1
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Clark L, Voigt CA, Jewett MC. Establishing a High-Yield Chloroplast Cell-Free System for Prototyping Genetic Parts. ACS Synth Biol 2024; 13:2402-2411. [PMID: 39023433 DOI: 10.1021/acssynbio.4c00111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2024]
Abstract
Plastid engineering offers the potential to carry multigene traits in plants; however, it requires reliable genetic parts to balance expression. The difficulty of chloroplast transformation and slow plant growth makes it challenging to build plants just to characterize genetic parts. To address these limitations, we developed a high-yield cell-free system from Nicotiana tabacum chloroplast extracts for prototyping genetic parts. Our cell-free system uses combined transcription and translation driven by T7 RNA polymerase and works with plasmid or linear template DNA. To develop our system, we optimized lysis, extract preparation procedures (e.g., runoff reaction, centrifugation, and dialysis), and the physiochemical reaction conditions. Our cell-free system can synthesize 34 ± 1 μg/mL luciferase in batch reactions and 60 ± 4 μg/mL in semicontinuous reactions. We apply our batch reaction system to test a library of 103 ribosome binding site (RBS) variants and rank them based on cell-free gene expression. We observe a 1300-fold dynamic range of luciferase expression when normalized by maximum mRNA expression, as assessed by the malachite green aptamer. We also find that the observed normalized gene expression in chloroplast extracts and the predictions made by the RBS Calculator are correlated. We anticipate that chloroplast cell-free systems will increase the speed and reliability of building genetic systems in plant chloroplasts for diverse applications.
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Affiliation(s)
- Lauren Clark
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Christopher A Voigt
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
- Robert H. Lurie Comprehensive Cancer Center, Chicago, Illinois 60611, United States
- Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, United States
- Department of Bioengineering, Stanford University, Stanford, California 94305, United States
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2
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Roberts A, Spang D, Sanozky-Dawes R, Nethery MA, Barrangou R. Characterization of Ligilactobacillus salivarius CRISPR-Cas systems. mSphere 2024; 9:e0017124. [PMID: 38990000 PMCID: PMC11288051 DOI: 10.1128/msphere.00171-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 06/11/2024] [Indexed: 07/12/2024] Open
Abstract
Ligilactobacillus is a diverse genus among lactobacilli with phenotypes that reflect adaptation to various hosts. CRISPR-Cas systems are highly prevalent within lactobacilli, and Ligilactobacillus salivarius, the most abundant species of Ligilactobacillus, possesses both DNA- and RNA-targeting CRISPR-Cas systems. In this study, we explore the presence and functional properties of I-B, I-C, I-E, II-A, and III-A CRISPR-Cas systems in over 500 Ligilactobacillus genomes, emphasizing systems found in L. salivarius. We examined the I-E, II-A, and III-A CRISPR-Cas systems of two L. salivarius strains and observed occurrences of split cas genes and differences in CRISPR RNA maturation in native hosts. This prompted testing of the single Cas9 and multiprotein Cascade and Csm CRISPR-Cas effector complexes in a cell-free context to demonstrate the functionality of these systems. We also predicted self-targeting spacers within L. salivarius CRISPR-Cas systems and found that nearly a third of L. salivarius genomes possess unique self-targeting spacers that generally target elements other than prophages. With these two L. salivarius strains, we performed prophage induction coupled with RNA sequencing and discovered that the prophages residing within these strains are inducible and likely active elements, despite targeting by CRISPR-Cas systems. These findings deepen our comprehension of CRISPR-Cas systems in L. salivarius, further elucidating their relationship with associated prophages and providing a functional basis for the repurposing of these Cas effectors for bacterial manipulation. IMPORTANCE Ligilactobacillus salivarius is a diverse bacterial species widely used in the food and dietary supplement industries. In this study, we investigate the occurrence and diversity of their adaptive immune systems, CRISPR-Cas, in over 500 genomes. We establish their function and provide insights into their role in the interplay between the bacterial host and the predatory phages that infect them. Such findings expand our knowledge about these important CRISPR-Cas immune systems widespread across the bacterial tree of life and also provide a technical basis for the repurposing of these molecular machines for the development of molecular biology tools and the manipulation and engineering of bacteria and other life forms.
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Affiliation(s)
- Avery Roberts
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Daniel Spang
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | - Rosemary Sanozky-Dawes
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA
| | | | - Rodolphe Barrangou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, North Carolina, USA
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3
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Jiao C, Peeck NL, Yu J, Ghaem Maghami M, Kono S, Collias D, Martinez Diaz SL, Larose R, Beisel CL. TracrRNA reprogramming enables direct PAM-independent detection of RNA with diverse DNA-targeting Cas12 nucleases. Nat Commun 2024; 15:5909. [PMID: 39003282 PMCID: PMC11246509 DOI: 10.1038/s41467-024-50243-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 07/04/2024] [Indexed: 07/15/2024] Open
Abstract
Many CRISPR-Cas immune systems generate guide (g)RNAs using trans-activating CRISPR RNAs (tracrRNAs). Recent work revealed that Cas9 tracrRNAs could be reprogrammed to convert any RNA-of-interest into a gRNA, linking the RNA's presence to Cas9-mediated cleavage of double-stranded (ds)DNA. Here, we reprogram tracrRNAs from diverse Cas12 nucleases, linking the presence of an RNA-of-interest to dsDNA cleavage and subsequent collateral single-stranded DNA cleavage-all without the RNA necessarily encoding a protospacer-adjacent motif (PAM). After elucidating nuclease-specific design rules, we demonstrate PAM-independent RNA detection with Cas12b, Cas12e, and Cas12f nucleases. Furthermore, rationally truncating the dsDNA target boosts collateral cleavage activity, while the absence of a gRNA reduces background collateral activity and enhances sensitivity. Finally, we apply this platform to detect 16 S rRNA sequences from five different bacterial pathogens using a universal reprogrammed tracrRNA. These findings extend tracrRNA reprogramming to diverse dsDNA-targeting Cas12 nucleases, expanding the flexibility and versatility of CRISPR-based RNA detection.
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Affiliation(s)
- Chunlei Jiao
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Natalia L Peeck
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Jiaqi Yu
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Mohammad Ghaem Maghami
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Sarah Kono
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Daphne Collias
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Sandra L Martinez Diaz
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Rachael Larose
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany.
- Medical Faculty, University of Würzburg, Würzburg, Germany.
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4
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Okamura H, Yao T, Nagatsugi F. Reversible Control of Gene Expression by Guest-Modified Adenosines in a Cell-Free System via Host-Guest Interaction. J Am Chem Soc 2024; 146:18513-18523. [PMID: 38941287 PMCID: PMC11240562 DOI: 10.1021/jacs.4c04262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 06/30/2024]
Abstract
Gene expression technology has become an indispensable tool for elucidating biological processes and developing biotechnology. Cell-free gene expression (CFE) systems offer a fundamental platform for gene expression-based technology, in which the reversible and programmable control of transcription can expand its use in synthetic biology and medicine. This study shows that CFE can be controlled via the host-guest interaction of cucurbit[7]uril (CB[7]) with N6-guest-modified adenosines. These adenosine derivatives were conveniently incorporated into the DNA strand using a post-synthetic approach and formed a selective and stable base pair with complementary thymidine in DNA. Meanwhile, alternate addition of CB[7] and the exchanging guest molecule induced the reversible formation of a duplex structure through the formation and dissociation of a bulky complex on DNA. The kinetics of the reversibility was fine-tuned by changing the size of the modified guest moieties. When incorporated into a specific region of the T7 promoter sequence, the guest-modified adenosines enabled tight and reversible control of in vitro transcription and protein expression in the CFE system. This study marks the first utility of the host-guest interaction for gene expression control in the CFE system, opening new avenues for developing DNA-based technology, particularly for precise gene therapy and DNA nanotechnology.
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Affiliation(s)
- Hidenori Okamura
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Department
of Chemistry, Graduate School of Science, Tohoku University, Miyagi 980-8578, Japan
| | - Takeyuki Yao
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Department
of Chemistry, Graduate School of Science, Tohoku University, Miyagi 980-8578, Japan
| | - Fumi Nagatsugi
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
- Department
of Chemistry, Graduate School of Science, Tohoku University, Miyagi 980-8578, Japan
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5
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Burbano DA, Kiattisewee C, Karanjia AV, Cardiff RAL, Faulkner ID, Sugianto W, Carothers JM. CRISPR Tools for Engineering Prokaryotic Systems: Recent Advances and New Applications. Annu Rev Chem Biomol Eng 2024; 15:389-430. [PMID: 38598861 DOI: 10.1146/annurev-chembioeng-100522-114706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
In the past decades, the broad selection of CRISPR-Cas systems has revolutionized biotechnology by enabling multimodal genetic manipulation in diverse organisms. Rooted in a molecular engineering perspective, we recapitulate the different CRISPR components and how they can be designed for specific genetic engineering applications. We first introduce the repertoire of Cas proteins and tethered effectors used to program new biological functions through gene editing and gene regulation. We review current guide RNA (gRNA) design strategies and computational tools and how CRISPR-based genetic circuits can be constructed through regulated gRNA expression. Then, we present recent advances in CRISPR-based biosensing, bioproduction, and biotherapeutics across in vitro and in vivo prokaryotic systems. Finally, we discuss forthcoming applications in prokaryotic CRISPR technology that will transform synthetic biology principles in the near future.
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Affiliation(s)
- Diego Alba Burbano
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Cholpisit Kiattisewee
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Ava V Karanjia
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Ryan A L Cardiff
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Ian D Faulkner
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - Widianti Sugianto
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
| | - James M Carothers
- Department of Chemical Engineering, University of Washington, Seattle, Washington, USA
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, Washington, USA;
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6
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Leal-Alves C, Deng Z, Kermeci N, Shih SCC. Integrating microfluidics and synthetic biology: advancements and diverse applications across organisms. LAB ON A CHIP 2024; 24:2834-2860. [PMID: 38712893 DOI: 10.1039/d3lc01090b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Synthetic biology is the design and modification of biological systems for specific functions, integrating several disciplines like engineering, genetics, and computer science. The field of synthetic biology is to understand biological processes within host organisms through the manipulation and regulation of their genetic pathways and the addition of biocontrol circuits to enhance their production capabilities. This pursuit serves to address global challenges spanning diverse domains that are difficult to tackle through conventional routes of production. Despite its impact, achieving precise, dynamic, and high-throughput manipulation of biological processes is still challenging. Microfluidics offers a solution to those challenges, enabling controlled fluid handling at the microscale, offering lower reagent consumption, faster analysis of biochemical reactions, automation, and high throughput screening. In this review, we diverge from conventional focus on automating the synthetic biology design-build-test-learn cycle, and instead, focus on microfluidic platforms and their role in advancing synthetic biology through its integration with host organisms - bacterial cells, yeast, fungi, animal cells - and cell-free systems. The review illustrates how microfluidic devices have been instrumental in understanding biological systems by showcasing microfluidics as an essential tool to create synthetic genetic circuits, pathways, and organisms within controlled environments. In conclusion, we show how microfluidics expedite synthetic biology applications across diverse domains including but not limited to personalized medicine, bioenergy, and agriculture.
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Affiliation(s)
- Chiara Leal-Alves
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. W, Montréal, QC, H4B1R6 Canada.
- Department of Electrical and Computer Engineering, Concordia University, 1515 Ste-Catherine St. W, Montréal, QC, H3G1M8 Canada
| | - Zhiyang Deng
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. W, Montréal, QC, H4B1R6 Canada.
