1
|
Elahi Y, Baker MAB. Light Control in Microbial Systems. Int J Mol Sci 2024; 25:4001. [PMID: 38612810 PMCID: PMC11011852 DOI: 10.3390/ijms25074001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
Light is a key environmental component influencing many biological processes, particularly in prokaryotes such as archaea and bacteria. Light control techniques have revolutionized precise manipulation at molecular and cellular levels in recent years. Bacteria, with adaptability and genetic tractability, are promising candidates for light control studies. This review investigates the mechanisms underlying light activation in bacteria and discusses recent advancements focusing on light control methods and techniques for controlling bacteria. We delve into the mechanisms by which bacteria sense and transduce light signals, including engineered photoreceptors and light-sensitive actuators, and various strategies employed to modulate gene expression, protein function, and bacterial motility. Furthermore, we highlight recent developments in light-integrated methods of controlling microbial responses, such as upconversion nanoparticles and optical tweezers, which can enhance the spatial and temporal control of bacteria and open new horizons for biomedical applications.
Collapse
|
2
|
Wang XG, Zou ZP, Du Y, Ye BC, Zhou Y. Construction of an Engineered Escherichia coli with Efficient Chemotactic and Metabolizing Ability toward Tetrathionate. ACS Synth Biol 2023; 12:3414-3423. [PMID: 37939253 DOI: 10.1021/acssynbio.3c00445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2023]
Abstract
The emergence of genetically engineered bacteria has provided a new means for the diagnosis and treatment of diseases. However, in vivo applications of these engineered bacteria are hindered by their inefficient accumulation in areas of inflammation. In this study, we constructed an engineered Escherichia coli (E. coli) for directional migration toward tetrathionate (a biomarker of gut inflammation), which is regulated by the TtrSR two-component system (TCS) from Shewanella baltica OS195 (S. baltica). Specifically, we removed endogenous cheZ to control the motility of E. coli. Moreover, we introduced the reductase gene cluster (ttrBCA) from Salmonella enterica serotype typhimurium (S. typhimurium), a major pathogen causing gut inflammation, into E. coli to metabolize tetrathionate. The resulting strain was tested for its motility along the gradients of tetrathionate; the engineered strain exhibits tropism to tetrathionate compared with the original strain. Furthermore, the engineered E. coli could only restore its smooth swimming ability when tetrathionate existed. With these modifications enabling tetrathionate-mediated chemotactic and metabolizing activity, this strategy with therapeutic elements will provide a great potential opportunity for target treatment of various diseases by swapping the corresponding genetic circuits.
Collapse
Affiliation(s)
- Xin-Ge Wang
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong RD 130, Shanghai 200237, China
| | - Zhen-Ping Zou
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong RD 130, Shanghai 200237, China
| | - Yue Du
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong RD 130, Shanghai 200237, China
| | - Bang-Ce Ye
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong RD 130, Shanghai 200237, China
| | - Ying Zhou
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Meilong RD 130, Shanghai 200237, China
| |
Collapse
|
3
|
Schmitz FRW, Valério A, de Oliveira D, Hotza D. An overview and future prospects on aptamers for food safety. Appl Microbiol Biotechnol 2020; 104:6929-6939. [PMID: 32588103 PMCID: PMC7315907 DOI: 10.1007/s00253-020-10747-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 06/10/2020] [Accepted: 06/16/2020] [Indexed: 02/07/2023]
Abstract
Introduction Many bacteria are responsible for infections in humans and plants, being found in vegetables, water, and medical devices. Most bacterial detection methods are time-consuming and take days to give the result. Aptamers are a promising alternative for a quick and reliable measurement technique to detect bacteria present in food products. Selected aptamers are DNA or RNA oligonucleotides that can bind with bacteria or other molecules with affinity and specificity for the target cells by the SELEX or cell-SELEX technique. This method is based on some rounds to remove the non-ligand oligonucleotides, leaving the aptamers specific to bind to the selected bacteria. Compared with conventional methodologies, the detection approach using aptamers is a rapid, low-cost form of analysis. Objective This review summarizes obtention methods and applications of aptamers in the food industry and biotechnology. Besides, different techniques with aptamers are presented, which enable more effective target detection. Conclusion Applications of aptamers as biosensors, or the association of aptamers with nanomaterials, may be employed in analyses by colorimetric, fluorescence, or electrical devices. Additionally, more efficient ways of sample preparation are presented, which can support food safety to provide human health, with a low-cost method for contaminant detection.Key points • Aptamers are promising for detecting contaminants outbreaks. • Studies are needed to identify aptamers for different targets. |
Collapse
Affiliation(s)
- Fernanda Raquel Wust Schmitz
- Department of Chemical Engineering and Food Engineering (EQA), Federal University of Santa Catarina (UFSC), Florianópolis, SC, 88040-900, Brazil
| | - Alexsandra Valério
- Department of Chemical Engineering and Food Engineering (EQA), Federal University of Santa Catarina (UFSC), Florianópolis, SC, 88040-900, Brazil
| | - Débora de Oliveira
- Department of Chemical Engineering and Food Engineering (EQA), Federal University of Santa Catarina (UFSC), Florianópolis, SC, 88040-900, Brazil.
| | - Dachamir Hotza
- Department of Chemical Engineering and Food Engineering (EQA), Federal University of Santa Catarina (UFSC), Florianópolis, SC, 88040-900, Brazil
| |
Collapse
|
4
|
Zhang J, Luo Y, Poh CL. Blue Light-Directed Cell Migration, Aggregation, and Patterning. J Mol Biol 2020; 432:3137-3148. [PMID: 32247761 DOI: 10.1016/j.jmb.2020.03.029] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/19/2020] [Accepted: 03/26/2020] [Indexed: 12/17/2022]
Abstract
Bacterial motility is related to many cellular activities, such as cell migration, aggregation, and biofilm formations. The ability to control motility and direct the bacteria to certain location could be used to guide the bacteria in applications such as seeking for and killing pathogen, forming various population-level patterns, and delivering of drugs and vaccines. Currently, bacteria motility is mainly controlled by chemotaxis (prescribed chemical stimuli), which needs physical contact with the chemical inducer. This lacks the flexibility for pattern formation as it has limited spatial control. To overcome the limitations, we developed blue light-regulated synthetic genetic circuit to control bacterial directional motility, by taking the advantage that light stimulus can be delivered to cells in different patterns with precise spatial control. The circuit developed enables programmed Escherichia coli cells to increase directional motility and move away from the blue light, i.e., that negative phototaxis is utilized. This further allows the control of the cells to form aggregation with different patterns. Further, we showed that the circuit can be used to separate two different strains. The demonstrated ability of blue light-controllable gene circuits to regulate a CheZ expression could give researchers more means to control bacterial motility and pattern formation.
Collapse
Affiliation(s)
- Jingyun Zhang
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore
| | - Yuhuan Luo
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore
| | - Chueh Loo Poh
- Department of Biomedical Engineering, Faculty of Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore; NUS Synthetic Biology for Clinical and Technological Innovation (SynCTI), Life Sciences Institute, National University of Singapore, 28 Medical Drive, Singapore 117456, Singapore.
| |
Collapse
|
5
|
Zhang Y, Lai BS, Juhas M. Recent Advances in Aptamer Discovery and Applications. Molecules 2019; 24:molecules24050941. [PMID: 30866536 PMCID: PMC6429292 DOI: 10.3390/molecules24050941] [Citation(s) in RCA: 335] [Impact Index Per Article: 67.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 03/03/2019] [Accepted: 03/04/2019] [Indexed: 12/22/2022] Open
Abstract
Aptamers are short, single-stranded DNA, RNA, or synthetic XNA molecules that can be developed with high affinity and specificity to interact with any desired targets. They have been widely used in facilitating discoveries in basic research, ensuring food safety and monitoring the environment. Furthermore, aptamers play promising roles as clinical diagnostics and therapeutic agents. This review provides update on the recent advances in this rapidly progressing field of research with particular emphasis on generation of aptamers and their applications in biosensing, biotechnology and medicine. The limitations and future directions of aptamers in target specific delivery and real-time detection are also discussed.
