1
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Rothschild LJ, Averesch NJH, Strychalski EA, Moser F, Glass JI, Cruz Perez R, Yekinni IO, Rothschild-Mancinelli B, Roberts Kingman GA, Wu F, Waeterschoot J, Ioannou IA, Jewett MC, Liu AP, Noireaux V, Sorenson C, Adamala KP. Building Synthetic Cells─From the Technology Infrastructure to Cellular Entities. ACS Synth Biol 2024; 13:974-997. [PMID: 38530077 PMCID: PMC11037263 DOI: 10.1021/acssynbio.3c00724] [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: 12/01/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 03/27/2024]
Abstract
The de novo construction of a living organism is a compelling vision. Despite the astonishing technologies developed to modify living cells, building a functioning cell "from scratch" has yet to be accomplished. The pursuit of this goal alone has─and will─yield scientific insights affecting fields as diverse as cell biology, biotechnology, medicine, and astrobiology. Multiple approaches have aimed to create biochemical systems manifesting common characteristics of life, such as compartmentalization, metabolism, and replication and the derived features, evolution, responsiveness to stimuli, and directed movement. Significant achievements in synthesizing each of these criteria have been made, individually and in limited combinations. Here, we review these efforts, distinguish different approaches, and highlight bottlenecks in the current research. We look ahead at what work remains to be accomplished and propose a "roadmap" with key milestones to achieve the vision of building cells from molecular parts.
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Affiliation(s)
- Lynn J. Rothschild
- Space Science
& Astrobiology Division, NASA Ames Research
Center, Moffett
Field, California 94035-1000, United States
- Department
of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island 02912, United States
| | - Nils J. H. Averesch
- Department
of Civil and Environmental Engineering, Stanford University, Stanford, California 94305, United States
| | | | - Felix Moser
- Synlife, One Kendall Square, Cambridge, Massachusetts 02139-1661, United States
| | - John I. Glass
- J.
Craig
Venter Institute, La Jolla, California 92037, United States
| | - Rolando Cruz Perez
- Department
of Bioengineering, Stanford University, Stanford, California 94305, United States
- Blue
Marble
Space Institute of Science at NASA Ames Research Center, Moffett Field, California 94035-1000, United
States
| | - Ibrahim O. Yekinni
- Department
of Biomedical Engineering, University of
Minnesota, Minneapolis, Minnesota 55455, United States
| | - Brooke Rothschild-Mancinelli
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332-0150, United States
| | | | - Feilun Wu
- J. Craig
Venter Institute, Rockville, Maryland 20850, United States
| | - Jorik Waeterschoot
- Mechatronics,
Biostatistics and Sensors (MeBioS), KU Leuven, 3000 Leuven Belgium
| | - Ion A. Ioannou
- Department
of Chemistry, MSRH, Imperial College London, London W12 0BZ, U.K.
| | - Michael C. Jewett
- Department
of Bioengineering, Stanford University, Stanford, California 94305, United States
| | - Allen P. Liu
- Mechanical
Engineering & Biomedical Engineering, Cellular and Molecular Biology,
Biophysics, Applied Physics, University
of Michigan, Ann Arbor, Michigan 48109, United States
| | - Vincent Noireaux
- Physics
and Nanotechnology, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Carlise Sorenson
- Department
of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Katarzyna P. Adamala
- Department
of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, Minnesota 55455, United States
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2
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Piorino F, Patterson AT, Han Y, Styczynski MP. Plasmid Crosstalk in Cell-Free Expression Systems. ACS Synth Biol 2023; 12:2843-2856. [PMID: 37756020 PMCID: PMC10594874 DOI: 10.1021/acssynbio.3c00412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Indexed: 09/28/2023]
Abstract
Although cell-free protein expression has been widely used for the synthesis of single proteins, cell-free synthetic biology has rapidly expanded to new, more complex applications. One such application is the prototyping or implementation of complex genetic networks involving the expression of multiple proteins at precise ratios, often from different plasmids. However, expression of multiple proteins from multiple plasmids may inadvertently result in unexpected, off-target changes to the levels of the proteins being expressed, a phenomenon termed plasmid crosstalk. Here, we show that the effects of plasmid crosstalk─even at the qualitative level of increases vs decreases in protein expression─depend on the concentration of plasmids in the reaction and the type of transcriptional machinery involved in the expression. This crosstalk can have a significant impact on genetic circuitry function and even interpretation of simple experimental results and thus should be taken into consideration during the development of cell-free applications.
