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A bio-syncretic phototransistor based on optogenetically engineered living cells. Biosens Bioelectron 2021; 178:113050. [PMID: 33548650 DOI: 10.1016/j.bios.2021.113050] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/22/2021] [Accepted: 01/25/2021] [Indexed: 02/07/2023]
Abstract
Human eyes rely on photosensitive receptors to convert light intensity into action potentials for visual perception, and thus bio-inspired photodetectors with bioengineered photoresponsive elements for visual prostheses have received considerable attention by virtue of superior biological functionality and better biocompatibility. However, the current bioengieered photodetectors based on biological elements face a lot of challenges such as slow response time and lack of effective detection of weak bioelectrical signals, resulting in difficulty to perform imaging. Here, we report a human eye-inspired phototransistor by integrating optogenetically engineered living cells and a graphene-based transistor. The living cells, engineered with photosensitive ion channels, channelrhodopsin-2 (ChR2), and thus endowed with the capability of transducing light intensity into bioelectrical signals, are coupled with the graphene layer of the transistor and can regulate the transistor's output. The results show that the photosensitive ion channels enable the phototransistor to output stronger photoelectrical currents with relatively fast response (~25 ms) and wider dynamic range, and demonstrate the transistor owns optical and biological gating with a significant large on/off ratio of 197.5 and high responsivity of 1.37 mA W-1. An artificial imaging system, which mimics the pathway of human visual information transmission from the retina through the lateral geniculate nucleus to the visual cortex, is constructed with the transistor and demonstrate the feasibility of imaging using the bioengineered cells. This work shows a potential that optogenetically engineered cells can be used to develop novel visual prostheses and paves a new avenue for engineering bio-syncretic sensing devices.
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52
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Wu J, Dellal D, Wasserman S. Prokaryote playhouse: A low-cost, laser-cut acrylic incubator for optogenetic bacterial culture. HARDWAREX 2021; 9:e00184. [PMID: 35492052 PMCID: PMC9041274 DOI: 10.1016/j.ohx.2021.e00184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/03/2021] [Accepted: 02/21/2021] [Indexed: 06/14/2023]
Abstract
Bacterial photography is a printing technique that replaces conventional photochemistry with a living film of engineered Escherichia coli. Many biology teaching labs have adopted monochrome bacterial photography because it offers a captivating playground for illustrating central concepts and lab techniques in biological engineering, particularly in the fields of synthetic biology and optogenetics. Recent improvements have increased the number of color channels from one to three. A key practical challenge in three-color printing is to expose a Petri dish loaded with engineered bacteria to a trichromatic image while maintaining it at 37 °C. Prokaryote Playhouse is a compact, inexpensive, open-source, benchtop incubator for light-sensitive bacterial cultures that makes bacterial photography and similar bacterial optogenetic methods more accessible to teaching labs, makerspaces, and research labs. The system includes a laser-cut, light-tight enclosure; digital thermostat; heated sample shelf; single-board computer; and miniature projector. We built a fleet of Prokaryote Playhouses that students have used to produce hundreds of bacterial photographs in a wide range of educational experiences, ranging from a four-hour introduction to synthetic biology and wet lab techniques to a six-week exploratory class for first-year students at MIT.
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Affiliation(s)
- Jin Wu
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
- Department of System Design and Management, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - David Dellal
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Steven Wasserman
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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53
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Yim SS, McBee RM, Song AM, Huang Y, Sheth RU, Wang HH. Robust direct digital-to-biological data storage in living cells. Nat Chem Biol 2021; 17:246-253. [PMID: 33432236 PMCID: PMC7904632 DOI: 10.1038/s41589-020-00711-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 10/30/2020] [Accepted: 11/12/2020] [Indexed: 02/06/2023]
Abstract
DNA has been the predominant information storage medium for biology and holds great promise as a next-generation high-density data medium in the digital era. Currently, the vast majority of DNA-based data storage approaches rely on in vitro DNA synthesis. As such, there are limited methods to encode digital data into the chromosomes of living cells in a single step. Here, we describe a new electrogenetic framework for direct storage of digital data in living cells. Using an engineered redox-responsive CRISPR adaptation system, we encoded binary data in 3-bit units into CRISPR arrays of bacterial cells by electrical stimulation. We demonstrate multiplex data encoding into barcoded cell populations to yield meaningful information storage and capacity up to 72 bits, which can be maintained over many generations in natural open environments. This work establishes a direct digital-to-biological data storage framework and advances our capacity for information exchange between silicon- and carbon-based entities.
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Affiliation(s)
- Sung Sun Yim
- Department of Systems Biology, Columbia University, New York, NY, USA
| | - Ross M McBee
- Department of Systems Biology, Columbia University, New York, NY, USA
- Department of Biological Sciences, Columbia University, New York, NY, USA
| | - Alan M Song
- Department of Systems Biology, Columbia University, New York, NY, USA
| | - Yiming Huang
- Department of Systems Biology, Columbia University, New York, NY, USA
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University, New York, NY, USA
| | - Ravi U Sheth
- Department of Systems Biology, Columbia University, New York, NY, USA
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University, New York, NY, USA
| | - Harris H Wang
- Department of Systems Biology, Columbia University, New York, NY, USA.
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA.
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54
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Shi Y, Hu X, Cui J, Cui L, Huang J, Ma X, Jiang T, Yao X, Lan F, Li J, Bi Z, Li J, Wang Y, Fu H, Wang J, Lin Y, Bai J, Guo X, Tu L, Xu J. Clinical data mining on network of symptom and index and correlation of tongue-pulse data in fatigue population. BMC Med Inform Decis Mak 2021; 21:72. [PMID: 33627103 PMCID: PMC7905588 DOI: 10.1186/s12911-021-01410-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 01/28/2021] [Indexed: 12/19/2022] Open
Abstract
Background Fatigue is a kind of non-specific symptom, which occurs widely in sub-health and various diseases. It is closely related to people's physical and mental health. Due to the lack of objective diagnostic criteria, it is often neglected in clinical diagnosis, especially in the early stage of disease. Many clinical practices and researches have shown that tongue and pulse conditions reflect the body's overall state. Establishing an objective evaluation method for diagnosing disease fatigue and non-disease fatigue by combining clinical symptom, index, and tongue and pulse data is of great significance for clinical treatment timely and effectively. Methods In this study, 2632 physical examination population were divided into healthy controls, sub-health fatigue group, and disease fatigue group. Complex network technology was used to screen out core symptoms and Western medicine indexes of sub-health fatigue and disease fatigue population. Pajek software was used to construct core symptom/index network and core symptom-index combined network. Simultaneously, canonical correlation analysis was used to analyze the objective tongue and pulse data between the two groups of fatigue population and analyze the distribution of tongue and pulse data. Results Some similarities were found in the core symptoms of sub-health fatigue and disease fatigue population, but with different node importance. The node-importance difference indicated that the diagnostic contribution rate of the same symptom to the two groups was different. The canonical correlation coefficient of tongue and pulse data in the disease fatigue group was 0.42 (P < 0.05), on the contrast, correlation analysis of tongue and pulse in the sub-health fatigue group showed no statistical significance. Conclusions The complex network technology was suitable for correlation analysis of symptoms and indexes in fatigue population, and tongue and pulse data had a certain diagnostic contribution to the classification of fatigue population.
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Affiliation(s)
- Yulin Shi
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xiaojuan Hu
- Shanghai Innovation Center of TCM Health Service, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Ji Cui
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Longtao Cui
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jingbin Huang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xuxiang Ma
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Tao Jiang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xinghua Yao
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Fang Lan
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jun Li
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Zijuan Bi
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jiacai Li
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Yu Wang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Hongyuan Fu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jue Wang
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Yanting Lin
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Jingxuan Bai
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Xiaojing Guo
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China
| | - Liping Tu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China.
| | - Jiatuo Xu
- Basic Medical College, Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong, Shanghai, China.
