51
|
Choi YN, Shin YR, Park JM, Lee JW. Cell-Free Transcription-Coupled CRISPR/Cas12a Assay for Prototyping Cyanobacterial Promoters. ACS Synth Biol 2021; 10:1300-1307. [PMID: 34015913 DOI: 10.1021/acssynbio.1c00148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cyanobacteria are promising microbial hosts for the production of diverse biofuels and biochemicals. However, compared to other model microbial hosts such as Escherichia coli and yeast, it takes a long time to genetically modify cyanobacteria. One way to efficiently engineer cyanobacteria while minimizing genetic engineering would be to develop a fast, high-throughput prototyping tool for cyanobacteria. In this study, we developed a CRISPR/Cas12a-based assay coupled with cyanobacteria cell-free systems to rapidly prototype promoter characteristics. Using this newly developed assay, we demonstrated cyanobacteria cell-free transcription for the first time and confirmed a positive correlation between the in vitro and in vivo transcription performance. Furthermore, we generated a synthetic promoter library and evaluated the characteristics of promoter subregions by using the assay. Varied promoter strength derived from random mutations were rapidly and effectively measured in a high-throughput way. We believe that this study offers an easily applicable and rapid prototyping platform to characterize promoters for cyanobacterial engineering.
Collapse
Affiliation(s)
- Yun-Nam Choi
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
| | - Ye Rim Shin
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
| | - Jong Moon Park
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Environmental Science and Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Integrated Technology, Yonsei University (POSTECH-Yonsei Open Campus), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk, 37673, Korea
| | - Jeong Wook Lee
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk 37673, Korea
- School of Integrated Technology, Yonsei University (POSTECH-Yonsei Open Campus), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyungbuk, 37673, Korea
| |
Collapse
|
52
|
Lin CY, Feng Y, Ge J, Lu Y. Impact of Metal-Organic Frameworks on Protein Expression. Chem Res Toxicol 2021; 34:1403-1408. [PMID: 34101452 DOI: 10.1021/acs.chemrestox.1c00048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The influence of excessive metal-organic frameworks (MOFs) on the translation process was investigated in this study. Different concentrations and sizes of MOFs were tested through adding them to a cell-free expression system and observing the downstream expression signal. Furthermore, a proteomics analysis has been employed to explore and reveal the influence of MOFs on the protein expression, which can provide significant referential value for developing a delivery system with MOFs.
Collapse
Affiliation(s)
- Cheng-Yen Lin
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yi Feng
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Jun Ge
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| |
Collapse
|
53
|
Jiao C, Sharma S, Dugar G, Peeck NL, Bischler T, Wimmer F, Yu Y, Barquist L, Schoen C, Kurzai O, Sharma CM, Beisel CL. Noncanonical crRNAs derived from host transcripts enable multiplexable RNA detection by Cas9. Science 2021; 372:941-948. [PMID: 33906967 PMCID: PMC8224270 DOI: 10.1126/science.abe7106] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 04/09/2021] [Indexed: 12/19/2022]
Abstract
CRISPR-Cas systems recognize foreign genetic material using CRISPR RNAs (crRNAs). In type II systems, a trans-activating crRNA (tracrRNA) hybridizes to crRNAs to drive their processing and utilization by Cas9. While analyzing Cas9-RNA complexes from Campylobacter jejuni, we discovered tracrRNA hybridizing to cellular RNAs, leading to formation of "noncanonical" crRNAs capable of guiding DNA targeting by Cas9. Our discovery inspired the engineering of reprogrammed tracrRNAs that link the presence of any RNA of interest to DNA targeting with different Cas9 orthologs. This capability became the basis for a multiplexable diagnostic platform termed LEOPARD (leveraging engineered tracrRNAs and on-target DNAs for parallel RNA detection). LEOPARD allowed simultaneous detection of RNAs from different viruses in one test and distinguished severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its D614G (Asp614→Gly) variant with single-base resolution in patient samples.
Collapse
Affiliation(s)
- Chunlei Jiao
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Sahil Sharma
- Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg. 97080 Würzburg, Germany
| | - Gaurav Dugar
- Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg. 97080 Würzburg, Germany
| | - Natalia L Peeck
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Thorsten Bischler
- Core Unit Systems Medicine, University of Würzburg, 97080 Würzburg, Germany
| | - Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Yanying Yu
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
- Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
| | - Christoph Schoen
- Institute for Hygiene and Microbiology, University of Würzburg, 97080 Würzburg, Germany
| | - Oliver Kurzai
- Institute for Hygiene and Microbiology, University of Würzburg, 97080 Würzburg, Germany
- Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knoell-Institute, Jena, 07745 Germany
| | - Cynthia M Sharma
- Molecular Infection Biology II, Institute of Molecular Infection Biology, University of Würzburg. 97080 Würzburg, Germany.
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany.
- Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
| |
Collapse
|
54
|
Fackler N, Heijstra BD, Rasor BJ, Brown H, Martin J, Ni Z, Shebek KM, Rosin RR, Simpson SD, Tyo KE, Giannone RJ, Hettich RL, Tschaplinski TJ, Leang C, Brown SD, Jewett MC, Köpke M. Stepping on the Gas to a Circular Economy: Accelerating Development of Carbon-Negative Chemical Production from Gas Fermentation. Annu Rev Chem Biomol Eng 2021; 12:439-470. [PMID: 33872517 DOI: 10.1146/annurev-chembioeng-120120-021122] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Owing to rising levels of greenhouse gases in our atmosphere and oceans, climate change poses significant environmental, economic, and social challenges globally. Technologies that enable carbon capture and conversion of greenhouse gases into useful products will help mitigate climate change by enabling a new circular carbon economy. Gas fermentation usingcarbon-fixing microorganisms offers an economically viable and scalable solution with unique feedstock and product flexibility that has been commercialized recently. We review the state of the art of gas fermentation and discuss opportunities to accelerate future development and rollout. We discuss the current commercial process for conversion of waste gases to ethanol, including the underlying biology, challenges in process scale-up, and progress on genetic tool development and metabolic engineering to expand the product spectrum. We emphasize key enabling technologies to accelerate strain development for acetogens and other nonmodel organisms.
Collapse
Affiliation(s)
- Nick Fackler
- LanzaTech Inc., Skokie, Illinois 60077, USA; , , , , , ,
| | | | - Blake J Rasor
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , ,
| | - Hunter Brown
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , ,
| | - Jacob Martin
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , ,
| | - Zhuofu Ni
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , ,
| | - Kevin M Shebek
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , ,
| | - Rick R Rosin
- LanzaTech Inc., Skokie, Illinois 60077, USA; , , , , , ,
| | - Séan D Simpson
- LanzaTech Inc., Skokie, Illinois 60077, USA; , , , , , ,
| | - Keith E Tyo
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , ,
| | - Richard J Giannone
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA; ,
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA; ,
| | | | - Ching Leang
- LanzaTech Inc., Skokie, Illinois 60077, USA; , , , , , ,
| | - Steven D Brown
- LanzaTech Inc., Skokie, Illinois 60077, USA; , , , , , ,
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Chemistry of Life Processes Institute, and Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, USA; , , , , , , .,Robert H. Lurie Comprehensive Cancer Center and Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, USA
| | - Michael Köpke
- LanzaTech Inc., Skokie, Illinois 60077, USA; , , , , , ,
| |
Collapse
|
55
|
Kruyer NS, Sugianto W, Tickman BI, Alba Burbano D, Noireaux V, Carothers JM, Peralta-Yahya P. Membrane Augmented Cell-Free Systems: A New Frontier in Biotechnology. ACS Synth Biol 2021; 10:670-681. [PMID: 33749249 DOI: 10.1021/acssynbio.0c00625] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Membrane proteins are present in a wide array of cellular processes from primary and secondary metabolite synthesis to electron transport and single carbon metabolism. A key barrier to applying membrane proteins industrially is their difficult functional production. Beyond expression, folding, and membrane insertion, membrane protein activity is influenced by the physicochemical properties of the associated membrane, making it difficult to achieve optimal membrane protein performance outside the endogenous host. In this review, we highlight recent work on production of membrane proteins in membrane augmented cell-free systems (CFSs) and applications thereof. CFSs lack membranes and can thus be augmented with user-specified, tunable, mimetic membranes to generate customized environments for production of functional membrane proteins of interest. Membrane augmented CFSs would enable the synthesis of more complex plant secondary metabolites, the growth and division of synthetic cells for drug delivery and cell therapeutic applications, as well as enable green energy applications including methane capture and artificial photosynthesis.
Collapse
Affiliation(s)
- Nicholas S. Kruyer
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Widianti Sugianto
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| | - Benjamin I. Tickman
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington 98195, United States
| | - Diego Alba Burbano
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington 98195, United States
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - James M. Carothers
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington 98195, United States
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
| | - Pamela Peralta-Yahya
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332, United States
| |
Collapse
|
56
|
Collins SP, Rostain W, Liao C, Beisel CL. Sequence-independent RNA sensing and DNA targeting by a split domain CRISPR-Cas12a gRNA switch. Nucleic Acids Res 2021; 49:2985-2999. [PMID: 33619539 PMCID: PMC7968991 DOI: 10.1093/nar/gkab100] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 01/13/2021] [Accepted: 02/04/2021] [Indexed: 12/11/2022] Open
Abstract
CRISPR technologies increasingly require spatiotemporal and dosage control of nuclease activity. One promising strategy involves linking nuclease activity to a cell's transcriptional state by engineering guide RNAs (gRNAs) to function only after complexing with a ‘trigger’ RNA. However, standard gRNA switch designs do not allow independent selection of trigger and guide sequences, limiting gRNA switch application. Here, we demonstrate the modular design of Cas12a gRNA switches that decouples selection of these sequences. The 5′ end of the Cas12a gRNA is fused to two distinct and non-overlapping domains: one base pairs with the gRNA repeat, blocking formation of a hairpin required for Cas12a recognition; the other hybridizes to the RNA trigger, stimulating refolding of the gRNA repeat and subsequent gRNA-dependent Cas12a activity. Using a cell-free transcription-translation system and Escherichia coli, we show that designed gRNA switches can respond to different triggers and target different DNA sequences. Modulating the length and composition of the sensory domain altered gRNA switch performance. Finally, gRNA switches could be designed to sense endogenous RNAs expressed only under specific growth conditions, rendering Cas12a targeting activity dependent on cellular metabolism and stress. Our design framework thus further enables tethering of CRISPR activities to cellular states.