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Affiliation(s)
- Fernanda Piorino
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Alexandra T. Patterson
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Yue Han
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
| | - Mark P. Styczynski
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive NW, Atlanta, Georgia 30332-0100, United States
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3
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Bartelds MW, García-Blay Ó, Verhagen PGA, Wubbolts EJ, van Sluijs B, Heus HA, de Greef TFA, Huck WTS, Hansen MMK. Noise Minimization in Cell-Free Gene Expression. ACS Synth Biol 2023; 12:2217-2225. [PMID: 37478000 PMCID: PMC10443034 DOI: 10.1021/acssynbio.3c00174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Indexed: 07/23/2023]
Abstract
Biochemical reactions that involve small numbers of molecules are accompanied by a degree of inherent randomness that results in noisy reaction outcomes. In synthetic biology, the ability to minimize noise particularly during the reconstitution of future synthetic protocells is an outstanding challenge to secure robust and reproducible behavior. Here we show that by encapsulation of a bacterial cell-free gene expression system in water-in-oil droplets, in vitro-synthesized MazF reduces cell-free gene expression noise >2-fold. With stochastic simulations we identify that this noise minimization acts through both increased degradation and the autoregulatory feedback of MazF. Specifically, we find that the expression of MazF enhances the degradation rate of mRNA up to 18-fold in a sequence-dependent manner. This sequence specificity of MazF would allow targeted noise control, making it ideal to integrate into synthetic gene networks. Therefore, including MazF production in synthetic biology can significantly minimize gene expression noise, impacting future design principles of more complex cell-free gene circuits.
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Affiliation(s)
- Mart W. Bartelds
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Óscar García-Blay
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Pieter G. A. Verhagen
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Elise J. Wubbolts
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Bob van Sluijs
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Hans A. Heus
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Tom F. A. de Greef
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
- Laboratory
of Chemical Biology, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Institute
for Complex Molecular Systems, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Computational
Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology,
P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Center
for Living Technologies, Eindhoven-Wageningen-Utrecht
Alliance, 5600 MB Eindhoven, The Netherlands
| | - Wilhelm T. S. Huck
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| | - Maike M. K. Hansen
- Institute
for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
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4
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Lang X, Huang Y, He L, Wang Y, Thumu U, Chu Z, Huck WTS, Zhao H. Mechanosensitive non-equilibrium supramolecular polymerization in closed chemical systems. Nat Commun 2023; 14:3084. [PMID: 37248275 DOI: 10.1038/s41467-023-38948-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 05/23/2023] [Indexed: 05/31/2023] Open
Abstract
Chemical fuel-driven supramolecular systems have been developed showing out-of-equilibrium functions such as transient gelation and oscillations. However, these systems suffer from undesired waste accumulation and they function only in open systems. Herein, we report non-equilibrium supramolecular polymerizations in a closed system, which is built by viologens and pyranine in the presence of hydrazine hydrate. On shaking, the viologens are quickly oxidated by air followed by self-assembly of pyranine into micrometer-sized nanotubes. The self-assembled nanotubes disassemble spontaneously over time by the reduced agent, with nitrogen as the only waste product. Our mechanosensitive dissipative system can be extended to fabricate a chiral transient supramolecular helix by introducing chiral-charged small molecules. Moreover, we show that shaking induces transient fluorescence enhancement or quenching depending on substitution of viologens. Ultrasound is introduced as a specific shaking way to generate template-free reproducible patterns. Additionally, the shake-driven transient polymerization of amphiphilic naphthalenetetracarboxylic diimide serves as further evidence of the versatility of our mechanosensitive non-equilibrium system.
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Affiliation(s)
- Xianhua Lang
- School of Chemical Engineering, State Key Lab of Polymer Materials Engineering, Sichuan University, 610065, Chengdu, China
| | - Yingjie Huang
- School of Chemical Engineering, State Key Lab of Polymer Materials Engineering, Sichuan University, 610065, Chengdu, China
| | - Lirong He
- School of Chemical Engineering, State Key Lab of Polymer Materials Engineering, Sichuan University, 610065, Chengdu, China
| | - Yixi Wang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, 610054, Chengdu, China
| | - Udayabhaskararao Thumu
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, 610054, Chengdu, China
| | - Zonglin Chu
- College of Chemistry and Chemical Engineering, Hunan University, 410082, Changsha, China
| | - Wilhelm T S Huck
- Institute for Molecules and Materials, Radboud University, Nijmegen, The Netherlands
| | - Hui Zhao
- School of Chemical Engineering, State Key Lab of Polymer Materials Engineering, Sichuan University, 610065, Chengdu, China.
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5
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Wagner L, Jules M, Borkowski O. What remains from living cells in bacterial lysate-based cell-free systems. Comput Struct Biotechnol J 2023; 21:3173-3182. [PMID: 37333859 PMCID: PMC10275740 DOI: 10.1016/j.csbj.2023.05.025] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 05/23/2023] [Accepted: 05/23/2023] [Indexed: 06/20/2023] Open
Abstract
Because they mimic cells while offering an accessible and controllable environment, lysate-based cell-free systems (CFS) have emerged as valuable biotechnology tools for synthetic biology. Historically used to uncover fundamental mechanisms of life, CFS are nowadays used for a multitude of purposes, including protein production and prototyping of synthetic circuits. Despite the conservation of fundamental functions in CFS like transcription and translation, RNAs and certain membrane-embedded or membrane-bound proteins of the host cell are lost when preparing the lysate. As a result, CFS largely lack some essential properties of living cells, such as the ability to adapt to changing conditions, to maintain homeostasis and spatial organization. Regardless of the application, shedding light on the black-box of the bacterial lysate is necessary to fully exploit the potential of CFS. Most measurements of the activity of synthetic circuits in CFS and in vivo show significant correlations because these only require processes that are preserved in CFS, like transcription and translation. However, prototyping circuits of higher complexity that require functions that are lost in CFS (cell adaptation, homeostasis, spatial organization) will not show such a good correlation with in vivo conditions. Both for prototyping circuits of higher complexity and for building artificial cells, the cell-free community has developed devices to reconstruct cellular functions. This mini-review compares bacterial CFS to living cells, focusing on functional and cellular process differences and the latest developments in restoring lost functions through complementation of the lysate or device engineering.
