1
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Strohkendl I, Saha A, Moy C, Nguyen AH, Ahsan M, Russell R, Palermo G, Taylor DW. Cas12a domain flexibility guides R-loop formation and forces RuvC resetting. Mol Cell 2024; 84:2717-2731.e6. [PMID: 38955179 PMCID: PMC11283365 DOI: 10.1016/j.molcel.2024.06.007] [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: 09/11/2023] [Revised: 05/17/2024] [Accepted: 06/07/2024] [Indexed: 07/04/2024]
Abstract
The specific nature of CRISPR-Cas12a makes it a desirable RNA-guided endonuclease for biotechnology and therapeutic applications. To understand how R-loop formation within the compact Cas12a enables target recognition and nuclease activation, we used cryo-electron microscopy to capture wild-type Acidaminococcus sp. Cas12a R-loop intermediates and DNA delivery into the RuvC active site. Stages of Cas12a R-loop formation-starting from a 5-bp seed-are marked by distinct REC domain arrangements. Dramatic domain flexibility limits contacts until nearly complete R-loop formation, when the non-target strand is pulled across the RuvC nuclease and coordinated domain docking promotes efficient cleavage. Next, substantial domain movements enable target strand repositioning into the RuvC active site. Between cleavage events, the RuvC lid conformationally resets to occlude the active site, requiring re-activation. These snapshots build a structural model depicting Cas12a DNA targeting that rationalizes observed specificity and highlights mechanistic comparisons to other class 2 effectors.
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Affiliation(s)
- Isabel Strohkendl
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Aakash Saha
- Department of Bioengineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Catherine Moy
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Alexander-Hoi Nguyen
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Mohd Ahsan
- Department of Bioengineering, University of California, Riverside, Riverside, CA 92521, USA
| | - Rick Russell
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX 78712, USA
| | - Giulia Palermo
- Department of Bioengineering, University of California, Riverside, Riverside, CA 92521, USA; Department of Chemistry, University of California, Riverside, Riverside, CA 92521, USA
| | - David W Taylor
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; LIVESTRONG Cancer Institute, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA.
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2
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Irmisch P, Mogila I, Samatanga B, Tamulaitis G, Seidel R. Retention of the RNA ends provides the molecular memory for maintaining the activation of the Csm complex. Nucleic Acids Res 2024; 52:3896-3910. [PMID: 38340341 DOI: 10.1093/nar/gkae080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/23/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
The type III CRISPR-Cas effector complex Csm functions as a molecular Swiss army knife that provides multilevel defense against foreign nucleic acids. The coordinated action of three catalytic activities of the Csm complex enables simultaneous degradation of the invader's RNA transcripts, destruction of the template DNA and synthesis of signaling molecules (cyclic oligoadenylates cAn) that activate auxiliary proteins to reinforce CRISPR-Cas defense. Here, we employed single-molecule techniques to connect the kinetics of RNA binding, dissociation, and DNA hydrolysis by the Csm complex from Streptococcus thermophilus. Although single-stranded RNA is cleaved rapidly (within seconds), dual-color FCS experiments and single-molecule TIRF microscopy revealed that Csm remains bound to terminal RNA cleavage products with a half-life of over 1 hour while releasing the internal RNA fragments quickly. Using a continuous fluorescent DNA degradation assay, we observed that RNA-regulated single-stranded DNase activity decreases on a similar timescale. These findings suggest that after fast target RNA cleavage the terminal RNA cleavage products stay bound within the Csm complex, keeping the Cas10 subunit activated for DNA destruction. Additionally, we demonstrate that during Cas10 activation, the complex remains capable of RNA turnover, i.e. of ongoing degradation of target RNA.
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Affiliation(s)
- Patrick Irmisch
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Irmantas Mogila
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Brighton Samatanga
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Gintautas Tamulaitis
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
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3
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Hu C, Myers MT, Zhou X, Hou Z, Lozen ML, Nam KH, Zhang Y, Ke A. Exploiting activation and inactivation mechanisms in type I-C CRISPR-Cas3 for genome-editing applications. Mol Cell 2024; 84:463-475.e5. [PMID: 38242128 PMCID: PMC10857747 DOI: 10.1016/j.molcel.2023.12.034] [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: 06/20/2023] [Revised: 10/26/2023] [Accepted: 12/21/2023] [Indexed: 01/21/2024]
Abstract
Type I CRISPR-Cas systems utilize the RNA-guided Cascade complex to identify matching DNA targets and the nuclease-helicase Cas3 to degrade them. Among the seven subtypes, type I-C is compact in size and highly active in creating large-sized genome deletions in human cells. Here, we use four cryoelectron microscopy snapshots to define its RNA-guided DNA binding and cleavage mechanisms in high resolution. The non-target DNA strand (NTS) is accommodated by I-C Cascade in a continuous binding groove along the juxtaposed Cas11 subunits. Binding of Cas3 further traps a flexible bulge in NTS, enabling NTS nicking. We identified two anti-CRISPR proteins AcrIC8 and AcrIC9 that strongly inhibit Neisseria lactamica I-C function. Structural analysis showed that AcrIC8 inhibits PAM recognition through allosteric inhibition, whereas AcrIC9 achieves so through direct competition. Both Acrs potently inhibit I-C-mediated genome editing and transcriptional modulation in human cells, providing the first off-switches for type I CRISPR eukaryotic genome engineering.
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Affiliation(s)
- Chunyi Hu
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA; Department of Biological Sciences, Faculty of Science; Department of Biochemistry, Precision Medicine Translational Research Programme (TRP), Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore
| | - Mason T Myers
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Xufei Zhou
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Zhonggang Hou
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Macy L Lozen
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Ki Hyun Nam
- College of General Education, Kookmin University, Seoul 02707, Republic of Korea
| | - Yan Zhang
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA.
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4
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Santiago-Frangos A, Henriques WS, Wiegand T, Gauvin CC, Buyukyoruk M, Graham AB, Wilkinson RA, Triem L, Neselu K, Eng ET, Lander GC, Wiedenheft B. Structure reveals why genome folding is necessary for site-specific integration of foreign DNA into CRISPR arrays. Nat Struct Mol Biol 2023; 30:1675-1685. [PMID: 37710013 PMCID: PMC10872659 DOI: 10.1038/s41594-023-01097-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 08/15/2023] [Indexed: 09/16/2023]
Abstract
Bacteria and archaea acquire resistance to viruses and plasmids by integrating fragments of foreign DNA into the first repeat of a CRISPR array. However, the mechanism of site-specific integration remains poorly understood. Here, we determine a 560-kDa integration complex structure that explains how Pseudomonas aeruginosa Cas (Cas1-Cas2/3) and non-Cas proteins (for example, integration host factor) fold 150 base pairs of host DNA into a U-shaped bend and a loop that protrude from Cas1-2/3 at right angles. The U-shaped bend traps foreign DNA on one face of the Cas1-2/3 integrase, while the loop places the first CRISPR repeat in the Cas1 active site. Both Cas3 proteins rotate 100 degrees to expose DNA-binding sites on either side of the Cas2 homodimer, which each bind an inverted repeat motif in the leader. Leader sequence motifs direct Cas1-2/3-mediated integration to diverse repeat sequences that have a 5'-GT. Collectively, this work reveals new DNA-binding surfaces on Cas2 that are critical for DNA folding and site-specific delivery of foreign DNA.
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Affiliation(s)
| | - William S Henriques
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Tanner Wiegand
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Colin C Gauvin
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT, USA
- Thermal Biology Institute, Montana State University, Bozeman, MT, USA
| | - Murat Buyukyoruk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Ava B Graham
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Royce A Wilkinson
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Lenny Triem
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Kasahun Neselu
- Simons Electron Microscopy Center, National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, NY, USA
| | - Edward T Eng
- Simons Electron Microscopy Center, National Resource for Automated Molecular Microscopy, New York Structural Biology Center, New York, NY, USA
| | - Gabriel C Lander
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Blake Wiedenheft
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
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5
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Tang D, Jia T, Luo Y, Mou B, Cheng J, Qi S, Yao S, Su Z, Yu Y, Chen Q. DnaQ mediates directional spacer acquisition in the CRISPR-Cas system by a time-dependent mechanism. Innovation (N Y) 2023; 4:100495. [PMID: 37663930 PMCID: PMC10470216 DOI: 10.1016/j.xinn.2023.100495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 08/06/2023] [Indexed: 09/05/2023] Open
Abstract
In the spacer acquisition stage of CRISPR-Cas immunity, spacer orientation and protospacer adjacent motif (PAM) removal are two prerequisites for functional spacer integration. Cas4 has been implicated in both processing the prespacer and determining the spacer orientation. In Cas4-lacking systems, host 3'-5' DnaQ family exonucleases were recently reported to play a Cas4-like role. However, the molecular details of DnaQ functions remain elusive. Here, we characterized the spacer acquisition of the adaptation module of the Streptococcus thermophilus type I-E system, in which a DnaQ domain naturally fuses with Cas2. We presented X-ray crystal structures and cryo-electron microscopy structures of this adaptation module. Our biochemical data showed that DnaQ trimmed PAM-containing and PAM-deficient overhangs with different efficiencies. Based on these results, we proposed a time-dependent model for DnaQ-mediated spacer acquisition to elucidate PAM removal and spacer orientation determination in Cas4-lacking CRISPR-Cas systems.
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Affiliation(s)
- Dongmei Tang
- Department of Urology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tingting Jia
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yongbo Luo
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Biqin Mou
- Precision Medicine Center, Precision Medicine Key Laboratory of Sichuan Province, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jie Cheng
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shiqian Qi
- Department of Urology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Shaohua Yao
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zhaoming Su
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yamei Yu
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Qiang Chen
- Department of Biotherapy, Cancer Center and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, China
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6
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Jiang Z, Lin Z, Gan Q, Wu P, Zhang X, Xiao Y, She Q, Ni J, Shen Y, Huang Q. The FHA domain protein ArnA functions as a global DNA damage response repressor in the hyperthermophilic archaeon Saccharolobus islandicus. mBio 2023; 14:e0094223. [PMID: 37389462 PMCID: PMC10470591 DOI: 10.1128/mbio.00942-23] [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: 04/18/2023] [Accepted: 05/18/2023] [Indexed: 07/01/2023] Open
Abstract
Forkhead-associated (FHA) domain proteins specifically recognize phosphorylated threonine via the FHA domain and are involved in signal transduction in various processes especially DNA damage response (DDR) and cell cycle regulation in eukaryotes. Although FHA domain proteins are found in prokaryotes, archaea, and bacteria, their functions are far less clear as compared to the eukaryotic counterparts, and it has not been studied whether archaeal FHA proteins play a role in DDR. Here, we have characterized an FHA protein from the hyperthermophilic Crenarchaeon Saccharolobus islandicus (SisArnA) by genetic, biochemical, and transcriptomic approaches. We find that ΔSisarnA exhibits higher resistance to DNA damage agent 4-nitroquinoline 1-oxide (NQO). The transcription of ups genes, encoding the proteins for pili-mediated cell aggregation and cell survival after DDR, is elevated in ΔSisarnA. The interactions of SisArnA with two predicted partners, SisvWA1 (SisArnB) and SisvWA2 (designated as SisArnE), were enhanced by phosphorylation in vitro. ΔSisarnB displays higher resistance to NQO than the wild type. In addition, the interaction between SisArnA and SisArnB, which is reduced in the NQO-treated cells, is indispensable for DNA binding in vitro. These indicate that SisArnA and SisArnB work together to inhibit the expression of ups genes in vivo. Interestingly, ΔSisarnE is more sensitive to NQO than the wild type, and the interaction between SisArnA and SisArnE is strengthened after NQO treatment, suggesting a positive role of SisArnE in DDR. Finally, transcriptomic analysis reveals that SisArnA represses a number of genes, implying that archaea apply the FHA/phospho-peptide recognition module for extensive transcriptional regulation. IMPORTANCE Cellular adaption to diverse environmental stresses requires a signal sensor and transducer for cell survival. Protein phosphorylation and its recognition by forkhead-associated (FHA) domain proteins are widely used for signal transduction in eukaryotes. Although FHA proteins exist in archaea and bacteria, investigation of their functions, especially those in DNA damage response (DDR), is limited. Therefore, the evolution and functional conservation of FHA proteins in the three domains of life is still a mystery. Here, we find that an FHA protein from the hyperthermophilic Crenarchaeon Saccharolobus islandicus (SisArnA) represses the transcription of pili genes together with its phosphorylated partner SisArnB. SisArnA derepression facilitates DNA exchange and repair in the presence of DNA damage. The fact that more genes including a dozen of those involved in DDR are found to be regulated by SisArnA implies that the FHA/phosphorylation module may serve as an important signal transduction pathway for transcriptional regulation in archaeal DDR.