Collapse
Affiliation(s)
- Yang Zhang
- College of Science, Harbin Institute of Technology, Shenzhen 518055, China.
| | - Bo Shiun Lai
- School of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA.
| | - Mario Juhas
- Institute of Medical Microbiology, University of Zurich, Gloriastrasse 28/30, CH-8006 Zurich, Switzerland.
| |
Collapse
|
6
|
Neuner E, Frener M, Lusser A, Micura R. Superior cellular activities of azido- over amino-functionalized ligands for engineered preQ 1 riboswitches in E.coli. RNA Biol 2018; 15:1376-1383. [PMID: 30332908 PMCID: PMC6284575 DOI: 10.1080/15476286.2018.1534526] [Citation(s) in RCA: 6] [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: 09/29/2018] [Accepted: 10/05/2018] [Indexed: 01/29/2023] Open
Abstract
For this study, we utilized class-I and class-II preQ1-sensing riboswitches as model systems to decipher the structure-activity relationship of rationally designed ligand derivatives in vitro and in vivo. We found that synthetic preQ1 ligands with amino-modified side chains that protrude from the ligand-encapsulating binding pocket, and thereby potentially interact with the phosphate backbone in their protonated form, retain or even increase binding affinity for the riboswitches in vitro. They, however, led to significantly lower riboswitch activities in a reporter system in vivo in E. coli. Importantly, when we substituted the amino- by azido-modified side chains, the cellular activities of the ligands were restored for the class-I conditional gene expression system and even improved for the class-II counterpart. Kinetic analysis of ligand binding in vitro revealed enhanced on-rates for amino-modified derivatives while they were attenuated for azido-modified variants. This shows that neither high affinities nor fast on-rates are necessarily translated into efficient cellular activities. Taken together, our comprehensive study interconnects in vitro kinetics and in vitro thermodynamics of RNA-ligand binding with the ligands' in vivo performance and thereby encourages azido- rather than amino-functionalized design for enhanced cellular activity.
Collapse
Affiliation(s)
- Eva Neuner
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University, Innsbruck, Austria
| | - Marina Frener
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University, Innsbruck, Austria
| | - Alexandra Lusser
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Ronald Micura
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck CMBI, Leopold-Franzens University, Innsbruck, Austria
| |
Collapse
|
7
|
McKay R, Ghodasra M, Schardt J, Quan D, Pottash AE, Shang W, Jay SM, Payne GF, Chang MW, March JC, Bentley WE. A platform of genetically engineered bacteria as vehicles for localized delivery of therapeutics: Toward applications for Crohn's disease. Bioeng Transl Med 2018; 3:209-221. [PMID: 30377661 PMCID: PMC6195910 DOI: 10.1002/btm2.10113] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 08/22/2018] [Accepted: 08/22/2018] [Indexed: 12/14/2022] Open
Abstract
For therapies targeting diseases of the gastrointestinal tract, we and others envision probiotic bacteria that synthesize and excrete biotherapeutics at disease sites. Toward this goal, we have engineered commensal E. coli that selectively synthesize and secrete a model biotherapeutic in the presence of nitric oxide (NO), an intestinal biomarker for Crohn's disease (CD). This is accomplished by co‐expressing the pore forming protein TolAIII with the biologic, granulocyte macrophage‐colony stimulating factor (GM‐CSF). We have additionally engineered these bacteria to accumulate at sites of elevated NO by engineering their motility circuits and controlling pseudotaxis. Importantly, because we have focused on in vitro test beds, motility and biotherapeutics production are spatiotemporally characterized. Together, the targeted recognition, synthesis, and biomolecule delivery comprises a “smart” probiotics platform that may have utility in the treatment of CD. Further, this platform could be modified to accommodate other pursuits by swapping the promoter and therapeutic gene to reflect other disease biomarkers and treatments, respectively.
Collapse
Affiliation(s)
- Ryan McKay
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Institute for Bioscience and Biotechnology Research University of Maryland College Park MD
| | - Monil Ghodasra
- Fischell Dept. of Bioengineering University of Maryland College Park MD
| | - John Schardt
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute National Institutes of Health Bethesda MD
| | - David Quan
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Institute for Bioscience and Biotechnology Research University of Maryland College Park MD
| | - Alex Eli Pottash
- Fischell Dept. of Bioengineering University of Maryland College Park MD
| | - Wu Shang
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Institute for Bioscience and Biotechnology Research University of Maryland College Park MD
| | - Steven M Jay
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Women's Malignancies Branch, Center for Cancer Research, National Cancer Institute National Institutes of Health Bethesda MD.,Marlene and Stewart Greenebaum Comprehensive Cancer Center University of Maryland School of Medicine Baltimore MD.,Program in Molecular and Cellular Biology University of Maryland College Park MD
| | - Gregory F Payne
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Institute for Bioscience and Biotechnology Research University of Maryland College Park MD
| | - Matthew Wook Chang
- Dept. of Biochemistry, Yong Loo Lin School of Medicine National University of Singapore Singapore.,NUS Synthetic Biology for Clinical and Technological Innovation, Life Sciences Institute National University of Singapore Singapore
| | - John C March
- Dept. of Biological and Environmental Engineering Cornell University Ithaca NY
| | - William E Bentley
- Fischell Dept. of Bioengineering University of Maryland College Park MD.,Institute for Bioscience and Biotechnology Research University of Maryland College Park MD
| |
Collapse
|
8
|
Patel S, Panchasara H, Braddick D, Gohil N, Singh V. Synthetic small RNAs: Current status, challenges, and opportunities. J Cell Biochem 2018; 119:9619-9639. [DOI: 10.1002/jcb.27252] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/20/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Shreya Patel
- Department of Microbiology, Synthetic Biology Laboratory School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area Gandhinagar India
| | - Happy Panchasara
- Department of Microbiology, Synthetic Biology Laboratory School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area Gandhinagar India
| | | | - Nisarg Gohil
- Department of Microbiology, Synthetic Biology Laboratory School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area Gandhinagar India
| | - Vijai Singh
- Department of Microbiology, Synthetic Biology Laboratory School of Biological Sciences and Biotechnology, Institute of Advanced Research, Koba Institutional Area Gandhinagar India
| |
Collapse
|
9
|
Cai Y, Xia M, Dong H, Qian Y, Zhang T, Zhu B, Wu J, Zhang D. Engineering a vitamin B 12 high-throughput screening system by riboswitch sensor in Sinorhizobium meliloti. BMC Biotechnol 2018; 18:27. [PMID: 29751749 PMCID: PMC5948670 DOI: 10.1186/s12896-018-0441-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 04/30/2018] [Indexed: 12/23/2022] Open
Abstract
Background As a very important coenzyme in the cell metabolism, Vitamin B12 (cobalamin, VB12) has been widely used in food and medicine fields. The complete biosynthesis of VB12 requires approximately 30 genes, but overexpression of these genes did not result in expected increase of VB12 production. High-yield VB12-producing strains are usually obtained by mutagenesis treatments, thus developing an efficient screening approach is urgently needed. Result By the help of engineered strains with varied capacities of VB12 production, a riboswitch library was constructed and screened, and the btuB element from Salmonella typhimurium was identified as the best regulatory device. A flow cytometry high-throughput screening system was developed based on the btuB riboswitch with high efficiency to identify positive mutants. Mutation of Sinorhizobium meliloti (S. meliloti) was optimized using the novel mutation technique of atmospheric and room temperature plasma (ARTP). Finally, the mutant S. meliloti MC5–2 was obtained and considered as a candidate for industrial applications. After 7 d’s cultivation on a rotary shaker at 30 °C, the VB12 titer of S. meliloti MC5–2 reached 156 ± 4.2 mg/L, which was 21.9% higher than that of the wild type strain S. meliloti 320 (128 ± 3.2 mg/L). The genome of S. meliloti MC5–2 was sequenced, and gene mutations were identified and analyzed. Conclusion To our knowledge, it is the first time that a riboswitch element was used in S. meliloti. The flow cytometry high-throughput screening system was successfully developed and a high-yield VB12 producing strain was obtained. The identified and analyzed gene mutations gave useful information for developing high-yield strains by metabolic engineering. Overall, this work provides a useful high-throughput screening method for developing high VB12-yield strains. Electronic supplementary material The online version of this article (10.1186/s12896-018-0441-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Yingying Cai
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,College of Biotechnology, Tianjin University of Science & Technology, No. 29, thirteenth Avenue Binhai District, Tianjin, 300457, China
| | - Miaomiao Xia
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Huina Dong
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Yuan Qian
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China.,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China
| | - Tongcun Zhang
- College of Biotechnology, Tianjin University of Science & Technology, No. 29, thirteenth Avenue Binhai District, Tianjin, 300457, China
| | - Beiwei Zhu
- School of Food Science and Technology, Dalian Polytechnic University, National Engineering Research Center of Seafood, Dalian, 116034, People's Republic of China
| | - Jinchuan Wu
- Industrial Biotechnology Division, Institute of Chemical and Engineering Sciences, 1 Pesek Road, Jurong Island, 627833, Singapore
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China. .,Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, 32 West 7th Avenue, Tianjin Airport Economic Area, Tianjin, 300308, China. .,School of Food Science and Technology, Dalian Polytechnic University, National Engineering Research Center of Seafood, Dalian, 116034, People's Republic of China.