- Department of Electrical and Computer Engineering, Concordia University, 1515 Ste-Catherine St. W, Montréal, QC, H3G1M8 Canada
| | - Natalia Kermeci
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. W, Montréal, QC, H4B1R6 Canada.
- Department of Biology, Concordia University, 7141 Sherbrooke St. W, Montréal, QC, H4B1R6 Canada
| | - Steve C C Shih
- Centre for Applied Synthetic Biology, Concordia University, 7141 Sherbrooke St. W, Montréal, QC, H4B1R6 Canada.
- Department of Electrical and Computer Engineering, Concordia University, 1515 Ste-Catherine St. W, Montréal, QC, H3G1M8 Canada
- Department of Biology, Concordia University, 7141 Sherbrooke St. W, Montréal, QC, H4B1R6 Canada
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7
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Jensen RO, Schulz F, Roux S, Klingeman DM, Mitchell WP, Udwary D, Moraïs S, Reynoso V, Winkler J, Nagaraju S, De Tissera S, Shapiro N, Ivanova N, Reddy TBK, Mizrahi I, Utturkar SM, Bayer EA, Woyke T, Mouncey NJ, Jewett MC, Simpson SD, Köpke M, Jones DT, Brown SD. Phylogenomics and genetic analysis of solvent-producing Clostridium species. Sci Data 2024; 11:432. [PMID: 38693191 PMCID: PMC11063209 DOI: 10.1038/s41597-024-03210-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 04/02/2024] [Indexed: 05/03/2024] Open
Abstract
The genus Clostridium is a large and diverse group within the Bacillota (formerly Firmicutes), whose members can encode useful complex traits such as solvent production, gas-fermentation, and lignocellulose breakdown. We describe 270 genome sequences of solventogenic clostridia from a comprehensive industrial strain collection assembled by Professor David Jones that includes 194 C. beijerinckii, 57 C. saccharobutylicum, 4 C. saccharoperbutylacetonicum, 5 C. butyricum, 7 C. acetobutylicum, and 3 C. tetanomorphum genomes. We report methods, analyses and characterization for phylogeny, key attributes, core biosynthetic genes, secondary metabolites, plasmids, prophage/CRISPR diversity, cellulosomes and quorum sensing for the 6 species. The expanded genomic data described here will facilitate engineering of solvent-producing clostridia as well as non-model microorganisms with innately desirable traits. Sequences could be applied in conventional platform biocatalysts such as yeast or Escherichia coli for enhanced chemical production. Recently, gene sequences from this collection were used to engineer Clostridium autoethanogenum, a gas-fermenting autotrophic acetogen, for continuous acetone or isopropanol production, as well as butanol, butanoic acid, hexanol and hexanoic acid production.
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Affiliation(s)
| | - Frederik Schulz
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Simon Roux
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | | | - Daniel Udwary
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Sarah Moraïs
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | | | | | | | | | - Nicole Shapiro
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Natalia Ivanova
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - T B K Reddy
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Itzhak Mizrahi
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
| | - Sagar M Utturkar
- Institute for Cancer Research, Purdue University, West Lafayette, IN, USA
| | - Edward A Bayer
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 84105, Israel
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Tanja Woyke
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- University of California Merced, Life and Environmental Sciences, Merced, CA, USA
| | - Nigel J Mouncey
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Michael C Jewett
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | | | | | - David T Jones
- Department of Microbiology, University of Otago, Dunedin, New Zealand.
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8
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Prezza G, Liao C, Reichardt S, Beisel CL, Westermann AJ. CRISPR-based screening of small RNA modulators of bile susceptibility in Bacteroides thetaiotaomicron. Proc Natl Acad Sci U S A 2024; 121:e2311323121. [PMID: 38294941 PMCID: PMC10861873 DOI: 10.1073/pnas.2311323121] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 12/12/2023] [Indexed: 02/02/2024] Open
Abstract
Microbiota-centric interventions are limited by our incomplete understanding of the gene functions of many of its constituent species. This applies in particular to small RNAs (sRNAs), which are emerging as important regulators in microbiota species yet tend to be missed by traditional functional genomics approaches. Here, we establish CRISPR interference (CRISPRi) in the abundant microbiota member Bacteroides thetaiotaomicron for genome-wide sRNA screens. By assessing the abundance of different protospacer-adjacent motifs, we identify the Prevotella bryantii B14 Cas12a as a suitable nuclease for CRISPR screens in these bacteria and generate an inducible Cas12a expression system. Using a luciferase reporter strain, we infer guide design rules and use this knowledge to assemble a computational pipeline for automated gRNA design. By subjecting the resulting guide library to a phenotypic screen, we uncover the sRNA BatR to increase susceptibility to bile salts through the regulation of genes involved in Bacteroides cell surface structure. Our study lays the groundwork for unlocking the genetic potential of these major human gut mutualists and, more generally, for identifying hidden functions of bacterial sRNAs.
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Affiliation(s)
- Gianluca Prezza
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, WürzburgD-97080, Germany
| | - Chunyu Liao
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, WürzburgD-97080, Germany
| | - Sarah Reichardt
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, WürzburgD-97080, Germany
| | - Chase L. Beisel
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, WürzburgD-97080, Germany
- Medical Faculty, University of Würzburg, WürzburgD-97080, Germany
| | - Alexander J. Westermann
- Helmholtz Institute for RNA-based Infection Research, Helmholtz Centre for Infection Research, WürzburgD-97080, Germany
- Institute of Molecular Infection Biology, University of Würzburg, WürzburgD-97080, Germany
- Department of Microbiology, Biocentre, University of Würzburg, WürzburgD-97074, Germany
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9
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Wimmer F, Englert F, Wandera KG, Alkhnbashi O, Collins S, Backofen R, Beisel C. Interrogating two extensively self-targeting Type I CRISPR-Cas systems in Xanthomonas albilineans reveals distinct anti-CRISPR proteins that block DNA degradation. Nucleic Acids Res 2024; 52:769-783. [PMID: 38015466 PMCID: PMC10810201 DOI: 10.1093/nar/gkad1097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 11/29/2023] Open
Abstract
CRISPR-Cas systems store fragments of invader DNA as spacers to recognize and clear those same invaders in the future. Spacers can also be acquired from the host's genomic DNA, leading to lethal self-targeting. While self-targeting can be circumvented through different mechanisms, natural examples remain poorly explored. Here, we investigate extensive self-targeting by two CRISPR-Cas systems encoding 24 self-targeting spacers in the plant pathogen Xanthomonas albilineans. We show that the native I-C and I-F1 systems are actively expressed and that CRISPR RNAs are properly processed. When expressed in Escherichia coli, each Cascade complex binds its PAM-flanked DNA target to block transcription, while the addition of Cas3 paired with genome targeting induces cell killing. While exploring how X. albilineans survives self-targeting, we predicted putative anti-CRISPR proteins (Acrs) encoded within the bacterium's genome. Screening of identified candidates with cell-free transcription-translation systems and in E. coli revealed two Acrs, which we named AcrIC11 and AcrIF12Xal, that inhibit the activity of Cas3 but not Cascade of the respective system. While AcrF12Xal is homologous to AcrIF12, AcrIC11 shares sequence and structural homology with the anti-restriction protein KlcA. These findings help explain tolerance of self-targeting through two CRISPR-Cas systems and expand the known suite of DNA degradation-inhibiting Acrs.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Frank Englert
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Katharina G Wandera
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Omer S Alkhnbashi
- Information and Computer Science Department, King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
- Interdisciplinary Research Center for Intelligent Secure Systems (IRC-ISS), King Fahd University of Petroleum and Minerals (KFUPM), Dhahran 31261, Saudi Arabia
| | - Scott P Collins
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Rolf Backofen
- Bioinformatics group, Department of Computer Science, University of Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
- Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
- Medical Faculty, University of Würzburg, 97080 Würzburg, Germany
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10
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Graver BA, Chakravarty N, Solomon KV. Prokaryotic Argonautes for in vivo biotechnology and molecular diagnostics. Trends Biotechnol 2024; 42:61-73. [PMID: 37451948 DOI: 10.1016/j.tibtech.2023.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/18/2023]
Abstract
Prokaryotic Argonautes (pAgos) are an emerging class of programmable endonucleases that are believed to be more flexible than existing CRISPR-Cas systems and have significant potential for biotechnology. Current applications of pAgos include a myriad of molecular diagnostics and in vitro DNA assembly tools. However, efforts have historically been centered on thermophilic pAgo variants. To enable in vivo biotechnological applications such as gene editing, focus has shifted to pAgos from mesophilic organisms. We discuss what is known of pAgos, how they are being developed for various applications, and strategies to overcome current challenges to in vivo applications in prokaryotes and eukaryotes.
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Affiliation(s)
- Brett A Graver
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Namrata Chakravarty
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA
| | - Kevin V Solomon
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716, USA.
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11
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Esser SP, Rahlff J, Zhao W, Predl M, Plewka J, Sures K, Wimmer F, Lee J, Adam PS, McGonigle J, Turzynski V, Banas I, Schwank K, Krupovic M, Bornemann TLV, Figueroa-Gonzalez PA, Jarett J, Rattei T, Amano Y, Blaby IK, Cheng JF, Brazelton WJ, Beisel CL, Woyke T, Zhang Y, Probst AJ. A predicted CRISPR-mediated symbiosis between uncultivated archaea. Nat Microbiol 2023; 8:1619-1633. [PMID: 37500801 DOI: 10.1038/s41564-023-01439-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 06/23/2023] [Indexed: 07/29/2023]
Abstract
CRISPR-Cas systems defend prokaryotic cells from invasive DNA of viruses, plasmids and other mobile genetic elements. Here, we show using metagenomics, metatranscriptomics and single-cell genomics that CRISPR systems of widespread, uncultivated archaea can also target chromosomal DNA of archaeal episymbionts of the DPANN superphylum. Using meta-omics datasets from Crystal Geyser and Horonobe Underground Research Laboratory, we find that CRISPR spacers of the hosts Candidatus Altiarchaeum crystalense and Ca. A. horonobense, respectively, match putative essential genes in their episymbionts' genomes of the genus Ca. Huberiarchaeum and that some of these spacers are expressed in situ. Metabolic interaction modelling also reveals complementation between host-episymbiont systems, on the basis of which we propose that episymbionts are either parasitic or mutualistic depending on the genotype of the host. By expanding our analysis to 7,012 archaeal genomes, we suggest that CRISPR-Cas targeting of genomes associated with symbiotic archaea evolved independently in various archaeal lineages.
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Affiliation(s)
- Sarah P Esser
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Janina Rahlff
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
- Centre for Ecology and Evolution in Microbial Model Systems (EEMiS), Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Weishu Zhao
- Department of Cell and Molecular Biology, College of the Environment and Life Sciences, University of Rhode Island, Kingston, RI, USA
- Shanghai Jiao Tong University, School of Life Sciences and Biotechnology, International Center for Deep Life Investigation (IC-DLI), Shanghai Jiao Tong University, Shanghai, China
| | - Michael Predl
- Computational Systems Biology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Julia Plewka
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Katharina Sures
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Janey Lee
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Panagiotis S Adam
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Julia McGonigle
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Victoria Turzynski
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Indra Banas
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Katrin Schwank
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
- University of Regensburg, Biochemistry III, Regensburg, Germany
| | - Mart Krupovic
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit, Paris, France
| | - Till L V Bornemann
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Perla Abigail Figueroa-Gonzalez
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany
| | - Jessica Jarett
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Thomas Rattei
- Computational Systems Biology, Centre for Microbiology and Environmental Systems Science, University of Vienna, Vienna, Austria
- Doctoral School in Microbiology and Environmental Science, University of Vienna, Vienna, Austria
| | - Yuki Amano
- Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency, Tokai, Japan
| | - Ian K Blaby
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jan-Fang Cheng
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
- Medical faculty, University of Würzburg, Würzburg, Germany
| | - Tanja Woyke
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ying Zhang
- Department of Cell and Molecular Biology, College of the Environment and Life Sciences, University of Rhode Island, Kingston, RI, USA
| | - Alexander J Probst
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany.