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Affiliation(s)
- Zhichao Jiang
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Zijia Lin
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Qi Gan
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Pengju Wu
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Xuemei Zhang
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yuanxi Xiao
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Qunxin She
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Jinfeng Ni
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Yulong Shen
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
| | - Qihong Huang
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Microbial Technology Institute, Shandong University, Qingdao, China
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7
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Hu C, Myers MT, Zhou X, Hou Z, Lozen ML, Zhang Y, Ke A. Exploiting Activation and Inactivation Mechanisms in Type I-C CRISPR-Cas3 for Genome Editing Applications. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.05.552134. [PMID: 37577534 PMCID: PMC10418205 DOI: 10.1101/2023.08.05.552134] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Type I CRISPR-Cas systems utilize the RNA-guided Cascade complex to identify matching DNA targets, and the nuclease-helicase Cas3 to degrade them. Among seven subtypes, Type I-C is compact in size and highly active in creating large-sized genome deletions in human cells. Here we use four cryo-electron microscopy snapshots to define its RNA-guided DNA binding and cleavage mechanisms in high resolution. The non-target DNA strand (NTS) is accommodated by I-C Cascade in a continuous binding groove along the juxtaposed Cas11 subunits. Binding of Cas3 further traps a flexible bulge in NTS, enabling efficient NTS nicking. We identified two anti-CRISPR proteins AcrIC8 and AcrIC9, that strongly inhibit N. lactamica I-C function. Structural analysis showed that AcrIC8 inhibits PAM recognition through direct competition, whereas AcrIC9 achieves so through allosteric inhibition. Both Acrs potently inhibit I-C-mediated genome editing and transcriptional modulation in human cells, providing the first off-switches for controllable Type I CRISPR genome engineering.
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8
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Shangguan Q, White MF. Repurposing the atypical type I-G CRISPR system for bacterial genome engineering. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001373. [PMID: 37526970 PMCID: PMC10482374 DOI: 10.1099/mic.0.001373] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/18/2023] [Indexed: 08/02/2023]
Abstract
The CRISPR-Cas system functions as a prokaryotic immune system and is highly diverse, with six major types and numerous sub-types. The most abundant are type I CRISPR systems, which utilize a multi-subunit effector, Cascade, and a CRISPR RNA (crRNA) to detect invading DNA species. Detection leads to DNA loading of the Cas3 helicase-nuclease, leading to long-range deletions in the targeted DNA, thus providing immunity against mobile genetic elements (MGE). Here, we focus on the type I-G system, a streamlined, 4-subunit complex with an atypical Cas3 enzyme. We demonstrate that Cas3 helicase activity is not essential for immunity against MGE in vivo and explore applications of the Thioalkalivibrio sulfidiphilus Cascade effector for genome engineering in Escherichia coli. Long-range, bidirectional deletions were observed when the lacZ gene was targeted. Deactivation of the Cas3 helicase activity dramatically altered the types of deletions observed, with small deletions flanked by direct repeats that are suggestive of microhomology mediated end joining. When donor DNA templates were present, both the wild-type and helicase-deficient systems promoted homology-directed repair (HDR), with the latter system providing improvements in editing efficiency, suggesting that a single nick in the target site may promote HDR in E. coli using the type I-G system. These findings open the way for further application of the type I-G CRISPR systems in genome engineering.
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Affiliation(s)
- Qilin Shangguan
- School of Biology, Biomedical Sciences Research Complex, University of St Andrews, St Andrews, UK
| | - Malcolm F. White
- School of Biology, Biomedical Sciences Research Complex, University of St Andrews, St Andrews, UK
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9
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CRISPR-Cas adaptation in Escherichia coli. Biosci Rep 2023; 43:232582. [PMID: 36809461 PMCID: PMC10011333 DOI: 10.1042/bsr20221198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 02/20/2023] [Accepted: 02/21/2023] [Indexed: 02/23/2023] Open
Abstract
Prokaryotes use the adaptive immunity mediated via the Clustered Regularly Interspaced Short Palindromic Repeats and CRISPR associated (CRISPR-Cas) system for protection against invading elements such as phages and plasmids. The immunity is achieved by capturing small DNA fragments or spacers from foreign nucleic acids (protospacers) and integrating them into the host CRISPR locus. This step of CRISPR-Cas immunity called 'naïve CRISPR adaptation' requires the conserved Cas1-Cas2 complex and is often supported by variable host proteins that assist in spacer processing and integration. Bacteria that have acquired new spacers become immune to the same invading elements when reinfected. CRISPR-Cas immunity can also be updated by integrating new spacers from the same invading elements, a process called 'primed adaptation'. Only properly selected and integrated spacers are functional in the next steps of CRISPR immunity when their processed transcripts are used for RNA-guided target recognition and interference (target degradation). Capturing, trimming, and integrating new spacers in the correct orientation are universal steps of adaptation to all CRISPR-Cas systems, but some details are CRISPR-Cas type-specific and species-specific. In this review, we provide an overview of the mechanisms of CRISPR-Cas class 1 type I-E adaptation in Escherichia coli as a general model for adaptation processes (DNA capture and integration) that have been studied in detail. We focus on the role of host non-Cas proteins involved in adaptation, particularly on the role of homologous recombination.
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10
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O'Brien RE, Bravo JPK, Ramos D, Hibshman GN, Wright JT, Taylor DW. Structural snapshots of R-loop formation by a type I-C CRISPR Cascade. Mol Cell 2023; 83:746-758.e5. [PMID: 36805026 PMCID: PMC10026943 DOI: 10.1016/j.molcel.2023.01.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/12/2022] [Accepted: 01/26/2023] [Indexed: 02/18/2023]
Abstract
Type I CRISPR-Cas systems employ multi-subunit Cascade effector complexes to target foreign nucleic acids for destruction. Here, we present structures of D. vulgaris type I-C Cascade at various stages of double-stranded (ds)DNA target capture, revealing mechanisms that underpin PAM recognition and Cascade allosteric activation. We uncover an interesting mechanism of non-target strand (NTS) DNA stabilization via stacking interactions with the "belly" subunits, securing the NTS in place. This "molecular seatbelt" mechanism facilitates efficient R-loop formation and prevents dsDNA reannealing. Additionally, we provide structural insights into how two anti-CRISPR (Acr) proteins utilize distinct strategies to achieve a shared mechanism of type I-C Cascade inhibition by blocking PAM scanning. These observations form a structural basis for directional R-loop formation and reveal how different Acr proteins have converged upon common molecular mechanisms to efficiently shut down CRISPR immunity.
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Affiliation(s)
- Roisin E O'Brien
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX 78712, USA
| | - Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Delisa Ramos
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Grace N Hibshman
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX 78712, USA
| | - Jacquelyn T Wright
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX 78712, USA
| | - David W Taylor
- Interdisciplinary Life Sciences Graduate Programs, University of Texas at Austin, Austin, TX 78712, USA; Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA; Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA; LIVESTRONG Cancer Institutes, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA.
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11
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Yang H, Zhang Y, Teng X, Hou H, Deng R, Li J. CRISPR-based nucleic acid diagnostics for pathogens. Trends Analyt Chem 2023; 160:116980. [PMID: 36818498 PMCID: PMC9922438 DOI: 10.1016/j.trac.2023.116980] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2022] [Revised: 12/28/2022] [Accepted: 02/09/2023] [Indexed: 02/17/2023]
Abstract
Pathogenic infection remains the primary threat to human health, such as the global COVID-19 pandemic. It is important to develop rapid, sensitive and multiplexed tools for detecting pathogens and their mutated variants, particularly the tailor-made strategies for point-of-care diagnosis allowing for use in resource-constrained settings. The rapidly evolving CRISPR/Cas systems have provided a powerful toolbox for pathogenic diagnostics via nucleic acid tests. In this review, we firstly describe the resultant promising class 2 (single, multidomain effector) and recently explored class 1 (multisubunit effector complexes) CRISPR tools. We present diverse engineering nucleic acid diagnostics based on CRISPR/Cas systems for pathogenic viruses, bacteria and fungi, and highlight the application for detecting viral variants and drug-resistant bacteria enabled by CRISPR-based mutation profiling. Finally, we discuss the challenges involved in on-site diagnostic assays and present emerging CRISPR systems and CRISPR cascade that potentially enable multiplexed and preamplification-free pathogenic diagnostics.
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Affiliation(s)
- Hao Yang
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan, 610065, China,Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
| | - Yong Zhang
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Xucong Teng
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China
| | - Hongwei Hou
- China National Tobacco Quality Supervision & Test Center, Zhengzhou, 450003, China,Beijing Institute of Life Science and Technology, Beijing, 102206, China
| | - Ruijie Deng
- College of Biomass Science and Engineering, Healthy Food Evaluation Research Center, Sichuan University, Chengdu, Sichuan, 610065, China,Corresponding author
| | - Jinghong Li
- Department of Chemistry, Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, Tsinghua University, Beijing, 100084, China,Corresponding author
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12
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He L, Lever R, Cubbon A, Tehseen M, Jenkins T, Nottingham AO, Horton A, Betts H, Fisher M, Hamdan SM, Soultanas P, Bolt EL. Interaction of human HelQ with DNA polymerase delta halts DNA synthesis and stimulates DNA single-strand annealing. Nucleic Acids Res 2023; 51:1740-1749. [PMID: 36718939 PMCID: PMC9976902 DOI: 10.1093/nar/gkad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 02/01/2023] Open
Abstract
DNA strand breaks are repaired by DNA synthesis from an exposed DNA end paired with a homologous DNA template. DNA polymerase delta (Pol δ) catalyses DNA synthesis in multiple eukaryotic DNA break repair pathways but triggers genome instability unless its activity is restrained. We show that human HelQ halts DNA synthesis by isolated Pol δ and Pol δ-PCNA-RPA holoenzyme. Using novel HelQ mutant proteins we identify that inhibition of Pol δ is independent of DNA binding, and maps to a 70 amino acid intrinsically disordered region of HelQ. Pol δ and its POLD3 subunit robustly stimulated DNA single-strand annealing by HelQ, and POLD3 and HelQ interact physically via the intrinsically disordered HelQ region. This data, and inability of HelQ to inhibit DNA synthesis by the POLD1 catalytic subunit of Pol δ, reveal a mechanism for limiting DNA synthesis and promoting DNA strand annealing during human DNA break repair, which centres on POLD3.
