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Wang S, Zeng X, Jiang Y, Wang W, Bai L, Lu Y, Zhang L, Tan GY. Unleashing the potential: type I CRISPR-Cas systems in actinomycetes for genome editing. Nat Prod Rep 2024. [PMID: 38888887 DOI: 10.1039/d4np00010b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
Covering: up to the end of 2023Type I CRISPR-Cas systems are widely distributed, found in over 40% of bacteria and 80% of archaea. Among genome-sequenced actinomycetes (particularly Streptomyces spp.), 45.54% possess type I CRISPR-Cas systems. In comparison to widely used CRISPR systems like Cas9 or Cas12a, these endogenous CRISPR-Cas systems have significant advantages, including better compatibility, wide distribution, and ease of operation (since no exogenous Cas gene delivery is needed). Furthermore, type I CRISPR-Cas systems can simultaneously edit and regulate genes by adjusting the crRNA spacer length. Meanwhile, most actinomycetes are recalcitrant to genetic manipulation, hindering the discovery and engineering of natural products (NPs). The endogenous type I CRISPR-Cas systems in actinomycetes may offer a promising alternative to overcome these barriers. This review summarizes the challenges and recent advances in CRISPR-based genome engineering technologies for actinomycetes. It also presents and discusses how to establish and develop genome editing tools based on type I CRISPR-Cas systems in actinomycetes, with the aim of their future application in gene editing and the discovery of NPs in actinomycetes.
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Affiliation(s)
- Shuliu Wang
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Xiaoqian Zeng
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Yue Jiang
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Weishan Wang
- State Key Laboratory of Microbial Resources and CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences (CAS), Beijing 100101, China
| | - Linquan Bai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yinhua Lu
- College of Life Sciences, Shanghai Normal University, Shanghai 200234, China
| | - Lixin Zhang
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
| | - Gao-Yi Tan
- State Key Laboratory of Bioreactor Engineering (SKLBE), School of Biotechnology, East China University of Science and Technology (ECUST), Shanghai 200237, China.
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2
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Li M, Chen F, Yang Q, Tang Q, Xiao Z, Tong X, Zhang Y, Lei L, Li S. Biomaterial-Based CRISPR/Cas9 Delivery Systems for Tumor Treatment. Biomater Res 2024; 28:0023. [PMID: 38694229 PMCID: PMC11062511 DOI: 10.34133/bmr.0023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 03/25/2024] [Indexed: 05/04/2024] Open
Abstract
CRISPR/Cas9 gene editing technology is characterized by high specificity and efficiency, and has been applied to the treatment of human diseases, especially tumors involving multiple genetic modifications. However, the clinical application of CRISPR/Cas9 still faces some major challenges, the most urgent of which is the development of optimized delivery vectors. Biomaterials are currently the best choice for use in CRISPR/Cas9 delivery vectors owing to their tunability, biocompatibility, and efficiency. As research on biomaterial vectors continues to progress, hope for the application of the CRISPR/Cas9 system for clinical oncology therapy builds. In this review, we first detail the CRISPR/Cas9 system and its potential applications in tumor therapy. Then, we introduce the different delivery forms and compare the physical, viral, and non-viral vectors. In addition, we analyze the characteristics of different types of biomaterial vectors. We further review recent research progress in the use of biomaterials as vectors for CRISPR/Cas9 delivery to treat specific tumors. Finally, we summarize the shortcomings and prospects of biomaterial-based CRISPR/Cas9 delivery systems.
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Affiliation(s)
- Mengmeng Li
- Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
| | - Fenglei Chen
- College of Veterinary Medicine, Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses,
Yangzhou University, Yangzhou 225009, China
| | - Qian Yang
- Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
| | - Qinglai Tang
- Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
| | - Zian Xiao
- Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
| | - Xinying Tong
- Department of Hemodialysis, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
| | - Ying Zhang
- Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
| | - Lanjie Lei
- Institute of Translational Medicine,
Zhejiang Shuren University, Hangzhou 310015, Zhejiang, China
| | - Shisheng Li
- Department of Otorhinolaryngology Head and Neck Surgery, the Second Xiangya Hospital,
Central South University, Changsha 410011, Hunan, China
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3
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Zheng C, Liang H, Dai L, Yu J, Long C. Dissecting the CRISPR Cas1-Cas2 Protospacer Binding and Selection Mechanism by Using Molecular Dynamics Simulations. J Phys Chem B 2024; 128:3563-3574. [PMID: 38573978 DOI: 10.1021/acs.jpcb.3c07320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2024]
Abstract
Cas1 and Cas2 are highly conserved proteins among the clustered regularly interspaced short palindromic repeat Cas (CRISPR-Cas) systems and play a crucial role in protospacer selection and integration. According to the double-forked CRISPR Cas1-Cas2 complex, we conducted extensive all-atom molecular dynamics simulations to investigate the protospacer DNA binding and recognition. Our findings revealed that single-point amino acid mutations in Cas1 or in Cas2 had little impact on the binding of the protospacer, both in the binding and precatalytic states. In contrast, multiple-point amino acid mutations, particularly G74A, P80L, and V89A mutations on Cas2 and Cas2' proteins (m-multiple1 system), significantly affected the protospacer binding and selection. Notably, mutations on Cas2 and Cas2' led to an increased number of hydrogen bonds (#HBs) between Cas2&Cas2' and the dsDNA in the m-multiple1 system compared with the wild-type system. And the strong electrostatic interactions between Cas1-Cas2 and the protospacer DNA (psDNA) in the m-multiple1 system again suggested the increase in the binding affinity of protospacer acquisition. Specifically, mutations in Cas2 and Cas2' can remotely make the protospacer adjacent motif complementary (PAMc) sequences better in recognition by the two active sites, while multiple mutations K211E, P202Q, P212L, R138L, V134A, A286T, P282H, and P294H on Cas1a/Cas1b&Cas1a'/Cas1b' (m-multiple2 system) decrease the #HBs and the electrostatic interactions and make the PAMc worse in recognition compared with the wild-type system.
