51
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Optogenetic control of the lac operon for bacterial chemical and protein production. Nat Chem Biol 2020; 17:71-79. [PMID: 32895498 DOI: 10.1038/s41589-020-0639-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2019] [Accepted: 07/31/2020] [Indexed: 12/24/2022]
Abstract
Control of the lac operon with isopropyl β-D-1-thiogalactopyranoside (IPTG) has been used to regulate gene expression in Escherichia coli for countless applications, including metabolic engineering and recombinant protein production. However, optogenetics offers unique capabilities, such as easy tunability, reversibility, dynamic induction strength and spatial control, that are difficult to obtain with chemical inducers. We have developed a series of circuits for optogenetic regulation of the lac operon, which we call OptoLAC, to control gene expression from various IPTG-inducible promoters using only blue light. Applying them to metabolic engineering improves mevalonate and isobutanol production by 24% and 27% respectively, compared to IPTG induction, in light-controlled fermentations scalable to at least two-litre bioreactors. Furthermore, OptoLAC circuits enable control of recombinant protein production, reaching yields comparable to IPTG induction but with easier tunability of expression. OptoLAC circuits are potentially useful to confer light control over other cell functions originally designed to be IPTG-inducible.
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52
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Hartmann D, Smith JM, Mazzotti G, Chowdhry R, Booth MJ. Controlling gene expression with light: a multidisciplinary endeavour. Biochem Soc Trans 2020; 48:1645-1659. [PMID: 32657338 PMCID: PMC7458398 DOI: 10.1042/bst20200014] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/21/2022]
Abstract
The expression of a gene to a protein is one of the most vital biological processes. The use of light to control biology offers unparalleled spatiotemporal resolution from an external, orthogonal signal. A variety of methods have been developed that use light to control the steps of transcription and translation of specific genes into proteins, for cell-free to in vivo biotechnology applications. These methods employ techniques ranging from the modification of small molecules, nucleic acids and proteins with photocages, to the engineering of proteins involved in gene expression using naturally light-sensitive proteins. Although the majority of currently available technologies employ ultraviolet light, there has been a recent increase in the use of functionalities that work at longer wavelengths of light, to minimise cellular damage and increase tissue penetration. Here, we discuss the different chemical and biological methods employed to control gene expression, while also highlighting the central themes and the most exciting applications within this diverse field.
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Affiliation(s)
- Denis Hartmann
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Jefferson M. Smith
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Giacomo Mazzotti
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Razia Chowdhry
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
| | - Michael J. Booth
- Chemistry Research Laboratory, University of Oxford, Oxford OX1 3TA, U.K
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53
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Baumschlager A, Rullan M, Khammash M. Exploiting natural chemical photosensitivity of anhydrotetracycline and tetracycline for dynamic and setpoint chemo-optogenetic control. Nat Commun 2020; 11:3834. [PMID: 32737309 PMCID: PMC7395757 DOI: 10.1038/s41467-020-17677-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/02/2020] [Indexed: 01/02/2023] Open
Abstract
The transcriptional inducer anhydrotetracycline (aTc) and the bacteriostatic antibiotic tetracycline (Tc) are commonly used in all fields of biology for control of transcription or translation. A drawback of these and other small molecule inducers is the difficulty of their removal from cell cultures, limiting their application for dynamic control. Here, we describe a simple method to overcome this limitation, and show that the natural photosensitivity of aTc/Tc can be exploited to turn them into highly predictable optogenetic transcriptional- and growth-regulators. This new optogenetic class uniquely features both dynamic and setpoint control which act via population-memory adjustable through opto-chemical modulation. We demonstrate this method by applying it for dynamic gene expression control and for enhancing the performance of an existing optogenetic system. We then expand the utility of the aTc system by constructing a new chemical bandpass filter that increases its aTc response range. The simplicity of our method enables scientists and biotechnologists to use their existing systems employing aTc/Tc for dynamic optogenetic experiments without genetic modification.
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Affiliation(s)
- Armin Baumschlager
- Department of Biosystems Science and Engineering (D-BSSE), ETH-Zürich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Marc Rullan
- Department of Biosystems Science and Engineering (D-BSSE), ETH-Zürich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Mustafa Khammash
- Department of Biosystems Science and Engineering (D-BSSE), ETH-Zürich, Mattenstrasse 26, 4058, Basel, Switzerland.
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54
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Li G, Wang F, Yang W, Wang W, Li G, Wang Y, Liu L. Imaging with Optogenetically Engineered Living Cells as a Photodetector. ACTA ACUST UNITED AC 2020; 3:e1800319. [PMID: 32648700 DOI: 10.1002/adbi.201800319] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 06/03/2019] [Indexed: 11/05/2022]
Abstract
Biosyncretic systems integrating biological components with electromechanical devices have recently become a promising technology, in which biological components are used as actuators or sensing elements with higher-level performance than artificial systems. Here, a biosyncretic imaging system using an optogenetically engineered living cell as a photodetector is shown. The photoresponsive properties of the cell, such as spectrum and response range, dynamic characteristics, are measured and indicate that the cell functions as an excellent photodetector. In the system, the cell is directly utilized to generate light-triggered ionic currents, which encode the spatial image information and therefore are used to reconstruct the scenes under the view based on compressive sensing. Imaging with the cell-based photodetector is successfully performed by acquiring high-definition images using the system. The system also displays function superiority to a commercial photodiode, such as wider dynamic responsivity range. This work represents a step toward directly imaging with living materials and paves a new road for the development of future on-body bionic devices.
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Affiliation(s)
- Gongxin Li
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.,Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, 110016, China.,University of the Chinese Academy of Sciences, Beijing, 100049, China.,Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education), Institute of Automation, Jiangnan University, Wuxi, 214122, China
| | - Feifei Wang
- Department of Chemistry, Stanford University, Stanford, CA, 94305, USA
| | - Wenguang Yang
- School of Electromechanical and Automotive Engineering, Yantai University, Yantai, 264005, China
| | - Wenxue Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.,Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, 110016, China.,University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Guangyong Li
- Department of Electrical and Computer Engineering, University of Pittsburgh, PA, 15213, USA
| | - Yuechao Wang
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.,Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, 110016, China.,University of the Chinese Academy of Sciences, Beijing, 100049, China
| | - Lianqing Liu
- State Key Laboratory of Robotics, Shenyang Institute of Automation, Chinese Academy of Sciences, Shenyang, 110016, China.,Institutes for Robotics and Intelligent Manufacturing, Chinese Academy of Sciences, Shenyang, 110016, China.,University of the Chinese Academy of Sciences, Beijing, 100049, China
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55
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Evolution-inspired design of multicolored photoswitches from a single cyanobacteriochrome scaffold. Proc Natl Acad Sci U S A 2020; 117:15573-15580. [PMID: 32571944 DOI: 10.1073/pnas.2004273117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Cyanobacteriochromes (CBCRs) are small, bistable linear tetrapyrrole (bilin)-binding light sensors which are typically found as modular components in multidomain cyanobacterial signaling proteins. The CBCR family has been categorized into many lineages that roughly correlate with their spectral diversity, but CBCRs possessing a conserved DXCF motif are found in multiple lineages. DXCF CBCRs typically possess two conserved Cys residues: a first Cys that remains ligated to the bilin chromophore and a second Cys found in the DXCF motif. The second Cys often forms a second thioether linkage, providing a mechanism to sense blue and violet light. DXCF CBCRs have been described with blue/green, blue/orange, blue/teal, and green/teal photocycles, and the molecular basis for some of this spectral diversity has been well established. We here characterize AM1_1499g1, an atypical DXCF CBCR that lacks the second cysteine residue and exhibits an orange/green photocycle. Based on prior studies of CBCR spectral tuning, we have successfully engineered seven AM1_1499g1 variants that exhibit robust yellow/teal, green/teal, blue/teal, orange/yellow, yellow/green, green/green, and blue/green photocycles. The remarkable spectral diversity generated by modification of a single CBCR provides a good template for multiplexing synthetic photobiology systems within the same cellular context, thereby bypassing the time-consuming empirical optimization process needed for multiple probes with different protein scaffolds.
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56
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Li X, Zhang C, Xu X, Miao J, Yao J, Liu R, Zhao Y, Chen X, Yang Y. A single-component light sensor system allows highly tunable and direct activation of gene expression in bacterial cells. Nucleic Acids Res 2020; 48:e33. [PMID: 31989175 PMCID: PMC7102963 DOI: 10.1093/nar/gkaa044] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 01/11/2020] [Accepted: 01/16/2020] [Indexed: 11/23/2022] Open
Abstract
Light-regulated modules offer unprecedented new ways to control cellular behaviour with precise spatial and temporal resolution. Among a variety of bacterial light-switchable gene expression systems, single-component systems consisting of single transcription factors would be more useful due to the advantages of speed, simplicity, and versatility. In the present study, we developed a single-component light-activated bacterial gene expression system (eLightOn) based on a novel LOV domain from Rhodobacter sphaeroides (RsLOV). The eLightOn system showed significant improvements over the existing single-component bacterial light-activated expression systems, with benefits including a high ON/OFF ratio of >500-fold, a high activation level, fast activation kinetics, and/or good adaptability. Additionally, the induction characteristics, including regulatory windows, activation kinetics and light sensitivities, were highly tunable by altering the expression level of LexRO. We demonstrated the usefulness of the eLightOn system in regulating cell division and swimming by controlling the expression of the FtsZ and CheZ genes, respectively, as well as constructing synthetic Boolean logic gates using light and arabinose as the two inputs. Taken together, our data indicate that the eLightOn system is a robust and highly tunable tool for quantitative and spatiotemporal control of bacterial gene expression.