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Affiliation(s)
- Liu He
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Rebecca Lever
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Andrew Cubbon
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Muhammad Tehseen
- Bioscience Program, Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Tabitha Jenkins
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | | | - Anya Horton
- School of Life Sciences, University of Nottingham, Nottingham, UK
| | - Hannah Betts
- Biodiscovery Institute, School of Chemistry, University of Nottingham, Nottingham, UK
| | | | - Samir M Hamdan
- Bioscience Program, Biological and Environmental Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Panos Soultanas
- Biodiscovery Institute, School of Chemistry, University of Nottingham, Nottingham, UK
| | - Edward L Bolt
- School of Life Sciences, University of Nottingham, Nottingham, UK
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13
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Crickard JB. Single Molecule Imaging of DNA-Protein Interactions Using DNA Curtains. Methods Mol Biol 2023; 2599:127-139. [PMID: 36427147 PMCID: PMC10082465 DOI: 10.1007/978-1-0716-2847-8_10] [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: 11/26/2022]
Abstract
Direct observation of enzymes that work to promote nucleic acid metabolism is a powerful approach to understanding their biochemical and biological properties. Over several years, fluorescent optical microscopy has developed as a powerful tool for watching biological pathways as they occur in real time. Here we describe DNA curtains as an optical microscopy tool that combines engineering, biochemistry, and single molecule imaging to make direct observations of enzymes as they work on DNA in real time. We will provide a detailed methodology of this approach including information about the setup of a basic TIRF microscope, assembly of flow chambers for imaging, and the protocol for making DNA curtains. Our goal is to help the reader better understand the technical approaches to DNA curtains and to better understand the biochemical and biological applications of this approach.
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Affiliation(s)
- J Brooks Crickard
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA.
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14
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Shiriaeva AA, Kuznedelov K, Fedorov I, Musharova O, Khvostikov T, Tsoy Y, Kurilovich E, Smith GR, Semenova E, Severinov K. Host nucleases generate prespacers for primed adaptation in the E. coli type I-E CRISPR-Cas system. SCIENCE ADVANCES 2022; 8:eabn8650. [PMID: 36427302 PMCID: PMC9699676 DOI: 10.1126/sciadv.abn8650] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
CRISPR-Cas systems provide prokaryotes with adaptive immunity against foreign nucleic acids. In Escherichia coli, immunity is acquired upon integration of 33-bp spacers into CRISPR arrays. DNA targets complementary to spacers get degraded and serve as a source of new spacers during a process called primed adaptation. Precursors of such spacers, prespacers, are ~33-bp double-stranded DNA fragments with a ~4-nt 3' overhang. The mechanism of prespacer generation is not clear. Here, we use FragSeq and biochemical approaches to determine enzymes involved in generation of defined prespacer ends. We demonstrate that RecJ is the main exonuclease trimming 5' ends of prespacer precursors, although its activity can be partially substituted by ExoVII. The RecBCD complex allows single strand-specific RecJ to process double-stranded regions flanking prespacers. Our results reveal intricate functional interactions of genome maintenance proteins with CRISPR interference and adaptation machineries during generation of prespacers capable of integration into CRISPR arrays.
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Affiliation(s)
- Anna A. Shiriaeva
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
- Saint Petersburg State University, Saint Petersburg 199034, Russia
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg 195251, Russia
- Waksman Institute, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
| | - Konstantin Kuznedelov
- Waksman Institute, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
| | - Ivan Fedorov
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
- Institute of Gene Biology, Russian Academy of Science, Moscow 119334, Russia
| | - Olga Musharova
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
- Institute of Molecular Genetics, National Research Center Kurchatov Institute, Moscow 123182, Russia
| | - Timofey Khvostikov
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Yuliya Tsoy
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg 195251, Russia
| | - Elena Kurilovich
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Gerald R. Smith
- Division of Basic Sciences, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Ekaterina Semenova
- Waksman Institute, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
| | - Konstantin Severinov
- Waksman Institute, Rutgers, State University of New Jersey, Piscataway, NJ 08854, USA
- Institute of Molecular Genetics, National Research Center Kurchatov Institute, Moscow 123182, Russia
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15
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Wang JY, Pausch P, Doudna JA. Structural biology of CRISPR-Cas immunity and genome editing enzymes. Nat Rev Microbiol 2022; 20:641-656. [PMID: 35562427 DOI: 10.1038/s41579-022-00739-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/11/2022] [Indexed: 12/20/2022]
Abstract
CRISPR-Cas systems provide resistance against foreign mobile genetic elements and have a wide range of genome editing and biotechnological applications. In this Review, we examine recent advances in understanding the molecular structures and mechanisms of enzymes comprising bacterial RNA-guided CRISPR-Cas immune systems and deployed for wide-ranging genome editing applications. We explore the adaptive and interference aspects of CRISPR-Cas function as well as open questions about the molecular mechanisms responsible for genome targeting. These structural insights reflect close evolutionary links between CRISPR-Cas systems and mobile genetic elements, including the origins and evolution of CRISPR-Cas systems from DNA transposons, retrotransposons and toxin-antitoxin modules. We discuss how the evolution and structural diversity of CRISPR-Cas systems explain their functional complexity and utility as genome editing tools.
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Affiliation(s)
- Joy Y Wang
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
| | - Patrick Pausch
- VU LSC-EMBL Partnership for Genome Editing Technologies, Life Sciences Center, Vilnius University, Vilnius, Lithuania.
| | - Jennifer A Doudna
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA.
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
- Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA, USA.
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA.
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, Berkeley, CA, USA.
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Gladstone Institutes, University of California, San Francisco, San Francisco, CA, USA.
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA.
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16
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Yoshimi K, Takeshita K, Kodera N, Shibumura S, Yamauchi Y, Omatsu M, Umeda K, Kunihiro Y, Yamamoto M, Mashimo T. Dynamic mechanisms of CRISPR interference by Escherichia coli CRISPR-Cas3. Nat Commun 2022; 13:4917. [PMID: 36042215 PMCID: PMC9427990 DOI: 10.1038/s41467-022-32618-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/09/2022] [Indexed: 11/09/2022] Open
Abstract
Type I CRISPR-Cas3 uses an RNA-guided multi Cas-protein complex, Cascade, which detects and degrades foreign nucleic acids via the helicase-nuclease Cas3 protein. Despite many studies using cryoEM and smFRET, the precise mechanism of Cas3-mediated cleavage and degradation of target DNA remains elusive. Here we reconstitute the CRISPR-Cas3 system in vitro to show how the Escherichia coli Cas3 (EcoCas3) with EcoCascade exhibits collateral non-specific single-stranded DNA (ssDNA) cleavage and target specific DNA degradation. Partial binding of EcoCascade to target DNA with tolerated mismatches within the spacer sequence, but not the PAM, elicits collateral ssDNA cleavage activity of recruited EcoCas3. Conversely, stable binding with complete R-loop formation drives EcoCas3 to nick the non-target strand (NTS) in the bound DNA. Helicase-dependent unwinding then combines with trans ssDNA cleavage of the target strand and repetitive cis cleavage of the NTS to degrade the target double-stranded DNA (dsDNA) substrate. High-speed atomic force microscopy demonstrates that EcoCas3 bound to EcoCascade repeatedly reels and releases the target DNA, followed by target fragmentation. Together, these results provide a revised model for collateral ssDNA cleavage and target dsDNA degradation by CRISPR-Cas3, furthering understanding of type I CRISPR priming and interference and informing future genome editing tools.
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Affiliation(s)
- Kazuto Yoshimi
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.,Division of Genome Engineering, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan
| | - Kohei Takeshita
- Life Science Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan
| | - Noriyuki Kodera
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | | | - Yuko Yamauchi
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan
| | - Mine Omatsu
- Life Science Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan.,Laboratory of Macromolecular Dynamics and X-ray Crystallography, Department of Life Science, University of Hyogo, Hyogo, 678-1297, Japan
| | - Kenichi Umeda
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kakuma-machi, Kanazawa, 920-1192, Japan
| | | | - Masaki Yamamoto
- Life Science Research Infrastructure Group, Advanced Photon Technology Division, RIKEN SPring-8 Center, Hyogo, 679-5148, Japan.,Laboratory of Macromolecular Dynamics and X-ray Crystallography, Department of Life Science, University of Hyogo, Hyogo, 678-1297, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan. .,Division of Genome Engineering, Center for Experimental Medicine and Systems Biology, Institute of Medical Science, University of Tokyo, Tokyo, 108-8639, Japan.
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17
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Hu C, Ni D, Nam KH, Majumdar S, McLean J, Stahlberg H, Terns MP, Ke A. Allosteric control of type I-A CRISPR-Cas3 complexes and establishment as effective nucleic acid detection and human genome editing tools. Mol Cell 2022; 82:2754-2768.e5. [PMID: 35835111 PMCID: PMC9357151 DOI: 10.1016/j.molcel.2022.06.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 04/08/2022] [Accepted: 06/06/2022] [Indexed: 12/26/2022]
Abstract
Type I CRISPR-Cas systems typically rely on a two-step process to degrade DNA. First, an RNA-guided complex named Cascade identifies the complementary DNA target. The helicase-nuclease fusion enzyme Cas3 is then recruited in trans for processive DNA degradation. Contrary to this model, here, we show that type I-A Cascade and Cas3 function as an integral effector complex. We provide four cryoelectron microscopy (cryo-EM) snapshots of the Pyrococcus furiosus (Pfu) type I-A effector complex in different stages of DNA recognition and degradation. The HD nuclease of Cas3 is autoinhibited inside the effector complex. It is only allosterically activated upon full R-loop formation, when the entire targeted region has been validated by the RNA guide. The mechanistic insights inspired us to convert Pfu Cascade-Cas3 into a high-sensitivity, low-background, and temperature-activated nucleic acid detection tool. Moreover, Pfu CRISPR-Cas3 shows robust bi-directional deletion-editing activity in human cells, which could find usage in allele-specific inactivation of disease-causing mutations.