Collapse
Affiliation(s)
- Scott P Collins
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - William Rostain
- Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Univ Evry, Université Paris-Saclay, 91057 Évry, France
| | - Chunyu Liao
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), Josef-Schneider-Str. 2/D15, 97080 Würzburg, Germany
| | - Chase L Beisel
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA.,Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), Josef-Schneider-Str. 2/D15, 97080 Würzburg, Germany.,Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
| |
Collapse
|
57
|
Uslu M, Siyah P, Harvey AJ, Kocabaş F. Modulating Cas9 activity for precision gene editing. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 181:89-127. [PMID: 34127203 DOI: 10.1016/bs.pmbts.2021.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The CRISPR/Cas9 is a RNA-guided nuclease complex that can be specifically programmed to target a user-specified DNA sequence. It has been a powerful and effective tool of genome editing. However, off-target activity of the Cas9 nuclease limits its potential use in the correction of inherited diseases and bona fide gene editing. Various protein engineering and guide RNA selection strategies have been utilized to improve Cas9-based genome-editing specificity and efficiency. We, however, have not yet achieved a degree of safety such that Cas9 gene editing approaches could be applicable in clinical settings. Here, we discuss the recently developed and precise gene editing technologies based on spCas9. Furthermore, we describe Cas9 modulating tools to increase the fidelity of the CRISPR/Cas9 system. These studies suggest that there is still a need for pharmaceutical modulation of Cas9 activity during gene editing procedures. Pharmaceutical modulation of Cas9 nuclease activity at on-target or off-target genomic loci could 1 day allow researchers to develop robust and precise therapeutical strategies in gene editing.
Collapse
Affiliation(s)
- Merve Uslu
- Graduate School of Natural and Applied Sciences, Yeditepe University, Istanbul, Turkey; Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Pınar Siyah
- Graduate School of Natural and Applied Sciences, Yeditepe University, Istanbul, Turkey; Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Andrew John Harvey
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Fatih Kocabaş
- Graduate School of Natural and Applied Sciences, Yeditepe University, Istanbul, Turkey; Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey.
| |
Collapse
|
58
|
Walton RT, Hsu JY, Joung JK, Kleinstiver BP. Scalable characterization of the PAM requirements of CRISPR-Cas enzymes using HT-PAMDA. Nat Protoc 2021; 16:1511-1547. [PMID: 33547443 PMCID: PMC8063866 DOI: 10.1038/s41596-020-00465-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 11/18/2020] [Indexed: 12/23/2022]
Abstract
The continued expansion of the genome-editing toolbox necessitates methods to characterize important properties of CRISPR-Cas enzymes. One such property is the requirement for Cas proteins to recognize a protospacer-adjacent motif (PAM) in DNA target sites. The high-throughput PAM determination assay (HT-PAMDA) is a method that enables scalable characterization of the PAM preferences of different Cas proteins. Here, we provide a step-by-step protocol for the method, discuss experimental design considerations, and highlight how the method can be used to profile naturally occurring CRISPR-Cas9 enzymes, engineered derivatives with improved properties, orthologs of different classes (e.g., Cas12a), and even different platforms (e.g., base editors). A distinguishing feature of HT-PAMDA is that the enzymes are expressed in a cell type or organism of interest (e.g., mammalian cells), permitting scalable characterization and comparison of hundreds of enzymes in a relevant setting. HT-PAMDA does not require specialized equipment or expertise and is cost effective for multiplexed characterization of many enzymes. The protocol enables comprehensive PAM characterization of dozens or hundreds of Cas enzymes in parallel in <2 weeks.
Collapse
Affiliation(s)
- Russell T Walton
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Jonathan Y Hsu
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Molecular Pathology Unit, Center for Cancer Research and Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - J Keith Joung
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
- Molecular Pathology Unit, Center for Cancer Research and Center for Computational and Integrative Biology, Massachusetts General Hospital, Charlestown, MA, USA
- Department of Pathology, Harvard Medical School, Boston, MA, USA
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.
- Department of Pathology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
59
|
Collias D, Beisel CL. CRISPR technologies and the search for the PAM-free nuclease. Nat Commun 2021; 12:555. [PMID: 33483498 PMCID: PMC7822910 DOI: 10.1038/s41467-020-20633-y] [Citation(s) in RCA: 132] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/03/2020] [Indexed: 12/20/2022] Open
Abstract
The ever-expanding set of CRISPR technologies and their programmable RNA-guided nucleases exhibit remarkable flexibility in DNA targeting. However, this flexibility comes with an ever-present constraint: the requirement for a protospacer adjacent motif (PAM) flanking each target. While PAMs play an essential role in self/nonself discrimination by CRISPR-Cas immune systems, this constraint has launched a far-reaching expedition for nucleases with relaxed PAM requirements. Here, we review ongoing efforts toward realizing PAM-free nucleases through natural ortholog mining and protein engineering. We also address potential consequences of fully eliminating PAM recognition and instead propose an alternative nuclease repertoire covering all possible PAM sequences.
Collapse
Affiliation(s)
- Daphne Collias
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA
| | - Chase L Beisel
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695-7905, USA.
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), 97080, Würzburg, Germany.
- Medical Faculty, University of Würzburg, 97080, Würzburg, Germany.
| |
Collapse
|
60
|
Cole SD, Miklos AE, Chiao AC, Sun ZZ, Lux MW. Methodologies for preparation of prokaryotic extracts for cell-free expression systems. Synth Syst Biotechnol 2020; 5:252-267. [PMID: 32775710 PMCID: PMC7398980 DOI: 10.1016/j.synbio.2020.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Revised: 07/22/2020] [Accepted: 07/23/2020] [Indexed: 12/19/2022] Open
Abstract
Cell-free systems that mimic essential cell functions, such as gene expression, have dramatically expanded in recent years, both in terms of applications and widespread adoption. Here we provide a review of cell-extract methods, with a specific focus on prokaryotic systems. Firstly, we describe the diversity of Escherichia coli genetic strains available and their corresponding utility. We then trace the history of cell-extract methodology over the past 20 years, showing key improvements that lower the entry level for new researchers. Next, we survey the rise of new prokaryotic cell-free systems, with associated methods, and the opportunities provided. Finally, we use this historical perspective to comment on the role of methodology improvements and highlight where further improvements may be possible.
Collapse
Affiliation(s)
- Stephanie D. Cole
- US Army Combat Capabilities Development Command Chemical Biological Center, 8567 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010, USA
| | - Aleksandr E. Miklos
- US Army Combat Capabilities Development Command Chemical Biological Center, 8567 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010, USA
| | - Abel C. Chiao
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Synvitrobio Inc., San Francisco, CA, USA
| | - Zachary Z. Sun
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA
- Synvitrobio Inc., San Francisco, CA, USA
| | - Matthew W. Lux
- US Army Combat Capabilities Development Command Chemical Biological Center, 8567 Ricketts Point Road, Aberdeen Proving Ground, MD, 21010, USA
| |
Collapse
|
61
|
Aliaga Goltsman DS, Alexander LM, Devoto AE, Albers JB, Liu J, Butterfield CN, Brown CT, Thomas BC. Novel Type V-A CRISPR Effectors Are Active Nucleases with Expanded Targeting Capabilities. CRISPR J 2020; 3:454-461. [PMID: 33146573 PMCID: PMC7757703 DOI: 10.1089/crispr.2020.0043] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cas12a enzymes are quickly being adopted for use in a variety of genome-editing applications. These programmable nucleases are part of adaptive microbial immune systems, the natural diversity of which has been largely unexplored. Here, we identified novel families of Type V-A CRISPR nucleases through a large-scale analysis of metagenomes collected from a variety of complex environments, and developed representatives of these systems into gene-editing platforms. The nucleases display extensive protein variation and can be programmed by a single-guide RNA with specific motifs. The majority of these enzymes are part of systems recovered from uncultivated organisms, some of which also encode a divergent Type V effector. Biochemical analysis uncovered unexpected protospacer adjacent motif diversity, indicating that these systems will facilitate a variety of genome-engineering applications. The simplicity of guide sequences and activity in human cell lines suggest utility in gene and cell therapies.
Collapse
Affiliation(s)
| | | | | | | | - Jason Liu
- Metagenomi, Inc., Emeryville, California, USA
| | | | | | | |
Collapse
|
62
|
Gasiunas G, Young JK, Karvelis T, Kazlauskas D, Urbaitis T, Jasnauskaite M, Grusyte MM, Paulraj S, Wang PH, Hou Z, Dooley SK, Cigan M, Alarcon C, Chilcoat ND, Bigelyte G, Curcuru JL, Mabuchi M, Sun Z, Fuchs RT, Schildkraut E, Weigele PR, Jack WE, Robb GB, Venclovas Č, Siksnys V. A catalogue of biochemically diverse CRISPR-Cas9 orthologs. Nat Commun 2020; 11:5512. [PMID: 33139742 PMCID: PMC7606464 DOI: 10.1038/s41467-020-19344-1] [Citation(s) in RCA: 91] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/02/2020] [Indexed: 12/27/2022] Open
Abstract
Bacterial Cas9 nucleases from type II CRISPR-Cas antiviral defence systems have been repurposed as genome editing tools. Although these proteins are found in many microbes, only a handful of variants are used for these applications. Here, we use bioinformatic and biochemical analyses to explore this largely uncharacterized diversity. We apply cell-free biochemical screens to assess the protospacer adjacent motif (PAM) and guide RNA (gRNA) requirements of 79 Cas9 proteins, thus identifying at least 7 distinct gRNA classes and 50 different PAM sequence requirements. PAM recognition spans the entire spectrum of T-, A-, C-, and G-rich nucleotides, from single nucleotide recognition to sequence strings longer than 4 nucleotides. Characterization of a subset of Cas9 orthologs using purified components reveals additional biochemical diversity, including both narrow and broad ranges of temperature dependence, staggered-end DNA target cleavage, and a requirement for long stretches of homology between gRNA and DNA target. Our results expand the available toolset of RNA-programmable CRISPR-associated nucleases.
