1
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Feng W, Peng H, Zhang H, Weinfeld M, Le XC. A Sensitive Technique Unravels the Kinetics of Activation and Trans-Cleavage of CRISPR-Cas Systems. Angew Chem Int Ed Engl 2024; 63:e202404069. [PMID: 38526321 DOI: 10.1002/anie.202404069] [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] [Revised: 03/21/2024] [Accepted: 03/25/2024] [Indexed: 03/26/2024]
Abstract
Activation of the CRISPR-Cas13a system requires the formation of a crRNA-Cas13a ribonucleoprotein (RNP) complex and the binding of an RNA activator to the RNP. These two binding processes play a crucial role in the performance of the CRISPR-Cas13a system. However, the binding kinetics remain poorly understood, and a main challenge is the lack of a sensitive method for real-time measurements of the dynamically formed active CRISPR-Cas13a enzyme. We describe here a new method to study the binding kinetics and report the rate constants (kon and koff) and dissociation constant (Kd) for the binding between Cas13a and its activator. The method is able to unravel and quantify the kinetics of binding and cleavage separately, on the basis of measuring the real-time trans-cleavage rates of the CRISPR-Cas system and obtaining the real-time concentrations of the active CRISPR-Cas ternary complex. We further discovered that once activated, the Cas13a system operates at a wide range of temperatures (7-37 °C) with fast trans-cleavage kinetics. The new method and findings are important for diverse applications of the Cas13a system, such as the demonstrated quantification of microRNA at ambient temperatures (e.g., 25 °C).
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Affiliation(s)
- Wei Feng
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2G3, Canada
| | - Hanyong Peng
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2G3, Canada
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
| | - Hongquan Zhang
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2G3, Canada
| | - Michael Weinfeld
- Cross Cancer Institute and Department of Oncology, University of Alberta, Edmonton, Alberta, T6G 1Z2, Canada
| | - X Chris Le
- Division of Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, T6G 2G3, Canada
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2
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Hsiung CCS, Wilson CM, Sambold NA, Dai R, Chen Q, Teyssier N, Misiukiewicz S, Arab A, O'Loughlin T, Cofsky JC, Shi J, Gilbert LA. Engineered CRISPR-Cas12a for higher-order combinatorial chromatin perturbations. Nat Biotechnol 2024:10.1038/s41587-024-02224-0. [PMID: 38760567 DOI: 10.1038/s41587-024-02224-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/28/2024] [Indexed: 05/19/2024]
Abstract
Multiplexed genetic perturbations are critical for testing functional interactions among coding or non-coding genetic elements. Compared to double-stranded DNA cutting, repressive chromatin formation using CRISPR interference (CRISPRi) avoids genotoxicity and is more effective for perturbing non-coding regulatory elements in pooled assays. However, current CRISPRi pooled screening approaches are limited to targeting one to three genomic sites per cell. We engineer an Acidaminococcus Cas12a (AsCas12a) variant, multiplexed transcriptional interference AsCas12a (multiAsCas12a), that incorporates R1226A, a mutation that stabilizes the ribonucleoprotein-DNA complex via DNA nicking. The multiAsCas12a-KRAB fusion improves CRISPRi activity over DNase-dead AsCas12a-KRAB fusions, often rescuing the activities of lentivirally delivered CRISPR RNAs (crRNA) that are inactive when used with the latter. multiAsCas12a-KRAB supports CRISPRi using 6-plex crRNA arrays in high-throughput pooled screens. Using multiAsCas12a-KRAB, we discover enhancer elements and dissect the combinatorial function of cis-regulatory elements in human cells. These results instantiate a group testing framework for efficiently surveying numerous combinations of chromatin perturbations for biological discovery and engineering.
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Affiliation(s)
- C C-S Hsiung
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Urology, University of California, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Arc Institute, Palo Alto, CA, USA
| | - C M Wilson
- Department of Urology, University of California, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Arc Institute, Palo Alto, CA, USA
- Tetrad Graduate Program, University of California, San Francisco, CA, USA
| | | | - R Dai
- Department of Urology, University of California, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Arc Institute, Palo Alto, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - Q Chen
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - N Teyssier
- Biological and Medical Informatics Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - S Misiukiewicz
- Department of Urology, University of California, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
- Biomedical Sciences Graduate Program, University of California, San Francisco, San Francisco, CA, USA
| | - A Arab
- Arc Institute, Palo Alto, CA, USA
| | - T O'Loughlin
- Department of Urology, University of California, San Francisco, CA, USA
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA
| | - J C Cofsky
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - J Shi
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - L A Gilbert
- Department of Urology, University of California, San Francisco, CA, USA.
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA.
- Arc Institute, Palo Alto, CA, USA.
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3
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Bhattacharya S, Agarwal A, Muniyappa K. Deciphering the Substrate Specificity Reveals that CRISPR-Cas12a Is a Bifunctional Enzyme with Both Endo- and Exonuclease Activities. J Mol Biol 2024; 436:168550. [PMID: 38575054 DOI: 10.1016/j.jmb.2024.168550] [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: 10/18/2023] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/06/2024]
Abstract
The class 2 CRISPR-Cas9 and CRISPR-Cas12a systems, originally described as adaptive immune systems of bacteria and archaea, have emerged as versatile tools for genome-editing, with applications in biotechnology and medicine. However, significantly less is known about their substrate specificity, but such knowledge may provide instructive insights into their off-target cleavage and previously unrecognized mechanism of action. Here, we document that the Acidaminococcus sp. Cas12a (AsCas12a) binds preferentially, and independently of crRNA, to a suite of branched DNA structures, such as the Holliday junction (HJ), replication fork and D-loops, compared with single- or double-stranded DNA, and promotes their degradation. Further, our study revealed that AsCas12a binds to the HJ, specifically at the crossover region, protects it from DNase I cleavage and renders a pair of thymine residues in the HJ homologous core hypersensitive to KMnO4 oxidation, suggesting DNA melting and/or distortion. Notably, these structural changes enabled AsCas12a to resolve HJ into nonligatable intermediates, and subsequently their complete degradation. We further demonstrate that crRNA impedes HJ cleavage by AsCas12a, and that of Lachnospiraceae bacterium Cas12a, without affecting their DNA-binding ability. We identified a separation-of-function variant, which uncouples DNA-binding and DNA cleavage activities of AsCas12a. Importantly, we found robust evidence that AsCas12a endonuclease also has 3'-to-5' and 5'-to-3' exonuclease activity, and that these two activities synergistically promote degradation of DNA, yielding di- and mononucleotides. Collectively, this study significantly advances knowledge about the substrate specificity of AsCas12a and provides important insights into the degradation of different types of DNA substrates.
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Affiliation(s)
- Supreet Bhattacharya
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Ankit Agarwal
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Kalappa Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India.
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4
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Nalefski EA, Kooistra RM, Parikh I, Hedley S, Rajaraman K, Madan D. Determinants of CRISPR Cas12a nuclease activation by DNA and RNA targets. Nucleic Acids Res 2024; 52:4502-4522. [PMID: 38477377 PMCID: PMC11077072 DOI: 10.1093/nar/gkae152] [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: 05/31/2023] [Revised: 02/13/2024] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
The RNA-guided CRISPR-associated (Cas) enzyme Cas12a cleaves specific double-stranded (ds-) or single-stranded (ss-) DNA targets (in cis), unleashing non-specific ssDNA cleavage (in trans). Though this trans-activity is widely coopted for diagnostics, little is known about target determinants promoting optimal enzyme performance. Using quantitative kinetics, we show formation of activated nuclease proceeds via two steps whereby rapid binding of Cas12a ribonucleoprotein to target is followed by a slower allosteric transition. Activation does not require a canonical protospacer-adjacent motif (PAM), nor is utilization of such PAMs predictive of high trans-activity. We identify several target determinants that can profoundly impact activation times, including bases within the PAM (for ds- but not ssDNA targets) and sequences within and outside those complementary to the spacer, DNA topology, target length, presence of non-specific DNA, and ribose backbone itself, uncovering previously uncharacterized cleavage of and activation by RNA targets. The results provide insight into the mechanism of Cas12a activation, with direct implications on the role of Cas12a in bacterial immunity and for Cas-based diagnostics.
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Affiliation(s)
| | | | | | | | | | - Damian Madan
- Global Health Labs, Inc, Bellevue, WA 98007, USA
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5
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Sun K, Pu L, Chen C, Chen M, Li K, Li X, Li H, Geng J. An autocatalytic CRISPR-Cas amplification effect propelled by the LNA-modified split activators for DNA sensing. Nucleic Acids Res 2024; 52:e39. [PMID: 38477342 DOI: 10.1093/nar/gkae176] [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: 08/10/2023] [Revised: 01/25/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
CRISPR-Cas systems with dual functions offer precise sequence-based recognition and efficient catalytic cleavage of nucleic acids, making them highly promising in biosensing and diagnostic technologies. However, current methods encounter challenges of complexity, low turnover efficiency, and the necessity for sophisticated probe design. To better integrate the dual functions of Cas proteins, we proposed a novel approach called CRISPR-Cas Autocatalysis Amplification driven by LNA-modified Split Activators (CALSA) for the highly efficient detection of single-stranded DNA (ssDNA) and genomic DNA. By introducing split ssDNA activators and the site-directed trans-cleavage mediated by LNA modifications, an autocatalysis-driven positive feedback loop of nucleic acids based on the LbCas12a system was constructed. Consequently, CALSA enabled one-pot and real-time detection of genomic DNA and cell-free DNA (cfDNA) from different tumor cell lines. Notably, CALSA achieved high sensitivity, single-base specificity, and remarkably short reaction times. Due to the high programmability of nucleic acid circuits, these results highlighted the immense potential of CALSA as a powerful tool for cascade signal amplification. Moreover, the sensitivity and specificity further emphasized the value of CALSA in biosensing and diagnostics, opening avenues for future clinical applications.
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Affiliation(s)
- Ke Sun
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
- Tianfu Jincheng Laboratory, City of Future Medicine, Chengdu 641400, China
| | - Lei Pu
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
| | - Chuan Chen
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
- School of Pharmacy, North Sichuan Medical College, 637000 Nanchong, China
| | - Mutian Chen
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
| | - Kaiju Li
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
| | - Xinqiong Li
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
| | - Huanqing Li
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
| | - Jia Geng
- Department of Laboratory Medicine, State Key Laboratory of Biotherapy and Clinical Laboratory Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041 Chengdu, China
- Tianfu Jincheng Laboratory, City of Future Medicine, Chengdu 641400, China
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6
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Irmisch P, Mogila I, Samatanga B, Tamulaitis G, Seidel R. Retention of the RNA ends provides the molecular memory for maintaining the activation of the Csm complex. Nucleic Acids Res 2024; 52:3896-3910. [PMID: 38340341 DOI: 10.1093/nar/gkae080] [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: 11/02/2023] [Revised: 01/23/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
The type III CRISPR-Cas effector complex Csm functions as a molecular Swiss army knife that provides multilevel defense against foreign nucleic acids. The coordinated action of three catalytic activities of the Csm complex enables simultaneous degradation of the invader's RNA transcripts, destruction of the template DNA and synthesis of signaling molecules (cyclic oligoadenylates cAn) that activate auxiliary proteins to reinforce CRISPR-Cas defense. Here, we employed single-molecule techniques to connect the kinetics of RNA binding, dissociation, and DNA hydrolysis by the Csm complex from Streptococcus thermophilus. Although single-stranded RNA is cleaved rapidly (within seconds), dual-color FCS experiments and single-molecule TIRF microscopy revealed that Csm remains bound to terminal RNA cleavage products with a half-life of over 1 hour while releasing the internal RNA fragments quickly. Using a continuous fluorescent DNA degradation assay, we observed that RNA-regulated single-stranded DNase activity decreases on a similar timescale. These findings suggest that after fast target RNA cleavage the terminal RNA cleavage products stay bound within the Csm complex, keeping the Cas10 subunit activated for DNA destruction. Additionally, we demonstrate that during Cas10 activation, the complex remains capable of RNA turnover, i.e. of ongoing degradation of target RNA.