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Affiliation(s)
- Xie Li
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Changcheng Zhang
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Xiaopei Xu
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Jun Miao
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Jing Yao
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Renmei Liu
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Yuzheng Zhao
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China
| | - Xianjun Chen
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yi Yang
- Optogenetics & Synthetic Biology Interdisciplinary Research Center, State Key Laboratory of Bioreactor Engineering, Shanghai Collaborative Innovation Center for Biomanufacturing Technology, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,Shanghai Key Laboratory of New Drug Design, School of Pharmacy, East China University of Science and Technology, 130 Mei Long Road, Shanghai 200237, China.,CAS Center for Excellence in Brain Science, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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57
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Huang P, Liu A, Song Y, Hope JM, Cui B, Duan L. Optical Activation of TrkB Signaling. J Mol Biol 2020; 432:3761-3770. [PMID: 32422149 DOI: 10.1016/j.jmb.2020.05.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Revised: 04/30/2020] [Accepted: 05/06/2020] [Indexed: 01/04/2023]
Abstract
Brain-derived neurotrophic factor, via activation of tropomyosin receptor kinase B (TrkB), plays a critical role in neuronal proliferation, differentiation, survival, and death. Dysregulation of TrkB signaling is implicated in neurodegenerative disorders and cancers. Precise activation of TrkB signaling with spatial and temporal resolution is greatly desired to study the dynamic nature of TrkB signaling and its role in related diseases. Here we develop different optogenetic approaches that use light to activate TrkB signaling. Utilizing the photosensitive protein Arabidopsis thaliana cryptochrome 2, the light-inducible homo-interaction of the intracellular domain of TrkB in the cytosol or on the plasma membrane is able to induce the activation of downstream MAPK/ERK and PI3K/Akt signaling as well as the neurite outgrowth of PC12 cells. Moreover, we prove that such strategies are generalizable to other optical homo-dimerizers by demonstrating the optical TrkB activation based on the light-oxygen-voltage domain of aureochrome 1 from Vaucheria frigida. The results open up new possibilities of many other optical platforms to activate TrkB signaling to fulfill customized needs. By comparing all the different strategies, we find that the cryptochrome 2-integrated approach to achieve light-induced cell membrane recruitment and homo-interaction of intracellular domain of TrkB is most efficient in activating TrkB signaling. The optogenetic strategies presented are promising tools to investigate brain-derived neurotrophic factor/TrkB signaling with tight spatial and temporal control.
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Affiliation(s)
- Peiyuan Huang
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Sha Tin, Hong Kong, SAR, China
| | - Aofei Liu
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Yutong Song
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Sha Tin, Hong Kong, SAR, China
| | - Jen M Hope
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Bianxiao Cui
- Department of Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Liting Duan
- Department of Biomedical Engineering, The Chinese University of Hong Kong, Sha Tin, Hong Kong, SAR, China.
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58
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Abstract
Optogenetic tools can provide direct and programmable control of gene expression. Light-inducible recombinases, in particular, offer a powerful method for achieving precise spatiotemporal control of DNA modification. However, to-date this technology has been largely limited to eukaryotic systems. Here, we develop optogenetic recombinases for Escherichia coli that activate in response to blue light. Our approach uses a split recombinase coupled with photodimers, where blue light brings the split protein together to form a functional recombinase. We tested both Cre and Flp recombinases, Vivid and Magnet photodimers, and alternative protein split sites in our analysis. The optimal configuration, Opto-Cre-Vvd, exhibits strong blue light-responsive excision and low ambient light sensitivity. For this system we characterize the effect of light intensity and the temporal dynamics of light-induced recombination. These tools expand the microbial optogenetic toolbox, offering the potential for precise control of DNA excision with light-inducible recombinases in bacteria.
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Affiliation(s)
- Michael B Sheets
- Department of Biomedical Engineering , Boston University , Boston , Massachusetts 02215 , United States
- Biological Design Center , Boston University , Boston , Massachusetts 02215 , United States
| | - Wilson W Wong
- Department of Biomedical Engineering , Boston University , Boston , Massachusetts 02215 , United States
- Biological Design Center , Boston University , Boston , Massachusetts 02215 , United States
| | - Mary J Dunlop
- Department of Biomedical Engineering , Boston University , Boston , Massachusetts 02215 , United States
- Biological Design Center , Boston University , Boston , Massachusetts 02215 , United States
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59
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Hueso-Gil A, Nyerges Á, Pál C, Calles B, de Lorenzo V. Multiple-Site Diversification of Regulatory Sequences Enables Interspecies Operability of Genetic Devices. ACS Synth Biol 2020; 9:104-114. [PMID: 31794196 DOI: 10.1021/acssynbio.9b00375] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The features of the light-responsive cyanobacterial CcaSR regulatory module that determine interoperability of this optogenetic device between Escherichia coli and Pseudomonas putida have been examined. For this, all structural parts (i.e., ho1 and pcyA genes for synthesis of phycocyanobilin, the ccaS/ccaR system from Synechocystis, and its cognate downstream promoter) were maintained but their expression levels and stoichiometry diversified by (i) reassembling them together in a single broad host range, standardized vector and (ii) subjecting the noncoding regulatory sequences to multiple cycles of directed evolution with random genomic mutations (DIvERGE), a recombineering method that intensifies mutation rates within discrete DNA segments. Once passed to P. putida, various clones displayed a wide dynamic range, insignificant leakiness, and excellent capacity in response to green light. Inspection of the evolutionary intermediates pinpointed translational control as the main bottleneck for interoperability and suggested a general approach for easing the exchange of genetic cargoes between different species, i.e., optimization of relative expression levels and upturning of subcomplex stoichiometry.
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Affiliation(s)
- Angeles Hueso-Gil
- Systems Biology Program, Centro Nacional de Biotecnología, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Ákos Nyerges
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged H-6726, Hungary
| | - Csaba Pál
- Synthetic and Systems Biology Unit, Institute of Biochemistry, Biological Research Centre, Szeged H-6726, Hungary
| | - Belén Calles
- Systems Biology Program, Centro Nacional de Biotecnología, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Víctor de Lorenzo
- Systems Biology Program, Centro Nacional de Biotecnología, Campus de Cantoblanco, 28049 Madrid, Spain
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60
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Wiltbank LB, Kehoe DM. Diverse light responses of cyanobacteria mediated by phytochrome superfamily photoreceptors. Nat Rev Microbiol 2020; 17:37-50. [PMID: 30410070 DOI: 10.1038/s41579-018-0110-4] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Cyanobacteria are an evolutionarily and ecologically important group of prokaryotes. They exist in diverse habitats, ranging from hot springs and deserts to glaciers and the open ocean. The range of environments that they inhabit can be attributed in part to their ability to sense and respond to changing environmental conditions. As photosynthetic organisms, one of the most crucial parameters for cyanobacteria to monitor is light. Cyanobacteria can sense various wavelengths of light and many possess a range of bilin-binding photoreceptors belonging to the phytochrome superfamily. Vital cellular processes including growth, phototaxis, cell aggregation and photosynthesis are tuned to environmental light conditions by these photoreceptors. In this Review, we examine the physiological responses that are controlled by members of this diverse family of photoreceptors and discuss the signal transduction pathways through which these photoreceptors operate. We highlight specific examples where the activities of multiple photoreceptors function together to fine-tune light responses. We also discuss the potential application of these photosensing systems in optogenetics and synthetic biology.
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Affiliation(s)
- Lisa B Wiltbank
- Department of Biology, Indiana University, Bloomington, IN, USA
| | - David M Kehoe
- Department of Biology, Indiana University, Bloomington, IN, USA.
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61
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Kowallis KA, Duvall SW, Zhao W, Childers WS. Manipulation of Bacterial Signaling Using Engineered Histidine Kinases. Methods Mol Biol 2020; 2077:141-163. [PMID: 31707657 DOI: 10.1007/978-1-4939-9884-5_10] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Two-component systems allow bacteria to respond to changes in environmental or cytosolic conditions through autophosphorylation of a histidine kinase (HK) and subsequent transfer of the phosphate group to its downstream cognate response regulator (RR). The RR then elicits a cellular response, commonly through regulation of transcription. Engineering two-component system signaling networks provides a strategy to study bacterial signaling mechanisms related to bacterial cell survival, symbiosis, and virulence, and to develop sensory devices in synthetic biology. Here we focus on the principles for engineering the HK to identify unknown signal inputs, test signal transmission mechanisms, design small molecule sensors, and rewire two-component signaling networks.
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Affiliation(s)
| | - Samuel W Duvall
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - Wei Zhao
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA
| | - W Seth Childers
- Department of Chemistry, University of Pittsburgh, Pittsburgh, PA, USA. .,Chevron Science Center, University of Pittsburgh, Pittsburgh, PA, USA.