Collapse
Affiliation(s)
| | - Joshua K Young
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA.
| | - Tautvydas Karvelis
- Institute of Biotechnology, Vilnius University, Vilnius, LT-10257, Lithuania
| | - Darius Kazlauskas
- Institute of Biotechnology, Vilnius University, Vilnius, LT-10257, Lithuania
| | - Tomas Urbaitis
- CasZyme, Vilnius, LT-10257, Lithuania
- Institute of Biotechnology, Vilnius University, Vilnius, LT-10257, Lithuania
| | | | | | - Sushmitha Paulraj
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA
| | - Po-Hao Wang
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA
- Inari Agriculture, West Lafayette, IN, 47906, USA
| | - Zhenglin Hou
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA
| | - Shane K Dooley
- Department of Agricultural and Biosystems Engineering, Iowa State University, Ames, IA, 50011, USA
| | - Mark Cigan
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA
- Genus plc, Deforest, WI, 53532, USA
| | - Clara Alarcon
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA
| | - N Doane Chilcoat
- Department of Molecular Engineering, Corteva Agriscience™, Johnston, IA, 50131, USA
| | - Greta Bigelyte
- Institute of Biotechnology, Vilnius University, Vilnius, LT-10257, Lithuania
| | | | | | - Zhiyi Sun
- New England Biolabs, Ipswich, MA, 01938, USA
| | | | | | | | | | | | - Česlovas Venclovas
- Institute of Biotechnology, Vilnius University, Vilnius, LT-10257, Lithuania
| | - Virginijus Siksnys
- CasZyme, Vilnius, LT-10257, Lithuania.
- Institute of Biotechnology, Vilnius University, Vilnius, LT-10257, Lithuania.
| |
Collapse
|
63
|
Song G, Zhang F, Zhang X, Gao X, Zhu X, Fan D, Tian Y. AcrIIA5 Inhibits a Broad Range of Cas9 Orthologs by Preventing DNA Target Cleavage. Cell Rep 2020; 29:2579-2589.e4. [PMID: 31775029 DOI: 10.1016/j.celrep.2019.10.078] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 09/15/2019] [Accepted: 10/18/2019] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas9 is an adaptive immune system for prokaryotes to defend against invasive genetic elements such as phages and has been used as a powerful tool for genome editing and modulation. To overcome CRISPR immunity, phages encode anti-CRISPR proteins (Acrs) to inhibit Cas9, providing an efficient "off-switch" tool for Cas9-based applications. Here, we characterized AcrIIA5, which is a Cas9 inhibitor discovered in a virulent phage of Streptococcus thermophilus. We found that AcrIIA5 is a potent and broad-spectrum inhibitor of CRISPR-Cas9, which can inhibit diverse Cas9 orthologs of type II-A, type II-B, and type II-C. AcrIIA5 inhibits Cas9 by preventing DNA target cleavage, but DNA target binding of Cas9 is unaffected. Importantly, it can affect the activity of the RuvC nuclease domain of Cas9 independent of the HNH nuclease domain. Our work expands the diversity of the inhibitory mechanisms used by Acrs and provides the guidance for developing controlling tools in Cas9-based applications.
Collapse
Affiliation(s)
- Guoxu Song
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Fei Zhang
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xuewen Zhang
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xing Gao
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoxiao Zhu
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Dongdong Fan
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yong Tian
- CAS Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
| |
Collapse
|
64
|
Yim SS, Johns NI, Noireaux V, Wang HH. Protecting Linear DNA Templates in Cell-Free Expression Systems from Diverse Bacteria. ACS Synth Biol 2020; 9:2851-2855. [PMID: 32926785 DOI: 10.1021/acssynbio.0c00277] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Recent advances in cell-free systems have opened up new capabilities in synthetic biology from rapid prototyping of genetic circuits and metabolic pathways to portable diagnostics and biomanufacturing. A current bottleneck in cell-free systems, especially those employing non-E. coli bacterial species, is the required use of plasmid DNA, which can be laborious to construct, clone, and verify. Linear DNA templates offer a faster and more direct route for many cell-free applications, but they are often rapidly degraded in cell-free reactions. In this study, we evaluated GamS from λ-phage, DNA fragments containing Chi-sites, and Ku from Mycobacterium tuberculosis for their ability to protect linear DNA templates in diverse bacterial cell-free systems. We show that these nuclease inhibitors exhibit differential protective activities against endogenous exonucleases in five different cell-free lysates, highlighting their utility for diverse bacterial species. We expect these linear DNA protection strategies will accelerate high-throughput approaches in cell-free synthetic biology.
Collapse
Affiliation(s)
- Sung Sun Yim
- Department of Systems Biology, Columbia University, New York, New York 10027, United States
| | - Nathan I. Johns
- Department of Systems Biology, Columbia University, New York, New York 10027, United States
- Integrated Program in Cellular, Molecular, and Biomedical Studies, Columbia University, New York, New York 10027, United States
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Harris H. Wang
- Department of Systems Biology, Columbia University, New York, New York 10027, United States
- Department of Pathology and Cell Biology, Columbia University, New York, New York 10027, United States
| |
Collapse
|
65
|
Yu L, Marchisio MA. Types I and V Anti-CRISPR Proteins: From Phage Defense to Eukaryotic Synthetic Gene Circuits. Front Bioeng Biotechnol 2020; 8:575393. [PMID: 33102460 PMCID: PMC7556299 DOI: 10.3389/fbioe.2020.575393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/31/2020] [Indexed: 12/26/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins), a prokaryotic RNA-mediated adaptive immune system, has been repurposed for gene editing and synthetic gene circuit construction both in bacterial and eukaryotic cells. In the last years, the emergence of the anti-CRISPR proteins (Acrs), which are natural OFF-switches for CRISPR-Cas, has provided a new means to control CRISPR-Cas activity and promoted a further development of CRISPR-Cas-based biotechnological toolkits. In this review, we focus on type I and type V-A anti-CRISPR proteins. We first narrate Acrs discovery and analyze their inhibitory mechanisms from a structural perspective. Then, we describe their applications in gene editing and transcription regulation. Finally, we discuss the potential future usage-and corresponding possible challenges-of these two kinds of anti-CRISPR proteins in eukaryotic synthetic gene circuits.
Collapse
|
66
|
Garcia B, Lee J, Edraki A, Hidalgo-Reyes Y, Erwood S, Mir A, Trost CN, Seroussi U, Stanley SY, Cohn RD, Claycomb JM, Sontheimer EJ, Maxwell KL, Davidson AR. Anti-CRISPR AcrIIA5 Potently Inhibits All Cas9 Homologs Used for Genome Editing. Cell Rep 2020; 29:1739-1746.e5. [PMID: 31722192 PMCID: PMC6910239 DOI: 10.1016/j.celrep.2019.10.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 08/24/2019] [Accepted: 10/03/2019] [Indexed: 11/03/2022] Open
Abstract
CRISPR-Cas9 systems provide powerful tools for genome editing. However, optimal employment of this technology will require control of Cas9 activity so that the timing, tissue specificity, and accuracy of editing may be precisely modulated. Anti-CRISPR proteins, which are small, naturally occurring inhibitors of CRISPR-Cas systems, are well suited for this purpose. A number of anti-CRISPR proteins have been shown to potently inhibit subgroups of CRISPR-Cas9 systems, but their maximal inhibitory activity is generally restricted to specific Cas9 homologs. Since Cas9 homologs vary in important properties, differing Cas9s may be optimal for particular genome-editing applications. To facilitate the practical exploitation of multiple Cas9 homologs, here we identify one anti-CRISPR, called AcrIIA5, that potently inhibits nine diverse type II-A and type II-C Cas9 homologs, including those currently used for genome editing. We show that the activity of AcrIIA5 results in partial in vivo cleavage of a single-guide RNA (sgRNA), suggesting that its mechanism involves RNA interaction.
Collapse
Affiliation(s)
- Bianca Garcia
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Jooyoung Lee
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Alireza Edraki
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Yurima Hidalgo-Reyes
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Steven Erwood
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada
| | - Aamir Mir
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Chantel N Trost
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Uri Seroussi
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Sabrina Y Stanley
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Ronald D Cohn
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children Research Institute, Toronto, ON M5G 0A4, Canada; Department of Pediatrics, University of Toronto and The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Julie M Claycomb
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada
| | - Erik J Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, MA 01605, USA; Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Karen L Maxwell
- Department of Biochemistry, University of Toronto, Toronto, ON M5G 1M1, Canada.
| | - Alan R Davidson
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5G 1M1, Canada.
| |
Collapse
|
67
|
Jacobsen T, Ttofali F, Liao C, Manchalu S, Gray BN, Beisel CL. Characterization of Cas12a nucleases reveals diverse PAM profiles between closely-related orthologs. Nucleic Acids Res 2020; 48:5624-5638. [PMID: 32329776 PMCID: PMC7261169 DOI: 10.1093/nar/gkaa272] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 04/05/2020] [Accepted: 04/07/2020] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems comprise diverse adaptive immune systems in prokaryotes whose RNA-directed nucleases have been co-opted for various technologies. Recent efforts have focused on expanding the number of known CRISPR-Cas subtypes to identify nucleases with novel properties. However, the functional diversity of nucleases within each subtype remains poorly explored. Here, we used cell-free transcription-translation systems and human cells to characterize six Cas12a single-effector nucleases from the V-A subtype, including nucleases sharing high sequence identity. While these nucleases readily utilized each other's guide RNAs, they exhibited distinct PAM profiles and apparent targeting activities that did not track based on phylogeny. In particular, two Cas12a nucleases encoded by Prevotella ihumii (PiCas12a) and Prevotella disiens (PdCas12a) shared over 95% amino-acid identity yet recognized distinct PAM profiles, with PiCas12a but not PdCas12a accommodating multiple G's in PAM positions -2 through -4 and T in position -1. Mutational analyses transitioning PiCas12a to PdCas12a resulted in PAM profiles distinct from either nuclease, allowing more flexible editing in human cells. Cas12a nucleases therefore can exhibit widely varying properties between otherwise related orthologs, suggesting selective pressure to diversify PAM recognition and supporting expansion of the CRISPR toolbox through ortholog mining and PAM engineering.
