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Lu Z, Shen Q, Bandari NC, Evans S, McDonnell L, Liu L, Jin W, Luna-Flores CH, Collier T, Talbo G, McCubbin T, Esquirol L, Myers C, Trau M, Dumsday G, Speight R, Howard CB, Vickers CE, Peng B. LowTempGAL: a highly responsive low temperature-inducible GAL system in Saccharomyces cerevisiae. Nucleic Acids Res 2024; 52:7367-7383. [PMID: 38808673 PMCID: PMC11229376 DOI: 10.1093/nar/gkae460] [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: 11/19/2023] [Revised: 05/12/2024] [Accepted: 05/16/2024] [Indexed: 05/30/2024] Open
Abstract
Temperature is an important control factor for biologics biomanufacturing in precision fermentation. Here, we explored a highly responsive low temperature-inducible genetic system (LowTempGAL) in the model yeast Saccharomyces cerevisiae. Two temperature biosensors, a heat-inducible degron and a heat-inducible protein aggregation domain, were used to regulate the GAL activator Gal4p, rendering the leaky LowTempGAL systems. Boolean-type induction was achieved by implementing a second-layer control through low-temperature-mediated repression on GAL repressor gene GAL80, but suffered delayed response to low-temperature triggers and a weak response at 30°C. Application potentials were validated for protein and small molecule production. Proteomics analysis suggested that residual Gal80p and Gal4p insufficiency caused suboptimal induction. 'Turbo' mechanisms were engineered through incorporating a basal Gal4p expression and a galactose-independent Gal80p-supressing Gal3p mutant (Gal3Cp). Varying Gal3Cp configurations, we deployed the LowTempGAL systems capable for a rapid stringent high-level induction upon the shift from a high temperature (37-33°C) to a low temperature (≤30°C). Overall, we present a synthetic biology procedure that leverages 'leaky' biosensors to deploy highly responsive Boolean-type genetic circuits. The key lies in optimisation of the intricate layout of the multi-factor system. The LowTempGAL systems may be applicable in non-conventional yeast platforms for precision biomanufacturing.
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Affiliation(s)
- Zeyu Lu
- ARC Centre of Excellence in Synthetic Biology, Australia
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Qianyi Shen
- ARC Centre of Excellence in Synthetic Biology, Australia
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Naga Chandra Bandari
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Samuel Evans
- ARC Centre of Excellence in Synthetic Biology, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Liam McDonnell
- ARC Centre of Excellence in Synthetic Biology, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Lian Liu
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- The Queensland Node of Metabolomics Australia and Proteomics Australia (Q-MAP), Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Wanli Jin
- Institute for Molecular Bioscience (IMB), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Carlos Horacio Luna-Flores
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Thomas Collier
- ARC Centre of Excellence in Synthetic Biology, Australia
- School of Natural Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Gert Talbo
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- The Queensland Node of Metabolomics Australia and Proteomics Australia (Q-MAP), Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Tim McCubbin
- ARC Centre of Excellence in Synthetic Biology, Australia
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Lygie Esquirol
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- Environment, Commonwealth Scientific and Industrial Research Organisation, Canberra, ACT 2601, Australia
| | - Chris Myers
- Department of Electrical, Computer, and Energy Engineering University of Colorado, Boulder, CO 80309, USA
| | - Matt Trau
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- School of Chemistry and Molecular Biosciences (SCMB), the University of Queensland, Brisbane, QLD 4072, Australia
| | - Geoff Dumsday
- Manufacturing, Commonwealth Scientific and Industrial Research Organisation, Clayton, VIC, 3169, Australia
| | - Robert Speight
- ARC Centre of Excellence in Synthetic Biology, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
- Advanced Engineering Biology Future Science Platform, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Black Mountain, ACT, 2601, Australia
| | - Christopher B Howard
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
| | - Claudia E Vickers
- ARC Centre of Excellence in Synthetic Biology, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - Bingyin Peng
- ARC Centre of Excellence in Synthetic Biology, Australia
- Australian Institute for Bioengineering and Nanotechnology (AIBN), The University of Queensland, Brisbane, QLD 4072, Australia
- Centre of Agriculture and the Bioeconomy, School of Biology and Environmental Science, Faculty of Science, Queensland University of Technology, Brisbane, QLD 4000, Australia
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2
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Jiang T, Teng Y, Li C, Gan Q, Zhang J, Zou Y, Desai BK, Yan Y. Establishing Tunable Genetic Logic Gates with Versatile Dynamic Performance by Varying Regulatory Parameters. ACS Synth Biol 2023; 12:3730-3742. [PMID: 38033235 PMCID: PMC10729296 DOI: 10.1021/acssynbio.3c00554] [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: 09/06/2023] [Revised: 10/18/2023] [Accepted: 11/13/2023] [Indexed: 12/02/2023]
Abstract
Genetic logic gates can be employed in metabolic engineering and synthetic biology to regulate gene expression based on diverse inputs. Design of tunable genetic logic gates with versatile dynamic performance is essential for expanding the usability of these toolsets. Here, using the p-coumaric acid biosensor system as a proof-of-concept, we initially investigated the parameters influencing the buffer (BUF) genetic logic gates. Subsequently, integrating binding sequences from the p-coumaric acid biosensor system and tetR or lacI regulation systems into a constitutive promoter yielded AND genetic logic gates. Additionally, characterized antisense RNAs (asRNAs) or single guide RNAs (sgRNAs) with various repression efficiencies were combined with BUF gates to construct a suite of p-coumaric acid-triggered NOT genetic logic gates. Finally, the designed BUF and NOT gates were combined to construct bifunctional genetic circuits that were subjected to orthogonality evaluation. The genetic logic gates established in this study can serve as valuable tools in future applications of metabolic engineering and synthetic biology.