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62
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Möglich A. Signal transduction in photoreceptor histidine kinases. Protein Sci 2019; 28:1923-1946. [PMID: 31397927 PMCID: PMC6798134 DOI: 10.1002/pro.3705] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 08/06/2019] [Accepted: 08/06/2019] [Indexed: 12/14/2022]
Abstract
Two-component systems (TCS) constitute the predominant means by which prokaryotes read out and adapt to their environment. Canonical TCSs comprise a sensor histidine kinase (SHK), usually a transmembrane receptor, and a response regulator (RR). In signal-dependent manner, the SHK autophosphorylates and in turn transfers the phosphoryl group to the RR which then elicits downstream responses, often in form of altered gene expression. SHKs also catalyze the hydrolysis of the phospho-RR, hence, tightly adjusting the overall degree of RR phosphorylation. Photoreceptor histidine kinases are a subset of mostly soluble, cytosolic SHKs that sense light in the near-ultraviolet to near-infrared spectral range. Owing to their experimental tractability, photoreceptor histidine kinases serve as paradigms and provide unusually detailed molecular insight into signal detection, decoding, and regulation of SHK activity. The synthesis of recent results on receptors with light-oxygen-voltage, bacteriophytochrome and microbial rhodopsin sensor units identifies recurring, joint signaling strategies. Light signals are initially absorbed by the sensor module and converted into subtle rearrangements of α helices, mostly through pivoting and rotation. These conformational transitions propagate through parallel coiled-coil linkers to the effector unit as changes in left-handed superhelical winding. Within the effector, subtle conformations are triggered that modulate the solvent accessibility of residues engaged in the kinase and phosphatase activities. Taken together, a consistent view of the entire trajectory from signal detection to regulation of output emerges. The underlying allosteric mechanisms could widely apply to TCS signaling in general.
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Affiliation(s)
- Andreas Möglich
- Department of BiochemistryUniversität BayreuthBayreuthGermany
- Bayreuth Center for Biochemistry & Molecular BiologyUniversität BayreuthBayreuthGermany
- North‐Bavarian NMR CenterUniversität BayreuthBayreuthGermany
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63
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Hu W, Li Q, Li B, Ma K, Zhang C, Fu X. Optogenetics sheds new light on tissue engineering and regenerative medicine. Biomaterials 2019; 227:119546. [PMID: 31655444 DOI: 10.1016/j.biomaterials.2019.119546] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 10/09/2019] [Accepted: 10/14/2019] [Indexed: 01/23/2023]
Abstract
Optogenetics has demonstrated great potential in the fields of tissue engineering and regenerative medicine, from basic research to clinical applications. Spatiotemporal encoding during individual development has been widely identified and is considered a novel strategy for regeneration. A as a noninvasive method with high spatiotemporal resolution, optogenetics are suitable for this strategy. In this review, we discuss roles of dynamic signal coding in cell physiology and embryonic development. Several optogenetic systems are introduced as ideal optogenetic tools, and their features are compared. In addition, potential applications of optogenetics for tissue engineering are discussed, including light-controlled genetic engineering and regulation of signaling pathways. Furthermore, we present how emerging biomaterials and photoelectric technologies have greatly promoted the clinical application of optogenetics and inspired new concepts for optically controlled therapies. Our summation of currently available data conclusively demonstrates that optogenetic tools are a promising method for elucidating and simulating developmental processes, thus providing vast prospects for tissue engineering and regenerative medicine applications.
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Affiliation(s)
- Wenzhi Hu
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Qiankun Li
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Bingmin Li
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Kui Ma
- Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China
| | - Cuiping Zhang
- Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China.
| | - Xiaobing Fu
- Wound Healing and Cell Biology Laboratory, Institute of Basic Medicine Science, College of Life Science, Chinese PLA General Hospital, 28 Fuxing Road, Beijing, 100853, PR China; Key Laboratory of Tissue Repair and Regeneration of PLA and Beijing Key Research Laboratory of Skin Injury, Repair and Regeneration, Fourth Medical Center, Chinese PLA General Hospital, 100048, Beijing, PR China.
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64
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Gale GAR, Schiavon Osorio AA, Mills LA, Wang B, Lea-Smith DJ, McCormick AJ. Emerging Species and Genome Editing Tools: Future Prospects in Cyanobacterial Synthetic Biology. Microorganisms 2019; 7:E409. [PMID: 31569579 PMCID: PMC6843473 DOI: 10.3390/microorganisms7100409] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 09/22/2019] [Accepted: 09/24/2019] [Indexed: 12/19/2022] Open
Abstract
Recent advances in synthetic biology and an emerging algal biotechnology market have spurred a prolific increase in the availability of molecular tools for cyanobacterial research. Nevertheless, work to date has focused primarily on only a small subset of model species, which arguably limits fundamental discovery and applied research towards wider commercialisation. Here, we review the requirements for uptake of new strains, including several recently characterised fast-growing species and promising non-model species. Furthermore, we discuss the potential applications of new techniques available for transformation, genetic engineering and regulation, including an up-to-date appraisal of current Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein (CRISPR/Cas) and CRISPR interference (CRISPRi) research in cyanobacteria. We also provide an overview of several exciting molecular tools that could be ported to cyanobacteria for more advanced metabolic engineering approaches (e.g., genetic circuit design). Lastly, we introduce a forthcoming mutant library for the model species Synechocystis sp. PCC 6803 that promises to provide a further powerful resource for the cyanobacterial research community.
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Affiliation(s)
- Grant A R Gale
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, UK.
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK.
| | - Alejandra A Schiavon Osorio
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, UK.
| | - Lauren A Mills
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Baojun Wang
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, UK.
- Institute of Quantitative Biology, Biochemistry and Biotechnology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FF, UK.
| | - David J Lea-Smith
- School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, UK.
| | - Alistair J McCormick
- Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK.
- Centre for Synthetic and Systems Biology, University of Edinburgh, Edinburgh EH9 3BF, UK.
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65
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Senoo S, Tandar ST, Kitamura S, Toya Y, Shimizu H. Light‐inducible flux control of triosephosphate isomerase on glycolysis in
Escherichia coli. Biotechnol Bioeng 2019; 116:3292-3300. [DOI: 10.1002/bit.27148] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 07/24/2019] [Accepted: 08/15/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Sachie Senoo
- Department of Bioinformatic Engineering, Graduate School of Information Science and TechnologyOsaka University Osaka Japan
| | - Sebastian Tommi Tandar
- Department of Bioinformatic Engineering, Graduate School of Information Science and TechnologyOsaka University Osaka Japan
| | - Sayaka Kitamura
- Department of Bioinformatic Engineering, Graduate School of Information Science and TechnologyOsaka University Osaka Japan
| | - Yoshihiro Toya
- Department of Bioinformatic Engineering, Graduate School of Information Science and TechnologyOsaka University Osaka Japan
| | - Hiroshi Shimizu
- Department of Bioinformatic Engineering, Graduate School of Information Science and TechnologyOsaka University Osaka Japan
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66
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Mushnikov NV, Fomicheva A, Gomelsky M, Bowman GR. Inducible asymmetric cell division and cell differentiation in a bacterium. Nat Chem Biol 2019; 15:925-931. [PMID: 31406376 PMCID: PMC7439754 DOI: 10.1038/s41589-019-0340-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 07/08/2019] [Indexed: 12/14/2022]
Abstract
Multicellular organisms achieve greater complexity through cell divisions that generate different cell types. We engineered a simple genetic circuit that induces asymmetric cell division and subsequent cell differentiation in Escherichia coli. The circuit involves a scaffolding protein, PopZ, that is stably maintained at a single cell pole over multiple asymmetric cell divisions. PopZ was functionalized to degrade the signaling molecule, c-di-GMP. By regulating synthesis of functionalized PopZ via small molecules or light, we can chemically or optogenetically control the relative abundance of two distinct cell types, characterized by either low or high c-di-GMP levels. Differences in c-di-GMP levels can be transformed into genetically programmable differences in protein complex assembly or gene expression, which in turn produce differential behavior or biosynthetic activities. This study shows emergence of complex biological phenomena from a simple genetic circuit and adds programmable bacterial cell differentiation to the genetic toolbox of synthetic biology and biotechnology.
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Affiliation(s)
| | | | - Mark Gomelsky
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA
| | - Grant R Bowman
- Department of Molecular Biology, University of Wyoming, Laramie, WY, USA.
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67
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Castillo-Hair SM, Baerman EA, Fujita M, Igoshin OA, Tabor JJ. Optogenetic control of Bacillus subtilis gene expression. Nat Commun 2019; 10:3099. [PMID: 31308373 PMCID: PMC6629627 DOI: 10.1038/s41467-019-10906-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 06/07/2019] [Indexed: 01/27/2023] Open
Abstract
The Gram-positive bacterium Bacillus subtilis exhibits complex spatial and temporal gene expression signals. Although optogenetic tools are ideal for studying such processes, none has been engineered for this organism. Here, we port a cyanobacterial light sensor pathway comprising the green/red photoreversible two-component system CcaSR, two metabolic enzymes for production of the chromophore phycocyanobilin (PCB), and an output promoter to control transcription of a gene of interest into B. subtilis. Following an initial non-functional design, we optimize expression of pathway genes, enhance PCB production via a translational fusion of the biosynthetic enzymes, engineer a strong chimeric output promoter, and increase dynamic range with a miniaturized photosensor kinase. Our final design exhibits over 70-fold activation and rapid response dynamics, making it well-suited to studying a wide range of gene regulatory processes. In addition, the synthetic biology methods we develop to port this pathway should make B. subtilis easier to engineer in the future.
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Affiliation(s)
| | - Elliot A Baerman
- Department of Biosciences, Rice University, 6100 Main St., Houston, TX, 77005, USA
| | - Masaya Fujita
- Department of Biology and Biochemistry, University of Houston, 4800 Calhoun Rd., Houston, TX, 77004, USA
| | - Oleg A Igoshin
- Department of Bioengineering, Rice University, 6100 Main St., Houston, TX, 77005, USA
- Department of Biosciences, Rice University, 6100 Main St., Houston, TX, 77005, USA
- Center for Theoretical Biophysics, Rice University, 6100 Main St., Houston, TX, 77005, USA
| | - Jeffrey J Tabor
- Department of Bioengineering, Rice University, 6100 Main St., Houston, TX, 77005, USA.
