1
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Chung KP, Loiacono FV, Neupert J, Wu M, Bock R. An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression. Nucleic Acids Res 2023; 51:11386-11400. [PMID: 37855670 PMCID: PMC10639063 DOI: 10.1093/nar/gkad816] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/01/2023] [Accepted: 09/20/2023] [Indexed: 10/20/2023] Open
Abstract
Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are rare, and in organellar genomes, no RNA thermometers have been identified to date. Here we report the discovery of an RNA thermometer in a chloroplast gene of the unicellular green alga Chlamydomonas reinhardtii. The thermometer, residing in the 5' untranslated region of the psaA messenger RNA forms a hairpin-type secondary structure that masks the Shine-Dalgarno sequence at 25°C. At 40°C, melting of the secondary structure increases accessibility of the Shine-Dalgarno sequence to initiating ribosomes, thus enhancing protein synthesis. By targeted nucleotide substitutions and transfer of the thermometer into Escherichia coli, we show that the secondary structure is necessary and sufficient to confer the thermometer properties. We also demonstrate that the thermometer provides a valuable tool for inducible transgene expression from the Chlamydomonas plastid genome, in that a simple temperature shift of the algal culture can greatly increase recombinant protein yields.
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Affiliation(s)
- Kin Pan Chung
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - F Vanessa Loiacono
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Juliane Neupert
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Mengting Wu
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Department Organelle Biology, Biotechnology and Molecular Ecophysiology, Am Mühlenberg 1, D-14476 Potsdam-Golm, Germany
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2
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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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3
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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: 4] [Impact Index Per Article: 2.0] [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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4
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Xiong LL, Garrett MA, Buss MT, Kornfield JA, Shapiro MG. Tunable Temperature-Sensitive Transcriptional Activation Based on Lambda Repressor. ACS Synth Biol 2022; 11:2518-2522. [PMID: 35708251 PMCID: PMC9295150 DOI: 10.1021/acssynbio.2c00093] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Temperature is a
versatile input signal for the control of engineered
cellular functions. Sharp induction of gene expression with heat has
been established using bacteria- and phage-derived temperature-sensitive
transcriptional repressors with tunable switching temperatures. However,
few temperature-sensitive transcriptional activators have been reported
that enable direct gene induction with cooling. Such activators would
expand the application space for temperature control. In this technical
note, we show that temperature-dependent versions of the Lambda phage
repressor CI can serve as tunable cold-actuated transactivators. Natively,
CI serves as both a repressor and activator of transcription. Previously,
thermolabile mutants of CI, known as the TcI family, were used to
repress the cognate promoters PR and PL. We hypothesized that TcI
mutants can also serve as temperature-sensitive activators of transcription
at CI’s natural PRM promoter, creating cold-inducible operons
with a tunable response to temperature. Indeed, we demonstrate temperature-responsive
activation by two variants of TcI with set points at 35.5 and 38.5
°C in E. coli. In addition, we show that
TcI can serve as both an activator and a repressor of different genes
in the same genetic circuit, leading to opposite thermal responses.
Transcriptional activation by TcI expands the toolbox for control
of cellular function using globally or locally applied thermal inputs.
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Affiliation(s)
- Lealia L Xiong
- Division of Engineering and Applied Sciences, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, United States
| | - Michael A Garrett
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, United States
| | - Marjorie T Buss
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, United States
| | - Julia A Kornfield
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, United States
| | - Mikhail G Shapiro
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, United States.,Howard Hughes Medical Institute, California Institute of Technology, 1200 E. California Blvd., Pasadena, California 91125, United States
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5
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Yang J, Wang C, Lu Y. A Temperature-Controlled Cell-Free Expression System by Dynamic Repressor. ACS Synth Biol 2022; 11:1408-1416. [PMID: 35319196 DOI: 10.1021/acssynbio.1c00641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The cell-free protein synthesis (CFPS) system is a typical protein production platform in the field of synthetic biology. However, there are limitations in controlling protein synthesis in the CFPS system. Compared with the traditional method of adding chemicals, temperature is an ideal control switch to achieve precise spatiotemporal control with few side effects. Hence, the design of a temperature-controlled cell-free protein synthesis (tcCFPS) system based on E. coli was carried out with the repressor cI protein in this study. The corresponding tcCFPS achieved a 143-fold dynamic protein expression level at 37 °C than that at 30 °C. Besides, the artificial cell controlled by temperature was constructed to expand the applications of tcCFPS. This study provides a new effective method for active protein synthesis in a cell-free system and a potential means of drug synthesis and delivery.
