1
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Fu S, Li J, Chen J, Zhang L, Liu J, Liu H, Su X. Bacteriophage λ exonuclease and a 5'-phosphorylated DNA guide allow PAM-independent targeting of double-stranded nucleic acids. Nat Biotechnol 2024:10.1038/s41587-024-02388-9. [PMID: 39294394 DOI: 10.1038/s41587-024-02388-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 08/19/2024] [Indexed: 09/20/2024]
Abstract
Sequence-specific recognition of double-stranded nucleic acids is essential for molecular diagnostics and in situ imaging. Clustered regularly interspaced short palindromic repeats and Cas systems rely on protospacer-adjacent motif (PAM)-dependent double-stranded DNA (dsDNA) recognition, limiting the range of targetable sequences and leading to undesired off-target effects. Using single-molecule fluorescence resonance energy transfer analysis, we discover the enzymatic activity of bacteriophage λ exonuclease (λExo). We show binding of 5'-phosphorylated single-stranded DNA (pDNA) to complementary regions on dsDNA and DNA-RNA duplexes, without the need for a PAM-like motif. Upon binding, the λExo-pDNA system catalytically digests the pDNA into nucleotides in the presence of Mg2+. This process is sensitive to mismatches within a wide range of the pDNA-binding region, resulting in exceptional sequence specificity and reduced off-target effects in various applications. The absence of a requirement for a specific motif such as a PAM sequence greatly broadens the range of targets. We demonstrate that the λExo-pDNA system is a versatile tool for molecular diagnostics, DNA computing and gene imaging applications.
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Affiliation(s)
- Shengnan Fu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Junjie Li
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Jing Chen
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Linghao Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Jiajia Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Huiyu Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - Xin Su
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering and State Key Laboratory of Organic-Inorganic Composites, Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China.
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2
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Vercauteren S, Fiesack S, Maroc L, Verstraeten N, Dewachter L, Michiels J, Vonesch SC. The rise and future of CRISPR-based approaches for high-throughput genomics. FEMS Microbiol Rev 2024; 48:fuae020. [PMID: 39085047 PMCID: PMC11409895 DOI: 10.1093/femsre/fuae020] [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: 05/08/2024] [Revised: 07/19/2024] [Accepted: 07/30/2024] [Indexed: 08/02/2024] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) has revolutionized the field of genome editing. To circumvent the permanent modifications made by traditional CRISPR techniques and facilitate the study of both essential and nonessential genes, CRISPR interference (CRISPRi) was developed. This gene-silencing technique employs a deactivated Cas effector protein and a guide RNA to block transcription initiation or elongation. Continuous improvements and a better understanding of the mechanism of CRISPRi have expanded its scope, facilitating genome-wide high-throughput screens to investigate the genetic basis of phenotypes. Additionally, emerging CRISPR-based alternatives have further expanded the possibilities for genetic screening. This review delves into the mechanism of CRISPRi, compares it with other high-throughput gene-perturbation techniques, and highlights its superior capacities for studying complex microbial traits. We also explore the evolution of CRISPRi, emphasizing enhancements that have increased its capabilities, including multiplexing, inducibility, titratability, predictable knockdown efficacy, and adaptability to nonmodel microorganisms. Beyond CRISPRi, we discuss CRISPR activation, RNA-targeting CRISPR systems, and single-nucleotide resolution perturbation techniques for their potential in genome-wide high-throughput screens in microorganisms. Collectively, this review gives a comprehensive overview of the general workflow of a genome-wide CRISPRi screen, with an extensive discussion of strengths and weaknesses, future directions, and potential alternatives.
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Affiliation(s)
- Silke Vercauteren
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Simon Fiesack
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Laetitia Maroc
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Natalie Verstraeten
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Liselot Dewachter
- de Duve Institute, Université catholique de Louvain, Hippokrateslaan 75, 1200 Brussels, Belgium
| | - Jan Michiels
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
| | - Sibylle C Vonesch
- Center for Microbiology, VIB - KU Leuven, Gaston Geenslaan 1, 3001 Leuven, Belgium
- Centre of Microbial and Plant Genetics, KU Leuven, Kasteelpark Arenberg 20, box 2460, 3001 Leuven, Belgium
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3
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Kumar A, Daripa P, Rasool K, Chakraborty D, Jain N, Maiti S. Deciphering the Thermodynamic Landscape of CRISPR/Cas9: Insights into Enhancing Gene Editing Precision and Efficiency. J Phys Chem B 2024; 128:8409-8422. [PMID: 39190773 DOI: 10.1021/acs.jpcb.4c04044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2024]
Abstract
The thermodynamic landscape of the CRISPR/Cas9 system plays a crucial role in understanding and optimizing the performance of this revolutionary genome-editing technology. In this research, we utilized isothermal titration calorimetry and microscale thermophoresis techniques to thoroughly investigate the thermodynamic properties governing CRISPR/Cas9 interactions. Our findings revealed that the binding between sgRNA and Cas9 is primarily governed by entropy, which compensates for an unfavorable enthalpy change. Conversely, the interaction between the CRISPR RNP complex and the target DNA is characterized by a favorable enthalpy change, offsetting an unfavorable entropy change. Notably, both interactions displayed negative heat capacity changes, indicative of potential hydration, ionization, or structural rearrangements. However, we noted that the involvement of water molecules and counterions in the interactions is minimal, suggesting that structural rearrangements play a significant role in influencing the binding thermodynamics. These results offer a nuanced understanding of the energetic contributions and structural dynamics underlying CRISPR-mediated gene editing. Such insights are invaluable for optimizing the efficiency and specificity of CRISPR-based genome editing applications, ultimately advancing our ability to precisely manipulate genetic material in various organisms for research, therapeutic, and biotechnological purposes.
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Affiliation(s)
- Ajit Kumar
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Purba Daripa
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India
| | - Kaiser Rasool
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India
| | - Debojyoti Chakraborty
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Niyati Jain
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Souvik Maiti
- CSIR-Institute of Genomics & Integrative Biology, New Delhi 110025, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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4
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Aguirre Rivera J, Mao G, Sabantsev A, Panfilov M, Hou Q, Lindell M, Chanez C, Ritort F, Jinek M, Deindl S. Massively parallel analysis of single-molecule dynamics on next-generation sequencing chips. Science 2024; 385:892-898. [PMID: 39172826 DOI: 10.1126/science.adn5371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 06/12/2024] [Indexed: 08/24/2024]
Abstract
Single-molecule techniques are ideally poised to characterize complex dynamics but are typically limited to investigating a small number of different samples. However, a large sequence or chemical space often needs to be explored to derive a comprehensive understanding of complex biological processes. Here we describe multiplexed single-molecule characterization at the library scale (MUSCLE), a method that combines single-molecule fluorescence microscopy with next-generation sequencing to enable highly multiplexed observations of complex dynamics. We comprehensively profiled the sequence dependence of DNA hairpin properties and Cas9-induced target DNA unwinding-rewinding dynamics. The ability to explore a large sequence space for Cas9 allowed us to identify a number of target sequences with unexpected behaviors. We envision that MUSCLE will enable the mechanistic exploration of many fundamental biological processes.
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Affiliation(s)
- J Aguirre Rivera
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75105 Uppsala, Sweden
| | - G Mao
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75105 Uppsala, Sweden
| | - A Sabantsev
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75105 Uppsala, Sweden
| | - M Panfilov
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75105 Uppsala, Sweden
| | - Q Hou
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75105 Uppsala, Sweden
| | - M Lindell
- Department of Medical Sciences, Science for Life Laboratory, Uppsala University, 75144 Uppsala, Sweden
| | - C Chanez
- Department of Biochemistry, University of Zürich, 8057 Zürich, Switzerland
| | - F Ritort
- Small Biosystems Lab, Condensed Matter Physics Department, Universitat de Barcelona, 08028 Barcelona, Spain
- Institut de Nanociència i Nanotecnologia (IN2UB), Universitat de Barcelona, 08028 Barcelona, Spain
| | - M Jinek
- Department of Biochemistry, University of Zürich, 8057 Zürich, Switzerland
| | - S Deindl
- Department of Cell and Molecular Biology, Science for Life Laboratory, Uppsala University, 75105 Uppsala, Sweden
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5
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Medd MM, Cao Q. Perspectives on CRISPR Genome Editing to Prevent Prion Diseases in High-Risk Individuals. Biomedicines 2024; 12:1725. [PMID: 39200190 PMCID: PMC11352000 DOI: 10.3390/biomedicines12081725] [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: 07/01/2024] [Revised: 07/24/2024] [Accepted: 07/30/2024] [Indexed: 09/02/2024] Open
Abstract
Prion diseases are neurodegenerative disorders caused by misfolded prion proteins. Although rare, the said diseases are always fatal; they commonly cause death within months of developing clinical symptoms, and their diagnosis is exceptionally difficult pre-mortem. There are no known cures or treatments other than symptomatic care. Given the aggressiveness of prion diseases on onset, therapies after disease onset could be challenging. Prevention to reduce the incidence or to delay the disease onset has been suggested to be a more feasible approach. In this perspective article, we summarize our current understandings of the origin, risk factors, and clinical manifestations of prion diseases. We propose a PCR testing of the blood to identify PRNP gene polymorphisms at codons 129 and 127 in individuals with familial PRNP mutations to assess the risk. We further present the CRISPR/Cas9 gene editing strategy as a perspective preventative approach for these high-risk individuals to induce a polymorphic change at codon 127 of the PRNP gene, granting immunity to prion diseases in selected high-risk individuals, in particular, in individuals with familial PRNP mutations.
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Affiliation(s)
- Milan M. Medd
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Qi Cao
- Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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6
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Reginato G, Dello Stritto MR, Wang Y, Hao J, Pavani R, Schmitz M, Halder S, Morin V, Cannavo E, Ceppi I, Braunshier S, Acharya A, Ropars V, Charbonnier JB, Jinek M, Nussenzweig A, Ha T, Cejka P. HLTF disrupts Cas9-DNA post-cleavage complexes to allow DNA break processing. Nat Commun 2024; 15:5789. [PMID: 38987539 PMCID: PMC11237066 DOI: 10.1038/s41467-024-50080-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 06/28/2024] [Indexed: 07/12/2024] Open
Abstract
The outcome of CRISPR-Cas-mediated genome modifications is dependent on DNA double-strand break (DSB) processing and repair pathway choice. Homology-directed repair (HDR) of protein-blocked DSBs requires DNA end resection that is initiated by the endonuclease activity of the MRE11 complex. Using reconstituted reactions, we show that Cas9 breaks are unexpectedly not directly resectable by the MRE11 complex. In contrast, breaks catalyzed by Cas12a are readily processed. Cas9, unlike Cas12a, bridges the broken ends, preventing DSB detection and processing by MRE11. We demonstrate that Cas9 must be dislocated after DNA cleavage to allow DNA end resection and repair. Using single molecule and bulk biochemical assays, we next find that the HLTF translocase directly removes Cas9 from broken ends, which allows DSB processing by DNA end resection or non-homologous end-joining machineries. Mechanistically, the activity of HLTF requires its HIRAN domain and the release of the 3'-end generated by the cleavage of the non-target DNA strand by the Cas9 RuvC domain. Consequently, HLTF removes the H840A but not the D10A Cas9 nickase. The removal of Cas9 H840A by HLTF explains the different cellular impact of the two Cas9 nickase variants in human cells, with potential implications for gene editing.
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Affiliation(s)
- Giordano Reginato
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
| | - Maria Rosaria Dello Stritto
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
| | - Yanbo Wang
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, 21205, USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jingzhou Hao
- Department of Biophysics, Johns Hopkins University, Baltimore, MD21218, USA
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, 02115, USA
| | - Raphael Pavani
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Michael Schmitz
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Swagata Halder
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
- Biological Systems Engineering, Plaksha University, Mohali, Punjab, 140306, India
| | - Vincent Morin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Elda Cannavo
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
| | - Ilaria Ceppi
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
| | - Stefan Braunshier
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
| | - Ananya Acharya
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland
| | - Virginie Ropars
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Jean-Baptiste Charbonnier
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198, Gif-sur-Yvette, France
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zürich, Switzerland
| | - Andrè Nussenzweig
- Laboratory of Genome Integrity, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Taekjip Ha
- Department of Biophysics & Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, 21205, USA
- Department of Biophysics, Johns Hopkins University, Baltimore, MD21218, USA
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, 02115, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, 02115, USA
- Howard Hughes Medical Institute, Boston, MA, 02115, USA
| | - Petr Cejka
- Faculty of Biomedical Sciences, Institute for Research in Biomedicine, Università della Svizzera italiana (USI), 6500, Bellinzona, Switzerland.