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Affiliation(s)
- Tian Jiang
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Yuxi Teng
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Chenyi Li
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Qi Gan
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Jianli Zhang
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Yusong Zou
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Bhaven Kalpesh Desai
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
| | - Yajun Yan
- School
of Chemical, Materials, and Biomedical Engineering, College of Engineering, The University of Georgia, Athens, Georgia 30602, United States
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3
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Canadell D, Ortiz-Vaquerizas N, Mogas-Diez S, de Nadal E, Macia J, Posas F. Implementing re-configurable biological computation with distributed multicellular consortia. Nucleic Acids Res 2022; 50:12578-12595. [PMID: 36454021 PMCID: PMC9757037 DOI: 10.1093/nar/gkac1120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 10/30/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
The use of synthetic biological circuits to deal with numerous biological challenges has been proposed in several studies, but its implementation is still remote. A major problem encountered is the complexity of the cellular engineering needed to achieve complex biological circuits and the lack of general-purpose biological systems. The generation of re-programmable circuits can increase circuit flexibility and the scalability of complex cell-based computing devices. Here we present a new architecture to produce reprogrammable biological circuits that allow the development of a variety of different functions with minimal cell engineering. We demonstrate the feasibility of creating several circuits using only a small set of engineered cells, which can be externally reprogrammed to implement simple logics in response to specific inputs. In this regard, depending on the computation needs, a device composed of a number of defined cells can generate a variety of circuits without the need of further cell engineering or rearrangements. In addition, the inclusion of a memory module in the circuits strongly improved the digital response of the devices. The reprogrammability of biological circuits is an intrinsic capacity that is not provided in electronics and it may be used as a tool to solve complex biological problems.
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Affiliation(s)
- David Canadell
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona 08028, Spain,Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Nicolás Ortiz-Vaquerizas
- Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Barcelona 08028, Spain,Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Sira Mogas-Diez
- Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain,Synthetic Biology for Biomedical Applications Group, Department of Medicine and Life Sciences (MELIS), Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
| | - Eulàlia de Nadal
- Correspondence may also be addressed to Eulàlia de Nadal. Tel: +34 93 40 39895;
| | - Javier Macia
- Correspondence may also be addressed to Javier Macia. Tel: +34 93 316 05 39;
| | - Francesc Posas
- To whom correspondence should be addressed. Tel: +34 93 40 37110;
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4
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Recent Advances in Metal−Oxide Thin−Film Transistors: Flexible/Stretchable Devices, Integrated Circuits, Biosensors and Neuromorphic Applications. COATINGS 2022. [DOI: 10.3390/coatings12020204] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Thin−film transistors using metal oxides have been investigated extensively because of their high transparency, large area, and mass production of metal oxide semiconductors. Compatibility with conventional semiconductor processes, such as photolithography of the metal oxide offers the possibility to develop integrated circuits on a larger scale. In addition, combinations with other materials have enabled the development of sensor applications or neuromorphic devices in recent years. Here, this paper provides a timely overview of metal−oxide−based thin−film transistors focusing on emerging applications, including flexible/stretchable devices, integrated circuits, biosensors, and neuromorphic devices. This overview also revisits recent efforts on metal oxide−based thin−film transistors developed with high compatibility for integration to newly reported applications.
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5
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Robinson AO, Venero OM, Adamala KP. Toward synthetic life: Biomimetic synthetic cell communication. Curr Opin Chem Biol 2021; 64:165-173. [PMID: 34597982 PMCID: PMC8784175 DOI: 10.1016/j.cbpa.2021.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 11/25/2022]
Abstract
Engineering synthetic minimal cells provide a controllable chassis for studying the biochemical principles of natural life, increasing our understanding of complex biological processes. Recently, synthetic cell engineering has enabled communication between both natural live cells and other synthetic cells. A system such as these enable studying interactions between populations of cells, both natural and artificial, and engineering small molecule cell communication protocols for a variety of basic research and practical applications. In this review, we summarize recent progress in engineering communication between synthetic and natural cells, and we speculate about the possible future directions of this work.
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Affiliation(s)
- Abbey O Robinson
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Orion M Venero
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA
| | - Katarzyna P Adamala
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA.
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6
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Tas H, Grozinger L, Stoof R, de Lorenzo V, Goñi-Moreno Á. Contextual dependencies expand the re-usability of genetic inverters. Nat Commun 2021; 12:355. [PMID: 33441561 PMCID: PMC7806840 DOI: 10.1038/s41467-020-20656-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 12/02/2020] [Indexed: 01/29/2023] Open
Abstract
The implementation of Boolean logic circuits in cells have become a very active field within synthetic biology. Although these are mostly focussed on the genetic components alone, the context in which the circuit performs is crucial for its outcome. We characterise 20 genetic NOT logic gates in up to 7 bacterial-based contexts each, to generate 135 different functions. The contexts we focus on are combinations of four plasmid backbones and three hosts, two Escherichia coli and one Pseudomonas putida strains. Each gate shows seven different dynamic behaviours, depending on the context. That is, gates can be fine-tuned by changing only contextual parameters, thus improving the compatibility between gates. Finally, we analyse portability by measuring, scoring, and comparing gate performance across contexts. Rather than being a limitation, we argue that the effect of the genetic background on synthetic constructs expands functionality, and advocate for considering context as a fundamental design parameter.
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Affiliation(s)
- Huseyin Tas
- grid.428469.50000 0004 1794 1018Systems Biology Department, Centro Nacional de Biotecnologia-CSIC, Campus de Cantoblanco, Madrid, 28049 Spain
| | - Lewis Grozinger
- grid.1006.70000 0001 0462 7212School of Computing, Newcastle University, Newcastle Upon Tyne, NE4 5TG UK
| | - Ruud Stoof
- grid.1006.70000 0001 0462 7212School of Computing, Newcastle University, Newcastle Upon Tyne, NE4 5TG UK
| | - Victor de Lorenzo
- grid.428469.50000 0004 1794 1018Systems Biology Department, Centro Nacional de Biotecnologia-CSIC, Campus de Cantoblanco, Madrid, 28049 Spain
| | - Ángel Goñi-Moreno
- grid.1006.70000 0001 0462 7212School of Computing, Newcastle University, Newcastle Upon Tyne, NE4 5TG UK ,grid.419190.40000 0001 2300 669XCentro de Biotecnología y Genómica de Plantas (CBGP, UPM-INIA), Universidad Politénica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo-UPM, 28223 Pozuelo de Alarcón, Madrid, Spain
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7
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Kang M, Choe D, Kim K, Cho BK, Cho S. Synthetic Biology Approaches in The Development of Engineered Therapeutic Microbes. Int J Mol Sci 2020; 21:ijms21228744. [PMID: 33228099 PMCID: PMC7699352 DOI: 10.3390/ijms21228744] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/11/2020] [Accepted: 11/17/2020] [Indexed: 12/24/2022] Open
Abstract
Since the intimate relationship between microbes and human health has been uncovered, microbes have been in the spotlight as therapeutic targets for several diseases. Microbes contribute to a wide range of diseases, such as gastrointestinal disorders, diabetes and cancer. However, as host-microbiome interactions have not been fully elucidated, treatments such as probiotic administration and fecal transplantations that are used to modulate the microbial community often cause nonspecific results with serious safety concerns. As an alternative, synthetic biology can be used to rewire microbial networks such that the microbes can function as therapeutic agents. Genetic sensors can be transformed to detect biomarkers associated with disease occurrence and progression. Moreover, microbes can be reprogrammed to produce various therapeutic molecules from the host and bacterial proteins, such as cytokines, enzymes and signaling molecules, in response to a disturbed physiological state of the host. These therapeutic treatment systems are composed of several genetic parts, either identified in bacterial endogenous regulation systems or developed through synthetic design. Such genetic components are connected to form complex genetic logic circuits for sophisticated therapy. In this review, we discussed the synthetic biology strategies that can be used to construct engineered therapeutic microbes for improved microbiome-based treatment.