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Affiliation(s)
- Chuanbo Zheng
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Hongqiong Liang
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Liqiang Dai
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou 325001, China
| | - Jin Yu
- Department of Physics and Astronomy, Department of Chemistry, NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, California 92697, United States
| | - Chunhong Long
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
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4
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Mohr G, Yao J, Park SK, Markham L, Lambowitz AM. Mechanisms used for cDNA synthesis and site-specific integration of RNA into DNA genomes by a reverse transcriptase-Cas1 fusion protein. SCIENCE ADVANCES 2024; 10:eadk8791. [PMID: 38608016 PMCID: PMC11014452 DOI: 10.1126/sciadv.adk8791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 03/08/2024] [Indexed: 04/14/2024]
Abstract
Reverse transcriptase-Cas1 (RT-Cas1) fusion proteins found in some CRISPR systems enable spacer acquisition from both RNA and DNA, but the mechanism of RNA spacer acquisition has remained unclear. Here, we found that Marinomonas mediterranea RT-Cas1/Cas2 adds short 3'-DNA (dN) tails to RNA protospacers, enabling their direct integration into CRISPR arrays as 3'-dN-RNAs or 3'-dN-RNA/cDNA duplexes at rates comparable to similarly configured DNAs. Reverse transcription of RNA protospacers is initiated at 3' proximal sites by multiple mechanisms, including recently described de novo initiation, protein priming with any dNTP, and use of short exogenous or synthesized DNA oligomer primers, enabling synthesis of near full-length cDNAs of diverse RNAs without fixed sequence requirements. The integration of 3'-dN-RNAs or single-stranded DNAs (ssDNAs) is favored over duplexes at higher protospacer concentrations, potentially relevant to spacer acquisition from abundant pathogen RNAs or ssDNA fragments generated by phage defense nucleases. Our findings reveal mechanisms for site-specifically integrating RNA into DNA genomes with potential biotechnological applications.
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Affiliation(s)
- Georg Mohr
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA
| | - Jun Yao
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA
| | | | - Laura Markham
- Departments of Molecular Biosciences and Oncology, University of Texas at Austin, Austin, TX 78712, USA
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5
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Su X, Jin X, Wang Z, Duan S. Unraveling Exogenous DNA Processing in Cas4-Lacking Crispr Systems: A Novel Bypass Pathway Explored. Adv Biol (Weinh) 2024; 8:e2300454. [PMID: 38072634 DOI: 10.1002/adbi.202300454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 11/09/2023] [Indexed: 03/16/2024]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems are widely distributed adaptive immune systems found in prokaryotes. The process involves three main stages: adaptation, expression, and interference. While the adaptation stage has been extensively studied, there is still an incomplete understanding of the mechanisms underlying the capture, trimming, and integration of exogenous DNA. For instance, Cas4, a CRISPR-Cas protein with endonuclease activity, is responsible for selecting and processing protospacer adjacent motif (PAM) sequences. However, some CRISPR isoforms lack Cas4 activity, relying on other enzymes for adaptive immunity. Recently, Wang et al. presented a novel model of exogenous DNA processing in a type I-E CRISPR system lacking Cas4 in a Nature article. This model integrates protospacer processing into CRISPR arrays through fine-tuned synthases formed by DnaQ-like exonuclease (DEDDh) and Cas1-Cas2 complexes. Their study introduces a novel model, shedding new light on the evolution of CRISPR adaptive immunity. This perspective comprehensively examines the fundamental process of CRISPR adaptive immunity, detailing both the classical pathway mediated by Cas4 and the alternative pathway mediated by DEDDh. Furthermore, a thorough evaluation of Wang et al.'s work is conducted, highlighting its strengths, weaknesses, and existing research challenges.