| |
Collapse
|
10
|
Yokobayashi Y. Small Molecule-Responsive RNA Switches (Bacteria): Important Element of Programming Gene Expression in Response to Environmental Signals in Bacteria. Synth Biol (Oxf) 2018. [DOI: 10.1002/9783527688104.ch9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Yohei Yokobayashi
- Okinawa Institute of Science and Technology Graduate University; Nucleic Acid Chemistry and Engineering Unit Onna-son; Okinawa 9040415 Japan
| |
Collapse
|
11
|
Nie Y, Teng Y, Li P, Liu W, Shi Q, Zhang Y. Label-free aptamer-based sensor for specific detection of malathion residues by surface-enhanced Raman scattering. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 191:271-276. [PMID: 29045930 DOI: 10.1016/j.saa.2017.10.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 09/29/2017] [Accepted: 10/09/2017] [Indexed: 06/07/2023]
Abstract
A novel label-free aptamer surface-enhanced Raman scattering (SERS) sensor for trace malathion residue detection was proposed. In this process, the binding of malathion molecule with aptamer is identified directly. The silver nanoparticles modified with positively charged spermine served as enhancing and capture reagents for the negatively charged aptamer. Then, the silver nanoparticles modified by aptamer were used to specifically capture the malathion. The SERS background spectra of spermine, aptamer, and malathion were recorded and distinguished with the spectrum of malathion-aptamer. To enhance the characteristic peak signal of malathion captured by the aptamer, the aggregate reagents (NaCl, KCl, MgCl2) were compared and selected. The selectivity of this method was verified in the mixed-pesticide standard solution, which included malathion, phosmet, chlorpyrifos-methyl, and fethion. Results show that malathion can be specifically identified when the mixed-pesticide interferences existed. The standard curve was established, presenting a good linear range of 5×10-7 to 1×10-5mol·L-1. The spiked experiments for tap water show good recoveries from 87.4% to 110.5% with a relative standard deviation of less than 4.22%. Therefore, the proposed label-free aptamer SERS sensor is convenient, specifically detects trace malathion residues, and can be applied for qualitative and quantitative analysis of other pesticides.
Collapse
Affiliation(s)
- Yonghui Nie
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yuanjie Teng
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
| | - Pan Li
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Wenhan Liu
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China.
| | - Qianwei Shi
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| | - Yuchao Zhang
- State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310032, China
| |
Collapse
|
12
|
McKay R, Hauk P, Wu HC, Pottash AE, Shang W, Terrell J, Payne GF, Bentley WE. Controlling localization of Escherichia coli populations using a two-part synthetic motility circuit: An accelerator and brake. Biotechnol Bioeng 2017; 114:2883-2895. [PMID: 28755474 DOI: 10.1002/bit.26391] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/21/2017] [Accepted: 07/23/2017] [Indexed: 12/30/2022]
Abstract
Probiotics, whether taken as capsules or consumed in foods, have been regarded as safe for human use by regulatory agencies. Being living cells, they serve as "tunable" factories for the synthesis of a vast array of beneficial molecules. The idea of reprogramming probiotics to act as controllable factories, producing potential therapeutic molecules under user-specified conditions, represents a new and powerful concept in drug synthesis and delivery. Probiotics that serve as drug delivery vehicles pose several challenges, one being targeting (as seen with nanoparticle approaches). Here, we employ synthetic biology to control swimming directionality in a process referred to as "pseudotaxis." Escherichia coli, absent the motility regulator cheZ, swim sporadically, missing the traditional "run" in the run:tumble swimming paradigm. Upon introduction of cheZ in trans and its signal-generated upregulation, engineered bacteria can be "programmed" to swim toward the source of the chemical cue. Here, engineered cells that encounter sufficient levels of the small signal molecule pyocyanin, produce an engineered CheZ and swim with programmed directionality. By incorporating a degradation tag at the C-terminus of CheZ, the cells stop running when they exit spaces containing pyocyanin. That is, the engineered CheZ modified with a C-terminal extension derived from the putative DNA-binding transcriptional regulator YbaQ (RREERAAKKVA) is consumed by the ClpXP protease machine at a rate sufficient to "brake" the cells when pyocyanin levels are too low. Through this process, we demonstrate that over time, these engineered E. coli accumulate in pyocyanin-rich locales. We suggest that such approaches may find utility in engineering probiotics so that their beneficial functions can be focused in areas of principal benefit.
Collapse
Affiliation(s)
- Ryan McKay
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland
| | - Pricila Hauk
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland
| | - Hsuan-Chen Wu
- Department of Biochemical Science and Technology, National Taiwan University, Taipei City, Taiwan
| | - Alex Eli Pottash
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland
| | - Wu Shang
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland
| | | | - Gregory F Payne
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland
| | - William E Bentley
- Fischell Department of Bioengineering, University of Maryland, College Park, Maryland.,Institute for Bioscience and Biotechnology Research, University of Maryland, College Park, Maryland
| |
Collapse
|
13
|
Transcriptional control of motility enables directional movement of Escherichia coli in a signal gradient. Sci Rep 2017; 7:8959. [PMID: 28827562 PMCID: PMC5566481 DOI: 10.1038/s41598-017-08870-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/18/2017] [Indexed: 11/08/2022] Open
Abstract
Manipulation of cellular motility using a target signal can facilitate the development of biosensors or microbe-powered biorobots. Here, we engineered signal-dependent motility in Escherichia coli via the transcriptional control of a key motility gene. Without manipulating chemotaxis, signal-dependent switching of motility, either on or off, led to population-level directional movement of cells up or down a signal gradient. We developed a mathematical model that captures the behaviour of the cells, enables identification of key parameters controlling system behaviour, and facilitates predictive-design of motility-based pattern formation. We demonstrated that motility of the receiver strains could be controlled by a sender strain generating a signal gradient. The modular quorum sensing-dependent architecture for interfacing different senders with receivers enabled a broad range of systems-level behaviours. The directional control of motility, especially combined with the potential to incorporate tuneable sensors and more complex sensing-logic, may lead to tools for novel biosensing and targeted-delivery applications.
Collapse
|
14
|
Enabling tools for high-throughput detection of metabolites: Metabolic engineering and directed evolution applications. Biotechnol Adv 2017; 35:950-970. [PMID: 28723577 DOI: 10.1016/j.biotechadv.2017.07.005] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Revised: 06/07/2017] [Accepted: 07/11/2017] [Indexed: 12/21/2022]
Abstract
Within the Design-Build-Test Cycle for strain engineering, rapid product detection and selection strategies remain challenging and limit overall throughput. Here we summarize a wide variety of modalities that transduce chemical concentrations into easily measured absorbance, luminescence, and fluorescence signals. Specifically, we cover protein-based biosensors (including transcription factors), nucleic acid-based biosensors, coupled enzyme reactions, bioorthogonal chemistry, and fluorescent and chromogenic dyes and substrates as modalities for detection. We focus on the use of these methods for strain engineering and enzyme discovery and conclude with remarks on the current and future state of biosensor development for application in the metabolic engineering field.
Collapse
|
15
|
Liu Y, Zhuang Y, Ding D, Xu Y, Sun J, Zhang D. Biosensor-Based Evolution and Elucidation of a Biosynthetic Pathway in Escherichia coli. ACS Synth Biol 2017; 6:837-848. [PMID: 28121425 DOI: 10.1021/acssynbio.6b00328] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The successful evolution of metabolite-producing microbes requires a high-throughput screening method to obtain the desired properties within a short time. In this study, we developed a transcription-factor-driven device that combines a metabolite-responsive element and a selection module. This device was able to specifically sense intracellular l-phenylalanine (l-Phe) and convert this signal into an observable phenotype. Applying this device, we successfully improved l-Phe production by screening hyperproducing phenotypes from a ribonucleotide binding site library and a random mutagenesis library. In addition, several site mutations introduced by random mutagenesis were identified and elucidated to facilitate the improvement of l-Phe production. Our results present a paradigm for screening of compounds that are not easily observable to raise the yield of targeted compounds from a large candidate library. This approach may guide further applications in rewiring metabolic circuits and facilitate the directed evolution of recombinant strains.