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Affiliation(s)
- Junzhu Yang
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Chen Wang
- 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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6
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Li L, Pan H, Pang G, Lang H, Shen Y, Sun T, Zhang Y, Liu J, Chang J, Kang J, Zheng H, Wang H. Precise Thermal Regulation of Engineered Bacteria Secretion for Breast Cancer Treatment In Vivo. ACS Synth Biol 2022; 11:1167-1177. [PMID: 35175748 DOI: 10.1021/acssynbio.1c00452] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
For the biomedical application of engineered bacteria, strictly regulating the function of engineered bacteria has always been the goal pursued. However, the existing regulation methods do not meet the needs of the in vivo application of engineered bacteria. Therefore, the exploration of the precise regulation of engineered bacteria is necessary. Herein, heat-sensitive engineered bacteria that can respond to thermal stimuli within 30 min were constructed, and the precise control of functions was verified in the intestines of various model organisms (including C. elegans, bees, and mice). Subsequently, heat-sensitive engineered bacteria were shown to colonize the mouse tumor microenvironment. Finally, thermal stimulation was proven to control engineered bacteria to produce the therapeutic protein tumor necrosis factor α (TNF-α) in the tumor. After three heat stimulation treatments, the growth of the tumor was significantly inhibited, suggesting that heat can be used as a strategy to precisely control engineered bacteria in vivo.
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Affiliation(s)
- Lianyue Li
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Huizhuo Pan
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Gaoju Pang
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Haoyu Lang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Yue Shen
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Tao Sun
- Center for Biosafety Research and Strategy, Tianjin University, Tianjin, 300072, China
- Laboratory of Synthetic Microbiology, School of Chemical Engineering & Technology, Tianjin University, Tianjin, 300072, China
| | - Yingying Zhang
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Jing Liu
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
| | - Jin Chang
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Jun Kang
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
| | - Hao Zheng
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Hanjie Wang
- School of Life Sciences, Tianjin University, Tianjin, 300072, China
- Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology, Tianjin Key Laboratory of Function and Application of Biological Macromolecular Structures, Tianjin, 300072, China
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7
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Chee WKD, Yeoh JW, Dao VL, Poh CL. Highly Reversible Tunable Thermal-Repressible Split-T7 RNA Polymerases (Thermal-T7RNAPs) for Dynamic Gene Regulation. ACS Synth Biol 2022; 11:921-937. [PMID: 35089710 DOI: 10.1021/acssynbio.1c00545] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Temperature is a physical cue that is easy to apply, allowing cellular behaviors to be controlled in a contactless and dynamic manner via heat-inducible/repressible systems. However, existing heat-repressible systems are limited in number, rely on thermal sensitive mRNA or transcription factors that function at low temperatures, lack tunability, suffer delays, and are overly complex. To provide an alternative mode of thermal regulation, we developed a library of compact, reversible, and tunable thermal-repressible split-T7 RNA polymerase systems (Thermal-T7RNAPs), which fused temperature-sensitive domains of Tlpa protein with split-T7RNAP to enable direct thermal control of the T7RNAP activity between 30 and 42 °C. We generated a large mutant library with varying thermal performances via an automated screening framework to extend temperature tunability. Lastly, using the mutants, novel thermal logic circuitry was implemented to regulate cell growth and achieve active thermal control of the cell proportions within co-cultures. Overall, this technology expanded avenues for thermal control in biotechnology applications.
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Affiliation(s)
- Wai Kit David Chee
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, 117456 Singapore
| | - Jing Wui Yeoh
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, 117456 Singapore
| | - Viet Linh Dao
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, 117456 Singapore
| | - Chueh Loo Poh
- Department of Biomedical Engineering, College of Design and Engineering, National University of Singapore, 4 Engineering Drive 3, 117583 Singapore
- NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), National University of Singapore, 28 Medical Drive, 117456 Singapore
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8
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Sharma A, Alajangi HK, Pisignano G, Sood V, Singh G, Barnwal RP. RNA thermometers and other regulatory elements: Diversity and importance in bacterial pathogenesis. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1711. [PMID: 35037405 DOI: 10.1002/wrna.1711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 11/09/2021] [Accepted: 12/16/2021] [Indexed: 01/11/2023]
Abstract
Survival of microorganisms depends to a large extent on environmental conditions and the occupied host. By adopting specific strategies, microorganisms can thrive in the surrounding environment and, at the same time, preserve their viability. Evading the host defenses requires several mechanisms compatible with the host survival which include the production of RNA thermometers to regulate the expression of genes responsible for heat or cold shock as well as of those involved in virulence. Microorganisms have developed a variety of molecules in response to the environmental changes in temperature and even more specifically to the host they invade. Among all, RNA-based regulatory mechanisms are the most common ones, highlighting the importance of such molecules in gene expression control and novel drug development by suitable structure-based alterations. This article is categorized under: RNA Structure and Dynamics > RNA Structure, Dynamics and Chemistry RNA in Disease and Development > RNA in Disease RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Akanksha Sharma
- Department of Biophysics, Panjab University, Chandigarh, India.,University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
| | - Hema Kumari Alajangi
- Department of Biophysics, Panjab University, Chandigarh, India.,University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
| | | | - Vikas Sood
- Department of Biochemistry, Jamia Hamdard, New Delhi, India
| | - Gurpal Singh
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
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9
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Chee WKD, Yeoh JW, Dao VL, Poh CL. Thermogenetics: Applications come of age. Biotechnol Adv 2022; 55:107907. [PMID: 35041863 DOI: 10.1016/j.biotechadv.2022.107907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/13/2021] [Accepted: 01/09/2022] [Indexed: 12/20/2022]
Abstract
Temperature is a ubiquitous physical cue that is non-invasive, penetrative and easy to apply. In the growing field of thermogenetics, through beneficial repurposing of natural thermosensing mechanisms, synthetic biology is bringing new opportunities to design and build robust temperature-sensitive (TS) sensors which forms a thermogenetic toolbox of well characterised biological parts. Recent advancements in technological platforms available have expedited the discovery of novel or de novo thermosensors which are increasingly deployed in many practical temperature-dependent biomedical, industrial and biosafety applications. In all, the review aims to convey both the exhilarating recent technological developments underlying the advancement of thermosensors and the exciting opportunities the nascent thermogenetic field holds for biomedical and biotechnology applications.