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Affiliation(s)
- Minjeong Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (M.K.); (D.C.); (K.K.)
| | - Donghui Choe
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (M.K.); (D.C.); (K.K.)
| | - Kangsan Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (M.K.); (D.C.); (K.K.)
| | - Byung-Kwan Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (M.K.); (D.C.); (K.K.)
- Innovative Biomaterials Research Center, KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
- Intelligent Synthetic Biology Center, Daejeon 34141, Korea
- Correspondence: (B.-K.C.); (S.C.)
| | - Suhyung Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea; (M.K.); (D.C.); (K.K.)
- Innovative Biomaterials Research Center, KI for the BioCentury, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
- Correspondence: (B.-K.C.); (S.C.)
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8
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Davey JA, Wilson CJ. Engineered signal-coupled inducible promoters: measuring the apparent RNA-polymerase resource budget. Nucleic Acids Res 2020; 48:9995-10012. [PMID: 32890400 PMCID: PMC7515704 DOI: 10.1093/nar/gkaa734] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 08/18/2020] [Accepted: 08/24/2020] [Indexed: 02/07/2023] Open
Abstract
Inducible promoters are a central regulatory component in synthetic biology, metabolic engineering, and protein production for laboratory and commercial uses. Many of these applications utilize two or more exogenous promoters, imposing a currently unquantifiable metabolic burden on the living system. Here, we engineered a collection of inducible promoters (regulated by LacI-based transcription factors) that maximize the free-state of endogenous RNA polymerase (RNAP). We leveraged this collection of inducible promotors to construct simple two-channel logical controls that enabled us to measure metabolic burden – as it relates to RNAP resource partitioning. The two-channel genetic circuits utilized sets of signal-coupled transcription factors that regulate cognate inducible promoters in a coordinated logical fashion. With this fundamental genetic architecture, we evaluated the performance of each inducible promoter as discrete operations, and as coupled systems to evaluate and quantify the effects of resource partitioning. Obtaining the ability to systematically and accurately measure the apparent RNA-polymerase resource budget will enable researchers to design more robust genetic circuits, with significantly higher fidelity. Moreover, this study presents a workflow that can be used to better understand how living systems adapt RNAP resources, via the complementary pairing of constitutive and regulated promoters that vary in strength.
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Affiliation(s)
- James A Davey
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, 311 Ferst Drive, Atlanta, GA 30332-0100, USA
| | - Corey J Wilson
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, 311 Ferst Drive, Atlanta, GA 30332-0100, USA
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9
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Stoof R, Goñi-Moreno Á. Modelling co-translational dimerization for programmable nonlinearity in synthetic biology. J R Soc Interface 2020; 17:20200561. [PMID: 33143595 DOI: 10.1098/rsif.2020.0561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Nonlinearity plays a fundamental role in the performance of both natural and synthetic biological networks. Key functional motifs in living microbial systems, such as the emergence of bistability or oscillations, rely on nonlinear molecular dynamics. Despite its core importance, the rational design of nonlinearity remains an unmet challenge. This is largely due to a lack of mathematical modelling that accounts for the mechanistic basis of nonlinearity. We introduce a model for gene regulatory circuits that explicitly simulates protein dimerization-a well-known source of nonlinear dynamics. Specifically, our approach focuses on modelling co-translational dimerization: the formation of protein dimers during-and not after-translation. This is in contrast to the prevailing assumption that dimer generation is only viable between freely diffusing monomers (i.e. post-translational dimerization). We provide a method for fine-tuning nonlinearity on demand by balancing the impact of co- versus post-translational dimerization. Furthermore, we suggest design rules, such as protein length or physical separation between genes, that may be used to adjust dimerization dynamics in vivo. The design, build and test of genetic circuits with on-demand nonlinear dynamics will greatly improve the programmability of synthetic biological systems.
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Affiliation(s)
- Ruud Stoof
- School of Computing, Newcastle University, Urban Sciences Building, Science Square, Newcastle upon Tyne NE4 5TG, UK
| | - Ángel Goñi-Moreno
- School of Computing, Newcastle University, Urban Sciences Building, Science Square, Newcastle upon Tyne NE4 5TG, UK.,Centro de Biotecnología y Genómica de Plantas (CBGP, UPM-INIA), Universidad Politénica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus de Montegancedo-UPM, 28223 Pozuelo de Alarcón, Madrid, Spain
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10
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Karkaria BD, Treloar NJ, Barnes CP, Fedorec AJH. From Microbial Communities to Distributed Computing Systems. Front Bioeng Biotechnol 2020; 8:834. [PMID: 32793576 PMCID: PMC7387671 DOI: 10.3389/fbioe.2020.00834] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Accepted: 06/29/2020] [Indexed: 12/15/2022] Open
Abstract
A distributed biological system can be defined as a system whose components are located in different subpopulations, which communicate and coordinate their actions through interpopulation messages and interactions. We see that distributed systems are pervasive in nature, performing computation across all scales, from microbial communities to a flock of birds. We often observe that information processing within communities exhibits a complexity far greater than any single organism. Synthetic biology is an area of research which aims to design and build synthetic biological machines from biological parts to perform a defined function, in a manner similar to the engineering disciplines. However, the field has reached a bottleneck in the complexity of the genetic networks that we can implement using monocultures, facing constraints from metabolic burden and genetic interference. This makes building distributed biological systems an attractive prospect for synthetic biology that would alleviate these constraints and allow us to expand the applications of our systems into areas including complex biosensing and diagnostic tools, bioprocess control and the monitoring of industrial processes. In this review we will discuss the fundamental limitations we face when engineering functionality with a monoculture, and the key areas where distributed systems can provide an advantage. We cite evidence from natural systems that support arguments in favor of distributed systems to overcome the limitations of monocultures. Following this we conduct a comprehensive overview of the synthetic communities that have been built to date, and the components that have been used. The potential computational capabilities of communities are discussed, along with some of the applications that these will be useful for. We discuss some of the challenges with building co-cultures, including the problem of competitive exclusion and maintenance of desired community composition. Finally, we assess computational frameworks currently available to aide in the design of microbial communities and identify areas where we lack the necessary tools.