- Group for Aquatic Microbial Ecology, Environmental Microbiology and Biotechnology, University of Duisburg-Essen, Essen, Germany.
- Centre of Water and Environmental Research (ZWU), University of Duisburg-Essen, Essen, Germany.
- Centre of Medical Biotechnology (ZMB), University of Duisburg-Essen, Essen, Germany.
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12
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Tanniche I, Nazem-Bokaee H, Scherr DM, Schlemmer S, Senger RS. A novel synthetic sRNA promoting protein overexpression in cell-free systems. Biotechnol Prog 2023; 39:e3324. [PMID: 36651906 DOI: 10.1002/btpr.3324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 10/31/2022] [Accepted: 01/11/2023] [Indexed: 01/19/2023]
Abstract
Bacterial small RNAs (sRNAs) that regulate gene expression have been engineered for uses in synthetic biology and metabolic engineering. Here, we designed a novel non-Hfq-dependent sRNA scaffold that uses a modifiable 20 nucleotide antisense binding region to target mRNAs selectively and influence protein expression. The system was developed for regulation of a fluorescent reporter in vivo using Escherichia coli, but the system was found to be more responsive and produced statistically significant results when applied to protein synthesis using in vitro cell-free systems (CFS). Antisense binding sequences were designed to target not only translation initiation regions but various secondary structures in the reporter mRNA. Targeting a high-energy stem loop structure and the 3' end of mRNA yielded protein expression knock-downs that approached 70%. Notably, targeting a low-energy stem structure near a potential RNase E binding site led to a statistically significant 65% increase in protein expression (p < 0.05). These results were not obtainable in vivo, and the underlying mechanism was translated from the reporter system to achieve better than 75% increase in recombinant diaphorase expression in a CFS. It is possible the designs developed here can be applied to improve/regulate expression of other proteins in a CFS.
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Affiliation(s)
- Imen Tanniche
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
- School of Plant & Environmental Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Hadi Nazem-Bokaee
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
- CSIRO, Black Mountain Science & Innovation Park, Canberra, Australia
| | - David M Scherr
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
| | - Sara Schlemmer
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia, USA
| | - Ryan S Senger
- Department of Biological Systems Engineering, Virginia Tech, Blacksburg, Virginia, USA
- Department of Chemical Engineering, Virginia Tech, Blacksburg, Virginia, USA
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13
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Avidan N, Levy M, Daube SS, Bar-Ziv RH. Toward Memory in a DNA Brush: Site-Specific Recombination Responsive to Polymer Density, Orientation, and Conformation. J Am Chem Soc 2023; 145:9729-9736. [PMID: 37071757 PMCID: PMC10161217 DOI: 10.1021/jacs.3c01375] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023]
Abstract
Site-specific recombination is a cellular process for the integration, inversion, and excision of DNA segments that could be tailored for memory transactions in artificial cells. Here, we demonstrate the compartmentalization of cascaded gene expression reactions in a DNA brush, starting from the cell-free synthesis of a unidirectional recombinase that exchanges information between two DNA molecules, leading to gene expression turn-on/turn-off. We show that recombination yield in the DNA brush was responsive to gene composition, density, and orientation, with kinetics faster than in a homogeneous dilute bulk solution reaction. Recombination yield scaled with a power law greater than 1 with respect to the fraction of recombining DNA polymers in a dense brush. The exponent approached either 1 or 2, depending on the intermolecular distance in the brush and the position of the recombination site along the DNA contour length, suggesting that a restricted-reach effect between the recombination sites governs the recombination yield. We further demonstrate the ability to encode the DNA recombinase in the same DNA brush with its substrate constructs, enabling multiple spatially resolved orthogonal recombination transactions within a common reaction volume. Our results highlight the DNA brush as a favorable compartment to study DNA recombination, with unique properties for encoding autonomous memory transactions in DNA-based artificial cells.
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Affiliation(s)
- Noa Avidan
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michael Levy
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Shirley S Daube
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Roy H Bar-Ziv
- Department of Chemical and Biological Physics, The Weizmann Institute of Science, Rehovot 7610001, Israel
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14
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Forsberg KJ. Anti-CRISPR Discovery: Using Magnets to Find Needles in Haystacks. J Mol Biol 2023; 435:167952. [PMID: 36638909 PMCID: PMC10073268 DOI: 10.1016/j.jmb.2023.167952] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/22/2022] [Accepted: 01/03/2023] [Indexed: 01/12/2023]
Abstract
CRISPR-Cas immune systems in bacteria and archaea protect against viral infection, which has spurred viruses to develop dedicated inhibitors of these systems called anti-CRISPRs (Acrs). Like most host-virus arms races, many diverse examples of these immune and counter-immune proteins are encoded by the genomes of bacteria, archaea, and their viruses. For the case of Acrs, it is almost certain that just a small minority of nature's true diversity has been described. In this review, I discuss the various approaches used to identify these Acrs and speculate on the future for Acr discovery. Because Acrs can determine infection outcomes in nature and regulate CRISPR-Cas activities in applied settings, they have a dual importance to both host-virus conflicts and emerging biotechnologies. Thus, revealing the largely hidden world of Acrs should provide important lessons in microbiology that have the potential to ripple far beyond the field.
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Affiliation(s)
- Kevin J Forsberg
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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15
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Illa-Berenguer E, LaFayette PR, Parrott WA. Editing efficiencies with Cas9 orthologs, Cas12a endonucleases, and temperature in rice. Front Genome Ed 2023; 5:1074641. [PMID: 37032710 PMCID: PMC10080323 DOI: 10.3389/fgeed.2023.1074641] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 03/07/2023] [Indexed: 03/19/2023] Open
Abstract
The advent of CRISPR-Cas technology has made it the genome editing tool of choice in all kingdoms of life, including plants, which can have large, highly duplicated genomes. As a result, finding adequate target sequences that meet the specificities of a given Cas nuclease on any gene of interest remains challenging in many cases. To assess target site flexibility, we tested five different Cas9/Cas12a endonucleases (SpCas9, SaCas9, St1Cas9, Mb3Cas12a, and AsCas12a) in embryogenic rice calli from Taipei 309 at 37°C (optimal temperature for most Cas9/Cas12a proteins) and 27°C (optimal temperature for tissue culture) and measured their editing rates under regular tissue culture conditions using Illumina sequencing. StCas9 and AsCas12 were not functional as tested, regardless of the temperature used. SpCas9 was the most efficient endonuclease at either temperature, regardless of whether monoallelic or biallelic edits were considered. Mb3Cas12a at 37°C was the next most efficient endonuclease. Monoallelic edits prevailed for both SaCas9 and Mb3Cas12a at 27°C, but biallelic edits prevailed at 37°C. Overall, the use of other Cas9 orthologs, the use of Cas12a endonucleases, and the optimal temperature can expand the range of targetable sequences.
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Affiliation(s)
- Eudald Illa-Berenguer
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, United States
- *Correspondence: Eudald Illa-Berenguer,
| | - Peter R. LaFayette
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, United States
| | - Wayne A. Parrott
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA, United States
- Department of Crop and Soil Sciences, University of Georgia, Athens, GA, United States
- Institute of Plant Breeding, Genetics and Genomics, University of Georgia, Athens, GA, United States
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16
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Montagud-Martínez R, Márquez-Costa R, Rodrigo G. Programmable regulation of translation by harnessing the CRISPR-Cas13 system. Chem Commun (Camb) 2023; 59:2616-2619. [PMID: 36757178 DOI: 10.1039/d3cc00058c] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The ability to control protein expression at both the transcriptional and post-transcriptional levels is instrumental for the cell to integrate multiple molecular signals and then reach high operational sophistication. Although challenging, fully artificial regulations at different levels are required for boosting systems and synthetic biology. Here, we report the development of a novel framework to regulate translation by repurposing the CRISPR-Cas13 immune system, which uses an RNA-guided ribonuclease. By exploiting a cell-free expression system for prototyping gene regulatory structures, our results demonstrate that CRISPR-dCas13a ribonucleoproteins (d means catalytically dead) can be programmed to repress or activate translation initiation. The performance assessment of the engineered systems also revealed guide RNA design principles. Moreover, we show that the system can work in vivo. This development complements the ability to regulate transcription with other CRISPR-Cas systems and offers potential applications.
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Affiliation(s)
- Roser Montagud-Martínez
- Institute for Integrative Systems Biology (I2SysBio), CSIC - University of Valencia, 46980, Paterna, Spain.
| | - Rosa Márquez-Costa
- Institute for Integrative Systems Biology (I2SysBio), CSIC - University of Valencia, 46980, Paterna, Spain.
| | - Guillermo Rodrigo
- Institute for Integrative Systems Biology (I2SysBio), CSIC - University of Valencia, 46980, Paterna, Spain.
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17
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Ecology and evolution of phages encoding anti-CRISPR proteins. J Mol Biol 2023; 435:167974. [PMID: 36690071 DOI: 10.1016/j.jmb.2023.167974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/21/2023]
Abstract
CRISPR-Cas are prokaryotic defence systems that provide protection against invasion by mobile genetic elements (MGE), including bacteriophages. MGE can overcome CRISPR-Cas defences by encoding anti-CRISPR (Acr) proteins. These proteins are produced in the early stages of the infection and inhibit the CRISPR-Cas machinery to allow phage replication. While research on Acr has mainly focused on their discovery, structure and mode of action, and their applications in biotechnology, the impact of Acr on the ecology of MGE as well as on the coevolution with their bacterial hosts only begins to be unravelled. In this review, we summarise our current understanding on the distribution of anti-CRISPR genes in MGE, the ecology of phages encoding Acr, and their coevolution with bacterial defence mechanisms. We highlight the need to use more diverse and complex experimental models to better understand the impact of anti-CRISPR in MGE-host interactions.
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18
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Huang TP, Heins ZJ, Miller SM, Wong BG, Balivada PA, Wang T, Khalil AS, Liu DR. High-throughput continuous evolution of compact Cas9 variants targeting single-nucleotide-pyrimidine PAMs. Nat Biotechnol 2023; 41:96-107. [PMID: 36076084 PMCID: PMC9849140 DOI: 10.1038/s41587-022-01410-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 06/30/2022] [Indexed: 01/25/2023]
Abstract
Despite the availability of Cas9 variants with varied protospacer-adjacent motif (PAM) compatibilities, some genomic loci-especially those with pyrimidine-rich PAM sequences-remain inaccessible by high-activity Cas9 proteins. Moreover, broadening PAM sequence compatibility through engineering can increase off-target activity. With directed evolution, we generated four Cas9 variants that together enable targeting of most pyrimidine-rich PAM sequences in the human genome. Using phage-assisted noncontinuous evolution and eVOLVER-supported phage-assisted continuous evolution, we evolved Nme2Cas9, a compact Cas9 variant, into variants that recognize single-nucleotide pyrimidine-PAM sequences. We developed a general selection strategy that requires functional editing with fully specified target protospacers and PAMs. We applied this selection to evolve high-activity variants eNme2-T.1, eNme2-T.2, eNme2-C and eNme2-C.NR. Variants eNme2-T.1 and eNme2-T.2 offer access to N4TN PAM sequences with comparable editing efficiencies as existing variants, while eNme2-C and eNme2-C.NR offer less restrictive PAM requirements, comparable or higher activity in a variety of human cell types and lower off-target activity at N4CN PAM sequences.