- Department of Biosciences, Rice University, 6100 Main St., Houston, TX, 77005, USA.
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68
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Majerle A, Schmieden DT, Jerala R, Meyer AS. Synthetic Biology for Multiscale Designed Biomimetic Assemblies: From Designed Self-Assembling Biopolymers to Bacterial Bioprinting. Biochemistry 2019; 58:2095-2104. [PMID: 30957491 DOI: 10.1021/acs.biochem.8b00922] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Nature is based on complex self-assembling systems that span from the nanoscale to the macroscale. We have already begun to design biomimetic systems with properties that have not evolved in nature, based on designed molecular interactions and regulation of biological systems. Synthetic biology is based on the principle of modularity, repurposing diverse building modules to design new types of molecular and cellular assemblies. While we are currently able to use techniques from synthetic biology to design self-assembling molecules and re-engineer functional cells, we still need to use guided assembly to construct biological assemblies at the macroscale. We review the recent strategies for designing biological systems ranging from molecular assemblies based on self-assembly of (poly)peptides to the guided assembly of patterned bacteria, spanning 7 orders of magnitude.
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Affiliation(s)
- Andreja Majerle
- Department of Synthetic Biology and Immunology , National Institute of Chemistry , Hajdrihova 19 , 1000 Ljubljana , Slovenia
| | - Dominik T Schmieden
- Department of Bionanoscience, Kavli Institute of Nanoscience , Delft University of Technology , 2629 HZ Delft , The Netherlands
| | - Roman Jerala
- Department of Synthetic Biology and Immunology , National Institute of Chemistry , Hajdrihova 19 , 1000 Ljubljana , Slovenia
| | - Anne S Meyer
- Department of Biology , University of Rochester , Rochester , New York 14627 , United States
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69
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Lugagne JB, Dunlop MJ. Cell-machine interfaces for characterizing gene regulatory network dynamics. ACTA ACUST UNITED AC 2019; 14:1-8. [PMID: 31579842 DOI: 10.1016/j.coisb.2019.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Gene regulatory networks and the dynamic responses they produce offer a wealth of information about how biological systems process information about their environment. Recently, researchers interested in dissecting these networks have been outsourcing various parts of their experimental workflow to computers. Here we review how, using microfluidic or optogenetic tools coupled with fluorescence imaging, it is now possible to interface cells and computers. These platforms enable scientists to perform informative dynamic stimulations of genetic pathways and monitor their reaction. It is also possible to close the loop and regulate genes in real time, providing an unprecedented view of how signals propagate through the network. Finally, we outline new tools that can be used within the framework of cell-machine interfaces.
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Affiliation(s)
- Jean-Baptiste Lugagne
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Biological Design Center, Boston University, Boston, MA, USA
| | - Mary J Dunlop
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.,Biological Design Center, Boston University, Boston, MA, USA
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70
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DIY optogenetics: Building, programming, and using the Light Plate Apparatus. Methods Enzymol 2019; 624:197-226. [DOI: 10.1016/bs.mie.2019.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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71
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Liu Z, Zhang J, Jin J, Geng Z, Qi Q, Liang Q. Programming Bacteria With Light-Sensors and Applications in Synthetic Biology. Front Microbiol 2018; 9:2692. [PMID: 30467500 PMCID: PMC6236058 DOI: 10.3389/fmicb.2018.02692] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 10/22/2018] [Indexed: 12/11/2022] Open
Abstract
Photo-receptors are widely present in both prokaryotic and eukaryotic cells, which serves as the foundation of tuning cell behaviors with light. While practices in eukaryotic cells have been relatively established, trials in bacterial cells have only been emerging in the past few years. A number of light sensors have been engineered in bacteria cells and most of them fall into the categories of two-component and one-component systems. Such a sensor toolbox has enabled practices in controlling synthetic circuits at the level of transcription and protein activity which is a major topic in synthetic biology, according to the central dogma. Additionally, engineered light sensors and practices of tuning synthetic circuits have served as a foundation for achieving light based real-time feedback control. Here, we review programming bacteria cells with light, introducing engineered light sensors in bacteria and their applications, including tuning synthetic circuits and achieving feedback controls over microbial cell culture.
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Affiliation(s)
- Zedao Liu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Jizhong Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Jiao Jin
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Zilong Geng
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Qingsheng Qi
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Quanfeng Liang
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
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72
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Cheng RR, Haglund E, Tiee NS, Morcos F, Levine H, Adams JA, Jennings PA, Onuchic JN. Designing bacterial signaling interactions with coevolutionary landscapes. PLoS One 2018; 13:e0201734. [PMID: 30125296 PMCID: PMC6101370 DOI: 10.1371/journal.pone.0201734] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 07/21/2018] [Indexed: 11/19/2022] Open
Abstract
Selecting amino acids to design novel protein-protein interactions that facilitate catalysis is a daunting challenge. We propose that a computational coevolutionary landscape based on sequence analysis alone offers a major advantage over expensive, time-consuming brute-force approaches currently employed. Our coevolutionary landscape allows prediction of single amino acid substitutions that produce functional interactions between non-cognate, interspecies signaling partners. In addition, it can also predict mutations that maintain segregation of signaling pathways across species. Specifically, predictions of phosphotransfer activity between the Escherichia coli histidine kinase EnvZ to the non-cognate receiver Spo0F from Bacillus subtilis were compiled. Twelve mutations designed to enhance, suppress, or have a neutral effect on kinase phosphotransfer activity to a non-cognate partner were selected. We experimentally tested the ability of the kinase to relay phosphate to the respective designed Spo0F receiver proteins against the theoretical predictions. Our key finding is that the coevolutionary landscape theory, with limited structural data, can significantly reduce the search-space for successful prediction of single amino acid substitutions that modulate phosphotransfer between the two-component His-Asp relay partners in a predicted fashion. This combined approach offers significant improvements over large-scale mutations studies currently used for protein engineering and design.
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Affiliation(s)
- Ryan R. Cheng
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- * E-mail: (RRC); (JNO)
| | - Ellinor Haglund
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
| | - Nicholas S. Tiee
- Department of Chemistry & Biochemistry, The University of California, San Diego, California, United States of America
| | - Faruck Morcos
- Department of Biological Sciences, University of Texas at Dallas, Dallas, Texas, United States of America
- Department of Bioengineering, University of Texas at Dallas, Dallas, Texas, United States of America
| | - Herbert Levine
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Bioengineering, Rice University, Houston, Texas, United States of America
- Department of Biosciences, Rice University, Houston, Texas, United States of America
- Department of Physics & Astronomy, Rice University, Houston, Texas, United States of America
| | - Joseph A. Adams
- Department of Pharmacology, The University of California, San Diego, California, United States of America
| | - Patricia A. Jennings
- Department of Chemistry & Biochemistry, The University of California, San Diego, California, United States of America
| | - José N. Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- Department of Biosciences, Rice University, Houston, Texas, United States of America
- Department of Physics & Astronomy, Rice University, Houston, Texas, United States of America
- Department of Chemistry, Rice University, Houston, Texas, United States of America
- * E-mail: (RRC); (JNO)
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73
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Pilizota T, Yang YT. "Do It Yourself" Microbial Cultivation Techniques for Synthetic and Systems Biology: Cheap, Fun, and Flexible. Front Microbiol 2018; 9:1666. [PMID: 30105008 PMCID: PMC6077191 DOI: 10.3389/fmicb.2018.01666] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 07/04/2018] [Indexed: 12/14/2022] Open
Abstract
With the emergence of inexpensive 3D printing technology, open-source platforms for electronic prototyping and single-board computers, "Do it Yourself" (DIY) approaches to the cultivation of microbial cultures are becoming more feasible, user-friendly, and thus wider spread. In this perspective, we survey some of these approaches, as well as add-on solutions to commercial instruments for synthetic and system biology applications. We discuss different cultivation designs, including capabilities and limitations. Our intention is to encourage the reader to consider the DIY solutions. Overall, custom cultivation devices offer controlled growth environments with in-line monitoring of, for example, optical density, fluorescence, pH, and dissolved oxygen, all at affordable prices. Moreover, they offer a great degree of flexibility for different applications and requirements and are fun to design and construct. We include several illustrative examples, such as gaining optogenetic control and adaptive laboratory evolution experiments.
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Affiliation(s)
- Teuta Pilizota
- Centre for Synthetic and Systems Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ya-Tang Yang
- Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
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74
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Abstract
Genetically engineered bacteria have the potential to diagnose and treat a wide range of diseases linked to the gastrointestinal tract, or gut. Such engineered microbes will be less expensive and invasive than current diagnostics and more effective and safe than current therapeutics. Recent advances in synthetic biology have dramatically improved the reliability with which bacteria can be engineered with the sensors, genetic circuits, and output (actuator) genes necessary for diagnostic and therapeutic functions. However, to deploy such bacteria in vivo, researchers must identify appropriate gut-adapted strains and consider performance metrics such as sensor detection thresholds, circuit computation speed, growth rate effects, and the evolutionary stability of engineered genetic systems. Other recent reviews have focused on engineering bacteria to target cancer or genetically modifying the endogenous gut microbiota in situ. Here, we develop a standard approach for engineering "smart probiotics," which both diagnose and treat disease, as well as "diagnostic gut bacteria" and "drug factory probiotics," which perform only the former and latter function, respectively. We focus on the use of cutting-edge synthetic biology tools, gut-specific design considerations, and current and future engineering challenges.