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Affiliation(s)
- Chunyi Hu
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA
| | - Dongchun Ni
- Laboratory of Biological Electron Microscopy, Institute of Physics, Faculty of Basic Sciences, Swiss Federal Institute of Technology (EPFL), Cubotron, Route de la Sorge, 1015 Lausanne, Switzerland; Department of Fundamental Biology, Faculty of Biology and Medicine, University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Ki Hyun Nam
- Department of Life Science, Pohang University of Science and Technology, Pohang, Gyeongbuk, Republic of Korea
| | - Sonali Majumdar
- Department of Biochemistry and Molecular Biology, Department of Genetics, and Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Justin McLean
- Department of Biochemistry and Molecular Biology, Department of Genetics, and Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Henning Stahlberg
- Laboratory of Biological Electron Microscopy, Institute of Physics, Faculty of Basic Sciences, Swiss Federal Institute of Technology (EPFL), Cubotron, Route de la Sorge, 1015 Lausanne, Switzerland; Department of Fundamental Biology, Faculty of Biology and Medicine, University of Lausanne (UNIL), 1011 Lausanne, Switzerland
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, Department of Genetics, and Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA.
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18
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Structural rearrangements allow nucleic acid discrimination by type I-D Cascade. Nat Commun 2022; 13:2829. [PMID: 35595728 PMCID: PMC9123187 DOI: 10.1038/s41467-022-30402-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 04/27/2022] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems are adaptive immune systems that protect prokaryotes from foreign nucleic acids, such as bacteriophages. Two of the most prevalent CRISPR-Cas systems include type I and type III. Interestingly, the type I-D interference proteins contain characteristic features of both type I and type III systems. Here, we present the structures of type I-D Cascade bound to both a double-stranded (ds)DNA and a single-stranded (ss)RNA target at 2.9 and 3.1 Å, respectively. We show that type I-D Cascade is capable of specifically binding ssRNA and reveal how PAM recognition of dsDNA targets initiates long-range structural rearrangements that likely primes Cas10d for Cas3′ binding and subsequent non-target strand DNA cleavage. These structures allow us to model how binding of the anti-CRISPR protein AcrID1 likely blocks target dsDNA binding via competitive inhibition of the DNA substrate engagement with the Cas10d active site. This work elucidates the unique mechanisms used by type I-D Cascade for discrimination of single-stranded and double stranded targets. Thus, our data supports a model for the hybrid nature of this complex with features of type III and type I systems. I-D CRISPR-Cascade can target both single-stranded and double-stranded nucleic acids. Here, Schwartz et. al determine these structures and reveal large-scale rearrangements that allow for target discrimination and destruction.
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19
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Govindarajan S, Borges A, Karambelkar S, Bondy-Denomy J. Distinct Subcellular Localization of a Type I CRISPR Complex and the Cas3 Nuclease in Bacteria. J Bacteriol 2022; 204:e0010522. [PMID: 35389256 PMCID: PMC9112876 DOI: 10.1128/jb.00105-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 03/17/2022] [Indexed: 12/30/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated (Cas) systems are prokaryotic adaptive immune systems that have been well characterized biochemically, but in vivo spatiotemporal regulation and cell biology remain largely unaddressed. Here, we used fluorescent fusion proteins introduced at the chromosomal CRISPR-Cas locus to study the localization of the type I-F CRISPR-Cas system in Pseudomonas aeruginosa. When lacking a target in the cell, the Cascade complex is broadly nucleoid bound, while Cas3 is diffuse in the cytoplasm. When targeted to an integrated prophage, however, the CRISPR RNA (crRNA)-guided type I-F Cascade complex and a majority of Cas3 molecules in the cell are recruited to a single focus. Nucleoid association of the Csy proteins that form the Cascade complex is crRNA dependent and specifically inhibited by the expression of anti-CRISPR AcrIF2, which blocks protospacer adjacent motif (PAM) binding. The Cas9 nuclease is also nucleoid localized, only when single guide RNA (sgRNA) bound, which is abolished by the PAM-binding inhibitor AcrIIA4. Our findings reveal PAM-dependent nucleoid surveillance and spatiotemporal regulation in type I CRISPR-Cas that separates the nuclease-helicase Cas3 from the crRNA-guided surveillance complex. IMPORTANCE CRISPR-Cas systems, the prokaryotic adaptive immune systems, are largely understood using structural biology, biochemistry, and genetics. How CRISPR-Cas effectors are organized within cells is currently not well understood. By investigating the cell biology of the type I-F CRISPR-Cas system, we show that the surveillance complex, which "patrols" the cell to find targets, is largely nucleoid bound, while Cas3 nuclease is cytoplasmic. Nucleoid localization is also conserved for class 2 CRISPR-Cas single protein effector Cas9. Our observation of differential localization of the surveillance complex and Cas3 reveals a new layer of posttranslational spatiotemporal regulation to prevent autoimmunity.
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Affiliation(s)
- Sutharsan Govindarajan
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA
| | - Adair Borges
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA
| | - Shweta Karambelkar
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA
| | - Joseph Bondy-Denomy
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, USA
- Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, California, USA
- Innovative Genomics Institute, Berkeley, California, USA
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20
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McKenzie RE, Keizer EM, Vink JNA, van Lopik J, Büke F, Kalkman V, Fleck C, Tans SJ, Brouns SJJ. Single cell variability of CRISPR-Cas interference and adaptation. Mol Syst Biol 2022; 18:e10680. [PMID: 35467080 PMCID: PMC10561596 DOI: 10.15252/msb.202110680] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 12/26/2022] Open
Abstract
While CRISPR-Cas defence mechanisms have been studied on a population level, their temporal dynamics and variability in individual cells have remained unknown. Using a microfluidic device, time-lapse microscopy and mathematical modelling, we studied invader clearance in Escherichia coli across multiple generations. We observed that CRISPR interference is fast with a narrow distribution of clearance times. In contrast, for invaders with escaping PAM mutations we found large cell-to-cell variability, which originates from primed CRISPR adaptation. Faster growth and cell division and higher levels of Cascade increase the chance of clearance by interference, while slower growth is associated with increased chances of clearance by priming. Our findings suggest that Cascade binding to the mutated invader DNA, rather than spacer integration, is the main source of priming heterogeneity. The highly stochastic nature of primed CRISPR adaptation implies that only subpopulations of bacteria are able to respond quickly to invading threats. We conjecture that CRISPR-Cas dynamics and heterogeneity at the cellular level are crucial to understanding the strategy of bacteria in their competition with other species and phages.
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Affiliation(s)
- Rebecca E McKenzie
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
- AMOLFAmsterdamThe Netherlands
| | - Emma M Keizer
- Biometris, Department of Mathematical and Statistical MethodsWageningen UniversityWageningenThe Netherlands
| | - Jochem N A Vink
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
| | - Jasper van Lopik
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
| | - Ferhat Büke
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
- AMOLFAmsterdamThe Netherlands
| | - Vera Kalkman
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
| | - Christian Fleck
- Freiburg Center for Data Analysis and Modeling (FDM)Spatial Systems Biology GroupUniversity of FreiburgFreiburgGermany
| | - Sander J Tans
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
- AMOLFAmsterdamThe Netherlands
| | - Stan J J Brouns
- Department of BionanoscienceDelft University of TechnologyDelftThe Netherlands
- Kavli Institute of NanoscienceDelftThe Netherlands
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21
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Tan R, Krueger RK, Gramelspacher MJ, Zhou X, Xiao Y, Ke A, Hou Z, Zhang Y. Cas11 enables genome engineering in human cells with compact CRISPR-Cas3 systems. Mol Cell 2022; 82:852-867.e5. [PMID: 35051351 PMCID: PMC8964063 DOI: 10.1016/j.molcel.2021.12.032] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 11/09/2021] [Accepted: 12/21/2021] [Indexed: 11/28/2022]
Abstract
Leading CRISPR-Cas technologies employ Cas9 and Cas12 enzymes that generate RNA-guided dsDNA breaks. Yet, the most abundant microbial adaptive immune systems, Type I CRISPRs, are under-exploited for eukaryotic applications. Here, we report the adoption of a minimal CRISPR-Cas3 from Neisseria lactamica (Nla) type I-C system to create targeted large deletions in the human genome. RNP delivery of its processive Cas3 nuclease and target recognition complex Cascade can confer ∼95% editing efficiency. Unexpectedly, NlaCascade assembly in bacteria requires internal translation of a hidden component Cas11 from within the cas8 gene. Furthermore, expressing a separately encoded NlaCas11 is the key to enable plasmid- and mRNA-based editing in human cells. Finally, we demonstrate that supplying cas11 is a universal strategy to systematically implement divergent I-C, I-D, and I-B CRISPR-Cas3 editors with compact sizes, distinct PAM preferences, and guide orthogonality. These findings greatly expand our ability to engineer long-range genome edits.
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Affiliation(s)
- Renke Tan
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA,These authors contributed equally
| | - Ryan K Krueger
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA,These authors contributed equally
| | - Max J Gramelspacher
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Xufei Zhou
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
| | - Yibei Xiao
- State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing, China
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
| | - Zhonggang Hou
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
| | - Yan Zhang
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
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22
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Lee H, Sashital DG. Creating memories: molecular mechanisms of CRISPR adaptation. Trends Biochem Sci 2022; 47:464-476. [DOI: 10.1016/j.tibs.2022.02.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/06/2022] [Accepted: 02/07/2022] [Indexed: 12/22/2022]
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23
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Hu C, Ke A. Reconstitution and biochemical characterization of the RNA-guided helicase-nuclease protein Cas3 from type I-A CRISPR–Cas system. Methods Enzymol 2022; 673:405-424. [DOI: 10.1016/bs.mie.2022.03.059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Isaev AB, Musharova OS, Severinov KV. Microbial Arsenal of Antiviral Defenses. Part II. BIOCHEMISTRY (MOSCOW) 2021; 86:449-470. [PMID: 33941066 DOI: 10.1134/s0006297921040064] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Bacteriophages or phages are viruses that infect bacterial cells (for the scope of this review we will also consider viruses that infect Archaea). The constant threat of phage infection is a major force that shapes evolution of microbial genomes. To withstand infection, bacteria had evolved numerous strategies to avoid recognition by phages or to directly interfere with phage propagation inside the cell. Classical molecular biology and genetic engineering had been deeply intertwined with the study of phages and host defenses. Nowadays, owing to the rise of phage therapy, broad application of CRISPR-Cas technologies, and development of bioinformatics approaches that facilitate discovery of new systems, phage biology experiences a revival. This review describes variety of strategies employed by microbes to counter phage infection. In the first part defense associated with cell surface, roles of small molecules, and innate immunity systems relying on DNA modification were discussed. The second part focuses on adaptive immunity systems, abortive infection mechanisms, defenses associated with mobile genetic elements, and novel systems discovered in recent years through metagenomic mining.