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Affiliation(s)
- Patrick Irmisch
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Irmantas Mogila
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Brighton Samatanga
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Gintautas Tamulaitis
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
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7
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Tian Z, Yan H, Zeng Y. Solid-Phase Extraction and Enhanced Amplification-Free Detection of Pathogens Integrated by Multifunctional CRISPR-Cas12a. ACS APPLIED MATERIALS & INTERFACES 2024; 16:14445-14456. [PMID: 38472096 DOI: 10.1021/acsami.3c17039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Public healthcare demands effective and pragmatic diagnostic tools to address the escalating challenges in infection management in resource-limited areas. Recent advances in clustered regularly interspaced short palindromic repeat (CRISPR)-based biosensing promise the development of next-generation tools for disease diagnostics, including point-of-care (POC) testing for infectious diseases. The currently prevailing strategy of developing CRISPR/Cas-based diagnostics exploits only the target identification and trans-cleavage activity of a CRISPR-Cas12a/Cas13a system to provide diagnostic results, and they need to be combined with an additional preamplification reaction to enhance sensitivity. In contrast to this dual-function strategy, here, we present a new approach that collaboratively integrates the triple functions of CRISPR-Cas12a: target identification, sequence-specific enrichment, and signal generation. With this approach, we develop a nucleic acid assay termed Solid-Phase Extraction and Enhanced Detection Assay integrated by CRISPR-Cas12a (SPEEDi-CRISPR) that negates the need for preamplification but significantly improves the detection of limit (LOD) from the pM to fM level. Specifically, using Cas12a-coated magnetic beads, this assay combines efficient solid-phase extraction and enrichment of DNA targets enabled by the sequence-specific affinity of CRISPR-Cas12a with fluorogenic detection by activated Cas12a on beads. SPEEDi-CRISPR, for the first time, leverages the possibility of employing CRISPR/Cas12a in nucleic acid extraction and integrates the ability of both enrichment and detection of CRISPR/Cas into a single platform. Our proof-of-concept studies revealed that the SPEEDi-CRISPR assay has great specificity to distinguish HPV-18 from HPV-16, and Parvovirus B19, in addition to being able to detect HPV-18 at a concentration as low as 2.3 fM in 100 min and 4.7 fM in 60 min. Furthermore, we proved that this assay can be coupled with two point-of-care testing strategies: the smartphone-based fluorescence detector and the lateral flow assay. Overall, these results suggested that our assay could pave a new way for developing CRISPR diagnostics.
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Affiliation(s)
- Zimu Tian
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - He Yan
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Yong Zeng
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida 32611, United States
- University of Florida Health Cancer Center, Gainesville, Florida 32611, United States
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8
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Karneyeva K, Kolesnik M, Livenskyi A, Zgoda V, Zubarev V, Trofimova A, Artamonova D, Ispolatov Y, Severinov K. Interference Requirements of Type III CRISPR-Cas Systems from Thermus thermophilus. J Mol Biol 2024; 436:168448. [PMID: 38266982 DOI: 10.1016/j.jmb.2024.168448] [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: 09/02/2023] [Revised: 01/12/2024] [Accepted: 01/13/2024] [Indexed: 01/26/2024]
Abstract
Among the diverse prokaryotic adaptive immunity mechanisms, the Type III CRISPR-Cas systems are the most complex. The multisubunit Type III effectors recognize RNA targets complementary to CRISPR RNAs (crRNAs). Target recognition causes synthesis of cyclic oligoadenylates that activate downstream auxiliary effectors, which affect cell physiology in complex and poorly understood ways. Here, we studied the ability of III-A and III-B CRISPR-Cas subtypes from Thermus thermophilus to interfere with plasmid transformation. We find that for both systems, requirements for crRNA-target complementarity sufficient for interference depend on the target transcript abundance, with more abundant targets requiring shorter complementarity segments. This result and thermodynamic calculations indicate that Type III effectors bind their targets in a simple bimolecular reaction with more extensive crRNA-target base pairing compensating for lower target abundance. Since the targeted RNA used in our work is non-essential for either the host or the plasmid, the results also establish that a certain number of target-bound effector complexes must be present in the cell to interfere with plasmid establishment. For the more active III-A system, we determine the minimal length of RNA-duplex sufficient for interference and show that the position of this minimal duplex can vary within the effector. Finally, we show that the III-A immunity is dependent on the HD nuclease domain of the Cas10 subunit. Since this domain is absent from the III-B system the result implies that the T. thermophilus III-B system must elicit a more efficient cyclic oligoadenylate-dependent response to provide the immunity.
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Affiliation(s)
- Karyna Karneyeva
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Matvey Kolesnik
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Alexei Livenskyi
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Viktor Zgoda
- Institute of Biomedical Chemistry, Moscow 119435, Russia
| | - Vasiliy Zubarev
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Anna Trofimova
- Laboratory of Molecular Genetics of Microorganisms, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Daria Artamonova
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Yaroslav Ispolatov
- Departamento de Física, Center for Interdisciplinary Research in Astrophysics and Space Science, Universidad de Santiago de Chile, Victor Jara 3493, Santiago, Chile
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9
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Clark T, Waller MA, Loo L, Moreno CL, Denes CE, Neely GG. CRISPR activation screens: navigating technologies and applications. Trends Biotechnol 2024:S0167-7799(24)00036-2. [PMID: 38493051 DOI: 10.1016/j.tibtech.2024.02.007] [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: 11/20/2023] [Revised: 02/06/2024] [Accepted: 02/06/2024] [Indexed: 03/18/2024]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) activation (CRISPRa) has become an integral part of the molecular biology toolkit. CRISPRa genetic screens are an exciting high-throughput means of identifying genes the upregulation of which is sufficient to elicit a given phenotype. Activation machinery is continually under development to achieve greater, more robust, and more consistent activation. In this review, we offer a succinct technological overview of available CRISPRa architectures and a comprehensive summary of pooled CRISPRa screens. Furthermore, we discuss contemporary applications of CRISPRa across broad fields of research, with the aim of presenting a view of exciting emerging applications for CRISPRa screening.
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Affiliation(s)
- Teleri Clark
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, and School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Matthew A Waller
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, and School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Lipin Loo
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, and School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Cesar L Moreno
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, and School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - Christopher E Denes
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, and School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia
| | - G Gregory Neely
- Charles Perkins Centre, Dr. John and Anne Chong Lab for Functional Genomics, and School of Life and Environmental Sciences, University of Sydney, Camperdown, New South Wales, Australia.
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10
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Li X, Dang Z, Tang W, Zhang H, Shao J, Jiang R, Zhang X, Huang F. Detection of Parasites in the Field: The Ever-Innovating CRISPR/Cas12a. BIOSENSORS 2024; 14:145. [PMID: 38534252 DOI: 10.3390/bios14030145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/11/2024] [Accepted: 03/12/2024] [Indexed: 03/28/2024]
Abstract
The rapid and accurate identification of parasites is crucial for prompt therapeutic intervention in parasitosis and effective epidemiological surveillance. For accurate and effective clinical diagnosis, it is imperative to develop a nucleic-acid-based diagnostic tool that combines the sensitivity and specificity of nucleic acid amplification tests (NAATs) with the speed, cost-effectiveness, and convenience of isothermal amplification methods. A new nucleic acid detection method, utilizing the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) nuclease, holds promise in point-of-care testing (POCT). CRISPR/Cas12a is presently employed for the detection of Plasmodium falciparum, Toxoplasma gondii, Schistosoma haematobium, and other parasites in blood, urine, or feces. Compared to traditional assays, the CRISPR assay has demonstrated notable advantages, including comparable sensitivity and specificity, simple observation of reaction results, easy and stable transportation conditions, and low equipment dependence. However, a common issue arises as both amplification and cis-cleavage compete in one-pot assays, leading to an extended reaction time. The use of suboptimal crRNA, light-activated crRNA, and spatial separation can potentially weaken or entirely eliminate the competition between amplification and cis-cleavage. This could lead to enhanced sensitivity and reduced reaction times in one-pot assays. Nevertheless, higher costs and complex pre-test genome extraction have hindered the popularization of CRISPR/Cas12a in POCT.
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Affiliation(s)
- Xin Li
- School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Zhisheng Dang
- National Institute of Parasitic Diseases, Chinese Center for Diseases Control and Prevention (Chinese Center for Tropical Diseases Research), Key Laboratory of Parasite and Vector Biology, National Health Commission of the People's Republic of China (NHC), World Health Organization (WHO) Collaborating Center for Tropical Diseases, National Center for International Research on Tropical Diseases, Shanghai 200025, China
| | - Wenqiang Tang
- State Key Laboratory of Hulless Barley and Yak Germplasm Resources and Genetic Improvement, Lhasa 850002, China
- Tibet Academy of Agriculture and Animal Husbandry Sciences, Lhasa 850002, China
| | - Haoji Zhang
- School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Jianwei Shao
- School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Rui Jiang
- College of Animal Science and Veterinary Medicine, Huazhong Agricultural University, Wuhan 430070, China
| | - Xu Zhang
- School of Life Science and Engineering, Foshan University, Foshan 528225, China
| | - Fuqiang Huang
- School of Life Science and Engineering, Foshan University, Foshan 528225, China
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11
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Saha A, Ahsan M, Arantes PR, Schmitz M, Chanez C, Jinek M, Palermo G. An alpha-helical lid guides the target DNA toward catalysis in CRISPR-Cas12a. Nat Commun 2024; 15:1473. [PMID: 38368461 PMCID: PMC10874386 DOI: 10.1038/s41467-024-45762-6] [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: 03/07/2023] [Accepted: 02/01/2024] [Indexed: 02/19/2024] Open
Abstract
CRISPR-Cas12a is a powerful RNA-guided genome-editing system that generates double-strand DNA breaks using its single RuvC nuclease domain by a sequential mechanism in which initial cleavage of the non-target strand is followed by target strand cleavage. How the spatially distant DNA target strand traverses toward the RuvC catalytic core is presently not understood. Here, continuous tens of microsecond-long molecular dynamics and free-energy simulations reveal that an α-helical lid, located within the RuvC domain, plays a pivotal role in the traversal of the DNA target strand by anchoring the crRNA:target strand duplex and guiding the target strand toward the RuvC core, as also corroborated by DNA cleavage experiments. In this mechanism, the REC2 domain pushes the crRNA:target strand duplex toward the core of the enzyme, while the Nuc domain aids the bending and accommodation of the target strand within the RuvC core by bending inward. Understanding of this critical process underlying Cas12a activity will enrich fundamental knowledge and facilitate further engineering strategies for genome editing.
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Affiliation(s)
- Aakash Saha
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA
| | - Mohd Ahsan
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA
| | - Pablo R Arantes
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA
| | - Michael Schmitz
- Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Christelle Chanez
- Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zürich, Winterthurerstrasse 190, CH-8057, Zürich, Switzerland
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA.
- Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, USA.
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12
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Fu X, Sun J, Yu B, Ye Y, Sheng L, Ji J, Zheng J, Fan M, Shao J, Sun X. Investigating enzyme kinetics and fluorescence sensing strategy of CRISPR/Cas12a for foodborne pathogenic bacteria. Anal Chim Acta 2024; 1290:342203. [PMID: 38246741 DOI: 10.1016/j.aca.2024.342203] [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: 10/29/2023] [Revised: 12/10/2023] [Accepted: 01/01/2024] [Indexed: 01/23/2024]
Abstract
Foodborne pathogenic bacteria are widespread in various foods, whose cross-contamination and re-contamination are critical influences on food safety. Rapid, accurate, and sensitive detection of foodborne pathogenic bacteria remains a topic of concern. CRISPR/Cas12a can recognize double-stranded DNA directly, showing great potential in nucleic acid detection. However, few studies have investigated the cleavage properties of CRISPR/Cas12a. In this study, the trans-cleavage properties of LbCas12a and AsCas12a were investigated to construct the detection methods for foodborne pathogenic bacteria. The highly sensitive fluorescent strategies for foodborne pathogens were constructed by analyzing the cleavage rates and properties of substrates at different substrate concentrations. Cas12a was activated in the presence of foodborne pathogenic target sequence was present, resulting in the cleavage of a single-stranded reporter ssDNA co-labelled by fluorescein quencher and fluorescein. The sensitivity and specificity of the Cas12a fluorescent strategy was investigated with Salmonella and Staphylococcus aureus as examples. The results showed that AsCas12a was slightly more capable of trans-cleavage than LbCas12a. The detection limits of AsCas12a for Salmonella and Staphylococcus aureus were 24.9 CFU mL-1 and 1.50 CFU mL-1, respectively. In all the seven bacteria, Staphylococcus aureus and Salmonella were accurately discriminated. The study provided a basis for constructing and improving the CRISPR/Cas12a fluorescence strategies. The AsCas12a-based detection strategy is expected to be a promising method for field detection.