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75
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New opportunities for optimal design of dynamic experiments in systems and synthetic biology. ACTA ACUST UNITED AC 2018. [DOI: 10.1016/j.coisb.2018.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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76
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Choudry U, Heyes DJ, Hardman SJO, Sakuma M, Sazanovich IV, Woodhouse J, De La Mora E, Pedersen MN, Wulff M, Weik M, Schirò G, Scrutton NS. Photochemical Mechanism of an Atypical Algal Phytochrome. Chembiochem 2018; 19:1036-1043. [DOI: 10.1002/cbic.201800016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 11/09/2022]
Affiliation(s)
- Uzma Choudry
- Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Derren J. Heyes
- Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Samantha J. O. Hardman
- Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Michiyo Sakuma
- Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
| | - Igor V. Sazanovich
- Central Laser Facility; Research Complex at Harwell; Science and Technology Facilities Council; Harwell Oxford; Didcot OX11 0QX UK
| | - Joyce Woodhouse
- CNRS; Université Grenoble Alpes; CEA-Institut de Biologie Structurale; Grenoble 38044 France
| | - Eugenio De La Mora
- CNRS; Université Grenoble Alpes; CEA-Institut de Biologie Structurale; Grenoble 38044 France
| | | | - Michael Wulff
- European Synchrotron Radiation Facility; Grenoble 38044 France
| | - Martin Weik
- CNRS; Université Grenoble Alpes; CEA-Institut de Biologie Structurale; Grenoble 38044 France
| | - Giorgio Schirò
- CNRS; Université Grenoble Alpes; CEA-Institut de Biologie Structurale; Grenoble 38044 France
| | - Nigel S. Scrutton
- Manchester Institute of Biotechnology; University of Manchester; 131 Princess Street Manchester M1 7DN UK
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77
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Polesskaya O, Baranova A, Bui S, Kondratev N, Kananykhina E, Nazarenko O, Shapiro T, Nardia FB, Kornienko V, Chandhoke V, Stadler I, Lanzafame R, Myakishev-Rempel M. Optogenetic regulation of transcription. BMC Neurosci 2018; 19:12. [PMID: 29745855 PMCID: PMC5998900 DOI: 10.1186/s12868-018-0411-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Optogenetics has become widely recognized for its success in real-time control of brain neurons by utilizing non-mammalian photosensitive proteins to open or close membrane channels. Here we review a less well known type of optogenetic constructs that employs photosensitive proteins to transduce the signal to regulate gene transcription, and its possible use in medicine. One of the problems with existing gene therapies is that they could remain active indefinitely while not allowing regulated transgene production on demand. Optogenetic regulation of transcription (ORT) could potentially be used to regulate the production of a biological drug in situ, by repeatedly applying light to the tissue, and inducing expression of therapeutic transgenes when needed. Red and near infrared wavelengths, which are capable of penetration into tissues, have potential for therapeutic applications. Existing ORT systems are reviewed herein with these considerations in mind.
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Affiliation(s)
| | - Ancha Baranova
- Research Center for Medical Genetics RAMS, Moscow, Russia.,Center for the Study of Chronic Metabolic and Rare Diseases, School of Systems Biology, George Mason University, Fairfax, VA, USA.,Atlas Biomed Group, Moscow, Russia.,Moscow Institute of Physics and Technology, Dolgoprudny, Russia
| | - Sarah Bui
- Center for the Study of Chronic Metabolic and Rare Diseases, School of Systems Biology, George Mason University, Fairfax, VA, USA
| | | | | | | | | | | | | | - Vikas Chandhoke
- Center for the Study of Chronic Metabolic and Rare Diseases, School of Systems Biology, George Mason University, Fairfax, VA, USA
| | | | | | - Max Myakishev-Rempel
- Localized Therapeutics, LLC, San Diego, CA, USA. .,Vaccine Research Institute of San Diego, San Diego, CA, USA.
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78
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Tomazou M, Barahona M, Polizzi KM, Stan GB. Computational Re-design of Synthetic Genetic Oscillators for Independent Amplitude and Frequency Modulation. Cell Syst 2018; 6:508-520.e5. [PMID: 29680377 DOI: 10.1016/j.cels.2018.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 12/14/2017] [Accepted: 03/19/2018] [Indexed: 01/27/2023]
Abstract
To perform well in biotechnology applications, synthetic genetic oscillators must be engineered to allow independent modulation of amplitude and period. This need is currently unmet. Here, we demonstrate computationally how two classic genetic oscillators, the dual-feedback oscillator and the repressilator, can be re-designed to provide independent control of amplitude and period and improve tunability-that is, a broad dynamic range of periods and amplitudes accessible through the input "dials." Our approach decouples frequency and amplitude modulation by incorporating an orthogonal "sink module" where the key molecular species are channeled for enzymatic degradation. This sink module maintains fast oscillation cycles while alleviating the translational coupling between the oscillator's transcription factors and output. We characterize the behavior of our re-designed oscillators over a broad range of physiologically reasonable parameters, explain why this facilitates broader function and control, and provide general design principles for building synthetic genetic oscillators that are more precisely controllable.
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Affiliation(s)
- Marios Tomazou
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK; Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
| | - Mauricio Barahona
- Department of Mathematics, Imperial College London, London SW7 2AZ, UK; Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
| | - Karen M Polizzi
- Department of Life Sciences, Imperial College London, London SW7 2AZ, UK; Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK
| | - Guy-Bart Stan
- Department of Bioengineering, Imperial College London, London SW7 2AZ, UK; Imperial College Centre for Synthetic Biology, Imperial College London, London SW7 2AZ, UK.
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79
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Hennemann J, Iwasaki RS, Grund TN, Diensthuber RP, Richter F, Möglich A. Optogenetic Control by Pulsed Illumination. Chembiochem 2018; 19:1296-1304. [PMID: 29442428 DOI: 10.1002/cbic.201800030] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Indexed: 12/18/2022]
Abstract
Sensory photoreceptors evoke numerous adaptive responses in nature and serve as light-gated actuators in optogenetics to enable the spatiotemporally precise, reversible, and noninvasive control of cellular events. The output of optogenetic circuits can often be dialed in by varying illumination quality, quantity, and duration. A programmable matrix of light-emitting diodes has been devised to efficiently probe the response of optogenetic systems to intermittently applied light of varying intensity and pulse frequency. Circuits for light-regulated gene expression markedly differed in their responses to pulsed illumination of a single color which sufficed for their sequential triggering. In addition to quantity and quality, the pulse frequency of intermittent light hence provides a further input variable for output control in optogenetics and photobiology. Pulsed illumination schemes allow the reduction of overall light dose and facilitate the multiplexing of several lightdependent actuators and reporters.
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Affiliation(s)
- Julia Hennemann
- Lehrstuhl für Biochemie, Universität Bayreuth, 95447, Bayreuth, Germany
| | - Roman S Iwasaki
- Biophysikalische Chemie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Tamara N Grund
- Lehrstuhl für Biochemie, Universität Bayreuth, 95447, Bayreuth, Germany
| | - Ralph P Diensthuber
- Biophysikalische Chemie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Florian Richter
- Biophysikalische Chemie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
| | - Andreas Möglich
- Lehrstuhl für Biochemie, Universität Bayreuth, 95447, Bayreuth, Germany.,Biophysikalische Chemie, Institut für Biologie, Humboldt-Universität zu Berlin, 10115, Berlin, Germany
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80
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Landry BP, Palanki R, Dyulgyarov N, Hartsough LA, Tabor JJ. Phosphatase activity tunes two-component system sensor detection threshold. Nat Commun 2018; 9:1433. [PMID: 29650958 PMCID: PMC5897336 DOI: 10.1038/s41467-018-03929-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 03/22/2018] [Indexed: 12/22/2022] Open
Abstract
Two-component systems (TCSs) are the largest family of multi-step signal transduction pathways in biology, and a major source of sensors for biotechnology. However, the input concentrations to which biosensors respond are often mismatched with application requirements. Here, we utilize a mathematical model to show that TCS detection thresholds increase with the phosphatase activity of the sensor histidine kinase. We experimentally validate this result in engineered Bacillus subtilis nitrate and E. coli aspartate TCS sensors by tuning their detection threshold up to two orders of magnitude. We go on to apply our TCS tuning method to recently described tetrathionate and thiosulfate sensors by mutating a widely conserved residue previously shown to impact phosphatase activity. Finally, we apply TCS tuning to engineer B. subtilis to sense and report a wide range of fertilizer concentrations in soil. This work will enable the engineering of tailor-made biosensors for diverse synthetic biology applications. Two-component systems are a major family of signal transduction pathways and a rich source of sensors for biotechnology. Here, the authors develop a general method for rationally tuning two-component system input detection thresholds via specific point mutations in sensor histidine kinase proteins.
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Affiliation(s)
- Brian P Landry
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Rohan Palanki
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Nikola Dyulgyarov
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Lucas A Hartsough
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA
| | - Jeffrey J Tabor
- Department of Bioengineering, Rice University, 6100 Main St., Houston, 77005, TX, USA. .,Department of Biosciences, Rice University, 6100 Main St., Houston, 77005, TX, USA.