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Affiliation(s)
- Xinming Su
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
- Department of Clinical Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
| | - Xiaoyu Jin
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
- Department of Clinical Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
| | - Zehua Wang
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
- Department of Clinical Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
| | - Shiwei Duan
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
- Department of Clinical Medicine, Hangzhou City University, Hangzhou, Zhejiang, 310000, China
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6
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Oh GS, An S, Kim S. Harnessing CRISPR-Cas adaptation for RNA recording and beyond. BMB Rep 2024; 57:40-49. [PMID: 38053290 PMCID: PMC10828431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/04/2023] [Accepted: 04/04/2023] [Indexed: 12/07/2023] Open
Abstract
Prokaryotes encode clustered regularly interspaced short palindromic repeat (CRISPR) arrays and CRISPR-associated (Cas) genes as an adaptive immune machinery. CRISPR-Cas systems effectively protect hosts from the invasion of foreign enemies, such as bacteriophages and plasmids. During a process called 'adaptation', non-self-nucleic acid fragments are acquired as spacers between repeats in the host CRISPR array, to establish immunological memory. The highly conserved Cas1-Cas2 complexes function as molecular recorders to integrate spacers in a time course manner, which can subsequently be expressed as crRNAs complexed with Cas effector proteins for the RNAguided interference pathways. In some of the RNA-targeting type III systems, Cas1 proteins are fused with reverse transcriptase (RT), indicating that RT-Cas1-Cas2 complexes can acquire RNA transcripts for spacer acquisition. In this review, we summarize current studies that focus on the molecular structure and function of the RT-fused Cas1-Cas2 integrase, and its potential applications as a directional RNA-recording tool in cells. Furthermore, we highlight outstanding questions for RT-Cas1-Cas2 studies and future directions for RNA-recording CRISPR technologies. [BMB Reports 2024; 57(1): 40-49].
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Affiliation(s)
- Gyeong-Seok Oh
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
| | - Seongjin An
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
- Department of Life Sciences, School of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea
| | - Sungchul Kim
- Center for RNA Research, Institute for Basic Science, Seoul 08826, Korea
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7
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Panahi B, Dehganzad B, Nami Y. CRISPR-Cas systems feature and targeting phages diversity in Lacticaseibacillus rhamnosus strains. Front Microbiol 2023; 14:1281307. [PMID: 38125580 PMCID: PMC10731254 DOI: 10.3389/fmicb.2023.1281307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/20/2023] [Indexed: 12/23/2023] Open
Abstract
One of the most important adaptive immune systems in bacteria against phages is clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (CAS) genes. In this investigation, an approach based on genome mining was employed to characterize the CRISPR-Cas systems of Lacticaseibacillus rhamnosus strains. The analysis involved retrieving complete genome sequences of L. rhamnosus strains, and assessing the diversity, prevalence, and evolution of their CRISPR-Cas systems. Following this, an analysis of homology in spacer sequences from identified CRISPR arrays was carried out to investigate and characterize the range of target phages. The findings revealed that 106 strains possessed valid CRISPR-Cas structures (comprising CRISPR loci and Cas genes), constituting 45% of the examined L. rhamnosus strains. The diversity observed in the CRISPR-Cas systems indicated that all identified systems belonged to subtype II-A. Analyzing the homology of spacer sequences with phage and prophage genomes discovered that strains possessing only CRISPR-Cas subtype II targeted a broader spectrum of foreign phages. In summary, this study suggests that while there is not significant diversity among the CRISPR-Cas systems identified in L. rhamnosus strains, there exists notable variation in subtype II-A systems between L. rhamnosus and other lactobacilli. The diverse nature of these CRISPR-Cas systems underscores their natural activity and importance in adaptive immunity.
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Affiliation(s)
- Bahman Panahi
- Department of Genomics, Branch for Northwest and West Region, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
| | - Behnaz Dehganzad
- Department of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Yousef Nami
- Department of Food Biotechnology, Branch for Northwest and West Region, Agricultural Biotechnology Research Institute of Iran (ABRII), Agricultural Research, Education and Extension Organization (AREEO), Tabriz, Iran
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8
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Mohr G, Yao J, Park SK, Markham LM, Lambowitz AM. Mechanisms used for cDNA synthesis and site-specific integration of RNA into DNA genomes by a reverse transcriptase-Cas1 fusion protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555893. [PMID: 37693417 PMCID: PMC10491204 DOI: 10.1101/2023.09.01.555893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Reverse transcriptase-Cas1 (RT-Cas1) fusion proteins found in some CRISPR systems enable spacer acquisition from both RNA and DNA, but the mechanism of RNA spacer acquisition has remained unclear. Here, we found Marinomonas mediterranea RT-Cas1/Cas2 adds short 3'-DNA (dN) tails to RNA protospacers enabling their direct integration into CRISPR arrays as 3'-dN-RNA/cDNA duplexes or 3'-dN-RNAs at rates comparable to similarly configured DNAs. Reverse transcription of RNA protospacers occurs by multiple mechanisms, including recently described de novo initiation, protein priming with any dNTP, and use of short exogenous or synthesized DNA oligomer primers, enabling synthesis of cDNAs from diverse RNAs without fixed sequence requirements. The integration of 3'-dN-RNAs or single-stranded (ss) DNAs is favored over duplexes at higher protospacer concentrations, potentially relevant to spacer acquisition from abundant pathogen RNAs or ssDNA fragments generated by phage-defense nucleases. Our findings reveal novel mechanisms for site-specifically integrating RNA into DNA genomes with potential biotechnological applications.