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Affiliation(s)
- Wai Kit David Chee
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Jing Wui Yeoh
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Viet Linh Dao
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Chueh Loo Poh
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
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10
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Smith JM, Chowdhry R, Booth MJ. Controlling Synthetic Cell-Cell Communication. Front Mol Biosci 2022; 8:809945. [PMID: 35071327 PMCID: PMC8766733 DOI: 10.3389/fmolb.2021.809945] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 12/13/2021] [Indexed: 11/28/2022] Open
Abstract
Synthetic cells, which mimic cellular function within a minimal compartment, are finding wide application, for instance in studying cellular communication and as delivery devices to living cells. However, to fully realise the potential of synthetic cells, control of their function is vital. An array of tools has already been developed to control the communication of synthetic cells to neighbouring synthetic cells or living cells. These tools use either chemical inputs, such as small molecules, or physical inputs, such as light. Here, we examine these current methods of controlling synthetic cell communication and consider alternative mechanisms for future use.
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Affiliation(s)
| | | | - Michael J. Booth
- Chemistry Research Laboratory, University of Oxford, Oxford, United Kingdom
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11
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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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12
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Greco FV, Irvine T, Grierson CS, Gorochowski TE. Design and Assembly of Multilevel Transcriptional and Translational Regulators for Stringent Control of Gene Expression. Methods Mol Biol 2022; 2518:99-110. [PMID: 35666441 DOI: 10.1007/978-1-0716-2421-0_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Precise control of gene expression is crucial when reprogramming the behavior of living cells. However, common inducible systems often lack the ability to stringently control gene expression due to the use of a single type of regulator that can be susceptible to unavoidable biomolecular fluctuations. In contrast, multilevel controllers (MLCs) employ several forms of regulation simultaneously to overcome this issue, ensuring a reduced basal expression while minimally affecting the maximum induced expression level that can be achieved. Here, we show how our publicly available genetic toolkit can be used to simplify the assembly of MLCs for the stringent control of gene expression. We demonstrate how new compatible parts can be designed and explain the rapid end-to-end assembly procedure.
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Affiliation(s)
- F Veronica Greco
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Thea Irvine
- School of Biological Sciences, University of Bristol, Bristol, UK
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13
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Sen S, Patel A, Gola KK. Design of a Toolbox of RNA Thermometers. Methods Mol Biol 2022; 2518:125-133. [PMID: 35666443 DOI: 10.1007/978-1-0716-2421-0_8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
RNA thermometers are RNA regulatory elements that convert temperature into a functional biological response through a temperature-induced conformational change. These regulatory elements have been investigated in numerous natural contexts and have been designed for synthetic biology as well. A basic challenge has been the design of an RNA thermometer whose final activity in response to temperature matches a prespecified response, in terms of its sensitivity, threshold, and leakiness. This chapter provides a methodology for the design of a toolbox of RNA thermometers. We describe considerations for the conceptual design, a computational assessment, and strategies for experimental synthesis and measurement.