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Phytochromes and Cyanobacteriochromes: Photoreceptor Molecules Incorporating a Linear Tetrapyrrole Chromophore. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1293:167-187. [PMID: 33398813 DOI: 10.1007/978-981-15-8763-4_10] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
In this chapter, we summarize the molecular mechanisms of the linear tetrapyrrole-binding photoreceptors, phytochromes, and cyanobacteriochromes. We especially focus on the color-tuning mechanisms and conformational changes during the photoconversion process. Furthermore, we introduce current status of development of the optogenetic tools based on these molecules. Huge repertoire of these photoreceptors with diverse spectral properties would contribute to development of multiplex optogenetic regulation. Among them, the photoreceptors incorporating the biliverdin IXα chromophore is advantageous for in vivo optogenetics because this is intrinsic in the mammalian cells, and absorbs far-red light penetrating into deep mammalian tissues.
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56
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Living materials fabricated via gradient mineralization of light-inducible biofilms. Nat Chem Biol 2020; 17:351-359. [PMID: 33349707 DOI: 10.1038/s41589-020-00697-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 10/15/2020] [Indexed: 11/08/2022]
Abstract
Living organisms have evolved sophisticated cell-mediated biomineralization mechanisms to build structurally ordered, environmentally adaptive composite materials. Despite advances in biomimetic mineralization research, it remains difficult to produce mineralized composites that integrate the structural features and 'living' attributes of their natural counterparts. Here, inspired by natural graded materials, we developed living patterned and gradient composites by coupling light-inducible bacterial biofilm formation with biomimetic hydroxyapatite (HA) mineralization. We showed that both the location and the degree of mineralization could be regulated by tailoring functional biofilm growth with spatial and biomass density control. The cells in the composites remained viable and could sense and respond to environmental signals. Additionally, the composites exhibited a maximum 15-fold increase in Young's modulus after mineralization and could be applied to repair damage in a spatially controlled manner. Beyond insights into the mechanism of formation of natural graded composites, our study provides a viable means of fabricating living composites with dynamic responsiveness and environmental adaptability.
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57
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Lee M, Woo HM. A Logic NAND Gate for Controlling Gene Expression in a Circadian Rhythm in Cyanobacteria. ACS Synth Biol 2020; 9:3210-3216. [PMID: 33263998 DOI: 10.1021/acssynbio.0c00455] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To enable circadian control of gene expression in cyanobacteria, we constructed a genetic logic gate (NAND) using orthogonal promoters via modular CRISPR interference. The NAND gates were tested in Synechococcus elongatus PCC 7942 using a fluorescent reporter. The NAND gate dynamics were characterized based on the affinity of the dCas9 complex to the output element. Upon connecting tight gene repressions with the circadian promoter (the purF gene; peak expression at dawn), inversed peak expressions were obtained as an output of the NAND gate although the retroactivities were shown in the ON and OFF states. A dark-responsive genetic element of the NAND gate was also expanded to an AND gate in S. elongatus PCC 7942. These cyanobacterial NAND and AND gates could facilitate the control of gene expressions in dynamic metabolic engineering technologies, thereby enabling the cyanobacteria to serve as biosolar cell factories.
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Affiliation(s)
- Mieun Lee
- Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
| | - Han Min Woo
- Department of Food Science and Biotechnology, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
- BioFoundry Research Center, Institute of Biotechnology and Bioengineering, Sungkyunkwan University (SKKU), 2066 Seobu-ro, Jangan-gu, Suwon 16419, Republic of Korea
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58
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Hartsough LA, Park M, Kotlajich MV, Lazar JT, Han B, Lin CCJ, Musteata E, Gambill L, Wang MC, Tabor JJ. Optogenetic control of gut bacterial metabolism to promote longevity. eLife 2020; 9:56849. [PMID: 33325823 PMCID: PMC7744093 DOI: 10.7554/elife.56849] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Accepted: 12/07/2020] [Indexed: 12/21/2022] Open
Abstract
Gut microbial metabolism is associated with host longevity. However, because it requires direct manipulation of microbial metabolism in situ, establishing a causal link between these two processes remains challenging. We demonstrate an optogenetic method to control gene expression and metabolite production from bacteria residing in the host gut. We genetically engineer an Escherichia coli strain that secretes colanic acid (CA) under the quantitative control of light. Using this optogenetically-controlled strain to induce CA production directly in the Caenorhabditis elegans gut, we reveal the local effect of CA in protecting intestinal mitochondria from stress-induced hyper-fragmentation. We also demonstrate that the lifespan-extending effect of this strain is positively correlated with the intensity of green light, indicating a dose-dependent CA benefit on the host. Thus, optogenetics can be used to achieve quantitative and temporal control of gut bacterial metabolism in order to reveal its local and systemic effects on host health and aging.
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Affiliation(s)
| | | | | | - John Tyler Lazar
- Department of Chemical and Biomolecular Engineering, Houston, United States
| | - Bing Han
- Huffington Center on Aging, Houston, United States
| | - Chih-Chun J Lin
- Huffington Center on Aging, Houston, United States.,Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, United States
| | - Elena Musteata
- Systems, Synthetic, and Physical Biology Program, Rice University, Houston, United States
| | - Lauren Gambill
- Systems, Synthetic, and Physical Biology Program, Rice University, Houston, United States
| | - Meng C Wang
- Huffington Center on Aging, Houston, United States.,Department of Molecular & Human Genetics, Baylor College of Medicine, Houston, United States.,Howard Hughes Medical Institute, Houston, United States
| | - Jeffrey J Tabor
- Department of Bioengineering, Houston, United States.,Systems, Synthetic, and Physical Biology Program, Rice University, Houston, United States.,Department of Biosciences, Houston, United States
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59
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Santos-Moreno J, Schaerli Y. CRISPR-based gene expression control for synthetic gene circuits. Biochem Soc Trans 2020; 48:1979-1993. [PMID: 32964920 PMCID: PMC7609024 DOI: 10.1042/bst20200020] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 08/27/2020] [Accepted: 08/28/2020] [Indexed: 12/22/2022]
Abstract
Synthetic gene circuits allow us to govern cell behavior in a programmable manner, which is central to almost any application aiming to harness engineered living cells for user-defined tasks. Transcription factors (TFs) constitute the 'classic' tool for synthetic circuit construction but some of their inherent constraints, such as insufficient modularity, orthogonality and programmability, limit progress in such forward-engineering endeavors. Here we review how CRISPR (clustered regularly interspaced short palindromic repeats) technology offers new and powerful possibilities for synthetic circuit design. CRISPR systems offer superior characteristics over TFs in many aspects relevant to a modular, predictable and standardized circuit design. Thus, the choice of CRISPR technology as a framework for synthetic circuit design constitutes a valid alternative to complement or replace TFs in synthetic circuits and promises the realization of more ambitious designs.
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Affiliation(s)
- Javier Santos-Moreno
- Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
| | - Yolanda Schaerli
- Department of Fundamental Microbiology, University of Lausanne, Biophore Building, 1015 Lausanne, Switzerland
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60
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Jenkins AJ, Gottlieb SM, Chang CW, Kim PW, Hayer RJ, Hanke SJ, Martin SS, Lagarias JC, Larsen DS. Conservation and Diversity in the Primary Reverse Photodynamics of the Canonical Red/Green Cyanobacteriochrome Family. Biochemistry 2020; 59:4015-4028. [PMID: 33021375 DOI: 10.1021/acs.biochem.0c00454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this report, we compare the femtosecond to nanosecond primary reverse photodynamics (15EPg → 15ZPr) of eight tetrapyrrole binding photoswitching cyanobacteriochromes in the canonical red/green family from the cyanobacterium Nostoc punctiforme. Three characteristic classes were identified on the basis of the diversity of excited-state and ground-state properties, including the lifetime, photocycle initiation quantum yield, photointermediate stability, spectra, and temporal properties. We observed a correlation between the excited-state lifetime and peak wavelength of the electronic absorption spectrum with higher-energy-absorbing representatives exhibiting both faster excited-state decay times and higher photoisomerization quantum yields. The latter was attributed to both an increased number of structural restraints and differences in H-bonding networks that facilitate photoisomerization. All three classes exhibited primary Lumi-Go intermediates, with class II and III representatives evolving to a secondary Meta-G photointermediate. Class II Meta-GR intermediates were orange absorbing, whereas class III Meta-G had structurally relaxed, red-absorbing chromophores that resemble their dark-adapted 15ZPr states. Differences in the reverse and forward reaction mechanisms are discussed within the context of structural constraints.