Collapse
Affiliation(s)
- Thomas Jacobsen
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Fani Ttofali
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Chunyu Liao
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Srinivas Manchalu
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | | | - Chase L Beisel
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA.,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany.,Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
| |
Collapse
|
68
|
Zhang L, Guo W, Lu Y. Advances in Cell‐Free Biosensors: Principle, Mechanism, and Applications. Biotechnol J 2020; 15:e2000187. [DOI: 10.1002/biot.202000187] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 06/22/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Liyuan Zhang
- Key Laboratory of Industrial Biocatalysis Ministry of Education Department of Chemical Engineering Tsinghua University Beijing 100084 China
- Department of Ecology Shenyang Agricultural University Shenyang Liaoning Province 110866 China
| | - Wei Guo
- Department of Ecology Shenyang Agricultural University Shenyang Liaoning Province 110866 China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis Ministry of Education Department of Chemical Engineering Tsinghua University Beijing 100084 China
| |
Collapse
|
69
|
Davidson AR, Lu WT, Stanley SY, Wang J, Mejdani M, Trost CN, Hicks BT, Lee J, Sontheimer EJ. Anti-CRISPRs: Protein Inhibitors of CRISPR-Cas Systems. Annu Rev Biochem 2020; 89:309-332. [PMID: 32186918 PMCID: PMC9718424 DOI: 10.1146/annurev-biochem-011420-111224] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) together with their accompanying cas (CRISPR-associated) genes are found frequently in bacteria and archaea, serving to defend against invading foreign DNA, such as viral genomes. CRISPR-Cas systems provide a uniquely powerful defense because they can adapt to newly encountered genomes. The adaptive ability of these systems has been exploited, leading to their development as highly effective tools for genome editing. The widespread use of CRISPR-Cas systems has driven a need for methods to control their activity. This review focuses on anti-CRISPRs (Acrs), proteins produced by viruses and other mobile genetic elements that can potently inhibit CRISPR-Cas systems. Discovered in 2013, there are now 54 distinct families of these proteins described, and the functional mechanisms of more than a dozen have been characterized in molecular detail. The investigation of Acrs is leading to a variety of practical applications and is providing exciting new insight into the biology of CRISPR-Cas systems.
Collapse
Affiliation(s)
- Alan R Davidson
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , , ,
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , ,
| | - Wang-Ting Lu
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , ,
| | - Sabrina Y Stanley
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , , ,
| | - Jingrui Wang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , , ,
| | - Marios Mejdani
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , ,
| | - Chantel N Trost
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , , ,
| | - Brian T Hicks
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5G 1M1, Canada; , ,
| | - Jooyoung Lee
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA; ,
| | - Erik J Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA; ,
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| |
Collapse
|
70
|
Marshall R, Beisel CL, Noireaux V. Rapid Testing of CRISPR Nucleases and Guide RNAs in an E. coli Cell-Free Transcription-Translation System. STAR Protoc 2020; 1:100003. [PMID: 33111065 PMCID: PMC7580202 DOI: 10.1016/j.xpro.2019.100003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
We present a protocol to rapidly test DNA binding and cleavage activity by CRISPR nucleases using cell-free transcription-translation (TXTL). Nuclease activity is assessed by adding DNA encoding a nuclease, a guide RNA, and a targeted reporter to a TXTL reaction and by measuring the fluorescence for several h. The reactions, performed in a few microliters, allow for parallel testing of many nucleases and guide RNAs. The protocol includes representative results for (d)Cas9 from Streptococcus pyogenes targeting a GFP reporter gene. For complete information on the generation and use of this protocol, please refer to the paper by Marshall et al. (2018).
Collapse
Affiliation(s)
- Ryan Marshall
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN 55455, USA
| | - Chase L. Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection Research, 97080 Würzburg, Germany
- Medical Faculty, University of Würzburg, Würzburg, Germany
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN 55455, USA
| |
Collapse
|
71
|
Parveen S, Akhtar N, Ghauri MA, Akhtar K. Conventional genetic manipulation of desulfurizing bacteria and prospects of using CRISPR-Cas systems for enhanced desulfurization activity. Crit Rev Microbiol 2020; 46:300-320. [PMID: 32530374 DOI: 10.1080/1040841x.2020.1772195] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Highly active and stable biocatalysts are the prerequisite for industrial scale application of the biodesulfurization process. Scientists are making efforts for increasing the desulfurizing activity of native strains by employing various genetic engineering approaches. Nevertheless, the achieved desulfurization rate is lower than the industrial requirements. Thus, there is a dire need to use efficient genetic tools for precise genome editing of desulfurizing bacteria for enhanced efficiency. In comparison to the previously used genetic engineering tools the newly developed CRISPR-Cas is a more efficient and simple genetic tool that has been successfully applied for targeted genome modification of eukaryotes as well as prokaryotes. In this paper, we have reviewed the approaches, previously used to enhance the biodesulfurization rates of the sulfur metabolizing microorganisms and have discussed the potential of CRISPR-Cas systems in engineering desulfurizing biocatalysts. We have also proposed a model to construct competent desulfurizing recombinants involving use of CRISPR-Cas technology. The model can be used to over-express the dsz genes under a constitutive promoter in a suitable heterologous host, to get a steady expression of desulfurization pathway. This may serve as an inducement to develop better performing desulfurizing recombinant strains using CRISPR-Cas systems, which can be helpful in increasing the rate of biodesulfurization in future.
Collapse
Affiliation(s)
- Sana Parveen
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences (PIEAS), Faisalabad, Pakistan
| | - Nasrin Akhtar
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences (PIEAS), Faisalabad, Pakistan
| | - Muhammad A Ghauri
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences (PIEAS), Faisalabad, Pakistan
| | - Kalsoom Akhtar
- Industrial Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE), Constituent College of Pakistan Institute of Engineering and Applied Sciences (PIEAS), Faisalabad, Pakistan
| |
Collapse
|
72
|
Abstract
The cell-free molecular synthesis of biochemical systems is a rapidly growing field of research. Advances in the Human Genome Project, DNA synthesis, and other technologies have allowed the in vitro construction of biochemical systems, termed cell-free biology, to emerge as an exciting domain of bioengineering. Cell-free biology ranges from the molecular to the cell-population scales, using an ever-expanding variety of experimental platforms and toolboxes. In this review, we discuss the ongoing efforts undertaken in the three major classes of cell-free biology methodologies, namely protein-based, nucleic acids–based, and cell-free transcription–translation systems, and provide our perspectives on the current challenges as well as the major goals in each of the subfields.
Collapse
Affiliation(s)
- Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Allen P. Liu
- Departments of Mechanical Engineering, Biomedical Engineering, Biophysics, and the Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan 48109, USA
| |
Collapse
|
73
|
Jacobsen T, Liao C, Beisel CL. The Acidaminococcus sp. Cas12a nuclease recognizes GTTV and GCTV as non-canonical PAMs. FEMS Microbiol Lett 2020; 366:5475644. [PMID: 31004485 DOI: 10.1093/femsle/fnz085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Accepted: 04/19/2019] [Indexed: 12/19/2022] Open
Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR)-associated (Cas) nuclease Acidaminococcus sp. Cas12a (AsCas12a, also known as AsCpf1) has become a popular alternative to Cas9 for genome editing and other applications. AsCas12a has been associated with a TTTV protospacer-adjacent motif (PAM) as part of target recognition. Using a cell-free transcription-translation (TXTL)-based PAM screen, we discovered that AsCas12a can also recognize GTTV and, to a lesser degree, GCTV motifs. Validation experiments involving DNA cleavage in TXTL, plasmid clearance in Escherichia coli, and indel formation in mammalian cells showed that AsCas12a was able to recognize these motifs, with the GTTV motif resulting in higher cleavage efficiency compared to the GCTV motif. We also observed that the -5 position influenced the activity of DNA cleavage in TXTL and in E. coli, with a C at this position resulting in the lowest activity. Together, these results show that wild-type AsCas12a can recognize non-canonical GTTV and GCTV motifs and exemplify why the range of PAMs recognized by Cas nucleases are poorly captured with a consensus sequence.
Collapse
Affiliation(s)
- Thomas Jacobsen
- Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC 27695, USA
| | - Chunyu Liao
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Josef-Schnedier-Str. 2, 97080 Würzburg, Germany
| | - Chase L Beisel
- Department of Chemical and Biomolecular Engineering, North Carolina State University, 911 Partners Way, Raleigh, NC 27695, USA.,Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Josef-Schnedier-Str. 2, 97080 Würzburg, Germany.,Medical Faculty, University of Würzburg, Josef-Schneider-Str. 2, 97080 Würzburg, Germany
| |
Collapse
|
74
|
Specht DA, Xu Y, Lambert G. Massively parallel CRISPRi assays reveal concealed thermodynamic determinants of dCas12a binding. Proc Natl Acad Sci U S A 2020; 117:11274-11282. [PMID: 32376630 PMCID: PMC7260945 DOI: 10.1073/pnas.1918685117] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The versatility of CRISPR-Cas endonucleases as a tool for biomedical research has led to diverse applications in gene editing, programmable transcriptional control, and nucleic acid detection. Most CRISPR-Cas systems, however, suffer from off-target effects and unpredictable nonspecific binding that negatively impact their reliability and broader applicability. To better evaluate the impact of mismatches on DNA target recognition and binding, we develop a massively parallel CRISPR interference (CRISPRi) assay to measure the binding energy between tens of thousands of CRISPR RNA (crRNA) and target DNA sequences. By developing a general thermodynamic model of CRISPR-Cas binding dynamics, our results unravel a comprehensive map of the energetic landscape of nuclease-dead Cas12a (dCas12a) from Francisella novicida as it inspects and binds to its DNA target. Our results reveal concealed thermodynamic factors affecting dCas12a DNA binding, which should guide the design and optimization of crRNA that limits off-target effects, including the crucial role of an extended protospacer adjacent motif (PAM) sequence and the impact of the specific base composition of crRNA-DNA mismatches. Our generalizable approach should also provide a mechanistic understanding of target recognition and DNA binding when applied to other CRISPR-Cas systems.
Collapse
Affiliation(s)
- David A Specht
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853
| | - Yasu Xu
- Field of Biophysics, Cornell University, Ithaca, NY 14853
| | - Guillaume Lambert
- School of Applied and Engineering Physics, Cornell University, Ithaca, NY 14853;
| |
Collapse
|
75
|
Roberts A, Barrangou R. Applications of CRISPR-Cas systems in lactic acid bacteria. FEMS Microbiol Rev 2020; 44:523-537. [DOI: 10.1093/femsre/fuaa016] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 05/18/2020] [Indexed: 12/26/2022] Open
Abstract
ABSTRACT
As a phenotypically and phylogenetically diverse group, lactic acid bacteria are found in a variety of natural environments and occupy important roles in medicine, biotechnology, food and agriculture. The widespread use of lactic acid bacteria across these industries fuels the need for new and functionally diverse strains that may be utilized as starter cultures or probiotics. Originally characterized in lactic acid bacteria, CRISPR-Cas systems and derived molecular machines can be used natively or exogenously to engineer new strains with enhanced functional attributes. Research on CRISPR-Cas biology and its applications has exploded over the past decade with studies spanning from the initial characterization of CRISPR-Cas immunity in Streptococcus thermophilus to the use of CRISPR-Cas for clinical gene therapies. Here, we discuss CRISPR-Cas classification, overview CRISPR biology and mechanism of action, and discuss current and future applications in lactic acid bacteria, opening new avenues for their industrial exploitation and manipulation of microbiomes.