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Affiliation(s)
- Artem B Isaev
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, 143028, Russia.
| | - Olga S Musharova
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, 143028, Russia. .,Institute of Molecular Genetics, Moscow, 119334, Russia
| | - Konstantin V Severinov
- Skolkovo Institute of Science and Technology, Skolkovo, Moscow, 143028, Russia. .,Waksman Institute of Microbiology, Piscataway, NJ 08854, USA
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25
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Prespacers formed during primed adaptation associate with the Cas1-Cas2 adaptation complex and the Cas3 interference nuclease-helicase. Proc Natl Acad Sci U S A 2021; 118:2021291118. [PMID: 34035168 PMCID: PMC8179228 DOI: 10.1073/pnas.2021291118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Primed adaptation allows rapid acquisition of protective spacers derived from foreign mobile genetic elements into CRISPR arrays of the host. Primed adaptation requires ongoing CRISPR interference that destroys foreign genetic elements, but the nature of this requirement is unknown. Using the Escherichia coli I-E CRISPR-Cas as a model, we show that prespacers, short fragments of foreign DNA on their way to become incorporated into CRISPR arrays as spacers, are associated with both the adaptation integrase Cas1 and the interference nuclease Cas3, implying physical association of the interference and adaptation machineries during priming. For Type I CRISPR-Cas systems, a mode of CRISPR adaptation named priming has been described. Priming allows specific and highly efficient acquisition of new spacers from DNA recognized (primed) by the Cascade-crRNA (CRISPR RNA) effector complex. Recognition of the priming protospacer by Cascade-crRNA serves as a signal for engaging the Cas3 nuclease–helicase required for both interference and primed adaptation, suggesting the existence of a primed adaptation complex (PAC) containing the Cas1–Cas2 adaptation integrase and Cas3. To detect this complex in vivo, we here performed chromatin immunoprecipitation with Cas3-specific and Cas1-specific antibodies using cells undergoing primed adaptation. We found that prespacers are bound by both Cas1 (presumably, as part of the Cas1–Cas2 integrase) and Cas3, implying direct physical association of the interference and adaptation machineries as part of PAC.
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A Tryptophan 'Gate' in the CRISPR-Cas3 Nuclease Controls ssDNA Entry into the Nuclease Site, That When Removed Results in Nuclease Hyperactivity. Int J Mol Sci 2021; 22:ijms22062848. [PMID: 33799639 PMCID: PMC8001533 DOI: 10.3390/ijms22062848] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/18/2022] Open
Abstract
Cas3 is a ssDNA-targeting nuclease-helicase essential for class 1 prokaryotic CRISPR immunity systems, which has been utilized for genome editing in human cells. Cas3-DNA crystal structures show that ssDNA follows a pathway from helicase domains into a HD-nuclease active site, requiring protein conformational flexibility during DNA translocation. In genetic studies, we had noted that the efficacy of Cas3 in CRISPR immunity was drastically reduced when temperature was increased from 30 °C to 37 °C, caused by an unknown mechanism. Here, using E. coli Cas3 proteins, we show that reduced nuclease activity at higher temperature corresponds with measurable changes in protein structure. This effect of temperature on Cas3 was alleviated by changing a single highly conserved tryptophan residue (Trp-406) into an alanine. This Cas3W406A protein is a hyperactive nuclease that functions independently from temperature and from the interference effector module Cascade. Trp-406 is situated at the interface of Cas3 HD and RecA1 domains that is important for maneuvering DNA into the nuclease active site. Molecular dynamics simulations based on the experimental data showed temperature-induced changes in positioning of Trp-406 that either blocked or cleared the ssDNA pathway. We propose that Trp-406 forms a 'gate' for controlling Cas3 nuclease activity via access of ssDNA to the nuclease active site. The effect of temperature in these experiments may indicate allosteric control of Cas3 nuclease activity caused by changes in protein conformations. The hyperactive Cas3W406A protein may offer improved Cas3-based genetic editing in human cells.
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Strohkendl I, Saifuddin FA, Gibson BA, Rosen MK, Russell R, Finkelstein IJ. Inhibition of CRISPR-Cas12a DNA targeting by nucleosomes and chromatin. SCIENCE ADVANCES 2021; 7:7/11/eabd6030. [PMID: 33692102 PMCID: PMC7946368 DOI: 10.1126/sciadv.abd6030] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 01/22/2021] [Indexed: 06/10/2023]
Abstract
Genome engineering nucleases must access chromatinized DNA. Here, we investigate how AsCas12a cleaves DNA within human nucleosomes and phase-condensed nucleosome arrays. Using quantitative kinetics approaches, we show that dynamic nucleosome unwrapping regulates target accessibility to Cas12a and determines the extent to which both steps of binding-PAM recognition and R-loop formation-are inhibited by the nucleosome. Relaxing DNA wrapping within the nucleosome by reducing DNA bendability, adding histone modifications, or introducing target-proximal dCas9 enhances DNA cleavage rates over 10-fold. Unexpectedly, Cas12a readily cleaves internucleosomal linker DNA within chromatin-like, phase-separated nucleosome arrays. DNA targeting is reduced only ~5-fold due to neighboring nucleosomes and chromatin compaction. This work explains the observation that on-target cleavage within nucleosomes occurs less often than off-target cleavage within nucleosome-depleted genomic regions in cells. We conclude that nucleosome unwrapping regulates accessibility to CRISPR-Cas nucleases and propose that increasing nucleosome breathing dynamics will improve DNA targeting in eukaryotic cells.
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Affiliation(s)
- Isabel Strohkendl
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Fatema A Saifuddin
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
- Department of Cell and Tissue Biology, University of California, San Francisco, 513 Parnassus Ave, San Francisco, CA 94143, USA
| | - Bryan A Gibson
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Michael K Rosen
- Department of Biophysics and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rick Russell
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
| | - Ilya J Finkelstein
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX 78712, USA
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CRISPR-mediated host genomic DNA damage is efficiently repaired through microhomology-mediated end joining in Zymomonas mobilis. J Genet Genomics 2021; 48:115-122. [PMID: 33958317 DOI: 10.1016/j.jgg.2021.02.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 02/07/2021] [Accepted: 02/21/2021] [Indexed: 02/07/2023]
Abstract
CRISPR-Cas systems provide bacteria and archaea with adaptive immunity against mobile genetic elements (MGEs) through uptake of invader-derived spacers. De novo adaptation samples spacers from both invaders and hosts, whereas primed adaptation shows higher specificity to sample spacers from invaders in many model systems as well as in the subtype I-F system of Zymomonas mobilis. Self-derived spacers will lead to CRISPR self-interference. However, our in vivo study demonstrated that this species used the microhomology-mediated end joining (MMEJ) pathway to efficiently repair subtype I-F CRISPR-Cas system-mediated DNA breaks guided by the self-targeting spacers. MMEJ repair of DNA breaks requires direct microhomologous sequences flanking the protospacers and leads to DNA deletions covering the protospacers. Importantly, CRISPR-mediated genomic DNA breaks failed to be repaired via MMEJ pathway in presence of higher copies of short homologous DNA. Moreover, CRISPR-cleaved exogenous plasmid DNA was failed to be repaired through MMEJ pathway, probably due to the inhibition of MMEJ by the presence of higher copies of the plasmid DNA in Z. mobilis. Our results infer that MMEJ pathway discriminates DNA damages between in the host chromosome versus mobile genetic element (MGE) DNA, and maintains genome stability post CRISPR immunity in Z. mobilis.
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Abstract
Prokaryotes have developed numerous defense strategies to combat the constant threat posed by the diverse genetic parasites that endanger them. Clustered regularly interspaced short palindromic repeat (CRISPR)-Cas loci guard their hosts with an adaptive immune system against foreign nucleic acids. Protection starts with an immunization phase, in which short pieces of the invader's genome, known as spacers, are captured and integrated into the CRISPR locus after infection. Next, during the targeting phase, spacers are transcribed into CRISPR RNAs (crRNAs) that guide CRISPR-associated (Cas) nucleases to destroy the invader's DNA or RNA. Here we describe the many different molecular mechanisms of CRISPR targeting and how they are interconnected with the immunization phase through a third phase of the CRISPR-Cas immune response: primed spacer acquisition. In this phase, Cas proteins direct the crRNA-guided acquisition of additional spacers to achieve a more rapid and robust immunization of the population.
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Affiliation(s)
- Philip M. Nussenzweig
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY 10065, USA
| | - Luciano A. Marraffini
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
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O'Brien RE, Santos IC, Wrapp D, Bravo JPK, Schwartz EA, Brodbelt JS, Taylor DW. Structural basis for assembly of non-canonical small subunits into type I-C Cascade. Nat Commun 2020; 11:5931. [PMID: 33230133 PMCID: PMC7684278 DOI: 10.1038/s41467-020-19785-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 10/30/2020] [Indexed: 01/07/2023] Open
Abstract
Bacteria and archaea employ CRISPR (clustered, regularly, interspaced, short palindromic repeats)-Cas (CRISPR-associated) systems as a type of adaptive immunity to target and degrade foreign nucleic acids. While a myriad of CRISPR-Cas systems have been identified to date, type I-C is one of the most commonly found subtypes in nature. Interestingly, the type I-C system employs a minimal Cascade effector complex, which encodes only three unique subunits in its operon. Here, we present a 3.1 Å resolution cryo-EM structure of the Desulfovibrio vulgaris type I-C Cascade, revealing the molecular mechanisms that underlie RNA-directed complex assembly. We demonstrate how this minimal Cascade utilizes previously overlooked, non-canonical small subunits to stabilize R-loop formation. Furthermore, we describe putative PAM and Cas3 binding sites. These findings provide the structural basis for harnessing the type I-C Cascade as a genome-engineering tool.
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Affiliation(s)
- Roisin E O'Brien
- Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Inês C Santos
- Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - Daniel Wrapp
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA
| | - Evan A Schwartz
- Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA
| | - Jennifer S Brodbelt
- Department of Chemistry, University of Texas at Austin, Austin, TX, 78712, USA
| | - David W Taylor
- Institute for Cell and Molecular Biology, University of Texas at Austin, Austin, TX, 78712, USA.
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, 78712, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, 78712, USA.
- Livestrong Cancer Institutes, Dell Medical School, Austin, TX, 78712, USA.
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31
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Zink IA, Wimmer E, Schleper C. Heavily Armed Ancestors: CRISPR Immunity and Applications in Archaea with a Comparative Analysis of CRISPR Types in Sulfolobales. Biomolecules 2020; 10:E1523. [PMID: 33172134 PMCID: PMC7694759 DOI: 10.3390/biom10111523] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022] Open
Abstract
Prokaryotes are constantly coping with attacks by viruses in their natural environments and therefore have evolved an impressive array of defense systems. Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) is an adaptive immune system found in the majority of archaea and about half of bacteria which stores pieces of infecting viral DNA as spacers in genomic CRISPR arrays to reuse them for specific virus destruction upon a second wave of infection. In detail, small CRISPR RNAs (crRNAs) are transcribed from CRISPR arrays and incorporated into type-specific CRISPR effector complexes which further degrade foreign nucleic acids complementary to the crRNA. This review gives an overview of CRISPR immunity to newcomers in the field and an update on CRISPR literature in archaea by comparing the functional mechanisms and abundances of the diverse CRISPR types. A bigger fraction is dedicated to the versatile and prevalent CRISPR type III systems, as tremendous progress has been made recently using archaeal models in discerning the controlled molecular mechanisms of their unique tripartite mode of action including RNA interference, DNA interference and the unique cyclic-oligoadenylate signaling that induces promiscuous RNA shredding by CARF-domain ribonucleases. The second half of the review spotlights CRISPR in archaea outlining seminal in vivo and in vitro studies in model organisms of the euryarchaeal and crenarchaeal phyla, including the application of CRISPR-Cas for genome editing and gene silencing. In the last section, a special focus is laid on members of the crenarchaeal hyperthermophilic order Sulfolobales by presenting a thorough comparative analysis about the distribution and abundance of CRISPR-Cas systems, including arrays and spacers as well as CRISPR-accessory proteins in all 53 genomes available to date. Interestingly, we find that CRISPR type III and the DNA-degrading CRISPR type I complexes co-exist in more than two thirds of these genomes. Furthermore, we identified ring nuclease candidates in all but two genomes and found that they generally co-exist with the above-mentioned CARF domain ribonucleases Csx1/Csm6. These observations, together with published literature allowed us to draft a working model of how CRISPR-Cas systems and accessory proteins cross talk to establish native CRISPR anti-virus immunity in a Sulfolobales cell.