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Affiliation(s)
- Georg Mohr
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
| | - Jun Yao
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
| | | | - Laura M. Markham
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
| | - Alan M. Lambowitz
- Departments of Molecular Biosciences and Oncology University of Texas at Austin Austin TX, 78712
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9
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Huang S, Dai R, Zhang Z, Zhang H, Zhang M, Li Z, Zhao K, Xiong W, Cheng S, Wang B, Wan Y. CRISPR/Cas-Based Techniques for Live-Cell Imaging and Bioanalysis. Int J Mol Sci 2023; 24:13447. [PMID: 37686249 PMCID: PMC10487896 DOI: 10.3390/ijms241713447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/09/2023] [Accepted: 08/24/2023] [Indexed: 09/10/2023] Open
Abstract
CRISPR/Cas systems have found widespread applications in gene editing due to their high accuracy, high programmability, ease of use, and affordability. Benefiting from the cleavage properties (trans- or cis-) of Cas enzymes, the scope of CRISPR/Cas systems has expanded beyond gene editing and they have been utilized in various fields, particularly in live-cell imaging and bioanalysis. In this review, we summarize some fundamental working mechanisms and concepts of the CRISPR/Cas systems, describe the recent advances and design principles of CRISPR/Cas mediated techniques employed in live-cell imaging and bioanalysis, highlight the main applications in the imaging and biosensing of a wide range of molecular targets, and discuss the challenges and prospects of CRISPR/Cas systems in live-cell imaging and biosensing. By illustrating the imaging and bio-sensing processes, we hope this review will guide the best use of the CRISPR/Cas in imaging and quantifying biological and clinical elements and inspire new ideas for better tool design in live-cell imaging and bioanalysis.
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Affiliation(s)
- Shuo Huang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Rui Dai
- Institute of Oceanography, Hainan University, Haikou 570228, China;
| | - Zhiqi Zhang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Han Zhang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Meng Zhang
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Zhangjun Li
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Kangrui Zhao
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Wenjun Xiong
- College of Life Sciences, Hainan University, Haikou 570228, China; (S.H.); (Z.Z.); (H.Z.); (M.Z.); (Z.L.); (K.Z.); (W.X.)
| | - Siyu Cheng
- College of Art and Design, Hainan University, Haikou 570228, China;
| | - Buhua Wang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
| | - Yi Wan
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou 570228, China
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10
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Wang JY, Tuck OT, Skopintsev P, Soczek KM, Li G, Al-Shayeb B, Zhou J, Doudna JA. Genome expansion by a CRISPR trimmer-integrase. Nature 2023:10.1038/s41586-023-06178-2. [PMID: 37316664 DOI: 10.1038/s41586-023-06178-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 05/08/2023] [Indexed: 06/16/2023]
Abstract
CRISPR-Cas adaptive immune systems capture DNA fragments from invading mobile genetic elements and integrate them into the host genome to provide a template for RNA-guided immunity1. CRISPR systems maintain genome integrity and avoid autoimmunity by distinguishing between self and non-self, a process for which the CRISPR/Cas1-Cas2 integrase is necessary but not sufficient2-5. In some microorganisms, the Cas4 endonuclease assists CRISPR adaptation6,7, but many CRISPR-Cas systems lack Cas48. Here we show here that an elegant alternative pathway in a type I-E system uses an internal DnaQ-like exonuclease (DEDDh) to select and process DNA for integration using the protospacer adjacent motif (PAM). The natural Cas1-Cas2/exonuclease fusion (trimmer-integrase) catalyses coordinated DNA capture, trimming and integration. Five cryo-electron microscopy structures of the CRISPR trimmer-integrase, visualized both before and during DNA integration, show how asymmetric processing generates size-defined, PAM-containing substrates. Before genome integration, the PAM sequence is released by Cas1 and cleaved by the exonuclease, marking inserted DNA as self and preventing aberrant CRISPR targeting of the host. Together, these data support a model in which CRISPR systems lacking Cas4 use fused or recruited9,10 exonucleases for faithful acquisition of new CRISPR immune sequences.
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Affiliation(s)
- Joy Y Wang
- Department of Chemistry, University of California, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | - Owen T Tuck
- Department of Chemistry, University of California, Berkeley, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | - Petr Skopintsev
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, USA
| | - Katarzyna M Soczek
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, USA
| | - Gary Li
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
- Department of Bioengineering, University of California, Berkeley, CA, USA
| | - Basem Al-Shayeb
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | - Julia Zhou
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Jennifer A Doudna
- Department of Chemistry, University of California, Berkeley, CA, USA.
- Innovative Genomics Institute, University of California, Berkeley, CA, USA.
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, USA.
- Department of Bioengineering, University of California, Berkeley, CA, USA.
- Howard Hughes Medical Institute, University of California, Berkeley, CA, USA.
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
- Gladstone Institutes, University of California, San Francisco, CA, USA.