Collapse
Affiliation(s)
- Avery Roberts
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Campus Box 7624, Raleigh, NC 27695, USA
- Genomic Sciences Graduate Program, North Carolina State University, Campus Box 7566, Raleigh, NC 27695, USA
| | - Rodolphe Barrangou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Campus Box 7624, Raleigh, NC 27695, USA
- Genomic Sciences Graduate Program, North Carolina State University, Campus Box 7566, Raleigh, NC 27695, USA
| |
Collapse
|
76
|
Abstract
CRISPR-Cas systems have been engineered as powerful tools to control gene expression in bacteria. The most common strategy relies on the use of Cas effectors modified to bind target DNA without introducing DNA breaks. These effectors can either block the RNA polymerase or recruit it through activation domains. Here, we discuss the mechanistic details of how Cas effectors can modulate gene expression by blocking transcription initiation or acting as transcription roadblocks. CRISPR-Cas tools can be further engineered to obtain fine-tuned control of gene expression or target multiple genes simultaneously. Several caveats in using these tools have also been revealed, including off-target effects and toxicity, making it important to understand the design rules of engineered CRISPR-Cas effectors in bacteria. Alternatively, some types of CRISPR-Cas systems target RNA and could be used to block gene expression at the posttranscriptional level. Finally, we review applications of these tools in high-throughput screens and the progress and challenges in introducing CRISPR knockdown to other species, including nonmodel bacteria with industrial or clinical relevance. A deep understanding of how CRISPR-Cas systems can be harnessed to control gene expression in bacteria and build powerful tools will certainly open novel research directions.
Collapse
Affiliation(s)
- Antoine Vigouroux
- Synthetic Biology, Institut Pasteur, Paris, France
- Microbial Morphogenesis and Growth, Institut Pasteur, Paris, France
| | - David Bikard
- Synthetic Biology, Institut Pasteur, Paris, France
| |
Collapse
|
77
|
Jaiswal S, Shukla P. Alternative Strategies for Microbial Remediation of Pollutants via Synthetic Biology. Front Microbiol 2020; 11:808. [PMID: 32508759 PMCID: PMC7249858 DOI: 10.3389/fmicb.2020.00808] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Accepted: 04/06/2020] [Indexed: 12/13/2022] Open
Abstract
Continuous contamination of the environment with xenobiotics and related recalcitrant compounds has emerged as a serious pollution threat. Bioremediation is the key to eliminating persistent contaminants from the environment. Traditional bioremediation processes show limitations, therefore it is necessary to discover new bioremediation technologies for better results. In this review we provide an outlook of alternative strategies for bioremediation via synthetic biology, including exploring the prerequisites for analysis of research data for developing synthetic biological models of microbial bioremediation. Moreover, cell coordination in synthetic microbial community, cell signaling, and quorum sensing as engineered for enhanced bioremediation strategies are described, along with promising gene editing tools for obtaining the host with target gene sequences responsible for the degradation of recalcitrant compounds. The synthetic genetic circuit and two-component regulatory system (TCRS)-based microbial biosensors for detection and bioremediation are also briefly explained. These developments are expected to increase the efficiency of bioremediation strategies for best results.
Collapse
|
78
|
Lin X, Zhou C, Zhu S, Deng H, Zhang J, Lu Y. O 2-Tuned Protein Synthesis Machinery in Escherichia coli-Based Cell-Free System. Front Bioeng Biotechnol 2020; 8:312. [PMID: 32328487 PMCID: PMC7160232 DOI: 10.3389/fbioe.2020.00312] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 03/23/2020] [Indexed: 12/18/2022] Open
Abstract
Involved in most aerobic biochemical processes, oxygen affects cellular functions, and organism behaviors. Protein synthesis, as the underlying biological process, is unavoidably affected by the regulation of oxygen delivery and utilization. Bypassing the cell wall, cell-free protein synthesis (CFPS) systems are well adopted for the precise oxygen regulation analysis of bioprocesses. Here a reliable flow platform was developed for measuring and analyzing the oxygen regulation on the protein synthesis processes by combining Escherichia coli-based CFPS systems and a tube-in-tube reactor. This platform allows protein synthesis reactions conducted in precisely controlled oxygen concentrations. For analysis of the intrinsic role of oxygen in protein synthesis, O2-tuned CFPS systems were explored with transcription-translation related parameters (transcripts, energy, reactive oxygen species, and proteomic pathway analysis). It was found that 2% of oxygen was the minimum requirement for protein synthesis. There was translation-related protein degradation in the high oxygen condition leading to a reduction. By combining the precise gas level controlling and open biosystems, this platform is also potential for fundamental understanding and clinical applications by diverse gas regulation in biological processes.
Collapse
Affiliation(s)
- Xiaomei Lin
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Caijin Zhou
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Songbiao Zhu
- Ministry of Education Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Haiteng Deng
- Ministry of Education Key Laboratory of Bioinformatics, Center for Synthetic and Systematic Biology, School of Life Sciences, Tsinghua University, Beijing, China
| | - Jisong Zhang
- The State Key Lab of Chemical Engineering, Department of Chemical Engineering, Tsinghua University, Beijing, China
| | - Yuan Lu
- Key Laboratory of Industrial Biocatalysis, Ministry of Education, Department of Chemical Engineering, Tsinghua University, Beijing, China
| |
Collapse
|
79
|
Watters KE, Shivram H, Fellmann C, Lew RJ, McMahon B, Doudna JA. Potent CRISPR-Cas9 inhibitors from Staphylococcus genomes. Proc Natl Acad Sci U S A 2020; 117:6531-6539. [PMID: 32156733 PMCID: PMC7104187 DOI: 10.1073/pnas.1917668117] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Anti-CRISPRs (Acrs) are small proteins that inhibit the RNA-guided DNA targeting activity of CRISPR-Cas enzymes. Encoded by bacteriophage and phage-derived bacterial genes, Acrs prevent CRISPR-mediated inhibition of phage infection and can also block CRISPR-Cas-mediated genome editing in eukaryotic cells. To identify Acrs capable of inhibiting Staphylococcus aureus Cas9 (SauCas9), an alternative to the most commonly used genome editing protein Streptococcus pyogenes Cas9 (SpyCas9), we used both self-targeting CRISPR screening and guilt-by-association genomic search strategies. Here we describe three potent inhibitors of SauCas9 that we name AcrIIA13, AcrIIA14, and AcrIIA15. These inhibitors share a conserved N-terminal sequence that is dispensable for DNA cleavage inhibition and have divergent C termini that are required in each case for inhibition of SauCas9-catalyzed DNA cleavage. In human cells, we observe robust inhibition of SauCas9-induced genome editing by AcrIIA13 and moderate inhibition by AcrIIA14 and AcrIIA15. We also find that the conserved N-terminal domain of AcrIIA13-AcrIIA15 binds to an inverted repeat sequence in the promoter of these Acr genes, consistent with its predicted helix-turn-helix DNA binding structure. These data demonstrate an effective strategy for Acr discovery and establish AcrIIA13-AcrIIA15 as unique bifunctional inhibitors of SauCas9.
Collapse
Affiliation(s)
- Kyle E Watters
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Haridha Shivram
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Christof Fellmann
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA 94158
- Department of Cellular and Molecular Pharmacology, School of Medicine, University of California, San Francisco, CA 94158
| | - Rachel J Lew
- Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA 94158
| | - Blake McMahon
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720;
- Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA 94158
- Department of Chemistry, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
- Innovative Genomics Institute, University of California, Berkeley, CA 94720
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
| |
Collapse
|
80
|
Hammerling MJ, Krüger A, Jewett MC. Strategies for in vitro engineering of the translation machinery. Nucleic Acids Res 2020; 48:1068-1083. [PMID: 31777928 PMCID: PMC7026604 DOI: 10.1093/nar/gkz1011] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/07/2019] [Accepted: 10/17/2019] [Indexed: 01/06/2023] Open
Abstract
Engineering the process of molecular translation, or protein biosynthesis, has emerged as a major opportunity in synthetic and chemical biology to generate novel biological insights and enable new applications (e.g. designer protein therapeutics). Here, we review methods for engineering the process of translation in vitro. We discuss the advantages and drawbacks of the two major strategies-purified and extract-based systems-and how they may be used to manipulate and study translation. Techniques to engineer each component of the translation machinery are covered in turn, including transfer RNAs, translation factors, and the ribosome. Finally, future directions and enabling technological advances for the field are discussed.
Collapse
Affiliation(s)
- Michael J Hammerling
- Department of Chemical and Biological Engineering, Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Antje Krüger
- Department of Chemical and Biological Engineering, Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Center for Synthetic Biology, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
| |
Collapse
|
81
|
Liu Q, Zhang H, Huang X. Anti-CRISPR proteins targeting the CRISPR-Cas system enrich the toolkit for genetic engineering. FEBS J 2020; 287:626-644. [PMID: 31730297 DOI: 10.1111/febs.15139] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 10/08/2019] [Accepted: 11/12/2019] [Indexed: 12/18/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas adaptive immune defense systems, which are widely distributed in bacteria and Archaea, can provide sequence-specific protection against foreign DNA or RNA in some cases. However, the evolution of defense systems in bacterial hosts did not lead to the elimination of phages, and some phages carry anti-CRISPR genes that encode products that bind to the components mediating the defense mechanism and thus antagonize CRISPR-Cas immune systems of bacteria. Given the extensive application of CRISPR-Cas9 technologies in gene editing, in this review, we focus on the anti-CRISPR proteins (Acrs) that inhibit CRISPR-Cas systems for gene editing. We describe the discovery of Acrs in immune systems involving type I, II, and V CRISPR-Cas immunity, discuss the potential function of Acrs in inactivating type II and V CRISPR-Cas systems for gene editing and gene modulation, and provide an outlook on the development of important biotechnology tools for genetic engineering using Acrs.