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32
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Garrett S, Shiimori M, Watts EA, Clark L, Graveley BR, Terns MP. Primed CRISPR DNA uptake in Pyrococcus furiosus. Nucleic Acids Res 2020; 48:6120-6135. [PMID: 32421777 PMCID: PMC7293040 DOI: 10.1093/nar/gkaa381] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2020] [Revised: 04/15/2020] [Accepted: 05/11/2020] [Indexed: 12/19/2022] Open
Abstract
CRISPR-Cas adaptive immune systems are used by prokaryotes to defend against invaders like viruses and other mobile genetic elements. Immune memories are stored in the form of 'spacers' which are short DNA sequences that are captured from invaders and added to the CRISPR array during a process called 'adaptation'. Spacers are transcribed and the resulting CRISPR (cr)RNAs assemble with different Cas proteins to form effector complexes that recognize matching nucleic acid and destroy it ('interference'). Adaptation can be 'naïve', i.e. independent of any existing spacer matches, or it can be 'primed', i.e. spurred by the crRNA-mediated detection of a complete or partial match to an invader sequence. Here we show that primed adaptation occurs in Pyrococcus furiosus. Although P. furiosus has three distinct CRISPR-Cas interference systems (I-B, I-A and III-B), only the I-B system and Cas3 were necessary for priming. Cas4, which is important for selection and processing of new spacers in naïve adaptation, was also essential for priming. Loss of either the I-B effector proteins or Cas3 reduced naïve adaptation. However, when Cas3 and all crRNP genes were deleted, uptake of correctly processed spacers was observed, indicating that none of these interference proteins are necessary for naïve adaptation.
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Affiliation(s)
- Sandra Garrett
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Stem Cell Institute, UConn Health, Farmington, CT 06030, USA
| | - Masami Shiimori
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Elizabeth A Watts
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Landon Clark
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, UConn Stem Cell Institute, UConn Health, Farmington, CT 06030, USA
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.,Department of Microbiology, University of Georgia, Athens, GA 30602, USA.,Department of Genetics, University of Georgia, Athens, GA 30602, USA
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33
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Nimkar S, Anand B. Cas3/I-C mediated target DNA recognition and cleavage during CRISPR interference are independent of the composition and architecture of Cascade surveillance complex. Nucleic Acids Res 2020; 48:2486-2501. [PMID: 31980818 PMCID: PMC7049708 DOI: 10.1093/nar/gkz1218] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 12/17/2019] [Accepted: 01/22/2020] [Indexed: 12/26/2022] Open
Abstract
In type I CRISPR-Cas system, Cas3—a nuclease cum helicase—in cooperation with Cascade surveillance complex cleaves the target DNA. Unlike the Cascade/I-E, which is composed of five subunits, the Cascade/I-C is made of only three subunits lacking the CRISPR RNA processing enzyme Cas6, whose role is assumed by Cas5. How these differences in the composition and organization of Cascade subunits in type I-C influence the Cas3/I-C binding and its target cleavage mechanism is poorly understood. Here, we show that Cas3/I-C is intrinsically a single-strand specific promiscuous nuclease. Apart from the helicase domain, a constellation of highly conserved residues—which are unique to type I-C—located in the uncharacterized C-terminal domain appears to influence the nuclease activity. Recruited by Cascade/I-C, the HD nuclease of Cas3/I-C nicks the single-stranded region of the non-target strand and positions the helicase motor. Powered by ATP, the helicase motor reels in the target DNA, until it encounters the roadblock en route, which stimulates the HD nuclease. Remarkably, we show that Cas3/I-C supplants Cas3/I-E for CRISPR interference in type I-E in vivo, suggesting that the target cleavage mechanism is evolutionarily conserved between type I-C and type I-E despite the architectural difference exhibited by Cascade/I-C and Cascade/I-E.
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Affiliation(s)
- Siddharth Nimkar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - B Anand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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34
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Real-time observation of CRISPR spacer acquisition by Cas1-Cas2 integrase. Nat Struct Mol Biol 2020; 27:489-499. [PMID: 32367067 PMCID: PMC7241818 DOI: 10.1038/s41594-020-0415-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 03/16/2020] [Indexed: 01/13/2023]
Abstract
Cas1 integrase associates with Cas2 to insert short DNA fragments into a CRISPR array, establishing nucleic acid memory in prokaryotes. Here we applied single-molecule FRET methods to the Enterococcus faecalis (Efa) Cas1–Cas2 system to establish a kinetic framework describing target-searching, integration, and post-synapsis events. EfaCas1–Cas2 on its own is not able to find the CRISPR repeat in the CRISPR array; it only does so after prespacer loading. The leader sequence adjacent to the repeat further stabilizes EfaCas1–Cas2 contacts, enabling leader-side integration and subsequent spacer-side integration. The resulting post-synaptic complex has a surprisingly short mean lifetime. Remarkably, transcription efficiently resolves the postsynaptic complex and we predict that this is a conserved mechanism that ensures efficient and directional spacer integration in many CRISPR systems. Overall, our study provides a complete model of spacer acquisition, which can be harnessed for DNA-based information storage and cell lineage tracing technologies.
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35
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Dhingra Y, Sashital DG. Updating the CRISPR Catalogue. CRISPR J 2020; 3:78-80. [PMID: 32315221 DOI: 10.1089/crispr.2020.29088.ydh] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa, USA
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36
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Weissman JL, Stoltzfus A, Westra ER, Johnson PLF. Avoidance of Self during CRISPR Immunization. Trends Microbiol 2020; 28:543-553. [PMID: 32544441 DOI: 10.1016/j.tim.2020.02.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 02/05/2020] [Accepted: 02/25/2020] [Indexed: 02/07/2023]
Abstract
The battle between microbes and their viruses is ancient and ongoing. Clustered regularly interspaced short palindromic repeat (CRISPR) immunity, the first and, to date, only form of adaptive immunity found in prokaryotes, represents a flexible mechanism to recall past infections while also adapting to a changing pathogenic environment. Critical to the role of CRISPR as an adaptive immune mechanism is its capacity for self versus non-self recognition when acquiring novel immune memories. Yet, CRISPR systems vary widely in both how and to what degree they can distinguish foreign from self-derived genetic material. We document known and hypothesized mechanisms that bias the acquisition of immune memory towards non-self targets. We demonstrate that diversity is the rule, with many widespread but no universal mechanisms for self versus non-self recognition.
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Affiliation(s)
- Jake L Weissman
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Arlin Stoltzfus
- Office of Data and Informatics, Material Measurement Laboratory, NIST, Gaithersburg, MD 20899, USA; Institute for Bioscience and Biotechnology Research, 9600 Gudelsky Drive, Rockville, MD 20850, USA
| | - Edze R Westra
- Environment and Sustainability Institute, Centre for Ecology and Conservation, University of Exeter, Biosciences, Penryn, Cornwall, UK
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37
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McKitterick AC, LeGault KN, Angermeyer A, Alam M, Seed KD. Competition between mobile genetic elements drives optimization of a phage-encoded CRISPR-Cas system: insights from a natural arms race. Philos Trans R Soc Lond B Biol Sci 2020; 374:20180089. [PMID: 30905288 PMCID: PMC6452262 DOI: 10.1098/rstb.2018.0089] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
CRISPR-Cas systems function as adaptive immune systems by acquiring nucleotide sequences called spacers that mediate sequence-specific defence against competitors. Uniquely, the phage ICP1 encodes a Type I-F CRISPR-Cas system that is deployed to target and overcome PLE, a mobile genetic element with anti-phage activity in Vibrio cholerae. Here, we exploit the arms race between ICP1 and PLE to examine spacer acquisition and interference under laboratory conditions to reconcile findings from wild populations. Natural ICP1 isolates encode multiple spacers directed against PLE, but we find that single spacers do not interfere equally with PLE mobilization. High-throughput sequencing to assay spacer acquisition reveals that ICP1 can also acquire spacers that target the V. cholerae chromosome. We find that targeting the V. cholerae chromosome proximal to PLE is sufficient to block PLE and is dependent on Cas2-3 helicase activity. We propose a model in which indirect chromosomal spacers are able to circumvent PLE by Cas2-3-mediated processive degradation of the V. cholerae chromosome before PLE mobilization. Generally, laboratory-acquired spacers are much more diverse than the subset of spacers maintained by ICP1 in nature, showing how evolutionary pressures can constrain CRISPR-Cas targeting in ways that are often not appreciated through in vitro analyses. This article is part of a discussion meeting issue 'The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems'.
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Affiliation(s)
- Amelia C McKitterick
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA
| | - Kristen N LeGault
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA
| | - Angus Angermeyer
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA
| | - Munirul Alam
- 2 International Centre for Diarrhoeal Disease Research , Dhaka , Bangladesh
| | - Kimberley D Seed
- 1 Department of Plant and Microbial Biology, University of California , 111 Koshland Hall, Berkeley, CA 94720 , USA.,3 Chan Zuckerberg Biohub , San Francisco, CA 94158 , USA
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38
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Selective loading and processing of prespacers for precise CRISPR adaptation. Nature 2020; 579:141-145. [PMID: 32076262 DOI: 10.1038/s41586-020-2018-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 12/19/2019] [Indexed: 01/08/2023]
Abstract
CRISPR-Cas immunity protects prokaryotes against invading genetic elements1. It uses the highly conserved Cas1-Cas2 complex to establish inheritable memory (spacers)2-5. How Cas1-Cas2 acquires spacers from foreign DNA fragments (prespacers) and integrates them into the CRISPR locus in the correct orientation is unclear6,7. Here, using the high spatiotemporal resolution of single-molecule fluorescence, we show that Cas1-Cas2 selects precursors of prespacers from DNA in various forms-including single-stranded DNA and partial duplexes-in a manner that depends on both the length of the DNA strand and the presence of a protospacer adjacent motif (PAM) sequence. We also identify DnaQ exonucleases as enzymes that process the Cas1-Cas2-loaded prespacer precursors into mature prespacers of a suitable size for integration. Cas1-Cas2 protects the PAM sequence from maturation, which results in the production of asymmetrically trimmed prespacers and the subsequent integration of spacers in the correct orientation. Our results demonstrate the kinetic coordination of prespacer precursor selection and PAM trimming, providing insight into the mechanisms that underlie the integration of functional spacers in the CRISPR loci.