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6
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Ramesh V, Suwanmajo T, Krishnan J. Network regulation meets substrate modification chemistry. J R Soc Interface 2023; 20:20220510. [PMID: 36722169 PMCID: PMC9890324 DOI: 10.1098/rsif.2022.0510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Biochemical networks are at the heart of cellular information processing. These networks contain distinct facets: (i) processing of information from the environment via cascades/pathways along with network regulation and (ii) modification of substrates in different ways, to confer protein functionality, stability and processing. While many studies focus on these factors individually, how they interact and the consequences for cellular systems behaviour are poorly understood. We develop a systems framework for this purpose by examining the interplay of network regulation (canonical feedback and feed-forward circuits) and multisite modification, as an exemplar of substrate modification. Using computational, analytical and semi-analytical approaches, we reveal distinct and unexpected ways in which the substrate modification and network levels combine and the emergent behaviour arising therefrom. This has important consequences for dissecting the behaviour of specific signalling networks, tracing the origins of systems behaviour, inference of networks from data, robustness/evolvability and multi-level engineering of biomolecular networks. Overall, we repeatedly demonstrate how focusing on only one level (say network regulation) can lead to profoundly misleading conclusions about all these aspects, and reveal a number of important consequences for experimental/theoretical/data-driven interrogations of cellular signalling systems.
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Affiliation(s)
- Vaidhiswaran Ramesh
- Department of Chemical Engineering, Sargent Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, UK
| | - Thapanar Suwanmajo
- Department of Chemical Engineering, Sargent Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, UK,Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand,Center of Excellence in Materials Science and Technology, Chiang Mai University, Chiang Mai 50200, Thailand
| | - J. Krishnan
- Department of Chemical Engineering, Sargent Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, UK,Institute for Systems and Synthetic Biology, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
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7
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Jäkel AC, Aufinger L, Simmel FC. Steady-State Operation of a Cell-Free Genetic Band-Detection Circuit. ACS Synth Biol 2022; 11:3273-3284. [PMID: 36095299 DOI: 10.1021/acssynbio.2c00195] [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: 01/24/2023]
Abstract
Pattern formation processes play a decisive role during embryogenesis and involve the precise spatial and temporal orchestration of intricate gene regulatory processes. Synthetic gene circuits modeled after their biological counterparts can be used to investigate such processes under well-controlled conditions and may, in the future, be utilized for autonomous position determination in synthetic biological materials. Here, we investigated a three-node feed-forward gene regulatory circuit in vitro that generates three distinct fluorescent outputs in response to varying concentrations of a single externally supplied morphogen. The circuit acts as a band detector for the morphogen concentration and, in a spatial context, could serve as a stripe-forming gene circuit. We simulated the behavior of the genetic circuit in the presence of a morphogen gradient using a system of ordinary differential equations and determined optimal parameters for stripe-pattern formation using an evolutionary algorithm. To analyze the subcircuits of the system, we conducted cell-free characterization experiments and finally tested the whole genetic circuit in nanoliter-scale microfluidic flow reactors that provided a continuous supply of cell extract and metabolites and allowed removal of degradation products. To make use of the widely employed promoters PLlacO-1 and PLtetO-1 in our design, we removed LacI from our bacterial cell extract by genome engineering Escherichia coli using a pORTMAGE workflow. Our results show that the band-detector works as designed when operated out of equilibrium within the flow reactors. On the other hand, subcircuits of the system and the whole circuit fail to generate the desired gene expression response when operated in a closed reactor. Our work thus underlines the importance of out-of-equilibrium operation of complex gene circuits, which cannot settle to a steady-state expression pattern within the finite lifetime of a cell-free expression system.