Collapse
Affiliation(s)
- Qiong Liu
- Department of Medical Microbiology, School of Medicine, Nanchang University, China
| | - Hongxia Zhang
- Department of Medical Microbiology, School of Medicine, Nanchang University, China
| | - Xiaotian Huang
- Department of Medical Microbiology, School of Medicine, Nanchang University, China
- Key Laboratory of Tumor Pathogenesis and Molecular Pathology, School of Medicine, Nanchang University, China
| |
Collapse
|
82
|
Ayoubi-Joshaghani MH, Dianat-Moghadam H, Seidi K, Jahanban-Esfahalan A, Zare P, Jahanban-Esfahlan R. Cell-free protein synthesis: The transition from batch reactions to minimal cells and microfluidic devices. Biotechnol Bioeng 2020; 117:1204-1229. [PMID: 31840797 DOI: 10.1002/bit.27248] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 11/23/2019] [Accepted: 12/09/2019] [Indexed: 12/13/2022]
Abstract
Thanks to the synthetic biology, the laborious and restrictive procedure for producing a target protein in living microorganisms by biotechnological approaches can now experience a robust, pliant yet efficient alternative. The new system combined with lab-on-chip microfluidic devices and nanotechnology offers a tremendous potential envisioning novel cell-free formats such as DNA brushes, hydrogels, vesicular particles, droplets, as well as solid surfaces. Acting as robust microreactors/microcompartments/minimal cells, the new platforms can be tuned to perform various tasks in a parallel and integrated manner encompassing gene expression, protein synthesis, purification, detection, and finally enabling cell-cell signaling to bring a collective cell behavior, such as directing differentiation process, characteristics of higher order entities, and beyond. In this review, we issue an update on recent cell-free protein synthesis (CFPS) formats. Furthermore, the latest advances and applications of CFPS for synthetic biology and biotechnology are highlighted. In the end, contemporary challenges and future opportunities of CFPS systems are discussed.
Collapse
Affiliation(s)
| | | | - Khaled Seidi
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | | | - Peyman Zare
- Faculty of Medicine, Cardinal Stefan Wyszyński University in Warsaw, Warsaw, Poland
| | - Rana Jahanban-Esfahlan
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran.,Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran
| |
Collapse
|
83
|
DeNies MS, Liu AP, Schnell S. Are the biomedical sciences ready for synthetic biology? Biomol Concepts 2020; 11:23-31. [PMID: 31982863 DOI: 10.1515/bmc-2020-0003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 01/02/2020] [Indexed: 11/15/2022] Open
Abstract
The ability to construct a functional system from its individual components is foundational to understanding how it works. Synthetic biology is a broad field that draws from principles of engineering and computer science to create new biological systems or parts with novel function. While this has drawn well-deserved acclaim within the biotechnology community, application of synthetic biology methodologies to study biological systems has potential to fundamentally change how biomedical research is conducted by providing researchers with improved experimental control. While the concepts behind synthetic biology are not new, we present evidence supporting why the current research environment is conducive for integration of synthetic biology approaches within biomedical research. In this perspective we explore the idea of synthetic biology as a discovery science research tool and provide examples of both top-down and bottom-up approaches that have already been used to answer important physiology questions at both the organismal and molecular level.
Collapse
Affiliation(s)
- Maxwell S DeNies
- Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Allen P Liu
- Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA.,Department of Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Santiago Schnell
- Cellular and Molecular Biology Graduate Program, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA.,Department of Computational Medicine & Bioinformatics, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|
84
|
Silverman AD, Karim AS, Jewett MC. Cell-free gene expression: an expanded repertoire of applications. Nat Rev Genet 2019; 21:151-170. [DOI: 10.1038/s41576-019-0186-3] [Citation(s) in RCA: 246] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2019] [Indexed: 12/24/2022]
|
85
|
Lee J, Mou H, Ibraheim R, Liang SQ, Liu P, Xue W, Sontheimer EJ. Tissue-restricted genome editing in vivo specified by microRNA-repressible anti-CRISPR proteins. RNA (NEW YORK, N.Y.) 2019; 25:1421-1431. [PMID: 31439808 PMCID: PMC6795140 DOI: 10.1261/rna.071704.119] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 08/09/2019] [Indexed: 05/20/2023]
Abstract
CRISPR-Cas systems are bacterial adaptive immune pathways that have revolutionized biotechnology and biomedical applications. Despite the potential for human therapeutic development, there are many hurdles that must be overcome before its use in clinical settings. Some clinical safety concerns arise from editing activity in unintended cell types or tissues upon in vivo delivery (e.g., by adeno-associated virus (AAV) vectors). Although tissue-specific promoters and serotypes with tissue tropisms can be used, suitably compact promoters are not always available for desired cell types, and AAV tissue tropism specificities are not absolute. To reinforce tissue-specific editing, we exploited anti-CRISPR proteins (Acrs) that have evolved as natural countermeasures against CRISPR immunity. To inhibit Cas9 in all ancillary tissues without compromising editing in the target tissue, we established a flexible platform in which an Acr transgene is repressed by endogenous, tissue-specific microRNAs (miRNAs). We demonstrate that miRNAs regulate the expression of an Acr transgene bearing miRNA-binding sites in its 3'-UTR and control subsequent genome editing outcomes in a cell-type specific manner. We also show that the strategy is applicable to multiple Cas9 orthologs and their respective anti-CRISPRs. Furthermore, we validate this approach in vivo by demonstrating that AAV9 delivery of Nme2Cas9, along with an AcrIIC3 Nme construct that is targeted for repression by liver-specific miR-122, allows editing in the liver while repressing editing in an unintended tissue (heart muscle) in adult mice. This strategy provides safeguards against off-tissue genome editing by confining Cas9 activity to selected cell types.
Collapse
Affiliation(s)
- Jooyoung Lee
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Haiwei Mou
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Raed Ibraheim
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Shun-Qing Liang
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Pengpeng Liu
- Program in Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Wen Xue
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| | - Erik J Sontheimer
- RNA Therapeutics Institute, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
| |
Collapse
|
86
|
Kent R, Dixon N. Contemporary Tools for Regulating Gene Expression in Bacteria. Trends Biotechnol 2019; 38:316-333. [PMID: 31679824 DOI: 10.1016/j.tibtech.2019.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Revised: 09/16/2019] [Accepted: 09/17/2019] [Indexed: 12/14/2022]
Abstract
Insights from novel mechanistic paradigms in gene expression control have led to the development of new gene expression systems for bioproduction, control, and sensing applications. Coupled with a greater understanding of synthetic burden and modern creative biodesign approaches, contemporary bacterial gene expression tools and systems are emerging that permit fine-tuning of expression, enabling greater predictability and maximisation of specific productivity, while minimising deleterious effects upon cell viability. These advances have been achieved by using a plethora of regulatory tools, operating at all levels of the so-called 'central dogma' of molecular biology. In this review, we discuss these gene regulation tools in the context of their design, prototyping, integration into expression systems, and biotechnological application.
Collapse
Affiliation(s)
- Ross Kent
- Manchester Institute of Biotechnology and School of Chemistry, University of Manchester, Manchester, UK
| | - Neil Dixon
- Manchester Institute of Biotechnology and School of Chemistry, University of Manchester, Manchester, UK.
| |
Collapse
|
87
|
Pseudomonas putida in the quest of programmable chemistry. Curr Opin Biotechnol 2019; 59:111-121. [DOI: 10.1016/j.copbio.2019.03.012] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 02/15/2019] [Accepted: 03/12/2019] [Indexed: 11/19/2022]
|
88
|
Lehr FX, Hanst M, Vogel M, Kremer J, Göringer HU, Suess B, Koeppl H. Cell-Free Prototyping of AND-Logic Gates Based on Heterogeneous RNA Activators. ACS Synth Biol 2019; 8:2163-2173. [PMID: 31393707 DOI: 10.1021/acssynbio.9b00238] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RNA-based devices controlling gene expression bear great promise for synthetic biology, as they offer many advantages such as short response times and light metabolic burden compared to protein-circuits. However, little work has been done regarding their integration to multilevel regulated circuits. In this work, we combined a variety of small transcriptional activator RNAs (STARs) and toehold switches to build highly effective AND-gates. To characterize the components and their dynamic range, we used an Escherichia coli (E. coli) cell-free transcription-translation (TX-TL) system dispensed via nanoliter droplets. We analyzed a prototype gate in vitro as well as in silico, employing parametrized ordinary differential equations (ODEs), for which parameters were inferred via parallel tempering, a Markov chain Monte Carlo (MCMC) method. On the basis of this analysis, we created nine additional AND-gates and tested them in vitro. The functionality of the gates was found to be highly dependent on the concentration of the activating RNA for either the STAR or the toehold switch. All gates were successfully implemented in vivo, offering a dynamic range comparable to the level of protein circuits. This study shows the potential of a rapid prototyping approach for RNA circuit design, using cell-free systems in combination with a model prediction.
Collapse
Affiliation(s)
- François-Xavier Lehr
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Maleen Hanst
- Department of Electrical Engineering, Technische Universität Darmstadt, 64283 Darmstadt, Germany
| | - Marc Vogel
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Jennifer Kremer
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - H. Ulrich Göringer
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Beatrix Suess
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - Heinz Koeppl
- Department of Biology, Technische Universität Darmstadt, 64287 Darmstadt, Germany
- Department of Electrical Engineering, Technische Universität Darmstadt, 64283 Darmstadt, Germany
| |
Collapse
|
89
|
Cole SD, Beabout K, Turner KB, Smith ZK, Funk VL, Harbaugh SV, Liem AT, Roth PA, Geier BA, Emanuel PA, Walper SA, Chávez JL, Lux MW. Quantification of Interlaboratory Cell-Free Protein Synthesis Variability. ACS Synth Biol 2019; 8:2080-2091. [PMID: 31386355 DOI: 10.1021/acssynbio.9b00178] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cell-free protein synthesis (CFPS) platforms, once primarily a research tool to produce difficult to express proteins, are increasingly being pursued by the synthetic biology community for applications including biomanufacturing, rapid screening systems, and field-ready sensors. While consistency within individual studies is apparent in the literature, challenges with reproducing results between laboratories, or even between individuals within a laboratory, are discussed openly by practitioners. As the field continues to grow and move toward applications, a quantitative understanding of expected variability for CFPS and the relative contribution of underlying sources will become increasingly important. Here we offer the first quantitative assessment of interlaboratory variability in CFPS. Three laboratories implemented a single CFPS protocol and performed a series of exchanges, both of material and personnel, designed to quantify relative contributions to variability associated with the site, operator, cell extract preparation, and supplemental reagent preparation. We found that materials prepared at each laboratory, exchanged pairwise, and tested at each site resulted in 40.3% coefficient of variation compared to 7.64% for a single operator across days using a single set of materials. Reagent preparations contributed significantly to observed variability; extract preparations, however, surprisingly did not explain any of the observed variability, even when prepared in different laboratories by different operators. Subsequent exchanges showed that both the site and the operator each contributed to observed interlaboratory variability. In addition to providing the first quantitative assessment of interlaboratory variability in CFPS, these results establish a baseline for individual operator variability across days that can be used as an initial benchmark for community-driven standardization efforts. We anticipate that our results will narrow future avenues of investigation to develop best practices that will ultimately drive down interlaboratory variability, accelerating research progress and informing the suitability of CFPS for real-world applications.