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Affiliation(s)
- Shaunak Sen
- Department of Electrical Engineering, IIT Delhi, New Delhi, India.
| | - Abhilash Patel
- Department of Bioengineering, Imperial College, London, UK
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14
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Restrepo-Pineda S, Pérez NO, Valdez-Cruz NA, Trujillo-Roldán MA. Thermoinducible expression system for producing recombinant proteins in Escherichia coli: advances and insights. FEMS Microbiol Rev 2021; 45:6223457. [PMID: 33844837 DOI: 10.1093/femsre/fuab023] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 04/09/2021] [Indexed: 12/13/2022] Open
Abstract
Recombinant protein (RP) production from Escherichia coli has been extensively studied to find strategies for increasing product yields. The thermoinducible expression system is commonly employed at the industrial level to produce various RPs which avoids the addition of chemical inducers, thus minimizing contamination risks. Multiple aspects of the molecular origin and biotechnological uses of its regulatory elements (pL/pR promoters and cI857 thermolabile repressor) derived from bacteriophage λ provide knowledge to improve the bioprocesses using this system. Here, we discuss the main aspects of the potential use of the λpL/pR-cI857 thermoinducible system for RP production in E. coli, focusing on the approaches of investigations that have contributed to the advancement of this expression system. Metabolic and physiological changes that occur in the host cells caused by heat stress and by RP overproduction are also described. Therefore, the current scenario and the future applications of systems that use heat to induce RP production is discussed to understand the relationship between the activation of the bacterial heat shock response, RP accumulation, and its possible aggregation to form inclusion bodies.
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Affiliation(s)
- Sara Restrepo-Pineda
- Unidad de Bioprocesos, Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Ciudad de México, México
| | - Néstor O Pérez
- Probiomed S.A. de C.V. Planta Tenancingo, Cruce de Carreteras Acatzingo-Zumpahuacan SN, 52400 Tenancingo, Estado de México, México
| | - Norma A Valdez-Cruz
- Unidad de Bioprocesos, Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Ciudad de México, México
| | - Mauricio A Trujillo-Roldán
- Unidad de Bioprocesos, Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510, Ciudad de México, México
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15
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Harnessing the central dogma for stringent multi-level control of gene expression. Nat Commun 2021; 12:1738. [PMID: 33741937 PMCID: PMC7979795 DOI: 10.1038/s41467-021-21995-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 02/18/2021] [Indexed: 11/17/2022] Open
Abstract
Strictly controlled inducible gene expression is crucial when engineering biological systems where even tiny amounts of a protein have a large impact on function or host cell viability. In these cases, leaky protein production must be avoided, but without affecting the achievable range of expression. Here, we demonstrate how the central dogma offers a simple solution to this challenge. By simultaneously regulating transcription and translation, we show how basal expression of an inducible system can be reduced, with little impact on the maximum expression rate. Using this approach, we create several stringent expression systems displaying >1000-fold change in their output after induction and show how multi-level regulation can suppress transcriptional noise and create digital-like switches between ‘on’ and ‘off’ states. These tools will aid those working with toxic genes or requiring precise regulation and propagation of cellular signals, plus illustrate the value of more diverse regulatory designs for synthetic biology. Inducible gene expression systems should minimise leaky output and offer a large achievable range of expression. Here, the authors regulate transcription and translation together to suppress noise and create digital-like responses, while maintaining a large expression range in vivo and in vitro.
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16
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Del Valle I, Fulk EM, Kalvapalle P, Silberg JJ, Masiello CA, Stadler LB. Translating New Synthetic Biology Advances for Biosensing Into the Earth and Environmental Sciences. Front Microbiol 2021; 11:618373. [PMID: 33633695 PMCID: PMC7901896 DOI: 10.3389/fmicb.2020.618373] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/17/2020] [Indexed: 12/26/2022] Open
Abstract
The rapid diversification of synthetic biology tools holds promise in making some classically hard-to-solve environmental problems tractable. Here we review longstanding problems in the Earth and environmental sciences that could be addressed using engineered microbes as micron-scale sensors (biosensors). Biosensors can offer new perspectives on open questions, including understanding microbial behaviors in heterogeneous matrices like soils, sediments, and wastewater systems, tracking cryptic element cycling in the Earth system, and establishing the dynamics of microbe-microbe, microbe-plant, and microbe-material interactions. Before these new tools can reach their potential, however, a suite of biological parts and microbial chassis appropriate for environmental conditions must be developed by the synthetic biology community. This includes diversifying sensing modules to obtain information relevant to environmental questions, creating output signals that allow dynamic reporting from hard-to-image environmental materials, and tuning these sensors so that they reliably function long enough to be useful for environmental studies. Finally, ethical questions related to the use of synthetic biosensors in environmental applications are discussed.