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7
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Wang J, Wang K, Deng Z, Zhong Z, Sun G, Mei Q, Zhou F, Deng Z, Sun Y. Engineered cytosine base editor enabling broad-scope and high-fidelity gene editing in Streptomyces. Nat Commun 2024; 15:5687. [PMID: 38971862 PMCID: PMC11227558 DOI: 10.1038/s41467-024-49987-3] [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: 02/17/2024] [Accepted: 06/26/2024] [Indexed: 07/08/2024] Open
Abstract
Base editing (BE) faces protospacer adjacent motif (PAM) constraints and off-target effects in both eukaryotes and prokaryotes. For Streptomyces, renowned as one of the most prolific bacterial producers of antibiotics, the challenges are more pronounced due to its diverse genomic content and high GC content. Here, we develop a base editor named eSCBE3-NG-Hypa, tailored with both high efficiency and -fidelity for Streptomyces. Of note, eSCBE3-NG-Hypa recognizes NG PAM and exhibits high activity at challenging sites with high GC content or GC motifs, while displaying minimal off-target effects. To illustrate its practicability, we employ eSCBE3-NG-Hypa to achieve precise key amino acid conversion of the dehydratase (DH) domains within the modular polyketide synthase (PKS) responsible for the insecticide avermectins biosynthesis, achieving domains inactivation. The resulting DH-inactivated mutants, while ceasing avermectins production, produce a high yield of oligomycin, indicating competitive relationships among multiple biosynthetic gene clusters (BGCs) in Streptomyces avermitilis. Leveraging this insight, we use eSCBE3-NG-Hypa to introduce premature stop codons into competitor gene cluster of ave in an industrial S. avermitilis, with the mutant Δolm exhibiting the highest 4.45-fold increase in avermectin B1a compared to the control. This work provides a potent tool for modifying biosynthetic pathways and advancing metabolic engineering in Streptomyces.
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Affiliation(s)
- Jian Wang
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Ke Wang
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Zhe Deng
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Zhiyu Zhong
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Guo Sun
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Qing Mei
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Fuling Zhou
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Zixin Deng
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yuhui Sun
- Department of Hematology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China.
- School of Pharmacy, Huazhong University of Science and Technology, Wuhan, 430030, China.
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8
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Olivi L, Bagchus C, Pool V, Bekkering E, Speckner K, Offerhaus H, Wu W, Depken M, Martens KA, Staals RJ, Hohlbein J. Live-cell imaging reveals the trade-off between target search flexibility and efficiency for Cas9 and Cas12a. Nucleic Acids Res 2024; 52:5241-5256. [PMID: 38647045 PMCID: PMC11109954 DOI: 10.1093/nar/gkae283] [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: 11/16/2023] [Revised: 03/25/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024] Open
Abstract
CRISPR-Cas systems have widely been adopted as genome editing tools, with two frequently employed Cas nucleases being SpyCas9 and LbCas12a. Although both nucleases use RNA guides to find and cleave target DNA sites, the two enzymes differ in terms of protospacer-adjacent motif (PAM) requirements, guide architecture and cleavage mechanism. In the last years, rational engineering led to the creation of PAM-relaxed variants SpRYCas9 and impLbCas12a to broaden the targetable DNA space. By employing their catalytically inactive variants (dCas9/dCas12a), we quantified how the protein-specific characteristics impact the target search process. To allow quantification, we fused these nucleases to the photoactivatable fluorescent protein PAmCherry2.1 and performed single-particle tracking in cells of Escherichia coli. From our tracking analysis, we derived kinetic parameters for each nuclease with a non-targeting RNA guide, strongly suggesting that interrogation of DNA by LbdCas12a variants proceeds faster than that of SpydCas9. In the presence of a targeting RNA guide, both simulations and imaging of cells confirmed that LbdCas12a variants are faster and more efficient in finding a specific target site. Our work demonstrates the trade-off of relaxing PAM requirements in SpydCas9 and LbdCas12a using a powerful framework, which can be applied to other nucleases to quantify their DNA target search.
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Affiliation(s)
- Lorenzo Olivi
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Cleo Bagchus
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, The Netherlands
| | - Victor Pool
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, The Netherlands
| | - Ezra Bekkering
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, The Netherlands
| | - Konstantin Speckner
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, The Netherlands
| | - Hidde Offerhaus
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Wen Y Wu
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Martin Depken
- Department of Bionanoscience, Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Koen J A Martens
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, The Netherlands
| | - Raymond H J Staals
- Laboratory of Microbiology, Wageningen University & Research, Wageningen, The Netherlands
| | - Johannes Hohlbein
- Laboratory of Biophysics, Wageningen University & Research, Wageningen, The Netherlands
- Microspectroscopy Research Facility, Wageningen University & Research, Wageningen, The Netherlands
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9
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Zhao S, Liu J, Zuo Z. Secondary Conformational Checkpoint in CRISPR-Cas9. J Chem Theory Comput 2024; 20:3440-3448. [PMID: 38625092 DOI: 10.1021/acs.jctc.4c00120] [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] [Indexed: 04/17/2024]
Abstract
A specific checkpoint between target DNA binding and cleavage primarily governs the precision of Cas9 gene editing. Although various CRISPR-Cas9 variants have been developed to improve DNA cleavage accuracy, we still lack a comprehensive understanding of how they work at the molecular level. Herein, we have focused on studying the late-stage conformational transitions of Cas9 and an evolved Cas9 mutant (evoCas9) that start from the precleavage state. Our submilliseconds of dynamic simulations reveal that the presence of base mismatches leads the HNH nuclease domain of Cas9 to alter its principal functional modes of motion, thereby impairing its conformational activation. This observation suggests the existence of a secondary conformational checkpoint that fine-tunes the final DNA cleavage activation. Remarkably, evoCas9 is prone to deviating from the normal activation pathway with base mismatches. This is characterized by a noticeable shift in the positioning of the HNH domain and a significantly perturbed allosteric communication network within the enzyme. Therefore, the mutations evolved in evoCas9 also reinforce the secondary checkpoint in addition to the previously identified primary checkpoint, collectively ensuring this variant's high gene-editing accuracy. This mechanism should also apply to other Cas9-guide RNA variants with enhanced fidelity.
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Affiliation(s)
- Shuxin Zhao
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
- Shanghai Frontiers Science Research Center for Druggability of Cardiovascular noncoding RNA, Institute for Frontier Medical Technology, Shanghai University of Engineering Science, Shanghai 201620, China
| | - Jin Liu
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - Zhicheng Zuo
- College of Chemistry and Chemical Engineering, Shanghai University of Engineering Science, Shanghai 201620, China
- Shanghai Frontiers Science Research Center for Druggability of Cardiovascular noncoding RNA, Institute for Frontier Medical Technology, Shanghai University of Engineering Science, Shanghai 201620, China
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10
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Zhang F, Wang JY, Li CL, Zhang WG. HyCas9-12aGEP: an efficient genome editing platform for Corynebacterium glutamicum. Front Bioeng Biotechnol 2024; 12:1327172. [PMID: 38532881 PMCID: PMC10963414 DOI: 10.3389/fbioe.2024.1327172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 02/27/2024] [Indexed: 03/28/2024] Open
Abstract
Corynebacterium glutamicum plays a crucial role as a significant industrial producer of metabolites. Despite the successful development of CRISPR-Cas9 and CRISPR-Cas12a-assisted genome editing technologies in C. glutamicum, their editing resolution and efficiency are hampered by the diverse on-target activities of guide RNAs (gRNAs). To address this problem, a hybrid CRISPR-Cas9-Cas12a genome editing platform (HyCas9-12aGEP) was developed in C. glutamicum in this study to co-express sgRNA (corresponding to SpCas9 guide RNA), crRNA (corresponding to FnCas12a guide RNA), or hfgRNA (formed by the fusion of sgRNA and crRNA). HyCas9-12aGEP improves the efficiency of mapping active gRNAs and outperforms both CRISPR-Cas9 and CRISPR-Cas12a in genome editing resolution and efficiency. In the experiment involving the deletion of the cg0697-0740 gene segment, an unexpected phenotype was observed, and HyCas9-12aGEP efficiently identified the responsible genotype from more than 40 genes. Here, HyCas9-12aGEP greatly improve our capability in terms of genome reprogramming in C. glutamicum.
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Affiliation(s)
- Feng Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
| | | | | | - Wei-Guo Zhang
- The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, China
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11
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Skeens E, Sinha S, Ahsan M, D’Ordine AM, Jogl G, Palermo G, Lisi GP. High-fidelity, hyper-accurate, and evolved mutants rewire atomic-level communication in CRISPR-Cas9. SCIENCE ADVANCES 2024; 10:eadl1045. [PMID: 38446895 PMCID: PMC10917355 DOI: 10.1126/sciadv.adl1045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 01/29/2024] [Indexed: 03/08/2024]
Abstract
The high-fidelity (HF1), hyper-accurate (Hypa), and evolved (Evo) variants of the CRISPR-associated protein 9 (Cas9) endonuclease are critical tools to mitigate off-target effects in the application of CRISPR-Cas9 technology. The mechanisms by which mutations in recognition subdomain 3 (Rec3) mediate specificity in these variants are poorly understood. Here, solution nuclear magnetic resonance and molecular dynamics simulations establish the structural and dynamic effects of high-specificity mutations in Rec3, and how they propagate the allosteric signal of Cas9. We reveal conserved structural changes and dynamic differences at regions of Rec3 that interface with the RNA:DNA hybrid, transducing chemical signals from Rec3 to the catalytic His-Asn-His (HNH) domain. The variants remodel the communication sourcing from the Rec3 α helix 37, previously shown to sense target DNA complementarity, either directly or allosterically. This mechanism increases communication between the DNA mismatch recognition helix and the HNH active site, shedding light on the structure and dynamics underlying Cas9 specificity and providing insight for future engineering principles.
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Affiliation(s)
- Erin Skeens
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Souvik Sinha
- Department of Bioengineering, University of California, Riverside, Riverside, CA, USA
| | - Mohd Ahsan
- Department of Bioengineering, University of California, Riverside, Riverside, CA, USA
| | - Alexandra M. D’Ordine
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Gerwald Jogl
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, Riverside, CA, USA
- Department of Chemistry, University of California, Riverside, Riverside, CA, USA
| | - George P. Lisi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, RI, USA
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12
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Devarajan A. Optically Controlled CRISPR-Cas9 and Cre Recombinase for Spatiotemporal Gene Editing: A Review. ACS Synth Biol 2024; 13:25-44. [PMID: 38134336 DOI: 10.1021/acssynbio.3c00596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
CRISPR-Cas9 and Cre recombinase, two tools extensively used for genome interrogation, have catalyzed key breakthroughs in our understanding of complex biological processes and diseases. However, the immense complexity of biological systems and off-target effects hinder clinical applications, necessitating the development of platforms to control gene editing over spatial and temporal dimensions. Among the strategies developed for inducible control, light is particularly attractive as it is noninvasive and affords high spatiotemporal resolution. The principles for optical control of Cas9 and Cre recombinase are broadly similar and involve photocaged enzymes and small molecules, engineered split- and single-chain constructs, light-induced expression, and delivery by light-responsive nanocarriers. Few systems enable spatiotemporal control with a high dynamic range without loss of wild-type editing efficiencies. Such systems posit the promise of light-activatable systems in the clinic. While the prospect of clinical applications is palpably exciting, optimization and extensive preclinical validation are warranted. Judicious integration of optically activated CRISPR and Cre, tailored for the desired application, may help to bridge the "bench-to-bedside" gap in therapeutic gene editing.
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Affiliation(s)
- Archit Devarajan
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal, Madhya Pradesh, India - 462066
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13
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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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14
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Zhou B, Chen Y, Li L, Liu J, Wang Y, Huang Z, Hu Z, Tian R, Li Z. Purification and functional validation of LtCas12a protein. STAR Protoc 2023; 4:102600. [PMID: 37768827 PMCID: PMC10550837 DOI: 10.1016/j.xpro.2023.102600] [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: 05/18/2023] [Revised: 06/29/2023] [Accepted: 09/05/2023] [Indexed: 09/30/2023] Open
Abstract
Here, we present a protocol for generating LtCas12a protein recognizing distinct TTNA (N represented A, T, C, G) protospacer adjacent motif sequence. We describe steps for transforming and harvesting bacterial cells and protein purification including nickel affinity chromatography and dialysis. We then detail procedures for verification of LtCas12a with cis- and trans-cleavage activities. For complete details on the use and execution of this protocol, please refer to Chen et al. (2023).1.