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Affiliation(s)
- XuRan Fu
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - JiaDi Sun
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China.
| | - Bingqian Yu
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China
| | - Yongli Ye
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - Lina Sheng
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - Jian Ji
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China
| | - Jiayu Zheng
- Product Quality Comprehensive Inspection and Testing Center, Baoying, Jiangsu, 225800, PR China
| | - Minghong Fan
- Product Quality Comprehensive Inspection and Testing Center, Baoying, Jiangsu, 225800, PR China
| | - Jingdong Shao
- Comprehensive Technology Center of Zhangjiagang Customs, Zhangjiagang, Jiangsu, 215600, PR China
| | - XiuLan Sun
- School of Food Science and Technology, International Joint Laboratory on Food Safety, Synergetic Innovation Center of Food Safety and Quality Control, Jiangnan University, Wuxi, Jiangsu, 214122, PR China; Yixing Institute of Food and Biotechnology Co., Ltd, Yixing, 214200, PR China.
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13
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Hsiung CC, Wilson CM, Sambold NA, Dai R, Chen Q, Misiukiewicz S, Arab A, Teyssier N, O'Loughlin T, Cofsky JC, Shi J, Gilbert LA. Higher-order combinatorial chromatin perturbations by engineered CRISPR-Cas12a for functional genomics. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.18.558350. [PMID: 37781594 PMCID: PMC10541102 DOI: 10.1101/2023.09.18.558350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
Multiplexed genetic perturbations are critical for testing functional interactions among coding or non-coding genetic elements. Compared to double-stranded DNA cutting, repressive chromatin formation using CRISPR interference (CRISPRi) avoids genotoxicity and is more effective for perturbing non-coding regulatory elements in pooled assays. However, current CRISPRi pooled screening approaches are limited to targeting 1-3 genomic sites per cell. To develop a tool for higher-order ( > 3) combinatorial targeting of genomic sites with CRISPRi in functional genomics screens, we engineered an Acidaminococcus Cas12a variant -- referred to as mul tiplexed transcriptional interference AsCas12a (multiAsCas12a). multiAsCas12a incorporates a key mutation, R1226A, motivated by the hypothesis of nicking-induced stabilization of the ribonucleoprotein:DNA complex for improving CRISPRi activity. multiAsCas12a significantly outperforms prior state-of-the-art Cas12a variants in combinatorial CRISPRi targeting using high-order multiplexed arrays of lentivirally transduced CRISPR RNAs (crRNA), including in high-throughput pooled screens using 6-plex crRNA array libraries. Using multiAsCas12a CRISPRi, we discover new enhancer elements and dissect the combinatorial function of cis-regulatory elements. These results instantiate a group testing framework for efficiently surveying potentially numerous combinations of chromatin perturbations for biological discovery and engineering.
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14
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Shigemori H, Fujita S, Tamiya E, Nagai H. Miniaturization of CRISPR/Cas12-Based DNA Sensor Array by Non-Contact Printing. MICROMACHINES 2024; 15:144. [PMID: 38258263 PMCID: PMC10818962 DOI: 10.3390/mi15010144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024]
Abstract
DNA microarrays have been applied for comprehensive genotyping, but remain a drawback in complicated operations. As a solution, we previously reported the solid-phase collateral cleavage (SPCC) system based on the clustered regularly interspaced short palindromic repeat/CRISPR-associated protein 12 (CRISPR/Cas12). Surface-immobilized Cas12-CRISPR RNA (crRNA) can directly hybridize target double-stranded DNA (dsDNA) and subsequently produce a signal via the cleavage of single-stranded DNA (ssDNA) reporter immobilized on the same spot. Therefore, SPCC-based multiplex dsDNA detection can be performed easily. This study reports the miniaturization of SPCC-based spots patterned by a non-contact printer and its performance in comprehensive genotyping on a massively accumulated array. Initially, printing, immobilization, and washing processes of Cas12-crRNA were established to fabricate the non-contact-patterned SPCC-based sensor array. A target dsDNA concentration response was obtained based on the developed sensor array, even with a spot diameter of 0.64 ± 0.05 mm. Also, the limit of detection was 572 pM, 531 pM, and 3.04 nM with 40, 20, and 10 nL-printing of Cas12-crRNA, respectively. Furthermore, the sensor array specifically detected three dsDNA sequences in one-pot multiplexing; therefore, the feasibility of comprehensive genotyping was confirmed. These results demonstrate that our technology can be miniaturized as a CRISPR/Cas12-based microarray by using non-contact printing. In the future, the non-contact-patterned SPCC-based sensor array can be applied as an alternative tool to DNA microarrays.
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Affiliation(s)
- Hiroki Shigemori
- Advanced Photonics and Biosensing Open Innovation Laboratory (PhotoBIO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Photonics Center Osaka University, 2-1 Yamada-Oka, Suita 565-0871, Osaka, Japan; (H.S.); (S.F.); (E.T.)
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-ku, Kobe 657-0011, Hyogo, Japan
| | - Satoshi Fujita
- Advanced Photonics and Biosensing Open Innovation Laboratory (PhotoBIO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Photonics Center Osaka University, 2-1 Yamada-Oka, Suita 565-0871, Osaka, Japan; (H.S.); (S.F.); (E.T.)
| | - Eiichi Tamiya
- Advanced Photonics and Biosensing Open Innovation Laboratory (PhotoBIO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Photonics Center Osaka University, 2-1 Yamada-Oka, Suita 565-0871, Osaka, Japan; (H.S.); (S.F.); (E.T.)
- Institute of Scientific and Industrial Research (SANKEN), Osaka University, 8-1 Mihogaoka, Ibaraki 567-0047, Osaka, Japan
| | - Hidenori Nagai
- Advanced Photonics and Biosensing Open Innovation Laboratory (PhotoBIO-OIL), National Institute of Advanced Industrial Science and Technology (AIST), Photonics Center Osaka University, 2-1 Yamada-Oka, Suita 565-0871, Osaka, Japan; (H.S.); (S.F.); (E.T.)
- Graduate School of Human Development and Environment, Kobe University, 3-11 Tsurukabuto, Nada-ku, Kobe 657-0011, Hyogo, Japan
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15
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Nguyen GT, Schelling MA, Buscher KA, Sritharan A, Sashital DG. CRISPR-Cas12a exhibits metal-dependent specificity switching. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.29.569287. [PMID: 38076861 PMCID: PMC10705449 DOI: 10.1101/2023.11.29.569287] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Cas12a is the immune effector of type V-A CRISPR-Cas systems and has been co-opted for genome editing and other biotechnology tools. The specificity of Cas12a has been the subject of extensive investigation both in vitro and in genome editing experiments. However, in vitro studies have often been performed at high magnesium ion concentrations that are inconsistent with the free Mg2+ concentrations that would be present in cells. By profiling the specificity of Cas12a orthologs at a range of Mg2+ concentrations, we find that Cas12a switches its specificity depending on metal ion concentration. Lowering Mg2+ concentration decreases cleavage defects caused by seed mismatches, while increasing the defects caused by PAM-distal mismatches. We show that Cas12a can bind seed mutant targets more rapidly at low Mg2+ concentrations, resulting in faster cleavage. In contrast, PAM-distal mismatches cause substantial defects in cleavage following formation of the Cas12a-target complex at low Mg2+ concentrations. We observe differences in Cas12a specificity switching between three orthologs that results in variations in the routes of phage escape from Cas12a-mediated immunity. Overall, our results reveal the importance of physiological metal ion conditions on the specificity of Cas effectors that are used in different cellular environments.
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Affiliation(s)
- Giang T. Nguyen
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
- Equal contribution
| | - Michael A. Schelling
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
- Equal contribution
| | - Kathryn A. Buscher
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
- Current address: Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Aneisha Sritharan
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
- Current address: Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Dipali G. Sashital
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
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16
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Gao S, Guan H, Bloomer H, Wich D, Song D, Khirallah J, Ye Z, Zhao Y, Chen M, Xu C, Liu L, Xu Q. Harnessing non-Watson-Crick's base pairing to enhance CRISPR effectors cleavage activities and enable gene editing in mammalian cells. Proc Natl Acad Sci U S A 2024; 121:e2308415120. [PMID: 38150477 PMCID: PMC10786293 DOI: 10.1073/pnas.2308415120] [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: 05/19/2023] [Accepted: 11/21/2023] [Indexed: 12/29/2023] Open
Abstract
Genomic DNA of the cyanophage S-2L virus is composed of 2-aminoadenine (Z), thymine (T), guanine (G), and cytosine (C), forming the genetic alphabet ZTGC, which violates Watson-Crick base pairing rules. The Z-base has an extra amino group on the two position that allows the formation of a third hydrogen bond with thymine in DNA strands. Here, we explored and expanded applications of this non-Watson-Crick base pairing in protein expression and gene editing. Both ZTGC-DNA (Z-DNA) and ZUGC-RNA (Z-RNA) produced in vitro show detectable compatibility and can be decoded in mammalian cells, including Homo sapiens cells. Z-crRNA can guide CRISPR-effectors SpCas9 and LbCas12a to cleave specific DNA through non-Watson-Crick base pairing and boost cleavage activities compared to A-crRNA. Z-crRNA can also allow for efficient gene and base editing in human cells. Together, our results help pave the way for potential strategies for optimizing DNA or RNA payloads for gene editing therapeutics and give insights to understanding the natural Z-DNA genome.
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Affiliation(s)
- Shuliang Gao
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Huiwen Guan
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Hanan Bloomer
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Douglas Wich
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Donghui Song
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Jennifer Khirallah
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Zhongfeng Ye
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Yu Zhao
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Mengting Chen
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Chutian Xu
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Lihan Liu
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
| | - Qiaobing Xu
- Department of Biomedical Engineering, Tufts University, Medford, MA02155
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17
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Badon IW, Oh Y, Kim HJ, Lee SH. Recent application of CRISPR-Cas12 and OMEGA system for genome editing. Mol Ther 2024; 32:32-43. [PMID: 37952084 PMCID: PMC10787141 DOI: 10.1016/j.ymthe.2023.11.013] [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: 09/11/2023] [Revised: 10/27/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023] Open
Abstract
In 2012, it was discovered that precise gene editing could be induced in target DNA using the reprogrammable characteristics of the CRISPR system. Since then, several studies have investigated the potential of the CRISPR system to edit various biological organisms. For the typical CRISPR system obtained from bacteria and archaea, many application studies have been conducted and have spread to various fields. To date, orthologs with various characteristics other than CRISPR-Cas9 have been discovered and are being intensively studied in the field of gene editing. CRISPR-Cas12 and its varied orthologs are representative examples of genome editing tools and have superior properties in terms of in vivo target gene editing compared with Cas9. Recently, TnpB and Fanzor of the OMEGA (obligate mobile element guided activity) system were identified to be the ancestor of CRISPR-Cas12 on the basis of phylogenetic analysis. Notably, the compact sizes of Cas12 and OMEGA endonucleases allow adeno-associated virus (AAV) delivery; hence, they are set to challenge Cas9 for in vivo gene therapy. This review is focused on these RNA-guided reprogrammable endonucleases: their structure, biochemistry, off-target effects, and applications in therapeutic gene editing.
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Affiliation(s)
- Isabel Wen Badon
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Yeounsun Oh
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Ho-Joong Kim
- Department of Chemistry, Chosun University, Gwangju 61452, Republic of Korea.
| | - Seung Hwan Lee
- Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea.
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18
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Lee Y, Oh Y, Lee SH. Recent advances in genome engineering by CRISPR technology. BMB Rep 2024; 57:12-18. [PMID: 38053294 PMCID: PMC10828434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 09/19/2023] [Accepted: 09/27/2023] [Indexed: 12/07/2023] Open
Abstract
Due to the development of CRISPR technology, the era of effective editing of target genes has arrived. However, the offtarget problem that occurs when recognizing target DNA due to the inherent nature of CRISPR components remains the biggest task to be overcome in the future. In this review, the principle of inducing such unintended off-target editing is analyzed from the structural aspect of CRISPR, and the methodology that has been developed to reduce off-target editing until now is summarized. [BMB Reports 2024; 57(1): 12-18].