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Affiliation(s)
- Ilenne Del Valle
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, TX, United States
| | - Emily M. Fulk
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, TX, United States
| | - Prashant Kalvapalle
- Systems, Synthetic, and Physical Biology Graduate Program, Rice University, Houston, TX, United States
| | - Jonathan J. Silberg
- Department of BioSciences, Rice University, Houston, TX, United States
- Department of Bioengineering, Rice University, Houston, TX, United States
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, United States
| | - Caroline A. Masiello
- Department of BioSciences, Rice University, Houston, TX, United States
- Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX, United States
- Department of Chemistry, Rice University, Houston, TX, United States
| | - Lauren B. Stadler
- Department of Civil and Environmental Engineering, Rice University, Houston, TX, United States
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17
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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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18
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Schramm T, Lempp M, Beuter D, Sierra SG, Glatter T, Link H. High-throughput enrichment of temperature-sensitive argininosuccinate synthetase for two-stage citrulline production in E. coli. Metab Eng 2020; 60:14-24. [PMID: 32179161 PMCID: PMC7225747 DOI: 10.1016/j.ymben.2020.03.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 03/03/2020] [Accepted: 03/08/2020] [Indexed: 12/20/2022]
Abstract
Controlling metabolism of engineered microbes is important to modulate cell growth and production during a bioprocess. For example, external parameters such as light, chemical inducers, or temperature can act on metabolism of production strains by changing the abundance or activity of enzymes. Here, we created temperature-sensitive variants of an essential enzyme in arginine biosynthesis of Escherichia coli (argininosuccinate synthetase, ArgG) and used them to dynamically control citrulline overproduction and growth of E. coli. We show a method for high-throughput enrichment of temperature-sensitive ArgG variants with a fluorescent TIMER protein and flow cytometry. With 90 of the thus derived ArgG variants, we complemented an ArgG deletion strain showing that 90% of the strains exhibit temperature-sensitive growth and 69% of the strains are auxotrophic for arginine at 42 °C and prototrophic at 30 °C. The best temperature-sensitive ArgG variant enabled precise and tunable control of cell growth by temperature changes. Expressing this variant in a feedback-dysregulated E. coli strain allowed us to realize a two-stage bioprocess: a 33 °C growth-phase for biomass accumulation and a 39 °C stationary-phase for citrulline production. With this two-stage strategy, we produced 3 g/L citrulline during 45 h cultivation in a 1-L bioreactor. These results show that temperature-sensitive enzymes can be created en masse and that they may function as metabolic valves in engineered bacteria. Method to enrich temperature-sensitive enzymes en masse. Temperature-sensitive enzymes function as metabolic valve. Temperature controlled two-stage production of citrulline.
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Affiliation(s)
- Thorben Schramm
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany
| | - Martin Lempp
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany
| | - Dominik Beuter
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany
| | - Silvia González Sierra
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany
| | - Timo Glatter
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany
| | - Hannes Link
- Max Planck Institute for Terrestrial Microbiology, Karl-von-Frisch-Strasse 16, 35043, Marburg, Germany.
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19
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Gamboa L, Zamat AH, Kwong GA. Synthetic immunity by remote control. Theranostics 2020; 10:3652-3667. [PMID: 32206114 PMCID: PMC7069089 DOI: 10.7150/thno.41305] [Citation(s) in RCA: 12] [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: 10/18/2019] [Accepted: 02/03/2020] [Indexed: 12/11/2022] Open
Abstract
Cell-based immunotherapies, such as T cells engineered with chimeric antigen receptors (CARs), have the potential to cure patients of disease otherwise refractory to conventional treatments. Early-on-treatment and long-term durability of patient responses depend critically on the ability to control the potency of adoptively transferred T cells, as overactivation can lead to complications like cytokine release syndrome, and immunosuppression can result in ineffective responses to therapy. Drugs or biologics (e.g., cytokines) that modulate immune activity are limited by mass transport barriers that reduce the local effective drug concentration, and lack site or target cell specificity that results in toxicity. Emerging technologies that enable site-targeted, remote control of key T cell functions - including proliferation, antigen-sensing, and target-cell killing - have the potential to increase treatment precision and safety profile. These technologies are broadly applicable to other immune cells to expand immune cell therapies across many cancers and diseases. In this review, we highlight the opportunities, challenges and the current state-of-the-art for remote control of synthetic immunity.
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Affiliation(s)
- Lena Gamboa
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA 30332, USA
| | - Ali H. Zamat
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA 30332, USA
| | - Gabriel A. Kwong
- The Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology & Emory University, Atlanta, GA 30332, USA
- Institute for Electronics and Nanotechnology, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Parker H. Petit Institute of Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Integrated Cancer Research Center, Georgia Institute of Technology, Atlanta, GA 30332, USA
- Georgia Immunoengineering Consortium, Emory University and Georgia Institute of Technology, Atlanta, GA 30332, USA
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20
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Abstract
Temperature is an important parameter in bioprocesses, influencing the structure and functionality of almost every biomolecule, as well as affecting metabolic reaction rates. In industrial biotechnology, the temperature is usually tightly controlled at an optimum value. Smart variation of the temperature to optimize the performance of a bioprocess brings about multiple complex and interconnected metabolic changes and is so far only rarely applied. Mathematical descriptions and models facilitate a reduction in complexity, as well as an understanding, of these interconnections. Starting in the 19th century with the “primal” temperature model of Svante Arrhenius, a variety of models have evolved over time to describe growth and enzymatic reaction rates as functions of temperature. Data-driven empirical approaches, as well as complex mechanistic models based on thermodynamic knowledge of biomolecular behavior at different temperatures, have been developed. Even though underlying biological mechanisms and mathematical models have been well-described, temperature as a control variable is only scarcely applied in bioprocess engineering, and as a conclusion, an exploitation strategy merging both in context has not yet been established. In this review, the most important models for physiological, biochemical, and physical properties governed by temperature are presented and discussed, along with application perspectives. As such, this review provides a toolset for future exploitation perspectives of temperature in bioprocess engineering.