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Affiliation(s)
- Adam J Jenkins
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Sean Marc Gottlieb
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Che-Wei Chang
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Peter W Kim
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Randeep J Hayer
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Samuel J Hanke
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Shelley S Martin
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - J Clark Lagarias
- Department of Molecular and Cellular Biology, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
| | - Delmar S Larsen
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, California 95616, United States
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Carrasco-López C, García-Echauri SA, Kichuk T, Avalos JL. Optogenetics and biosensors set the stage for metabolic cybergenetics. Curr Opin Biotechnol 2020; 65:296-309. [DOI: 10.1016/j.copbio.2020.07.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 07/23/2020] [Accepted: 07/25/2020] [Indexed: 12/17/2022]
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Abstract
The ability to detect disease early and deliver precision therapy would be transformative for the treatment of human illnesses. To achieve these goals, biosensors that can pinpoint when and where diseases emerge are needed. Rapid advances in synthetic biology are enabling us to exploit the information-processing abilities of living cells to diagnose disease and then treat it in a controlled fashion. For example, living sensors could be designed to precisely sense disease biomarkers, such as by-products of inflammation, and to respond by delivering targeted therapeutics in situ. Here, we provide an overview of ongoing efforts in microbial biosensor design, highlight translational opportunities, and discuss challenges for enabling sense-and-respond precision medicines.
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Affiliation(s)
- Maria Eugenia Inda
- MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Timothy K. Lu
- MIT Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Research Laboratory of Electronics, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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63
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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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64
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Park Y, Espah Borujeni A, Gorochowski TE, Shin J, Voigt CA. Precision design of stable genetic circuits carried in highly-insulated E. coli genomic landing pads. Mol Syst Biol 2020; 16:e9584. [PMID: 32812710 PMCID: PMC7436927 DOI: 10.15252/msb.20209584] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 07/07/2020] [Accepted: 07/22/2020] [Indexed: 01/02/2023] Open
Abstract
Genetic circuits have many applications, from guiding living therapeutics to ordering process in a bioreactor, but to be useful they have to be genetically stable and not hinder the host. Encoding circuits in the genome reduces burden, but this decreases performance and can interfere with native transcription. We have designed genomic landing pads in Escherichia coli at high-expression sites, flanked by ultrastrong double terminators. DNA payloads >8 kb are targeted to the landing pads using phage integrases. One landing pad is dedicated to carrying a sensor array, and two are used to carry genetic circuits. NOT/NOR gates based on repressors are optimized for the genome and characterized in the landing pads. These data are used, in conjunction with design automation software (Cello 2.0), to design circuits that perform quantitatively as predicted. These circuits require fourfold less RNA polymerase than when carried on a plasmid and are stable for weeks in a recA+ strain without selection. This approach enables the design of synthetic regulatory networks to guide cells in environments or for applications where plasmid use is infeasible.
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Affiliation(s)
- Yongjin Park
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Amin Espah Borujeni
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Thomas E Gorochowski
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
- Broad Institute of MIT and HarvardCambridgeMAUSA
| | - Jonghyeon Shin
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
| | - Christopher A Voigt
- Synthetic Biology CenterDepartment of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMAUSA
- Broad Institute of MIT and HarvardCambridgeMAUSA
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65
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Hossain A, Lopez E, Halper SM, Cetnar DP, Reis AC, Strickland D, Klavins E, Salis HM. Automated design of thousands of nonrepetitive parts for engineering stable genetic systems. Nat Biotechnol 2020; 38:1466-1475. [PMID: 32661437 DOI: 10.1038/s41587-020-0584-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 05/31/2020] [Indexed: 01/08/2023]
Abstract
Engineered genetic systems are prone to failure when their genetic parts contain repetitive sequences. Designing many nonrepetitive genetic parts with desired functionalities remains a difficult challenge with high computational complexity. To overcome this challenge, we developed the Nonrepetitive Parts Calculator to rapidly generate thousands of highly nonrepetitive genetic parts from specified design constraints, including promoters, ribosome-binding sites and terminators. As a demonstration, we designed and experimentally characterized 4,350 nonrepetitive bacterial promoters with transcription rates that varied across a 820,000-fold range, and 1,722 highly nonrepetitive yeast promoters with transcription rates that varied across a 25,000-fold range. We applied machine learning to explain how specific interactions controlled the promoters' transcription rates. We also show that using nonrepetitive genetic parts substantially reduces homologous recombination, resulting in greater genetic stability.
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Affiliation(s)
- Ayaan Hossain
- Bioinformatics and Genomics, Pennsylvania State University, University Park, PA, USA
| | - Eriberto Lopez
- Department of Electrical & Computer Engineering, University of Washington, Seattle, WA, USA
| | - Sean M Halper
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, USA
| | - Daniel P Cetnar
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, USA
| | - Alexander C Reis
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA, USA
| | - Devin Strickland
- Department of Electrical & Computer Engineering, University of Washington, Seattle, WA, USA
| | - Eric Klavins
- Department of Electrical & Computer Engineering, University of Washington, Seattle, WA, USA
| | - Howard M Salis
- Bioinformatics and Genomics, Pennsylvania State University, University Park, PA, USA. .,Department of Chemical Engineering, Pennsylvania State University, University Park, PA, USA. .,Department of Biological Engineering, Pennsylvania State University, University Park, PA, USA. .,Department of Biomedical Engineering, Pennsylvania State University, University Park, PA, USA.
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66
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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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67
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Modulation of Response Regulator CheY Reaction Kinetics by Two Variable Residues That Affect Conformation. J Bacteriol 2020; 202:JB.00089-20. [PMID: 32424010 DOI: 10.1128/jb.00089-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/09/2020] [Indexed: 01/16/2023] Open
Abstract
Microorganisms and plants utilize two-component systems to regulate adaptive responses to changing environmental conditions. Sensor kinases detect stimuli and alter their autophosphorylation activity accordingly. Signal propagation occurs via the transfer of phosphoryl groups from upstream kinases to downstream response regulator proteins. Removal of phosphoryl groups from the response regulator typically resets the system. Members of the same protein family may catalyze phosphorylation and dephosphorylation reactions with different efficiencies, exhibiting rate constants spanning many orders of magnitude to accommodate response time scales from milliseconds to days. We previously found that variable positions one or two residues to the C-terminal side of the conserved Asp phosphorylation site (D+2) or Thr/Ser (T+1/T+2) in response regulators alter reaction kinetics by direct interaction with phosphodonor or phosphoacceptor molecules. Here, we explore the kinetic effects of amino acid substitutions at the two positions immediately C-terminal to the conserved Lys (K+1/K+2) in the model Escherichia coli response regulator CheY. We measured CheY autophosphorylation and autodephosphorylation rate constants for 27 pairs of K+1/K+2 residues that represent 84% of naturally occurring response regulators. Effects on autodephosphorylation were modest, but autophosphorylation rate constants varied by 2 orders of magnitude, suggesting that the K+1/K+2 positions influence reaction kinetics by altering the conformational spectrum sampled by CheY at equilibrium. Additional evidence supporting this indirect mechanism includes the following: the effect on autophosphorylation rate constants is independent of the phosphodonor, the autophosphorylation rate constants and dissociation constants for the phosphoryl group analog BeF3 - are inversely correlated, and the K+1/K+2 positions are distant from the phosphorylation site.IMPORTANCE We have identified five variable positions in response regulators that allow the rate constants of autophosphorylation and autodephosporylation reactions each to be altered over 3 orders of magnitude in CheY. The distributions of variable residue combinations across response regulator subfamilies suggest that distinct mechanisms associated with different variable positions allow reaction rates to be tuned independently during evolution for diverse biological purposes. This knowledge could be used in synthetic-biology applications to adjust the properties (e.g., background noise and response duration) of biosensors and may allow prediction of response regulator reaction kinetics from the primary amino acid sequence.