Collapse
Affiliation(s)
- Yongfei Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key
Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yinyin Zhuang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Dongqin Ding
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key
Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yiran Xu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key
Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- Key
Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| |
Collapse
|
16
|
Singh RP, Manchanda G, Li ZF, Rai AR. Insight of Proteomics and Genomics in Environmental Bioremediation. ACTA ACUST UNITED AC 2017. [DOI: 10.4018/978-1-5225-2325-3.ch003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Bioremediation of hazardous substances from environment is a major human and environmental health concern but can be managed by the microorganism due to their variety of properties that can effectively change the complexity. Microorganisms convey endogenous genetic, biochemical and physiological assets that make them superlative proxies for pollutant remediation in habitat. But, the crucial step is to degrade the complex ring structured pollutants. Interestingly, the integration of genomics and proteomics technologies that allow us to use or alter the genes and proteins of interest in a given microorganism towards a cell-free bioremediation approach. Resultantly, efforts have been finished by developing the genetically modified (Gm) microbes for the remediation of ecological contaminants. Gm microorganisms mediated bioremediation can affect the solubility, bioavailability and mobility of complex hazardous.
Collapse
|
17
|
Del Vecchio D, Dy AJ, Qian Y. Control theory meets synthetic biology. J R Soc Interface 2016; 13:rsif.2016.0380. [PMID: 27440256 DOI: 10.1098/rsif.2016.0380] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 06/20/2016] [Indexed: 12/15/2022] Open
Abstract
The past several years have witnessed an increased presence of control theoretic concepts in synthetic biology. This review presents an organized summary of how these control design concepts have been applied to tackle a variety of problems faced when building synthetic biomolecular circuits in living cells. In particular, we describe success stories that demonstrate how simple or more elaborate control design methods can be used to make the behaviour of synthetic genetic circuits within a single cell or across a cell population more reliable, predictable and robust to perturbations. The description especially highlights technical challenges that uniquely arise from the need to implement control designs within a new hardware setting, along with implemented or proposed solutions. Some engineering solutions employing complex feedback control schemes are also described, which, however, still require a deeper theoretical analysis of stability, performance and robustness properties. Overall, this paper should help synthetic biologists become familiar with feedback control concepts as they can be used in their application area. At the same time, it should provide some domain knowledge to control theorists who wish to enter the rising and exciting field of synthetic biology.
Collapse
Affiliation(s)
- Domitilla Del Vecchio
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Synthetic Biology Center, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Aaron J Dy
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Yili Qian
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| |
Collapse
|
18
|
Delépine B, Libis V, Carbonell P, Faulon JL. SensiPath: computer-aided design of sensing-enabling metabolic pathways. Nucleic Acids Res 2016; 44:W226-31. [PMID: 27106061 PMCID: PMC5741204 DOI: 10.1093/nar/gkw305] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 04/04/2016] [Accepted: 04/12/2016] [Indexed: 12/17/2022] Open
Abstract
Genetically-encoded biosensors offer a wide range of opportunities to develop advanced synthetic biology applications. Circuits with the ability of detecting and quantifying intracellular amounts of a compound of interest are central to whole-cell biosensors design for medical and environmental applications, and they also constitute essential parts for the selection and regulation of high-producer strains in metabolic engineering. However, the number of compounds that can be detected through natural mechanisms, like allosteric transcription factors, is limited; expanding the set of detectable compounds is therefore highly desirable. Here, we present the SensiPath web server, accessible at http://sensipath.micalis.fr SensiPath implements a strategy to enlarge the set of detectable compounds by screening for multi-step enzymatic transformations converting non-detectable compounds into detectable ones. The SensiPath approach is based on the encoding of reactions through signature descriptors to explore sensing-enabling metabolic pathways, which are putative biochemical transformations of the target compound leading to known effectors of transcription factors. In that way, SensiPath enlarges the design space by broadening the potential use of biosensors in synthetic biology applications.
Collapse
Affiliation(s)
- Baudoin Delépine
- iSSB, Genopole, CNRS, UEVE, Université Paris Saclay, 91000 Évry, France Micalis Institute, INRA, AgroParisTech, Université Paris Saclay, 78350 Jouy-en-Josas, France
| | - Vincent Libis
- iSSB, Genopole, CNRS, UEVE, Université Paris Saclay, 91000 Évry, France Micalis Institute, INRA, AgroParisTech, Université Paris Saclay, 78350 Jouy-en-Josas, France
| | - Pablo Carbonell
- SYNBIOCHEM Centre, Manchester Institute of Biotechnology, University of Manchester, M1 7DN Manchester, UK
| | - Jean-Loup Faulon
- iSSB, Genopole, CNRS, UEVE, Université Paris Saclay, 91000 Évry, France Micalis Institute, INRA, AgroParisTech, Université Paris Saclay, 78350 Jouy-en-Josas, France SYNBIOCHEM Centre, Manchester Institute of Biotechnology, University of Manchester, M1 7DN Manchester, UK
| |
Collapse
|
19
|
Tien SM, Hsu CY, Chen BS. Engineering Bacteria to Search for Specific Concentrations of Molecules by a Systematic Synthetic Biology Design Method. PLoS One 2016; 11:e0152146. [PMID: 27096615 PMCID: PMC4838244 DOI: 10.1371/journal.pone.0152146] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/09/2016] [Indexed: 11/18/2022] Open
Abstract
Bacteria navigate environments full of various chemicals to seek favorable places for survival by controlling the flagella’s rotation using a complicated signal transduction pathway. By influencing the pathway, bacteria can be engineered to search for specific molecules, which has great potential for application to biomedicine and bioremediation. In this study, genetic circuits were constructed to make bacteria search for a specific molecule at particular concentrations in their environment through a synthetic biology method. In addition, by replacing the “brake component” in the synthetic circuit with some specific sensitivities, the bacteria can be engineered to locate areas containing specific concentrations of the molecule. Measured by the swarm assay qualitatively and microfluidic techniques quantitatively, the characteristics of each “brake component” were identified and represented by a mathematical model. Furthermore, we established another mathematical model to anticipate the characteristics of the “brake component”. Based on this model, an abundant component library can be established to provide adequate component selection for different searching conditions without identifying all components individually. Finally, a systematic design procedure was proposed. Following this systematic procedure, one can design a genetic circuit for bacteria to rapidly search for and locate different concentrations of particular molecules by selecting the most adequate “brake component” in the library. Moreover, following simple procedures, one can also establish an exclusive component library suitable for other cultivated environments, promoter systems, or bacterial strains.
Collapse
Affiliation(s)
- Shin-Ming Tien
- Lab of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - Chih-Yuan Hsu
- Lab of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - Bor-Sen Chen
- Lab of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
- * E-mail:
| |
Collapse
|
20
|
Mukherjee K, Bhattacharyya S, Peralta-Yahya P. GPCR-Based Chemical Biosensors for Medium-Chain Fatty Acids. ACS Synth Biol 2015; 4:1261-9. [PMID: 25992593 DOI: 10.1021/sb500365m] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A key limitation to engineering microbes for chemical production is a reliance on low-throughput chromatography-based screens for chemical detection. While colorimetric chemicals are amenable to high-throughput screens, many value-added chemicals are not colorimetric and require sensors for high-throughput screening. Here, we use G-protein coupled receptors (GPCRs) known to bind medium-chain fatty acids in mammalian cells to rapidly construct chemical sensors in yeast. Medium-chain fatty acids are immediate precursors to the advanced biofuel fatty acid methyl esters, which can serve as a "drop-in" replacement for D2 diesel. One of the sensors detects even-chain C8-C12 fatty acids with a 13- to 17-fold increase in signal after activation, with linear ranges up to 250 μM. Introduction of a synthetic response unit alters both dynamic and linear range, improving the sensor response to decanoic acid to a 30-fold increase in signal after activation, with a linear range up to 500 μM. To our knowledge, this is the first report of a whole-cell medium-chain fatty acid biosensor, which we envision could be applied to the evolutionary engineering of fatty acid-producing microbes. Given the affinity of GPCRs for a wide range of chemicals, it should be possible to rapidly assemble new biosensors by simply swapping the GPCR sensing unit. These sensors should be amenable to a variety of applications that require different dynamic and linear ranges, by introducing different response units.