Collapse
Affiliation(s)
- Stephanie D. Cole
- US Army Combat Capabilities Development Command Chemical Biological Center. 8198 Blackhawk Road, APG, Maryland 21010, United States
- Excet, Inc., 6225 Brandon Avenue #360, Springfield, Virginia 22150, United States
| | - Kathryn Beabout
- UES, Inc., Dayton, Ohio 45432, United States
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Kendrick B. Turner
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Zachary K. Smith
- UES, Inc., Dayton, Ohio 45432, United States
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Vanessa L. Funk
- US Army Combat Capabilities Development Command Chemical Biological Center. 8198 Blackhawk Road, APG, Maryland 21010, United States
| | - Svetlana V. Harbaugh
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Alvin T. Liem
- DCS Corporation, 100 Walter Ward Blvd, Suite 100, Abingdon, Maryland 21009, United States
| | - Pierce A. Roth
- DCS Corporation, 100 Walter Ward Blvd, Suite 100, Abingdon, Maryland 21009, United States
| | - Brian A. Geier
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Peter A. Emanuel
- US Army Combat Capabilities Development Command Chemical Biological Center. 8198 Blackhawk Road, APG, Maryland 21010, United States
| | - Scott A. Walper
- Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, D.C. 20375, United States
| | - Jorge L. Chávez
- Air Force Research Laboratory, 711th Human Performance Wing, Wright-Patterson Air Force Base, Ohio 45433, United States
| | - Matthew W. Lux
- US Army Combat Capabilities Development Command Chemical Biological Center. 8198 Blackhawk Road, APG, Maryland 21010, United States
| |
Collapse
|
90
|
Forsberg KJ, Bhatt IV, Schmidtke DT, Javanmardi K, Dillard KE, Stoddard BL, Finkelstein IJ, Kaiser BK, Malik HS. Functional metagenomics-guided discovery of potent Cas9 inhibitors in the human microbiome. eLife 2019; 8:e46540. [PMID: 31502535 PMCID: PMC6739867 DOI: 10.7554/elife.46540] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2019] [Accepted: 08/09/2019] [Indexed: 12/12/2022] Open
Abstract
CRISPR-Cas systems protect bacteria and archaea from phages and other mobile genetic elements, which use small anti-CRISPR (Acr) proteins to overcome CRISPR-Cas immunity. Because Acrs are challenging to identify, their natural diversity and impact on microbial ecosystems are underappreciated. To overcome this discovery bottleneck, we developed a high-throughput functional selection to isolate ten DNA fragments from human oral and fecal metagenomes that inhibit Streptococcus pyogenes Cas9 (SpyCas9) in Escherichia coli. The most potent Acr from this set, AcrIIA11, was recovered from a Lachnospiraceae phage. We found that AcrIIA11 inhibits SpyCas9 in bacteria and in human cells. AcrIIA11 homologs are distributed across diverse bacteria; many distantly-related homologs inhibit both SpyCas9 and a divergent Cas9 from Treponema denticola. We find that AcrIIA11 antagonizes SpyCas9 using a different mechanism than other previously characterized Type II-A Acrs. Our study highlights the power of functional selection to uncover widespread Cas9 inhibitors within diverse microbiomes.
Collapse
Affiliation(s)
- Kevin J Forsberg
- Division of Basic SciencesFred Hutchinson Cancer Research CenterSeattleUnited States
| | - Ishan V Bhatt
- Division of Basic SciencesFred Hutchinson Cancer Research CenterSeattleUnited States
| | - Danica T Schmidtke
- Division of Basic SciencesFred Hutchinson Cancer Research CenterSeattleUnited States
| | - Kamyab Javanmardi
- Department of Molecular Biosciences and Institute of Cellular and Molecular BiologyUniversity of Texas at AustinAustinUnited States
| | - Kaylee E Dillard
- Department of Molecular Biosciences and Institute of Cellular and Molecular BiologyUniversity of Texas at AustinAustinUnited States
| | - Barry L Stoddard
- Division of Basic SciencesFred Hutchinson Cancer Research CenterSeattleUnited States
| | - Ilya J Finkelstein
- Department of Molecular Biosciences and Institute of Cellular and Molecular BiologyUniversity of Texas at AustinAustinUnited States
- Center for Systems Biology and Synthetic BiologyUniversity of Texas at AustinAustinUnited States
| | - Brett K Kaiser
- Division of Basic SciencesFred Hutchinson Cancer Research CenterSeattleUnited States
- Department of BiologySeattle UniversitySeattleUnited States
| | - Harmit S Malik
- Division of Basic SciencesFred Hutchinson Cancer Research CenterSeattleUnited States
- Howard Hughes Medical Institute, Fred Hutchinson Cancer Research CenterSeattleUnited States
| |
Collapse
|
91
|
Pandi A, Grigoras I, Borkowski O, Faulon JL. Optimizing Cell-Free Biosensors to Monitor Enzymatic Production. ACS Synth Biol 2019; 8:1952-1957. [PMID: 31335131 DOI: 10.1021/acssynbio.9b00160] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cell-free systems are promising platforms for rapid and high-throughput prototyping of biological parts in metabolic engineering and synthetic biology. One main limitation of cell-free system applications is the low fold repression of transcriptional repressors. Hence, prokaryotic biosensor development, which mostly relies on repressors, is limited. In this study, we demonstrate how to improve these biosensors in cell-free systems by applying a transcription factor (TF)-doped extract, a preincubation strategy with the TF plasmid, or reinitiation of the cell-free reaction (two-step cell-free reaction). We use the optimized biosensor to sense the enzymatic production of a rare sugar, D-psicose. This work provides a methodology to optimize repressor-based systems in cell-free to further increase the potential of cell-free systems for bioproduction.
Collapse
Affiliation(s)
- Amir Pandi
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas 78352, France
| | - Ioana Grigoras
- iSSB Laboratory, Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, 91057 Evry, France
| | - Olivier Borkowski
- iSSB Laboratory, Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, 91057 Evry, France
| | - Jean-Loup Faulon
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas 78352, France
- iSSB Laboratory, Génomique Métabolique, Genoscope, Institut François Jacob, CEA, CNRS, Université Evry, Université Paris-Saclay, 91057 Evry, France
- SYNBIOCHEM Center, School of Chemistry, University of Manchester, Manchester M13 9PL, U.K
| |
Collapse
|
92
|
Sun M, Li Z, Wang S, Maryu G, Yang Q. Building Dynamic Cellular Machineries in Droplet-Based Artificial Cells with Single-Droplet Tracking and Analysis. Anal Chem 2019; 91:9813-9818. [PMID: 31284720 PMCID: PMC7260773 DOI: 10.1021/acs.analchem.9b01481] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Although the application of droplet microfluidics has grown exponentially in chemistry and biology over the past decades, robust universal platforms for the routine generation and comprehensive analysis of droplet-based artificial cells are still rare. Here we report using microfluidic droplets to reproduce a variety of types of cellular machinery in in vitro artificial cells. In combination with a unique image-based analysis method, the system enables full automation in tracking single droplets with high accuracy, high throughput, and high sensitivity. These powerful performances allow broad applicability evident in three representative droplet-based analytical prototypes that we develop for (i) droplet digital detection, (ii) in vitro transcription and translation reactions, and (iii) spatiotemporal dynamics of cell-cycle oscillations. The capacities of this platform to generate, incubate, track, and analyze individual microdroplets via real-time, long-term imaging unleash its great potential in accelerating cell-free synthetic biology. Moreover, the wide scope covering from digital to analog to morphological detections makes this droplet analysis technique adaptable for many other divergent types of droplet-based chemical and biological assays.
Collapse
Affiliation(s)
- Meng Sun
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Zhengda Li
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Shiyuan Wang
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Gembu Maryu
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| | - Qiong Yang
- Department of Biophysics, University of Michigan, 930 N. University Avenue, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
93
|
Yim SS, Johns NI, Park J, Gomes ALC, McBee RM, Richardson M, Ronda C, Chen SP, Garenne D, Noireaux V, Wang HH. Multiplex transcriptional characterizations across diverse bacterial species using cell-free systems. Mol Syst Biol 2019; 15:e8875. [PMID: 31464371 PMCID: PMC6692573 DOI: 10.15252/msb.20198875] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 07/01/2019] [Accepted: 07/03/2019] [Indexed: 12/14/2022] Open
Abstract
Cell-free expression systems enable rapid prototyping of genetic programs in vitro. However, current throughput of cell-free measurements is limited by the use of channel-limited fluorescent readouts. Here, we describe DNA Regulatory element Analysis by cell-Free Transcription and Sequencing (DRAFTS), a rapid and robust in vitro approach for multiplexed measurement of transcriptional activities from thousands of regulatory sequences in a single reaction. We employ this method in active cell lysates developed from ten diverse bacterial species. Interspecies analysis of transcriptional profiles from > 1,000 diverse regulatory sequences reveals functional differences in promoter activity that can be quantitatively modeled, providing a rich resource for tuning gene expression in diverse bacterial species. Finally, we examine the transcriptional capacities of dual-species hybrid lysates that can simultaneously harness gene expression properties of multiple organisms. We expect that this cell-free multiplex transcriptional measurement approach will improve genetic part prototyping in new bacterial chassis for synthetic biology.