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68
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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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69
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Perkins ML, Benzinger D, Arcak M, Khammash M. Cell-in-the-loop pattern formation with optogenetically emulated cell-to-cell signaling. Nat Commun 2020; 11:1355. [PMID: 32170129 PMCID: PMC7069979 DOI: 10.1038/s41467-020-15166-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 02/11/2020] [Indexed: 12/22/2022] Open
Abstract
Designing and implementing synthetic biological pattern formation remains challenging due to underlying theoretical complexity as well as the difficulty of engineering multicellular networks biochemically. Here, we introduce a cell-in-the-loop approach where living cells interact through in silico signaling, establishing a new testbed to interrogate theoretical principles when internal cell dynamics are incorporated rather than modeled. We present an easy-to-use theoretical test to predict the emergence of contrasting patterns in gene expression among laterally inhibiting cells. Guided by the theory, we experimentally demonstrate spontaneous checkerboard patterning in an optogenetic setup, where cell-to-cell signaling is emulated with light inputs calculated in silico from real-time gene expression measurements. The scheme successfully produces spontaneous, persistent checkerboard patterns for systems of sixteen patches, in quantitative agreement with theoretical predictions. Our research highlights how tools from dynamical systems theory may inform our understanding of patterning, and illustrates the potential of cell-in-the-loop for engineering synthetic multicellular systems.
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Affiliation(s)
- Melinda Liu Perkins
- Department of Electrical Engineering, University of California, Berkeley, CA, USA.
| | - Dirk Benzinger
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Murat Arcak
- Department of Electrical Engineering, University of California, Berkeley, CA, USA
| | - Mustafa Khammash
- Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland.
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70
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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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71
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Schultenkämper K, Brito LF, Wendisch VF. Impact of CRISPR interference on strain development in biotechnology. Biotechnol Appl Biochem 2020; 67:7-21. [DOI: 10.1002/bab.1901] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 02/13/2020] [Indexed: 12/17/2022]
Affiliation(s)
| | - Luciana F. Brito
- Department of Biotechnology and Food ScienceNTNUNorwegian University of Science and Technology Trondheim Norway
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72
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Kent R, Dixon N. Contemporary Tools for Regulating Gene Expression in Bacteria. Trends Biotechnol 2019; 38:316-333. [PMID: 31679824 DOI: 10.1016/j.tibtech.2019.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
Abstract
Insights from novel mechanistic paradigms in gene expression control have led to the development of new gene expression systems for bioproduction, control, and sensing applications. Coupled with a greater understanding of synthetic burden and modern creative biodesign approaches, contemporary bacterial gene expression tools and systems are emerging that permit fine-tuning of expression, enabling greater predictability and maximisation of specific productivity, while minimising deleterious effects upon cell viability. These advances have been achieved by using a plethora of regulatory tools, operating at all levels of the so-called 'central dogma' of molecular biology. In this review, we discuss these gene regulation tools in the context of their design, prototyping, integration into expression systems, and biotechnological application.
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Affiliation(s)
- Ross Kent
- Manchester Institute of Biotechnology and School of Chemistry, University of Manchester, Manchester, UK
| | - Neil Dixon
- Manchester Institute of Biotechnology and School of Chemistry, University of Manchester, Manchester, UK.
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73
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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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74
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Kim SG, Noh MH, Lim HG, Jang S, Jang S, Koffas MAG, Jung GY. Molecular parts and genetic circuits for metabolic engineering of microorganisms. FEMS Microbiol Lett 2019; 365:5059574. [PMID: 30052915 DOI: 10.1093/femsle/fny187] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 07/24/2018] [Indexed: 12/17/2022] Open
Abstract
Microbial conversion of biomass into value-added biochemicals is a highly sustainable process compared to petroleum-based production. In this regard, microorganisms have been engineered via simple overexpression or deletion of metabolic genes to facilitate the production. However, the producer microorganisms require complex regulatory circuits to maximize productivity and performance. To address this issue, diverse genetic circuits have been developed that allow cells to minimize their metabolic burden, overcome metabolic imbalances and respond to a dynamically changing environment. In this review, we briefly explain the basic strategy for constructing genetic circuits by assembling molecular parts such as input, operation and output modules. Next, we describe recent applications of the circuits in the metabolic engineering of microorganisms to improve biochemical production. Beyond those achievements, genetic circuits will facilitate more innovative approaches to future strain development through mining and engineering new genetic elements and improving the complexity of genetic circuit design.
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Affiliation(s)
- Seong Gyeong Kim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Myung Hyun Noh
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Hyun Gyu Lim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Sungho Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Sungyeon Jang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
| | - Mattheos A G Koffas
- Department of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy 12180, USA
| | - Gyoo Yeol Jung
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang 37673, Korea
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75
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Gao C, Xu P, Ye C, Chen X, Liu L. Genetic Circuit-Assisted Smart Microbial Engineering. Trends Microbiol 2019; 27:1011-1024. [PMID: 31421969 DOI: 10.1016/j.tim.2019.07.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 06/27/2019] [Accepted: 07/19/2019] [Indexed: 12/22/2022]
Abstract
Rapid advances in DNA synthesis, genetic manipulation, and biosensors have greatly improved the ability to engineer microorganisms with complex functions. By accurately integrating quality biosensors and complex genetic circuits, recently emerged smart microorganisms have enabled exciting opportunities for dissecting complex signaling networks and making responses without artificial intervention. However, because of the lack of design principles, developing such smart microorganisms remains challenging. In this review, we propose the concept of smart microbial engineering (SME) and describe the general features of basic SME, including the circuit architecture, components, and design process. We also summarize the latest SME achievements, remaining challenges, and potential solutions in this growing field.
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Affiliation(s)
- Cong Gao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Peng Xu
- Chemical, Biochemical, and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD 21250, USA
| | - Chao Ye
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Xiulai Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China
| | - Liming Liu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, China; National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China.
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76
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Ma X, Liang H, Cui X, Liu Y, Lu H, Ning W, Poon NY, Ho B, Zhou K. A standard for near-scarless plasmid construction using reusable DNA parts. Nat Commun 2019; 10:3294. [PMID: 31337759 PMCID: PMC6650416 DOI: 10.1038/s41467-019-11263-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 07/04/2019] [Indexed: 12/25/2022] Open
Abstract
Here we report GT (Guanin/Thymine) standard (GTS) for plasmid construction under which DNA sequences are defined as two types of standard, reusable parts (fragment and barcode). We develop a technology that can efficiently add any two barcodes to two ends of any fragment without leaving scars in most cases. We can assemble up to seven such barcoded fragments into one plasmid by using one of the existing DNA assembly methods, including CLIVA, Gibson assembly, In-fusion cloning, and restriction enzyme-based methods. Plasmids constructed under GTS can be easily edited, and/or be further assembled into more complex plasmids by using standard DNA oligonucleotides (oligos). Based on 436 plasmids we constructed under GTS, the averaged accuracy of the workflow was 85.9%. GTS can also construct a library of plasmids from a set of fragments and barcodes combinatorically, which has been demonstrated to be useful for optimizing metabolic pathways. Construction of plasmids from multiple fragments often uses customised parts and leaves scars where fragments are joined. Here the authors develop a method for barcoding fragments and constructing plasmids in a scarless manner from a collection of standard parts.