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21
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Noll P, Treinen C, Müller S, Senkalla S, Lilge L, Hausmann R, Henkel M. Evaluating temperature-induced regulation of a ROSE-like RNA-thermometer for heterologous rhamnolipid production in Pseudomonas putida KT2440. AMB Express 2019; 9:154. [PMID: 31555921 PMCID: PMC6761213 DOI: 10.1186/s13568-019-0883-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Accepted: 09/17/2019] [Indexed: 11/24/2022] Open
Abstract
The microbial production of rhamnolipids has been in the focus of research for the last decades. Today, mainly heterologous production systems are targeted due to the advantage of non-pathogenic hosts as well as uncoupling from complex quorum sensing regulatory networks compared to their natural producer Pseudomonas aeruginosa. In the recent past, the presence and function of a ROSE-like RNA-thermometer located in the 5′UTR of the rhamnosyltransferase genes rhlAB has been reported in wild type P. aeruginosa. In this study, the temperature-induced regulation of this native RNA-thermometer for heterologous rhamnolipid production was evaluated and its potential application for process control is discussed. For this purpose, the non-pathogenic production host P. putida KT2440 containing the rhlAB genes with the native P. aeruginosa 5′-UTR region was used. The system was evaluated and characterized regarding the effect of temperature on growth and product formation, as represented by efficiency parameters and yields. Experimental data suggests a major effect of temperature on specific rhamnolipid production rates. With maximum values of 0.23 g/(g h) at 37 °C, this constitutes a more than 60% increase compared to the production rate of 0.14 g/(g h) at the growth optimum of 30 °C. Interestingly however, control experiments unveiled that besides the regulatory effect of the RNA-thermometer, multiple metabolic effects may contribute equally to the observed increase in production rate. As such, this work constitutes an important step towards the utilization of temperature-based process designs and enables the possibility for novel approaches for process control.
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22
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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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23
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Bervoets I, Charlier D. Diversity, versatility and complexity of bacterial gene regulation mechanisms: opportunities and drawbacks for applications in synthetic biology. FEMS Microbiol Rev 2019; 43:304-339. [PMID: 30721976 PMCID: PMC6524683 DOI: 10.1093/femsre/fuz001] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Accepted: 01/21/2019] [Indexed: 12/15/2022] Open
Abstract
Gene expression occurs in two essential steps: transcription and translation. In bacteria, the two processes are tightly coupled in time and space, and highly regulated. Tight regulation of gene expression is crucial. It limits wasteful consumption of resources and energy, prevents accumulation of potentially growth inhibiting reaction intermediates, and sustains the fitness and potential virulence of the organism in a fluctuating, competitive and frequently stressful environment. Since the onset of studies on regulation of enzyme synthesis, numerous distinct regulatory mechanisms modulating transcription and/or translation have been discovered. Mostly, various regulatory mechanisms operating at different levels in the flow of genetic information are used in combination to control and modulate the expression of a single gene or operon. Here, we provide an extensive overview of the very diverse and versatile bacterial gene regulatory mechanisms with major emphasis on their combined occurrence, intricate intertwinement and versatility. Furthermore, we discuss the potential of well-characterized basal expression and regulatory elements in synthetic biology applications, where they may ensure orthogonal, predictable and tunable expression of (heterologous) target genes and pathways, aiming at a minimal burden for the host.
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Affiliation(s)
- Indra Bervoets
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
| | - Daniel Charlier
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium
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24
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Jia H, Heymann M, Härtel T, Kai L, Schwille P. Temperature-sensitive protein expression in protocells. Chem Commun (Camb) 2019; 55:6421-6424. [PMID: 31094370 DOI: 10.1039/c9cc02734c] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We engineered a synthetic temperature regulation toolbox to enable protocells to sense and respond to heat, utilizing RNA thermometers. The thermo-sensitive protocells were generated by encapsulating temperature feedback transcription/translation machinery in droplets. Based on these temperature-sensing devices, the protocells can be operated with logic AND gates, differentially processing temperature stimuli into biological signals.