Collapse
Affiliation(s)
- Kuntal Mukherjee
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Souryadeep Bhattacharyya
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Pamela Peralta-Yahya
- School
of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School
of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| |
Collapse
|
21
|
Zhou W, Huang PJJ, Ding J, Liu J. Aptamer-based biosensors for biomedical diagnostics. Analyst 2015; 139:2627-40. [PMID: 24733714 DOI: 10.1039/c4an00132j] [Citation(s) in RCA: 333] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aptamers are single-stranded nucleic acids that selectively bind to target molecules. Most aptamers are obtained through a combinatorial biology technique called SELEX. Since aptamers can be isolated to bind to almost any molecule of choice, can be readily modified at arbitrary positions and they possess predictable secondary structures, this platform technology shows great promise in biosensor development. Over the past two decades, more than one thousand papers have been published on aptamer-based biosensors. Given this progress, the application of aptamer technology in biomedical diagnosis is still in a quite preliminary stage. Most previous work involves only a few model aptamers to demonstrate the sensing concept with limited biomedical impact. This Critical Review aims to summarize progress that might enable practical applications of aptamers for biological samples. First, general sensing strategies based on the unique properties of aptamers are summarized. Each strategy can be coupled to various signaling methods. Among these, a few detection methods including fluorescence lifetime, flow cytometry, upconverting nanoparticles, nanoflare technology, magnetic resonance imaging, electronic aptamer-based sensors, and lateral flow devices have been discussed in more detail since they are more likely to work in a complex sample matrix. The current limitations of this field include the lack of high quality aptamers for clinically important targets. In addition, the aptamer technology has to be extensively tested in a clinical sample matrix to establish reliability and accuracy. Future directions are also speculated to overcome these challenges.
Collapse
Affiliation(s)
- Wenhu Zhou
- Department of Pharmaceutics, School of Pharmaceutical Sciences, Central South University, Tongzipo Road #172, Changsha 410013, Hunan, PR China.
| | | | | | | |
Collapse
|
22
|
Nguyen VT, Kwon YS, Kim JH, Gu MB. Multiple GO-SELEX for efficient screening of flexible aptamers. Chem Commun (Camb) 2015; 50:10513-6. [PMID: 25072407 DOI: 10.1039/c4cc03953j] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We describe a simple, high-speed, high-throughput aptamer screening for a group of small molecules using graphene oxide (simple Multi-GO-SELEX) without immobilizing targets. The affinities of ten different ssDNA aptamers successfully obtained for three pesticides were in the range of 10-100 nM. Besides a specific aptamer for each target, we found a couple of flexible multi-target aptamers, which can bind with 2 or 3 different molecules. These flexible aptamers developed for binding with a mixture of targets are not only significant for the rapid screening of a group of small molecules but also offer great promise for aptamer-based biosensor applications.
Collapse
Affiliation(s)
- Van-Thuan Nguyen
- School of Life Sciences and Biotechnology, Korea University, Anam-dong, Seongbuk-Gu, Seoul 136-713, Republic of Korea.
| | | | | | | |
Collapse
|
23
|
Chaudhary AK, Na D, Lee EY. Rapid and high-throughput construction of microbial cell-factories with regulatory noncoding RNAs. Biotechnol Adv 2015; 33:914-30. [PMID: 26027891 DOI: 10.1016/j.biotechadv.2015.05.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/27/2015] [Accepted: 05/27/2015] [Indexed: 12/11/2022]
Abstract
Due to global crises such as pollution and depletion of fossil fuels, sustainable technologies based on microbial cell-factories have been garnering great interest as an alternative to chemical factories. The development of microbial cell-factories is imperative in cutting down the overall manufacturing cost. Thus, diverse metabolic engineering strategies and engineering tools have been established to obtain a preferred genotype and phenotype displaying superior productivity. However, these tools are limited to only a handful of genes with permanent modification of a genome and significant labor costs, and this is one of the bottlenecks associated with biofactory construction. Therefore, a groundbreaking rapid and high-throughput engineering tool is needed for efficient construction of microbial cell-factories. During the last decade, copious small noncoding RNAs (ncRNAs) have been discovered in bacteria. These are involved in substantial regulatory roles like transcriptional and post-transcriptional gene regulation by modulating mRNA elongation, stability, or translational efficiency. Because of their vulnerability, ncRNAs can be used as another layer of conditional control over gene expression without modifying chromosomal sequences, and hence would be a promising high-throughput tool for metabolic engineering. Here, we review successful design principles and applications of ncRNAs for high-throughput metabolic engineering or physiological studies of diverse industrially important microorganisms.
Collapse
Affiliation(s)
- Amit Kumar Chaudhary
- Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea
| | - Dokyun Na
- School of Integrative Engineering, Chung-Ang University, 84 Heukseok-ro, Dongjak-gu, Seoul 156-756, Republic of Korea.
| | - Eun Yeol Lee
- Department of Chemical Engineering, Kyung Hee University, Gyeonggi-do 446-701, Republic of Korea.
| |
Collapse
|
24
|
Meyer AH, Dybala-Defratyka A, Alaimo PJ, Geronimo I, Sanchez AD, Cramer CJ, Elsner M. Cytochrome P450-catalyzed dealkylation of atrazine by Rhodococcus sp. strain NI86/21 involves hydrogen atom transfer rather than single electron transfer. Dalton Trans 2015; 43:12175-86. [PMID: 24851834 DOI: 10.1039/c4dt00891j] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cytochrome P450 enzymes are responsible for a multitude of natural transformation reactions. For oxidative N-dealkylation, single electron (SET) and hydrogen atom abstraction (HAT) have been debated as underlying mechanisms. Combined evidence from (i) product distribution and (ii) isotope effects indicate that HAT, rather than SET, initiates N-dealkylation of atrazine to desethyl- and desisopropylatrazine by the microorganism Rhodococcus sp. strain NI86/21. (i) Product analysis revealed a non-selective oxidation at both the αC and βC-atom of the alkyl chain, which is expected for a radical reaction, but not SET. (ii) Normal (13)C and (15)N as well as pronounced (2)H isotope effects (εcarbon: -4.0‰ ± 0.2‰; εnitrogen: -1.4‰ ± 0.3‰, KIEH: 3.6 ± 0.8) agree qualitatively with calculated values for HAT, whereas inverse (13)C and (15)N isotope effects are predicted for SET. Analogous results are observed with the Fe(iv)[double bond, length as m-dash]O model system [5,10,15,20-tetrakis(pentafluorophenyl)porphyrin-iron(iii)-chloride + NaIO4], but not with permanganate. These results emphasize the relevance of the HAT mechanism for N-dealkylation by P450.
Collapse
Affiliation(s)
- Armin H Meyer
- Institute of Groundwater Ecology, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany.
| | | | | | | | | | | | | |
Collapse
|
25
|
Evolution of a chimeric aspartate kinase for L-lysine production using a synthetic RNA device. Appl Microbiol Biotechnol 2015; 99:8527-36. [DOI: 10.1007/s00253-015-6615-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 03/20/2015] [Accepted: 04/15/2015] [Indexed: 10/23/2022]
|
26
|
Kadioglu O, Malczyk AH, Greten HJ, Efferth T. Aptamers as a novel tool for diagnostics and therapy. Invest New Drugs 2015; 33:513-20. [PMID: 25637166 DOI: 10.1007/s10637-015-0213-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 01/21/2015] [Indexed: 11/27/2022]
Abstract
Aptamers are short single-stranded DNA or RNA oligonucleotides that are capable of binding small molecules, proteins, or nucleotides with high specificity. They show a stable conformation and high binding affinity for their target molecules. There are numerous applications for aptamers in biotechnology, molecular diagnostics and targeted therapy of diseases. Their production is cheap, and they generally display lower immunogenicity than monoclonal antibodies. In the present review, we give an introduction to the preparation of aptamers and provide examples for their use in biotechnology, diagnostics and therapy of diseases.