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Affiliation(s)
- Anna C Jäkel
- Department of Bioscience, School of Natural Sciences, Technical University of Munich, Garching D-85748, Germany
| | - Lukas Aufinger
- Department of Bioscience, School of Natural Sciences, Technical University of Munich, Garching D-85748, Germany
| | - Friedrich C Simmel
- Department of Bioscience, School of Natural Sciences, Technical University of Munich, Garching D-85748, Germany
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8
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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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9
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Aufinger L, Brenner J, Simmel FC. Complex dynamics in a synchronized cell-free genetic clock. Nat Commun 2022; 13:2852. [PMID: 35606356 PMCID: PMC9126873 DOI: 10.1038/s41467-022-30478-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 05/04/2022] [Indexed: 11/10/2022] Open
Abstract
Complex dynamics such as period doubling and chaos occur in a wide variety of non-linear dynamical systems. In the context of biological circadian clocks, such phenomena have been previously found in computational models, but their experimental study in biological systems has been challenging. Here, we present experimental evidence of period doubling in a forced cell-free genetic oscillator operated in a microfluidic reactor, where the system is periodically perturbed by modulating the concentration of one of the oscillator components. When the external driving matches the intrinsic period, we experimentally find period doubling and quadrupling in the oscillator dynamics. Our results closely match the predictions of a theoretical model, which also suggests conditions under which our system would display chaotic dynamics. We show that detuning of the external and intrinsic period leads to more stable entrainment, suggesting a simple design principle for synchronized synthetic and natural genetic clocks. In theory, driven biological oscillators can display complex dynamic behaviors, but these are experimentally difficult to observe. Here the authors, using microfluidics, show that a synthetic cell-free gene oscillator displays period doubling and even quadrupling.
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10
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Schnitter F, Rieß B, Jandl C, Boekhoven J. Memory, switches, and an OR-port through bistability in chemically fueled crystals. Nat Commun 2022; 13:2816. [PMID: 35595758 PMCID: PMC9122941 DOI: 10.1038/s41467-022-30424-2] [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: 01/17/2022] [Accepted: 04/29/2022] [Indexed: 11/12/2022] Open
Abstract
The ability to store information in chemical reaction networks is essential for the complex behavior we associate with life. In biology, cellular memory is regulated through transcriptional states that are bistable, i.e., a state that can either be on or off and can be flipped from one to another through a transient signal. Such memory circuits have been realized synthetically through the rewiring of genetic systems in vivo or through the rational design of reaction networks based on DNA and highly evolved enzymes in vitro. Completely bottom-up analogs based on small molecules are rare and hard to design and thus represent a challenge for systems chemistry. In this work, we show that bistability can be designed from a simple non-equilibrium reaction cycle that is coupled to crystallization. The crystals exert the necessary feedback on the reaction cycle required for the bistability resulting in an on-state with assemblies and an off-state without. Each state represents volatile memory that can be stored in continuously stirred tank reactors indefinitely even though molecules are turned over on a minute-timescale. We showcase the system’s abilities by creating a matrix display that can store images and by creating an OR-gate by coupling several switches together. In biology, information is stored and processed using highly evolved molecules in bistable states. Here, the authors demonstrate bistability in a synthetic system without the need for evolved biomolecules or autocatalytic networks.
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Affiliation(s)
- Fabian Schnitter
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Benedikt Rieß
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Christian Jandl
- Catalysis Research Centre, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Job Boekhoven
- Department of Chemistry, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany. .,Institute for Advanced Study, Technical University of Munich, Lichtenbergstrasse 2a, 85748, Garching, Germany.
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11
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van der Linden AJ, Pieters PA, Bartelds MW, Nathalia BL, Yin P, Huck WTS, Kim J, de Greef TFA. DNA Input Classification by a Riboregulator-Based Cell-Free Perceptron. ACS Synth Biol 2022; 11:1510-1520. [PMID: 35381174 PMCID: PMC9016768 DOI: 10.1021/acssynbio.1c00596] [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
The ability to recognize molecular patterns is essential for the continued survival of biological organisms, allowing them to sense and respond to their immediate environment. The design of synthetic gene-based classifiers has been explored previously; however, prior strategies have focused primarily on DNA strand-displacement reactions. Here, we present a synthetic in vitro transcription and translation (TXTL)-based perceptron consisting of a weighted sum operation (WSO) coupled to a downstream thresholding function. We demonstrate the application of toehold switch riboregulators to construct a TXTL-based WSO circuit that converts DNA inputs into a GFP output, the concentration of which correlates to the input pattern and the corresponding weights. We exploit the modular nature of the WSO circuit by changing the output protein to the Escherichia coli σ28-factor, facilitating the coupling of the WSO output to a downstream reporter network. The subsequent introduction of a σ28 inhibitor enabled thresholding of the WSO output such that the expression of the downstream reporter protein occurs only when the produced σ28 exceeds this threshold. In this manner, we demonstrate a genetically implemented perceptron capable of binary classification, i.e., the expression of a single output protein only when the desired minimum number of inputs is exceeded.