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Affiliation(s)
- Haiyang Jia
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D - 82152 Martinsried, Germany.
| | - Michael Heymann
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D - 82152 Martinsried, Germany.
| | - Tobias Härtel
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D - 82152 Martinsried, Germany.
| | - Lei Kai
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D - 82152 Martinsried, Germany.
| | - Petra Schwille
- Dept. Cellular and Molecular Biophysics, Max Planck Institute of Biochemistry, Am Klopferspitz 18, D - 82152 Martinsried, Germany.
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25
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Nshogozabahizi J, Aubrey K, Ross J, Thakor N. Applications and limitations of regulatory
RNA
elements in synthetic biology and biotechnology. J Appl Microbiol 2019; 127:968-984. [DOI: 10.1111/jam.14270] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/09/2019] [Accepted: 03/21/2019] [Indexed: 12/13/2022]
Affiliation(s)
- J.C. Nshogozabahizi
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
| | - K.L. Aubrey
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
| | - J.A. Ross
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
| | - N. Thakor
- Department of Chemistry and Biochemistry Alberta RNA Research and Training Institute (ARRTI) University of Lethbridge Lethbridge AB Canada
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26
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Gregorio NE, Levine MZ, Oza JP. A User's Guide to Cell-Free Protein Synthesis. Methods Protoc 2019; 2:E24. [PMID: 31164605 PMCID: PMC6481089 DOI: 10.3390/mps2010024] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/05/2019] [Accepted: 03/06/2019] [Indexed: 02/06/2023] Open
Abstract
Cell-free protein synthesis (CFPS) is a platform technology that provides new opportunities for protein expression, metabolic engineering, therapeutic development, education, and more. The advantages of CFPS over in vivo protein expression include its open system, the elimination of reliance on living cells, and the ability to focus all system energy on production of the protein of interest. Over the last 60 years, the CFPS platform has grown and diversified greatly, and it continues to evolve today. Both new applications and new types of extracts based on a variety of organisms are current areas of development. However, new users interested in CFPS may find it challenging to implement a cell-free platform in their laboratory due to the technical and functional considerations involved in choosing and executing a platform that best suits their needs. Here we hope to reduce this barrier to implementing CFPS by clarifying the similarities and differences amongst cell-free platforms, highlighting the various applications that have been accomplished in each of them, and detailing the main methodological and instrumental requirement for their preparation. Additionally, this review will help to contextualize the landscape of work that has been done using CFPS and showcase the diversity of applications that it enables.
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Affiliation(s)
- Nicole E Gregorio
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
| | - Max Z Levine
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
- Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
| | - Javin P Oza
- Center for Applications in Biotechnology, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407, USA.
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27
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Leonarski F, Jasiński M, Trylska J. Thermodynamics of the fourU RNA thermal switch derived from molecular dynamics simulations and spectroscopic techniques. Biochimie 2018; 156:22-32. [PMID: 30244136 DOI: 10.1016/j.biochi.2018.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Accepted: 09/10/2018] [Indexed: 10/28/2022]
Abstract
Bacterial 5' untranslated regions of mRNA, termed thermal switches or thermometers, change their structure in response to temperature change. This structural change provides for the regulation of gene expression. One of such thermal switches, called fourU, is present in the Salmonella species. Mutations of fourU were found to abrogate its regulatory properties. We investigated the thermodynamics of the fourU fragment responsible for its structural changes. All-atom molecular dynamics simulations at various temperatures and spectroscopic experiments in solution were performed for the wild-type fourU and its mutants. We found that the U11C and A8C mutations stabilize the fourU structure in comparison to the wild-type fourU, and the double-point G14A/C25U mutant has the most destabilizing effect on the fourU hairpin 2 responsible for temperature sensing. The G14A/C25U mutant is also the easiest to strand-invade by a complementary oligonucleotide as indicated by fluorescence spectroscopy experiments.
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Affiliation(s)
- Filip Leonarski
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Maciej Jasiński
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland
| | - Joanna Trylska
- Centre of New Technologies, University of Warsaw, Banacha 2c, 02-097, Warsaw, Poland.
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28
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de Frias UA, Pereira GKB, Guazzaroni ME, Silva-Rocha R. Boosting Secondary Metabolite Production and Discovery through the Engineering of Novel Microbial Biosensors. BIOMED RESEARCH INTERNATIONAL 2018; 2018:7021826. [PMID: 30079350 PMCID: PMC6069586 DOI: 10.1155/2018/7021826] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Accepted: 02/11/2018] [Indexed: 01/05/2023]
Abstract
Bacteria are a source of a large number of secondary metabolites with several biomedical and biotechnological applications. In recent years, there has been tremendous progress in the development of novel synthetic biology approaches both to increase the production rate of secondary metabolites of interest in native producers and to mine and reconstruct novel biosynthetic gene clusters in heterologous hosts. Here, we present the recent advances toward the engineering of novel microbial biosensors to detect the synthesis of secondary metabolites in bacteria and in the development of synthetic promoters and expression systems aiming at the construction of microbial cell factories for the production of these compounds. We place special focus on the potential of Gram-negative bacteria as a source of biosynthetic gene clusters and hosts for pathway assembly, on the construction and characterization of novel promoters for native hosts, and on the use of computer-aided design of novel pathways and expression systems for secondary metabolite production. Finally, we discuss some of the potentials and limitations of the approaches that are currently being developed and we highlight new directions that could be addressed in the field.