Collapse
Affiliation(s)
- Onat Kadioglu
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, 55128, Mainz, Germany
| | | | | | | |
Collapse
|
27
|
|
28
|
Abstract
Photoresponsive artificial riboswitch has the potential to offer a de novo method for spatiotemporal control of gene expression in living cells. Because, even today, it is difficult to design a small molecule binding to a specific RNA sequence, generating an artificial riboswitch that possesses highly specific affinity to a ligand of interest basically depends on in vitro selection procedure where a variety of RNA-ligand complexes can be obtained in established methods. Here, we describe the protocol for in vitro aptamer selection against a photoresponsive peptide ligand containing azobenzene moiety that undergoes photoisomerization through light irradiation. Furthermore, we explain a procedure for surface plasmon resonance assay to detect photoswitchable association and dissociation of RNA-ligand complex on gold surface.
Collapse
|
29
|
Vincent HA, Robinson CJ, Wu MC, Dixon N, Micklefield J. Generation of orthogonally selective bacterial riboswitches by targeted mutagenesis and in vivo screening. Methods Mol Biol 2014; 1111:107-29. [PMID: 24549615 DOI: 10.1007/978-1-62703-755-6_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Riboswitches are naturally occurring RNA-based genetic switches that control gene expression in response to the binding of small-molecule ligands, typically through modulation of transcription or translation. Their simple mechanism of action and the expanding diversity of riboswitch classes make them attractive targets for the development of novel gene expression tools. The essential first step in realizing this potential is to generate artificial riboswitches that respond to nonnatural, synthetic ligands, thereby avoiding disruption of normal cellular function. Here we describe a strategy for engineering orthogonally selective riboswitches based on natural switches. The approach begins with saturation mutagenesis of the ligand-binding pocket of a naturally occurring riboswitch to generate a library of riboswitch mutants. These mutants are then screened in vivo against a synthetic compound library to identify functional riboswitch-ligand combinations. Promising riboswitch-ligand pairs are then further characterized both in vivo and in vitro. Using this method, a series of artificial riboswitches can be generated that are versatile synthetic biology tools for use in protein production, gene functional analysis, metabolic engineering, and other biotechnological applications.
Collapse
Affiliation(s)
- Helen A Vincent
- Manchester Institute of Biotechnology and School of Chemistry, The University of Manchester, Manchester, UK
| | | | | | | | | |
Collapse
|
30
|
Dotu I, Garcia-Martin JA, Slinger BL, Mechery V, Meyer MM, Clote P. Complete RNA inverse folding: computational design of functional hammerhead ribozymes. Nucleic Acids Res 2014; 42:11752-62. [PMID: 25209235 PMCID: PMC4191386 DOI: 10.1093/nar/gku740] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Nanotechnology and synthetic biology currently constitute one of the most innovative, interdisciplinary fields of research, poised to radically transform society in the 21st century. This paper concerns the synthetic design of ribonucleic acid molecules, using our recent algorithm, RNAiFold, which can determine all RNA sequences whose minimum free energy secondary structure is a user-specified target structure. Using RNAiFold, we design ten cis-cleaving hammerhead ribozymes, all of which are shown to be functional by a cleavage assay. We additionally use RNAiFold to design a functional cis-cleaving hammerhead as a modular unit of a synthetic larger RNA. Analysis of kinetics on this small set of hammerheads suggests that cleavage rate of computationally designed ribozymes may be correlated with positional entropy, ensemble defect, structural flexibility/rigidity and related measures. Artificial ribozymes have been designed in the past either manually or by SELEX (Systematic Evolution of Ligands by Exponential Enrichment); however, this appears to be the first purely computational design and experimental validation of novel functional ribozymes. RNAiFold is available at http://bioinformatics.bc.edu/clotelab/RNAiFold/.
Collapse
Affiliation(s)
- Ivan Dotu
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
| | | | - Betty L Slinger
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
| | - Vinodh Mechery
- Hofstra North Shore-LIJ School of Medicine, Hempstead, NY 11549, USA
| | - Michelle M Meyer
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
| | - Peter Clote
- Biology Department, Boston College, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
| |
Collapse
|
31
|
Hayat A, Marty JL. Aptamer based electrochemical sensors for emerging environmental pollutants. Front Chem 2014; 2:41. [PMID: 25019067 PMCID: PMC4071757 DOI: 10.3389/fchem.2014.00041] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/09/2014] [Indexed: 12/30/2022] Open
Abstract
Environmental contaminants monitoring is one of the key issues in understanding and managing hazards to human health and ecosystems. In this context, aptamer based electrochemical sensors have achieved intense significance because of their capability to resolve a potentially large number of problems and challenges in environmental contamination. An aptasensor is a compact analytical device incorporating an aptamer (oligonulceotide) as the sensing element either integrated within or intimately associated with a physiochemical transducer surface. Nucleic acid is well known for the function of carrying and passing genetic information, however, it has found a key role in analytical monitoring during recent years. Aptamer based sensors represent a novelty in environmental analytical science and there are great expectations for their promising performance as alternative to conventional analytical tools. This review paper focuses on the recent advances in the development of aptamer based electrochemical sensors for environmental applications with special emphasis on emerging pollutants.
Collapse
Affiliation(s)
- Akhtar Hayat
- BIOMEM, Université de Perpignan Perpignan, France ; Interdisciplinary Research Centre in Biomedical Materials, COMSATS Institute of Information Technology Lahore, Pakistan
| | - Jean L Marty
- BIOMEM, Université de Perpignan Perpignan, France
| |
Collapse
|
32
|
Iyer S, Doktycz MJ. Thrombin-mediated transcriptional regulation using DNA aptamers in DNA-based cell-free protein synthesis. ACS Synth Biol 2014; 3:340-6. [PMID: 24059754 DOI: 10.1021/sb4000756] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Realizing the potential of cell-free systems will require development of ligand-sensitive gene promoters that control gene expression in response to a ligand of interest. Here, we describe an approach to designing ligand-sensitive transcriptional control in cell-free systems that is based on the combination of a DNA aptamer that binds thrombin and the T7 bacteriophage promoter. Placement of the aptamer near the T7 promoter, and using a primarily single-stranded template, results in up to a 6-fold change in gene expression in a ligand concentration-dependent manner. We further demonstrate that the sensitivity to thrombin concentration and the fold change in expression can be tuned by altering the position of the aptamer. The results described here pave the way for the use of DNA aptamers to achieve modular regulation of transcription in response to a wide variety of ligands in cell-free systems.
Collapse
Affiliation(s)
- Sukanya Iyer
- Graduate
Program
in Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Mitchel J. Doktycz
- Graduate
Program
in Genome Science and Technology, University of Tennessee, Knoxville, Tennessee 37996, United States
- Biosciences
Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
- Center for
Nanophase
Materials Sciences, Oak Ridge National Laboratory, Bethel Valley Road, Oak Ridge, Tennessee 37831, United States
| |
Collapse
|
33
|
Walsh S, Gardner L, Deiters A, Williams GJ. Intracellular light-activation of riboswitch activity. Chembiochem 2014; 15:1346-51. [PMID: 24861567 DOI: 10.1002/cbic.201400024] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Indexed: 12/18/2022]
Abstract
By combining a riboswitch with a cell-permeable photocaged small-molecule ligand, an optochemical gene control element was constructed that enabled spatial and temporal control of gene expression in bacterial cells. The simplicity of this strategy, coupled with the ability to create synthetic riboswitches with tailored ligand specificities and output in a variety of microorganisms, plants, and fungi might afford a general strategy to photocontrol gene expression in vivo. The ability to activate riboswitches by using light enables the interrogation and manipulation of a wide range of biological processes with high precision, and will have broad utility in the regulation of artificial genetic circuits.
Collapse
Affiliation(s)
- Steven Walsh
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695-8204 (USA)
| | | | | | | |
Collapse
|
34
|
Hwang IY, Tan MH, Koh E, Ho CL, Poh CL, Chang MW. Reprogramming microbes to be pathogen-seeking killers. ACS Synth Biol 2014; 3:228-37. [PMID: 24020906 DOI: 10.1021/sb400077j] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Recent examples of new genetic circuits that enable cells to acquire biosynthetic capabilities, such as specific pathogen killing, present an attractive therapeutic application of synthetic biology. Herein, we demonstrate a novel genetic circuit that reprograms Escherichia coli to specifically recognize, migrate toward, and eradicate both dispersed and biofilm-encased pathogenic Pseudomonas aeruginosa cells. The reprogrammed E. coli degraded the mature biofilm matrix and killed the latent cells encapsulated within by expressing and secreting the antimicrobial peptide microcin S and the nuclease DNaseI upon the detection of quorum sensing molecules naturally secreted by P. aeruginosa. Furthermore, the reprogrammed E. coli exhibited directed motility toward the pathogen through regulated expression of CheZ in response to the quorum sensing molecules. By integrating the pathogen-directed motility with the dual antimicrobial activity in E. coli, we achieved signifincantly improved killing activity against planktonic and mature biofilm cells due to target localization, thus creating an active pathogen seeking killer E. coli.