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Affiliation(s)
- Bo Zhou
- Department of Gynecological Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430062, Hubei, China; Women and Children's Hospital Affiliated to Zhongnan Hospital of Wuhan University, Wuhan 430062, Hubei, China
| | - Ye Chen
- Department of Gynecological Oncology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
| | - Lifang Li
- Department of Gynecological Oncology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
| | - Jiashuo Liu
- Department of Gynecological Oncology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
| | - Yuyan Wang
- Department of Gynecological Oncology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
| | - Zheying Huang
- Department of Gynecological Oncology, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, Guangdong, China
| | - Zheng Hu
- Department of Gynecological Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430062, Hubei, China; Women and Children's Hospital Affiliated to Zhongnan Hospital of Wuhan University, Wuhan 430062, Hubei, China.
| | - Rui Tian
- Generulor Company Bio-X Lab, Zhuhai 519000, Guangdong, China.
| | - Zhen Li
- Department of Gynecological Oncology, Zhongnan Hospital of Wuhan University, Wuhan 430062, Hubei, China; Women and Children's Hospital Affiliated to Zhongnan Hospital of Wuhan University, Wuhan 430062, Hubei, China.
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15
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Maghsoud Y, Jayasinghe-Arachchige VM, Kumari P, Cisneros GA, Liu J. Leveraging QM/MM and Molecular Dynamics Simulations to Decipher the Reaction Mechanism of the Cas9 HNH Domain to Investigate Off-Target Effects. J Chem Inf Model 2023; 63:6834-6850. [PMID: 37877218 DOI: 10.1021/acs.jcim.3c01284] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
The clustered regularly interspaced short palindromic repeats (CRISPR) technology is an RNA-guided targeted genome-editing tool using Cas family proteins. Two magnesium-dependent nuclease domains of the Cas9 enzyme, termed HNH and RuvC, are responsible for cleaving the target DNA (t-DNA) and nontarget DNA strands, respectively. The HNH domain is believed to determine the DNA cleavage activity of both endonuclease domains and is sensitive to complementary RNA-DNA base pairing. However, the underlying molecular mechanisms of CRISPR-Cas9, by which it rebukes or accepts mismatches, are poorly understood. Thus, investigation of the structure and dynamics of the catalytic state of Cas9 with either matched or mismatched t-DNA can provide insights into improving its specificity by reducing off-target cleavages. Here, we focus on a recently discovered catalytic-active form of the Streptococcus pyogenes Cas9 (SpCas9) and employ classical molecular dynamics and coupled quantum mechanics/molecular mechanics simulations to study two possible mechanisms of t-DNA cleavage reaction catalyzed by the HNH domain. Moreover, by designing a mismatched t-DNA structure called MM5 (C to G at the fifth position from the protospacer adjacent motif region), the impact of single-guide RNA (sgRNA) and t-DNA complementarity on the catalysis process was investigated. Based on these simulations, our calculated binding affinities, minimum energy paths, and analysis of catalytically important residues provide atomic-level details of the differences between matched and mismatched cleavage reactions. In addition, several residues exhibit significant differences in their catalytic roles for the two studied systems, including K253, K263, R820, K896, and K913.
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Affiliation(s)
- Yazdan Maghsoud
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Vindi M Jayasinghe-Arachchige
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - Pratibha Kumari
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
| | - G Andrés Cisneros
- Department of Chemistry and Biochemistry, University of Texas at Dallas, Richardson, Texas 75080, United States
- Department of Physics, University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jin Liu
- Department of Pharmaceutical Sciences, University of North Texas System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, Texas 76107, United States
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16
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Zhang YR, Yin TL, Zhou LQ. CRISPR/Cas9 technology: applications in oocytes and early embryos. J Transl Med 2023; 21:746. [PMID: 37875936 PMCID: PMC10594749 DOI: 10.1186/s12967-023-04610-9] [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: 07/12/2023] [Accepted: 10/09/2023] [Indexed: 10/26/2023] Open
Abstract
CRISPR/Cas9, a highly versatile genome-editing tool, has garnered significant attention in recent years. Despite the unique characteristics of oocytes and early embryos compared to other cell types, this technology has been increasing used in mammalian reproduction. In this comprehensive review, we elucidate the fundamental principles of CRISPR/Cas9-related methodologies and explore their wide-ranging applications in deciphering molecular intricacies during oocyte and early embryo development as well as in addressing associated diseases. However, it is imperative to acknowledge the limitations inherent to these technologies, including the potential for off-target effects, as well as the ethical concerns surrounding the manipulation of human embryos. Thus, a judicious and thoughtful approach is warranted. Regardless of these challenges, CRISPR/Cas9 technology undeniably represents a formidable tool for genome and epigenome manipulation within oocytes and early embryos. Continuous refinements in this field are poised to fortify its future prospects and applications.
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Affiliation(s)
- Yi-Ran Zhang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Tai-Lang Yin
- Reproductive Medical Center, Renmin Hospital of Wuhan University & Hubei Clinic Research Center for Assisted Reproductive Technology and Embryonic Development, Wuhan, China.
| | - Li-Quan Zhou
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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17
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Newton MD, Losito M, Smith QM, Parnandi N, Taylor BJ, Akcakaya P, Maresca M, van Eijk P, Reed SH, Boulton SJ, King GA, Cuomo ME, Rueda DS. Negative DNA supercoiling induces genome-wide Cas9 off-target activity. Mol Cell 2023; 83:3533-3545.e5. [PMID: 37802026 DOI: 10.1016/j.molcel.2023.09.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 05/30/2023] [Accepted: 09/07/2023] [Indexed: 10/08/2023]
Abstract
CRISPR-Cas9 is a powerful gene-editing technology; however, off-target activity remains an important consideration for therapeutic applications. We have previously shown that force-stretching DNA induces off-target activity and hypothesized that distortions of the DNA topology in vivo, such as negative DNA supercoiling, could reduce Cas9 specificity. Using single-molecule optical-tweezers, we demonstrate that negative supercoiling λ-DNA induces sequence-specific Cas9 off-target binding at multiple sites, even at low forces. Using an adapted CIRCLE-seq approach, we detect over 10,000 negative-supercoiling-induced Cas9 off-target double-strand breaks genome-wide caused by increased mismatch tolerance. We further demonstrate in vivo that directed local DNA distortion increases off-target activity in cells and that induced off-target events can be detected during Cas9 genome editing. These data demonstrate that Cas9 off-target activity is regulated by DNA topology in vitro and in vivo, suggesting that cellular processes, such as transcription and replication, could induce off-target activity at previously overlooked sites.
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Affiliation(s)
- Matthew D Newton
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0HS, UK; Single Molecule Imaging, MRC-London Institute of Medical Sciences, Du Cane Road, London W12 0HS, UK; DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Marialucrezia Losito
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0HS, UK; Single Molecule Imaging, MRC-London Institute of Medical Sciences, Du Cane Road, London W12 0HS, UK; Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB2 0AA, UK
| | - Quentin M Smith
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0HS, UK; Single Molecule Imaging, MRC-London Institute of Medical Sciences, Du Cane Road, London W12 0HS, UK
| | - Nishita Parnandi
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Benjamin J Taylor
- Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, Cambridge CB2 0AA, UK
| | - Pinar Akcakaya
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, 43183 Gothenburg, Sweden
| | - Marcello Maresca
- Genome Engineering, Discovery Sciences, BioPharmaceuticals R&D, AstraZeneca, 43183 Gothenburg, Sweden
| | - Patrick van Eijk
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff CF14 4AW, UK
| | - Simon H Reed
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff CF14 4AW, UK
| | - Simon J Boulton
- DSB Repair Metabolism Laboratory, The Francis Crick Institute, London NW1 1AT, UK
| | - Graeme A King
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK.
| | | | - David S Rueda
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0HS, UK; Single Molecule Imaging, MRC-London Institute of Medical Sciences, Du Cane Road, London W12 0HS, UK.
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18
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Kulcsár PI, Tálas A, Ligeti Z, Tóth E, Rakvács Z, Bartos Z, Krausz SL, Welker Á, Végi VL, Huszár K, Welker E. A cleavage rule for selection of increased-fidelity SpCas9 variants with high efficiency and no detectable off-targets. Nat Commun 2023; 14:5746. [PMID: 37717069 PMCID: PMC10505190 DOI: 10.1038/s41467-023-41393-5] [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: 08/08/2022] [Accepted: 09/04/2023] [Indexed: 09/18/2023] Open
Abstract
Streptococcus pyogenes Cas9 (SpCas9) has been employed as a genome engineering tool with a promising potential within therapeutics. However, its off-target effects present major safety concerns for applications requiring high specificity. Approaches developed to date to mitigate this effect, including any of the increased-fidelity (i.e., high-fidelity) SpCas9 variants, only provide efficient editing on a relatively small fraction of targets without detectable off-targets. Upon addressing this problem, we reveal a rather unexpected cleavability ranking of target sequences, and a cleavage rule that governs the on-target and off-target cleavage of increased-fidelity SpCas9 variants but not that of SpCas9-NG or xCas9. According to this rule, for each target, an optimal variant with matching fidelity must be identified for efficient cleavage without detectable off-target effects. Based on this insight, we develop here an extended set of variants, the CRISPRecise set, with increased fidelity spanning across a wide range, with differences in fidelity small enough to comprise an optimal variant for each target, regardless of its cleavability ranking. We demonstrate efficient editing with maximum specificity even on those targets that have not been possible in previous studies.
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Affiliation(s)
- Péter István Kulcsár
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - András Tálas
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Zoltán Ligeti
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
- Doctoral School of Multidisciplinary Medical Science, University of Szeged, Szeged, Hungary
| | - Eszter Tóth
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Zsófia Rakvács
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Zsuzsa Bartos
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Sarah Laura Krausz
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
- Biospiral-2006 Ltd, Szeged, Hungary
- School of Ph.D. Studies, Semmelweis University, Budapest, Hungary
| | - Ágnes Welker
- Institute of Cognitive Neuroscience and Psychology, Research Centre for Natural Sciences, Budapest, Hungary
- Gene Design Ltd, Szeged, Hungary
| | - Vanessza Laura Végi
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
- Biospiral-2006 Ltd, Szeged, Hungary
| | - Krisztina Huszár
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
- Gene Design Ltd, Szeged, Hungary
| | - Ervin Welker
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary.
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary.
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19
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Chu J, Romero A, Taulbee J, Aran K. Development of Single Molecule Techniques for Sensing and Manipulation of CRISPR and Polymerase Enzymes. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2300328. [PMID: 37226388 PMCID: PMC10524706 DOI: 10.1002/smll.202300328] [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] [Received: 01/11/2023] [Revised: 03/20/2023] [Indexed: 05/26/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and polymerases are powerful enzymes and their diverse applications in genomics, proteomics, and transcriptomics have revolutionized the biotechnology industry today. CRISPR has been widely adopted for genomic editing applications and Polymerases can efficiently amplify genomic transcripts via polymerase chain reaction (PCR). Further investigations into these enzymes can reveal specific details about their mechanisms that greatly expand their use. Single-molecule techniques are an effective way to probe enzymatic mechanisms because they may resolve intermediary conformations and states with greater detail than ensemble or bulk biosensing techniques. This review discusses various techniques for sensing and manipulation of single biomolecules that can help facilitate and expedite these discoveries. Each platform is categorized as optical, mechanical, or electronic. The methods, operating principles, outputs, and utility of each technique are briefly introduced, followed by a discussion of their applications to monitor and control CRISPR and Polymerases at the single molecule level, and closing with a brief overview of their limitations and future prospects.