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Affiliation(s)
- Tony P Huang
- Merkin Institute of Transformative Technologies in Healthcare, The Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Zachary J Heins
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Shannon M Miller
- Merkin Institute of Transformative Technologies in Healthcare, The Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
| | - Brandon G Wong
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Pallavi A Balivada
- Biological Design Center, Boston University, Boston, MA, USA
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Tina Wang
- Merkin Institute of Transformative Technologies in Healthcare, The Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, USA
| | - Ahmad S Khalil
- Biological Design Center, Boston University, Boston, MA, USA.
- Department of Biomedical Engineering, Boston University, Boston, MA, USA.
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
| | - David R Liu
- Merkin Institute of Transformative Technologies in Healthcare, The Broad Institute of Harvard and MIT, Cambridge, MA, USA.
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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19
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Cas12a2 elicits abortive infection through RNA-triggered destruction of dsDNA. Nature 2023; 613:588-594. [PMID: 36599979 PMCID: PMC9811890 DOI: 10.1038/s41586-022-05559-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 11/11/2022] [Indexed: 01/05/2023]
Abstract
Bacterial abortive-infection systems limit the spread of foreign invaders by shutting down or killing infected cells before the invaders can replicate1,2. Several RNA-targeting CRISPR-Cas systems (that is, types III and VI) cause abortive-infection phenotypes by activating indiscriminate nucleases3-5. However, a CRISPR-mediated abortive mechanism that leverages indiscriminate DNase activity of an RNA-guided single-effector nuclease has yet to be observed. Here we report that RNA targeting by the type V single-effector nuclease Cas12a2 drives abortive infection through non-specific cleavage of double-stranded DNA (dsDNA). After recognizing an RNA target with an activating protospacer-flanking sequence, Cas12a2 efficiently degrades single-stranded RNA (ssRNA), single-stranded DNA (ssDNA) and dsDNA. Within cells, the activation of Cas12a2 induces an SOS DNA-damage response and impairs growth, preventing the dissemination of the invader. Finally, we harnessed the collateral activity of Cas12a2 for direct RNA detection, demonstrating that Cas12a2 can be repurposed as an RNA-guided RNA-targeting tool. These findings expand the known defensive abilities of CRISPR-Cas systems and create additional opportunities for CRISPR technologies.
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20
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Patterson AT, Styczynski MP. Rapid and Finely-Tuned Expression for Deployable Sensing Applications. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2023; 186:141-161. [PMID: 37316621 DOI: 10.1007/10_2023_223] [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: 06/16/2023]
Abstract
Organisms from across the tree of life have evolved highly efficient mechanisms for sensing molecules of interest using biomolecular machinery that can in turn be quite valuable for the development of biosensors. However, purification of such machinery for use in in vitro biosensors is costly, while the use of whole cells as in vivo biosensors often leads to long sensor response times and unacceptable sensitivity to the chemical makeup of the sample. Cell-free expression systems overcome these weaknesses by removing the requirements associated with maintaining living sensor cells, allowing for increased function in toxic environments and rapid sensor readout at a production cost that is often more reasonable than purification. Here, we focus on the challenge of implementing cell-free protein expression systems that meet the stringent criteria required for them to serve as the basis for field-deployable biosensors. Fine-tuning expression to meet these requirements can be achieved through careful selection of the sensing and output elements, as well as through optimization of reaction conditions via tuning of DNA/RNA concentrations, lysate preparation methods, and buffer conditions. Through careful sensor engineering, cell-free systems can continue to be successfully used for the production of tightly regulated, rapidly expressing genetic circuits for biosensors.
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Affiliation(s)
- Alexandra T Patterson
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA
| | - Mark P Styczynski
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
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21
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Joseph RC, Sandoval NR. Single and multiplexed gene repression in solventogenic Clostridium via Cas12a-based CRISPR interference. Synth Syst Biotechnol 2022; 8:148-156. [PMID: 36687471 PMCID: PMC9842803 DOI: 10.1016/j.synbio.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 11/28/2022] [Accepted: 12/20/2022] [Indexed: 12/25/2022] Open
Abstract
The Gram-positive, spore-forming, obligate anaerobic firmicute species that make up the Clostridium genus have broad feedstock consumption capabilities and produce value-added metabolic products, but genetic manipulation is difficult, limiting their broad appeal. CRISPR-Cas systems have recently been applied to Clostridium species, primarily using Cas9 as a counterselection marker in conjunction with plasmid-based homologous recombination. CRISPR interference is a method that reduces gene expression of specific genes via precision targeting of a nuclease deficient Cas effector protein. Here, we develop a dCas12a-based CRISPR interference system for transcriptional gene repression in multiple mesophilic Clostridium species. We show the Francisella novicida Cas12a-based system has a broader applicability due to the low GC content in Clostridium species compared to CRISPR Cas systems derived from other bacteria. We demonstrate >99% reduction in transcript levels of targeted genes in Clostridium acetobutylicum and >75% reduction in Clostridium pasteurianum. We also demonstrate multiplexed repression via use of a single synthetic CRISPR array, achieving 99% reduction in targeted gene expression and elucidating a unique metabolic profile for their reduced expression. Overall, this work builds a foundation for high throughput genetic screens without genetic editing, a key limitation in current screening methods used in the Clostridium community.
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Affiliation(s)
| | - Nicholas R. Sandoval
- Corresponding author. Department of Chemical and Biomolecular Engineering, Tulane University, St. Charles Ave, New Orleans, LA, 70118, United States.
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22
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Wu WY, Mohanraju P, Liao C, Adiego-Pérez B, Creutzburg SCA, Makarova KS, Keessen K, Lindeboom TA, Khan TS, Prinsen S, Joosten R, Yan WX, Migur A, Laffeber C, Scott DA, Lebbink JHG, Koonin EV, Beisel CL, van der Oost J. The miniature CRISPR-Cas12m effector binds DNA to block transcription. Mol Cell 2022; 82:4487-4502.e7. [PMID: 36427491 DOI: 10.1016/j.molcel.2022.11.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 08/01/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022]
Abstract
CRISPR-Cas are prokaryotic adaptive immune systems. Cas nucleases generally use CRISPR-derived RNA guides to specifically bind and cleave DNA or RNA targets. Here, we describe the experimental characterization of a bacterial CRISPR effector protein Cas12m representing subtype V-M. Despite being less than half the size of Cas12a, Cas12m catalyzes auto-processing of a crRNA guide, recognizes a 5'-TTN' protospacer-adjacent motif (PAM), and stably binds a guide-complementary double-stranded DNA (dsDNA). Cas12m has a RuvC domain with a non-canonical catalytic site and accordingly is incapable of guide-dependent cleavage of target nucleic acids. Despite lacking target cleavage activity, the high binding affinity of Cas12m to dsDNA targets allows for interference as demonstrated by its ability to protect bacteria against invading plasmids through silencing invader transcription and/or replication. Based on these molecular features, we repurposed Cas12m by fusing it to a cytidine deaminase that resulted in base editing within a distinct window.
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Affiliation(s)
- Wen Y Wu
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
| | - Prarthana Mohanraju
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Chunyu Liao
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Belén Adiego-Pérez
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Sjoerd C A Creutzburg
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Kira S Makarova
- National Centre for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Karlijn Keessen
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Timon A Lindeboom
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Tahseen S Khan
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Stijn Prinsen
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Rob Joosten
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | | | - Anzhela Migur
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Charlie Laffeber
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands
| | | | - Joyce H G Lebbink
- Department of Molecular Genetics, Oncode Institute, Erasmus MC Cancer Institute, Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands; Department of Radiation Oncology, Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands
| | - Eugene V Koonin
- National Centre for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - 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
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
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23
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Ranji Charna A, Des Soye BJ, Ntai I, Kelleher NL, Jewett MC. An efficient cell-free protein synthesis platform for producing proteins with pyrrolysine-based noncanonical amino acids. Biotechnol J 2022; 17:e2200096. [PMID: 35569121 PMCID: PMC9452482 DOI: 10.1002/biot.202200096] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/04/2022] [Accepted: 05/09/2022] [Indexed: 11/08/2022]
Abstract
Incorporation of noncanonical amino acids (ncAAs) into proteins opens new opportunities in biotechnology and synthetic biology. Pyrrolysine (Pyl)-based ncAAs are some of the most predominantly used, but expression systems suffer from low yields. Here, we report a highly efficient cell-free protein synthesis (CFPS) platform for site-specific incorporation of Pyl-based ncAAs into proteins using amber suppression. This platform is based on cellular extracts derived from genomically recoded Escherichia coli lacking release factor 1 and enhanced through deletion of endonuclease A. To enable ncAA incorporation, orthogonal translation system (OTS) components (i.e., the orthogonal transfer RNA [tRNA] and orthogonal aminoacyl tRNA synthetase) were coexpressed in the source strain prior to lysis and the orthogonal tRNACUA Pyl that decodes the amber codon was further enriched in the CFPS reaction via co-synthesis with the product. Using this platform, we demonstrate production of up to 442 ± 23 µg/mL modified superfolder green fluorescent protein (sfGFP) containing a single Pyl-based ncAA at high (>95%) suppression efficiency, as well as sfGFP variants harboring multiple, identical ncAAs. Our CFPS platform can be used for the synthesis of modified proteins containing multiple precisely positioned, genetically encoded Pyl-based ncAAs. We anticipate that it will facilitate more general use of CFPS in synthetic biology.
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Affiliation(s)
- Arnaz Ranji Charna
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Benjamin J Des Soye
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Ioanni Ntai
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
| | - Neil L Kelleher
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Department of Chemistry, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois, USA
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois, USA
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois, USA
- Member, Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Northwestern University, Chicago, Illinois, USA
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24
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Lin X, Zhou C, Wang T, Huang X, Chen J, Li Z, Zhang J, Lu Y. CO2-elevated cell-free protein synthesis. Synth Syst Biotechnol 2022; 7:911-917. [PMID: 35664930 PMCID: PMC9136254 DOI: 10.1016/j.synbio.2022.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/20/2022] [Accepted: 05/12/2022] [Indexed: 11/26/2022] Open
Abstract
Gases are the vital nutrition of all organisms as the precursor of metabolism pathways. As a potential biological process, protein synthesis is inevitably regulated by gas transport and utilization. However, the effect of carbon dioxide (CO2) present in many metabolic pathways on protein synthesis has not been studied well. In this work, carbon dioxide combined with oxygen was employed for cell-free protein synthesis (CFPS) in the tube-in-tube reactor with precise control of gas concentration. In this in vitro system, gases could directly affect the protein synthesis process without transmembrane transport. Varied concentrations of carbon dioxide (0–1%) and constant oxygen concentration (21%) were employed for CFPS to assess the effects. The cell-free reactions with 0.3% CO2 and 21% O2 showed the highest protein yields. The combined effect of CO2 and O2 also resulted in relatively high protein expression under high oxygen conditions (0.3% CO2 and 100% O2). Moreover, metabolomics assays were performed to gain insight into metabolic changes, which showed that CO2 slightly improved energy metabolism and redox balance. In particular, the extra supplied CO2 activated the decarboxylating reactions and removed toxic metabolites to recover the protein synthesis activity. The exploration of CO2 on protein synthesis could provide guiding implications for basic studies and biomanufacturing.