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Affiliation(s)
- Behzad D. Karkaria
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Neythen J. Treloar
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Chris P. Barnes
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
- UCL Genetics Institute, University College London, London, United Kingdom
| | - Alex J. H. Fedorec
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
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11
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Soheili N, Eshghi M, Emadi-Baygi M, Mirzaei SA, Heidari R, Hosseinzadeh M. Design and evaluation of biological gate circuits and their therapeutic applications in a model of multidrug resistant cancers. Biotechnol Lett 2020; 42:1419-1429. [PMID: 32207039 DOI: 10.1007/s10529-020-02851-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 02/26/2020] [Indexed: 11/28/2022]
Abstract
OBJECTIVES Synthetic biology is primarily an emerging research field that consists of designing new synthetic gene circuits dedicated to targeted functions and therapies such as cancer therapy. In this study, a genetic logic NOT-IF gate is used to reduce the multidrug resistance and facilitate the malignant cancer therapy. MCF7 cancer cells were cultured in RPMI-1640 medium and transfected with lentiviral vectors including MDR1 gene and the corresponding shRNA against MDR1 with controllable promoters. Transcript levels and protein levels of MDR1 gene were quantified. RESULTS Our results showed that when doxycycline (DOX) and sodium butyrate were present and IPTG was absent, these led to a 74,354-fold increase in MDR1 gene expression. Upon IPTG treatment, the MDR1 gene expression was not detected due to the lack of the inducer. In addition, following IPTG induction in the presence of DOX and sodium butyrate and expressing shRNA, there was a 75% reduction in MDR1 gene expression compared to those cells treated only with sodium butyrate and DOX. CONCLUSIONS We successfully designed and implemented the genetic logic NOT-IF gate at the transcriptional level using the inducible expression of both MDR1 drug resistance pump and its specific shRNA in MCF7 cancer cells, using the third generation lentiviral vectors.
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Affiliation(s)
- Naeimeh Soheili
- Department of Computer Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad Eshghi
- Department of Computer Engineering, Faculty of Computer and Electrical Engineering, Shahid Beheshti University, Tehran, Iran.
| | - Modjtaba Emadi-Baygi
- Department of Genetics, Faculty of Basic Sciences, Shahrekord University, Shahrekord, Iran.,Research Institute of Biotechnology, Shahrekord University, Shahrekord, Iran
| | - Seyed Abbas Mirzaei
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Razieh Heidari
- Department of Medical Biotechnology, School of Advanced Technologies, Shahrekord University of Medical Sciences, Shahrekord, Iran
| | - Mehdi Hosseinzadeh
- Health Management and Economics Research Center, Iran University of Medical Sciences, Tehran, Iran
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12
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Manicka S, Levin M. Modeling somatic computation with non-neural bioelectric networks. Sci Rep 2019; 9:18612. [PMID: 31819119 PMCID: PMC6901451 DOI: 10.1038/s41598-019-54859-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 11/13/2019] [Indexed: 02/08/2023] Open
Abstract
The field of basal cognition seeks to understand how adaptive, context-specific behavior occurs in non-neural biological systems. Embryogenesis and regeneration require plasticity in many tissue types to achieve structural and functional goals in diverse circumstances. Thus, advances in both evolutionary cell biology and regenerative medicine require an understanding of how non-neural tissues could process information. Neurons evolved from ancient cell types that used bioelectric signaling to perform computation. However, it has not been shown whether or how non-neural bioelectric cell networks can support computation. We generalize connectionist methods to non-neural tissue architectures, showing that a minimal non-neural Bio-Electric Network (BEN) model that utilizes the general principles of bioelectricity (electrodiffusion and gating) can compute. We characterize BEN behaviors ranging from elementary logic gates to pattern detectors, using both fixed and transient inputs to recapitulate various biological scenarios. We characterize the mechanisms of such networks using dynamical-systems and information-theory tools, demonstrating that logic can manifest in bidirectional, continuous, and relatively slow bioelectrical systems, complementing conventional neural-centric architectures. Our results reveal a variety of non-neural decision-making processes as manifestations of general cellular biophysical mechanisms and suggest novel bioengineering approaches to construct functional tissues for regenerative medicine and synthetic biology as well as new machine learning architectures.
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Affiliation(s)
- Santosh Manicka
- Allen Discovery Center, 200 College Ave., Tufts University, Medford, MA, 02155, USA
| | - Michael Levin
- Allen Discovery Center, 200 College Ave., Tufts University, Medford, MA, 02155, USA.
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13
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Abstract
Synthetic biology uses living cells as the substrate for performing human-defined computations. Many current implementations of cellular computing are based on the “genetic circuit” metaphor, an approximation of the operation of silicon-based computers. Although this conceptual mapping has been relatively successful, we argue that it fundamentally limits the types of computation that may be engineered inside the cell, and fails to exploit the rich and diverse functionality available in natural living systems. We propose the notion of “cellular supremacy” to focus attention on domains in which biocomputing might offer superior performance over traditional computers. We consider potential pathways toward cellular supremacy, and suggest application areas in which it may be found. Synthetic biology uses cells as its computing substrate, often based on the genetic circuit concept. In this Perspective, the authors argue that existing synthetic biology approaches based on classical models of computation limit the potential of biocomputing, and propose that living organisms have under-exploited capabilities.
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14
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Stoof R, Wood A, Goñi-Moreno Á. A Model for the Spatiotemporal Design of Gene Regulatory Circuits †. ACS Synth Biol 2019; 8:2007-2016. [PMID: 31429541 DOI: 10.1021/acssynbio.9b00022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Mathematical modeling assists the design of synthetic regulatory networks by providing a detailed mechanistic understanding of biological systems. Models that can predict the performance of a design are fundamental for synthetic biology since they minimize iterations along the design-build-test lifecycle. Such predictability depends crucially on what assumptions (i.e., biological simplifications) the model considers. Here, we challenge a common assumption when it comes to the modeling of bacterial-based gene regulation: considering negligible the effects of intracellular physical space. It is commonly assumed that molecules, such as transcription factors (TF), are homogeneously distributed inside a cell, so there is no need to model their diffusion. We describe a mathematical model that accounts for molecular diffusion and show how simulations of network performance are decisively affected by the distance between its components. Specifically, the model focuses on the search by a TF for its target promoter. The combination of local searches, via one-dimensional sliding along the chromosome, and global searches, via three-dimensional diffusion through the cytoplasm, determine TF-promoter interplay. Previous experimental results with engineered bacteria in which the distance between TF source and target was minimized or enlarged were successfully reproduced by the spatially resolved model we introduce here. This suggests that the spatial specification of the circuit alone can be exploited as a design parameter in synthetic biology to select programmable output levels.