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81
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Correlating structural and photochemical heterogeneity in cyanobacteriochrome NpR6012g4. Proc Natl Acad Sci U S A 2018; 115:4387-4392. [PMID: 29632180 DOI: 10.1073/pnas.1720682115] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Phytochrome photoreceptors control plant growth, development, and the shade avoidance response that limits crop yield in high-density agricultural plantings. Cyanobacteriochromes (CBCRs) are distantly related photosensory proteins that control cyanobacterial metabolism and behavior in response to light. Photoreceptors in both families reversibly photoconvert between two photostates via photoisomerization of linear tetrapyrrole (bilin) chromophores. Spectroscopic and biochemical studies have demonstrated heterogeneity in both photostates, but the structural basis for such heterogeneity remains unclear. We report solution NMR structures for both photostates of the red/green CBCR NpR6012g4 from Nostoc punctiforme In addition to identifying structural changes accompanying photoconversion, these structures reveal structural heterogeneity for residues Trp655 and Asp657 in the red-absorbing NpR6012g4 dark state, yielding two distinct environments for the phycocyanobilin chromophore. We use site-directed mutagenesis and fluorescence and absorbance spectroscopy to assign an orange-absorbing population in the NpR6012g4 dark state to the minority configuration for Asp657. This population does not undergo full, productive photoconversion, as shown by time-resolved spectroscopy and absorption spectroscopy at cryogenic temperature. Our studies thus elucidate the spectral and photochemical consequences of structural heterogeneity in a member of the phytochrome superfamily, insights that should inform efforts to improve photochemical or fluorescence quantum yields in the phytochrome superfamily.
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82
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Blain-Hartung M, Rockwell NC, Moreno MV, Martin SS, Gan F, Bryant DA, Lagarias JC. Cyanobacteriochrome-based photoswitchable adenylyl cyclases (cPACs) for broad spectrum light regulation of cAMP levels in cells. J Biol Chem 2018; 293:8473-8483. [PMID: 29632072 DOI: 10.1074/jbc.ra118.002258] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 04/02/2018] [Indexed: 12/18/2022] Open
Abstract
Class III adenylyl cyclases generate the ubiquitous second messenger cAMP from ATP often in response to environmental or cellular cues. During evolution, soluble adenylyl cyclase catalytic domains have been repeatedly juxtaposed with signal-input domains to place cAMP synthesis under the control of a wide variety of these environmental and endogenous signals. Adenylyl cyclases with light-sensing domains have proliferated in photosynthetic species depending on light as an energy source, yet are also widespread in nonphotosynthetic species. Among such naturally occurring light sensors, several flavin-based photoactivated adenylyl cyclases (PACs) have been adopted as optogenetic tools to manipulate cellular processes with blue light. In this report, we report the discovery of a cyanobacteriochrome-based photoswitchable adenylyl cyclase (cPAC) from the cyanobacterium Microcoleus sp. PCC 7113. Unlike flavin-dependent PACs, which must thermally decay to be deactivated, cPAC exhibits a bistable photocycle whose adenylyl cyclase could be reversibly activated and inactivated by blue and green light, respectively. Through domain exchange experiments, we also document the ability to extend the wavelength-sensing specificity of cPAC into the near IR. In summary, our work has uncovered a cyanobacteriochrome-based adenylyl cyclase that holds great potential for the design of bistable photoswitchable adenylyl cyclases to fine-tune cAMP-regulated processes in cells, tissues, and whole organisms with light across the visible spectrum and into the near IR.
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Affiliation(s)
- Matthew Blain-Hartung
- From the Department of Molecular and Cellular Biology, University of California, Davis, California 95616
| | - Nathan C Rockwell
- From the Department of Molecular and Cellular Biology, University of California, Davis, California 95616
| | - Marcus V Moreno
- From the Department of Molecular and Cellular Biology, University of California, Davis, California 95616
| | - Shelley S Martin
- From the Department of Molecular and Cellular Biology, University of California, Davis, California 95616
| | - Fei Gan
- the Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Donald A Bryant
- the Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, and.,the Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717
| | - J Clark Lagarias
- From the Department of Molecular and Cellular Biology, University of California, Davis, California 95616,
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83
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Ong NT, Tabor JJ. A Miniaturized Escherichia coli Green Light Sensor with High Dynamic Range. Chembiochem 2018; 19:1255-1258. [PMID: 29420866 DOI: 10.1002/cbic.201800007] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2018] [Indexed: 12/16/2022]
Abstract
Genetically engineered photoreceptors enable unrivaled control over gene expression. Previously, we ported the Synechocystis PCC 6803 CcaSR two-component system, which is activated by green light and deactivated by red, into Escherichia coli, resulting in a sensor with a sixfold dynamic range. Later, we optimized pathway protein expression levels and the output promoter sequence to decrease transcriptional leakiness and to increase the dynamic range to approximately 120-fold. These CcaSR v 1.0 and v 2.0 systems have been used for precise quantitative, temporal, and spatial control of gene expression for a variety of applications. Recently, other workers deleted two PAS domains of unknown function from the CcaS sensor histidine kinase in a system similar to CcaSR v 1.0. Here we apply these deletions to CcaSR v 2.0, resulting in a v 3.0 light sensor with an output four times less leaky and a dynamic range of nearly 600-fold. We demonstrate that the PAS domain deletions have no deleterious effect on CcaSR green light sensitivity or response dynamics. CcaSR v 3.0 is the best-performing engineered bacterial green light sensor available, and should have broad applications in fundamental and synthetic biology studies.
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Affiliation(s)
- Nicholas T Ong
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX, 77005, USA
| | - Jeffrey J Tabor
- Department of Bioengineering, Rice University, 6100 Main Street, Houston, TX, 77005, USA.,Department of Biosciences, Rice University, 6100 Main Street, Houston, TX, 77005, USA
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84
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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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85
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Abstract
Optogenetics is a technology wherein researchers combine light and genetically engineered photoreceptors to control biological processes with unrivaled precision. Near-infrared (NIR) wavelengths (>700 nm) are desirable optogenetic inputs due to their low phototoxicity and spectral isolation from most photoproteins. The bacteriophytochrome photoreceptor 1 (BphP1), found in several purple photosynthetic bacteria, senses NIR light and activates transcription of photosystem promoters by binding to and inhibiting the transcriptional repressor PpsR2. Here, we examine the response of a library of output promoters to increasing levels of Rhodopseudomonas palustris PpsR2 expression, and we identify that of Bradyrhizobium sp. BTAi1 crtE as the most strongly repressed in Escherichia coli. Next, we optimize Rps. palustris bphP1 and ppsR2 expression in a strain engineered to produce the required chromophore biliverdin IXα in order to demonstrate NIR-activated transcription. Unlike a previously engineered bacterial NIR photoreceptor, our system does not require production of a second messenger, and it exhibits rapid response dynamics. It is also the most red-shifted bacterial optogenetic tool yet reported by approximately 50 nm. Accordingly, our BphP1-PpsR2 system has numerous applications in bacterial optogenetics.
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Affiliation(s)
- Nicholas T. Ong
- Department of Bioengineering, ‡Department of Biosciences, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Evan J. Olson
- Department of Bioengineering, ‡Department of Biosciences, Rice University, 6100
Main Street, Houston, Texas 77005, United States
| | - Jeffrey J. Tabor
- Department of Bioengineering, ‡Department of Biosciences, Rice University, 6100
Main Street, Houston, Texas 77005, United States
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86
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Baumschlager A, Aoki SK, Khammash M. Dynamic Blue Light-Inducible T7 RNA Polymerases (Opto-T7RNAPs) for Precise Spatiotemporal Gene Expression Control. ACS Synth Biol 2017; 6:2157-2167. [PMID: 29045151 DOI: 10.1021/acssynbio.7b00169] [Citation(s) in RCA: 87] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Light has emerged as a control input for biological systems due to its precise spatiotemporal resolution. The limited toolset for light control in bacteria motivated us to develop a light-inducible transcription system that is independent from cellular regulation through the use of an orthogonal RNA polymerase. Here, we present our engineered blue light-responsive T7 RNA polymerases (Opto-T7RNAPs) that show properties such as low leakiness of gene expression in the dark state, high expression strength when induced with blue light, and an inducible range of more than 300-fold. Following optimization of the system to reduce expression variability, we created a variant that returns to the inactive dark state within minutes once the blue light is turned off. This allows for precise dynamic control of gene expression, which is a key aspect for most applications using optogenetic regulation. The regulators, which only require blue light from ordinary light-emitting diodes for induction, were developed and tested in the bacterium Escherichia coli, which is a crucial cell factory for biotechnology due to its fast and inexpensive cultivation and well understood physiology and genetics. Opto-T7RNAP, with minor alterations, should be extendable to other bacterial species as well as eukaryotes such as mammalian cells and yeast in which the T7 RNA polymerase and the light-inducible Vivid regulator have been shown to be functional. We anticipate that our approach will expand the applicability of using light as an inducer for gene expression independent from cellular regulation and allow for a more reliable dynamic control of synthetic and natural gene networks.
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Affiliation(s)
- Armin Baumschlager
- Department of Biosystems
Science and Engineering (D-BSSE), ETH−Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Stephanie K. Aoki
- Department of Biosystems
Science and Engineering (D-BSSE), ETH−Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Mustafa Khammash
- Department of Biosystems
Science and Engineering (D-BSSE), ETH−Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
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87
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Blain-Hartung M, Rockwell NC, Lagarias JC. Light-Regulated Synthesis of Cyclic-di-GMP by a Bidomain Construct of the Cyanobacteriochrome Tlr0924 (SesA) without Stable Dimerization. Biochemistry 2017; 56:6145-6154. [PMID: 29072834 DOI: 10.1021/acs.biochem.7b00734] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Phytochromes and cyanobacteriochromes (CBCRs) use double-bond photoisomerization of their linear tetrapyrrole (bilin) chromophores within cGMP-specific phosphodiesterases/adenylyl cyclases/FhlA (GAF) domain-containing photosensory modules to regulate activity of C-terminal output domains. CBCRs exhibit photocycles that are much more diverse than those of phytochromes and are often found in large modular proteins such as Tlr0924 (SesA), one of three blue light regulators of cell aggregation in the cyanobacterium Thermosynechococcus elongatus. Tlr0924 contains a single bilin-binding GAF domain adjacent to a C-terminal diguanylate cyclase (GGDEF) domain whose catalytic activity requires formation of a dimeric transition state presumably supported by a multidomain extension at its N-terminus. To probe the structural basis of light-mediated signal propagation from the photosensory input domain to a signaling output domain for a representative CBCR, these studies explore the properties of a bidomain GAF-GGDEF construct of Tlr0924 (Tlr0924Δ) that retains light-regulated diguanylate cyclase activity. Surprisingly, circular dichroism spectroscopy and size exclusion chromatography data do not support formation of stable dimers in either the blue-absorbing 15ZPb dark state or the green-absorbing 15EPg photoproduct state of Tlr0924Δ. Analysis of variants containing site-specific mutations reveals that proper signal transmission requires both chromophorylation of the GAF domain and individual residues within the amphipathic linker region between GAF and GGDEF domains. On the basis of these data, we propose a model in which bilin binding and light signals are propagated from the GAF domain via the linker to alter the equilibrium and interconversion dynamics between active and inactive conformations of the GGDEF domain to favor or disfavor formation of catalytically competent dimers.