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Affiliation(s)
- Ardjan J. van der Linden
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Pascal A. Pieters
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Mart W. Bartelds
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Bryan L. Nathalia
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Peng Yin
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
| | - Wilhelm T. S. Huck
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
| | - Jongmin Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Tom F. A. de Greef
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Institute for Molecules and Materials, Radboud University, 6525 AJ Nijmegen, The Netherlands
- Center for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, 3584 CB Utrecht, The Netherlands
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12
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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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13
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McSweeney MA, Styczynski MP. Effective Use of Linear DNA in Cell-Free Expression Systems. Front Bioeng Biotechnol 2021; 9:715328. [PMID: 34354989 PMCID: PMC8329657 DOI: 10.3389/fbioe.2021.715328] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/06/2021] [Indexed: 12/27/2022] Open
Abstract
Cell-free expression systems (CFEs) are cutting-edge research tools used in the investigation of biological phenomena and the engineering of novel biotechnologies. While CFEs have many benefits over in vivo protein synthesis, one particularly significant advantage is that CFEs allow for gene expression from both plasmid DNA and linear expression templates (LETs). This is an important and impactful advantage because functional LETs can be efficiently synthesized in vitro in a few hours without transformation and cloning, thus expediting genetic circuit prototyping and allowing expression of toxic genes that would be difficult to clone through standard approaches. However, native nucleases present in the crude bacterial lysate (the basis for the most affordable form of CFEs) quickly degrade LETs and limit expression yield. Motivated by the significant benefits of using LETs in lieu of plasmid templates, numerous methods to enhance their stability in lysate-based CFEs have been developed. This review describes approaches to LET stabilization used in CFEs, summarizes the advancements that have come from using LETs with these methods, and identifies future applications and development goals that are likely to be impactful to the field. Collectively, continued improvement of LET-based expression and other linear DNA tools in CFEs will help drive scientific discovery and enable a wide range of applications, from diagnostics to synthetic biology research tools.
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Affiliation(s)
- Megan A McSweeney
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, GA, United States
| | - Mark P Styczynski
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, GA, United States
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14
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Pieters PA, Nathalia BL, van der Linden AJ, Yin P, Kim J, Huck WTS, de Greef TFA. Cell-Free Characterization of Coherent Feed-Forward Loop-Based Synthetic Genetic Circuits. ACS Synth Biol 2021; 10:1406-1416. [PMID: 34061505 PMCID: PMC8218305 DOI: 10.1021/acssynbio.1c00024] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Regulatory pathways
inside living cells employ feed-forward architectures
to fulfill essential signal processing functions that aid in the interpretation
of various types of inputs through noise-filtering, fold-change detection
and adaptation. Although it has been demonstrated computationally
that a coherent feed-forward loop (CFFL) can function as noise filter,
a property essential to decoding complex temporal signals, this motif
has not been extensively characterized experimentally or integrated
into larger networks. Here we use post-transcriptional regulation
to implement and characterize a synthetic CFFL in an Escherichia
coli cell-free transcription-translation system and build
larger composite feed-forward architectures. We employ microfluidic
flow reactors to probe the response of the CFFL circuit using both
persistent and short, noise-like inputs and analyze the influence
of different circuit components on the steady-state and dynamics of
the output. We demonstrate that our synthetic CFFL implementation
can reliably repress background activity compared to a reference circuit,
but displays low potential as a temporal filter, and validate these
findings using a computational model. Our results offer practical
insight into the putative noise-filtering behavior of CFFLs and show
that this motif can be used to mitigate leakage and increase the fold-change
of the output of synthetic genetic circuits.
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Affiliation(s)
- Pascal A. Pieters
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Bryan L. Nathalia
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Ardjan J. van der Linden
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
| | - Peng Yin
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - Jongmin Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Wilhelm T. S. Huck
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Tom F. A. de Greef
- Laboratory of Chemical Biology and Institute for Complex Molecular Systems, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Computational Biology Group, Department of Biomedical Engineering, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Institute for Molecules and Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
- Center for Living Technologies, Eindhoven-Wageningen-Utrecht Alliance, Eindhoven, The Netherlands
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15
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Ouyang X, Zhou X, Lai SN, Liu Q, Zheng B. Immobilization of Proteins of Cell Extract to Hydrogel Networks Enhances the Longevity of Cell-Free Protein Synthesis and Supports Gene Networks. ACS Synth Biol 2021; 10:749-755. [PMID: 33784075 DOI: 10.1021/acssynbio.0c00541] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Herein, we constructed a new type of hydrogel based artificial cells supporting long-lived protein synthesis, post-translational modification, and gene networks. We constructed the artificial cells by immobilizing the transcription and translation system from E. coli cytoplasmic extract onto the polyacrylamide hydrogel. With the continuous supply of energy and nutrition, the artificial cells were capable of stable protein expression for at least 30 days. Functional proteins which were difficult to produce in vivo, including colicin E1 and urokinase, were synthesized in the artificial cells with high bioactivity. Furthermore, we constructed a sigma factor based genetic oscillator in the artificial cells. The artificial cells not only provide a powerful platform for continuous protein synthesis and convenient design and testing of genetic networks, but also hold great promise for the development of metabolic engineering, drug delivery, and biosensors.