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Affiliation(s)
- Ruud Stoof
- School of Computing, Newcastle University, Newcastle upon Tyne NE4 5TG, U.K
| | - Alexander Wood
- School of Computing, Newcastle University, Newcastle upon Tyne NE4 5TG, U.K
| | - Ángel Goñi-Moreno
- School of Computing, Newcastle University, Newcastle upon Tyne NE4 5TG, U.K
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15
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Hallinan JS, Wipat A, Kitney R, Woods S, Taylor K, Goñi‐Moreno A. Future‐proofing synthetic biology: educating the next generation. ENGINEERING BIOLOGY 2019. [DOI: 10.1049/enb.2019.0001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
| | - Anil Wipat
- School of ComputingNewcastle UniversityNewcastle upon TyneUK
| | - Richard Kitney
- Department of BioengineeringImperial College LondonLondonUK
| | - Simon Woods
- Policy, Ethics and Life Sciences (PEALS) Research CentreNewcastle UniversityNewcastle upon TyneUK
| | - Ken Taylor
- Policy, Ethics and Life Sciences (PEALS) Research CentreNewcastle UniversityNewcastle upon TyneUK
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16
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Goñi-Moreno A, de la Cruz F, Rodríguez-Patón A, Amos M. Dynamical Task Switching in Cellular Computers. Life (Basel) 2019; 9:E14. [PMID: 30691149 PMCID: PMC6463194 DOI: 10.3390/life9010014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 12/23/2018] [Accepted: 01/23/2019] [Indexed: 01/24/2023] Open
Abstract
We present a scheme for implementing a version of task switching in engineered bacteria, based on the manipulation of plasmid copy numbers. Our method allows for the embedding of multiple computations in a cellular population, whilst minimising resource usage inefficiency. We describe the results of computational simulations of our model, and discuss the potential for future work in this area.
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Affiliation(s)
- Angel Goñi-Moreno
- School of Computing, Newcastle University, Newcastle Upon Tyne NE4 5TG, UK.
| | - Fernando de la Cruz
- Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria, 39011 Santander, Spain.
| | - Alfonso Rodríguez-Patón
- Departamento de Inteligencia Artificial, Universidad Politécnica de Madrid, 28660 Madrid, Spain.
| | - Martyn Amos
- Department of Computer and Information Sciences, Northumbria University, Newcastle upon Tyne NE1 8ST, UK.
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17
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Mahajan T, Rai K. A novel optogenetically tunable frequency modulating oscillator. PLoS One 2018; 13:e0183242. [PMID: 29389936 PMCID: PMC5794059 DOI: 10.1371/journal.pone.0183242] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Accepted: 08/01/2017] [Indexed: 12/22/2022] Open
Abstract
Synthetic biology has enabled the creation of biological reconfigurable circuits, which perform multiple functions monopolizing a single biological machine; Such a system can switch between different behaviours in response to environmental cues. Previous work has demonstrated switchable dynamical behaviour employing reconfigurable logic gate genetic networks. Here we describe a computational framework for reconfigurable circuits in E.coli using combinations of logic gates, and also propose the biological implementation. The proposed system is an oscillator that can exhibit tunability of frequency and amplitude of oscillations. Further, the frequency of operation can be changed optogenetically. Insilico analysis revealed that two-component light systems, in response to light within a frequency range, can be used for modulating the frequency of the oscillator or stopping the oscillations altogether. Computational modelling reveals that mixing two colonies of E.coli oscillating at different frequencies generates spatial beat patterns. Further, we show that these oscillations more robustly respond to input perturbations compared to the base oscillator, to which the proposed oscillator is a modification. Compared to the base oscillator, the proposed system shows faster synchronization in a colony of cells for a larger region of the parameter space. Additionally, the proposed oscillator also exhibits lesser synchronization error in the transient period after input perturbations. This provides a strong basis for the construction of synthetic reconfigurable circuits in bacteria and other organisms, which can be scaled up to perform functions in the field of time dependent drug delivery with tunable dosages, and sets the stage for further development of circuits with synchronized population level behaviour.
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Affiliation(s)
- Tarun Mahajan
- Department of Electrical Engineering, Indian Institute of Technology Delhi, New Delhi, India
- * E-mail:
| | - Kshitij Rai
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, New Delhi, India
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18
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Kobayashi K, Hiraishi K. Design of Probabilistic Boolean Networks Based on Network Structure and Steady-State Probabilities. IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 2017; 28:1966-1971. [PMID: 27295690 DOI: 10.1109/tnnls.2016.2572063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In this brief, we consider the problem of finding a probabilistic Boolean network (PBN) based on a network structure and desired steady-state properties. In systems biology and synthetic biology, such problems are important as an inverse problem. Using a matrix-based representation of PBNs, a solution method for this problem is proposed. The problem of finding a BN has been studied so far. In the problem of finding a PBN, we must calculate not only the Boolean functions, but also the probabilities of selecting a Boolean function and the number of candidates of the Boolean functions. Hence, the problem of finding a PBN is more difficult than that of finding a BN. The effectiveness of the proposed method is presented by numerical examples.
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19
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Goñi-Moreno Á, Benedetti I, Kim J, de Lorenzo V. Deconvolution of Gene Expression Noise into Spatial Dynamics of Transcription Factor-Promoter Interplay. ACS Synth Biol 2017; 6:1359-1369. [PMID: 28355056 DOI: 10.1021/acssynbio.6b00397] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Gene expression noise is not only the mere consequence of stochasticity, but also a signal that reflects the upstream physical dynamics of the cognate molecular machinery. Soil bacteria facing recalcitrant pollutants exploit noise of catabolic promoters to deploy beneficial phenotypes such as metabolic bet-hedging and/or division of biochemical labor. Although the role of upstream promoter-regulator interplay in the origin of this noise is little understood, its specifications are probably ciphered in flow cytometry data patterns. We studied Pm promoter activity of the environmental bacterium Pseudomonas putida and its cognate regulator XylS by following expression of Pm-gfp fusions in single cells. Using mathematical modeling and computational simulations, we determined the kinetic properties of the system and used them as a baseline code to interpret promoter activity in terms of upstream regulator dynamics. Transcriptional noise was predicted to depend on the intracellular physical distance between regulator source (where XylS is produced) and the target promoter. Experiments with engineered bacteria in which this distance is minimized or enlarged confirmed the predicted effects of source/target proximity on noise patterns. This approach allowed deconvolution of cytometry data into mechanistic information on gene expression flow. It also provided a basis for selecting programmable noise levels in synthetic regulatory circuits.