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39
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Cas3 Protein-A Review of a Multi-Tasking Machine. Genes (Basel) 2020; 11:genes11020208. [PMID: 32085454 PMCID: PMC7074321 DOI: 10.3390/genes11020208] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 02/14/2020] [Accepted: 02/16/2020] [Indexed: 01/20/2023] Open
Abstract
Cas3 has essential functions in CRISPR immunity but its other activities and roles, in vitro and in cells, are less widely known. We offer a concise review of the latest understanding and questions arising from studies of Cas3 mechanism during CRISPR immunity, and highlight recent attempts at using Cas3 for genetic editing. We then spotlight involvement of Cas3 in other aspects of cell biology, for which understanding is lacking—these focus on CRISPR systems as regulators of cellular processes in addition to defense against mobile genetic elements.
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40
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Vink JNA, Martens KJA, Vlot M, McKenzie RE, Almendros C, Estrada Bonilla B, Brocken DJW, Hohlbein J, Brouns SJJ. Direct Visualization of Native CRISPR Target Search in Live Bacteria Reveals Cascade DNA Surveillance Mechanism. Mol Cell 2020; 77:39-50.e10. [PMID: 31735642 DOI: 10.1016/j.molcel.2019.10.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 07/31/2019] [Accepted: 10/11/2019] [Indexed: 11/24/2022]
Abstract
CRISPR-Cas systems encode RNA-guided surveillance complexes to find and cleave invading DNA elements. While it is thought that invaders are neutralized minutes after cell entry, the mechanism and kinetics of target search and its impact on CRISPR protection levels have remained unknown. Here, we visualize individual Cascade complexes in a native type I CRISPR-Cas system. We uncover an exponential relation between Cascade copy number and CRISPR interference levels, pointing to a time-driven arms race between invader replication and target search, in which 20 Cascade complexes provide 50% protection. Driven by PAM-interacting subunit Cas8e, Cascade spends half its search time rapidly probing DNA (∼30 ms) in the nucleoid. We further demonstrate that target DNA transcription and CRISPR arrays affect the integrity of Cascade and affect CRISPR interference. Our work establishes the mechanism of cellular DNA surveillance by Cascade that allows the timely detection of invading DNA in a crowded, DNA-packed environment.
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Affiliation(s)
- Jochem N A Vink
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Koen J A Martens
- Laboratory of Biophysics, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands; Laboratory of Bionanotechnology, Wageningen University & Research, Bornse Weilanden 9, 6708 WG Wageningen, the Netherlands
| | - Marnix Vlot
- Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Rebecca E McKenzie
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Cristóbal Almendros
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Boris Estrada Bonilla
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands
| | - Daan J W Brocken
- Leiden Institute of Chemistry, Gorlaeus Laboratories, Leiden University, Leiden, the Netherlands
| | - Johannes Hohlbein
- Laboratory of Biophysics, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands; Microspectroscopy Research Facility, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
| | - Stan J J Brouns
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, the Netherlands.
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41
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Morisaka H, Yoshimi K, Okuzaki Y, Gee P, Kunihiro Y, Sonpho E, Xu H, Sasakawa N, Naito Y, Nakada S, Yamamoto T, Sano S, Hotta A, Takeda J, Mashimo T. CRISPR-Cas3 induces broad and unidirectional genome editing in human cells. Nat Commun 2019; 10:5302. [PMID: 31811138 PMCID: PMC6897959 DOI: 10.1038/s41467-019-13226-x] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 10/29/2019] [Indexed: 12/21/2022] Open
Abstract
Although single-component Class 2 CRISPR systems, such as type II Cas9 or type V Cas12a (Cpf1), are widely used for genome editing in eukaryotic cells, the application of multi-component Class 1 CRISPR has been less developed. Here we demonstrate that type I-E CRISPR mediates distinct DNA cleavage activity in human cells. Notably, Cas3, which possesses helicase and nuclease activity, predominantly triggered several thousand base pair deletions upstream of the 5'-ARG protospacer adjacent motif (PAM), without prominent off-target activity. This Cas3-mediated directional and broad DNA degradation can be used to introduce functional gene knockouts and knock-ins. As an example of potential therapeutic applications, we show Cas3-mediated exon-skipping of the Duchenne muscular dystrophy (DMD) gene in patient-induced pluripotent stem cells (iPSCs). These findings broaden our understanding of the Class 1 CRISPR system, which may serve as a unique genome editing tool in eukaryotic cells distinct from the Class 2 CRISPR system.
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Affiliation(s)
- Hiroyuki Morisaka
- Department of Genome Biology, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
- Department of Dermatology, Kochi Medical School, Kochi University, Kochi, 783-8505, Japan
| | - Kazuto Yoshimi
- Genome Editing Research and Development Center, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
| | - Yuya Okuzaki
- Center for iPS Cell Research and Application (CiRA), Department of Clinical Application, Kyoto University, Kyoto, 606-8507, Japan
| | - Peter Gee
- Center for iPS Cell Research and Application (CiRA), Department of Clinical Application, Kyoto University, Kyoto, 606-8507, Japan
| | - Yayoi Kunihiro
- Genome Editing Research and Development Center, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
| | - Ekasit Sonpho
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan
- Department of Biology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Huaigeng Xu
- Center for iPS Cell Research and Application (CiRA), Department of Clinical Application, Kyoto University, Kyoto, 606-8507, Japan
| | - Noriko Sasakawa
- Center for iPS Cell Research and Application (CiRA), Department of Clinical Application, Kyoto University, Kyoto, 606-8507, Japan
| | - Yuki Naito
- Database Center for Life Science, Mishima, 411-8540, Japan
- National Institute of Genetics, Mishima, 411-8540, Japan
| | - Shinichiro Nakada
- Institute for Advanced Co-Creation Studies, Osaka University, Osaka, 565-0871, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan
| | - Shigetoshi Sano
- Department of Dermatology, Kochi Medical School, Kochi University, Kochi, 783-8505, Japan
| | - Akitsu Hotta
- Center for iPS Cell Research and Application (CiRA), Department of Clinical Application, Kyoto University, Kyoto, 606-8507, Japan.
| | - Junji Takeda
- Department of Genome Biology, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan.
- Research Institute for Microbial Diseases, Osaka University, Osaka, 565-0871, Japan.
| | - Tomoji Mashimo
- Genome Editing Research and Development Center, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan.
- Institute of Experimental Animal Sciences, Graduate School of Medicine, Osaka University, Osaka, 565-0871, Japan.
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan.
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42
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Kim JG, Garrett S, Wei Y, Graveley BR, Terns MP. CRISPR DNA elements controlling site-specific spacer integration and proper repeat length by a Type II CRISPR-Cas system. Nucleic Acids Res 2019; 47:8632-8648. [PMID: 31392984 PMCID: PMC6895254 DOI: 10.1093/nar/gkz677] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/19/2019] [Accepted: 07/30/2019] [Indexed: 12/26/2022] Open
Abstract
CRISPR–Cas systems provide heritable immunity against viruses by capturing short invader DNA sequences, termed spacers, and incorporating them into the CRISPR loci of the prokaryotic host genome. Here, we investigate DNA elements that control accurate spacer uptake in the type II-A CRISPR locus of Streptococcus thermophilus. We determined that purified Cas1 and Cas2 proteins catalyze spacer integration with high specificity for CRISPR repeat junctions. We show that 10 bp of the CRISPR leader sequence is critical for stimulating polarized integration preferentially at the repeat proximal to the leader. Spacer integration proceeds through a two-step transesterification reaction where the 3′ hydroxyl groups of the spacer target both repeat borders on opposite strands. The leader-proximal end of the repeat is preferentially targeted for the first site of integration through recognition of sequences spanning the leader-repeat junction. Subsequently, second-site integration at the leader-distal end of the repeat is specified by multiple determinants including a length-defining mechanism relying on a repeat element proximal to the second site of integration. Our results highlight the intrinsic ability of type II Cas1/Cas2 proteins to coordinate directional and site-specific spacer integration into the CRISPR locus to ensure precise duplication of the repeat required for CRISPR immunity.
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Affiliation(s)
- Jenny G Kim
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Sandra Garrett
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Yunzhou Wei
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, Institute for Systems Genomics, University of Connecticut Health Center, Farmington, CT 06030, USA
| | - Michael P Terns
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA 30602, USA.,Department of Microbiology, University of Georgia, Athens, GA 30602, USA.,Department of Genetics, University of Georgia, Athens, GA 30602, USA
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43
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Cameron P, Coons MM, Klompe SE, Lied AM, Smith SC, Vidal B, Donohoue PD, Rotstein T, Kohrs BW, Nyer DB, Kennedy R, Banh LM, Williams C, Toh MS, Irby MJ, Edwards LS, Lin CH, Owen ALG, Künne T, van der Oost J, Brouns SJJ, Slorach EM, Fuller CK, Gradia S, Kanner SB, May AP, Sternberg SH. Harnessing type I CRISPR-Cas systems for genome engineering in human cells. Nat Biotechnol 2019; 37:1471-1477. [PMID: 31740839 DOI: 10.1038/s41587-019-0310-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 10/06/2019] [Indexed: 12/26/2022]
Abstract
Type I CRISPR-Cas systems are the most abundant adaptive immune systems in bacteria and archaea1,2. Target interference relies on a multi-subunit, RNA-guided complex called Cascade3,4, which recruits a trans-acting helicase-nuclease, Cas3, for target degradation5-7. Type I systems have rarely been used for eukaryotic genome engineering applications owing to the relative difficulty of heterologous expression of the multicomponent Cascade complex. Here, we fuse Cascade to the dimerization-dependent, non-specific FokI nuclease domain8-11 and achieve RNA-guided gene editing in multiple human cell lines with high specificity and efficiencies of up to ~50%. FokI-Cascade can be reconstituted via an optimized two-component expression system encoding the CRISPR-associated (Cas) proteins on a single polycistronic vector and the guide RNA (gRNA) on a separate plasmid. Expression of the full Cascade-Cas3 complex in human cells resulted in targeted deletions of up to ~200 kb in length. Our work demonstrates that highly abundant, previously untapped type I CRISPR-Cas systems can be harnessed for genome engineering applications in eukaryotic cells.
