction. We employ this method in active cell lysates developed from ten diverse bacterial species. Interspecies analysis of transcriptional profiles from > 1,000 diverse regulatory sequences reveals functional differences in promoter activity that can be quantitatively modeled, providing a rich resource for tuning gene expression in diverse bacterial species. Finally, we examine the transcriptional capacities of dual-species hybrid lysates that can simultaneously harness gene expression properties of multiple organisms. We expect that this cell-free multiplex transcriptional measurement approach will improve genetic part prototyping in new bacterial chassis for synthetic biology.
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Affiliation(s)
- Sung Sun Yim
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
| | - Nathan I Johns
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
- Present address:
Department of BioengineeringStanford UniversityStanfordCAUSA
| | - Jimin Park
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
| | - Antonio LC Gomes
- Department of ImmunologyMemorial Sloan Kettering Cancer CenterNew YorkNYUSA
| | - Ross M McBee
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Department of Biological SciencesColumbia UniversityNew YorkNYUSA
| | - Miles Richardson
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
| | - Carlotta Ronda
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
| | - Sway P Chen
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
| | - David Garenne
- School of Physics and AstronomyUniversity of MinnesotaMinneapolisMNUSA
| | - Vincent Noireaux
- School of Physics and AstronomyUniversity of MinnesotaMinneapolisMNUSA
| | - Harris H Wang
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Department of Pathology and Cell BiologyColumbia UniversityNew YorkNYUSA
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48
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Garenne D, Noireaux V. Cell-free transcription–translation: engineering biology from the nanometer to the millimeter scale. Curr Opin Biotechnol 2019; 58:19-27. [DOI: 10.1016/j.copbio.2018.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/14/2018] [Indexed: 01/01/2023]
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49
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Menon G, Krishnan J. Design Principles for Compartmentalization and Spatial Organization of Synthetic Genetic Circuits. ACS Synth Biol 2019; 8:1601-1619. [PMID: 31257861 DOI: 10.1021/acssynbio.8b00522] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Compartmentalization is a hallmark of cellular systems and an ingredient actively exploited in evolution. It is also being engineered and exploited in synthetic biology, in multiple ways. While these have demonstrated important experimental capabilities, understanding design principles underpinning compartmentalization of genetic circuits has been elusive. We develop a systems framework to elucidate the interplay between the nature of the genetic circuit, the spatial organization of compartments, and their operational state (well-mixed or otherwise). In so doing, we reveal a number of unexpected features associated with compartmentalizing synthetic and template-based circuits. These include (i) the consequences of distributing circuits including trade-offs and how they may be circumvented, (ii) hidden constraints in realizing a distributed circuit, and (iii) appealing new features of compartmentalized circuits. We build on this to examine exemplar applications, which consolidate and extend the design principles we have obtained. Our insights, which emerge from the most basic and general considerations of compartmentalizing genetic circuits, are relevant in a broad range of settings.
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Affiliation(s)
- Govind Menon
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW72AZ, United Kingdom
| | - J. Krishnan
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW72AZ, United Kingdom
- Institute for Systems and Synthetic Biology, Imperial College London, London SW72AZ, United Kingdom
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50
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Kelly CL, Harris AWK, Steel H, Hancock EJ, Heap JT, Papachristodoulou A. Synthetic negative feedback circuits using engineered small RNAs. Nucleic Acids Res 2019; 46:9875-9889. [PMID: 30212900 PMCID: PMC6182179 DOI: 10.1093/nar/gky828] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 09/06/2018] [Indexed: 12/13/2022] Open
Abstract
Negative feedback is known to enable biological and man-made systems to perform reliably in the face of uncertainties and disturbances. To date, synthetic biological feedback circuits have primarily relied upon protein-based, transcriptional regulation to control circuit output. Small RNAs (sRNAs) are non-coding RNA molecules that can inhibit translation of target messenger RNAs (mRNAs). In this work, we modelled, built and validated two synthetic negative feedback circuits that use rationally-designed sRNAs for the first time. The first circuit builds upon the well characterised tet-based autorepressor, incorporating an externally-inducible sRNA to tune the effective feedback strength. This allows more precise fine-tuning of the circuit output in contrast to the sigmoidal, steep input–output response of the autorepressor alone. In the second circuit, the output is a transcription factor that induces expression of an sRNA, which inhibits translation of the mRNA encoding the output, creating direct, closed-loop, negative feedback. Analysis of the noise profiles of both circuits showed that the use of sRNAs did not result in large increases in noise. Stochastic and deterministic modelling of both circuits agreed well with experimental data. Finally, simulations using fitted parameters allowed dynamic attributes of each circuit such as response time and disturbance rejection to be investigated.
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Affiliation(s)
- Ciarán L Kelly
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK.,Imperial College Centre for Synthetic Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Andreas W K Harris
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Harrison Steel
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - Edward J Hancock
- Department of Engineering Science, University of Oxford, Parks Road, Oxford OX1 3PJ, UK
| | - John T Heap
- Imperial College Centre for Synthetic Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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