Collapse
Affiliation(s)
- In Young Hwang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Mui Hua Tan
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Elvin Koh
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Chun Loong Ho
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Chueh Loo Poh
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| | - Matthew Wook Chang
- School of Chemical and Biomedical Engineering, Nanyang Technological University, 62
Nanyang Drive, Singapore 637459
| |
Collapse
|
35
|
|
36
|
Peselis A, Serganov A. Themes and variations in riboswitch structure and function. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:908-918. [PMID: 24583553 DOI: 10.1016/j.bbagrm.2014.02.012] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 02/14/2014] [Accepted: 02/20/2014] [Indexed: 11/19/2022]
Abstract
The complexity of gene expression control by non-coding RNA has been highlighted by the recent progress in the field of riboswitches. Discovered a decade ago, riboswitches represent a diverse group of non-coding mRNA regions that possess a unique ability to directly sense cellular metabolites and modulate gene expression through formation of alternative metabolite-free and metabolite-bound conformations. Such protein-free metabolite sensing domains utilize sophisticated three-dimensional folding of RNA molecules to discriminate between a cognate ligand from related compounds so that only the right ligand would trigger a genetic response. Given the variety of riboswitch ligands ranging from small cations to large coenzymes, riboswitches adopt a great diversity of structures. Although many riboswitches share structural principles to build metabolite-competent folds, form precise ligand-binding pockets, and communicate a ligand-binding event to downstream regulatory regions, virtually all riboswitch classes possess unique features for ligand recognition, even those tuned to recognize the same metabolites. Here we present an overview of the biochemical and structural research on riboswitches with a major focus on common principles and individual characteristics adopted by these regulatory RNA elements during evolution to specifically target small molecules and exert genetic responses. This article is part of a Special Issue entitled: Riboswitches.
Collapse
Affiliation(s)
- Alla Peselis
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Alexander Serganov
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA.
| |
Collapse
|
37
|
Sun EI, Rodionov DA. Computational analysis of riboswitch-based regulation. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1839:900-907. [PMID: 24583554 DOI: 10.1016/j.bbagrm.2014.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Revised: 01/28/2014] [Accepted: 02/18/2014] [Indexed: 11/17/2022]
Abstract
Advances in computational analysis of riboswitches in the last decade have contributed greatly to our understanding of riboswitch regulatory roles and mechanisms. Riboswitches were originally discovered as part of the sequence analysis of the 5'-untranslated region of mRNAs in the hope of finding novel gene regulatory sites, and the existence of structural RNAs appeared to be a spurious phenomenon. As more riboswitches were discovered, they illustrated the diversity and adaptability of these RNA regulatory sequences. The fact that a chemically monotonous molecule like RNA can discern a wide range of substrates and exert a variety of regulatory mechanisms was subsequently demonstrated in diverse genomes and has hastened the development of sophisticated algorithms for their analysis and prediction. In this review, we focus on some of the computational tools for riboswitch detection and secondary structure prediction. The study of this simple yet efficient form of gene regulation promises to provide a more complete picture of a world that RNA once dominated and allows rational design of artificial riboswitches. This article is part of a Special Issue entitled: Riboswitches.
Collapse
Affiliation(s)
- Eric I Sun
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093, USA
| | - Dmitry A Rodionov
- Sanford-Burnham Medical Research Institute, La Jolla, CA 92037, USA; A.A. Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127994, Russia.
| |
Collapse
|
38
|
Kang Z, Zhang C, Zhang J, Jin P, Zhang J, Du G, Chen J. Small RNA regulators in bacteria: powerful tools for metabolic engineering and synthetic biology. Appl Microbiol Biotechnol 2014; 98:3413-24. [DOI: 10.1007/s00253-014-5569-y] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 12/17/2022]
|
39
|
Abstract
Self-assembling RNA molecules present compelling substrates for the rational interrogation and control of living systems. However, imperfect in silico models--even at the secondary structure level--hinder the design of new RNAs that function properly when synthesized. Here, we present a unique and potentially general approach to such empirical problems: the Massive Open Laboratory. The EteRNA project connects 37,000 enthusiasts to RNA design puzzles through an online interface. Uniquely, EteRNA participants not only manipulate simulated molecules but also control a remote experimental pipeline for high-throughput RNA synthesis and structure mapping. We show herein that the EteRNA community leveraged dozens of cycles of continuous wet laboratory feedback to learn strategies for solving in vitro RNA design problems on which automated methods fail. The top strategies--including several previously unrecognized negative design rules--were distilled by machine learning into an algorithm, EteRNABot. Over a rigorous 1-y testing phase, both the EteRNA community and EteRNABot significantly outperformed prior algorithms in a dozen RNA secondary structure design tests, including the creation of dendrimer-like structures and scaffolds for small molecule sensors. These results show that an online community can carry out large-scale experiments, hypothesis generation, and algorithm design to create practical advances in empirical science.
Collapse
|
40
|
Nomura Y, Yokobayashi Y. Dual genetic selection of synthetic riboswitches in Escherichia coli. Methods Mol Biol 2014; 1111:131-140. [PMID: 24549616 DOI: 10.1007/978-1-62703-755-6_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This chapter describes a genetic selection strategy to engineer synthetic riboswitches that can chemically regulate gene expression in Escherichia coli. Riboswitch libraries are constructed by randomizing the nucleotides that potentially comprise an expression platform and fused to the hybrid selection/screening marker tetA-gfpuv. Iterative ON and OFF selections are performed under appropriate conditions that favor the survival or the growth of the cells harboring the desired riboswitches. After the selection, rapid screening of individual riboswitch clones is performed by measuring GFPuv fluorescence without subcloning. This optimized dual genetic selection strategy can be used to rapidly develop synthetic riboswitches without detailed computational design or structural knowledge.
Collapse
Affiliation(s)
- Yoko Nomura
- Department of Biomedical Engineering, University of California, Davis, Davis, CA, USA
| | | |
Collapse
|
41
|
Induction and reversal of myotonic dystrophy type 1 pre-mRNA splicing defects by small molecules. Nat Commun 2013; 4:2044. [PMID: 23806903 PMCID: PMC3710115 DOI: 10.1038/ncomms3044] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Accepted: 05/23/2013] [Indexed: 02/06/2023] Open
Abstract
The ability to control pre-mRNA splicing with small molecules could facilitate the development of therapeutics or cell-based circuits that control gene function. Myotonic dystrophy type 1 (DM1) is caused by the dysregulation of alternative pre-mRNA splicing due to sequestration of muscleblind-like 1 protein (MBNL1) by expanded, non-coding r(CUG) repeats (r(CUG)exp). Here we report two small molecules that induce or ameliorate alternative splicing dysregulation. The thiophene-containing small molecule (1) inhibits the interaction of MBNL1 with its natural pre-mRNA substrates. Compound (2), a substituted naphthyridine, binds r(CUG)exp and displaces MBNL1. Structural models show that 1 binds MBNL1 in the Zn-finger domain and that 2 interacts with UU loops in r(CUG)exp. This study provides a structural framework for small molecules that target MBNL1 by mimicking r(CUG)exp and shows that targeting MBNL1 causes dysregulation of alternative splicing, suggesting that MBNL1 is thus not a suitable therapeutic target for the treatment of DM1.
Collapse
|
42
|
Vazquez-Anderson J, Contreras LM. Regulatory RNAs: charming gene management styles for synthetic biology applications. RNA Biol 2013; 10:1778-97. [PMID: 24356572 DOI: 10.4161/rna.27102] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
RNAs have many important functional properties, including that they are independently controllable and highly tunable. As a result of these advantageous properties, their use in a myriad of sophisticated devices has been widely explored. Yet, the exploitation of RNAs for synthetic applications is highly dependent on the ability to characterize the many new molecules that continue to be discovered by large-scale sequencing and high-throughput screening techniques. In this review, we present an exhaustive survey of the most recent synthetic bacterial riboswitches and small RNAs while emphasizing their virtues in gene expression management. We also explore the use of these RNA components as building blocks in the RNA synthetic biology toolbox and discuss examples of synthetic RNA components used to rewire bacterial regulatory circuitry. We anticipate that this field will expand its catalog of smart devices by mimicking and manipulating natural RNA mechanisms and functions.