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Affiliation(s)
- Ángel Goñi-Moreno
- Systems Biology Program, Centro Nacional de Biotecnología CSIC, Campus de Cantoblanco, Madrid 28049, Spain
| | - Ilaria Benedetti
- Systems Biology Program, Centro Nacional de Biotecnología CSIC, Campus de Cantoblanco, Madrid 28049, Spain
| | - Juhyun Kim
- Systems Biology Program, Centro Nacional de Biotecnología CSIC, Campus de Cantoblanco, Madrid 28049, Spain
| | - Víctor de Lorenzo
- Systems Biology Program, Centro Nacional de Biotecnología CSIC, Campus de Cantoblanco, Madrid 28049, Spain
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20
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Figueiredo D, Martins MA, Chaves M. Applying differential dynamic logic to reconfigurable biological networks. Math Biosci 2017; 291:10-20. [PMID: 28610888 DOI: 10.1016/j.mbs.2017.05.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/29/2017] [Indexed: 11/25/2022]
Abstract
Qualitative and quantitative modeling frameworks are widely used for analysis of biological regulatory networks, the former giving a preliminary overview of the system's global dynamics and the latter providing more detailed solutions. Another approach is to model biological regulatory networks as hybrid systems, i.e., systems which can display both continuous and discrete dynamic behaviors. Actually, the development of synthetic biology has shown that this is a suitable way to think about biological systems, which can often be constructed as networks with discrete controllers, and present hybrid behaviors. In this paper we discuss this approach as a special case of the reconfigurability paradigm, well studied in Computer Science (CS). In CS there are well developed computational tools to reason about hybrid systems. We argue that it is worth applying such tools in a biological context. One interesting tool is differential dynamic logic (dL), which has recently been developed by Platzer and applied to many case-studies. In this paper we discuss some simple examples of biological regulatory networks to illustrate how dL can be used as an alternative, or also as a complement to methods already used.
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Affiliation(s)
- Daniel Figueiredo
- CIDMA - Center for R&D Mathematics and Applications, Department of Mathematics, University of Aveiro, Portugal
| | - Manuel A Martins
- CIDMA - Center for R&D Mathematics and Applications, Department of Mathematics, University of Aveiro, Portugal.
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21
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Foo M, Sawlekar R, Bates DG. Exploiting the dynamic properties of covalent modification cycle for the design of synthetic analog biomolecular circuitry. J Biol Eng 2016; 10:15. [PMID: 27872658 PMCID: PMC5108087 DOI: 10.1186/s13036-016-0036-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 10/19/2016] [Indexed: 01/22/2023] Open
Abstract
Background Cycles of covalent modification are ubiquitous motifs in cellular signalling. Although such signalling cycles are implemented via a highly concise set of chemical reactions, they have been shown to be capable of producing multiple distinct input-output mapping behaviours – ultrasensitive, hyperbolic, signal-transducing and threshold-hyperbolic. Results In this paper, we show how the set of chemical reactions underlying covalent modification cycles can be exploited for the design of synthetic analog biomolecular circuitry. We show that biomolecular circuits based on the dynamics of covalent modification cycles allow (a) the computation of nonlinear operators using far fewer chemical reactions than purely abstract designs based on chemical reaction network theory, and (b) the design of nonlinear feedback controllers with strong performance and robustness properties. Conclusions Our designs provide a more efficient route for translation of complex circuits and systems from chemical reactions to DNA strand displacement-based chemistry, thus facilitating their experimental implementation in future Synthetic Biology applications.
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Affiliation(s)
- Mathias Foo
- Warwick Integrative Synthetic Biology Centre, School of Engineering, University of Warwick, Coventry, CV4 7AL UK
| | - Rucha Sawlekar
- Warwick Integrative Synthetic Biology Centre, School of Engineering, University of Warwick, Coventry, CV4 7AL UK
| | - Declan G Bates
- Warwick Integrative Synthetic Biology Centre, School of Engineering, University of Warwick, Coventry, CV4 7AL UK
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22
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Van Hove B, Love AM, Ajikumar PK, De Mey M. Programming Biology: Expanding the Toolset for the Engineering of Transcription. Synth Biol (Oxf) 2016. [DOI: 10.1007/978-3-319-22708-5_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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23
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Ball P. Forging patterns and making waves from biology to geology: a commentary on Turing (1952) 'The chemical basis of morphogenesis'. Philos Trans R Soc Lond B Biol Sci 2015; 373:rsta.2014.0218. [PMID: 25750229 DOI: 10.1098/rsta.2014.0218] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/17/2015] [Indexed: 05/21/2023] Open
Abstract
Alan Turing was neither a biologist nor a chemist, and yet the paper he published in 1952, 'The chemical basis of morphogenesis', on the spontaneous formation of patterns in systems undergoing reaction and diffusion of their ingredients has had a substantial impact on both fields, as well as in other areas as disparate as geomorphology and criminology. Motivated by the question of how a spherical embryo becomes a decidedly non-spherical organism such as a human being, Turing devised a mathematical model that explained how random fluctuations can drive the emergence of pattern and structure from initial uniformity. The spontaneous appearance of pattern and form in a system far away from its equilibrium state occurs in many types of natural process, and in some artificial ones too. It is often driven by very general mechanisms, of which Turing's model supplies one of the most versatile. For that reason, these patterns show striking similarities in systems that seem superficially to share nothing in common, such as the stripes of sand ripples and of pigmentation on a zebra skin. New examples of 'Turing patterns' in biology and beyond are still being discovered today. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.