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Affiliation(s)
| | | | - María-Eugenia Guazzaroni
- Faculty of Philosophy, Science and Letters of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Rafael Silva-Rocha
- Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil
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29
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Jiang L, Zhao J, Lian J, Xu Z. Cell-free protein synthesis enabled rapid prototyping for metabolic engineering and synthetic biology. Synth Syst Biotechnol 2018; 3:90-96. [PMID: 29900421 PMCID: PMC5995451 DOI: 10.1016/j.synbio.2018.02.003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 02/11/2018] [Accepted: 02/14/2018] [Indexed: 11/15/2022] Open
Abstract
Advances in metabolic engineering and synthetic biology have facilitated the manufacturing of many valuable-added compounds and commodity chemicals using microbial cell factories in the past decade. However, due to complexity of cellular metabolism, the optimization of metabolic pathways for maximal production represents a grand challenge and an unavoidable barrier for metabolic engineering. Recently, cell-free protein synthesis system (CFPS) has been emerging as an enabling alternative to address challenges in biomanufacturing. This review summarizes the recent progresses of CFPS in rapid prototyping of biosynthetic pathways and genetic circuits (biosensors) to speed up design-build-test (DBT) cycles of metabolic engineering and synthetic biology.
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Affiliation(s)
- Lihong Jiang
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jiarun Zhao
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jiazhang Lian
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhinan Xu
- Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
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30
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Roßmanith J, Weskamp M, Narberhaus F. Design of a Temperature-Responsive Transcription Terminator. ACS Synth Biol 2018; 7:613-621. [PMID: 29191010 DOI: 10.1021/acssynbio.7b00356] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
RNA structures regulate various steps in gene expression. Transcription in bacteria is typically terminated by stable hairpin structures. Translation initiation can be modulated by metabolite- or temperature-sensitive RNA structures, called riboswitches or RNA thermometers (RNATs), respectively. RNATs control translation initiation by occlusion of the ribosome binding site at low temperatures. Increasing temperatures destabilize the RNA structure and facilitate ribosome access. In this study, we exploited temperature-responsive RNAT structures to design regulatory elements that control transcription termination instead of translation initiation in Escherichia coli. In order to mimic the structure of factor-independent intrinsic terminators, naturally occurring RNAT hairpins were genetically engineered to be followed by a U-stretch. Functional temperature-responsive terminators (thermoterms) prevented mRNA synthesis at low temperatures but resumed transcription after a temperature upshift. The successful design of temperature-controlled terminators highlights the potential of RNA structures as versatile gene expression control elements.
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Affiliation(s)
| | - Mareen Weskamp
- Microbial Biology, Ruhr University Bochum, 44780 Bochum, Germany
| | - Franz Narberhaus
- Microbial Biology, Ruhr University Bochum, 44780 Bochum, Germany
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31
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Potential Applications of the Escherichia coli Heat Shock Response in Synthetic Biology. Trends Biotechnol 2018; 36:186-198. [DOI: 10.1016/j.tibtech.2017.10.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Revised: 10/20/2017] [Accepted: 10/20/2017] [Indexed: 01/06/2023]
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32
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Abstract
Cell-free synthetic biology approaches enable engineering of biomolecular systems exhibiting complex, cell-like behaviors in the absence of living entities. Often essential to these systems are user-controllable mechanisms to regulate gene expression. Here we describe synthetic RNA thermometers that enable temperature-dependent translation in the PURExpress in vitro protein synthesis system. Previously described cellular thermometers lie wholly in the 5' untranslated region and do not retain their intended function in PURExpress. By contrast, we designed hairpins between the Shine-Dalgarno sequence and complementary sequences within the gene of interest. The resulting thermometers enable high-yield, cell-free protein expression in an inducible temperature range compatible with in vitro translation systems (30-37 °C). Moreover, expression efficiency and switching behavior are tunable via small variations to the coding sequence. Our approach and resulting thermometers provide new tools for exploiting temperature as a rapid, external trigger for in vitro gene regulation.
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Affiliation(s)
- Fredrik W. Sadler
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Igor Dodevski
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
| | - Casim A. Sarkar
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455
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