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25
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Romantseva E, Alperovich N, Ross D, Lund SP, Strychalski EA. Effects of DNA template preparation on variability in cell-free protein production. Synth Biol (Oxf) 2022; 7:ysac015. [PMID: 36046152 PMCID: PMC9425043 DOI: 10.1093/synbio/ysac015] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 07/01/2022] [Accepted: 08/12/2022] [Indexed: 08/08/2023] Open
Abstract
DNA templates for protein production remain an unexplored source of variability in the performance of cell-free expression (CFE) systems. To characterize this variability, we investigated the effects of two common DNA extraction methodologies, a postprocessing step and manual versus automated preparation on protein production using CFE. We assess the concentration of the DNA template, the quality of the DNA template in terms of physical damage and the quality of the DNA solution in terms of purity resulting from eight DNA preparation workflows. We measure the variance in protein titer and rate of protein production in CFE reactions associated with the biological replicate of the DNA template, the technical replicate DNA solution prepared with the same workflow and the measurement replicate of nominally identical CFE reactions. We offer practical guidance for preparing and characterizing DNA templates to achieve acceptable variability in CFE performance.
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Affiliation(s)
| | - Nina Alperovich
- National Institute of Standards and Technology, Gaithersburg, MD USA
| | - David Ross
- National Institute of Standards and Technology, Gaithersburg, MD USA
| | - Steven P Lund
- National Institute of Standards and Technology, Gaithersburg, MD USA
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26
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Vialetto E, Yu Y, Collins SP, Wandera KG, Barquist L, Beisel CL. A target expression threshold dictates invader defense and prevents autoimmunity by CRISPR-Cas13. Cell Host Microbe 2022; 30:1151-1162.e6. [PMID: 35690065 PMCID: PMC9590104 DOI: 10.1016/j.chom.2022.05.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/30/2022] [Accepted: 05/17/2022] [Indexed: 11/20/2022]
Abstract
CRISPR-Cas systems must enact robust immunity against foreign genetic material without inducing cytotoxic autoimmunity. For type VI systems that use Cas13 nucleases and recognize RNA targets, immune activation requires extensive CRISPR RNA (crRNA) guide-target complementarity and a target-flanking motif. Here, we report a third requirement shaping the immune response: the expression of the target transcript exceeding a threshold. We found that endogenous non-essential transcripts targeted by crRNAs rarely elicited autoimmunity. Instead, autoimmune induction required over-expressing the targeted transcripts above a threshold. A genome-wide screen confirmed target expression levels as a global determinant of cytotoxic autoimmunity and revealed that this threshold shifts with each guide-target pair. This threshold further ensured defense against a lytic bacteriophage yet allowed the tolerance of a targeted beneficial gene expressed from an invading plasmid. These findings establish target expression levels as an additional criterion for immune defense by RNA-targeting CRISPR-Cas systems, preventing autoimmunity and distinguishing pathogenic and benign invaders.
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Affiliation(s)
- Elena Vialetto
- 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
| | - Scott P Collins
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA
| | - Katharina G Wandera
- 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
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany; Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC 27695, USA; Medical Faculty, University of Würzburg, 97080 Würzburg, Germany.
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27
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Rhea KA, McDonald ND, Cole SD, Noireaux V, Lux MW, Buckley PE. Variability in cell-free expression reactions can impact qualitative genetic circuit characterization. Synth Biol (Oxf) 2022; 7:ysac011. [PMID: 35966404 PMCID: PMC9365049 DOI: 10.1093/synbio/ysac011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 06/24/2022] [Accepted: 08/01/2022] [Indexed: 09/21/2023] Open
Abstract
Cell-free expression systems provide a suite of tools that are used in applications from sensing to biomanufacturing. One of these applications is genetic circuit prototyping, where the lack of cloning is required and a high degree of control over reaction components and conditions enables rapid testing of design candidates. Many studies have shown utility in the approach for characterizing genetic regulation elements, simple genetic circuit motifs, protein variants or metabolic pathways. However, variability in cell-free expression systems is a known challenge, whether between individuals, laboratories, instruments, or batches of materials. While the issue of variability has begun to be quantified and explored, little effort has been put into understanding the implications of this variability. For genetic circuit prototyping, it is unclear when and how significantly variability in reaction activity will impact qualitative assessments of genetic components, e.g. relative activity between promoters. Here, we explore this question by assessing DNA titrations of seven genetic circuits of increasing complexity using reaction conditions that ostensibly follow the same protocol but vary by person, instrument and material batch. Although the raw activities vary widely between the conditions, by normalizing within each circuit across conditions, reasonably consistent qualitative performance emerges for the simpler circuits. For the most complex case involving expression of three proteins, we observe a departure from this qualitative consistency, offering a provisional cautionary line where normal variability may disrupt reliable reuse of prototyping results. Our results also suggest that a previously described closed loop controller circuit may help to mitigate such variability, encouraging further work to design systems that are robust to variability. Graphical Abstract.
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Affiliation(s)
- Katherine A Rhea
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Nathan D McDonald
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Stephanie D Cole
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Matthew W Lux
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
| | - Patricia E Buckley
- US Army Combat Capabilities Development Command Chemical Biological Center, Aberdeen Proving Ground, MD, USA
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28
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Genomic and epigenetic landscapes drive CRISPR-based genome editing in Bifidobacterium. Proc Natl Acad Sci U S A 2022; 119:e2205068119. [PMID: 35857876 PMCID: PMC9335239 DOI: 10.1073/pnas.2205068119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Bifidobacterium is a commensal bacterial genus ubiquitous in the human gastrointestinal tract, which is associated with a range of health benefits. The advent of CRISPR-based genome editing technologies provides opportunities to investigate the genetics of important bacteria and transcend the lack of genetic tools in bifidobacteria to study the basis for their health-promoting attributes. Here, we repurpose the endogenous type I-G CRISPR-Cas system and adopt an exogenous CRISPR base editor for genome engineering in B. animalis subsp. lactis, demonstrating that both genomic and epigenetic contexts drive editing outcomes across strains. We reprogrammed the endogenous type I-G system to screen for naturally occurring large deletions up to 27 kb and to generate a 500-bp deletion in tetW to abolish tetracycline resistance. A CRISPR-cytosine base editor was optimized to install C•G-to-T•A amber mutations to resensitize multiple B. lactis strains to tetracycline. Remarkably, we uncovered epigenetic patterns that are distributed unevenly among B. lactis strains, despite their genomic homogeneity, that may contribute to editing efficiency variability. Insights were also expanded to Bifidobacterium longum subsp. infantis to emphasize the broad relevance of these findings. This study highlights the need to develop individualized CRISPR-based genome engineering approaches for distinct bacterial strains and opens avenues for engineering of next generation probiotics.
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29
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A microfluidic optimal experimental design platform for forward design of cell-free genetic networks. Nat Commun 2022; 13:3626. [PMID: 35750678 PMCID: PMC9232554 DOI: 10.1038/s41467-022-31306-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 06/14/2022] [Indexed: 12/20/2022] Open
Abstract
Cell-free protein synthesis has been widely used as a “breadboard” for design of synthetic genetic networks. However, due to a severe lack of modularity, forward engineering of genetic networks remains challenging. Here, we demonstrate how a combination of optimal experimental design and microfluidics allows us to devise dynamic cell-free gene expression experiments providing maximum information content for subsequent non-linear model identification. Importantly, we reveal that applying this methodology to a library of genetic circuits, that share common elements, further increases the information content of the data resulting in higher accuracy of model parameters. To show modularity of model parameters, we design a pulse decoder and bistable switch, and predict their behaviour both qualitatively and quantitatively. Finally, we update the parameter database and indicate that network topology affects parameter estimation accuracy. Utilizing our methodology provides us with more accurate model parameters, a necessity for forward engineering of complex genetic networks. Characterization of cell-free genetic networks is inherently difficult. Here the authors use optimal experimental design and microfluidics to improve characterization, demonstrating modularity and predictability of parts in applied test cases.
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30
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Wandera KG, Alkhnbashi OS, Bassett HVI, Mitrofanov A, Hauns S, Migur A, Backofen R, Beisel CL. Anti-CRISPR prediction using deep learning reveals an inhibitor of Cas13b nucleases. Mol Cell 2022; 82:2714-2726.e4. [PMID: 35649413 DOI: 10.1016/j.molcel.2022.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Revised: 03/25/2022] [Accepted: 05/03/2022] [Indexed: 11/28/2022]
Abstract
As part of the ongoing bacterial-phage arms race, CRISPR-Cas systems in bacteria clear invading phages whereas anti-CRISPR proteins (Acrs) in phages inhibit CRISPR defenses. Known Acrs have proven extremely diverse, complicating their identification. Here, we report a deep learning algorithm for Acr identification that revealed an Acr against type VI-B CRISPR-Cas systems. The algorithm predicted numerous putative Acrs spanning almost all CRISPR-Cas types and subtypes, including over 7,000 putative type IV and VI Acrs not predicted by other algorithms. By performing a cell-free screen for Acr hits against type VI-B systems, we identified a potent inhibitor of Cas13b nucleases we named AcrVIB1. AcrVIB1 blocks Cas13b-mediated defense against a targeted plasmid and lytic phage, and its inhibitory function principally occurs upstream of ribonucleoprotein complex formation. Overall, our work helps expand the known Acr universe, aiding our understanding of the bacteria-phage arms race and the use of Acrs to control CRISPR technologies.
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Affiliation(s)
- Katharina G Wandera
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Omer S Alkhnbashi
- Information and Computer Science Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
| | - Harris V I Bassett
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | | | - Sven Hauns
- Universität Freiburg, 79098 Freiburg, Germany
| | - Anzhela Migur
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Rolf Backofen
- Universität Freiburg, 79098 Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, University of Freiburg, 79098 Freiburg, 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.
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31
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McGaw C, Garrity AJ, Munoz GZ, Haswell JR, Sengupta S, Keston-Smith E, Hunnewell P, Ornstein A, Bose M, Wessells Q, Jakimo N, Yan P, Zhang H, Alfonse LE, Ziblat R, Carte JM, Lu WC, Cerchione D, Hilbert B, Sothiselvam S, Yan WX, Cheng DR, Scott DA, DiTommaso T, Chong S. Engineered Cas12i2 is a versatile high-efficiency platform for therapeutic genome editing. Nat Commun 2022; 13:2833. [PMID: 35595757 PMCID: PMC9122993 DOI: 10.1038/s41467-022-30465-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 05/03/2022] [Indexed: 12/11/2022] Open
Abstract
The CRISPR-Cas type V-I is a family of Cas12i-containing programmable nuclease systems guided by a short crRNA without requirement for a tracrRNA. Here we present an engineered Type V-I CRISPR system (Cas12i), ABR-001, which utilizes a tracr-less guide RNA. The compact Cas12i effector is capable of self-processing pre-crRNA and cleaving dsDNA targets, which facilitates versatile delivery options and multiplexing, respectively. We apply an unbiased mutational scanning approach to enhance initially low editing activity of Cas12i2. The engineered variant, ABR-001, exhibits broad genome editing capability in human cell lines, primary T cells, and CD34+ hematopoietic stem and progenitor cells, with both robust efficiency and high specificity. In addition, ABR-001 achieves a high level of genome editing when delivered via AAV vector to HEK293T cells. This work establishes ABR-001 as a versatile, specific, and high-performance platform for ex vivo and in vivo gene therapy.