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Affiliation(s)
- Josephine Chu
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Andres Romero
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Jeffrey Taulbee
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
| | - Kiana Aran
- Henry E. Riggs School of Applied Life Sciences, Keck Graduate Institute, Claremont, CA, 91711, USA
- Cardea, San Diego, CA, 92121, USA
- University of California Berkeley, Berkeley, CA, 94720, USA
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20
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Skeens E, Sinha S, Ahsan M, D'Ordine AM, Jogl G, Palermo G, Lisi GP. High-Fidelity, Hyper-Accurate, and Evolved Mutants Rewire Atomic Level Communication in CRISPR-Cas9. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.25.554853. [PMID: 37662375 PMCID: PMC10473742 DOI: 10.1101/2023.08.25.554853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
The Cas9-HF1, HypaCas9, and evoCas9 variants of the Cas9 endonuclease are critical tools to mitigate off-target effects in the application of CRISPR-Cas9 technology. The mechanisms by which mutations in the Rec3 domain mediate specificity in these variants are poorly understood. Here, solution NMR and molecular dynamics simulations establish the structural and dynamic effects of high-specificity mutations in Rec3, and how they propagate the allosteric signal of Cas9. We reveal conserved structural changes and peculiar dynamic differences at regions of Rec3 that interface with the RNA:DNA hybrid, transducing chemical signals from Rec3 to the catalytic HNH domain. The variants remodel the communication sourcing from the Rec3 α-helix 37, previously shown to sense target DNA complementarity, either directly or allosterically. This mechanism increases communication between the DNA mismatch recognition helix and the HNH active site, shedding light on the structure and dynamics underlying Cas9 specificity and providing insight for future engineering principles.
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21
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Kauert DJ, Madariaga-Marcos J, Rutkauskas M, Wulfken A, Songailiene I, Sinkunas T, Siksnys V, Seidel R. The energy landscape for R-loop formation by the CRISPR-Cas Cascade complex. Nat Struct Mol Biol 2023:10.1038/s41594-023-01019-2. [PMID: 37415009 DOI: 10.1038/s41594-023-01019-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/11/2023] [Indexed: 07/08/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) sequences and CRISPR-associated (Cas) genes comprise CIRSPR-Cas effector complexes, which have revolutionized gene editing with their ability to target specific genomic loci using CRISPR RNA (crRNA) complementarity. Recognition of double-stranded DNA targets proceeds via DNA unwinding and base pairing between crRNA and the DNA target strand, forming an R-loop structure. Full R-loop extension is a prerequisite for subsequent DNA cleavage. However, the recognition of unintended sequences with multiple mismatches has limited therapeutic applications and is still poorly understood on a mechanistic level. Here we set up ultrafast DNA unwinding experiments on the basis of plasmonic DNA origami nanorotors to study R-loop formation by the Cascade effector complex in real time, close to base-pair resolution. We resolve a weak global downhill bias of the forming R-loop, followed by a steep uphill bias for the final base pairs. We also show that the energy landscape is modulated by base flips and mismatches. These findings suggest that Cascade-mediated R-loop formation occurs on short timescales in submillisecond single base-pair steps, but on longer timescales in six base-pair intermediate steps, in agreement with the structural periodicity of the crRNA-DNA hybrid.
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Affiliation(s)
- Dominik J Kauert
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | | | - Marius Rutkauskas
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | - Alexander Wulfken
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany
| | - Inga Songailiene
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Tomas Sinkunas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Virginijus Siksnys
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius, Lithuania
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, Universität Leipzig, Leipzig, Germany.
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22
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Liu Y, Cottle WT, Ha T. Mapping cellular responses to DNA double-strand breaks using CRISPR technologies. Trends Genet 2023; 39:560-574. [PMID: 36967246 PMCID: PMC11062594 DOI: 10.1016/j.tig.2023.02.015] [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: 09/22/2021] [Revised: 02/23/2023] [Accepted: 02/24/2023] [Indexed: 06/15/2023]
Abstract
DNA double-strand breaks (DSBs) are one of the most genotoxic DNA lesions, driving a range of pathological defects from cancers to immunodeficiencies. To combat genomic instability caused by DSBs, evolution has outfitted cells with an intricate protein network dedicated to the rapid and accurate repair of these lesions. Pioneering studies have identified and characterized many crucial repair factors in this network, while the advent of genome manipulation tools like clustered regularly interspersed short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) has reinvigorated interest in DSB repair mechanisms. This review surveys the latest methodological advances and biological insights gained by utilizing Cas9 as a precise 'damage inducer' for the study of DSB repair. We highlight rapidly inducible Cas9 systems that enable synchronized and efficient break induction. When combined with sequencing and genome-specific imaging approaches, inducible Cas9 systems greatly expand our capability to spatiotemporally characterize cellular responses to DSB at specific genomic coordinates, providing mechanistic insights that were previously unobtainable.
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Affiliation(s)
- Yang Liu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - W Taylor Cottle
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA; Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA; Howard Hughes Medical Institute, Baltimore, MD, USA.
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23
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Kawamata M, Suzuki HI, Kimura R, Suzuki A. Optimization of Cas9 activity through the addition of cytosine extensions to single-guide RNAs. Nat Biomed Eng 2023; 7:672-691. [PMID: 37037965 DOI: 10.1038/s41551-023-01011-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/17/2023] [Indexed: 04/12/2023]
Abstract
The precise regulation of the activity of Cas9 is crucial for safe and efficient editing. Here we show that the genome-editing activity of Cas9 can be constrained by the addition of cytosine stretches to the 5'-end of conventional single-guide RNAs (sgRNAs). Such a 'safeguard sgRNA' strategy, which is compatible with Cas12a and with systems for gene activation and interference via CRISPR (clustered regularly interspaced short palindromic repeats), leads to the length-dependent inhibition of the formation of functional Cas9 complexes. Short cytosine extensions reduced p53 activation and cytotoxicity in human pluripotent stem cells, and enhanced homology-directed repair while maintaining bi-allelic editing. Longer extensions further decreased on-target activity yet improved the specificity and precision of mono-allelic editing. By monitoring indels through a fluorescence-based allele-specific system and computational simulations, we identified optimal windows of Cas9 activity for a number of genome-editing applications, including bi-allelic and mono-allelic editing, and the generation and correction of disease-associated single-nucleotide substitutions via homology-directed repair. The safeguard-sgRNA strategy may improve the safety and applicability of genome editing.
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Affiliation(s)
- Masaki Kawamata
- Division of Organogenesis and Regeneration, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
| | - Hiroshi I Suzuki
- Division of Molecular Oncology, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan.
- Institute for Glyco-core Research (iGCORE), Nagoya University, Nagoya, Japan.
- Center for One Medicine Innovative Translational Research, Gifu University Institute for Advanced Study, Gifu, Japan.
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Ryota Kimura
- Division of Organogenesis and Regeneration, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan
| | - Atsushi Suzuki
- Division of Organogenesis and Regeneration, Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
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24
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Maity S, Price BD, Wilson CB, Mukherjee A, Starck M, Parker D, Wilson MZ, Lovett JE, Han S, Sherwin MS. Triggered Functional Dynamics of AsLOV2 by Time-Resolved Electron Paramagnetic Resonance at High Magnetic Fields. Angew Chem Int Ed Engl 2023; 62:e202212832. [PMID: 36638360 DOI: 10.1002/anie.202212832] [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: 09/26/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 01/15/2023]
Abstract
We present time-resolved Gd-Gd electron paramagnetic resonance (TiGGER) at 240 GHz for tracking inter-residue distances during a protein's mechanical cycle in the solution state. TiGGER makes use of Gd-sTPATCN spin labels, whose favorable qualities include a spin-7/2 EPR-active center, short linker, narrow intrinsic linewidth, and virtually no anisotropy at high fields (8.6 T) when compared to nitroxide spin labels. Using TiGGER, we determined that upon light activation, the C-terminus and N-terminus of AsLOV2 separate in less than 1 s and relax back to equilibrium with a time constant of approximately 60 s. TiGGER revealed that the light-activated long-range mechanical motion is slowed in the Q513A variant of AsLOV2 and is correlated to the similarly slowed relaxation of the optically excited chromophore as described in recent literature. TiGGER has the potential to valuably complement existing methods for the study of triggered functional dynamics in proteins.
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Affiliation(s)
- Shiny Maity
- Dept. of Chemistry and Biochemistry, Univ. of California, Santa Barbara, CA 93106, USA
| | - Brad D Price
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA
| | - C Blake Wilson
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA.,Laboratory of Chemical Physics, Nat. Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD 20892-0520, USA
| | - Arnab Mukherjee
- Dept. of Chemical Engineering, Univ. of California, Santa Barbara, CA 93106, USA
| | | | - David Parker
- Dept. of Chemistry, Univ. of Durham, Durham, DH1 3LE, UK
| | - Maxwell Z Wilson
- Dept. of Molecular, Cellular, and Developmental Biology, Univ. of California, Santa Barbara, CA 93106, USA
| | - Janet E Lovett
- School of Physics and Astronomy and the Biomedical Sciences Research Complex, Univ. of St. Andrews, St. Andrews, KY16 9SS, UK
| | - Songi Han
- Dept. of Chemistry and Biochemistry, Univ. of California, Santa Barbara, CA 93106, USA
| | - Mark S Sherwin
- Dept. of Physics, Univ. of California, Santa Barbara, CA 93106, USA
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25
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Kim YH, Kim N, Okafor I, Choi S, Min S, Lee J, Bae SM, Choi K, Choi J, Harihar V, Kim Y, Kim JS, Kleinstiver BP, Lee JK, Ha T, Kim HH. Sniper2L is a high-fidelity Cas9 variant with high activity. Nat Chem Biol 2023:10.1038/s41589-023-01279-5. [PMID: 36894722 PMCID: PMC10374439 DOI: 10.1038/s41589-023-01279-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 02/02/2023] [Indexed: 03/11/2023]
Abstract
Although several high-fidelity SpCas9 variants have been reported, it has been observed that this increased specificity is associated with reduced on-target activity, limiting the applications of the high-fidelity variants when efficient genome editing is required. Here, we developed an improved version of Sniper-Cas9, Sniper2L, which represents an exception to this trade-off trend as it showed higher specificity with retained high activity. We evaluated Sniper2L activities at a large number of target sequences and developed DeepSniper, a deep learning model that can predict the activity of Sniper2L. We also confirmed that Sniper2L can induce highly efficient and specific editing at a large number of target sequences when it is delivered as a ribonucleoprotein complex. Mechanically, the high specificity of Sniper2L originates from its superior ability to avoid unwinding a target DNA containing even a single mismatch. We envision that Sniper2L will be useful when efficient and specific genome editing is required.
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Affiliation(s)
- Young-Hoon Kim
- Toolgen, Seoul, Republic of Korea.,Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea.,Graduate Program of Biomedical Engineering, Yonsei University College of Medicine, Seoul, Republic of Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, Republic of Korea
| | - Nahye Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea.,Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ikenna Okafor
- Department of Biology, Johns Hopkins University, Baltimore, MD, USA
| | - Sungchul Choi
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea
| | | | | | | | | | - Janice Choi
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | - Vinayak Harihar
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA
| | | | - Jin-Soo Kim
- Department of Biochemistry and NUS Synthetic Biology for Clinical & Technological Innovation (SynCTI), National University of Singapore, Singapore, Singapore
| | - Benjamin P Kleinstiver
- Center for Genomic Medicine, Massachusetts General Hospital, Boston, MA, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.,Department of Pathology, Harvard Medical School, Boston, MA, USA
| | | | - Taekjip Ha
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, USA. .,Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD, USA. .,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA. .,Howard Hughes Medical Institute, Baltimore, MD, USA.
| | - Hyongbum Henry Kim
- Department of Pharmacology, Yonsei University College of Medicine, Seoul, Republic of Korea. .,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, Republic of Korea. .,Graduate School of Medical Science, Brain Korea 21 Project, Yonsei University College of Medicine, Seoul, Republic of Korea. .,Center for Nanomedicine, Institute for Basic Science, Seoul, Republic of Korea. .,Yonsei-Institute for Basic Science Institute, Yonsei University, Seoul, Republic of Korea. .,Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Republic of Korea. .,Institute for Immunology and Immunological Diseases, Yonsei University College of Medicine, Seoul, Republic of Korea.