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Affiliation(s)
- Matthew Blain-Hartung
- Department of Molecular and Cellular Biology, University of California , Davis, California 95616, United States
| | - Nathan C Rockwell
- Department of Molecular and Cellular Biology, University of California , Davis, California 95616, United States
| | - J Clark Lagarias
- Department of Molecular and Cellular Biology, University of California , Davis, California 95616, United States
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88
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Hirose Y, Misawa N, Yonekawa C, Nagao N, Watanabe M, Ikeuchi M, Eki T. Characterization of the genuine type 2 chromatic acclimation in the two Geminocystis cyanobacteria. DNA Res 2017; 24:387-396. [PMID: 28338901 PMCID: PMC5737509 DOI: 10.1093/dnares/dsx011] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 02/22/2017] [Indexed: 01/30/2023] Open
Abstract
Certain cyanobacteria can adjust the wavelengths of light they absorb by remodeling their photosynthetic antenna complex phycobilisome via a process called chromatic acclimation (CA). Although several types of CA have been reported, the diversity of the molecular mechanisms of CA among the cyanobacteria phylum is not fully understood. Here, we characterized the molecular process of CA of Geminocystis sp. strains National Institute of Environmental Studies (NIES)-3708 and NIES-3709. Absorption and fluorescence spectroscopy revealed that both strains dramatically alter their phycoerythrin content in response to green and red light. Whole-genome comparison revealed that the two strains share the typical phycobilisome structure consisting of a central core and peripheral rods, but they differ in the number of rod linkers of phycoerythrin and thus have differing capacity for phycoerythrin accumulation. RNA sequencing analysis suggested that the length of phycoerythrin rods in each phycobilisome is strictly regulated by the green light and red light-sensing CcaS/R system, whereas the total number of phycobilisomes is governed by the excitation-balancing system between phycobilisomes and photosystems. We reclassify the conventional CA types based on the genome information and designate CA of the two strains as genuine type 2, where components of phycoerythrin, but not rod-membrane linker of phycocyanin, are regulated by the CcaS/R system.
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Affiliation(s)
- Yuu Hirose
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan
| | - Naomi Misawa
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan
| | - Chinatsu Yonekawa
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan
| | - Nobuyoshi Nagao
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan
| | - Mai Watanabe
- Department of Life Sciences (Biology), The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Masahiko Ikeuchi
- Department of Life Sciences (Biology), The University of Tokyo, 3-8-1 Komaba, Meguro, Tokyo 153-8902, Japan
| | - Toshihiko Eki
- Department of Environmental and Life Sciences, Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku, Toyohashi, Aichi 441-8580, Japan
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89
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Engineering a riboswitch-based genetic platform for the self-directed evolution of acid-tolerant phenotypes. Nat Commun 2017; 8:411. [PMID: 28871084 PMCID: PMC5583362 DOI: 10.1038/s41467-017-00511-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 07/05/2017] [Indexed: 12/12/2022] Open
Abstract
Environmental pH is a fundamental signal continuously directing the metabolism and behavior of living cells. Programming the precise cellular response toward environmental pH is, therefore, crucial for engineering cells for increasingly sophisticated functions. Herein, we engineer a set of riboswitch-based pH-sensing genetic devices to enable the control of gene expression according to differential environmental pH. We next develop a digital pH-sensing system to utilize the analogue-sensing behavior of these devices for high-resolution recording of host cell exposure to discrete external pH levels. The application of this digital pH-sensing system is demonstrated in a genetic program that autonomously regulated the evolutionary engineering of host cells for improved tolerance to a broad spectrum of organic acids, a valuable phenotype for metabolic engineering and bioremediation applications. Cells are exposed to shifts in environmental pH, which direct their metabolism and behavior. Here the authors design pH-sensing riboswitches to create a gene expression program, digitalize the system to respond to a narrow pH range and apply it to evolve host cells with improved tolerance to a variety of organic acids.
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90
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Engstrom MD, Pfleger BF. Transcription control engineering and applications in synthetic biology. Synth Syst Biotechnol 2017; 2:176-191. [PMID: 29318198 PMCID: PMC5655343 DOI: 10.1016/j.synbio.2017.09.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 09/26/2017] [Accepted: 09/26/2017] [Indexed: 12/18/2022] Open
Abstract
In synthetic biology, researchers assemble biological components in new ways to produce systems with practical applications. One of these practical applications is control of the flow of genetic information (from nucleic acid to protein), a.k.a. gene regulation. Regulation is critical for optimizing protein (and therefore activity) levels and the subsequent levels of metabolites and other cellular properties. The central dogma of molecular biology posits that information flow commences with transcription, and accordingly, regulatory tools targeting transcription have received the most attention in synthetic biology. In this mini-review, we highlight many past successes and summarize the lessons learned in developing tools for controlling transcription. In particular, we focus on engineering studies where promoters and transcription terminators (cis-factors) were directly engineered and/or isolated from DNA libraries. We also review several well-characterized transcription regulators (trans-factors), giving examples of how cis- and trans-acting factors have been combined to create digital and analogue switches for regulating transcription in response to various signals. Last, we provide examples of how engineered transcription control systems have been used in metabolic engineering and more complicated genetic circuits. While most of our mini-review focuses on the well-characterized bacterium Escherichia coli, we also provide several examples of the use of transcription control engineering in non-model organisms. Similar approaches have been applied outside the bacterial kingdom indicating that the lessons learned from bacterial studies may be generalized for other organisms.
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Affiliation(s)
- Michael D. Engstrom
- Genetics-Biotechnology Center, University of Wisconsin-Madison School of Medicine and Public Health, USA
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison College of Engineering, USA
| | - Brian F. Pfleger
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison College of Engineering, USA
- Microbiology Doctoral Training Program, University of Wisconsin-Madison, USA
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91
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Oliinyk OS, Chernov KG, Verkhusha VV. Bacterial Phytochromes, Cyanobacteriochromes and Allophycocyanins as a Source of Near-Infrared Fluorescent Probes. Int J Mol Sci 2017; 18:E1691. [PMID: 28771184 PMCID: PMC5578081 DOI: 10.3390/ijms18081691] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Revised: 07/28/2017] [Accepted: 07/28/2017] [Indexed: 12/21/2022] Open
Abstract
Bacterial photoreceptors absorb light energy and transform it into intracellular signals that regulate metabolism. Bacterial phytochrome photoreceptors (BphPs), some cyanobacteriochromes (CBCRs) and allophycocyanins (APCs) possess the near-infrared (NIR) absorbance spectra that make them promising molecular templates to design NIR fluorescent proteins (FPs) and biosensors for studies in mammalian cells and whole animals. Here, we review structures, photochemical properties and molecular functions of several families of bacterial photoreceptors. We next analyze molecular evolution approaches to develop NIR FPs and biosensors. We then discuss phenotypes of current BphP-based NIR FPs and compare them with FPs derived from CBCRs and APCs. Lastly, we overview imaging applications of NIR FPs in live cells and in vivo. Our review provides guidelines for selection of existing NIR FPs, as well as engineering approaches to develop NIR FPs from the novel natural templates such as CBCRs.
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Affiliation(s)
- Olena S Oliinyk
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland.
| | - Konstantin G Chernov
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland.
| | - Vladislav V Verkhusha
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, 00290 Helsinki, Finland.
- Department of Anatomy and Structural Biology, and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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92
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Samodelov SL, Zurbriggen MD. Quantitatively Understanding Plant Signaling: Novel Theoretical-Experimental Approaches. TRENDS IN PLANT SCIENCE 2017; 22:685-704. [PMID: 28668509 DOI: 10.1016/j.tplants.2017.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2016] [Revised: 05/15/2017] [Accepted: 05/16/2017] [Indexed: 06/07/2023]
Abstract
With the need to respond to and integrate a multitude of external and internal stimuli, plant signaling is highly complex, exhibiting signaling component redundancy and high interconnectedness between individual pathways. We review here novel theoretical-experimental approaches in manipulating plant signaling towards the goal of a comprehensive understanding and targeted quantitative control of plant processes. We highlight approaches taken in the field of synthetic biology used in other systems and discuss their applicability in plants. Finally, we introduce existing tools for the quantitative analysis and monitoring of plant signaling and the integration of experimentally obtained quantitative data into mathematical models. Incorporating principles of synthetic biology into plant sciences more widely will lead this field forward in both fundamental and applied research.