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11
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Dhingra Y, Sashital DG. Cas4/1 dual nuclease activities enable prespacer maturation and directional integration in a type I-G CRISPR-Cas system. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543779. [PMID: 37333257 PMCID: PMC10274657 DOI: 10.1101/2023.06.05.543779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
CRISPR-Cas adaptive immune systems uptake short 'spacer' sequences from foreign DNA and incorporate them into the host genome to serve as templates for crRNAs that guide interference against future infections. Adaptation in CRISPR systems is mediated by Cas1-Cas2 complexes that catalyze integration of prespacer substrates into the CRISPR array. Many DNA targeting systems also require Cas4 endonucleases for functional spacer acquisition. Cas4 selects prespacers containing a protospacer adjacent motif (PAM) and removes the PAM prior to integration, both of which are required to ensure host immunization. Cas1 has also been shown to function as a nuclease in some systems, but a role for this nuclease activity in adaptation has not been demonstrated. We identified a type I-G Cas4/1 fusion with a nucleolytically active Cas1 domain that can directly participate in prespacer processing. The Cas1 domain is both an integrase and a sequence-independent nuclease that cleaves the non-PAM end of a prespacer, generating optimal overhang lengths that enable integration at the leader side. The Cas4 domain sequence-specifically cleaves the PAM end of the prespacer, ensuring integration of the PAM end at the spacer side. The two domains have varying metal ion requirements. While Cas4 activity is Mn 2+ dependent, Cas1 preferentially uses Mg 2+ over Mn 2+ . The dual nuclease activity of Cas4/1 eliminates the need for additional factors in prespacer processing, making the adaptation module self-reliant for prespacer maturation and directional integration.
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Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
| | - Dipali G. Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
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12
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McBride TM, Cameron SC, Fineran PC, Fagerlund RD. The biology and type I/III hybrid nature of type I-D CRISPR-Cas systems. Biochem J 2023; 480:471-488. [PMID: 37052300 DOI: 10.1042/bcj20220073] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2022] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 04/14/2023]
Abstract
Prokaryotes have adaptive defence mechanisms that protect them from mobile genetic elements and viral infection. One defence mechanism is called CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated proteins). There are six different types of CRISPR-Cas systems and multiple subtypes that vary in composition and mode of action. Type I and III CRISPR-Cas systems utilise multi-protein complexes, which differ in structure, nucleic acid binding and cleaving preference. The type I-D system is a chimera of type I and III systems. Recently, there has been a burst of research on the type I-D CRISPR-Cas system. Here, we review the mechanism, evolution and biotechnological applications of the type I-D CRISPR-Cas system.
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Affiliation(s)
- Tess M McBride
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Shaharn C Cameron
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Robert D Fagerlund
- Department of Microbiology and Immunology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, PO Box 56, Dunedin 9054, New Zealand
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13
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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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14
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Rasmussen TS, Koefoed AK, Deng L, Muhammed MK, Rousseau GM, Kot W, Sprotte S, Neve H, Franz CMAP, Hansen AK, Vogensen FK, Moineau S, Nielsen DS. CRISPR-Cas provides limited phage immunity to a prevalent gut bacterium in gnotobiotic mice. THE ISME JOURNAL 2023; 17:432-442. [PMID: 36631688 PMCID: PMC9938214 DOI: 10.1038/s41396-023-01358-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 12/22/2022] [Accepted: 01/06/2023] [Indexed: 01/13/2023]
Abstract
Many bacteria and archaea harbor the adaptive CRISPR-Cas system, which stores small nucleotide fragments from previous invasions of nucleic acids via viruses or plasmids. This molecular archive blocks further invaders carrying identical or similar nucleotide sequences. However, few of these systems have been confirmed experimentally to be active in gut bacteria. Here, we demonstrate experimentally that the type I-C CRISPR-Cas system of the prevalent gut bacterium Eggerthella lenta can specifically target and cleave foreign DNA in vitro by using a plasmid transformation assay. We also show that the CRISPR-Cas system acquires new immunities (spacers) from the genome of a virulent E. lenta phage using traditional phage assays in vitro but also in vivo using gnotobiotic (GB) mice. Both high phage titer and an increased number of spacer acquisition events were observed when E. lenta was exposed to a low multiplicity of infection in vitro, and three phage genes were found to contain protospacer hotspots. Fewer new spacer acquisitions were detected in vivo than in vitro. Longitudinal analysis of phage-bacteria interactions showed sustained coexistence in the gut of GB mice, with phage abundance being approximately one log higher than the bacteria. Our findings show that while the type I-C CRISPR-Cas system is active in vitro and in vivo, a highly virulent phage in vitro was still able to co-exist with its bacterial host in vivo. Taken altogether, our results suggest that the CRISPR-Cas defense system of E. lenta provides only partial immunity in the gut.
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Affiliation(s)
- Torben Sølbeck Rasmussen
- Section of Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, 1958, Frederiksberg, Denmark.
| | - Anna Kirstine Koefoed
- Section of Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Ling Deng
- Section of Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Musemma K Muhammed
- Section of Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Geneviève M Rousseau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de 1enie, Université Laval, Québec, QC, G1V 0A6, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Witold Kot
- Section of Microbial Ecology and Biotechnology, Department of Plant and Environmental Sciences, University of Copenhagen, 1871, Frederiksberg, Denmark
| | - Sabrina Sprotte
- Department of Microbiology and Biotechnology, Max Rubner-Institut, 24103, Kiel, Germany
| | - Horst Neve
- Department of Microbiology and Biotechnology, Max Rubner-Institut, 24103, Kiel, Germany
| | - Charles M A P Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, 24103, Kiel, Germany
| | - Axel Kornerup Hansen
- Section of Experimental Animal Models, Department of Veterinary and Animal Sciences, University of Copenhagen, 1871, Frederiksberg, Denmark
| | - Finn Kvist Vogensen
- Section of Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, 1958, Frederiksberg, Denmark
| | - Sylvain Moineau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de 1enie, Université Laval, Québec, QC, G1V 0A6, Canada
- Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, Québec, QC, G1V 0A6, Canada
- Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, Québec, QC, G1V 0A6, Canada
| | - Dennis Sandris Nielsen
- Section of Microbiology and Fermentation, Department of Food Science, Faculty of Science, University of Copenhagen, 1958, Frederiksberg, Denmark.