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26
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Nierzwicki Ł, Ahsan M, Palermo G. The Electronic Structure of Genome Editors from the First Principles. ELECTRONIC STRUCTURE (BRISTOL, ENGLAND) 2023; 5:014003. [PMID: 36926635 PMCID: PMC10016068 DOI: 10.1088/2516-1075/acb410] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Genome editing based on the CRISPR-Cas9 system has paved new avenues for medicine, pharmaceutics, biotechnology, and beyond. This article reports the role of first-principles (ab-initio) molecular dynamics (MD) in the CRISPR-Cas9 revolution, achieving a profound understanding of the enzymatic function and offering valuable insights for enzyme engineering. We introduce the methodologies and explain the use of ab-initio MD simulations to characterize the two-metal dependent mechanism of DNA cleavage in the RuvC domain of the Cas9 enzyme, and how a second catalytic domain, HNH, cleaves the target DNA with the aid of a single metal ion. A detailed description of how ab-initio MD is combined with free-energy methods - i.e., thermodynamic integration and metadynamics - to break and form chemical bonds is given, explaining the use of these methods to determine the chemical landscape and establish the catalytic mechanism in CRISPR-Cas9. The critical role of classical methods is also discussed, explaining theory and application of constant pH MD simulations, used to accurately predict the catalytic residues' protonation states. Overall, first-principles methods are shown to unravel the electronic structure of the Cas9 enzyme, providing valuable insights that can serve for the design of genome editing tools with improved catalytic efficiency or controllable activity.
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Affiliation(s)
- Łukasz Nierzwicki
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
| | - Mohd Ahsan
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
- Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA 52512, United States
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27
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Li T, Yang Y, Qi H, Cui W, Zhang L, Fu X, He X, Liu M, Li PF, Yu T. CRISPR/Cas9 therapeutics: progress and prospects. Signal Transduct Target Ther 2023; 8:36. [PMID: 36646687 PMCID: PMC9841506 DOI: 10.1038/s41392-023-01309-7] [Citation(s) in RCA: 117] [Impact Index Per Article: 117.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 12/06/2022] [Accepted: 12/27/2022] [Indexed: 01/18/2023] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene-editing technology is the ideal tool of the future for treating diseases by permanently correcting deleterious base mutations or disrupting disease-causing genes with great precision and efficiency. A variety of efficient Cas9 variants and derivatives have been developed to cope with the complex genomic changes that occur during diseases. However, strategies to effectively deliver the CRISPR system to diseased cells in vivo are currently lacking, and nonviral vectors with target recognition functions may be the focus of future research. Pathological and physiological changes resulting from disease onset are expected to serve as identifying factors for targeted delivery or targets for gene editing. Diseases are both varied and complex, and the choice of appropriate gene-editing methods and delivery vectors for different diseases is important. Meanwhile, there are still many potential challenges identified when targeting delivery of CRISPR/Cas9 technology for disease treatment. This paper reviews the current developments in three aspects, namely, gene-editing type, delivery vector, and disease characteristics. Additionally, this paper summarizes successful examples of clinical trials and finally describes possible problems associated with current CRISPR applications.
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Affiliation(s)
- Tianxiang Li
- grid.412521.10000 0004 1769 1119Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, No. 38 Dengzhou Road, 266021 Qingdao, People’s Republic of China
| | - Yanyan Yang
- grid.410645.20000 0001 0455 0905Department of Immunology, School of Basic Medicine, Qingdao University, 266021 Qingdao, People’s Republic of China
| | - Hongzhao Qi
- grid.412521.10000 0004 1769 1119Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, No. 38 Dengzhou Road, 266021 Qingdao, People’s Republic of China
| | - Weigang Cui
- grid.452710.5Department of Cardiology, People’s Hospital of Rizhao, No. 126 Taian Road, 276827 Rizhao, People’s Republic of China
| | - Lin Zhang
- Department of Microbiology, Linyi Center for Disease Control and Prevention, 276000 Linyi, People’s Republic of China
| | - Xiuxiu Fu
- grid.412521.10000 0004 1769 1119Department of Cardiac Ultrasound, The Affiliated Hospital of Qingdao University, 266000 Qingdao, People’s Republic of China
| | - Xiangqin He
- grid.412521.10000 0004 1769 1119Department of Cardiac Ultrasound, The Affiliated Hospital of Qingdao University, 266000 Qingdao, People’s Republic of China
| | - Meixin Liu
- grid.412521.10000 0004 1769 1119Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, No. 38 Dengzhou Road, 266021 Qingdao, People’s Republic of China
| | - Pei-feng Li
- grid.412521.10000 0004 1769 1119Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, No. 38 Dengzhou Road, 266021 Qingdao, People’s Republic of China
| | - Tao Yu
- Institute for Translational Medicine, The Affiliated Hospital of Qingdao University, No. 38 Dengzhou Road, 266021, Qingdao, People's Republic of China. .,Department of Cardiac Ultrasound, The Affiliated Hospital of Qingdao University, 266000, Qingdao, People's Republic of China.
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28
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Wang J, Arantes PR, Ahsan M, Sinha S, Kyro GW, Maschietto F, Allen B, Skeens E, Lisi GP, Batista VS, Palermo G. Twisting and swiveling domain motions in Cas9 to recognize target DNA duplexes, make double-strand breaks, and release cleaved duplexes. Front Mol Biosci 2023; 9:1072733. [PMID: 36699705 PMCID: PMC9868570 DOI: 10.3389/fmolb.2022.1072733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/12/2022] [Indexed: 01/11/2023] Open
Abstract
The CRISPR-associated protein 9 (Cas9) has been engineered as a precise gene editing tool to make double-strand breaks. CRISPR-associated protein 9 binds the folded guide RNA (gRNA) that serves as a binding scaffold to guide it to the target DNA duplex via a RecA-like strand-displacement mechanism but without ATP binding or hydrolysis. The target search begins with the protospacer adjacent motif or PAM-interacting domain, recognizing it at the major groove of the duplex and melting its downstream duplex where an RNA-DNA heteroduplex is formed at nanomolar affinity. The rate-limiting step is the formation of an R-loop structure where the HNH domain inserts between the target heteroduplex and the displaced non-target DNA strand. Once the R-loop structure is formed, the non-target strand is rapidly cleaved by RuvC and ejected from the active site. This event is immediately followed by cleavage of the target DNA strand by the HNH domain and product release. Within CRISPR-associated protein 9, the HNH domain is inserted into the RuvC domain near the RuvC active site via two linker loops that provide allosteric communication between the two active sites. Due to the high flexibility of these loops and active sites, biophysical techniques have been instrumental in characterizing the dynamics and mechanism of the CRISPR-associated protein 9 nucleases, aiding structural studies in the visualization of the complete active sites and relevant linker structures. Here, we review biochemical, structural, and biophysical studies on the underlying mechanism with emphasis on how CRISPR-associated protein 9 selects the target DNA duplex and rejects non-target sequences.
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Affiliation(s)
- Jimin Wang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, United States
| | - Pablo R. Arantes
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Mohd Ahsan
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Souvik Sinha
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
| | - Gregory W. Kyro
- Department of Chemistry, Yale University, New Haven, CT, United States
| | | | - Brandon Allen
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - Erin Skeens
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - George P. Lisi
- Department of Molecular and Cell Biology and Biochemistry, Brown University, Providence, RI, United States
| | - Victor S. Batista
- Department of Chemistry, Yale University, New Haven, CT, United States
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California, Riverside, Riverside, CA, United States
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29
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Okafor I, Ha T. Single Molecule FRET Analysis of CRISPR Cas9 Single Guide RNA Folding Dynamics. J Phys Chem B 2022; 127:45-51. [PMID: 36563314 PMCID: PMC9841515 DOI: 10.1021/acs.jpcb.2c05428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
CRISPR Cas9 is an RNA guided endonuclease that is part of a bacterial adaptive immune system. Single guide RNA (sgRNA) can be designed to target genomic DNA, making Cas9 a programmable DNA binding/cutting enzyme and allowing applications such as epigenome editing, controlling transcription, and targeted DNA insertion. Some of the main hurdles against an even wider adoption are off-target effects and variability in Cas9 editing outcomes. Most studies that aim to understand the mechanisms that underlie these two areas have focused on Cas9 DNA binding, DNA unwinding, and target cleavage. The assembly of Cas9 RNA ribonucleoprotein complex (RNP) precedes all these steps and includes sgRNA folding and Cas9 binding to sgRNA. We know from the crystal structure of the Cas9 RNP what the final sgRNA conformation is. However, the assembly dynamics has not been studied in detail and a better understanding of RNP assembly could lead to better-designed sgRNAs and better editing outcomes. To study this process, we developed a single molecule FRET assay to monitor the conformation of the sgRNA and the binding of Cas9 to sgRNA. We labeled the sgRNA with a donor fluorophore and an acceptor fluorophore such that when the sgRNA folds, there are changes in FRET efficiency. We measured sgRNA folding dynamics under different ion conditions, under various methods of folding (refolding vs vectorial), and with or without Cas9. sgRNA that closely mimics the sgRNA construct used for high resolution structural analysis of the Cas9-gRNA complex showed two main FRET states without Cas9, and Cas9 addition shifted the distribution toward the higher FRET state attributed to the properly assembled complex. Even in the absence of Cas9, folding the sgRNA vectorially using a superhelicase-dependent release of the sgRNA in the direction of transcription resulted in almost exclusively high FRET state. An addition of Cas9 during vectorial folding greatly reduced a slow-folding fraction. Our studies shed light on the heterogeneous folding dynamics of sgRNA and the impact of co-transcriptional folding and Cas9 binding in sgRNA folding. Further studies of sequence dependence may inform rational design of sgRNAs for optimal function.
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Affiliation(s)
- Ikenna
C. Okafor
- Department
of Biology, Johns Hopkins University, Baltimore, Maryland 21218, United States
| | - Taekjip Ha
- Department
of Biophysics, Johns Hopkins University, Baltimore, Maryland 21218, United States,Department
of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, United States,Department
of Biomedical Engineering, Johns Hopkins
University, Baltimore, Maryland 21218, United States,Howard
Hughes Medical Institute, Baltimore, Maryland 21205, United States,
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30
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Wang Y, Cottle WT, Wang H, Gavrilov M, Zou RS, Pham MT, Yegnasubramanian S, Bailey S, Ha T. Achieving single nucleotide sensitivity in direct hybridization genome imaging. Nat Commun 2022; 13:7776. [PMID: 36522352 PMCID: PMC9755149 DOI: 10.1038/s41467-022-35476-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
Direct visualization of point mutations in situ can be informative for studying genetic diseases and nuclear biology. We describe a direct hybridization genome imaging method with single-nucleotide sensitivity, single guide genome oligopaint via local denaturation fluorescence in situ hybridization (sgGOLDFISH), which leverages the high cleavage specificity of eSpCas9(1.1) variant combined with a rationally designed guide RNA to load a superhelicase and reveal probe binding sites through local denaturation. The guide RNA carries an intentionally introduced mismatch so that while wild-type target DNA sequence can be efficiently cleaved, a mutant sequence with an additional mismatch (e.g., caused by a point mutation) cannot be cleaved. Because sgGOLDFISH relies on genomic DNA being cleaved by Cas9 to reveal probe binding sites, the probes will only label the wild-type sequence but not the mutant sequence. Therefore, sgGOLDFISH has the sensitivity to differentiate the wild-type and mutant sequences differing by only a single base pair. Using sgGOLDFISH, we identify base-editor-modified and unmodified progeroid fibroblasts from a heterogeneous population, validate the identification through progerin immunofluorescence, and demonstrate accurate sub-nuclear localization of point mutations.
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Affiliation(s)
- Yanbo Wang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - W Taylor Cottle
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Haobo Wang
- Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Momcilo Gavrilov
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Roger S Zou
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Minh-Tam Pham
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Srinivasan Yegnasubramanian
- Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Cellular and Molecular Medicine Graduate Program, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Scott Bailey
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA.
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, USA.
- Department of Biophysics, Johns Hopkins University, Baltimore, MD, 21218, USA.
- Howard Hughes Medical Institute, Baltimore, MD, 21205, USA.