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Affiliation(s)
- Philip Ball
- 18 Hillcourt Road, East Dulwich, London SE22 0PE, UK
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24
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Nguyen LK, Cavadas MAS, Kholodenko BN, Frank TD, Cheong A. Species differential regulation of COX2 can be described by an NFκB-dependent logic AND gate. Cell Mol Life Sci 2015; 72:2431-43. [PMID: 25697863 PMCID: PMC4439527 DOI: 10.1007/s00018-015-1850-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Revised: 01/30/2015] [Accepted: 02/03/2015] [Indexed: 12/25/2022]
Abstract
Cyclooxygenase 2 (COX2), a key regulatory enzyme of the prostaglandin/eicosanoid pathway, is an important target for anti-inflammatory therapy. It is highly induced by pro-inflammatory cytokines in a Nuclear factor kappa B (NFκB)-dependent manner. However, the mechanisms determining the amplitude and dynamics of this important pro-inflammatory event are poorly understood. Furthermore, there is significant difference between human and mouse COX2 expression in response to the inflammatory stimulus tumor necrosis factor alpha (TNFα). Here, we report the presence of a molecular logic AND gate composed of two NFκB response elements (NREs) which controls the expression of human COX2 in a switch-like manner. Combining quantitative kinetic modeling and thermostatistical analysis followed by experimental validation in iterative cycles, we show that the human COX2 expression machinery regulated by NFκB displays features of a logic AND gate. We propose that this provides a digital, noise-filtering mechanism for a tighter control of expression in response to TNFα, such that a threshold level of NFκB activation is required before the promoter becomes active and initiates transcription. This NFκB-regulated AND gate is absent in the mouse COX2 promoter, most likely contributing to its differential graded response in promoter activity and protein expression to TNFα. Our data suggest that the NFκB-regulated AND gate acts as a novel mechanism for controlling the expression of human COX2 to TNFα, and its absence in the mouse COX2 provides the foundation for further studies on understanding species-specific differential gene regulation.
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Affiliation(s)
- Lan K Nguyen
- Systems Biology Ireland, University College Dublin, Dublin 4, Ireland
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25
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DiSCUS: A Simulation Platform for Conjugation Computing. UNCONVENTIONAL COMPUTATION AND NATURAL COMPUTATION 2015. [DOI: 10.1007/978-3-319-21819-9_13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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26
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Kobayashi K, Hiraishi K. ILP/SMT-Based Method for Design of Boolean Networks Based on Singleton Attractors. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2014; 11:1253-1259. [PMID: 26357060 DOI: 10.1109/tcbb.2014.2325011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Attractors in gene regulatory networks represent cell types or states of cells. In system biology and synthetic biology, it is important to generate gene regulatory networks with desired attractors. In this paper, we focus on a singleton attractor, which is also called a fixed point. Using a Boolean network (BN) model, we consider the problem of finding Boolean functions such that the system has desired singleton attractors and has no undesired singleton attractors. To solve this problem, we propose a matrix-based representation of BNs. Using this representation, the problem of finding Boolean functions can be rewritten as an Integer Linear Programming (ILP) problem and a Satisfiability Modulo Theories (SMT) problem. Furthermore, the effectiveness of the proposed method is shown by a numerical example on a WNT5A network, which is related to melanoma. The proposed method provides us a basic method for design of gene regulatory networks.
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27
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Huang H, Densmore D. Integration of microfluidics into the synthetic biology design flow. LAB ON A CHIP 2014; 14:3459-74. [PMID: 25012162 DOI: 10.1039/c4lc00509k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
One goal of synthetic biology is to design and build genetic circuits in living cells for a range of applications. Major challenges in these efforts include increasing the scalability and robustness of engineered biological systems and streamlining and automating the synthetic biology workflow of specification-design-assembly-verification. We present here a summary of the advances in microfluidic technology, particularly microfluidic large scale integration, that can be used to address the challenges facing each step of the synthetic biology workflow. Microfluidic technologies allow precise control over the flow of biological content within microscale devices, and thus may provide more reliable and scalable construction of synthetic biological systems. The integration of microfluidics and synthetic biology has the capability to produce rapid prototyping platforms for characterization of genetic devices, testing of biotherapeutics, and development of biosensors.
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Affiliation(s)
- Haiyao Huang
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA.
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28
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Razavi S, Su S, Inoue T. Cellular signaling circuits interfaced with synthetic, post-translational, negating Boolean logic devices. ACS Synth Biol 2014; 3:676-85. [PMID: 25000210 PMCID: PMC4169742 DOI: 10.1021/sb500222z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Indexed: 12/11/2022]
Abstract
A negating functionality is fundamental to information processing of logic circuits within cells and computers. Aiming to adapt unutilized electronic concepts to the interrogation of signaling circuits in cells, we first took a bottom-up strategy whereby we created protein-based devices that perform negating Boolean logic operations such as NOT, NOR, NAND, and N-IMPLY. These devices function in living cells within a minute by precisely commanding the localization of an activator molecule among three subcellular spaces. We networked these synthetic gates to an endogenous signaling circuit and devised a physiological output. In search of logic functions in signal transduction, we next took a top-down approach and computationally screened 108 signaling pathways to identify commonalities and differences between these biological pathways and electronic circuits. This combination of synthetic and systems approaches will guide us in developing foundations for deconstruction of intricate cell signaling, as well as construction of biomolecular computers.
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Affiliation(s)
- Shiva Razavi
- Department of Biomedical Engineering, Department of Cell Biology, and Center for Cell
Dynamics, Johns Hopkins University School
of Medicine, Baltimore, Maryland 21205, United
States
| | - Steven Su
- Department of Biomedical Engineering, Department of Cell Biology, and Center for Cell
Dynamics, Johns Hopkins University School
of Medicine, Baltimore, Maryland 21205, United
States
| | - Takanari Inoue
- Department of Biomedical Engineering, Department of Cell Biology, and Center for Cell
Dynamics, Johns Hopkins University School
of Medicine, Baltimore, Maryland 21205, United
States
- Japan
Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan
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29
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Singh V. Recent advances and opportunities in synthetic logic gates engineering in living cells. SYSTEMS AND SYNTHETIC BIOLOGY 2014; 8:271-82. [PMID: 26396651 DOI: 10.1007/s11693-014-9154-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2014] [Revised: 08/09/2014] [Accepted: 08/23/2014] [Indexed: 01/03/2023]
Abstract
Recently, a number of synthetic biologic gates including AND, OR, NOR, NOT, XOR and NAND have been engineered and characterized in a wide range of hosts. The hope in the emerging synthetic biology community is to construct an inventory of well-characterized parts and install distinct gene and circuit behaviours that are externally controllable. Though the field is still growing and major successes are yet to emerge, the payoffs are predicted to be significant. In this review, we highlight specific examples of logic gates engineering with applications towards fundamental understanding of network complexity and generating a novel socially useful applications.