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15
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Flusche T, Rajan R. Molecular Details of DNA Integration by CRISPR-Associated Proteins During Adaptation in Bacteria and Archaea. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1414:27-43. [PMID: 35852729 DOI: 10.1007/5584_2022_730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system in bacteria and archaea, where immunological memory is retained in the CRISPR locus as short pieces of the intruding nucleic acid, termed spacers. The adaptation to new infections occurs through the integration of a new spacer into the CRISPR array. For immune protection, spacers are transcribed into CRISPR RNAs (crRNA) that are used to guide the effector nuclease of the system in sequence-dependent target cleavage. Spacers originate as a prespacer from either DNA or RNA depending on the CRISPR-Cas system being observed, and the nearly universal Cas proteins, Cas1 and Cas2, insert the prespacer into the CRISPR locus during adaptation in all systems that contain them. The mechanism of site-specific prespacer integration varies across CRISPR classes and types, and distinct differences can even be found within the same subtype. In this review, the current knowledge on the mechanisms of prespacer integration in type II-A CRISPR-Cas systems will be described. Comparisons of the currently characterized type II-A systems show that distinct mechanisms exist within different members of this subtype and are correlated to sequence-specific interactions of Cas proteins and the DNA elements present in the CRISPR array. These observations indicate that nature has fine-tuned the mechanistic details while performing the basic step of DNA integration by Cas proteins, which offers unique advantages to develop Cas1-Cas2-based biotechnology.
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Affiliation(s)
- Tamara Flusche
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, OK, USA.
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16
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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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17
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Dhingra Y, Suresh SK, Juneja P, Sashital DG. PAM binding ensures orientational integration during Cas4-Cas1-Cas2-mediated CRISPR adaptation. Mol Cell 2022; 82:4353-4367.e6. [PMID: 36272411 PMCID: PMC9675710 DOI: 10.1016/j.molcel.2022.09.030] [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: 06/03/2022] [Revised: 08/10/2022] [Accepted: 09/28/2022] [Indexed: 11/06/2022]
Abstract
Adaptation in CRISPR-Cas systems immunizes bacteria and archaea against mobile genetic elements. In many DNA-targeting systems, the Cas4-Cas1-Cas2 complex is required for selection and processing of DNA segments containing PAM sequences prior to integration of these "prespacer" substrates as spacers in the CRISPR array. We determined cryo-EM structures of the Cas4-Cas1-Cas2 adaptation complex from the type I-C system that encodes standalone Cas1 and Cas4 proteins. The structures reveal how Cas4 specifically reads out bases within the PAM sequence and how interactions with both Cas1 and Cas2 activate Cas4 endonuclease activity. The Cas4-PAM interaction ensures tight binding between the adaptation complex and the prespacer, significantly enhancing integration of the non-PAM end into the CRISPR array and ensuring correct spacer orientation. Corroborated with our biochemical results, Cas4-Cas1-Cas2 structures with substrates representing various stages of CRISPR adaptation reveal a temporally resolved mechanism for maturation and integration of functional spacers into the CRISPR array.
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Affiliation(s)
- Yukti Dhingra
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
| | - Shravanti K Suresh
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA
| | - Puneet Juneja
- Cryo-EM Facility, Office of Biotechnology, Iowa State University, Ames, IA, USA
| | - Dipali G Sashital
- Roy J. Carver Department of Biochemistry, Biophysics, & Molecular Biology, Iowa State University, Ames, IA, USA.
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18
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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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19
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Anand V, Prabhakaran HS, Gogoi P, Kanaujia SP, Kumar M. Structural and functional characterization of Cas2 of CRISPR-Cas subtype I-C lacking the CRISPR component. Front Mol Biosci 2022; 9:988569. [PMID: 36172044 PMCID: PMC9510766 DOI: 10.3389/fmolb.2022.988569] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/08/2022] [Indexed: 11/29/2022] Open
Abstract
The genome of pathogenic Leptospira interrogans serovars (Copenhageni and Lai) are predicted to have CRISPR-Cas of subtypes I-B and I-C. Cas2, one of the core Cas proteins, has a crucial role in adaptive defense against foreign nucleic acids. However, subtype I-C lacks the CRISPR element at its loci essential for RNA-mediated adaptive immunity against foreign nucleic acids. The reason for sustaining the expense of cas genes are unknown in the absence of a CRISPR array. Thus, Cas2C was chosen as a representative Cas protein from two well-studied serovars of Leptospira to address whether it is functional. In this study, the recombinant Cas2C of Leptospira serovars Copenhageni (rLinCas2C, 12 kDa) and Lai (rLinCas2C_Lai, 8.6 kDa) were overexpressed and purified. Due to natural frameshift mutation in the cas2c gene of serovar Lai, rLinCas2C_Lai was overexpressed and purified as a partially translated protein. Nevertheless, the recombinant Cas2C from each serovar exhibited metal-dependent DNase and metal-independent RNase activities. The crystal structure of rLinCas2C obtained at the resolution of 2.60 Å revealed the protein is in apostate conformation and contains N- (1–71 amino acids) and C-terminal (72–90 amino acids) regions, with the former possessing a ferredoxin fold. Substitution of the conserved residues (Tyr7, Asp8, Arg33, and Phe39) with alanine and deletion of Loop L2 resulted in compromised DNase activity. On the other hand, a moderate reduction in RNase activity was evident only in selective rLinCas2C mutants. Overall, in the absence of an array, the observed catalytic activity of Cas2C may be required for biological processes distinct from the CRISPR-Cas-associated function.