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Affiliation(s)
- Colin McGaw
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Anthony J Garrity
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Gabrielle Z Munoz
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Jeffrey R Haswell
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Sejuti Sengupta
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Elise Keston-Smith
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | | | - Alexa Ornstein
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Mishti Bose
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Quinton Wessells
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Noah Jakimo
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Paul Yan
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Huaibin Zhang
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Lauren E Alfonse
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Roy Ziblat
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Jason M Carte
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Wei-Cheng Lu
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Derek Cerchione
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Brendan Hilbert
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | | | - Winston X Yan
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - David R Cheng
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - David A Scott
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
| | - Tia DiTommaso
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA.
| | - Shaorong Chong
- Arbor Biotechnologies, 20 Acorn Park Drive, Tower 500, Cambridge, MA, USA
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32
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Lin P, Shen G, Guo K, Qin S, Pu Q, Wang Z, Gao P, Xia Z, Khan N, Jiang J, Xia Q, Wu M. Type III CRISPR-based RNA editing for programmable control of SARS-CoV-2 and human coronaviruses. Nucleic Acids Res 2022; 50:e47. [PMID: 35166837 PMCID: PMC9071467 DOI: 10.1093/nar/gkac016] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 12/20/2021] [Accepted: 01/30/2022] [Indexed: 01/18/2023] Open
Abstract
Gene-editing technologies, including the widespread usage of CRISPR endonucleases, have the potential for clinical treatments of various human diseases. Due to the rapid mutations of SARS-CoV-2, specific and effective prevention and treatment by CRISPR toolkits for coronavirus disease 2019 (COVID-19) are urgently needed to control the current pandemic spread. Here, we designed Type III CRISPR endonuclease antivirals for coronaviruses (TEAR-CoV) as a therapeutic to combat SARS-CoV-2 infection. We provided a proof of principle demonstration that TEAR-CoV-based RNA engineering approach leads to RNA-guided transcript degradation both in vitro and in eukaryotic cells, which could be used to broadly target RNA viruses. We report that TEAR-CoV not only cleaves SARS-CoV-2 genome and mRNA transcripts, but also degrades live influenza A virus (IAV), impeding viral replication in cells and in mice. Moreover, bioinformatics screening of gRNAs along RNA sequences reveals that a group of five gRNAs (hCoV-gRNAs) could potentially target 99.98% of human coronaviruses. TEAR-CoV also exerted specific targeting and cleavage of common human coronaviruses. The fast design and broad targeting of TEAR-CoV may represent a versatile antiviral approach for SARS-CoV-2 or potentially other emerging human coronaviruses.
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Affiliation(s)
- Ping Lin
- Biological Science Research Center, Southwest University, Chongqing 400715, China
- Wound Trauma Medical Center, State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Guanwang Shen
- Biological Science Research Center, Southwest University, Chongqing 400715, China
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Kai Guo
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Shugang Qin
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Qinqin Pu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Zhihan Wang
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Pan Gao
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Zhenwei Xia
- Department of Pediatrics, Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nadeem Khan
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Jianxin Jiang
- Wound Trauma Medical Center, State Key Laboratory of Trauma, Burns and Combined Injury, Daping Hospital, Army Medical University, Chongqing 400042, China
| | - Qingyou Xia
- Biological Science Research Center, Southwest University, Chongqing 400715, China
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
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33
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Fuchs RT, Curcuru JL, Mabuchi M, Noireterre A, Weigele PR, Sun Z, Robb GB. Characterization of Cme and Yme thermostable Cas12a orthologs. Commun Biol 2022; 5:325. [PMID: 35388146 PMCID: PMC8986864 DOI: 10.1038/s42003-022-03275-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 03/16/2022] [Indexed: 11/16/2022] Open
Abstract
CRISPR-Cas12a proteins are RNA-guided endonucleases that cleave invading DNA containing target sequences adjacent to protospacer adjacent motifs (PAM). Cas12a orthologs have been repurposed for genome editing in non-native organisms by reprogramming them with guide RNAs to target specific sites in genomic DNA. After single-turnover dsDNA target cleavage, multiple-turnover, non-specific single-stranded DNA cleavage in trans is activated. This property has been utilized to develop in vitro assays to detect the presence of specific DNA target sequences. Most applications of Cas12a use one of three well-studied enzymes. Here, we characterize the in vitro activity of two previously unknown Cas12a orthologs. These enzymes are active at higher temperatures than widely used orthologs and have subtle differences in PAM preference, on-target cleavage, and trans nuclease activity. Together, our results enable refinement of Cas12a-based in vitro assays especially when elevated temperature is desirable.
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Affiliation(s)
- Ryan T Fuchs
- New England Biolabs Inc, Ipswich, MA, 01938, USA
| | | | | | - Audrey Noireterre
- New England Biolabs Inc, Ipswich, MA, 01938, USA
- Département de Biologie Cellulaire (BICEL), Université de Genève, CH - 1211, Genève 4, Switzerland
| | | | - Zhiyi Sun
- New England Biolabs Inc, Ipswich, MA, 01938, USA
| | - G Brett Robb
- New England Biolabs Inc, Ipswich, MA, 01938, USA.
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Tickman BI, Burbano DA, Chavali VP, Kiattisewee C, Fontana J, Khakimzhan A, Noireaux V, Zalatan JG, Carothers JM. Multi-layer CRISPRa/i circuits for dynamic genetic programs in cell-free and bacterial systems. Cell Syst 2022; 13:215-229.e8. [PMID: 34800362 DOI: 10.1016/j.cels.2021.10.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/24/2021] [Accepted: 10/26/2021] [Indexed: 11/29/2022]
Abstract
CRISPR-Cas transcriptional circuits hold great promise as platforms for engineering metabolic networks and information processing circuits. Historically, prokaryotic CRISPR control systems have been limited to CRISPRi. Creating approaches to integrate CRISPRa for transcriptional activation with existing CRISPRi-based systems would greatly expand CRISPR circuit design space. Here, we develop design principles for engineering prokaryotic CRISPRa/i genetic circuits with network topologies specified by guide RNAs. We demonstrate that multi-layer CRISPRa/i cascades and feedforward loops can operate through the regulated expression of guide RNAs in cell-free expression systems and E. coli. We show that CRISPRa/i circuits can program complex functions by designing type 1 incoherent feedforward loops acting as fold-change detectors and tunable pulse-generators. By investigating how component characteristics relate to network properties such as depth, width, and speed, this work establishes a framework for building scalable CRISPRa/i circuits as regulatory programs in cell-free expression systems and bacterial hosts. A record of this paper's transparent peer review process is included in the supplemental information.
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Affiliation(s)
- Benjamin I Tickman
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA
| | - Diego Alba Burbano
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA; Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA
| | - Venkata P Chavali
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA
| | - Cholpisit Kiattisewee
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA
| | - Jason Fontana
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA
| | - Aset Khakimzhan
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, USA
| | - Jesse G Zalatan
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA; Department of Chemistry, University of Washington, Seattle, WA 98195, USA.
| | - James M Carothers
- Molecular Engineering & Sciences Institute and Center for Synthetic Biology, University of Washington, Seattle, WA 98195, USA; Department of Chemical Engineering, University of Washington, Seattle, WA 98195, USA.
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Batista AC, Levrier A, Soudier P, Voyvodic PL, Achmedov T, Reif-Trauttmansdorff T, DeVisch A, Cohen-Gonsaud M, Faulon JL, Beisel CL, Bonnet J, Kushwaha M. Differentially Optimized Cell-Free Buffer Enables Robust Expression from Unprotected Linear DNA in Exonuclease-Deficient Extracts. ACS Synth Biol 2022; 11:732-746. [PMID: 35034449 DOI: 10.1021/acssynbio.1c00448] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The use of linear DNA templates in cell-free systems promises to accelerate the prototyping and engineering of synthetic gene circuits. A key challenge is that linear templates are rapidly degraded by exonucleases present in cell extracts. Current approaches tackle the problem by adding exonuclease inhibitors and DNA-binding proteins to protect the linear DNA, requiring additional time- and resource-intensive steps. Here, we delete the recBCD exonuclease gene cluster from the Escherichia coli BL21 genome. We show that the resulting cell-free systems, with buffers optimized specifically for linear DNA, enable near-plasmid levels of expression from σ70 promoters in linear DNA templates without employing additional protection strategies. When using linear or plasmid DNA templates at the buffer calibration step, the optimal potassium glutamate concentrations obtained when using linear DNA were consistently lower than those obtained when using plasmid DNA for the same extract. We demonstrate the robustness of the exonuclease deficient extracts across seven different batches and a wide range of experimental conditions across two different laboratories. Finally, we illustrate the use of the ΔrecBCD extracts for two applications: toehold switch characterization and enzyme screening. Our work provides a simple, efficient, and cost-effective solution for using linear DNA templates in cell-free systems and highlights the importance of specifically tailoring buffer composition for the final experimental setup. Our data also suggest that similar exonuclease deletion strategies can be applied to other species suitable for cell-free synthetic biology.
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Affiliation(s)
- Angelo Cardoso Batista
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
| | - Antoine Levrier
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Paul Soudier
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Peter L. Voyvodic
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Tatjana Achmedov
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | | | - Angelique DeVisch
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Martin Cohen-Gonsaud
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Jean-Loup Faulon
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
| | - 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
| | - Jerome Bonnet
- Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, University of Montpellier, 34090 Montpellier, France
| | - Manish Kushwaha
- Université Paris-Saclay, INRAe, AgroParisTech, Micalis Institute, 78352 Jouy-en-Josas, France
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36
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Wimmer F, Mougiakos I, Englert F, Beisel CL. Rapid cell-free characterization of multi-subunit CRISPR effectors and transposons. Mol Cell 2022; 82:1210-1224.e6. [PMID: 35216669 DOI: 10.1016/j.molcel.2022.01.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 11/30/2021] [Accepted: 01/26/2022] [Indexed: 11/25/2022]
Abstract
CRISPR-Cas biology and technologies have been largely shaped to date by the characterization and use of single-effector nucleases. By contrast, multi-subunit effectors dominate natural systems, represent emerging technologies, and were recently associated with RNA-guided DNA transposition. This disconnect stems from the challenge of working with multiple protein subunits in vitro and in vivo. Here, we apply cell-free transcription-translation (TXTL) systems to radically accelerate the characterization of multi-subunit CRISPR effectors and transposons. Numerous DNA constructs can be combined in one TXTL reaction, yielding defined biomolecular readouts in hours. Using TXTL, we mined phylogenetically diverse I-E effectors, interrogated extensively self-targeting I-C and I-F systems, and elucidated targeting rules for I-B and I-F CRISPR transposons using only DNA-binding components. We further recapitulated DNA transposition in TXTL, which helped reveal a distinct branch of I-B CRISPR transposons. These capabilities will facilitate the study and exploitation of the broad yet underexplored diversity of CRISPR-Cas systems and transposons.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Ioannis Mougiakos
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 97080 Würzburg, Germany
| | - Frank Englert
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), 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.