Collapse
Affiliation(s)
- Sung Sun Yim
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
| | - Nathan I Johns
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
- Present address:
Department of BioengineeringStanford UniversityStanfordCAUSA
| | - Jimin Park
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
| | - Antonio LC Gomes
- Department of ImmunologyMemorial Sloan Kettering Cancer CenterNew YorkNYUSA
| | - Ross M McBee
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Department of Biological SciencesColumbia UniversityNew YorkNYUSA
| | - Miles Richardson
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
| | - Carlotta Ronda
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
| | - Sway P Chen
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Integrated Program in Cellular, Molecular, and Biomedical StudiesColumbia UniversityNew YorkNYUSA
| | - David Garenne
- School of Physics and AstronomyUniversity of MinnesotaMinneapolisMNUSA
| | - Vincent Noireaux
- School of Physics and AstronomyUniversity of MinnesotaMinneapolisMNUSA
| | - Harris H Wang
- Department of Systems BiologyColumbia UniversityNew YorkNYUSA
- Department of Pathology and Cell BiologyColumbia UniversityNew YorkNYUSA
| |
Collapse
|
94
|
Garenne D, Noireaux V. Cell-free transcription–translation: engineering biology from the nanometer to the millimeter scale. Curr Opin Biotechnol 2019; 58:19-27. [DOI: 10.1016/j.copbio.2018.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 10/14/2018] [Indexed: 01/01/2023]
|
95
|
Modular one-pot assembly of CRISPR arrays enables library generation and reveals factors influencing crRNA biogenesis. Nat Commun 2019; 10:2948. [PMID: 31270316 PMCID: PMC6610086 DOI: 10.1038/s41467-019-10747-3] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/22/2019] [Indexed: 12/19/2022] Open
Abstract
CRISPR-Cas systems inherently multiplex through CRISPR arrays—whether to defend against different invaders or mediate multi-target editing, regulation, imaging, or sensing. However, arrays remain difficult to generate due to their reoccurring repeat sequences. Here, we report a modular, one-pot scheme called CRATES to construct CRISPR arrays and array libraries. CRATES allows assembly of repeat-spacer subunits using defined assembly junctions within the trimmed portion of spacers. Using CRATES, we construct arrays for the single-effector nucleases Cas9, Cas12a, and Cas13a that mediated multiplexed DNA/RNA cleavage and gene regulation in cell-free systems, bacteria, and yeast. CRATES further allows the one-pot construction of array libraries and composite arrays utilized by multiple Cas nucleases. Finally, array characterization reveals processing of extraneous CRISPR RNAs from Cas12a terminal repeats and sequence- and context-dependent loss of RNA-directed nuclease activity via global RNA structure formation. CRATES thus can facilitate diverse multiplexing applications and help identify factors impacting crRNA biogenesis. CRISPR array generation is difficult due to reoccurring repeat sequences. Here the authors present CRATES—a modular, one-pot assembly method—and demonstrate the creation of arrays for Cas9, Cas12a and Cas13a for cell-free, bacterial, yeast and mammalian systems.
Collapse
|
96
|
Barriers to genome editing with CRISPR in bacteria. J Ind Microbiol Biotechnol 2019; 46:1327-1341. [PMID: 31165970 DOI: 10.1007/s10295-019-02195-1] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 05/23/2019] [Indexed: 02/08/2023]
Abstract
Genome editing is essential for probing genotype-phenotype relationships and for enhancing chemical production and phenotypic robustness in industrial bacteria. Currently, the most popular tools for genome editing couple recombineering with DNA cleavage by the CRISPR nuclease Cas9 from Streptococcus pyogenes. Although successful in some model strains, CRISPR-based genome editing has been slow to extend to the multitude of industrially relevant bacteria. In this review, we analyze existing barriers to implementing CRISPR-based editing across diverse bacterial species. We first compare the efficacy of current CRISPR-based editing strategies. Next, we discuss alternatives when the S. pyogenes Cas9 does not yield colonies. Finally, we describe different ways bacteria can evade editing and how elucidating these failure modes can improve CRISPR-based genome editing across strains. Together, this review highlights existing obstacles to CRISPR-based editing in bacteria and offers guidelines to help achieve and enhance editing in a wider range of bacterial species, including non-model strains.
Collapse
|
97
|
Zhang F, Song G, Tian Y. Anti-CRISPRs: The natural inhibitors for CRISPR-Cas systems. Animal Model Exp Med 2019; 2:69-75. [PMID: 31392299 PMCID: PMC6600654 DOI: 10.1002/ame2.12069] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Revised: 04/29/2019] [Accepted: 05/06/2019] [Indexed: 12/22/2022] Open
Abstract
CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR associated protein) systems serve as the adaptive immune system by which prokaryotes defend themselves against phages. It has also been developed into a series of powerful gene-editing tools. As the natural inhibitors of CRISPR-Cas systems, anti-CRISPRs (Acrs) can be used as the "off-switch" for CRISPR-Cas systems to limit the off-target effects caused by Cas9. Since the discovery of CRISPR-Cas systems, much research has focused on the identification, mechanisms and applications of Acrs. In light of the rapid development and scientific significance of this field, this review summarizes the history and research status of Acrs, and considers future applications.
Collapse
Affiliation(s)
- Fei Zhang
- CAS Key Laboratory of RNA BiologyInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Guoxu Song
- CAS Key Laboratory of RNA BiologyInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
| | - Yong Tian
- CAS Key Laboratory of RNA BiologyInstitute of Biophysics, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| |
Collapse
|
98
|
Garenne D, Beisel CL, Noireaux V. Characterization of the all-E. coli transcription-translation system myTXTL by mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2019; 33:1036-1048. [PMID: 30900355 DOI: 10.1002/rcm.8438] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 03/05/2019] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
RATIONALE Cell-free transcription-translation (TXTL) is becoming a popular technology to prototype and engineer biological systems outside living organisms. TXTL relies commonly on a cytoplasmic extract that provides the molecular components necessary to recapitulate gene expression in vitro, where most of the available systems are derived from E. coli. The proteinic and enzymatic composition of lysates, however, is typically unknown. In this work, we analyzed by mass spectrometry the molecular constituents of the all-E. coli TXTL platform myTXTL prepared from the E. coli strain BL21 Rosetta2. METHODS Standard TXTL reactions were assembled and executed for 10-12 hours at 29°C. In addition to a no-DNA control, four DNA programs were executed in separate reactions to synthesize the reporter protein deGFP as well as the phages MS2, phix174 and T7. The reactions were treated according to standard procedures (trypsin treatment, cleaning) before performing liquid chromatography/mass spectrometry (LC/MS). Data analysis was performed using Sequest and protein identification using Scaffold. RESULTS A total of 500-800 proteins were identified by LC/MS in the blank reactions. We organized the most abundant protein sets into several categories pertaining, in particular, to transcription, translation and ATP regeneration. The synthesis of deGFP was easily measured. The major structural proteins that compose the three phages MS2, phix174 and T7 were also identified. CONCLUSIONS Mass spectrometry is a practical tool to characterize biochemical solutions as complex as a cell-free TXTL reaction and to determine the presence of synthesized proteins. The data presented demonstrate that the composition of TXTL based on lysates can be used to validate some underlying molecular mechanisms implicated in cell-free protein synthesis. The composition of the lysate shows significant differences with respect to similar studies on other E. coli strains.
Collapse
Affiliation(s)
- David Garenne
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN, 55455, USA
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Center for Infection (HZI) Research, 97080, Würzburg, Germany
- Medical Faculty, University of Würzburg, Würzburg, Germany
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN, 55455, USA
| |
Collapse
|
99
|
Jeong D, Klocke M, Agarwal S, Kim J, Choi S, Franco E, Kim J. Cell-Free Synthetic Biology Platform for Engineering Synthetic Biological Circuits and Systems. Methods Protoc 2019; 2:E39. [PMID: 31164618 PMCID: PMC6632179 DOI: 10.3390/mps2020039] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/12/2019] [Accepted: 05/08/2019] [Indexed: 01/07/2023] Open
Abstract
Synthetic biology brings engineering disciplines to create novel biological systems for biomedical and technological applications. The substantial growth of the synthetic biology field in the past decade is poised to transform biotechnology and medicine. To streamline design processes and facilitate debugging of complex synthetic circuits, cell-free synthetic biology approaches has reached broad research communities both in academia and industry. By recapitulating gene expression systems in vitro, cell-free expression systems offer flexibility to explore beyond the confines of living cells and allow networking of synthetic and natural systems. Here, we review the capabilities of the current cell-free platforms, focusing on nucleic acid-based molecular programs and circuit construction. We survey the recent developments including cell-free transcription-translation platforms, DNA nanostructures and circuits, and novel classes of riboregulators. The links to mathematical models and the prospects of cell-free synthetic biology platforms will also be discussed.
Collapse
Affiliation(s)
- Dohyun Jeong
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Pohang, Gyeongbuk 37673, Korea.
| | - Melissa Klocke
- Department of Mechanical Engineering, University of California at Riverside, 900 University Ave, Riverside, CA 92521, USA.
| | - Siddharth Agarwal
- Department of Mechanical Engineering, University of California at Riverside, 900 University Ave, Riverside, CA 92521, USA.
| | - Jeongwon Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Pohang, Gyeongbuk 37673, Korea.
| | - Seungdo Choi
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Pohang, Gyeongbuk 37673, Korea.
| | - Elisa Franco
- Department of Mechanical and Aerospace Engineering, University of California at Los Angeles, 420 Westwood Plaza, Los Angeles, CA 90095, USA.
| | - Jongmin Kim
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Pohang, Gyeongbuk 37673, Korea.
| |
Collapse
|
100
|
Liu P, Luk K, Shin M, Idrizi F, Kwok S, Roscoe B, Mintzer E, Suresh S, Morrison K, Frazão JB, Bolukbasi MF, Ponnienselvan K, Luban J, Zhu LJ, Lawson ND, Wolfe SA. Enhanced Cas12a editing in mammalian cells and zebrafish. Nucleic Acids Res 2019; 47:4169-4180. [PMID: 30892626 PMCID: PMC6486634 DOI: 10.1093/nar/gkz184] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/04/2019] [Accepted: 03/15/2019] [Indexed: 11/29/2022] Open
Abstract
Type V CRISPR-Cas12a systems provide an alternate nuclease platform to Cas9, with potential advantages for specific genome editing applications. Here we describe improvements to the Cas12a system that facilitate efficient targeted mutagenesis in mammalian cells and zebrafish embryos. We show that engineered variants of Cas12a with two different nuclear localization sequences (NLS) on the C terminus provide increased editing efficiency in mammalian cells. Additionally, we find that pre-crRNAs comprising a full-length direct repeat (full-DR-crRNA) sequence with specific stem-loop G-C base substitutions exhibit increased editing efficiencies compared with the standard mature crRNA framework. Finally, we demonstrate in zebrafish embryos that the improved LbCas12a and FnoCas12a nucleases in combination with these modified crRNAs display high mutagenesis efficiencies and low toxicity when delivered as ribonucleoprotein complexes at high concentration. Together, these results define a set of enhanced Cas12a components with broad utility in vertebrate systems.
Collapse
Affiliation(s)
- Pengpeng Liu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Kevin Luk
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Masahiro Shin
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Feston Idrizi
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Samantha Kwok
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Benjamin Roscoe
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Esther Mintzer
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Sneha Suresh
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Kyle Morrison
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA, USA
| | - Josias B Frazão
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Mehmet Fatih Bolukbasi
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Karthikeyan Ponnienselvan
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jeremy Luban
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA
| | - Lihua Julie Zhu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA, USA
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Nathan D Lawson
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA
| | - Scot A Wolfe
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Medical School, Worcester, Massachusetts, USA
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
- Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, USA
| |
Collapse
|