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Affiliation(s)
- Youngsik Lee
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Yeounsun Oh
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
| | - Seung Hwan Lee
- Department of Life Science, Chung-Ang University, Seoul 06974, Korea
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19
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Yan H, Wen Y, Tian Z, Hart N, Han S, Hughes SJ, Zeng Y. A one-pot isothermal Cas12-based assay for the sensitive detection of microRNAs. Nat Biomed Eng 2023; 7:1583-1601. [PMID: 37106152 PMCID: PMC11108682 DOI: 10.1038/s41551-023-01033-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 03/29/2023] [Indexed: 04/29/2023]
Abstract
The use of microRNAs as clinical cancer biomarkers is hindered by the absence of accurate, fast and inexpensive assays for their detection in biofluids. Here we report a one-step and one-pot isothermal assay that leverages rolling-circle amplification and the endonuclease Cas12a for the accurate detection of specific miRNAs. The assay exploits the cis-cleavage activity of Cas12a to enable exponential rolling-circle amplification of target sequences and its trans-cleavage activity for their detection and for signal amplification. In plasma from patients with pancreatic ductal adenocarcinoma, the assay detected the miRNAs miR-21, miR-196a, miR-451a and miR-1246 in extracellular vesicles at single-digit femtomolar concentrations with single-nucleotide specificity. The assay is rapid (sample-to-answer times ranged from 20 min to 3 h), does not require specialized instrumentation and is compatible with a smartphone-based fluorescence detection and with the lateral-flow format for visual readouts. Simple assays for the detection of miRNAs in blood may aid the development of miRNAs as biomarkers for the diagnosis and prognosis of cancers.
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Affiliation(s)
- He Yan
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Yunjie Wen
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Zimu Tian
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Nathan Hart
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Song Han
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Steven J Hughes
- Department of Surgery, University of Florida College of Medicine, Gainesville, FL, USA
| | - Yong Zeng
- Department of Chemistry, University of Florida, Gainesville, FL, USA.
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA.
- University of Florida Health Cancer Center, Gainesville, FL, USA.
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20
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Chen H, Zhou T, Li S, Feng J, Li W, Li L, Zhou X, Wang M, Li F, Zhao X, Ren L. Living Magnetotactic Microrobots Based on Bacteria with a Surface-Displayed CRISPR/Cas12a System for Penaeus Viruses Detection. ACS APPLIED MATERIALS & INTERFACES 2023; 15:47930-47938. [PMID: 37811735 DOI: 10.1021/acsami.3c09690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Bacterial microrobots are an emerging living material in the field of diagnostics. However, it is an important challenge to make bacterial microrobots with both controlled motility and specific functions. Herein, magnetically driven diagnostic bacterial microrobots are prepared by standardized and modular synthetic biology methods. To ensure mobility, the Mms6 protein is displayed on the surface of bacteria and is exploited for magnetic biomineralization. This gives the bacterial microrobot the ability to cruise flexibly and rapidly with a magnetization intensity up to about 18.65 emu g-1. To achieve the diagnostic function, the Cas12a protein is displayed on the bacterial surface and is used for aquatic pathogen nucleic acid detection. This allows the bacterial microrobot to achieve sensitive, rapid, and accurate on-site nucleic acid detection, with detection limits of 8 copies μL-1 for decapod iridescent virus 1 (DIV1) and 7 copies μL-1 for white spot syndrome virus (WSSV). In particular, the diagnostic results based on the bacterial microrobots remained consistent with the gold standard test results when tested on shrimp tissue. This approach is a flexible and customizable strategy for building bacterial microrobots, providing a reliable and versatile solution for the design of bacterial microrobots.
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Affiliation(s)
- Haoxiang Chen
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Tao Zhou
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Shuo Li
- College of Life Science and Medicine, Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Junya Feng
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Wenlong Li
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Lihuang Li
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Xi Zhou
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Miao Wang
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
| | - Fang Li
- Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, Ministry of Natural Resources, Xiamen 361005, P. R. China
| | - Xueqin Zhao
- College of Life Science and Medicine, Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Sci-Tech University, Hangzhou 310018, P. R. China
| | - Lei Ren
- Department of Biomaterials, The Higher Educational Key Laboratory for Biomedical Engineering of Fujian Province, Research Center of Biomedical Engineering of Xiamen, College of Materials, Xiamen University, Xiamen 361005, P. R. China
- State Key Lab of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, P. R. China
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21
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Singh J, Liu KG, Allen A, Jiang W, Qin PZ. A DNA unwinding equilibrium serves as a checkpoint for CRISPR-Cas12a target discrimination. Nucleic Acids Res 2023; 51:8730-8743. [PMID: 37522352 PMCID: PMC10484686 DOI: 10.1093/nar/gkad636] [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: 05/16/2023] [Revised: 07/12/2023] [Accepted: 07/18/2023] [Indexed: 08/01/2023] Open
Abstract
CRISPR-associated proteins such as Cas9 and Cas12a are programable RNA-guided nucleases that have emerged as powerful tools for genome manipulation and molecular diagnostics. However, these enzymes are prone to cleaving off-target sequences that contain mismatches between the RNA guide and DNA protospacer. In comparison to Cas9, Cas12a has demonstrated distinct sensitivity to protospacer-adjacent-motif (PAM) distal mismatches, and the molecular basis of Cas12a's enhanced target discrimination is of great interest. In this study, we investigated the mechanism of Cas12a target recognition using a combination of site-directed spin labeling, fluorescent spectroscopy, and enzyme kinetics. With a fully matched RNA guide, the data revealed an inherent equilibrium between a DNA unwound state and a DNA-paired duplex-like state. Experiments with off-target RNA guides and pre-nicked DNA substrates identified the PAM-distal DNA unwinding equilibrium as a mismatch sensing checkpoint prior to the first step of DNA cleavage. The finding sheds light on the distinct targeting mechanism of Cas12a and may better inform CRISPR based biotechnology developments.
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Affiliation(s)
- Jaideep Singh
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Kevin G Liu
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Aleique Allen
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Wei Jiang
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
| | - Peter Z Qin
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA
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22
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Rananaware SR, Vesco EK, Shoemaker GM, Anekar SS, Sandoval LSW, Meister KS, Macaluso NC, Nguyen LT, Jain PK. Programmable RNA detection with CRISPR-Cas12a. Nat Commun 2023; 14:5409. [PMID: 37669948 PMCID: PMC10480431 DOI: 10.1038/s41467-023-41006-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/21/2023] [Indexed: 09/07/2023] Open
Abstract
Cas12a, a CRISPR-associated protein complex, has an inherent ability to cleave DNA substrates and is utilized in diagnostic tools to identify DNA molecules. We demonstrate that multiple orthologs of Cas12a activate trans-cleavage in the presence of split activators. Specifically, the PAM-distal region of the crRNA recognizes RNA targets provided that the PAM-proximal seed region has a DNA target. Our method, Split Activator for Highly Accessible RNA Analysis (SAHARA), detects picomolar concentrations of RNA without sample amplification, reverse-transcription, or strand-displacement by simply supplying a short DNA sequence complementary to the seed region. Beyond RNA detection, SAHARA outperforms wild-type CRISPR-Cas12a in specificity towards point-mutations and can detect multiple RNA and DNA targets in pooled crRNA/Cas12a arrays via distinct PAM-proximal seed DNAs. In conclusion, SAHARA is a simple, yet powerful nucleic acid detection platform based on Cas12a that can be applied in a multiplexed fashion and potentially be expanded to other CRISPR-Cas enzymes.
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Affiliation(s)
| | - Emma K Vesco
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Grace M Shoemaker
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Swapnil S Anekar
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | | | - Katelyn S Meister
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Nicolas C Macaluso
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Long T Nguyen
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Piyush K Jain
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA.
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, FL, USA.
- UF Health Cancer Center, University of Florida, Gainesville, FL, USA.
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23
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Huang S, Dai R, Zhang Z, Zhang H, Zhang M, Li Z, Zhao K, Xiong W, Cheng S, Wang B, Wan Y. CRISPR/Cas-Based Techniques for Live-Cell Imaging and Bioanalysis. Int J Mol Sci 2023; 24:13447. [PMID: 37686249 PMCID: PMC10487896 DOI: 10.3390/ijms241713447] [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: 07/21/2023] [Revised: 08/09/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
CRISPR/Cas systems have found widespread applications in gene editing due to their high accuracy, high programmability, ease of use, and affordability. Benefiting from the cleavage properties (trans- or cis-) of Cas enzymes, the scope of CRISPR/Cas systems has expanded beyond gene editing and they have been utilized in various fields, particularly in live-cell imaging and bioanalysis. In this review, we summarize some fundamental working mechanisms and concepts of the CRISPR/Cas systems, describe the recent advances and design principles of CRISPR/Cas mediated techniques employed in live-cell imaging and bioanalysis, highlight the main applications in the imaging and biosensing of a wide range of molecular targets, and discuss the challenges and prospects of CRISPR/Cas systems in live-cell imaging and biosensing. By illustrating the imaging and bio-sensing processes, we hope this review will guide the best use of the CRISPR/Cas in imaging and quantifying biological and clinical elements and inspire new ideas for better tool design in live-cell imaging and bioanalysis.
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Affiliation(s)
- Shuo Huang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Rui Dai
- Institute of Oceanography, Hainan University, Haikou 570228, China;
| | - Zhiqi Zhang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Han Zhang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Meng Zhang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Zhangjun Li
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Kangrui Zhao
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Wenjun Xiong
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Siyu Cheng
- College of Art and Design, Hainan University, Haikou 570228, China;
| | - Buhua Wang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Yi Wan
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
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24
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Ivanovaitė ŠRN, Paksaitė J, Kopu Stas A, Karzaitė G, Rutkauskas D, Silanskas A, Sasnauskas G, Zaremba M, Jones SK, Tutkus M. smFRET Detection of Cis and Trans DNA Interactions by the BfiI Restriction Endonuclease. J Phys Chem B 2023. [PMID: 37452775 PMCID: PMC10388346 DOI: 10.1021/acs.jpcb.3c03269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023]
Abstract
Protein-DNA interactions are fundamental to many biological processes. Proteins must find their target site on a DNA molecule to perform their function, and mechanisms for target search differ across proteins. Especially challenging phenomena to monitor and understand are transient binding events that occur across two DNA target sites, whether occurring in cis or trans. Type IIS restriction endonucleases rely on such interactions. They play a crucial role in safeguarding bacteria against foreign DNA, including viral genetic material. BfiI, a type IIS restriction endonuclease, acts upon a specific asymmetric sequence, 5-ACTGGG-3, and precisely cuts both upper and lower DNA strands at fixed locations downstream of this sequence. Here, we present two single-molecule Förster resonance energy-transfer-based assays to study such interactions in a BfiI-DNA system. The first assay focuses on DNA looping, detecting both "Phi"- and "U"-shaped DNA looping events. The second assay only allows in trans BfiI-target DNA interactions, improving the specificity and reducing the limits on observation time. With total internal reflection fluorescence microscopy, we directly observe on- and off-target binding events and characterize BfiI binding events. Our results show that BfiI binds longer to target sites and that BfiI rarely changes conformations during binding. This newly developed assay could be employed for other DNA-interacting proteins that bind two targets and for the dsDNA substrate BfiI-PAINT, a useful strategy for DNA stretch assays and other super-resolution fluorescence microscopy studies.
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Affiliation(s)
- Ša Ru Nė Ivanovaitė
- Department of Molecular Compound Physics, Center for Physical Sciences and Technology, Savanorių 231, Vilnius LT-02300, Lithuania
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
| | - Justė Paksaitė
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
| | - Aurimas Kopu Stas
- Department of Molecular Compound Physics, Center for Physical Sciences and Technology, Savanorių 231, Vilnius LT-02300, Lithuania
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
| | - Giedrė Karzaitė
- Department of Molecular Compound Physics, Center for Physical Sciences and Technology, Savanorių 231, Vilnius LT-02300, Lithuania
| | - Danielis Rutkauskas
- Department of Molecular Compound Physics, Center for Physical Sciences and Technology, Savanorių 231, Vilnius LT-02300, Lithuania
| | - Arunas Silanskas
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
| | - Giedrius Sasnauskas
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
| | - Mindaugas Zaremba
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
| | - Stephen K Jones
- VU LSC-EMBL Partnership for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius LT-10257, Lithuania
| | - Marijonas Tutkus
- Department of Molecular Compound Physics, Center for Physical Sciences and Technology, Savanorių 231, Vilnius LT-02300, Lithuania
- Vilnius University, Life Sciences Center, Institute of Biotechnology, Saulėtekio av. 7, Vilnius LT-10257, Lithuania
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25
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Tian T, Zhou X. CRISPR-Based Biosensing Strategies: Technical Development and Application Prospects. ANNUAL REVIEW OF ANALYTICAL CHEMISTRY (PALO ALTO, CALIF.) 2023; 16:311-332. [PMID: 37018798 DOI: 10.1146/annurev-anchem-090822-014725] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Biosensing based on CRISPR-Cas systems is a young but rapidly evolving technology. The unprecedented properties of the CRISPR-Cas system provide an innovative tool for developing new-generation biosensing strategies. To date, a series of nucleic acid and non-nucleic acid detection methods have been developed based on the CRISPR platform. In this review, we first introduce the core biochemical properties underpinning the development of CRISPR bioassays, such as diverse reaction temperatures, programmability in design, high reaction efficiency, and recognition specificity, and highlight recent efforts to improve these parameters. We then introduce the technical developments, including how to improve sensitivity and quantification capabilities, develop multiplex assays, achieve convenient one-pot assays, create advanced sensors, and extend the applications of detection. Finally, we analyze obstacles to the commercial application of CRISPR detection technology and explore development opportunities and directions.