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37
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Lee KZ, Mechikoff MA, Parasa MK, Rankin TJ, Pandolfi P, Fitzgerald KS, Hillman ET, Solomon KV. Repurposing the Homing Endonuclease I-SceI for Positive Selection and Development of Gene-Editing Technologies. ACS Synth Biol 2022; 11:53-60. [PMID: 35007422 DOI: 10.1021/acssynbio.1c00340] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Prokaryote genomes encode diverse programmable DNA endonucleases with significant potential for biotechnology and gene editing. However, these endonucleases differ significantly in their properties, which must be screened and measured. While positive selection screens based on ccdB and barnase have been developed to evaluate such proteins, their high levels of toxicity make them challenging to use. Here, we develop and validate a more robust positive selection screen based on the homing endonuclease I-SceI. Candidate endonucleases target and cure the I-SceI expression plasmid preventing induction of I-SceI-mediated double strand DNA breaks that lead to cell death in E. coli. We validated this screen to measure the relative activity of SpCas9, xCas9, and eSpCas9 and demonstrated an ability to enrich for more active endonuclease variants from a mixed population. This system may be applied in high throughput to rapidly characterize novel programmable endonucleases and be adapted for directed evolution of endonuclease function.
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Affiliation(s)
- Kok Zhi Lee
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, Indiana 47907-2093, United States
| | - Michael A. Mechikoff
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, Indiana 47907-2093, United States
| | - Mrugesh Krishna Parasa
- Weldon School of Biomedical Engineering, Purdue University, 206 S Martin Jischke Drive, West Lafayette, Indiana 47907-2093, United States
- Department of Chemical & Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, Delaware 19716, United States
| | - Tyler J. Rankin
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907-2054, United States
| | - Paula Pandolfi
- Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, Indiana 47907-2054, United States
| | - Kevin S. Fitzgerald
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, Indiana 47907-2093, United States
| | - Ethan T. Hillman
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, Indiana 47907-2093, United States
- Purdue University Interdisciplinary Life Science Program (PULSe), Purdue University, 155 South Grant Street, West Lafayette, Indiana 47907, United States
| | - Kevin V. Solomon
- Department of Agricultural and Biological Engineering, Purdue University, 225 South University Street, West Lafayette, Indiana 47907-2093, United States
- Department of Chemical & Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, Delaware 19716, United States
- Purdue University Interdisciplinary Life Science Program (PULSe), Purdue University, 155 South Grant Street, West Lafayette, Indiana 47907, United States
- Laboratory of Renewable Resources Engineering (LORRE), Purdue University, 500 Central Drive, West Lafayette, Indiana 47907-2022, United States
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38
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Shelake RM, Pramanik D, Kim JY. In Vivo Rapid Investigation of CRISPR-Based Base Editing Components in Escherichia coli (IRI-CCE): A Platform for Evaluating Base Editing Tools and Their Components. Int J Mol Sci 2022; 23:ijms23031145. [PMID: 35163069 PMCID: PMC8834901 DOI: 10.3390/ijms23031145] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 02/04/2023] Open
Abstract
Rapid assessment of clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas)-based genome editing (GE) tools and their components is a critical aspect for successful GE applications in different organisms. In many bacteria, double-strand breaks (DSBs) generated by CRISPR/Cas tool generally cause cell death due to the lack of an efficient nonhomologous end-joining pathway and restricts its use. CRISPR-based DSB-free base editors (BEs) have been applied for precise nucleotide (nt) editing in bacteria, which does not need to make DSBs. However, optimization of newer BE tools in bacteria is challenging owing to the toxic effects of BE reagents expressed using strong promoters. Improved variants of two main BEs, cytidine base editor (CBE) and adenine base editor (ABE), capable of converting C to T and A to G, respectively, have been recently developed but yet to be tested for editing characteristics in bacteria. Here, we report a platform for in vivo rapid investigation of CRISPR-BE components in Escherichia coli (IRI-CCE) comprising a combination of promoters and terminators enabling the expression of nCas9-based BE and sgRNA to nontoxic levels, eventually leading to successful base editing. We demonstrate the use of IRI-CCE to characterize different variants of CBEs (PmCDA1, evoCDA1, APOBEC3A) and ABEs (ABE8e, ABE9e) for bacteria, exhibiting that each independent BE has its specific editing pattern for a given target site depending on protospacer length. In summary, CRISPR-BE components expressed without lethal effects on cell survival in the IRI-CCE allow an analysis of various BE tools, including cloned biopart modules and sgRNAs.
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Affiliation(s)
- Rahul Mahadev Shelake
- Division of Applied Life Science (BK21 FOUR Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Korea;
- Correspondence: (R.M.S.); (J.-Y.K.)
| | - Dibyajyoti Pramanik
- Division of Applied Life Science (BK21 FOUR Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Korea;
| | - Jae-Yean Kim
- Division of Applied Life Science (BK21 FOUR Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 52828, Korea;
- Division of Life Science, Gyeongsang National University, 501 Jinju-daero, Jinju 52828, Korea
- Correspondence: (R.M.S.); (J.-Y.K.)
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39
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Romantseva EF, Tack DS, Alperovich N, Ross D, Strychalski EA. Best Practices for DNA Template Preparation Toward Improved Reproducibility in Cell-Free Protein Production. Methods Mol Biol 2022; 2433:3-50. [PMID: 34985735 DOI: 10.1007/978-1-0716-1998-8_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Performance variability is a common challenge in cell-free protein production and hinders a wider adoption of these systems for both research and biomanufacturing. While the inherent stochasticity and complexity of biology likely contributes to variability, other systematic factors may also play a role, including the source and preparation of the cell extract, the composition of the supplemental reaction buffer, the facility at which experiments are conducted, and the human operator (Cole et al. ACS Synth Biol 8:2080-2091, 2019). Variability in protein production could also arise from differences in the DNA template-specifically the amount of functional DNA added to a cell-free reaction and the quality of the DNA preparation in terms of contaminants and strand breakage. Here, we present protocols and suggest best practices optimized for DNA template preparation and quantitation for cell-free systems toward reducing variability in cell-free protein production.
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Affiliation(s)
| | - Drew S Tack
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Nina Alperovich
- National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - David Ross
- National Institute of Standards and Technology, Gaithersburg, MD, USA
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40
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Wimmer F, Englert F, Beisel CL. A TXTL-Based Assay to Rapidly Identify PAMs for CRISPR-Cas Systems with Multi-Protein Effector Complexes. Methods Mol Biol 2022; 2433:391-411. [PMID: 34985758 DOI: 10.1007/978-1-0716-1998-8_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Type I CRISPR-Cas systems represent the most common and diverse type of these prokaryotic defense systems and are being harnessed for a growing set of applications. As these systems rely on multi-protein effector complexes, their characterization remains challenging. Here, we report a rapid and straightforward method to characterize these systems in a cell-free transcription-translation (TXTL) system. A ribonucleoprotein complex is produced and binds to its target next to a recognized PAM, thereby preventing the targeted sequence from being cleaved by a restriction enzyme. Selection for uncleaved targeted plasmids leads to an enrichment of recognized sequences within a PAM library. This assay will aid the exploration of CRISPR-Cas diversity and evolution and help contribute new systems for CRISPR technologies and applications.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Frank Englert
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany.
- Medical Faculty, University of Würzburg, Würzburg, Germany.
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41
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Brookwell A, Oza JP, Caschera F. Biotechnology Applications of Cell-Free Expression Systems. Life (Basel) 2021; 11:life11121367. [PMID: 34947898 PMCID: PMC8705439 DOI: 10.3390/life11121367] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 12/13/2022] Open
Abstract
Cell-free systems are a rapidly expanding platform technology with an important role in the engineering of biological systems. The key advantages that drive their broad adoption are increased efficiency, versatility, and low cost compared to in vivo systems. Traditionally, in vivo platforms have been used to synthesize novel and industrially relevant proteins and serve as a testbed for prototyping numerous biotechnologies such as genetic circuits and biosensors. Although in vivo platforms currently have many applications within biotechnology, they are hindered by time-constraining growth cycles, homeostatic considerations, and limited adaptability in production. Conversely, cell-free platforms are not hindered by constraints for supporting life and are therefore highly adaptable to a broad range of production and testing schemes. The advantages of cell-free platforms are being leveraged more commonly by the biotechnology community, and cell-free applications are expected to grow exponentially in the next decade. In this study, new and emerging applications of cell-free platforms, with a specific focus on cell-free protein synthesis (CFPS), will be examined. The current and near-future role of CFPS within metabolic engineering, prototyping, and biomanufacturing will be investigated as well as how the integration of machine learning is beneficial to these applications.
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Affiliation(s)
- August Brookwell
- Department of Chemistry & Biochemistry, College of Science & Mathematics, California Polytechnic State University, San Luis Obispo, CA 93407, USA;
| | - Javin P. Oza
- Department of Chemistry & Biochemistry, College of Science & Mathematics, California Polytechnic State University, San Luis Obispo, CA 93407, USA;
- Correspondence: (J.P.O.); (F.C.)
| | - Filippo Caschera
- Nuclera Nucleics Ltd., Cambridge CB4 0GD, UK
- Correspondence: (J.P.O.); (F.C.)
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42
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43
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Vink JNA, Baijens JHL, Brouns SJJ. PAM-repeat associations and spacer selection preferences in single and co-occurring CRISPR-Cas systems. Genome Biol 2021; 22:281. [PMID: 34593010 PMCID: PMC8482600 DOI: 10.1186/s13059-021-02495-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/09/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The adaptive CRISPR-Cas immune system stores sequences from past invaders as spacers in CRISPR arrays and thereby provides direct evidence that links invaders to hosts. Mapping CRISPR spacers has revealed many aspects of CRISPR-Cas biology, including target requirements such as the protospacer adjacent motif (PAM). However, studies have so far been limited by a low number of mapped spacers in the database. RESULTS By using vast metagenomic sequence databases, we map approximately one-third of more than 200,000 unique CRISPR spacers from a variety of microbes and derive a catalog of more than two hundred unique PAM sequences associated with specific CRISPR-Cas subtypes. These PAMs are further used to correctly assign the orientation of CRISPR arrays, revealing conserved patterns between the last nucleotides of the CRISPR repeat and PAM. We could also deduce CRISPR-Cas subtype-specific preferences for targeting either template or coding strand of open reading frames. While some DNA-targeting systems (type I-E and type II systems) prefer the template strand and avoid mRNA, other DNA- and RNA-targeting systems (types I-A and I-B and type III systems) prefer the coding strand and mRNA. In addition, we find large-scale evidence that both CRISPR-Cas adaptation machinery and CRISPR arrays are shared between different CRISPR-Cas systems. This could lead to simultaneous DNA and RNA targeting of invaders, which may be effective at combating mobile genetic invaders. CONCLUSIONS This study has broad implications for our understanding of how CRISPR-Cas systems work in a wide range of organisms for which only the genome sequence is known.
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Affiliation(s)
- Jochem N A Vink
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Jan H L Baijens
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands.
- Kavli Institute of Nanoscience, Delft, The Netherlands.