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Affiliation(s)
| | | | | | | | - Manish Kumar
- *Correspondence: Shankar Prasad Kanaujia, ; Manish Kumar,
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20
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Zhang X, An X. Adaptation by Type III CRISPR-Cas Systems: Breakthrough Findings and Open Questions. Front Microbiol 2022; 13:876174. [PMID: 35495695 PMCID: PMC9048733 DOI: 10.3389/fmicb.2022.876174] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/03/2022] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems acquire heritable defense memory against invading nucleic acids through adaptation. Type III CRISPR-Cas systems have unique and intriguing features of defense and are important in method development for Genetics research. We started to understand the common and unique properties of type III CRISPR-Cas adaptation in recent years. This review summarizes our knowledge regarding CRISPR-Cas adaptation with the emphasis on type III systems and discusses open questions for type III adaptation studies.
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Affiliation(s)
- Xinfu Zhang
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, United States
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center of Tree breeding and Ecological Remediation, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- *Correspondence: Xinfu Zhang,
| | - Xinmin An
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, National Engineering Research Center of Tree breeding and Ecological Remediation, College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
- Xinmin An,
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21
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Bharathkumar N, Sunil A, Meera P, Aksah S, Kannan M, Saravanan KM, Anand T. CRISPR/Cas-Based Modifications for Therapeutic Applications: A Review. Mol Biotechnol 2022; 64:355-372. [PMID: 34741732 PMCID: PMC8571677 DOI: 10.1007/s12033-021-00422-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/28/2021] [Indexed: 12/11/2022]
Abstract
The CRISPR-Cas genome editing system is an intrinsic property of a bacteria-based immune system. This employs a guide RNA to detect and cleave the PAM-associated target DNA or RNA in subsequent infections, by the invasion of a similar bacteriophage. The discovery of Cas systems has paved the way to overcome the limitations of existing genome editing tools. In this review, we focus on Cas proteins that are available for gene modifications among which Cas9, Cas12a, and Cas13 have been widely used in the areas of medicine, research, and diagnostics. Since CRISPR has been already proven for its potential research applications, the next milestone for CRISPR will be proving its efficacy and safety. In this connection, we systematically review recent advances in exploring multiple variants of Cas proteins and their modifications for therapeutic applications.
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Affiliation(s)
| | - Abraham Sunil
- Department of Animal Behavior and Physiology, Madurai Kamaraj University, Madurai, Tamil Nadu India
| | - Prabhakar Meera
- B Aatral Biosciences Private Limited, Bangalore, Karnataka India
| | - Sam Aksah
- B Aatral Biosciences Private Limited, Bangalore, Karnataka India
| | - Muthu Kannan
- B Aatral Biosciences Private Limited, Bangalore, Karnataka India
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22
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Wentz TG, Tremblay BJM, Bradshaw M, Doxey AC, Sharma SK, Sauer JD, Pellett S. Endogenous CRISPR-Cas Systems in Group I Clostridium botulinum and Clostridium sporogenes Do Not Directly Target the Botulinum Neurotoxin Gene Cluster. Front Microbiol 2022; 12:787726. [PMID: 35222299 PMCID: PMC8865420 DOI: 10.3389/fmicb.2021.787726] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 12/27/2021] [Indexed: 12/28/2022] Open
Abstract
Most strains of proteolytic group I Clostridium botulinum (G1 C. botulinum) and some strains of Clostridium sporogenes possess genes encoding botulinum neurotoxin (BoNT), a potent neuroparalytic agent. Within G1 C. botulinum, conserved bont gene clusters of three major toxin serotypes (bont/A/B/F) can be found on conjugative plasmids and/or within chromosomal pathogenicity islands. CRISPR-Cas systems enable site-specific targeting of previously encountered mobile genetic elements (MGE) such as plasmids and bacteriophage through the creation of a spacer library complementary to protospacers within the MGEs. To examine whether endogenous CRISPR-Cas systems restrict the transfer of bont gene clusters across strains we conducted a bioinformatic analysis profiling endogenous CRISPR-Cas systems from 241 G1 C. botulinum and C. sporogenes strains. Approximately 6,200 CRISPR spacers were identified across the strains and Type I-B, III-A/B/D cas genes and CRISPR array features were identified in 83% of the strains. Mapping the predicted spacers against the masked strain and RefSeq plasmid dataset identified 56,000 spacer-protospacer matches. While spacers mapped heavily to targets within bont(+) plasmids, no protospacers were identified within the bont gene clusters. These results indicate the toxin is not a direct target of CRISPR-Cas but the plasmids predominantly responsible for its mobilization are. Finally, while the presence of a CRISPR-Cas system did not reliably indicate the presence or absence of a bont gene cluster, comparative genomics across strains indicates they often occupy the same hypervariable loci common to both species, potentially suggesting similar mechanisms are involved in the acquisition and curation of both genomic features.