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Affiliation(s)
- Xiaofei Ouyang
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Xiaoyu Zhou
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Sze Nga Lai
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Qi Liu
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
| | - Bo Zheng
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, Hong Kong
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16
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Batista AC, Soudier P, Kushwaha M, Faulon J. Optimising protein synthesis in cell‐free systems, a review. ENGINEERING BIOLOGY 2021; 5:10-19. [PMID: 36968650 PMCID: PMC9996726 DOI: 10.1049/enb2.12004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 12/03/2020] [Accepted: 12/09/2020] [Indexed: 12/25/2022] Open
Abstract
Over the last decades, cell-free systems have been extensively used for in vitro protein expression. A vast range of protocols and cellular sources varying from prokaryotes and eukaryotes are now available for cell-free technology. However, exploiting the maximum capacity of cell free systems is not achieved by using traditional protocols. Here, what are the strategies and choices one can apply to optimise cell-free protein synthesis have been reviewed. These strategies provide robust and informative improvements regarding transcription, translation and protein folding which can later be used for the establishment of individual best cell-free reactions per lysate batch.
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Affiliation(s)
- Angelo C. Batista
- Université Paris‐Saclay INRAE AgroParisTech Micalis Institute Jouy‐en‐Josas France
| | - Paul Soudier
- Université Paris‐Saclay INRAE AgroParisTech Micalis Institute Jouy‐en‐Josas France
| | - Manish Kushwaha
- Université Paris‐Saclay INRAE AgroParisTech Micalis Institute Jouy‐en‐Josas France
| | - Jean‐Loup Faulon
- Université Paris‐Saclay INRAE AgroParisTech Micalis Institute Jouy‐en‐Josas France
- SYNBIOCHEM Center School of Chemistry Manchester Institute of Biotechnology The University of Manchester Manchester UK
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17
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Adhikari A, Vilkhovoy M, Vadhin S, Lim HE, Varner JD. Effective Biophysical Modeling of Cell Free Transcription and Translation Processes. Front Bioeng Biotechnol 2020; 8:539081. [PMID: 33324619 PMCID: PMC7726328 DOI: 10.3389/fbioe.2020.539081] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 11/02/2020] [Indexed: 12/18/2022] Open
Abstract
Transcription and translation are at the heart of metabolism and signal transduction. In this study, we developed an effective biophysical modeling approach to simulate transcription and translation processes. The model, composed of coupled ordinary differential equations, was tested by comparing simulations of two cell free synthetic circuits with experimental measurements generated in this study. First, we considered a simple circuit in which sigma factor 70 induced the expression of green fluorescent protein. This relatively simple case was then followed by a more complex negative feedback circuit in which two control genes were coupled to the expression of a third reporter gene, green fluorescent protein. Many of the model parameters were estimated from previous biophysical studies in the literature, while the remaining unknown model parameters for each circuit were estimated by minimizing the difference between model simulations and messenger RNA (mRNA) and protein measurements generated in this study. In particular, either parameter estimates from published studies were used directly, or characteristic values found in the literature were used to establish feasible ranges for the parameter estimation problem. In order to perform a detailed analysis of the influence of individual model parameters on the expression dynamics of each circuit, global sensitivity analysis was used. Taken together, the effective biophysical modeling approach captured the expression dynamics, including the transcription dynamics, for the two synthetic cell free circuits. While, we considered only two circuits here, this approach could potentially be extended to simulate other genetic circuits in both cell free and whole cell biomolecular applications as the equations governing the regulatory control functions are modular and easily modifiable. The model code, parameters, and analysis scripts are available for download under an MIT software license from the Varnerlab GitHub repository.
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Affiliation(s)
- Abhinav Adhikari
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, College of Engineering, Cornell University, Ithaca, NY, United States
| | - Michael Vilkhovoy
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, College of Engineering, Cornell University, Ithaca, NY, United States
| | - Sandra Vadhin
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, College of Engineering, Cornell University, Ithaca, NY, United States
| | - Ha Eun Lim
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, College of Engineering, Cornell University, Ithaca, NY, United States
| | - Jeffrey D Varner
- Robert Frederick Smith School of Chemical and Biomolecular Engineering, College of Engineering, Cornell University, Ithaca, NY, United States
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18
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Miller TE, Beneyton T, Schwander T, Diehl C, Girault M, McLean R, Chotel T, Claus P, Cortina NS, Baret JC, Erb TJ. Light-powered CO 2 fixation in a chloroplast mimic with natural and synthetic parts. Science 2020; 368:649-654. [PMID: 32381722 DOI: 10.1126/science.aaz6802] [Citation(s) in RCA: 164] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 03/24/2020] [Indexed: 12/21/2022]
Abstract
Nature integrates complex biosynthetic and energy-converting tasks within compartments such as chloroplasts and mitochondria. Chloroplasts convert light into chemical energy, driving carbon dioxide fixation. We used microfluidics to develop a chloroplast mimic by encapsulating and operating photosynthetic membranes in cell-sized droplets. These droplets can be energized by light to power enzymes or enzyme cascades and analyzed for their catalytic properties in multiplex and real time. We demonstrate how these microdroplets can be programmed and controlled by adjusting internal compositions and by using light as an external trigger. We showcase the capability of our platform by integrating the crotonyl-coenzyme A (CoA)/ethylmalonyl-CoA/hydroxybutyryl-CoA (CETCH) cycle, a synthetic network for carbon dioxide conversion, to create an artificial photosynthetic system that interfaces the natural and the synthetic biological worlds.