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Affiliation(s)
- Xiaoqiang Ma
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore.,Disruptive & Sustainable Technologies for Agricultural Precision, Singapore-MIT Alliance for Research and Technology, Singapore, 138602, Singapore
| | - Hong Liang
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore.,Disruptive & Sustainable Technologies for Agricultural Precision, Singapore-MIT Alliance for Research and Technology, Singapore, 138602, Singapore
| | - Xiaoyi Cui
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore.,Disruptive & Sustainable Technologies for Agricultural Precision, Singapore-MIT Alliance for Research and Technology, Singapore, 138602, Singapore
| | - Yurou Liu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore.,Disruptive & Sustainable Technologies for Agricultural Precision, Singapore-MIT Alliance for Research and Technology, Singapore, 138602, Singapore
| | - Hongyuan Lu
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore
| | - Wenbo Ning
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore
| | - Nga Yu Poon
- Disruptive & Sustainable Technologies for Agricultural Precision, Singapore-MIT Alliance for Research and Technology, Singapore, 138602, Singapore
| | - Benjamin Ho
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore
| | - Kang Zhou
- Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 119077, Singapore. .,Disruptive & Sustainable Technologies for Agricultural Precision, Singapore-MIT Alliance for Research and Technology, Singapore, 138602, Singapore.
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77
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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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78
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Glaven SM. Bioelectrochemical systems and synthetic biology: more power, more products. Microb Biotechnol 2019; 12:819-823. [PMID: 31264368 PMCID: PMC6680619 DOI: 10.1111/1751-7915.13456] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Affiliation(s)
- Sarah M Glaven
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, DC, USA
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79
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Seok J, Ko YJ, Lee ME, Hyeon JE, Han SO. Systems metabolic engineering of Corynebacterium glutamicum for the bioproduction of biliverdin via protoporphyrin independent pathway. J Biol Eng 2019; 13:28. [PMID: 30976317 PMCID: PMC6441180 DOI: 10.1186/s13036-019-0156-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/14/2019] [Indexed: 11/24/2022] Open
Abstract
Background Biliverdin, a prospective recyclable antioxidant and one of the most important precursors for optogenetics, has received growing attention. Biliverdin is currently produced by oxidation of bilirubin from mammalian bile using chemicals. However, unsustainable procedures of extraction, chemical oxidation, and isomer separation have prompted bio-based production using a microbial cell factory. Results In vitro thermodynamic analysis was performed to show potential candidates of bottleneck enzymes in the pathway to produce biliverdin. Among the candidates, hemA and hemL were overexpressed in Corynebacterium glutamicum to produce heme, precursor of biliverdin. To increase precursor supply, we suggested a novel hemQ-mediated coproporphyrin dependent pathway rather than noted hemN-mediated protoporphyrin dependent pathway in C. glutamicum. After securing precursors, hmuO was overexpressed to pull the carbon flow to produce biliverdin. Through modular optimization using gene rearrangements of hemA, hemL, hemQ, and hmuO, engineered C. glutamicum BV004 produced 11.38 ± 0.47 mg/L of biliverdin at flask scale. Fed-batch fermentations performed in 5 L bioreactor with minimal medium using glucose as a sole carbon source resulted in the accumulation of 68.74 ± 4.97 mg/L of biliverdin, the highest titer to date to the best of our knowledge. Conclusions We developed an eco-friendly microbial cell factory to produce biliverdin using C. glutamicum as a biosystem. Moreover, we suggested that C. glutamicum has the thermodynamically favorable coproporphyrin dependent pathway. This study indicated that C. glutamicum can work as a powerful platform to produce biliverdin as well as heme-related products based on the rational design with in vitro thermodynamic analysis. Electronic supplementary material The online version of this article (10.1186/s13036-019-0156-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Jiho Seok
- 1Department of Biotechnology, Korea University, Seoul, 02841 Republic of Korea
| | - Young Jin Ko
- 1Department of Biotechnology, Korea University, Seoul, 02841 Republic of Korea
| | - Myeong-Eun Lee
- 1Department of Biotechnology, Korea University, Seoul, 02841 Republic of Korea
| | - Jeong Eun Hyeon
- 1Department of Biotechnology, Korea University, Seoul, 02841 Republic of Korea.,2Department of Food Science and Biotechnology, College of Knowledge-Based Services Engineering, Sungshin Women's University, Seoul, 01133 Republic of Korea.,3Department of Food and Nutrition, College of Health & Wellness, Sungshin Women's University, Seoul, 01133 Republic of Korea
| | - Sung Ok Han
- 1Department of Biotechnology, Korea University, Seoul, 02841 Republic of Korea
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80
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Wan X, Marsafari M, Xu P. Engineering metabolite-responsive transcriptional factors to sense small molecules in eukaryotes: current state and perspectives. Microb Cell Fact 2019; 18:61. [PMID: 30914048 PMCID: PMC6434827 DOI: 10.1186/s12934-019-1111-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 03/20/2019] [Indexed: 11/18/2022] Open
Abstract
Nature has evolved exquisite sensing mechanisms to detect cellular and environmental signals surrounding living organisms. These biosensors have been widely used to sense small molecules, detect environmental cues and diagnose disease markers. Metabolic engineers and synthetic biologists have been able to exploit metabolites-responsive transcriptional factors (MRTFs) as basic tools to rewire cell metabolism, reprogram cellular activity as well as boost cell’s productivity. This is commonly achieved by integrating sensor-actuator systems with biocatalytic functions and dynamically allocating cellular resources to drive carbon flux toward the target pathway. Up to date, most of identified MRTFs are derived from bacteria. As an endeavor to advance intelligent biomanufacturing in yeast cell factory, we will summarize the opportunities and challenges to transfer the bacteria-derived MRTFs to expand the small-molecule sensing capability in eukaryotic cells. We will discuss the design principles underlying MRTF-based biosensors in eukaryotic cells, including the choice of reliable reporters and the characterization tools to minimize background noise, strategies to tune the sensor dynamic range, sensitivity and specificity, as well as the criteria to engineer activator and repressor-based biosensors. Due to the physical separation of transcription and protein expression in eukaryotes, we argue that nuclear import/export mechanism of MRTFs across the nuclear membrane plays a critical role in regulating the MRTF sensor dynamics. Precisely-controlled MRTF response will allow us to repurpose the vast majority of transcriptional factors as molecular switches to achieve temporal or spatial gene expression in eukaryotes. Uncovering this knowledge will inform us fundamental design principles to deliver robust cell factories and enable the design of reprogrammable and predictable biological systems for intelligent biomanufacturing, smart therapeutics or precision medicine in the foreseeable future.
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Affiliation(s)
- Xia Wan
- Department of Chemical Biochemical and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD, 21250, USA.,Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan, 430062, Hubei, China.,Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062, Hubei, China
| | - Monireh Marsafari
- Department of Chemical Biochemical and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD, 21250, USA.,Department of Agronomy and Plant Breeding, University of Guilan, Rasht, Islamic Republic of Iran
| | - Peng Xu
- Department of Chemical Biochemical and Environmental Engineering, University of Maryland Baltimore County, Baltimore, MD, 21250, USA.