Collapse
Affiliation(s)
- Jorge Vazquez-Anderson
- McKetta Department of Chemical Engineering; University of Texas at Austin; Austin, TX USA
| | - Lydia M Contreras
- McKetta Department of Chemical Engineering; University of Texas at Austin; Austin, TX USA
| |
Collapse
|
43
|
Espah Borujeni A, Channarasappa AS, Salis HM. Translation rate is controlled by coupled trade-offs between site accessibility, selective RNA unfolding and sliding at upstream standby sites. Nucleic Acids Res 2013; 42:2646-59. [PMID: 24234441 PMCID: PMC3936740 DOI: 10.1093/nar/gkt1139] [Citation(s) in RCA: 329] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The ribosome's interactions with mRNA govern its translation rate and the effects of post-transcriptional regulation. Long, structured 5' untranslated regions (5' UTRs) are commonly found in bacterial mRNAs, though the physical mechanisms that determine how the ribosome binds these upstream regions remain poorly defined. Here, we systematically investigate the ribosome's interactions with structured standby sites, upstream of Shine-Dalgarno sequences, and show that these interactions can modulate translation initiation rates by over 100-fold. We find that an mRNA's translation initiation rate is controlled by the amount of single-stranded surface area, the partial unfolding of RNA structures to minimize the ribosome's binding free energy penalty, the absence of cooperative binding and the potential for ribosomal sliding. We develop a biophysical model employing thermodynamic first principles and a four-parameter free energy model to accurately predict the ribosome's translation initiation rates for 136 synthetic 5' UTRs with large structures, diverse shapes and multiple standby site modules. The model predicts and experiments confirm that the ribosome can readily bind distant standby site modules that support high translation rates, providing a physical mechanism for observed context effects and long-range post-transcriptional regulation.
Collapse
Affiliation(s)
- Amin Espah Borujeni
- Department of Chemical Engineering, Penn State University, University Park, PA 16802, USA and Department of Agricultural and Biological Engineering, Penn State University, University Park, PA 16802, USA
| | | | | |
Collapse
|
44
|
Ellefson JW, Meyer AJ, Hughes RA, Cannon JR, Brodbelt JS, Ellington AD. Directed evolution of genetic parts and circuits by compartmentalized partnered replication. Nat Biotechnol 2013; 32:97-101. [DOI: 10.1038/nbt.2714] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Accepted: 09/05/2013] [Indexed: 11/09/2022]
|
45
|
Characterization of a quorum sensing device for synthetic biology design: Experimental and modeling validation. Chem Eng Sci 2013. [DOI: 10.1016/j.ces.2012.12.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
46
|
Synthetic regulatory RNAs as tools for engineering biological systems: Design and applications. Chem Eng Sci 2013. [DOI: 10.1016/j.ces.2013.01.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
47
|
Iyer S, Karig DK, Norred SE, Simpson ML, Doktycz MJ. Multi-input regulation and logic with T7 promoters in cells and cell-free systems. PLoS One 2013; 8:e78442. [PMID: 24194933 PMCID: PMC3806817 DOI: 10.1371/journal.pone.0078442] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Accepted: 09/10/2013] [Indexed: 11/21/2022] Open
Abstract
Engineered gene circuits offer an opportunity to harness biological systems for biotechnological and biomedical applications. However, reliance on native host promoters for the construction of circuit elements, such as logic gates, can make the implementation of predictable, independently functioning circuits difficult. In contrast, T7 promoters offer a simple orthogonal expression system for use in a variety of cellular backgrounds and even in cell-free systems. Here we develop a T7 promoter system that can be regulated by two different transcriptional repressors for the construction of a logic gate that functions in cells and in cell-free systems. We first present LacI repressible T7lacO promoters that are regulated from a distal lac operator site for repression. We next explore the positioning of a tet operator site within the T7lacO framework to create T7 promoters that respond to tet and lac repressors and realize an IMPLIES gate. Finally, we demonstrate that these dual input sensitive promoters function in an E. coli cell-free protein expression system. Our results expand the utility of T7 promoters in cell based as well as cell-free synthetic biology applications.
Collapse
Affiliation(s)
- Sukanya Iyer
- Graduate Program in Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, Tennessee, United States of America
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - David K. Karig
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
| | - S. Elizabeth Norred
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee, United States of America
| | - Michael L. Simpson
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Department of Materials Science and Engineering, University of Tennessee, Knoxville, Knoxville, Tennessee, United States of America
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Knoxville, Tennessee, United States of America
| | - Mitchel J. Doktycz
- Graduate Program in Genome Science and Technology, University of Tennessee, Knoxville, Knoxville, Tennessee, United States of America
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee, United States of America
- * E-mail:
| |
Collapse
|
48
|
Long F, Zhu A, Shi H. Recent advances in optical biosensors for environmental monitoring and early warning. SENSORS (BASEL, SWITZERLAND) 2013; 13:13928-48. [PMID: 24132229 PMCID: PMC3859100 DOI: 10.3390/s131013928] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2013] [Revised: 09/20/2013] [Accepted: 10/05/2013] [Indexed: 01/30/2023]
Abstract
The growing number of pollutants requires the development of innovative analytical devices that are precise, sensitive, specific, rapid, and easy-to-use to meet the increasing demand for legislative actions on environmental pollution control and early warning. Optical biosensors, as a powerful alternative to conventional analytical techniques, enable the highly sensitive, real-time, and high-frequency monitoring of pollutants without extensive sample preparation. This article reviews important advances in functional biorecognition materials (e.g., enzymes, aptamers, DNAzymes, antibodies and whole cells) that facilitate the increasing application of optical biosensors. This work further examines the significant improvements in optical biosensor instrumentation and their environmental applications. Innovative developments of optical biosensors for environmental pollution control and early warning are also discussed.
Collapse
Affiliation(s)
- Feng Long
- School of Environment and Natural Resources, Renmin University of China, No.59, Zhongguancun Street, Haidian District, Beijing 100872, China
| | - Anna Zhu
- Research Institute of Chemical Defence, No.1, Huanyin Street, Changping District, Beijing 100872, China; E-Mail:
| | - Hanchang Shi
- State Key Joint Laboratory of ESPC, School of Environment, Tsinghua University, No.1, Tsinghua Yuan, Haidian District, Beijing 100872, China
| |
Collapse
|
49
|
Chappell J, Takahashi MK, Meyer S, Loughrey D, Watters KE, Lucks J. The centrality of RNA for engineering gene expression. Biotechnol J 2013; 8:1379-95. [PMID: 24124015 PMCID: PMC4033574 DOI: 10.1002/biot.201300018] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 07/19/2013] [Accepted: 08/15/2013] [Indexed: 12/25/2022]
Abstract
Synthetic biology holds promise as both a framework for rationally engineering biological systems and a way to revolutionize how we fundamentally understand them. Essential to realizing this promise is the development of strategies and tools to reliably and predictably control and characterize sophisticated patterns of gene expression. Here we review the role that RNA can play towards this goal and make a case for why this versatile, designable, and increasingly characterizable molecule is one of the most powerful substrates for engineering gene expression at our disposal. We discuss current natural and synthetic RNA regulators of gene expression acting at key points of control – transcription, mRNA degradation, and translation. We also consider RNA structural probing and computational RNA structure predication tools as a way to study RNA structure and ultimately function. Finally, we discuss how next-generation sequencing methods are being applied to the study of RNA and to the characterization of RNA's many properties throughout the cell.
Collapse
Affiliation(s)
- James Chappell
- School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, NY, USA
| | | | | | | | | | | |
Collapse
|
50
|
Abstract
Realization of a functional artificial cell, the so-called protocell, is a major challenge posed by synthetic biology. A subsequent goal is to use the protocellular units for the bottom-up assembly of prototissues. There is, however, a looming chasm in our knowledge between protocells and prototissues. In the present paper, we give a brief overview of the work on protocells to date, followed by a discussion on the rational design of key structural elements specific to linking two protocellular bilayers. We propose that designing synthetic parts capable of simultaneous insertion into two bilayers may be crucial in the hierarchical assembly of protocells into a functional prototissue.
Collapse
|