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Affiliation(s)
- Tian Tian
- School of Life Sciences, South China Normal University, Guangzhou, China;
| | - Xiaoming Zhou
- School of Life Sciences, South China Normal University, Guangzhou, China;
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26
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Singh J, Liu KG, Allen A, Jiang W, Qin PZ. A DNA Unwinding Equilibrium Serves as a Checkpoint for CRISPR-Cas12a Target Discrimination. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.16.541046. [PMID: 37292754 PMCID: PMC10245671 DOI: 10.1101/2023.05.16.541046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
CRISPR-associated proteins such as Cas9 and Cas12a are programable RNA-guided nucleases that have emerged as powerful tools for genome manipulation and molecular diagnostics. However, these enzymes are prone to cleaving off-target sequences that contain mismatches between the RNA guide and DNA protospacer. In comparison to Cas9, Cas12a has demonstrated distinct sensitivity to protospacer-adjacent-motif (PAM) distal mismatches, and the molecular basis of Cas12a's enhanced target discrimination is of great interest. In this study, we investigated the mechanism of Cas12a target recognition using a combination of site-directed spin labeling, fluorescent spectroscopy, and enzyme kinetics. With a fully matched RNA guide, the data revealed an inherent equilibrium between a DNA unwound state and a DNA-paired duplex-like state. Experiments with off-target RNA guides and pre-nicked DNA substrates identified the PAM-distal DNA unwinding equilibrium as a mismatch sensing checkpoint prior to the first step of DNA cleavage. The data sheds light on the distinct targeting mechanism of Cas12a and may better inform CRISPR based biotechnology developments.
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27
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Jiang H, Li Y, Lv X, Deng Y, Li X. Recent advances in cascade isothermal amplification techniques for ultra-sensitive nucleic acid detection. Talanta 2023; 260:124645. [PMID: 37148686 PMCID: PMC10156408 DOI: 10.1016/j.talanta.2023.124645] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/30/2023] [Accepted: 05/03/2023] [Indexed: 05/08/2023]
Abstract
Nucleic acid amplification techniques have always been one of the hot spots of research, especially in the outbreak of COVID-19. From the initial polymerase chain reaction (PCR) to the current popular isothermal amplification, each new amplification techniques provides new ideas and methods for nucleic acid detection. However, limited by thermostable DNA polymerase and expensive thermal cycler, PCR is difficult to achieve point of care testing (POCT). Although isothermal amplification techniques overcome the defects of temperature control, single isothermal amplification is also limited by false positives, nucleic acid sequence compatibility, and signal amplification capability to some extent. Fortunately, efforts to integrating different enzymes or amplification techniques that enable to achieve intercatalyst communication and cascaded biotransformations may overcome the corner of single isothermal amplification. In this review, we systematically summarized the design fundamentals, signal generation, evolution, and application of cascade amplification. More importantly, the challenges and trends of cascade amplification were discussed in depth.
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Affiliation(s)
- Hao Jiang
- Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Yuan Li
- Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Xuefei Lv
- Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China.
| | - Yulin Deng
- Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
| | - Xiaoqiong Li
- Beijing Key Laboratory for Separation and Analysis in Biomedicine and Pharmaceuticals, School of Life Science, Beijing Institute of Technology, Beijing, 100081, China
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28
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Tian Z, Yan H, Zeng Y. Solid-Phase Extraction and Enhanced Amplification-Free Detection of Pathogens Integrated by Dual-Functional CRISPR-Cas12a. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.04.28.23289279. [PMID: 37162995 PMCID: PMC10168481 DOI: 10.1101/2023.04.28.23289279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Public healthcare demands effective and pragmatic diagnostic tools to address the escalating challenges in infection management in resource-limited areas. Recent advance in CRISPR-based biosensing promises the development of next-generation tools for disease diagnostics, including point-of-care (POC) testing for infectious diseases. Currently prevailing strategy of developing CRISPR assays exploits only the non-specific trans-cleavage function of a CRISPR-Cas12a/Cas13a system for detection and combines it with an additional pre-amplification reaction to enhance the sensitivity. In contrast to this single-function strategy, here we present a new approach that collaboratively integrates the dual functions of CRISPR-Cas12a: sequence-specific binding and trans-cleavage activity. With this approach, we developed a POC nucleic acid assay termed Solid-Phase Extraction and Enhanced Detection assay Integrated by CRISPR-Cas12a (SPEEDi-CRISPR) that negates the need for preamplification but significantly improves the detection of limit (LOD) from the pM to fM level. Specifically, using Cas12a-coated magnetic beads, this assay combines efficient solid-phase extraction and enrichment of DNA targets enabled by the sequence-specific affinity of CRISPR-Cas12a with the fluorogenic detection by the activated Cas12a on beads. Our proof-of-concept study demonstrated that the SPEEDi-CRISPR assay affords an improved detection sensitivity for human papillomavirus (HPV)-18 with a LOD of 2.3 fM and excellent specificity to discriminate HPV-18 from HPV-16, Parvovirus B19, and scramble HPV-18. Furthermore, this robust assay was readily coupled with a portable smartphone-based fluorescence detector and a lateral flow assay for quantitative detection and visualized readout, respectively. Overall, these results should suggest that our dual-function strategy could pave a new way for developing the next-generation CRISPR diagnostics and that the SPEEDi-CRISPR assay provides a potentially useful tool for point-of-care testing.
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29
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Ma L, Liao D, Zhao Z, Kou J, Guo H, Xiong X, Man S. Sensitive Small Molecule Aptasensing based on Hybridization Chain Reaction and CRISPR/Cas12a Using a Portable 3D-Printed Visualizer. ACS Sens 2023; 8:1076-1084. [PMID: 36651835 DOI: 10.1021/acssensors.2c02097] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Next-generation biosensing tools based on CRISPR/Cas have revolutionized the molecular detection. A number of CRISPR/Cas-based biosensors have been reported for the detection of nucleic acid targets. The establishment of efficient methods for non-nucleic acid target detection would further broaden the scope of this technique, but up to now, the concerning research is limited. In the current study, we reported a versatile biosensing platform for non-nucleic acid small-molecule detection called SMART-Cas12a (small-molecule aptamer regulated test using CRISPR/Cas12a). Simply, hybridization chain reaction cascade signal amplification was first trigged by functional nucleic acid (aptamer) through target binding. Then, the CRISPR/Cas system was integrated to recognize the amplified products followed by activation of the trans-cleavage. As such, the target can be ingeniously converted to nucleic acid signals and then fluorescent signals that can be readily visualized and analyzed by a customized 3D-printed visualizer with the help of a home-made App-enabled smartphone. Adenosine triphosphate was selected as a model target, and under the optimized conditions, we achieved fine analytical performance with a linear range from 0.1 to 750 μM and a detection limit of 1.0 nM. The satisfactory selectivity and recoveries that we have obtained further demonstrated this method to be suitable for a complex sample environment. The sample-to-answer time was less than 100 min. Our work not only expanded the reach of the CRISPR-Cas system in biosensing but also provided a prototype method that can be generalized for detecting a wider range of analytes with desirable adaptability, sensitivity, specificity, and on-site capability.
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Affiliation(s)
- Long Ma
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Dan Liao
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Zhiying Zhao
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Jun Kou
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Haoyu Guo
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
| | - Xin Xiong
- College of Artificial Intelligence, Tianjin University of Science and Technology, Tianjin 3000457, China
| | - Shuli Man
- State Key Laboratory of Food Nutrition and Safety, Key Laboratory of Industrial Microbiology, Ministry of Education, Tianjin Key Laboratory of Industry Microbiology, National and Local United Engineering Lab of Metabolic Control Fermentation Technology, China International Science and Technology Cooperation Base of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, China
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30
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Avaro AS, Santiago JG. A critical review of microfluidic systems for CRISPR assays. LAB ON A CHIP 2023; 23:938-963. [PMID: 36601854 DOI: 10.1039/d2lc00852a] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Reviewed are nucleic acid detection assays that incorporate clustered regularly interspaced short palindromic repeats (CRISPR)-based diagnostics and microfluidic devices and techniques. The review serves as a reference for researchers who wish to use CRISPR-Cas systems for diagnostics in microfluidic devices. The review is organized in sections reflecting a basic five-step workflow common to most CRISPR-based assays. These steps are analyte extraction, pre-amplification, target recognition, transduction, and detection. The systems described include custom microfluidic chips and custom (benchtop) chip control devices for automated assays steps. Also included are partition formats for digital assays and lateral flow biosensors as a readout modality. CRISPR-based, microfluidics-driven assays offer highly specific detection and are compatible with parallel, combinatorial implementation. They are highly reconfigurable, and assays are compatible with isothermal and even room temperature operation. A major drawback of these assays is the fact that reports of kinetic rates of these enzymes have been highly inconsistent (many demonstrably erroneous), and the low kinetic rate activity of these enzymes limits achievable sensitivity without pre-amplification. Further, the current state-of-the-art of CRISPR assays is such that nearly all systems rely on off-chip assays steps, particularly off-chip sample preparation.
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Affiliation(s)
- Alexandre S Avaro
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
| | - Juan G Santiago
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA.
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31
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Rananaware SR, Vesco EK, Shoemaker GM, Anekar SS, Sandoval LSW, Meister KS, Macaluso NC, Nguyen LT, Jain PK. Programmable RNA detection with CRISPR-Cas12a. RESEARCH SQUARE 2023:rs.3.rs-2549171. [PMID: 36824842 PMCID: PMC9949221 DOI: 10.21203/rs.3.rs-2549171/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
CRISPR is a prominent bioengineering tool and the type V CRISPR-associated protein complex, Cas12a, is widely used in diagnostic platforms due to its innate ability to cleave DNA substrates. Here we demonstrate that Cas12a can also be programmed to directly detect RNA substrates without the need for reverse transcription or strand displacement. We discovered that while the PAM-proximal "seed" region of the crRNA exclusively recognizes DNA for initiating trans-cleavage, the PAM-distal region or 3'-end of the crRNA can tolerate both RNA and DNA substrates. Utilizing this property, we developed a method named Split Activators for Highly Accessible RNA Analysis or 'SAHARA' to detect RNA sequences at the PAM-distal region of the crRNA by merely supplying a short ssDNA or a PAM containing dsDNA to the seed region. Notably, SAHARA is Mg2+ concentration- and pH-dependent, and it was observed to work robustly at room temperature with multiple orthologs of Cas12a. SAHARA also displayed a significant improvement in the specificity for target recognition as compared to the wild-type CRISPR-Cas12a, at certain positions along the crRNA. By employing SAHARA we achieved amplification-free detection of picomolar concentrations of miRNA-155 and hepatitis C virus RNA. Finally, SAHARA can use a PAM-proximal DNA as a switch to control the trans-cleavage activity of Cas12a for the detection of both DNA and RNA targets. With this, multicomplex arrays can be made to detect distinct DNA and RNA targets with pooled crRNA/Cas12a complexes. In conclusion, SAHARA is a simple, yet powerful nucleic acid detection platform based on Cas12a that can be applied in a multiplexed fashion and potentially be expanded to other CRISPR-Cas enzymes.