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81
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Jung K, Fabiani F, Hoyer E, Lassak J. Bacterial transmembrane signalling systems and their engineering for biosensing. Open Biol 2019; 8:rsob.180023. [PMID: 29695618 PMCID: PMC5936718 DOI: 10.1098/rsob.180023] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/03/2018] [Indexed: 12/27/2022] Open
Abstract
Every living cell possesses numerous transmembrane signalling systems that receive chemical and physical stimuli from the environment and transduce this information into an intracellular signal that triggers some form of cellular response. As unicellular organisms, bacteria require these systems for survival in rapidly changing environments. The receptors themselves act as ‘sensory organs’, while subsequent signalling circuits can be regarded as forming a ‘neural network’ that is involved in decision making, adaptation and ultimately in ensuring survival. Bacteria serve as useful biosensors in industry and clinical diagnostics, in addition to producing drugs for therapeutic purposes. Therefore, there is a great demand for engineered bacterial strains that contain transmembrane signalling systems with high molecular specificity, sensitivity and dose dependency. In this review, we address the complexity of transmembrane signalling systems and discuss principles to rewire receptors and their signalling outputs.
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Affiliation(s)
- Kirsten Jung
- Munich Center for Integrated Protein Science (CiPSM) at the Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Florian Fabiani
- Munich Center for Integrated Protein Science (CiPSM) at the Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Elisabeth Hoyer
- Munich Center for Integrated Protein Science (CiPSM) at the Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Jürgen Lassak
- Munich Center for Integrated Protein Science (CiPSM) at the Department of Biology I, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
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82
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Sankaran S, Becker J, Wittmann C, Del Campo A. Optoregulated Drug Release from an Engineered Living Material: Self-Replenishing Drug Depots for Long-Term, Light-Regulated Delivery. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2019; 15:e1804717. [PMID: 30589209 DOI: 10.1002/smll.201804717] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Revised: 11/30/2018] [Indexed: 06/09/2023]
Abstract
On-demand and long-term delivery of drugs are common requirements in many therapeutic applications, not easy to be solved with available smart polymers for drug encapsulation. This work presents a fundamentally different concept to address such scenarios using a self-replenishing and optogenetically controlled living material. It consists of a hydrogel containing an active endotoxin-free Escherichia coli strain. The bacteria are metabolically and optogenetically engineered to secrete the antimicrobial and antitumoral drug deoxyviolacein in a light-regulated manner. The permeable hydrogel matrix sustains a viable and functional bacterial population and permits diffusion and delivery of the synthesized drug to the surrounding medium at quantities regulated by light dose. Using a focused light beam, the site for synthesis and delivery of the drug can be freely defined. The living material is shown to maintain considerable levels of drug production and release for at least 42 days. These results prove the potential and flexibility that living materials containing engineered bacteria can offer for advanced therapeutic applications.
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Affiliation(s)
| | - Judith Becker
- Institute of Systems Biotechnology, Saarland University, 66123, Saarbrücken, Germany
| | - Christoph Wittmann
- Institute of Systems Biotechnology, Saarland University, 66123, Saarbrücken, Germany
| | - Aránzazu Del Campo
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany
- Chemistry Department, Saarland University, 66123, Saarbrücken, Germany
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83
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Tei M, Perkins ML, Hsia J, Arcak M, Arkin AP. Designing Spatially Distributed Gene Regulatory Networks To Elicit Contrasting Patterns. ACS Synth Biol 2019; 8:119-126. [PMID: 30540439 PMCID: PMC6343107 DOI: 10.1021/acssynbio.8b00377] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Indexed: 01/08/2023]
Abstract
Pattern formation and differential interactions are important for microbial consortia to divide labor and perform complex functions. To obtain further insight into such interactions, we present a computational method for simulating physically separated microbial colonies, each implementing different gene regulatory networks. We validate our theory by experimentally demonstrating control over gene expression patterns in a diffusion-mediated lateral inhibition circuit. We highlight the importance of spatial arrangement as a control knob for modulating system behavior. Our systematic approach provides a foundation for future applications that require understanding and engineering of multistrain microbial communities for sophisticated, synergistic functions.
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Affiliation(s)
- Mika Tei
- The
UC Berkeley−UCSF Graduate Program in Bioengineering, University of California − Berkeley, Berkeley, California 94704, United States
| | - Melinda Liu Perkins
- Department
of Electrical Engineering and Computer Sciences, University of California − Berkeley, Berkeley, California 94704, United States
| | - Justin Hsia
- Department
of Electrical Engineering and Computer Sciences, University of California − Berkeley, Berkeley, California 94704, United States
| | - Murat Arcak
- Department
of Electrical Engineering and Computer Sciences, University of California − Berkeley, Berkeley, California 94704, United States
| | - Adam Paul Arkin
- Department
of Bioengineering, University of California
− Berkeley, Berkeley, California 94704, United States
- Environmental
Genomics and Systems Biology Division, Lawrence
Berkeley National Lab, Berkeley, California 94720, United States
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84
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Santos‐Moreno J, Schaerli Y. Using Synthetic Biology to Engineer Spatial Patterns. ACTA ACUST UNITED AC 2018; 3:e1800280. [DOI: 10.1002/adbi.201800280] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/14/2018] [Indexed: 12/21/2022]
Affiliation(s)
- Javier Santos‐Moreno
- Department of Fundamental MicrobiologyUniversity of LausanneBiophore Building 1015 Lausanne Switzerland
| | - Yolanda Schaerli
- Department of Fundamental MicrobiologyUniversity of LausanneBiophore Building 1015 Lausanne Switzerland
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85
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Sankaran S, Del Campo A. Optoregulated Protein Release from an Engineered Living Material. ACTA ACUST UNITED AC 2018; 3:e1800312. [PMID: 32627372 DOI: 10.1002/adbi.201800312] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 12/04/2018] [Indexed: 12/20/2022]
Abstract
Developing materials to encapsulate and deliver functional proteins inside the body is a challenging yet rewarding task for therapeutic purposes. High production costs, mostly associated with the purification process, short-term stability in vivo, and controlled and prolonged release are major hurdles for the clinical application of protein-based biopharmaceuticals. In an attempt to overcome these hurdles, herein, the possibility of incorporating bacteria as protein factories into a material and externally controlling protein release using optogenetics is demonstrated. By engineering bacteria to express and secrete a red fluorescent protein in response to low doses of blue light irradiation and embedding them in agarose hydrogels, living materials are fabricated capable of releasing proteins into the surrounding medium when exposed to light. These bacterial hydrogels allow spatially confined protein expression and dosed protein release over several weeks, regulated by the area and extent of light exposure. The possibility of incorporating such complex functions in a material using relatively simple material and genetic engineering strategies highlights the immense potential and versatility offered by living materials for protein-based biopharmaceutical delivery.
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Affiliation(s)
| | - Aránzazu Del Campo
- INM - Leibniz Institute for New Materials, Campus D2 2, 66123, Saarbrücken, Germany.,Chemistry Department, Saarland University, 66123, Saarbrücken, Germany
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86
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Wang Y, Liu Q, Weng H, Shi Y, Chen J, Du G, Kang Z. Construction of Synthetic Promoters by Assembling the Sigma Factor Binding -35 and -10 Boxes. Biotechnol J 2018; 14:e1800298. [PMID: 30457214 DOI: 10.1002/biot.201800298] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 10/24/2018] [Indexed: 12/12/2022]
Abstract
Promoter is one of the key elements in regulating gene expression. Many natural or synthetic promoters have been modulated by their cis- or tans-regulatory elements to confer instant gene expression change in responding to designated stimuli. In addition, bacterial cells also engage different sigma factors to control the gene expression network at different growth phases or in response to the changing environment and external stresses. In this study, a set of promoters that assimilate the endogenous regulation of different sigma factors σ70 , σ38 , σ32 , and σ24 are synthesized. Promoters are designed to contain two or more kinds of interlocking sigma factor binding sites. The most competitive sigma factors will be automatically selected by the cell to take over the synthetic promoters during the cell growth course. Some of the synthetic promoters exhibit very strong strengths under different conditions, including stationary phase, low temperature, acidic pH, and high osmotic pressure. Comparing to the T7 promoter, synthetic promoter P21285 achieved higher yields of L-asparaginase and acid urease in Escherichia coli. The research not only expands the synthetic biology toolbox but also provide another strategy to design and construct synthetic promoters in prokaryotes.