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Affiliation(s)
- Tarryn E Miller
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Thomas Beneyton
- University of Bordeaux, CNRS, Centre de Recherche Paul Pascal, UMR 5031, Pessac 33600, France
| | - Thomas Schwander
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Christoph Diehl
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | | | - Richard McLean
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Tanguy Chotel
- University of Bordeaux, CNRS, Centre de Recherche Paul Pascal, UMR 5031, Pessac 33600, France
| | - Peter Claus
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Niña Socorro Cortina
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
| | - Jean-Christophe Baret
- University of Bordeaux, CNRS, Centre de Recherche Paul Pascal, UMR 5031, Pessac 33600, France. .,Institut Universitaire de France, Paris 75005, France
| | - Tobias J Erb
- Department of Biochemistry and Synthetic Metabolism, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany. .,Center for Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, D-35043 Marburg, Germany
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19
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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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20
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Prangemeier T, Lehr FX, Schoeman RM, Koeppl H. Microfluidic platforms for the dynamic characterisation of synthetic circuitry. Curr Opin Biotechnol 2020; 63:167-176. [PMID: 32172160 DOI: 10.1016/j.copbio.2020.02.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/31/2020] [Accepted: 02/03/2020] [Indexed: 01/28/2023]
Abstract
Generating novel functionality from well characterised synthetic parts and modules lies at the heart of synthetic biology. Ideally, circuitry is rationally designed in silico with quantitatively predictive models to predetermined design specifications. Synthetic circuits are intrinsically stochastic, often dynamically modulated and set in a dynamic fluctuating environment within a living cell. To build more complex circuits and to gain insight into context effects, intrinsic noise and transient performance, characterisation techniques that resolve both heterogeneity and dynamics are required. Here we review recent advances in both in vitro and in vivo microfluidic technologies that are suitable for the characterisation of synthetic circuitry, modules and parts.
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Affiliation(s)
- Tim Prangemeier
- Centre for Synthetic Biology, Department of Electrical Engineering and Information Technology, Department of Biology, Technische Universität Darmstadt, Germany
| | - François-Xavier Lehr
- Centre for Synthetic Biology, Department of Electrical Engineering and Information Technology, Department of Biology, Technische Universität Darmstadt, Germany
| | - Rogier M Schoeman
- Centre for Synthetic Biology, Department of Electrical Engineering and Information Technology, Department of Biology, Technische Universität Darmstadt, Germany
| | - Heinz Koeppl
- Centre for Synthetic Biology, Department of Electrical Engineering and Information Technology, Department of Biology, Technische Universität Darmstadt, Germany.
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21
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Abstract
Liquid-liquid phase separation plays an important role in cellular organization. Many subcellular condensed bodies are hierarchically organized into multiple coexisting domains or layers. However, our molecular understanding of the assembly and internal organization of these multicomponent droplets is still incomplete, and rules for the coexistence of condensed phases are lacking. Here, we show that the formation of hierarchically organized multiphase droplets with up to three coexisting layers is a generic phenomenon in mixtures of complex coacervates, which serve as models of charge-driven liquid-liquid phase separated systems. We present simple theoretical guidelines to explain both the hierarchical arrangement and the demixing transition in multiphase droplets using the interfacial tensions and critical salt concentration as inputs. Multiple coacervates can coexist if they differ sufficiently in macromolecular density, and we show that the associated differences in critical salt concentration can be used to predict multiphase droplet formation. We also show that the coexisting coacervates present distinct chemical environments that can concentrate guest molecules to different extents. Our findings suggest that condensate immiscibility may be a very general feature in biological systems, which could be exploited to design self-organized synthetic compartments to control biomolecular processes.
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Affiliation(s)
- Tiemei Lu
- Institute for Molecules and
Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
| | - Evan Spruijt
- Institute for Molecules and
Materials, Radboud University, Heyendaalseweg 135, 6525 AJ, Nijmegen, The Netherlands
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22
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Ayoubi-Joshaghani MH, Dianat-Moghadam H, Seidi K, Jahanban-Esfahalan A, Zare P, Jahanban-Esfahlan R. Cell-free protein synthesis: The transition from batch reactions to minimal cells and microfluidic devices. Biotechnol Bioeng 2020; 117:1204-1229. [PMID: 31840797 DOI: 10.1002/bit.27248] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 11/23/2019] [Accepted: 12/09/2019] [Indexed: 12/13/2022]
Abstract
Thanks to the synthetic biology, the laborious and restrictive procedure for producing a target protein in living microorganisms by biotechnological approaches can now experience a robust, pliant yet efficient alternative. The new system combined with lab-on-chip microfluidic devices and nanotechnology offers a tremendous potential envisioning novel cell-free formats such as DNA brushes, hydrogels, vesicular particles, droplets, as well as solid surfaces. Acting as robust microreactors/microcompartments/minimal cells, the new platforms can be tuned to perform various tasks in a parallel and integrated manner encompassing gene expression, protein synthesis, purification, detection, and finally enabling cell-cell signaling to bring a collective cell behavior, such as directing differentiation process, characteristics of higher order entities, and beyond. In this review, we issue an update on recent cell-free protein synthesis (CFPS) formats. Furthermore, the latest advances and applications of CFPS for synthetic biology and biotechnology are highlighted. In the end, contemporary challenges and future opportunities of CFPS systems are discussed.