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Affiliation(s)
- Santosh R. Rananaware
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Emma K. Vesco
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Grace M. Shoemaker
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Swapnil S. Anekar
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | | | - Katelyn S. Meister
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Nicolas C. Macaluso
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Long T. Nguyen
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Piyush K. Jain
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
- UF Health Cancer Center, University of Florida, Gainesville, Florida, USA
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32
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Rananaware SR, Vesco EK, Shoemaker GM, Anekar SS, Sandoval LSW, Meister KS, Macaluso NC, Nguyen LT, Jain PK. Programmable RNA detection with CRISPR-Cas12a. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.29.525716. [PMID: 36778248 PMCID: PMC9915489 DOI: 10.1101/2023.01.29.525716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
CRISPR is a prominent bioengineering tool and the type V CRISPR-associated protein complex, Cas12a, is widely used in diagnostic platforms due to its innate ability to cleave DNA substrates. Here we demonstrate that Cas12a can also be programmed to directly detect RNA substrates without the need for reverse transcription or strand displacement. We discovered that while the PAM-proximal "seed" region of the crRNA exclusively recognizes DNA for initiating trans- cleavage, the PAM-distal region or 3'-end of the crRNA can tolerate both RNA and DNA substrates. Utilizing this property, we developed a method named Split Activators for Highly Accessible RNA Analysis or 'SAHARA' to detect RNA sequences at the PAM-distal region of the crRNA by merely supplying a short ssDNA or a PAM containing dsDNA to the seed region. Notably, SAHARA is Mg 2+ concentration- and pH-dependent, and it was observed to work robustly at room temperature with multiple orthologs of Cas12a. SAHARA also displayed a significant improvement in the specificity for target recognition as compared to the wild-type CRISPR-Cas12a, at certain positions along the crRNA. By employing SAHARA we achieved amplification-free detection of picomolar concentrations of miRNA-155 and hepatitis C virus RNA. Finally, SAHARA can use a PAM-proximal DNA as a switch to control the trans-cleavage activity of Cas12a for the detection of both DNA and RNA targets. With this, multicomplex arrays can be made to detect distinct DNA and RNA targets with pooled crRNA/Cas12a complexes. In conclusion, SAHARA is a simple, yet powerful nucleic acid detection platform based on Cas12a that can be applied in a multiplexed fashion and potentially be expanded to other CRISPR-Cas enzymes. Abstract Figure
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Affiliation(s)
- Santosh R. Rananaware
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Emma K. Vesco
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Grace M. Shoemaker
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Swapnil S. Anekar
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | | | - Katelyn S. Meister
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Nicolas C. Macaluso
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Long T. Nguyen
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
| | - Piyush K. Jain
- Department of Chemical Engineering, University of Florida, Gainesville, Florida, USA
- Department of Molecular Genetics and Microbiology, University of Florida, Gainesville, Florida, USA
- UF Health Cancer Center, University of Florida, Gainesville, Florida, USA
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Japanese Regulatory Framework and Approach for Genome-edited Foods Based on Latest Scientific Findings. FOOD SAFETY (TOKYO, JAPAN) 2022; 10:113-128. [PMID: 36619008 PMCID: PMC9789915 DOI: 10.14252/foodsafetyfscj.d-21-00016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
The food supply system is facing important challenges and its sustainability has to be considered. Genome-editing technology, which accelerates the development of new variety, could be used to achieve sustainable development goals, thereby protecting the environment and ensuring the stable production of food for an increasing global population. The most widely used genome-editing tool, CRISPR/Cas9, is easy to use, affordable, and versatile. Foods produced by genome-editing technologies have been developed worldwide to create novel traits. In the first half of the review, the latest scientific findings on genome-editing technologies are summarized, and the technical challenge in genome sequence analysis are clarified. CRISPR/Cas9 has versatile alternative techniques, such as base editor and prime editor. Genome sequencing technology has developed rapidly in recent years. However, it is still difficult to detect large deletions and structural variations. Long-read sequencing technology would solve this challenge. In the second part, regulatory framework and approach for genome-edited foods is introduced. The four government ministries, including the Ministry of Environment, the Ministry of Agriculture, Forestry and Fisheries, and the Ministry of Health, Labour and Welfare (MHLW), started to discuss how the regulation should be implemented in 2019. The SDN-1 technique is excluded from the current genetically modified organism (GMO) regulation. The Japanese regulatory framework includes pre-submission consultation and submission of notification form. In the last part of this review, transparency of regulatory framework and consumer confidence were described. Since maintaining consumer trust is vital, transparency of regulatory framework is a key to consumers. The information of notification process on approved genome-edited foods is made public immediately. This review will help regulators build regulatory frameworks, and lead to harmonization of the framework between the countries.
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Liu S, Xie T, Huang Z, Pei X, Li S, He Y, Tong Y, Liu G. Systematically investigating the fluorescent signal readout of CRISPR-Cas12a for highly sensitive SARS-CoV-2 detection. SENSORS AND ACTUATORS. B, CHEMICAL 2022; 373:132746. [PMID: 36212739 PMCID: PMC9527496 DOI: 10.1016/j.snb.2022.132746] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/17/2022] [Accepted: 09/25/2022] [Indexed: 05/31/2023]
Abstract
The CRISPR/Cas system is widely used for molecular diagnostics after the discovery of trans-cleavage activity, especially now with the COVID-19 outbreak. However, the majority of contemporary trans-cleavage activity-based CRISPR/Cas biosensors exploited standard single-strand DNA (ssDNA) reporters, which were based on the FRET principle from pioneering research. An in-depth comparison and understanding of various fluorescent readout types are essential to facilitate the outstanding analytical performance of CRISPR probes. We investigated various types of fluorescent reporters of Cas12a comprehensively. Results show that trans-cleavage of Cas12a is not limited to ssDNA and dsDNA reporters, but can be extended to molecular beacons (MB). And MB reporters can achieve superior analytical performance compared with ssDNA and ds DNA reporters at the same conditions. Accordingly, we developed a highly-sensitive SARS-CoV-2 detection with the sensitivity as low as 100 fM were successfully achieved without amplification strategy. The model target of ORF1a could robustly identify the current widespread emerging SARS-CoV-2 variants. A real coronavirus GX/P2V instead of SARS-CoV-2 were chosen for practical application validation. And a minimum of 27 copies/mL was achieved successfully. This inspiration can also be applied to other Cas proteins with trans-cleavage activity, which provides new perspectives for simple, highly-sensitive and universal molecular diagnosis in various applications.
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Affiliation(s)
- Sitong Liu
- College of Chemistry and Materials Engineering and Institute of Cosmetic Regulatory Science, Beijing Technology and Business University, Beijing 100048, PR China
| | - Tie Xie
- College of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, PR China
| | - Zhaohe Huang
- College of Chemistry and Materials Engineering and Institute of Cosmetic Regulatory Science, Beijing Technology and Business University, Beijing 100048, PR China
| | - Xiaojing Pei
- College of Chemistry and Materials Engineering and Institute of Cosmetic Regulatory Science, Beijing Technology and Business University, Beijing 100048, PR China
| | - Shujing Li
- College of Chemistry and Materials Engineering and Institute of Cosmetic Regulatory Science, Beijing Technology and Business University, Beijing 100048, PR China
| | - Yifan He
- College of Chemistry and Materials Engineering and Institute of Cosmetic Regulatory Science, Beijing Technology and Business University, Beijing 100048, PR China
| | - Yigang Tong
- College of Chemistry and Materials Engineering, Beijing Technology and Business University, Beijing 100048, PR China
| | - Guoqi Liu
- Biotecnovo (Beijing) Co.,LTD, Beijing Economic and Technological Development Zone, Beijing, PR China
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Misiurina MA, Chirinskaite AV, Fotina AS, Zelinsky AA, Sopova JV, Leonova EI. New PAM Improves the Single-Base Specificity of crRNA-Guided LbCas12a Nuclease. LIFE (BASEL, SWITZERLAND) 2022; 12:life12111927. [PMID: 36431062 PMCID: PMC9698171 DOI: 10.3390/life12111927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 11/22/2022]
Abstract
The RNA-guided Cas12a nuclease forms a complex with a CRISPR RNA (crRNA) to cleave the double-stranded DNA target. Among others, Cas12a protein from Lachnospiraceae bacterium (LbCas12a) is widely used for biomedical research. For target recognition, LbCas12a requires a specific nucleotide sequence, named a protospacer adjacent motif (PAM). Besides the canonical TTTV PAM, LbCas12a can recognize other suboptimal PAMs. We examined a novel TTAA PAM for the LbCas12a nuclease and found that the specificity of cleavage was increased. We found that single nucleotide substitutions at all positions of the guide RNA except the 20th position blocked the cleavage of the target DNA. The type of nucleotide substitutions (U-A, U-C or U-G) did not affect the efficiency of cleavage in the 20th position. When we used the canonical PAM under the same conditions, we observed the cleavage of target DNA by LbCas12a in many positions, showing less specificity in given conditions. The efficiency and specificity of the LbCas12a nuclease were evaluated both by gel-electrophoresis and using FAM-labeled single-stranded probes. We were able to assess the change in fluorescence intensity only for several variants of guide RNAs. High specificity allows us to type single nucleotide substitutions and small deletions/insertions (1-2 nucleotides) and look for target mutations when knocking out.
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Affiliation(s)
- Mariia A. Misiurina
- Center of Transgenesis and Genome Editing, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
| | - Angelina V. Chirinskaite
- Center of Transgenesis and Genome Editing, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
| | - Aleksandra S. Fotina
- Center of Transgenesis and Genome Editing, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
| | - Andrey A. Zelinsky
- Laboratory of Amyloid Biology, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
| | - Julia V. Sopova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
- Laboratory of Amyloid Biology, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
| | - Elena I. Leonova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, Universitetskaja Emb., 7/9, 199034 St. Petersburg, Russia
- Correspondence:
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36
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Wörle E, Newman A, D’Silva J, Burgio G, Grohmann D. Allosteric activation of CRISPR-Cas12a requires the concerted movement of the bridge helix and helix 1 of the RuvC II domain. Nucleic Acids Res 2022; 50:10153-10168. [PMID: 36107767 PMCID: PMC9508855 DOI: 10.1093/nar/gkac767] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 08/19/2022] [Accepted: 08/26/2022] [Indexed: 11/25/2022] Open
Abstract
Nucleases derived from the prokaryotic defense system CRISPR-Cas are frequently re-purposed for gene editing and molecular diagnostics. Hence, an in-depth understanding of the molecular mechanisms of these enzymes is of crucial importance. We focused on Cas12a from Francisella novicida (FnCas12a) and investigated the functional role of helix 1, a structural element that together with the bridge helix (BH) connects the recognition and the nuclease lobes of FnCas12a. Helix 1 is structurally connected to the lid domain that opens upon DNA target loading thereby activating the active site of FnCas12a. We probed the structural states of FnCas12a variants altered in helix 1 and/or the bridge helix using single-molecule FRET measurements and assayed the pre-crRNA processing, cis- and trans-DNA cleavage activity. We show that helix 1 and not the bridge helix is the predominant structural element that confers conformational stability of FnCas12a. Even small perturbations in helix 1 lead to a decrease in DNA cleavage activity while the structural integrity is not affected. Our data, therefore, implicate that the concerted remodeling of helix 1 and the bridge helix upon DNA binding is structurally linked to the opening of the lid and therefore involved in the allosteric activation of the active site.
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Affiliation(s)
- Elisabeth Wörle
- Institute of Microbiology & Archaea Centre, Single-Molecule Biochemistry Lab, University of Regensburg, 93053 Regensburg, Germany
| | - Anthony Newman
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Jovita D’Silva
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Gaetan Burgio
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Dina Grohmann
- Institute of Microbiology & Archaea Centre, Single-Molecule Biochemistry Lab, University of Regensburg, 93053 Regensburg, Germany
- Regensburg Center of Biochemistry (RCB), University of Regensburg, 93053 Regensburg, Germany
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37
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Naqvi MM, Lee L, Montaguth OET, Diffin FM, Szczelkun MD. CRISPR-Cas12a-mediated DNA clamping triggers target-strand cleavage. Nat Chem Biol 2022; 18:1014-1022. [PMID: 35836018 PMCID: PMC9395263 DOI: 10.1038/s41589-022-01082-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 06/08/2022] [Indexed: 01/19/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas12a is widely used for genome editing and diagnostics, so it is important to understand how RNA-guided DNA recognition activates the cleavage of the target strand (TS) following non-target-strand (NTS) cleavage. Here we used single-molecule magnetic tweezers, gel-based assays and nanopore sequencing to explore DNA unwinding and cleavage. In addition to dynamic and heterogenous R-loop formation, we also directly observed transient double-stranded DNA unwinding downstream of the 20-bp heteroduplex and, following NTS cleavage, formation of a hyperstable 'clamped' Cas12a-DNA intermediate necessary for TS cleavage. Annealing of a 4-nucleotide 3' CRISPR RNA overhang to the unwound TS downstream of the heteroduplex inhibited clamping and slowed TS cleavage by ~16-fold. Alanine substitution of a conserved aromatic amino acid in the REC2 subdomain that normally caps the R-loop relieved this inhibition but favoured stabilisation of unwound states, suggesting that the REC2 subdomain regulates access of the 3' CRISPR RNA to downstream DNA.