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Affiliation(s)
- Yang Wang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Qingtao Liu
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Huanjiao Weng
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Yanan Shi
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Jian Chen
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Guocheng Du
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
| | - Zhen Kang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.,The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, Wuxi, 214122, China
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87
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Wang W, Li Y, Wang Y, Shi C, Li C, Li Q, Linhardt RJ. Bacteriophage T7 transcription system: an enabling tool in synthetic biology. Biotechnol Adv 2018; 36:2129-2137. [DOI: 10.1016/j.biotechadv.2018.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/30/2018] [Accepted: 10/01/2018] [Indexed: 10/28/2022]
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88
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Moser F, Espah Borujeni A, Ghodasara AN, Cameron E, Park Y, Voigt CA. Dynamic control of endogenous metabolism with combinatorial logic circuits. Mol Syst Biol 2018; 14:e8605. [PMID: 30482789 PMCID: PMC6263354 DOI: 10.15252/msb.20188605] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Revised: 10/25/2018] [Accepted: 10/30/2018] [Indexed: 11/09/2022] Open
Abstract
Controlling gene expression during a bioprocess enables real-time metabolic control, coordinated cellular responses, and staging order-of-operations. Achieving this with small molecule inducers is impractical at scale and dynamic circuits are difficult to design. Here, we show that the same set of sensors can be integrated by different combinatorial logic circuits to vary when genes are turned on and off during growth. Three Escherichia coli sensors that respond to the consumption of feedstock (glucose), dissolved oxygen, and by-product accumulation (acetate) are constructed and optimized. By integrating these sensors, logic circuits implement temporal control over an 18-h period. The circuit outputs are used to regulate endogenous enzymes at the transcriptional and post-translational level using CRISPRi and targeted proteolysis, respectively. As a demonstration, two circuits are designed to control acetate production by matching their dynamics to when endogenous genes are expressed (pta or poxB) and respond by turning off the corresponding gene. This work demonstrates how simple circuits can be implemented to enable customizable dynamic gene regulation.
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Affiliation(s)
- Felix Moser
- Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Amin Espah Borujeni
- Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Amar N Ghodasara
- Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ewen Cameron
- Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Yongjin Park
- Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Christopher A Voigt
- Department of Biological Engineering, Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA, USA
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89
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Zhang S, Voigt CA. Engineered dCas9 with reduced toxicity in bacteria: implications for genetic circuit design. Nucleic Acids Res 2018; 46:11115-11125. [PMID: 30289463 PMCID: PMC6237744 DOI: 10.1093/nar/gky884] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/17/2018] [Accepted: 09/19/2018] [Indexed: 12/26/2022] Open
Abstract
Large synthetic genetic circuits require the simultaneous expression of many regulators. Deactivated Cas9 (dCas9) can serve as a repressor by having a small guide RNA (sgRNA) direct it to bind a promoter. The programmability and specificity of RNA:DNA basepairing simplifies the generation of many orthogonal sgRNAs that, in theory, could serve as a large set of regulators in a circuit. However, dCas9 is toxic in many bacteria, thus limiting how high it can be expressed, and low concentrations are quickly sequestered by multiple sgRNAs. Here, we construct a non-toxic version of dCas9 by eliminating PAM (protospacer adjacent motif) binding with a R1335K mutation (dCas9*) and recovering DNA binding by fusing it to the PhlF repressor (dCas9*_PhlF). Both the 30 bp PhlF operator and 20 bp sgRNA binding site are required to repress a promoter. The larger region required for recognition mitigates toxicity in Escherichia coli, allowing up to 9600 ± 800 molecules of dCas9*_PhlF per cell before growth or morphology are impacted, as compared to 530 ± 40 molecules of dCas9. Further, PhlF multimerization leads to an increase in average cooperativity from n = 0.9 (dCas9) to 1.6 (dCas9*_PhlF). A set of 30 orthogonal sgRNA-promoter pairs are characterized as NOT gates; however, the simultaneous use of multiple sgRNAs leads to a monotonic decline in repression and after 15 are co-expressed the dynamic range is <10-fold. This work introduces a non-toxic variant of dCas9, critical for its use in applications in metabolic engineering and synthetic biology, and exposes a limitation in the number of regulators that can be used in one cell when they rely on a shared resource.
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Affiliation(s)
- Shuyi Zhang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Christopher A Voigt
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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90
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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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91
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The Potential for Convergence between Synthetic Biology and Bioelectronics. Cell Syst 2018; 7:231-244. [DOI: 10.1016/j.cels.2018.08.007] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 05/30/2018] [Accepted: 08/13/2018] [Indexed: 01/20/2023]
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92
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Abstract
In nature, a multitude of mechanisms have emerged for regulating biological processes and, specifically, protein activity. Light as a natural regulatory element is of outstanding interest for studying and modulating protein activity because it can be precisely applied with regard to a site of action, instant of time, or intensity. Naturally occurring photoresponsive proteins, predominantly those containing a light-oxygen-voltage (LOV) domain, have been characterized structurally and mechanistically and also conjugated to various proteins of interest. Immediate advantages of these new photoresponsive proteins such as genetic encoding, no requirement of chemical modification, and reversibility are paid for by difficulties in predicting the envisaged activity or type and site of domain fusion. In this article, we summarize recent advances and give a survey on currently available design concepts for engineering photoswitchable proteins.
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Affiliation(s)
- Swantje Seifert
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
| | - Susanne Brakmann
- Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
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93
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Sankaran S, Zhao S, Muth C, Paez J, del Campo A. Toward Light-Regulated Living Biomaterials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2018; 5:1800383. [PMID: 30128245 PMCID: PMC6097140 DOI: 10.1002/advs.201800383] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/09/2018] [Indexed: 05/12/2023]
Abstract
Living materials are an emergent material class, infused with the productive, adaptive, and regenerative properties of living organisms. Property regulation in living materials requires encoding responsive units in the living components to allow external manipulation of their function. Here, an optoregulated Escherichia coli (E. coli)-based living biomaterial that can be externally addressed using light to interact with mammalian cells is demonstrated. This is achieved by using a photoactivatable inducer of gene expression and bacterial surface display technology to present an integrin-specific miniprotein on the outer membrane of an endotoxin-free E. coli strain. Hydrogel surfaces functionalized with the bacteria can expose cell adhesive molecules upon in situ light-activation, and trigger cell adhesion. Surface immobilized bacteria are able to deliver a fluorescent protein to the mammalian cells with which they are interacting, indicating the potential of such a bacterial material to deliver molecules to cells in a targeted manner.