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Affiliation(s)
- Sophia L Samodelov
- Institute of Synthetic Biology and Cluster of Excellence on Plant Sciences (CEPLAS), University of Düsseldorf, Düsseldorf, Germany; Spemann Graduate School of Biology and Medicine (SGBM), University of Freiburg, Freiburg, Germany
| | - Matias D Zurbriggen
- Institute of Synthetic Biology and Cluster of Excellence on Plant Sciences (CEPLAS), University of Düsseldorf, Düsseldorf, Germany.
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93
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Lakatos E, Stumpf MPH. Control mechanisms for stochastic biochemical systems via computation of reachable sets. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160790. [PMID: 28878957 PMCID: PMC5579072 DOI: 10.1098/rsos.160790] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/21/2017] [Indexed: 06/07/2023]
Abstract
Controlling the behaviour of cells by rationally guiding molecular processes is an overarching aim of much of synthetic biology. Molecular processes, however, are notoriously noisy and frequently nonlinear. We present an approach to studying the impact of control measures on motifs of molecular interactions that addresses the problems faced in many biological systems: stochasticity, parameter uncertainty and nonlinearity. We show that our reachability analysis formalism can describe the potential behaviour of biological (naturally evolved as well as engineered) systems, and provides a set of bounds on their dynamics at the level of population statistics: for example, we can obtain the possible ranges of means and variances of mRNA and protein expression levels, even in the presence of uncertainty about model parameters.
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Affiliation(s)
- Eszter Lakatos
- Centre for Integrative Systems Biology and Bioinformatics, Department of Life Sciences, Biosciences, Imperial College London, London SW7 2AZ, UK
| | - Michael P. H. Stumpf
- Centre for Integrative Systems Biology and Bioinformatics, Department of Life Sciences, Biosciences, Imperial College London, London SW7 2AZ, UK
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94
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Fernandez-Rodriguez J, Moser F, Song M, Voigt CA. Engineering RGB color vision into Escherichia coli. Nat Chem Biol 2017; 13:706-708. [PMID: 28530708 DOI: 10.1038/nchembio.2390] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 03/03/2017] [Indexed: 11/09/2022]
Abstract
Optogenetic tools use colored light to rapidly control gene expression in space and time. We designed a genetically encoded system that gives Escherichia coli the ability to distinguish between red, green, and blue (RGB) light and respond by changing gene expression. We use this system to produce 'color photographs' on bacterial culture plates by controlling pigment production and to redirect metabolic flux by expressing CRISPRi guide RNAs.
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Affiliation(s)
- Jesus Fernandez-Rodriguez
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Felix Moser
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Miryoung Song
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Christopher A Voigt
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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95
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Eleftheriou C, Cesca F, Maragliano L, Benfenati F, Maya-Vetencourt JF. Optogenetic Modulation of Intracellular Signalling and Transcription: Focus on Neuronal Plasticity. J Exp Neurosci 2017; 11:1179069517703354. [PMID: 28579827 PMCID: PMC5415353 DOI: 10.1177/1179069517703354] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 12/17/2022] Open
Abstract
Several fields in neuroscience have been revolutionized by the advent of optogenetics, a technique that offers the possibility to modulate neuronal physiology in response to light stimulation. This innovative and far-reaching tool provided unprecedented spatial and temporal resolution to explore the activity of neural circuits underlying cognition and behaviour. With an exponential growth in the discovery and synthesis of new photosensitive actuators capable of modulating neuronal networks function, other fields in biology are experiencing a similar re-evolution. Here, we review the various optogenetic toolboxes developed to influence cellular physiology as well as the diverse ways in which these can be engineered to precisely modulate intracellular signalling and transcription. We also explore the processes required to successfully express and stimulate these photo-actuators in vivo before discussing how such tools can enlighten our understanding of neuronal plasticity at the systems level.
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Affiliation(s)
- Cyril Eleftheriou
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Fabrizia Cesca
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova, Italy.,Department of Experimental Medicine, University of Genova, Genova, Italy
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96
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Light-controlled gene expression in yeast using photocaged Cu 2. J Biotechnol 2017; 258:117-125. [PMID: 28455204 DOI: 10.1016/j.jbiotec.2017.04.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/24/2017] [Accepted: 04/24/2017] [Indexed: 11/21/2022]
Abstract
The manipulation of cellular function, such as the regulation of gene expression, is of great interest to many biotechnological applications and often achieved by the addition of small effector molecules. By combining effector molecules with photolabile protecting groups that mask their biological activity until they are activated by light, precise, yet minimally invasive, photocontrol is enabled. However, applications of this trendsetting technology are limited by the small number of established caged compound-based expression systems. Supported by computational chemistry, we used the versatile photolabile chelator DMNP-EDTA, long-established in neurobiology for photolytic Ca2+ release, to control Cu2+ release upon specific UV-A irradiation. This permits light-mediated control over the widely used Cu2+-inducible pCUP1 promoter from S. cerevisiae and thus constitutes the first example of a caged metal ion to regulate recombinant gene expression. We screened our novel DMNP-EDTA-Cu system for best induction time and expression level of eYFP with a high-throughput online monitoring system equipped with an LED array for individual illumination of every single well. Thereby, we realized a minimally invasive, easy-to-control, parallel and automated optical expression regulation via caged Cu2+ allowing temporal and quantitative control as a beneficial alternative to conventional induction via pipetting CuCl2 as effector molecule.
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97
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Olson EJ, Tzouanas CN, Tabor JJ. A photoconversion model for full spectral programming and multiplexing of optogenetic systems. Mol Syst Biol 2017; 13:926. [PMID: 28438832 PMCID: PMC5408778 DOI: 10.15252/msb.20167456] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Optogenetics combines externally applied light signals and genetically engineered photoreceptors to control cellular processes with unmatched precision. Here, we develop a mathematical model of wavelength‐ and intensity‐dependent photoconversion, signaling, and output gene expression for our two previously engineered light‐sensing Escherichia coli two‐component systems. To parameterize the model, we develop a simple set of spectral and dynamical calibration experiments using our recent open‐source “Light Plate Apparatus” device. In principle, the parameterized model should predict the gene expression response to any time‐varying signal from any mixture of light sources with known spectra. We validate this capability experimentally using a suite of challenging light sources and signals very different from those used during the parameterization process. Furthermore, we use the model to compensate for significant spectral cross‐reactivity inherent to the two sensors in order to develop a new method for programming two simultaneous and independent gene expression signals within the same cell. Our optogenetic multiplexing method will enable powerful new interrogations of how metabolic, signaling, and decision‐making pathways integrate multiple input signals.
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Affiliation(s)
- Evan J Olson
- Graduate Program in Applied Physics, Rice University, Houston, TX, USA
| | | | - Jeffrey J Tabor
- Department of Bioengineering, Rice University, Houston, TX, USA .,Department of Biosciences, Rice University, Houston, TX, USA
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98
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Mühlhäuser WW, Fischer A, Weber W, Radziwill G. Optogenetics - Bringing light into the darkness of mammalian signal transduction. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:280-292. [DOI: 10.1016/j.bbamcr.2016.11.009] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 11/04/2016] [Accepted: 11/10/2016] [Indexed: 01/01/2023]
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99
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Construction of a Miniaturized Chromatic Acclimation Sensor from Cyanobacteria with Reversed Response to a Light Signal. Sci Rep 2016; 6:37595. [PMID: 27883080 PMCID: PMC5121610 DOI: 10.1038/srep37595] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 10/27/2016] [Indexed: 12/26/2022] Open
Abstract
Cyanobacteria harbor unique photoreceptors, designated as cyanobacteriochromes (CBCRs). In this study, we attempted to engineer the chromatic acclimation sensor CcaS, a CBCR derived from the cyanobacterium Synechocystis sp. PCC 6803. The wild-type CcaS induces gene expression under green light illumination and represses it under red light illumination. We focused on the domain structure of CcaS, which consists of an N-terminal transmembrane helix; a GAF domain, which serves as the sensor domain; a linker region (L1); two PAS domains; a second linker region (L2); and a C-terminal histidine kinase (HK) domain. Truncated versions of the photoreceptor were constructed by removing the L1 linker region and the two PAS domains, and fusing the GAF and HK domains with a truncated linker region. Thus constructed “miniaturized CcaSs” were grouped into four distinct categories according to their responses toward green and red light illumination, with some showing improved gene regulation compared to the wild type. Remarkably, one of the miniaturized CcaSs induced gene expression under red light and repressed it under green light, a reversed response to the light signal compared to wild type CcaS. These characteristics of engineered photoreceptors were discussed by analyzing the CcaS structural model.
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100
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An open-hardware platform for optogenetics and photobiology. Sci Rep 2016; 6:35363. [PMID: 27805047 PMCID: PMC5096413 DOI: 10.1038/srep35363] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 09/28/2016] [Indexed: 12/27/2022] Open
Abstract
In optogenetics, researchers use light and genetically encoded photoreceptors to control biological processes with unmatched precision. However, outside of neuroscience, the impact of optogenetics has been limited by a lack of user-friendly, flexible, accessible hardware. Here, we engineer the Light Plate Apparatus (LPA), a device that can deliver two independent 310 to 1550 nm light signals to each well of a 24-well plate with intensity control over three orders of magnitude and millisecond resolution. Signals are programmed using an intuitive web tool named Iris. All components can be purchased for under $400 and the device can be assembled and calibrated by a non-expert in one day. We use the LPA to precisely control gene expression from blue, green, and red light responsive optogenetic tools in bacteria, yeast, and mammalian cells and simplify the entrainment of cyanobacterial circadian rhythm. The LPA dramatically reduces the entry barrier to optogenetics and photobiology experiments.
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