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31
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A quantitative model for the dynamics of target recognition and off-target rejection by the CRISPR-Cas Cascade complex. Nat Commun 2022; 13:7460. [PMID: 36460652 PMCID: PMC9718816 DOI: 10.1038/s41467-022-35116-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 11/18/2022] [Indexed: 12/05/2022] Open
Abstract
CRISPR-Cas effector complexes recognise nucleic acid targets by base pairing with their crRNA which enables easy re-programming of the target specificity in rapidly emerging genome engineering applications. However, undesired recognition of off-targets, that are only partially complementary to the crRNA, occurs frequently and represents a severe limitation of the technique. Off-targeting lacks comprehensive quantitative understanding and prediction. Here, we present a detailed analysis of the target recognition dynamics by the Cascade surveillance complex on a set of mismatched DNA targets using single-molecule supercoiling experiments. We demonstrate that the observed dynamics can be quantitatively modelled as a random walk over the length of the crRNA-DNA hybrid using a minimal set of parameters. The model accurately describes the recognition of targets with single and double mutations providing an important basis for quantitative off-target predictions. Importantly the model intrinsically accounts for observed bias regarding the position and the proximity between mutations and reveals that the seed length for the initiation of target recognition is controlled by DNA supercoiling rather than the Cascade structure.
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32
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Bravo JP, Hibshman GN, Taylor DW. Constructing next-generation CRISPR-Cas tools from structural blueprints. Curr Opin Biotechnol 2022; 78:102839. [PMID: 36371895 DOI: 10.1016/j.copbio.2022.102839] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 09/18/2022] [Accepted: 10/10/2022] [Indexed: 11/12/2022]
Abstract
Clustered regularly interspaced short palindromic repeats - CRISPR-associated protein (CRISPR-Cas) systems are a critical component of the bacterial adaptive immune response. Since the discovery that they can be reengineered as programmable RNA-guided nucleases, there has been significant interest in using these systems to perform diverse and precise genetic manipulations. Here, we outline recent advances in the mechanistic understanding of CRISPR-Cas9, how these findings have been leveraged in the rational redesign of Cas9 variants with altered activities, and how these novel tools can be exploited for biotechnology and therapeutics. We also discuss the potential of the ubiquitous, yet often-overlooked, multisubunit CRISPR effector complexes for large-scale genomic deletions. Furthermore, we highlight how future structural studies will bolster these technologies.
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Affiliation(s)
- Jack Pk Bravo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA.
| | - Grace N Hibshman
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX, USA
| | - David W Taylor
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX, USA; Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX, USA; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, TX, USA; Livestrong Cancer Institutes, Dell Medical School, Austin, TX, USA
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Saha A, Arantes PR, Palermo G. Dynamics and mechanisms of CRISPR-Cas9 through the lens of computational methods. Curr Opin Struct Biol 2022; 75:102400. [PMID: 35689914 PMCID: PMC9398989 DOI: 10.1016/j.sbi.2022.102400] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 04/25/2022] [Accepted: 05/07/2022] [Indexed: 12/24/2022]
Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR) genome-editing revolution established the beginning of a new era in life sciences. Here, we review the role of state-of-the-art computations in the CRISPR-Cas9 revolution, from the early refinement of cryo-EM data to enhanced simulations of large-scale conformational transitions. Molecular simulations reported a mechanism for RNA binding and the formation of a catalytically competent Cas9 enzyme, in agreement with subsequent structural studies. Inspired by single-molecule experiments, molecular dynamics offered a rationale for the onset of off-target effects, while graph theory unveiled the allosteric regulation. Finally, the use of a mixed quantum-classical approach established the catalytic mechanism of DNA cleavage. Overall, molecular simulations have been instrumental in understanding the dynamics and mechanism of CRISPR-Cas9, contributing to understanding function, catalysis, allostery, and specificity.
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Affiliation(s)
- Aakash Saha
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States. https://twitter.com/@aakashsahha
| | - Pablo R Arantes
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States. https://twitter.com/@pablitoarantes
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States; Department of Chemistry, University of California Riverside, 900 University Avenue, Riverside, CA, 52512, United States.
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Bachman JL, Wight CD, Bardo AM, Johnson AM, Pavlich CI, Boley AJ, Wagner HR, Swaminathan J, Iverson BL, Marcotte EM, Anslyn EV. Evaluating the Effect of Dye-Dye Interactions of Xanthene-Based Fluorophores in the Fluorosequencing of Peptides. Bioconjug Chem 2022; 33:1156-1165. [PMID: 35622964 DOI: 10.1021/acs.bioconjchem.2c00103] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A peptide sequencing scheme utilizing fluorescence microscopy and Edman degradation to determine the amino acid position in fluorophore-labeled peptides was recently reported, referred to as fluorosequencing. It was observed that multiple fluorophores covalently linked to a peptide scaffold resulted in a decrease in the anticipated fluorescence output and worsened the single-molecule fluorescence analysis. In this study, we report an improvement in the photophysical properties of fluorophore-labeled peptides by incorporating long and flexible (PEG)10 linkers at the peptide attachment points. Long linkers to the fluorophores were installed using copper-catalyzed azide-alkyne cycloaddition conditions. The photophysical properties of these peptides were analyzed in solution and immobilized on a microscope slide at the single-molecule level under peptide fluorosequencing conditions. Solution-phase fluorescence analysis showed improvements in both quantum yield and fluorescence lifetime with the long linkers. While on the solid support, photometry measurements showed significant increases in fluorescence brightness and 20 to 60% improvements in the ability to determine the amino acid position with fluorosequencing. This spatial distancing strategy demonstrates improvements in the peptide sequencing platform and provides a general approach for improving the photophysical properties in fluorophore-labeled macromolecules.
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Affiliation(s)
- James L Bachman
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Christopher D Wight
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Angela M Bardo
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Amber M Johnson
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Cyprian I Pavlich
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Alexander J Boley
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Holden R Wagner
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Jagannath Swaminathan
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Brent L Iverson
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Edward M Marcotte
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas 78712, United States
| | - Eric V Anslyn
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78712, United States
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35
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Li Y, Liu Y, Singh J, Tangprasertchai NS, Trivedi R, Fang Y, Qin PZ. Site-Specific Labeling Reveals Cas9 Induces Partial Unwinding Without RNA/DNA Pairing in Sequences Distal to the PAM. CRISPR J 2022; 5:341-352. [PMID: 35352981 DOI: 10.1089/crispr.2021.0100] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
CRISPR-Cas9 is an RNA-guided nuclease that has been widely adapted for genome engineering. A key determinant in Cas9 target selection is DNA duplex unwinding to form an R-loop, in which the single-stranded RNA guide hybridizes with one of the DNA strands. To advance understanding on DNA unwinding by Cas9, we combined two types of spectroscopic label, 2-aminopurine and nitroxide spin-label, to investigate unwinding at a specific DNA base pair induced by Streptococcus pyogenes Cas9. Data obtained with RNA guide lengths varying from 13 to 20 nucleotide revealed that the DNA segment distal to the protospacer adjacent motif can adopt a "partial unwinding" state, in which a mixture of DNA-paired and DNA-unwound populations exist in equilibrium. Significant unwinding can occur at positions not supported by RNA/DNA pairing, and the degree of unwinding depends on RNA guide length and modulates DNA cleavage activity. The results shed light on Cas9 target selection and may inform developments of genome-engineering strategies.
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Affiliation(s)
- Yue Li
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Yukang Liu
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Jaideep Singh
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | | | - Ravi Trivedi
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Yun Fang
- Department of Chemistry, University of Southern California, Los Angeles, California, USA
| | - Peter Z Qin
- Department of Chemistry, University of Southern California, Los Angeles, California, USA.,Department of Biological Sciences, University of Southern California, Los Angeles, California, USA
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36
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Bravo JPK, Liu MS, Hibshman GN, Dangerfield TL, Jung K, McCool RS, Johnson KA, Taylor DW. Structural basis for mismatch surveillance by CRISPR–Cas9. Nature 2022. [DOI: 10.1038/s41586-022-04470-1 (2022)] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AbstractCRISPR–Cas9 as a programmable genome editing tool is hindered by off-target DNA cleavage1–4, and the underlying mechanisms by which Cas9 recognizes mismatches are poorly understood5–7. Although Cas9 variants with greater discrimination against mismatches have been designed8–10, these suffer from substantially reduced rates of on-target DNA cleavage5,11. Here we used kinetics-guided cryo-electron microscopy to determine the structure of Cas9 at different stages of mismatch cleavage. We observed a distinct, linear conformation of the guide RNA–DNA duplex formed in the presence of mismatches, which prevents Cas9 activation. Although the canonical kinked guide RNA–DNA duplex conformation facilitates DNA cleavage, we observe that substrates that contain mismatches distal to the protospacer adjacent motif are stabilized by reorganization of a loop in the RuvC domain. Mutagenesis of mismatch-stabilizing residues reduces off-target DNA cleavage but maintains rapid on-target DNA cleavage. By targeting regions that are exclusively involved in mismatch tolerance, we provide a proof of concept for the design of next-generation high-fidelity Cas9 variants.
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37
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Wan Y, Zong C, Li X, Wang A, Li Y, Yang T, Bao Q, Dubow M, Yang M, Rodrigo LA, Mao C. New Insights for Biosensing: Lessons from Microbial Defense Systems. Chem Rev 2022; 122:8126-8180. [PMID: 35234463 DOI: 10.1021/acs.chemrev.1c01063] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Microorganisms have gained defense systems during the lengthy process of evolution over millions of years. Such defense systems can protect them from being attacked by invading species (e.g., CRISPR-Cas for establishing adaptive immune systems and nanopore-forming toxins as virulence factors) or enable them to adapt to different conditions (e.g., gas vesicles for achieving buoyancy control). These microorganism defense systems (MDS) have inspired the development of biosensors that have received much attention in a wide range of fields including life science research, food safety, and medical diagnosis. This Review comprehensively analyzes biosensing platforms originating from MDS for sensing and imaging biological analytes. We first describe a basic overview of MDS and MDS-inspired biosensing platforms (e.g., CRISPR-Cas systems, nanopore-forming proteins, and gas vesicles), followed by a critical discussion of their functions and properties. We then discuss several transduction mechanisms (optical, acoustic, magnetic, and electrical) involved in MDS-inspired biosensing. We further detail the applications of the MDS-inspired biosensors to detect a variety of analytes (nucleic acids, peptides, proteins, pathogens, cells, small molecules, and metal ions). In the end, we propose the key challenges and future perspectives in seeking new and improved MDS tools that can potentially lead to breakthrough discoveries in developing a new generation of biosensors with a combination of low cost; high sensitivity, accuracy, and precision; and fast detection. Overall, this Review gives a historical review of MDS, elucidates the principles of emulating MDS to develop biosensors, and analyzes the recent advancements, current challenges, and future trends in this field. It provides a unique critical analysis of emulating MDS to develop robust biosensors and discusses the design of such biosensors using elements found in MDS, showing that emulating MDS is a promising approach to conceptually advancing the design of biosensors.
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Affiliation(s)
- Yi Wan
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Pharmaceutical Sciences, Marine College, Hainan University, Haikou 570228, P. R. China
| | - Chengli Zong
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Pharmaceutical Sciences, Marine College, Hainan University, Haikou 570228, P. R. China
| | - Xiangpeng Li
- Department of Bioengineering and Therapeutic Sciences, Schools of Medicine and Pharmacy, University of California, San Francisco, 1700 Fourth Street, Byers Hall 303C, San Francisco, California 94158, United States
| | - Aimin Wang
- State Key Laboratory of Marine Resource Utilization in the South China Sea, School of Pharmaceutical Sciences, Marine College, Hainan University, Haikou 570228, P. R. China
| | - Yan Li
- College of Animal Science, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Tao Yang
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Qing Bao
- School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Michael Dubow
- Institute for Integrative Biology of the Cell (I2BC), UMR 9198 CNRS, CEA, Université Paris-Saclay, Campus C.N.R.S, Bâtiment 12, Avenue de la Terrasse, 91190 Gif-sur-Yvette, France
| | - Mingying Yang
- College of Animal Science, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
| | - Ledesma-Amaro Rodrigo
- Imperial College Centre for Synthetic Biology, Department of Bioengineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Chuanbin Mao
- Department of Chemistry & Biochemistry, Stephenson Life Science Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States.,School of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310058, P. R. China
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38
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Bravo JPK, Liu MS, Hibshman GN, Dangerfield TL, Jung K, McCool RS, Johnson KA, Taylor DW. Structural basis for mismatch surveillance by CRISPR-Cas9. Nature 2022; 603:343-347. [PMID: 35236982 PMCID: PMC8907077 DOI: 10.1038/s41586-022-04470-1] [Citation(s) in RCA: 113] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 01/25/2022] [Indexed: 11/09/2022]
Abstract
CRISPR-Cas9 as a programmable genome editing tool is hindered by off-target DNA cleavage1-4, and the underlying mechanisms by which Cas9 recognizes mismatches are poorly understood5-7. Although Cas9 variants with greater discrimination against mismatches have been designed8-10, these suffer from substantially reduced rates of on-target DNA cleavage5,11. Here we used kinetics-guided cryo-electron microscopy to determine the structure of Cas9 at different stages of mismatch cleavage. We observed a distinct, linear conformation of the guide RNA-DNA duplex formed in the presence of mismatches, which prevents Cas9 activation. Although the canonical kinked guide RNA-DNA duplex conformation facilitates DNA cleavage, we observe that substrates that contain mismatches distal to the protospacer adjacent motif are stabilized by reorganization of a loop in the RuvC domain. Mutagenesis of mismatch-stabilizing residues reduces off-target DNA cleavage but maintains rapid on-target DNA cleavage. By targeting regions that are exclusively involved in mismatch tolerance, we provide a proof of concept for the design of next-generation high-fidelity Cas9 variants.