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44
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Lee KZ, Mechikoff MA, Kikla A, Liu A, Pandolfi P, Fitzgerald K, Gimble FS, Solomon KV. NgAgo possesses guided DNA nicking activity. Nucleic Acids Res 2021; 49:9926-9937. [PMID: 34478558 PMCID: PMC8464042 DOI: 10.1093/nar/gkab757] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 08/17/2021] [Accepted: 08/19/2021] [Indexed: 12/14/2022] Open
Abstract
Prokaryotic Argonautes (pAgos) have been proposed as more flexible tools for gene-editing as they do not require sequence motifs adjacent to their targets for function, unlike popular CRISPR/Cas systems. One promising pAgo candidate, from the halophilic archaeon Natronobacterium gregoryi (NgAgo), has been the subject of debate regarding its potential in eukaryotic systems. Here, we revisit this enzyme and characterize its function in prokaryotes. NgAgo expresses poorly in non-halophilic hosts with most of the protein being insoluble and inactive even after refolding. However, we report that the soluble fraction does indeed act as a nicking DNA endonuclease. NgAgo shares canonical domains with other catalytically active pAgos but also contains a previously unrecognized single-stranded DNA binding domain (repA). Both repA and the canonical PIWI domains participate in DNA cleavage activities of NgAgo. NgAgo can be programmed with guides to nick targeted DNA in Escherichia coli and in vitro 1 nt outside the 3' end of the guide sequence. We also found that these endonuclease activities are essential for enhanced NgAgo-guided homologous recombination, or gene-editing, in E. coli. Collectively, our results demonstrate the potential of NgAgo for gene-editing and provide new insight into seemingly contradictory reports.
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Affiliation(s)
- Kok Zhi Lee
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Michael A Mechikoff
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Archana Kikla
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47906, USA
| | - Arren Liu
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47906, USA
| | - Paula Pandolfi
- Department of Biological Sciences, Purdue University, West Lafayette, IN 47906, USA
| | - Kevin Fitzgerald
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47906, USA
| | - Frederick S Gimble
- Purdue University Interdisciplinary Life Science Program (PULSe), Purdue University, West Lafayette, IN 47906, USA.,Department of Biochemistry, Purdue University, West Lafayette, IN, 47906, USA
| | - Kevin V Solomon
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47906, USA.,Purdue University Interdisciplinary Life Science Program (PULSe), Purdue University, West Lafayette, IN 47906, USA
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45
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Lehr FX, Kuzembayeva A, Bailey ME, Kleindienst W, Kabisch J, Koeppl H. Functionalizing Cell-Free Systems with CRISPR-Associated Proteins: Application to RNA-Based Circuit Engineering. ACS Synth Biol 2021; 10:2138-2150. [PMID: 34383464 DOI: 10.1021/acssynbio.0c00386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cell-free systems have become a compelling choice for the prototyping of synthetic circuits. Many robust protocols for preparing cell-free systems are now available along with toolboxes designed for a variety of applications. Thus far, the production of cell-free extracts has often been decoupled from the production of functionalized proteins. Here, we leveraged a recent protocol for producing an E. coli-based cell-free expression system with two CRISPR-associated proteins, Csy4 and dCas9, expressed prior to harvest. We found that pre-expression did not affect the resulting extract performance, and the final concentrations of the endonucleases matched the level required for synthetic circuit prototyping. We demonstrated the benefits and versatility of dCas9 and Csy4 through the use of RNA circuitry based on a combination of single guide RNAs, small transcriptional activator RNAs, and toehold switches. For instance, we show that Csy4 processing increased 4-fold the dynamic range of a previously published AND-logic gate. Additionally, blending the CRISPR-enhanced extracts enabled us to reduce leakage in a multiple inputs gate, and to extend the type of Boolean functions available for RNA-based circuits, such as NAND-logic. Finally, we reported the use of simultaneous transcriptional and translational reporters in our RNA-based circuits. In particular, the AND-gate mRNA and protein levels were able to be independently monitored in response to transcriptional and translational activators. We hope this work will facilitate the adoption of advanced processing tools for RNA-based circuit prototyping in a cell-free environment.
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Affiliation(s)
- François-Xavier Lehr
- Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Darmstadt 64283, Germany
| | - Alina Kuzembayeva
- Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Darmstadt 64283, Germany
| | - Megan E Bailey
- Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Darmstadt 64283, Germany
| | - Werner Kleindienst
- Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
| | - Johannes Kabisch
- Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
| | - Heinz Koeppl
- Centre for Synthetic Biology, Technische Universität Darmstadt, Darmstadt 64287, Germany
- Department of Electrical Engineering and Information Technology, Technische Universität Darmstadt, Darmstadt 64283, Germany
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Ueno H, Sawada H, Soga N, Sano M, Nara S, Tabata KV, Su’etsugu M, Noji H. Amplification of over 100 kbp DNA from Single Template Molecules in Femtoliter Droplets. ACS Synth Biol 2021; 10:2179-2186. [PMID: 34406762 DOI: 10.1021/acssynbio.0c00584] [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: 11/28/2022]
Abstract
Reconstitution of the DNA amplification system in microcompartments is the primary step toward artificial cell construction through a bottom-up approach. However, amplification of >100 kbp DNA in micrometer-sized reactors has not yet been achieved. Here, implementing a fully reconstituted replisome of Escherichia coli in micrometer-sized water-in-oil droplets, we developed the in-droplet replication cycle reaction (RCR) system. For a 16 kbp template DNA, the in-droplet RCR system yielded positive RCR signals with a high success rate (82%) for the amplification from single molecule template DNA. The success rate for a 208 kbp template DNA was evidently lower (23%). This study establishes a platform for genome-sized DNA amplification from a single copy of template DNA with the potential to build more complex artificial cell systems comprising a large number of genes.
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Affiliation(s)
- Hiroshi Ueno
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Hiroki Sawada
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Naoki Soga
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Mio Sano
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Seia Nara
- Department of Life Science, College of Science, Rikkyo University, Tokyo 171-8501, Japan
| | - Kazuhito V. Tabata
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Masayuki Su’etsugu
- Department of Life Science, College of Science, Rikkyo University, Tokyo 171-8501, Japan
| | - Hiroyuki Noji
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
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Garenne D, Thompson S, Brisson A, Khakimzhan A, Noireaux V. The all-E. coliTXTL toolbox 3.0: new capabilities of a cell-free synthetic biology platform. Synth Biol (Oxf) 2021; 6:ysab017. [PMID: 34712841 PMCID: PMC8546610 DOI: 10.1093/synbio/ysab017] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 06/19/2021] [Accepted: 07/12/2021] [Indexed: 12/12/2022] Open
Abstract
The new generation of cell-free gene expression systems enables the prototyping and engineering of biological systems in vitro over a remarkable scope of applications and physical scales. As the utilization of DNA-directed in vitro protein synthesis expands in scope, developing more powerful cell-free transcription-translation (TXTL) platforms remains a major goal to either execute larger DNA programs or improve cell-free biomanufacturing capabilities. In this work, we report the capabilities of the all-E. coli TXTL toolbox 3.0, a multipurpose cell-free expression system specifically developed for synthetic biology. In non-fed batch-mode reactions, the synthesis of the fluorescent reporter protein eGFP (enhanced green fluorescent protein) reaches 4 mg/ml. In synthetic cells, consisting of liposomes loaded with a TXTL reaction, eGFP is produced at concentrations of >8 mg/ml when the chemical building blocks feeding the reaction diffuse through membrane channels to facilitate exchanges with the outer solution. The bacteriophage T7, encoded by a genome of 40 kb and ∼60 genes, is produced at a concentration of 1013 PFU/ml (plaque forming unit/ml). This TXTL system extends the current cell-free expression capabilities by offering unique strength and properties, for testing regulatory elements and circuits, biomanufacturing biologics or building synthetic cells.
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Affiliation(s)
- David Garenne
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Seth Thompson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Amaury Brisson
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Aset Khakimzhan
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, USA
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McSweeney MA, Styczynski MP. Effective Use of Linear DNA in Cell-Free Expression Systems. Front Bioeng Biotechnol 2021; 9:715328. [PMID: 34354989 PMCID: PMC8329657 DOI: 10.3389/fbioe.2021.715328] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/06/2021] [Indexed: 12/27/2022] Open
Abstract
Cell-free expression systems (CFEs) are cutting-edge research tools used in the investigation of biological phenomena and the engineering of novel biotechnologies. While CFEs have many benefits over in vivo protein synthesis, one particularly significant advantage is that CFEs allow for gene expression from both plasmid DNA and linear expression templates (LETs). This is an important and impactful advantage because functional LETs can be efficiently synthesized in vitro in a few hours without transformation and cloning, thus expediting genetic circuit prototyping and allowing expression of toxic genes that would be difficult to clone through standard approaches. However, native nucleases present in the crude bacterial lysate (the basis for the most affordable form of CFEs) quickly degrade LETs and limit expression yield. Motivated by the significant benefits of using LETs in lieu of plasmid templates, numerous methods to enhance their stability in lysate-based CFEs have been developed. This review describes approaches to LET stabilization used in CFEs, summarizes the advancements that have come from using LETs with these methods, and identifies future applications and development goals that are likely to be impactful to the field. Collectively, continued improvement of LET-based expression and other linear DNA tools in CFEs will help drive scientific discovery and enable a wide range of applications, from diagnostics to synthetic biology research tools.
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Affiliation(s)
- Megan A McSweeney
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, GA, United States
| | - Mark P Styczynski
- Georgia Institute of Technology, School of Chemical & Biomolecular Engineering, Atlanta, GA, United States
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Khakimzhan A, Garenne D, Tickman B, Fontana J, Carothers J, Noireaux V. Complex dependence of CRISPR-Cas9 binding strength on guide RNA spacer lengths. Phys Biol 2021; 18:056003. [PMID: 34102625 DOI: 10.1088/1478-3975/ac091e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 06/08/2021] [Indexed: 12/26/2022]
Abstract
It is established that for CRISPR-Cas9 applications guide RNAs with 17-20 bp long spacer sequences are optimal for accurate target binding and cleavage. In this work we perform cell-free CRISPRa (CRISPR activation) and CRISPRi (CRISPR inhibition) experiments to demonstrate the existence of a complex dependence of CRISPR-Cas9 binding as a function of the spacer length and complementarity. Our results show that significantly truncated or mismatched spacer sequences can form stronger guide-target bonds than the conventional 17-20 bp long spacers. To explain this phenomenon, we take into consideration previous structural and single-molecule CRISPR-Cas9 experiments and develop a novel thermodynamic model of CRISPR-Cas9 target recognition.
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Affiliation(s)
- Aset Khakimzhan
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN 55455, United States of America
| | - David Garenne
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN 55455, United States of America
| | - Benjamin Tickman
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA, 98195, United States of America
| | - Jason Fontana
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA, 98195, United States of America
| | - James Carothers
- Molecular Engineering & Sciences Institute, University of Washington, Seattle, WA, 98195, United States of America
- Department of Chemical Engineering, University of Washington, Seattle, WA, 98195, United States of America
- Center for Synthetic Biology, University of Washington, Seattle, WA, 98195, United States of America
| | - Vincent Noireaux
- School of Physics and Astronomy, University of Minnesota, 115 Union Street SE, Minneapolis, MN 55455, United States of America
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Abstract
Cell-free protein synthesis is a powerful tool to produce recombinant proteins, and as an open system, can often integrate all or part of downstream assays. Here we describe in vitro synthesis of the Streptococcus pyogenes type II-A CRISPR-Cas9 ribonucleoproteins (SpCas9 RNPs), consisting of the effector protein and the single guide RNAs (sgRNAs). In spite of its large molecular weight (160kDa), the SpCas9 effector is expressed relatively well from linear DNA templates under T7 promoter in commercial reconstituted cell-free protein synthesis systems. sgRNAs can be added before the effector synthesis reaction, or transcribed directly from linear DNA templates during the synthesis reaction. The newly synthesized SpCas9 effector forms an active RNP complex with sgRNAs. When a reconstituted cell-free system is used, the target DNA templates can also be added in the reactions, thereby combining CRISPR-Cas synthesis and activity assay.
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Affiliation(s)
- Colin McGaw
- Arbor Biotechnologies, Cambridge, MA, United States
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