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Affiliation(s)
- Vijai Singh
- Department of Biotechnology, Invertis University, Bareilly- Lucknow National Highway-24, Bareilly, 243123 India ; Synthetic Biology Laboratory, School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, Ulju-gun, Ulsan, 689-798 Republic of Korea
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30
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A design principle underlying the paradoxical roles of E3 ubiquitin ligases. Sci Rep 2014; 4:5573. [PMID: 24994517 PMCID: PMC5381699 DOI: 10.1038/srep05573] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Accepted: 06/16/2014] [Indexed: 12/25/2022] Open
Abstract
E3 ubiquitin ligases are important cellular components that determine the specificity of proteolysis in the ubiquitin-proteasome system. However, an increasing number of studies have indicated that E3 ubiquitin ligases also participate in transcription. Intrigued by the apparently paradoxical functions of E3 ubiquitin ligases in both proteolysis and transcriptional activation, we investigated the underlying design principles using mathematical modeling. We found that the antagonistic functions integrated in E3 ubiquitin ligases can prevent any undesirable sustained activation of downstream genes when E3 ubiquitin ligases are destabilized by unexpected perturbations. Interestingly, this design principle of the system is similar to the operational principle of a safety interlock device in engineering systems, which prevents a system from abnormal operation unless stability is guaranteed.
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31
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Bogdał MN, Hat B, Kochańczyk M, Lipniacki T. Levels of pro-apoptotic regulator Bad and anti-apoptotic regulator Bcl-xL determine the type of the apoptotic logic gate. BMC SYSTEMS BIOLOGY 2013; 7:67. [PMID: 23883471 PMCID: PMC3750306 DOI: 10.1186/1752-0509-7-67] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 07/11/2013] [Indexed: 01/25/2023]
Abstract
BACKGROUND Apoptosis is a tightly regulated process: cellular survive-or-die decisions cannot be accidental and must be unambiguous. Since the suicide program may be initiated in response to numerous stress stimuli, signals transmitted through a number of checkpoints have to be eventually integrated. RESULTS In order to analyze possible mechanisms of the integration of multiple pro-apoptotic signals, we constructed a simple model of the Bcl-2 family regulatory module. The module collects upstream signals and processes them into life-or-death decisions by employing interactions between proteins from three subgroups of the Bcl-2 family: pro-apoptotic multidomain effectors, pro-survival multidomain restrainers, and pro-apoptotic single domain BH3-only proteins. Although the model is based on ordinary differential equations (ODEs), it demonstrates that the Bcl-2 family module behaves akin to a Boolean logic gate of the type dependent on levels of BH3-only proteins (represented by Bad) and restrainers (represented by Bcl-xL). A low level of pro-apoptotic Bad or a high level of pro-survival Bcl-xL implies gate AND, which allows for the initiation of apoptosis only when two stress stimuli are simultaneously present: the rise of the p53 killer level and dephosphorylation of kinase Akt. In turn, a high level of Bad or a low level of Bcl-xL implies gate OR, for which any of these stimuli suffices for apoptosis. CONCLUSIONS Our study sheds light on possible signal integration mechanisms in cells, and spans a bridge between modeling approaches based on ODEs and on Boolean logic. In the proposed scheme, logic gates switching results from the change of relative abundances of interacting proteins in response to signals and involves system bistability. Consequently, the regulatory system may process two analogous inputs into a digital survive-or-die decision.
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Affiliation(s)
- Marta N Bogdał
- Institute of Fundamental Technological Research, Polish Academy of Sciences, Warsaw 02-106, Poland
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Moe-Behrens GH. The biological microprocessor, or how to build a computer with biological parts. Comput Struct Biotechnol J 2013; 7:e201304003. [PMID: 24688733 PMCID: PMC3962179 DOI: 10.5936/csbj.201304003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 06/17/2013] [Accepted: 06/20/2013] [Indexed: 01/21/2023] Open
Abstract
Systemics, a revolutionary paradigm shift in scientific thinking, with applications in systems biology, and synthetic biology, have led to the idea of using silicon computers and their engineering principles as a blueprint for the engineering of a similar machine made from biological parts. Here we describe these building blocks and how they can be assembled to a general purpose computer system, a biological microprocessor. Such a system consists of biological parts building an input / output device, an arithmetic logic unit, a control unit, memory, and wires (busses) to interconnect these components. A biocomputer can be used to monitor and control a biological system.
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Goñi-Moreno A, Amos M, de la Cruz F. Multicellular computing using conjugation for wiring. PLoS One 2013; 8:e65986. [PMID: 23840385 PMCID: PMC3688716 DOI: 10.1371/journal.pone.0065986] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 05/01/2013] [Indexed: 12/24/2022] Open
Abstract
Recent efforts in synthetic biology have focussed on the implementation of logical functions within living cells. One aim is to facilitate both internal "re-programming" and external control of cells, with potential applications in a wide range of domains. However, fundamental limitations on the degree to which single cells may be re-engineered have led to a growth of interest in multicellular systems, in which a "computation" is distributed over a number of different cell types, in a manner analogous to modern computer networks. Within this model, individual cell type perform specific sub-tasks, the results of which are then communicated to other cell types for further processing. The manner in which outputs are communicated is therefore of great significance to the overall success of such a scheme. Previous experiments in distributed cellular computation have used global communication schemes, such as quorum sensing (QS), to implement the "wiring" between cell types. While useful, this method lacks specificity, and limits the amount of information that may be transferred at any one time. We propose an alternative scheme, based on specific cell-cell conjugation. This mechanism allows for the direct transfer of genetic information between bacteria, via circular DNA strands known as plasmids. We design a multi-cellular population that is able to compute, in a distributed fashion, a Boolean XOR function. Through this, we describe a general scheme for distributed logic that works by mixing different strains in a single population; this constitutes an important advantage of our novel approach. Importantly, the amount of genetic information exchanged through conjugation is significantly higher than the amount possible through QS-based communication. We provide full computational modelling and simulation results, using deterministic, stochastic and spatially-explicit methods. These simulations explore the behaviour of one possible conjugation-wired cellular computing system under different conditions, and provide baseline information for future laboratory implementations.
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Affiliation(s)
- Angel Goñi-Moreno
- Systems Biology Program, Centro Nacional de Biotecnología CSIC, Cantoblanco-Madrid, Spain.
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