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Affiliation(s)
- Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Mu-Sen Liu
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Grace N Hibshman
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Tyler L Dangerfield
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Kyungseok Jung
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Ryan S McCool
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA
| | - Kenneth A Johnson
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA.
| | - David W Taylor
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA.
- Livestrong Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX, USA.
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39
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Belato HB, D'Ordine AM, Nierzwicki L, Arantes PR, Jogl G, Palermo G, Lisi GP. Structural and dynamic insights into the HNH nuclease of divergent Cas9 species. J Struct Biol 2022; 214:107814. [PMID: 34871741 PMCID: PMC8917064 DOI: 10.1016/j.jsb.2021.107814] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Revised: 10/15/2021] [Accepted: 11/29/2021] [Indexed: 12/19/2022]
Abstract
CRISPR-Cas9 is a widely used biochemical tool with applications in molecular biology and precision medicine. The RNA-guided Cas9 protein uses its HNH endonuclease domain to cleave the DNA strand complementary to its endogenous guide RNA. In this study, novel constructs of HNH from two divergent organisms, G. stearothermophilus (GeoHNH) and S. pyogenes (SpHNH) were engineered from their respective full-length Cas9 proteins. Despite low sequence similarity, the X-ray crystal structures of these constructs reveal that the core of HNH surrounding the active site is conserved. Structure prediction of the full-length GeoCas9 protein using Phyre2 and AlphaFold2 also showed that the crystallographic construct of GeoHNH represents the structure of the domain within the full-length GeoCas9 protein. However, significant differences are observed in the solution dynamics of structurally conserved regions of GeoHNH and SpHNH, the latter of which was shown to use such molecular motions to propagate the DNA cleavage signal. Indeed, molecular simulations show that the intradomain signaling pathways, which drive SpHNH function, are non-specific and poorly formed in GeoHNH. Taken together, these outcomes suggest mechanistic differences between mesophilic and thermophilic Cas9 species.
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Affiliation(s)
- Helen B Belato
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI, USA
| | - Alexandra M D'Ordine
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI, USA
| | - Lukasz Nierzwicki
- Department of Bioengineering, University of California Riverside, Riverside, CA, USA
| | - Pablo R Arantes
- Department of Bioengineering, University of California Riverside, Riverside, CA, USA
| | - Gerwald Jogl
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI, USA
| | - Giulia Palermo
- Department of Bioengineering, University of California Riverside, Riverside, CA, USA; Department of Chemistry, University of California Riverside, Riverside, CA, USA.
| | - George P Lisi
- Department of Molecular Biology, Cell Biology & Biochemistry, Brown University, Providence, RI, USA.
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40
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Newton MD, Taylor BJ, Cuomo ME, Rueda DS. CRISPR/Cas9 On- and Off-Target Activity Using Correlative Force and Fluorescence Single-Molecule Microscopy. Methods Mol Biol 2022; 2478:349-378. [PMID: 36063327 DOI: 10.1007/978-1-0716-2229-2_13] [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] [Indexed: 06/15/2023]
Abstract
The discovery of CRISPR/Cas9 as an easily programmable endonuclease heralds a new era of genetic manipulation. With this comes the prospect of novel gene therapy approaches, and the potential to cure previously untreatable genetic diseases. However, reports of spurious off-target editing by CRISPR/Cas9 pose a significant hurdle to realizing this potential. A deeper understanding of the factors that affect Cas9 specificity is vital for development of safe and efficient therapeutics. Here, we describe methods for the use of optical tweezers combined with confocal fluorescence microscopy and microfluidics for the analysis of on- and off-target activity of Cas9 activity.
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Affiliation(s)
- Matthew D Newton
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK
- Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London, UK
| | | | | | - David S Rueda
- Department of Infectious Disease, Faculty of Medicine, Imperial College London, London, UK.
- Single Molecule Imaging Group, MRC-London Institute of Medical Sciences, London, UK.
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41
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Nierzwicki L, East KW, Morzan UN, Arantes PR, Batista VS, Lisi GP, Palermo G. Enhanced specificity mutations perturb allosteric signaling in CRISPR-Cas9. eLife 2021; 10:e73601. [PMID: 34908530 PMCID: PMC8741213 DOI: 10.7554/elife.73601] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 12/14/2021] [Indexed: 11/13/2022] Open
Abstract
CRISPR-Cas9 (clustered regularly interspaced short palindromic repeat and associated Cas9 protein) is a molecular tool with transformative genome editing capabilities. At the molecular level, an intricate allosteric signaling is critical for DNA cleavage, but its role in the specificity enhancement of the Cas9 endonuclease is poorly understood. Here, multi-microsecond molecular dynamics is combined with solution NMR and graph theory-derived models to probe the allosteric role of key specificity-enhancing mutations. We show that mutations responsible for increasing the specificity of Cas9 alter the allosteric structure of the catalytic HNH domain, impacting the signal transmission from the DNA recognition region to the catalytic sites for cleavage. Specifically, the K855A mutation strongly disrupts the allosteric connectivity of the HNH domain, exerting the highest perturbation on the signaling transfer, while K810A and K848A result in more moderate effects on the allosteric communication. This differential perturbation of the allosteric signal correlates to the order of specificity enhancement (K855A > K848A ~ K810A) observed in biochemical studies, with the mutation achieving the highest specificity most strongly perturbing the signaling transfer. These findings suggest that alterations of the allosteric communication from DNA recognition to cleavage are critical to increasing the specificity of Cas9 and that allosteric hotspots can be targeted through mutational studies for improving the system's function.
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Affiliation(s)
- Lukasz Nierzwicki
- Department of Bioengineering and Department of Chemistry, University of California, RiversideRiversideUnited States
| | - Kyle W East
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidenceUnited States
| | - Uriel N Morzan
- International Centre for Theoretical PhysicsTriesteItaly
| | - Pablo R Arantes
- Department of Bioengineering and Department of Chemistry, University of California, RiversideRiversideUnited States
| | | | - George P Lisi
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown UniversityProvidenceUnited States
| | - Giulia Palermo
- Department of Bioengineering and Department of Chemistry, University of California, RiversideRiversideUnited States
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42
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Aldag P, Welzel F, Jakob L, Schmidbauer A, Rutkauskas M, Fettes F, Grohmann D, Seidel R. Probing the stability of the SpCas9-DNA complex after cleavage. Nucleic Acids Res 2021; 49:12411-12421. [PMID: 34792162 PMCID: PMC8643700 DOI: 10.1093/nar/gkab1072] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 10/14/2021] [Accepted: 10/20/2021] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas9 is a ribonucleoprotein complex that sequence-specifically binds and cleaves double-stranded DNA. Wildtype Cas9 and its nickase and cleavage-incompetent mutants have been used in various biological techniques due to their versatility and programmable specificity. Cas9 has been shown to bind very stably to DNA even after cleavage of the individual DNA strands, inhibiting further turnovers and considerably slowing down in-vivo repair processes. This poses an obstacle in genome editing applications. Here, we employed single-molecule magnetic tweezers to investigate the binding stability of different Streptococcus pyogenes Cas9 variants after cleavage by challenging them with supercoiling. We find that different release mechanisms occur depending on which DNA strand is cleaved. After initial target strand cleavage, supercoils are only removed after the collapse of the R-loop. We identified several states with different stabilities of the R-loop. Most importantly, we find that the post-cleavage state of Cas9 exhibits a higher stability than the pre-cleavage state. After non-target strand cleavage, supercoils are immediately but slowly released by swiveling of the non-target strand around Cas9 bound to the target strand. Consequently, Cas9 and its non-target strand nicking mutant stay stably bound to the DNA for many hours even at elevated torsional stress.
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Affiliation(s)
- Pierre Aldag
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Fabian Welzel
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Leonhard Jakob
- Institute of Microbiology & Archaea Centre, Single-Molecule Biochemistry Lab, University of Regensburg, Regensburg 93053, Germany
| | - Andreas Schmidbauer
- Institute of Microbiology & Archaea Centre, Single-Molecule Biochemistry Lab, University of Regensburg, Regensburg 93053, Germany
| | - Marius Rutkauskas
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Fergus Fettes
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Dina Grohmann
- Institute of Microbiology & Archaea Centre, Single-Molecule Biochemistry Lab, University of Regensburg, Regensburg 93053, Germany
- Regensburg Center of Biochemistry (RCB), University of Regensburg, 93053 Regensburg, Germany
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
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43
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Zhang Q, Chen Z, Wang F, Zhang S, Chen H, Gu X, Wen F, Jin J, Zhang X, Huang X, Shen B, Sun B. Efficient DNA interrogation of SpCas9 governed by its electrostatic interaction with DNA beyond the PAM and protospacer. Nucleic Acids Res 2021; 49:12433-12444. [PMID: 34850124 PMCID: PMC8643646 DOI: 10.1093/nar/gkab1139] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 12/26/2022] Open
Abstract
Streptococcus pyogenes Cas9 (SpCas9), a programmable RNA-guided DNA endonuclease, has been widely repurposed for biological and medical applications. Critical interactions between SpCas9 and DNA confer the high specificity of the enzyme in genome engineering. Here, we unveil that an essential SpCas9–DNA interaction located beyond the protospacer adjacent motif (PAM) is realized through electrostatic forces between four positively charged lysines among SpCas9 residues 1151–1156 and the negatively charged DNA backbone. Modulating this interaction by substituting lysines with amino acids that have distinct charges revealed a strong dependence of DNA target binding and cleavage activities of SpCas9 on the charge. Moreover, the SpCas9 mutants show markedly distinguishable DNA interaction sites beyond the PAM compared with wild-type SpCas9. Functionally, this interaction governs DNA sampling and participates in protospacer DNA unwinding during DNA interrogation. Overall, a mechanistic and functional understanding of this vital interaction explains how SpCas9 carries out efficient DNA interrogation.
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Affiliation(s)
- Qian Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ziting Chen
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Fangzhu Wang
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Gusu School, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Siqi Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hongyu Chen
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Gusu School, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Xueying Gu
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Gusu School, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Fengcai Wen
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai 200031, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiachuan Jin
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Gusu School, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Xia Zhang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China
| | - Xingxu Huang
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Gene Editing Center, ShanghaiTech University, Shanghai 201210, China
| | - Bin Shen
- State Key Laboratory of Reproductive Medicine, Center for Global Health, Gusu School, Women's Hospital of Nanjing Medical University, Nanjing Maternity and Child Health Care Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Bo Sun
- School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China.,Gene Editing Center, ShanghaiTech University, Shanghai 201210, China
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44
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Bak SY, Jung Y, Park J, Sung K, Jang HK, Bae S, Kim SK. Quantitative assessment of engineered Cas9 variants for target specificity enhancement by single-molecule reaction pathway analysis. Nucleic Acids Res 2021; 49:11312-11322. [PMID: 34554247 PMCID: PMC8565309 DOI: 10.1093/nar/gkab858] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 09/07/2021] [Accepted: 09/14/2021] [Indexed: 12/26/2022] Open
Abstract
There have been many engineered Cas9 variants that were developed to minimize unintended cleavage of off-target DNAs, but detailed mechanism for the way they regulate the target specificity through DNA:RNA heteroduplexation remains poorly understood. We used single-molecule FRET assay to follow the dynamics of DNA:RNA heteroduplexation for various engineered Cas9 variants with respect to on-target and off-target DNAs. Just like wild-type Cas9, these engineered Cas9 variants exhibit a strong correlation between their conformational structure and nuclease activity. Compared with wild-type Cas9, the fraction of the cleavage-competent state dropped more rapidly with increasing base-pair mismatch, which gives rise to their enhanced target specificity. We proposed a reaction model to quantitatively analyze the degree of off-target discrimination during the successive process of R-loop expansion. We found that the critical specificity enhancement step is activated during DNA:RNA heteroduplexation for evoCas9 and HypaCas9, while it occurs in the post-heteroduplexation stage for Cas9-HF1, eCas9, and Sniper-Cas9. This study sheds new light on the conformational dynamics behind the target specificity of Cas9, which will help strengthen its rational designing principles in the future.