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Affiliation(s)
| | - Shifang Zhao
- INM – Leibniz Institute for New MaterialsCampus D2 266123SaarbrückenGermany
- Chemistry DepartmentSaarland University66123SaarbrückenGermany
| | - Christina Muth
- INM – Leibniz Institute for New MaterialsCampus D2 266123SaarbrückenGermany
| | - Julieta Paez
- INM – Leibniz Institute for New MaterialsCampus D2 266123SaarbrückenGermany
| | - Aránzazu del Campo
- INM – Leibniz Institute for New MaterialsCampus D2 266123SaarbrückenGermany
- Chemistry DepartmentSaarland University66123SaarbrückenGermany
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94
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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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95
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Guyet A, Dade-Robertson M, Wipat A, Casement J, Smith W, Mitrani H, Zhang M. Mild hydrostatic pressure triggers oxidative responses in Escherichia coli. PLoS One 2018; 13:e0200660. [PMID: 30016375 PMCID: PMC6049941 DOI: 10.1371/journal.pone.0200660] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 06/30/2018] [Indexed: 11/24/2022] Open
Abstract
Hydrostatic pressure is an important physical stimulus which can cause various responses in bacterial cells. The survival and cellular processes of Escherichia coli under hydrostatic pressures between 10 MPa and 110 MPa have been studied. However, understanding bacterial responses to moderately elevated pressure of up to 10 MPa is useful for a range of different applications including for example in smart and responsive materials. In this study, the genetic responses of E. coli K-12 MG1655 to 1 MPa pressure was examined using transcriptomic analysis by RNA-Seq. The results show that 101 genes were differentially expressed under 1 MPa pressure in E. coli cells, with 85 of them up-regulated. The analysis suggested that some genes were over expressed to adapt the increase of oxygen levels in our system, and several functional categories are involved including oxidative stress responses, Fe-S cluster assembly and iron acquisition. Two differentially expressed genes azuC and entC were further investigated using RT-qPCR, and GFP reported strains of those two genes were created, AG1319 (PazuCazuC-msfgfp) and AG1321 (PentCentC-msfgfp). A linear response of azuC expression was observed between 0 MPa to 1 MPa by monitoring the fluorescence signal of strain AG1319 (PazuCazuC-msfgfp). This study is the first report to demonstrate the genetic response of bacterial cells under 1 MPa hydrostatic pressure, and provides preliminary data for creating pressure sensing bacterial strains for a wide range of applications.
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Affiliation(s)
- Aurelie Guyet
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Martyn Dade-Robertson
- School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
- School of Architecture Planning and Landscape, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Anil Wipat
- School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - John Casement
- Bioinformatics Support Unit, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Wendy Smith
- School of Computing, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Helen Mitrani
- School of Engineering, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Meng Zhang
- Department of Applied Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
- * E-mail:
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96
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Abstract
Sensory photoreceptors underpin light-dependent adaptations of organismal physiology, development, and behavior in nature. Adapted for optogenetics, sensory photoreceptors become genetically encoded actuators and reporters to enable the noninvasive, spatiotemporally accurate and reversible control by light of cellular processes. Rooted in a mechanistic understanding of natural photoreceptors, artificial photoreceptors with customized light-gated function have been engineered that greatly expand the scope of optogenetics beyond the original application of light-controlled ion flow. As we survey presently, UV/blue-light-sensitive photoreceptors have particularly allowed optogenetics to transcend its initial neuroscience applications by unlocking numerous additional cellular processes and parameters for optogenetic intervention, including gene expression, DNA recombination, subcellular localization, cytoskeleton dynamics, intracellular protein stability, signal transduction cascades, apoptosis, and enzyme activity. The engineering of novel photoreceptors benefits from powerful and reusable design strategies, most importantly light-dependent protein association and (un)folding reactions. Additionally, modified versions of these same sensory photoreceptors serve as fluorescent proteins and generators of singlet oxygen, thereby further enriching the optogenetic toolkit. The available and upcoming UV/blue-light-sensitive actuators and reporters enable the detailed and quantitative interrogation of cellular signal networks and processes in increasingly more precise and illuminating manners.
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Affiliation(s)
- Aba Losi
- Department of Mathematical, Physical and Computer Sciences , University of Parma , Parco Area delle Scienze 7/A-43124 Parma , Italy
| | - Kevin H Gardner
- Structural Biology Initiative, CUNY Advanced Science Research Center , New York , New York 10031 , United States.,Department of Chemistry and Biochemistry, City College of New York , New York , New York 10031 , United States.,Ph.D. Programs in Biochemistry, Chemistry, and Biology , The Graduate Center of the City University of New York , New York , New York 10016 , United States
| | - Andreas Möglich
- Lehrstuhl für Biochemie , Universität Bayreuth , 95447 Bayreuth , Germany.,Research Center for Bio-Macromolecules , Universität Bayreuth , 95447 Bayreuth , Germany.,Bayreuth Center for Biochemistry & Molecular Biology , Universität Bayreuth , 95447 Bayreuth , Germany
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97
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98
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Li M, Zhou M, Tian X, Tan C, McDaniel CT, Hassett DJ, Gu T. Microbial fuel cell (MFC) power performance improvement through enhanced microbial electrogenicity. Biotechnol Adv 2018; 36:1316-1327. [DOI: 10.1016/j.biotechadv.2018.04.010] [Citation(s) in RCA: 126] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 04/28/2018] [Accepted: 04/28/2018] [Indexed: 10/17/2022]
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99
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Karig D, Martini KM, Lu T, DeLateur NA, Goldenfeld N, Weiss R. Stochastic Turing patterns in a synthetic bacterial population. Proc Natl Acad Sci U S A 2018; 115:6572-6577. [PMID: 29891706 PMCID: PMC6042114 DOI: 10.1073/pnas.1720770115] [Citation(s) in RCA: 89] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The origin of biological morphology and form is one of the deepest problems in science, underlying our understanding of development and the functioning of living systems. In 1952, Alan Turing showed that chemical morphogenesis could arise from a linear instability of a spatially uniform state, giving rise to periodic pattern formation in reaction-diffusion systems but only those with a rapidly diffusing inhibitor and a slowly diffusing activator. These conditions are disappointingly hard to achieve in nature, and the role of Turing instabilities in biological pattern formation has been called into question. Recently, the theory was extended to include noisy activator-inhibitor birth and death processes. Surprisingly, this stochastic Turing theory predicts the existence of patterns over a wide range of parameters, in particular with no severe requirement on the ratio of activator-inhibitor diffusion coefficients. To explore whether this mechanism is viable in practice, we have genetically engineered a synthetic bacterial population in which the signaling molecules form a stochastic activator-inhibitor system. The synthetic pattern-forming gene circuit destabilizes an initially homogenous lawn of genetically engineered bacteria, producing disordered patterns with tunable features on a spatial scale much larger than that of a single cell. Spatial correlations of the experimental patterns agree quantitatively with the signature predicted by theory. These results show that Turing-type pattern-forming mechanisms, if driven by stochasticity, can potentially underlie a broad range of biological patterns. These findings provide the groundwork for a unified picture of biological morphogenesis, arising from a combination of stochastic gene expression and dynamical instabilities.
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Affiliation(s)
- David Karig
- Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD 21218
| | - K Michael Martini
- Department of Physics, Center for the Physics of Living Cells and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Ting Lu
- Department of Bioengineering and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801
| | - Nicholas A DeLateur
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Nigel Goldenfeld
- Department of Physics, Center for the Physics of Living Cells and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801;
| | - Ron Weiss
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139
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100
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Near-infrared light-controlled systems for gene transcription regulation, protein targeting and spectral multiplexing. Nat Protoc 2018; 13:1121-1136. [PMID: 29700485 DOI: 10.1038/nprot.2018.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Near-infrared (NIR, 740-780 nm) optogenetic systems are well-suited to spectral multiplexing with blue-light-controlled tools. Here, we present two protocols, one for regulation of gene transcription and another for control of protein localization, that use a NIR-responsive bacterial phytochrome BphP1-QPAS1 optogenetic pair. In the first protocol, cells are transfected with the optogenetic constructs for independently controlling gene transcription by NIR (BphP1-QPAS1) and blue (LightOn) light. The NIR and blue-light-controlled gene transcription systems show minimal spectral crosstalk and induce a 35- to 40-fold increase in reporter gene expression. In the second protocol, the BphP1-QPAS1 pair is combined with a light-oxygen-voltage-sensing (LOV) domain-based construct into a single optogenetic tool, termed iRIS. This dual-light-controllable protein localization tool allows tridirectional protein translocation among the cytoplasm, nucleus and plasma membrane. Both procedures can be performed within 3-5 d. Use of NIR light-controlled optogenetic systems should advance basic and biomedical research.
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