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Affiliation(s)
- Mohsin M Naqvi
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Laura Lee
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Oscar E Torres Montaguth
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Fiona M Diffin
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol, UK.
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38
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Yoshimi K, Takeshita K, Kodera N, Shibumura S, Yamauchi Y, Omatsu M, Umeda K, Kunihiro Y, Yamamoto M, Mashimo T. Dynamic mechanisms of CRISPR interference by Escherichia coli CRISPR-Cas3. Nat Commun 2022; 13:4917. [PMID: 36042215 PMCID: PMC9427990 DOI: 10.1038/s41467-022-32618-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/09/2022] [Indexed: 11/09/2022] Open
Abstract
Type I CRISPR-Cas3 uses an RNA-guided multi Cas-protein complex, Cascade, which detects and degrades foreign nucleic acids via the helicase-nuclease Cas3 protein. Despite many studies using cryoEM and smFRET, the precise mechanism of Cas3-mediated cleavage and degradation of target DNA remains elusive. Here we reconstitute the CRISPR-Cas3 system in vitro to show how the Escherichia coli Cas3 (EcoCas3) with EcoCascade exhibits collateral non-specific single-stranded DNA (ssDNA) cleavage and target specific DNA degradation. Partial binding of EcoCascade to target DNA with tolerated mismatches within the spacer sequence, but not the PAM, elicits collateral ssDNA cleavage activity of recruited EcoCas3. Conversely, stable binding with complete R-loop formation drives EcoCas3 to nick the non-target strand (NTS) in the bound DNA. Helicase-dependent unwinding then combines with trans ssDNA cleavage of the target strand and repetitive cis cleavage of the NTS to degrade the target double-stranded DNA (dsDNA) substrate. High-speed atomic force microscopy demonstrates that EcoCas3 bound to EcoCascade repeatedly reels and releases the target DNA, followed by target fragmentation. Together, these results provide a revised model for collateral ssDNA cleavage and target dsDNA degradation by CRISPR-Cas3, furthering understanding of type I CRISPR priming and interference and informing future genome editing tools.
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Affiliation(s)
- Kazuto Yoshimi
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.,Division of Genome Engineering, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan
| | - Kohei Takeshita
- Life Science Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan
| | - Noriyuki Kodera
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | | | - Yuko Yamauchi
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan
| | - Mine Omatsu
- Life Science Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan.,Laboratory of Macromolecular Dynamics and X-ray Crystallography, Department of Life Science, University of Hyogo, Hyogo, 678-1297, Japan
| | - Kenichi Umeda
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | | | - Masaki Yamamoto
- Life Science Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan.,Laboratory of Macromolecular Dynamics and X-ray Crystallography, Department of Life Science, University of Hyogo, Hyogo, 678-1297, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan. .,Division of Genome Engineering, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.
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39
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Vasilev R, Gunitseva N, Shebanova R, Korzhenkov A, Vlaskina A, Evteeva M, Polushkina I, Nikitchina N, Toshchakov S, Kamenski P, Patrushev M, Mazunin I. Targeted Modification of Mammalian DNA by a Novel Type V Cas12a Endonuclease from Ruminococcus bromii. Int J Mol Sci 2022; 23:ijms23169289. [PMID: 36012553 PMCID: PMC9409102 DOI: 10.3390/ijms23169289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/12/2022] [Accepted: 08/16/2022] [Indexed: 11/25/2022] Open
Abstract
Type V Cas12a nucleases are DNA editors working in a wide temperature range and using expanded protospacer-adjacent motifs (PAMs). Though they are widely used, there is still a demand for discovering new ones. Here, we demonstrate a novel ortholog from Ruminococcus bromii sp. entitled RbCas12a, which is able to efficiently cleave target DNA templates, using the particularly high accessibility of PAM 5′-YYN and a relatively wide temperature range from 20 °C to 42 °C. In comparison to Acidaminococcus sp. (AsCas12a) nuclease, RbCas12a is capable of processing DNA more efficiently, and can be active upon being charged by spacer-only RNA at lower concentrations in vitro. We show that the human-optimized RbCas12a nuclease is also active in mammalian cells, and can be applied for efficient deletion incorporation into the human genome. Given the advantageous properties of RbCas12a, this enzyme shows potential for clinical and biotechnological applications within the field of genome editing.
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Affiliation(s)
- Ruslan Vasilev
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
- Correspondence: (R.V.); (I.M.)
| | - Natalia Gunitseva
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Regina Shebanova
- Center of Life Sciences, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia
| | - Aleksei Korzhenkov
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Anna Vlaskina
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Marta Evteeva
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Irina Polushkina
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Natalia Nikitchina
- Center of Life Sciences, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia
- UMR7156–Molecular Genetics, Genomics, Microbiology, University of Strasbourg and Centre National de la Recherche Scientifique (CNRS), 67000 Strasbourg, France
| | - Stepan Toshchakov
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Piotr Kamenski
- Faculty of Biology, Lomonosov Moscow State University, 119991 Moscow, Russia
| | - Maxim Patrushev
- Kurchatov Genomics Center, National Research Center “Kurchatov Institute”, 123098 Moscow, Russia
| | - Ilya Mazunin
- Center of Life Sciences, Skolkovo Institute of Science and Technology, 143026 Moscow, Russia
- Medical Genomics LLC, 119192 Moscow, Russia
- Correspondence: (R.V.); (I.M.)
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40
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Mighell TL, Nishida A, O'Connell BL, Miller CV, Grindstaff S, Thornton CA, Adey AC, Doherty D, O'Roak BJ. Cas12a-Capture: A Novel, Low-Cost, and Scalable Method for Targeted Sequencing. CRISPR J 2022; 5:548-557. [PMID: 35833801 PMCID: PMC9419982 DOI: 10.1089/crispr.2021.0140] [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: 11/02/2021] [Accepted: 04/25/2022] [Indexed: 11/12/2022] Open
Abstract
Targeted sequencing remains a valuable technique for clinical and research applications. However, many existing technologies suffer from pervasive guanine-cytosine (GC) sequence content bias, high input DNA requirements, and high cost for custom panels. We have developed Cas12a-Capture, a low-cost and highly scalable method for targeted sequencing. The method utilizes preprogrammed guide RNAs to direct CRISPR-Cas12a cleavage of double-stranded DNA in vitro and then takes advantage of the resulting four to five nucleotide overhangs for selective ligation with a custom sequencing adapter. Addition of a second sequencing adapter and enrichment for ligation products generates a targeted sequence library. We first performed a pilot experiment with 7176 guides targeting 3.5 Mb of DNA. Using these data, we modeled the sequence determinants of Cas12a-Capture efficiency, then designed an optimized set of 11,438 guides targeting 3.0 Mb. The optimized guide set achieves an average 64-fold enrichment of targeted regions with minimal GC bias. Cas12a-Capture variant calls had strong concordance with Illumina Platinum Genome calls, especially for single nucleotide variants, which could be improved by applying basic variant quality heuristics. We believe Cas12a-Capture has a wide variety of potential clinical and research applications and is amendable for selective enrichment for any double-stranded DNA template or genome.
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Affiliation(s)
- Taylor L. Mighell
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
| | - Andrew Nishida
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
| | - Brendan L. O'Connell
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
| | - Caitlin V. Miller
- Department of Pediatrics, University of Washington, Seattle, Washington, USA; and Portland, Oregon, USA
| | - Sally Grindstaff
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
| | - Casey A. Thornton
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
| | - Andrew C. Adey
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
- Knight Cardiovascular Institute, Portland, Oregon, USA
| | - Daniel Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington, USA; and Portland, Oregon, USA
| | - Brian J. O'Roak
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, Oregon, USA; Portland, Oregon, USA
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41
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Yang S, Joesaar A, Bögels BWA, Mann S, de Greef TFA. Protocellular CRISPR/Cas‐Based Diffusive Communication Using Transcriptional RNA Signaling. Angew Chem Int Ed Engl 2022; 61:e202202436. [PMID: 35385207 PMCID: PMC9320857 DOI: 10.1002/anie.202202436] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Indexed: 11/29/2022]
Abstract
Protocells containing enzyme‐driven biomolecular circuits that can process and exchange information offer a promising approach for mimicking cellular features and developing molecular information platforms. Here, we employ synthetic transcriptional circuits together with CRISPR/Cas‐based DNA processing inside semipermeable protein‐polymer microcompartments. We first establish a transcriptional protocell that can be activated by external DNA strands and produce functional RNA aptamers. Subsequently, we engineer a transcriptional module to generate RNA strands functioning as diffusive signals that can be sensed by neighboring protocells and trigger the activation of internalized DNA probes or localization of Cas nucleases. Our results highlight the opportunities to combine CRISPR/Cas machinery and DNA nanotechnology for protocellular communication and provide a step towards the development of protocells capable of distributed molecular information processing.
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Affiliation(s)
- Shuo Yang
- Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
| | - Alex Joesaar
- Department of Bionanoscience Kavli Institute of Nanoscience Delft University of Technology 2629 HZ Delft The Netherlands
| | - Bas W. A. Bögels
- Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
| | - Stephen Mann
- Centre for Protolife Research and Centre for Organized Matter Chemistry School of Chemistry and Max Planck-Bristol Centre for Minimal Biology School of Chemistry, University of Bristol Bristol BS8 1TS UK
- School of Materials Science and Engineering Institute of Molecular Medicine (IMM) Renji Hospital Shanghai Jiao Tong University School of Medicine Shanghai Jiao Tong University Shanghai 200240 P. R. China
| | - Tom F. A. de Greef
- Institute for Complex Molecular Systems Eindhoven University of Technology P.O. Box 513 5600 MB Eindhoven The Netherlands
- Computational Biology group Department of Biomedical Engineering Eindhoven University of Technology The Netherlands
- Institute for Molecules and Materials Faculty of Science Radboud University Radboud University Heyendaalseweg 135 6525 AJ Nijmegen The Netherlands
- Center for Living Technologies, Alliance TU/e, WUR, UU, UMC Utrecht Princetonlaan 6 3584 CB Utrecht The Netherlands
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42
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Marino ND, Pinilla-Redondo R, Bondy-Denomy J. CRISPR-Cas12a targeting of ssDNA plays no detectable role in immunity. Nucleic Acids Res 2022; 50:6414-6422. [PMID: 35670674 PMCID: PMC9226536 DOI: 10.1093/nar/gkac462] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 05/12/2022] [Accepted: 05/23/2022] [Indexed: 12/17/2022] Open
Abstract
CRISPR-Cas12a (Cpf1) is a bacterial RNA-guided nuclease that cuts double-stranded DNA (dsDNA) at sites specified by a CRISPR RNA (crRNA) guide. Additional activities have been ascribed to this enzyme in vitro: site-specific (cis) single-stranded DNA (ssDNA) cleavage and indiscriminate (trans) degradation of ssDNA, RNA, and dsDNA after activation by a complementary target. The ability of Cas12a to cleave nucleic acids indiscriminately has been harnessed for many applications, including diagnostics, but it remains unknown if it contributes to bacterial immunity. Here, we provide evidence that cleavage of ssDNA in cis or in trans by Cas12a is insufficient to impact immunity. Using LbCas12a expressed in either Pseudomonas aeruginosa or Escherichia coli, we observed that cleavage of dsDNA targets did not elicit cell death or dormancy, suggesting insignificant levels of collateral damage against host RNA or DNA. Canonical immunity against invasive dsDNA also had no impact on the replicative fitness of co-infecting dsDNA phage, ssDNA phage or plasmid in trans. Lastly, crRNAs complementary to invasive ssDNA did not provide protection, suggesting that ssDNA cleavage does not occur in vivo or is insignificant. Overall, these results suggest that CRISPR-Cas12a immunity predominantly occurs via canonical targeting of dsDNA, and that the other activities do not significantly impact infection outcomes.