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Affiliation(s)
- So Young Bak
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Youngri Jung
- Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea
| | - Jinho Park
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Keewon Sung
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyeon-Ki Jang
- Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea
| | - Sangsu Bae
- Department of Chemistry and Research Institute for Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea
| | - Seong Keun Kim
- Department of Chemistry, Seoul National University, Seoul 08826, Republic of Korea
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45
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Banerjee T, Takahashi H, Subekti DRG, Kamagata K. Engineering of the genome editing protein Cas9 to slide along DNA. Sci Rep 2021; 11:14165. [PMID: 34239016 PMCID: PMC8266852 DOI: 10.1038/s41598-021-93685-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 06/28/2021] [Indexed: 12/26/2022] Open
Abstract
The genome editing protein Cas9 faces engineering challenges in improving off-target DNA cleavage and low editing efficiency. In this study, we aimed to engineer Cas9 to be able to slide along DNA, which might facilitate genome editing and reduce off-target cleavage. We used two approaches to achieve this: reducing the sliding friction along DNA by removing the interactions of Cas9 residues with DNA and facilitating sliding by introducing the sliding-promoting tail of Nhp6A. Seven engineered mutants of Cas9 were prepared, and their performance was tested using single-molecule fluorescence microscopy. Comparison of the mutations enabled the identification of key residues of Cas9 to enhance the sliding along DNA in the presence and absence of single guide RNA (sgRNA). The attachment of the tail to Cas9 mutants enhanced sliding along DNA, particularly in the presence of sgRNA. Together, using the proposed approaches, the sliding ability of Cas9 was improved up to eightfold in the presence of sgRNA. A sliding model of Cas9 and its engineering action are discussed herein.
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Affiliation(s)
- Trishit Banerjee
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan
| | - Hiroto Takahashi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan
| | - Dwiky Rendra Graha Subekti
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan
| | - Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan.
- Department of Chemistry, Graduate School of Science, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai, 980-8577, Japan.
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46
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Fairlamb MS, Whitaker AM, Bain FE, Spies M, Freudenthal BD. Construction of a Three-Color Prism-Based TIRF Microscope to Study the Interactions and Dynamics of Macromolecules. BIOLOGY 2021; 10:biology10070571. [PMID: 34201434 PMCID: PMC8301196 DOI: 10.3390/biology10070571] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/08/2021] [Accepted: 06/15/2021] [Indexed: 02/05/2023]
Abstract
Simple Summary Prism-based single-molecule total internal reflection fluorescence (prismTIRF) microscopes are excellent tools for studying macromolecular dynamics and interactions. Here, we provide an easy-to-follow guide for the design, assembly, and operation of a three-color prismTIRF microscope using commercially available components with the hope of assisting those who aim to implement TIRF imaging techniques in their laboratory. Abstract Single-molecule total internal reflection fluorescence (TIRF) microscopy allows for the real-time visualization of macromolecular dynamics and complex assembly. Prism-based TIRF microscopes (prismTIRF) are relatively simple to operate and can be easily modulated to fit the needs of a wide variety of experimental applications. While building a prismTIRF microscope without expert assistance can pose a significant challenge, the components needed to build a prismTIRF microscope are relatively affordable and, with some guidance, the assembly can be completed by a determined novice. Here, we provide an easy-to-follow guide for the design, assembly, and operation of a three-color prismTIRF microscope which can be utilized for the study of macromolecular complexes, including the multi-component protein–DNA complexes responsible for DNA repair, replication, and transcription. Our hope is that this article can assist laboratories that aspire to implement single-molecule TIRF techniques, and consequently expand the application of this technology.
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Affiliation(s)
- Max S. Fairlamb
- Department of Biochemistry and Molecular Biology and Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (M.S.F.); (A.M.W.)
| | - Amy M. Whitaker
- Department of Biochemistry and Molecular Biology and Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (M.S.F.); (A.M.W.)
| | - Fletcher E. Bain
- Department of Biochemistry and Molecular Biology, University of Iowa Carver College of Medicine, 51 Newton Road, Iowa City, IA 52242, USA; (F.E.B.); (M.S.)
| | - Maria Spies
- Department of Biochemistry and Molecular Biology, University of Iowa Carver College of Medicine, 51 Newton Road, Iowa City, IA 52242, USA; (F.E.B.); (M.S.)
| | - Bret D. Freudenthal
- Department of Biochemistry and Molecular Biology and Department of Cancer Biology, University of Kansas Medical Center, Kansas City, KS 66160, USA; (M.S.F.); (A.M.W.)
- Correspondence:
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47
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Murugan K, Suresh SK, Seetharam AS, Severin AJ, Sashital DG. Systematic in vitro specificity profiling reveals nicking defects in natural and engineered CRISPR-Cas9 variants. Nucleic Acids Res 2021; 49:4037-4053. [PMID: 33744974 PMCID: PMC8053117 DOI: 10.1093/nar/gkab163] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 02/23/2021] [Accepted: 03/01/2021] [Indexed: 12/15/2022] Open
Abstract
Cas9 is an RNA-guided endonuclease in the bacterial CRISPR-Cas immune system and a popular tool for genome editing. The commonly used Streptococcus pyogenes Cas9 (SpCas9) is relatively non-specific and prone to off-target genome editing. Other Cas9 orthologs and engineered variants of SpCas9 have been reported to be more specific. However, previous studies have focused on specificity of double-strand break (DSB) or indel formation, potentially overlooking alternative cleavage activities of these Cas9 variants. In this study, we employed in vitro cleavage assays of target libraries coupled with high-throughput sequencing to systematically compare cleavage activities and specificities of two natural Cas9 variants (SpCas9 and Staphylococcus aureus Cas9) and three engineered SpCas9 variants (SpCas9 HF1, HypaCas9 and HiFi Cas9). We observed that all Cas9s tested could cleave target sequences with up to five mismatches. However, the rate of cleavage of both on-target and off-target sequences varied based on target sequence and Cas9 variant. In addition, SaCas9 and engineered SpCas9 variants nick targets with multiple mismatches but have a defect in generating a DSB, while SpCas9 creates DSBs at these targets. Overall, these differences in cleavage rates and DSB formation may contribute to varied specificities observed in genome editing studies.
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Affiliation(s)
- Karthik Murugan
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA
- Molecular, Cellular, and Developmental Biology Interdepartmental Program, Iowa State University, Ames, IA 50011, USA
| | - Shravanti K Suresh
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Arun S Seetharam
- Genome Informatics Facility, Office of Biotechnology, Iowa State University, Ames, IA 50011, USA
| | - Andrew J Severin
- Genome Informatics Facility, Office of Biotechnology, Iowa State University, Ames, IA 50011, USA
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics & Molecular Biology, Iowa State University, Ames, IA 50011, USA
- Molecular, Cellular, and Developmental Biology Interdepartmental Program, Iowa State University, Ames, IA 50011, USA
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48
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Wang Y, Cottle WT, Wang H, Feng XA, Mallon J, Gavrilov M, Bailey S, Ha T. Genome oligopaint via local denaturation fluorescence in situ hybridization. Mol Cell 2021; 81:1566-1577.e8. [PMID: 33657402 PMCID: PMC8026568 DOI: 10.1016/j.molcel.2021.02.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 11/22/2020] [Accepted: 02/04/2021] [Indexed: 12/26/2022]
Abstract
Cas9 in complex with a programmable guide RNA targets specific double-stranded DNA for cleavage. By harnessing Cas9 as a programmable loader of superhelicase to genomic DNA, we report a physiological-temperature DNA fluorescence in situ hybridization (FISH) method termed genome oligopaint via local denaturation (GOLD) FISH. Instead of global denaturation as in conventional DNA FISH, loading a superhelicase at a Cas9-generated nick allows for local DNA denaturation, reducing nonspecific binding of probes and avoiding harsh treatments such as heat denaturation. GOLD FISH relies on Cas9 cleaving target DNA sequences and avoids the high nuclear background associated with other genome labeling methods that rely on Cas9 binding. The excellent signal brightness and specificity enable us to image nonrepetitive genomic DNA loci and analyze the conformational differences between active and inactive X chromosomes. Finally, GOLD FISH could be used for rapid identification of HER2 gene amplification in patient tissue.
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Affiliation(s)
- Yanbo Wang
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Wayne Taylor Cottle
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Haobo Wang
- Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Xinyu Ashlee Feng
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - John Mallon
- Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Momcilo Gavrilov
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Scott Bailey
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Bloomberg School of Public Health, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, USA; Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA.
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49
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Zou RS, Liu Y, Wu B, Ha T. Cas9 deactivation with photocleavable guide RNAs. Mol Cell 2021; 81:1553-1565.e8. [PMID: 33662274 PMCID: PMC8026597 DOI: 10.1016/j.molcel.2021.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 12/23/2020] [Accepted: 02/02/2021] [Indexed: 12/11/2022]
Abstract
Precise control of CRISPR-Cas9 would improve its safety and applicability. Controlled CRISPR inhibition is a promising approach but is complicated by separate inhibitor delivery, incomplete deactivation, and slow kinetics. To overcome these obstacles, we engineered photocleavable guide RNAs (pcRNAs) that endow Cas9 nucleases and base editors with a built-in mechanism for light-based deactivation. pcRNA enabled the fastest (<1 min) and most complete (<1% residual indels) approach for Cas9 deactivation. It also exhibited significantly enhanced specificity with wild-type Cas9. Time-resolved deactivation revealed that 12-36 h of Cas9 activity or 2-4 h of base editor activity was sufficient to achieve high editing efficiency. pcRNA is useful for studies of the cellular response to DNA damage by abolishing sustained cycles of damage and repair that would otherwise desynchronize response trajectories. Together, pcRNA expands the CRISPR toolbox for precision genome editing and studies of DNA damage and repair.
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Affiliation(s)
- Roger S Zou
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Yang Liu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Bin Wu
- Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA
| | - Taekjip Ha
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics and Biophysical Chemistry, Johns Hopkins University, Baltimore, MD 21205, USA; Department of Biophysics, Johns Hopkins University, Baltimore, MD 21205, USA; Howard Hughes Medical Institute, Baltimore, MD 21205, USA.
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50
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Uslu M, Siyah P, Harvey AJ, Kocabaş F. Modulating Cas9 activity for precision gene editing. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2021; 181:89-127. [PMID: 34127203 DOI: 10.1016/bs.pmbts.2021.01.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The CRISPR/Cas9 is a RNA-guided nuclease complex that can be specifically programmed to target a user-specified DNA sequence. It has been a powerful and effective tool of genome editing. However, off-target activity of the Cas9 nuclease limits its potential use in the correction of inherited diseases and bona fide gene editing. Various protein engineering and guide RNA selection strategies have been utilized to improve Cas9-based genome-editing specificity and efficiency. We, however, have not yet achieved a degree of safety such that Cas9 gene editing approaches could be applicable in clinical settings. Here, we discuss the recently developed and precise gene editing technologies based on spCas9. Furthermore, we describe Cas9 modulating tools to increase the fidelity of the CRISPR/Cas9 system. These studies suggest that there is still a need for pharmaceutical modulation of Cas9 activity during gene editing procedures. Pharmaceutical modulation of Cas9 nuclease activity at on-target or off-target genomic loci could 1 day allow researchers to develop robust and precise therapeutical strategies in gene editing.
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Affiliation(s)
- Merve Uslu
- Graduate School of Natural and Applied Sciences, Yeditepe University, Istanbul, Turkey; Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Pınar Siyah
- Graduate School of Natural and Applied Sciences, Yeditepe University, Istanbul, Turkey; Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Andrew John Harvey
- Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey
| | - Fatih Kocabaş
- Graduate School of Natural and Applied Sciences, Yeditepe University, Istanbul, Turkey; Department of Genetics and Bioengineering, Faculty of Engineering, Yeditepe University, Istanbul, Turkey.
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