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Affiliation(s)
| | | | - Khaled Seidi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Peyman Zare
- Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland
| | - Rana Jahanban-Esfahlan
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
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23
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Aufinger L, Simmel FC. Establishing Communication Between Artificial Cells. Chemistry 2019; 25:12659-12670. [DOI: 10.1002/chem.201901726] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 06/23/2019] [Indexed: 12/25/2022]
Affiliation(s)
- Lukas Aufinger
- Physics Department and ZNNTechnische Universität München Am Coulombwall 4a 85748 Garching Germany
| | - Friedrich C. Simmel
- Physics Department and ZNNTechnische Universität München Am Coulombwall 4a 85748 Garching Germany
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24
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Eilenberger C, Spitz S, Bachmann BEM, Ehmoser EK, Ertl P, Rothbauer M. The Usual Suspects 2019: of Chips, Droplets, Synthesis, and Artificial Cells. MICROMACHINES 2019; 10:E285. [PMID: 31035574 PMCID: PMC6562886 DOI: 10.3390/mi10050285] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 04/24/2019] [Accepted: 04/26/2019] [Indexed: 12/03/2022]
Abstract
Synthetic biology aims to understand fundamental biological processes in more detail than possible for actual living cells. Synthetic biology can combat decomposition and build-up of artificial experimental models under precisely controlled and defined environmental and biochemical conditions. Microfluidic systems can provide the tools to improve and refine existing synthetic systems because they allow control and manipulation of liquids on a micro- and nanoscale. In addition, chip-based approaches are predisposed for synthetic biology applications since they present an opportune technological toolkit capable of fully automated high throughput and content screening under low reagent consumption. This review critically highlights the latest updates in microfluidic cell-free and cell-based protein synthesis as well as the progress on chip-based artificial cells. Even though progress is slow for microfluidic synthetic biology, microfluidic systems are valuable tools for synthetic biology and may one day help to give answers to long asked questions of fundamental cell biology and life itself.
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Affiliation(s)
- Christoph Eilenberger
- Institute of Applied Synthetic Chemistry, Institute of Chemical Technologies and Analytics, Faculty of Technical Chemistry, Vienna University of Technology, A-1060 Vienna, Austria.
| | - Sarah Spitz
- Institute of Applied Synthetic Chemistry, Institute of Chemical Technologies and Analytics, Faculty of Technical Chemistry, Vienna University of Technology, A-1060 Vienna, Austria.
| | - Barbara Eva Maria Bachmann
- Austrian Cluster for Tissue Regeneration, Vienna, Austria; Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Allgemeine Unfallversicherungsanstalt (AUVA) Research Centre, A-1200 Vienna, Austria.
| | - Eva Kathrin Ehmoser
- Institute of Synthetic Bioarchitectures, Department of Nanobiotechnology, University of Natural Resources and Life Sciences Vienna, A-1190 Vienna, Austria.
| | - Peter Ertl
- Institute of Applied Synthetic Chemistry, Institute of Chemical Technologies and Analytics, Faculty of Technical Chemistry, Vienna University of Technology, A-1060 Vienna, Austria.
| | - Mario Rothbauer
- Institute of Applied Synthetic Chemistry, Institute of Chemical Technologies and Analytics, Faculty of Technical Chemistry, Vienna University of Technology, A-1060 Vienna, Austria.
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25
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Guo S, Murray RM. Construction of Incoherent Feedforward Loop Circuits in a Cell-Free System and in Cells. ACS Synth Biol 2019; 8:606-610. [PMID: 30790525 DOI: 10.1021/acssynbio.8b00493] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Cells utilize transcriptional regulation networks to respond to environmental signals. Network motifs, such as feedforward loops, play essential roles in these regulatory networks. In this work, we construct two different functional and modular incoherent type 1 feedforward loop circuits in a cell-free transcription-translation system and in cells. With the help of mathematical modeling and the cell-free system, we can streamline the design-build-test cycles of the circuits, in which we characterize and optimize these circuits in vitro to confirm that they function as expected before implementing them in vivo. We show that the performance of these circuits from in vitro studies closely recapitulates those from in vivo experiments. We demonstrate that these feedforward loops show dynamic response and pulse-like behavior both in vitro and in vivo. These novel feedforward loop network motifs can be incorporated in more complicated biological circuits as detectors or responders.
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Affiliation(s)
- Shaobin Guo
- Department of Biochemistry and Molecular Biophysics, California Institute of Technology, Pasadena, California 91125, United States
| | - Richard M. Murray
- Department of Biochemistry and Molecular Biophysics, California Institute of Technology, Pasadena, California 91125, United States
- Department of Control and Dynamical Systems, California Institute of Technology, Pasadena, California 91125, United States
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