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Affiliation(s)
- Nicole D Marino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Rafael Pinilla-Redondo
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Joseph Bondy-Denomy
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
- Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Innovative Genomics Institute, Berkeley, CA 94720, USA
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43
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Zhang W, Shi R, Dong K, Hu H, Shu W, Mu Y, Yan B, Li L, Xiao X, Wang H. The Off-Target Effect of CRISPR-Cas12a System toward Insertions and Deletions between Target DNA and crRNA Sequences. Anal Chem 2022; 94:8596-8604. [PMID: 35670376 DOI: 10.1021/acs.analchem.1c05499] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The CRISPR-Cas12a system is a new type of genome editing tool with high efficiency and targeting. However, other sequences in the genome may also be cleaved nonspecifically, resulting in unavoidable off-target effects. Therefore, it is necessary to learn more about the mechanism of CRISPR-Cas12a to recognize target sequences to avoid its off-target effects. Here, we show that insertion (DNA bubble) or deletion (RNA bubble) of the target dsDNA sequence compared with the crRNA sequence, the CRISPR-Cas12a system can still recognize and cleave the target dsDNA sequence. We conclude that the tolerance of CRISPR-Cas12a to the bubbles is closely related to the location and size of the bubble and the GC base content of crRNA. In addition, we used the unique property of CRISPR-Cas12a to invent a new method to detect mutations and successfully detect the CD41-42(-CTTT) mutation. The detection limit of this method is 0.001%. Overall, our results strongly indicate that in addition to considering off-target effects caused by base mismatches, a comprehensive off-target analysis of the insertion and deletion of the target dsDNA sequence is required, and specific guidelines for effectively reducing potential off-target cleavage are proposed, to improve the safety manual of CRISPR-Cas12a biological application.
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Affiliation(s)
- Wei Zhang
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Rui Shi
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Kejun Dong
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Hao Hu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Wan Shu
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
| | - Yaoqin Mu
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Bei Yan
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Longjie Li
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,School of Life Science and Technology, Wuhan Polytechnic University, Wuhan 430023, China
| | - Xianjin Xiao
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.,Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.,Department of Laboratory Medicine, Tongji hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430000, China.,Center of Reproductive Medicine, Changsha Hospital for Maternal and Child Health Care of Hunan Normal University, Changsha 410000, China
| | - Hongbo Wang
- Department of Obstetrics and Gynecology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China
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44
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Lei R, Li L, Wu P, Fei X, Zhang Y, Wang J, Zhang D, Zhang Q, Yang N, Wang X. RPA/CRISPR/Cas12a-Based On-Site and Rapid Nucleic Acid Detection of Toxoplasma gondii in the Environment. ACS Synth Biol 2022; 11:1772-1781. [PMID: 35471824 DOI: 10.1021/acssynbio.1c00620] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Toxoplasma gondii is an opportunistic pathogen widely distributed within the world, poses a huge threat to human health, and causes significant economic losses to the livestock industry. Herein, we developed a portable one-pot detection of T. gondii by combining recombinase polymerase amplification (RPA) and a clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system. A glass microfiber filter device used for the first step can efficiently extract T. gondii from low-concentration samples. The lyophilized RPA reagents and Cas12a/crRNA reagents are prestored in one Eppendorf tube, and both reactions can be performed on a low-cost thermal controller (∼37 °C), avoiding the drawbacks of the step-by-step addition of components. The developed RPA/CRISPR/Cas12a system exhibits a high selectivity toward the B1 gene amplicon of T. gondii over other parasites with a limit of detection of 3.3 copies/μL. The visual signal readout can be easily realized by a fluorometer or lateral-flow strip. A portable suitcase containing the minimum equipment and lyophilized reagents was adopted for the rapid determination of T. gondii in heavily polluted landfill leachate. This system presents rapidness, robustness and on-site features for the detection of nucleic acids of the parasite, making it a promising tool for field applications in remote areas.
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Affiliation(s)
- Rong Lei
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing100176, China
| | - Limei Li
- School of Life Science and Biotechnology, Dalian University, Dalian, Liaoning116622, China
| | - Pinshan Wu
- Institute of Plant Quarantine, Chinese Academy of Inspection and Quarantine, Beijing100176, China
| | - Xinyu Fei
- College of Land and Environment, Shenyang Agricultural University, Shenyang, Liaoning110866, China
| | - Yuting Zhang
- Food Science College, Shenyang Agricultural University, Shenyang, Liaoning110866, China
| | - Jingyi Wang
- College of Information and Electrical Engineering, Shenyang Agricultural University, Shenyang, Liaoning110866, China
| | - Di Zhang
- School of Life Science and Biotechnology, Dalian University, Dalian, Liaoning116622, China
| | - Qingfang Zhang
- School of Life Science and Biotechnology, Dalian University, Dalian, Liaoning116622, China
| | - Na Yang
- College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, Liaoning110866, China
| | - Xinyi Wang
- School of Life Science and Biotechnology, Dalian University, Dalian, Liaoning116622, China
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45
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Pan C, Li G, Malzahn AA, Cheng Y, Leyson B, Sretenovic S, Gurel F, Coleman GD, Qi Y. Boosting plant genome editing with a versatile CRISPR-Combo system. NATURE PLANTS 2022; 8:513-525. [PMID: 35596077 DOI: 10.1038/s41477-022-01151-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 04/11/2022] [Indexed: 05/06/2023]
Abstract
CRISPR-Cas9, its derived base editors and CRISPR activation systems have greatly aided genome engineering in plants. However, these systems are mostly used separately, leaving their combinational potential largely untapped. Here we develop a versatile CRISPR-Combo platform, based on a single Cas9 protein, for simultaneous genome editing (targeted mutagenesis or base editing) and gene activation in plants. We showcase the powerful applications of CRISPR-Combo for boosting plant genome editing. First, CRISPR-Combo is used to shorten the plant life cycle and reduce the efforts in screening transgene-free genome-edited plants by activation of a florigen gene in Arabidopsis. Next, we demonstrate accelerated regeneration and propagation of genome-edited plants by activation of morphogenic genes in poplar. Furthermore, we apply CRISPR-Combo to achieve rice regeneration without exogenous plant hormones, which is established as a new method to predominately enrich heritable targeted mutations. In conclusion, CRISPR-Combo is a versatile genome engineering tool with promising applications in crop breeding.
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Affiliation(s)
- Changtian Pan
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Gen Li
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Aimee A Malzahn
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Yanhao Cheng
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Benjamin Leyson
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Simon Sretenovic
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Filiz Gurel
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
| | - Gary D Coleman
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA
| | - Yiping Qi
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD, USA.
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD, USA.
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46
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Huang H, Huang G, Tan Z, Hu Y, Shan L, Zhou J, Zhang X, Ma S, Lv W, Huang T, Liu Y, Wang D, Zhao X, Lin Y, Rong Z. Engineered Cas12a-Plus nuclease enables gene editing with enhanced activity and specificity. BMC Biol 2022; 20:91. [PMID: 35468792 PMCID: PMC9040236 DOI: 10.1186/s12915-022-01296-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 04/12/2022] [Indexed: 11/23/2022] Open
Abstract
Background The CRISPR-Cas12a (formerly Cpf1) system is a versatile gene-editing tool with properties distinct from the broadly used Cas9 system. Features such as recognition of T-rich protospacer-adjacent motif (PAM) and generation of sticky breaks, as well as amenability for multiplex editing in a single crRNA and lower off-target nuclease activity, broaden the targeting scope of available tools and enable more accurate genome editing. However, the widespread use of the nuclease for gene editing, especially in clinical applications, is hindered by insufficient activity and specificity despite previous efforts to improve the system. Currently reported Cas12a variants achieve high activity with a compromise of specificity. Here, we used structure-guided protein engineering to improve both editing efficiency and targeting accuracy of Acidaminococcus sp. Cas12a (AsCas12a) and Lachnospiraceae bacterium Cas12a (LbCas12a). Results We created new AsCas12a variant termed “AsCas12a-Plus” with increased activity (1.5~2.0-fold improvement) and specificity (reducing off-targets from 29 to 23 and specificity index increased from 92% to 94% with 33 sgRNAs), and this property was retained in multiplex editing and transcriptional activation. When used to disrupt the oncogenic BRAFV600E mutant, AsCas12a-Plus showed less off-target activity while maintaining comparable editing efficiency and BRAFV600E cancer cell killing. By introducing the corresponding substitutions into LbCas12a, we also generated LbCas12a-Plus (activity improved ~1.1-fold and off-targets decreased from 20 to 12 while specificity index increased from 78% to 89% with 15 sgRNAs), suggesting this strategy may be generally applicable across Cas12a orthologs. We compared Cas12a-Plus, other variants described in this study, and the reported enCas12a-HF, enCas12a, and Cas12a-ultra, and found that Cas12a-Plus outperformed other variants with a good balance for enhanced activity and improved specificity. Conclusions Our discoveries provide alternative AsCas12a and LbCas12a variants with high specificity and activity, which expand the gene-editing toolbox and can be more suitable for clinical applications. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01296-1.
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Affiliation(s)
- Hongxin Huang
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China
| | - Guanjie Huang
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Zhihong Tan
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Yongfei Hu
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China.,Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Lin Shan
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Jiajian Zhou
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China
| | - Xin Zhang
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Shufeng Ma
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Weiqi Lv
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China
| | - Tao Huang
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China.,Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Yuchen Liu
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China
| | - Dong Wang
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China.,Department of Bioinformatics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Xiaoyang Zhao
- Department of Development, School of Basic Medical Sciences, Southern Medical University, Guangzhou, China
| | - Ying Lin
- Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China. .,Experimental Education/Administration Center, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Zhili Rong
- Dermatology Hospital, Southern Medical University, Guangzhou, 510091, China. .,Cancer Research Institute, School of Basic Medical Sciences, State Key Laboratory of Organ Failure Research, National Clinical Research Center of Kidney Disease, Key Laboratory of Organ Failure Research (Ministry of Education), Southern Medical University, Guangzhou, 510515, China. .,Experimental Education/Administration Center, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
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47
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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: 5] [Impact Index Per Article: 2.5] [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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48
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Yang S, Joesaar A, Bögels BWA, Mann S, Greef T. Protocellular CRISPR/Cas‐based Diffusive Communication Using Transcriptional RNA Signaling. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202202436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Shuo Yang
- Eindhoven University of Technology: Technische Universiteit Eindhoven Biomedical Engineering NETHERLANDS
| | - Alex Joesaar
- Eindhoven University of Technology: Technische Universiteit Eindhoven Biomedical Engineering NETHERLANDS
| | - Bas W. A. Bögels
- Eindhoven University of Technology: Technische Universiteit Eindhoven Biomedical Engineering NETHERLANDS
| | - Stephen Mann
- Bristol University School of Chemistry UNITED KINGDOM
| | - Tom Greef
- Eindhoven University of Technology Den Dolech 2CE 1.44B 5612 AZ Eindhoven NETHERLANDS
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49
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A tweak and a peek: How Cas9 pries open double-stranded DNA to check its sequence. Nat Struct Mol Biol 2022; 29:286-288. [PMID: 35422517 DOI: 10.1038/s41594-022-00763-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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50
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Improving the specificity of nucleic acid detection with endonuclease-actuated degradation. Commun Biol 2022; 5:290. [PMID: 35361863 PMCID: PMC8971390 DOI: 10.1038/s42003-022-03242-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Accepted: 03/07/2022] [Indexed: 11/08/2022] Open
Abstract
Nucleic acid detection is essential for numerous biomedical applications, but often requires complex protocols and/or suffers false-positive readouts. Here, we describe SENTINEL, an approach that combines isothermal amplification with a sequence-specific degradation method to detect nucleic acids with high sensitivity and sequence-specificity. Target single-stranded RNA or double-stranded DNA molecules are amplified by loop-mediated isothermal amplification (LAMP) and subsequently degraded by the combined action of lambda exonuclease and a sequence-specific DNA endonuclease (e.g., Cas9). By combining the sensitivity of LAMP with the precision of DNA endonucleases, the protocol achieves attomolar limits of detection while differentiating between sequences that differ by only one or two base pairs. The protocol requires less than an hour to complete using a 65 °C heat block and fluorometer, and detects SARS-CoV-2 virus particles in human saliva and nasopharyngeal swabs with high sensitivity.
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