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Affiliation(s)
| | | | - Sanne E Klompe
- Caribou Biosciences, Inc., Berkeley, CA, USA.,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
| | | | | | | | | | - Tomer Rotstein
- Caribou Biosciences, Inc., Berkeley, CA, USA.,Biomedical Engineering, Duke University, Durham, NC, USA
| | | | | | - Rachel Kennedy
- Caribou Biosciences, Inc., Berkeley, CA, USA.,Invitae Corporation, San Francisco, CA, USA
| | | | | | | | | | | | | | | | - Tim Künne
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Stan J J Brouns
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands.,Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
| | | | | | | | | | - Andrew P May
- Caribou Biosciences, Inc., Berkeley, CA, USA.,Sana Biotechnology, South San Francisco, CA, USA
| | - Samuel H Sternberg
- Caribou Biosciences, Inc., Berkeley, CA, USA. .,Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
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44
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Genome Maintenance Proteins Modulate Autoimmunity Mediated Primed Adaptation by the Escherichia coli Type I-E CRISPR-Cas System. Genes (Basel) 2019; 10:genes10110872. [PMID: 31683605 PMCID: PMC6896009 DOI: 10.3390/genes10110872] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 10/22/2019] [Accepted: 10/28/2019] [Indexed: 12/21/2022] Open
Abstract
Bacteria and archaea use CRISPR-Cas adaptive immunity systems to interfere with viruses, plasmids, and other mobile genetic elements. During the process of adaptation, CRISPR-Cas systems acquire immunity by incorporating short fragments of invaders’ genomes into CRISPR arrays. The acquisition of fragments of host genomes leads to autoimmunity and may drive chromosomal rearrangements, negative cell selection, and influence bacterial evolution. In this study, we investigated the role of proteins involved in genome stability maintenance in spacer acquisition by the Escherichia coli type I-E CRISPR-Cas system targeting its own genome. We show here, that the deletion of recJ decreases adaptation efficiency and affects accuracy of spacers incorporation into CRISPR array. Primed adaptation efficiency is also dramatically inhibited in double mutants lacking recB and sbcD but not in single mutants suggesting independent involvement and redundancy of RecBCD and SbcCD pathways in spacer acquisition. While the presence of at least one of two complexes is crucial for efficient primed adaptation, RecBCD and SbcCD affect the pattern of acquired spacers. Overall, our data suggest distinct roles of the RecBCD and SbcCD complexes and of RecJ in spacer precursor selection and insertion into CRISPR array and highlight the functional interplay between CRISPR-Cas systems and host genome maintenance mechanisms.
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45
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Detection of spacer precursors formed in vivo during primed CRISPR adaptation. Nat Commun 2019; 10:4603. [PMID: 31601800 PMCID: PMC6787059 DOI: 10.1038/s41467-019-12417-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 09/08/2019] [Indexed: 02/03/2023] Open
Abstract
Type I CRISPR-Cas loci provide prokaryotes with a nucleic-acid-based adaptive immunity against foreign DNA. Immunity involves adaptation, the integration of ~30-bp DNA fragments, termed prespacers, into the CRISPR array as spacers, and interference, the targeted degradation of DNA containing a protospacer. Interference-driven DNA degradation can be coupled with primed adaptation, in which spacers are acquired from DNA surrounding the targeted protospacer. Here we develop a method for strand-specific, high-throughput sequencing of DNA fragments, FragSeq, and apply this method to identify DNA fragments accumulated in Escherichia coli cells undergoing robust primed adaptation by a type I-E or type I-F CRISPR-Cas system. The detected fragments have sequences matching spacers acquired during primed adaptation and function as spacer precursors when introduced exogenously into cells by transformation. The identified prespacers contain a characteristic asymmetrical structure that we propose is a key determinant of integration into the CRISPR array in an orientation that confers immunity. Primed adaptation in the CRISPR-Cas system helps recognition of previously encountered sequence elements and promotes the formation of new memories. Here the authors characterized spacer precursors of type I-E and type I-F CRISPR-Cas system using in vivo models.
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46
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Nussenzweig PM, McGinn J, Marraffini LA. Cas9 Cleavage of Viral Genomes Primes the Acquisition of New Immunological Memories. Cell Host Microbe 2019; 26:515-526.e6. [PMID: 31585845 PMCID: PMC7558852 DOI: 10.1016/j.chom.2019.09.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 02/06/2023]
Abstract
Type II CRISPR-Cas systems defend prokaryotes from bacteriophage infection through the acquisition of short viral DNA sequences known as spacers, which are transcribed into short RNA guides to specify the targets of the Cas9 nuclease. To counter the potentially devastating propagation of escaper phages with mutations in the target sequences, the host population acquires many different spacers. Whether and how pre-existing spacers in type II systems affect the acquisition of new ones is unknown. Here, we demonstrate that previously acquired spacers promote additional spacer acquisition from the vicinity of the target DNA site cleaved by Cas9. Therefore, CRISPR immune cells acquire additional spacers at the same time as they destroy the infecting virus. This anticipates the rise of escapers or related viruses that could escape targeting by the first spacer acquired. Our results thus reveal Cas9's role in the generation of immunological memories.
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Affiliation(s)
- Philip M Nussenzweig
- Laboratory of Bacteriology, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Jon McGinn
- Laboratory of Bacteriology, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA
| | - Luciano A Marraffini
- Laboratory of Bacteriology, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, 1230 York Ave., New York, NY 10065, USA.
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47
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Filamentation initiated by Cas2 and its association with the acquisition process in cells. Int J Oral Sci 2019; 11:29. [PMID: 31578319 PMCID: PMC6802651 DOI: 10.1038/s41368-019-0063-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/18/2019] [Accepted: 07/07/2019] [Indexed: 12/15/2022] Open
Abstract
Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity. The process is critical for the ecology of the oral microflora and oral health. Although molecular mechanisms for spacer acquisition are known, it has never been established if this process is associated with the morphological changes of bacteria. In this study, we demonstrated a novel Cas2-induced filamentation phenotype in E. coli that was regulated by co-expression of the Cas1 protein. A 30 amino acid motif at the carboxyl terminus of Cas2 is necessary for this function. By imaging analysis, we provided evidence to argue that Cas-induced filamentation is a step coupled with new spacer acquisition during which filaments are characterised by polyploidy with asymmetric cell division. This work may open new opportunities to investigate the adaptive immune response and microbial balance for oral health.
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48
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Cui TJ, Joo C. Facilitated diffusion of Argonaute-mediated target search. RNA Biol 2019; 16:1093-1107. [PMID: 31068066 PMCID: PMC6693542 DOI: 10.1080/15476286.2019.1616353] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 10/26/2022] Open
Abstract
Argonaute (Ago) proteins are of key importance in many cellular processes. In eukaryotes, Ago can induce translational repression followed by deadenylation and degradation of mRNA molecules through base pairing of microRNAs (miRNAs) with a complementary target on a mRNA sequence. In bacteria, Ago eliminates foreign DNA through base pairing of siDNA (small interfering DNA) with a target on a DNA sequence. Effective targeting activities of Ago require fast recognition of the cognate target sequence among numerous off-target sites. Other target search proteins such as transcription factors (TFs) are known to rely on facilitated diffusion for this goal, but it is undetermined to what extent these small nucleic acid-guided proteins utilize this mechanism. Here, we review recent single-molecule studies on Ago target search. We discuss the consequences of the recent findings on the search mechanism. Furthermore, we discuss the open standing research questions that need to be addressed for a complete picture of facilitated target search by small nucleic acids.
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Affiliation(s)
- Tao Ju Cui
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
| | - Chirlmin Joo
- Kavli Institute of Nanoscience and Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
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49
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Plateau P, Moch C, Blanquet S. Spermidine strongly increases the fidelity of Escherichia coli CRISPR Cas1-Cas2 integrase. J Biol Chem 2019; 294:11311-11322. [PMID: 31171718 DOI: 10.1074/jbc.ra119.007619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/03/2019] [Indexed: 12/20/2022] Open
Abstract
Site-selective CRISPR array expansion at the origin of bacterial adaptive immunity relies on recognition of sequence-dependent DNA structures by the conserved Cas1-Cas2 integrase. Off-target integration of a new spacer sequence outside canonical CRISPR arrays has been described in vitro However, this nonspecific integration activity is rare in vivo Here, we designed gel assays to monitor fluorescently labeled protospacer insertion in a supercoiled 3-kb plasmid harboring a minimal CRISPR locus derived from the Escherichia coli type I-E system. This assay enabled us to distinguish and quantify target and off-target insertion events catalyzed by E. coli Cas1-Cas2 integrase. We show that addition of the ubiquitous polyamine spermidine or of another polyamine, spermine, significantly alters the ratio between target and off-target insertions. Notably, addition of 2 mm spermidine quenched the off-target spacer insertion rate by a factor of 20-fold, and, in the presence of integration host factor, spermidine also increased insertion at the CRISPR locus 1.5-fold. The observation made in our in vitro system that spermidine strongly decreases nonspecific activity of Cas1-Cas2 integrase outside the leader-proximal region of a CRISPR array suggests that this polyamine plays a potential role in the fidelity of the spacer integration also in vivo.
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Affiliation(s)
- Pierre Plateau
- BIOC, CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau, France
| | - Clara Moch
- BIOC, CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau, France
| | - Sylvain Blanquet
- BIOC, CNRS, Ecole polytechnique, IP Paris, F-91128 Palaiseau, France
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50
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Dolan AE, Hou Z, Xiao Y, Gramelspacher MJ, Heo J, Howden SE, Freddolino PL, Ke A, Zhang Y. Introducing a Spectrum of Long-Range Genomic Deletions in Human Embryonic Stem Cells Using Type I CRISPR-Cas. Mol Cell 2019; 74:936-950.e5. [PMID: 30975459 PMCID: PMC6555677 DOI: 10.1016/j.molcel.2019.03.014] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/04/2019] [Accepted: 03/13/2019] [Indexed: 01/08/2023]
Abstract
CRISPR-Cas systems enable microbial adaptive immunity and provide eukaryotic genome editing tools. These tools employ a single effector enzyme of type II or V CRISPR to generate RNA-guided, precise genome breaks. Here we demonstrate the feasibility of using type I CRISPR-Cas to effectively introduce a spectrum of long-range chromosomal deletions with a single RNA guide in human embryonic stem cells and HAP1 cells. Type I CRISPR systems rely on the multi-subunit ribonucleoprotein (RNP) complex Cascade to identify DNA targets and on the helicase-nuclease enzyme Cas3 to degrade DNA processively. With RNP delivery of T. fusca Cascade and Cas3, we obtained 13%-60% editing efficiency. Long-range PCR-based and high-throughput-sequencing-based lesion analyses reveal that a variety of deletions, ranging from a few hundred base pairs to 100 kilobases, are created upstream of the target site. These results highlight the potential utility of type I CRISPR-Cas for long-range genome manipulations and deletion screens in eukaryotes.
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Affiliation(s)
- Adam E Dolan
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA
| | - Zhonggang Hou
- Department of Biological Chemistry, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Yibei Xiao
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA; State Key Laboratory of Natural Medicines, Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China
| | - Max J Gramelspacher
- Department of Biological Chemistry, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Jaewon Heo
- Department of Biological Chemistry, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA
| | - Sara E Howden
- Murdoch Children's Research Institute, Flemington Rd., Parkville, VIC 3052, Australia; Department of Paediatrics, University of Melbourne, Parkville, VIC 3052, Australia
| | - Peter L Freddolino
- Department of Biological Chemistry, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA; Department of Computational Medicine and Bioinformatics, University of Michigan, 100 Washtenaw Avenue, Ann Arbor, MI 48109, USA
| | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, 253 Biotechnology Building, Ithaca, NY 14853, USA.
| | - Yan Zhang
- Department of Biological Chemistry, University of Michigan, 1150 W. Medical Center Drive, Ann Arbor, MI 48109, USA.
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