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Affiliation(s)
- Travis G. Wentz
- Microbiology Doctoral Training Program, University of Wisconsin–Madison, Madison, WI, United States,Division of Microbiology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States,Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, United States
| | | | - Marite Bradshaw
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, United States
| | - Andrew C. Doxey
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Shashi K. Sharma
- Division of Microbiology, Center for Food Safety and Applied Nutrition, Food and Drug Administration, College Park, MD, United States
| | - John-Demian Sauer
- Department of Medical Microbiology and Immunology, University of Wisconsin–Madison, Madison, WI, United States
| | - Sabine Pellett
- Department of Bacteriology, University of Wisconsin–Madison, Madison, WI, United States,*Correspondence: Sabine Pellett,
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23
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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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24
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Pan S, Zhang H. Discovery in CRISPR-Cas9 system. ZHONG NAN DA XUE XUE BAO. YI XUE BAN = JOURNAL OF CENTRAL SOUTH UNIVERSITY. MEDICAL SCIENCES 2021; 46:1392-1402. [PMID: 35232910 PMCID: PMC10930580 DOI: 10.11817/j.issn.1672-7347.2021.210169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Indexed: 06/14/2023]
Abstract
The 2020 Nobel Prize in Chemistry was awarded to the American scientist Jennifer A. Doudna and the French scientist Emmanuelle Charpentier, in recognition of their discovery in one of the greatest weapons in genetic technology: CRISPR-Cas9 gene scissors. The CRISPR-Cas system is a bacterial defense immune system against exogenous genetic material. Because the system can specifically recognize and cut DNA, this technology is widely used for precise editing of animal, plant, and microbial DNA. The discovery of CRISPR-Cas9 gene scissors enables the tedious and complicated cell gene editing work to be completed in a few weeks or even less, which has promoted the development of gene editing technology in various fields and brought revolutionary influence to the field of life sciences. At the same time, CRISPR gene editing technology has become one of the new therapies for tumors because of its large number of targets and relatively simple operation, and it also makes gene therapy possible. Although the technology still needs to solve technical problems such as off-target and promoter inefficiency, the CRISPR-Cas system will show its unique advantages in more fields with the continuous development of life science and basic medicine.
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Affiliation(s)
- Shaowei Pan
- Department of Pathophysiology, School of Basic Medical Science, Central South University, Changsha 410013, China.
| | - Huali Zhang
- Department of Pathophysiology, School of Basic Medical Science, Central South University, Changsha 410013, China.
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25
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Walker HE, Rizzo M, Fras Z, Jug B, Banach M, Penson PE. CRISPR Gene Editing in Lipid Disorders and Atherosclerosis: Mechanisms and Opportunities. Metabolites 2021; 11:857. [PMID: 34940615 PMCID: PMC8707018 DOI: 10.3390/metabo11120857] [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] [Received: 10/18/2021] [Revised: 11/25/2021] [Accepted: 12/04/2021] [Indexed: 12/24/2022] Open
Abstract
Elevated circulating concentrations of low-density lipoprotein cholesterol (LDL-C) have been conclusively demonstrated in epidemiological and intervention studies to be causally associated with the development of atherosclerotic cardiovascular disease. Enormous advances in LDL-C reduction have been achieved through the use of statins, and in recent years, through drugs targeting proprotein convertase subtilisin/kexin type 9 (PCSK9), a key regulator of the hepatic LDL-receptor. Existing approaches to PCSK9 targeting have used monoclonal antibodies or RNA interference. Although these approaches do not require daily dosing, as statins do, repeated subcutaneous injections are nevertheless necessary to maintain effectiveness over time. Recent experimental studies suggest that clustered regularly interspaced short palindromic repeats (CRISPR) gene-editing targeted at PCSK9 may represent a promising tool to achieve the elusive goal of a 'fire and forget' lifelong approach to LDL-C reduction. This paper will provide an overview of CRISPR technology, with a particular focus on recent studies with relevance to its potential use in atherosclerotic cardiovascular disease.
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Affiliation(s)
- Harry E. Walker
- School of Biological Sciences, Highfield Campus, University of Southampton, Southampton SO17 1BJ, UK;
| | - Manfredi Rizzo
- Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (Promise), University of Palermo, 90133 Palermo, Italy;
| | - Zlatko Fras
- Centre for Preventive Cardiology, Division of Medicine, University Medical Centre Ljubljana, SI-1525 Ljubljana, Slovenia;
- Medical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia
| | - Borut Jug
- Department of Vascular Diseases, University Medical Centre Ljubljana, SI-1525 Ljubljana, Slovenia;
| | - Maciej Banach
- Department of Preventive Cardiology and Lipidology, Medical University of Lodz, 93338 Lodz, Poland;
- Cardiovascular Research Centre, University of Zielona Gora, 65046 Zielona Gora, Poland
| | - Peter E. Penson
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Liverpool L3 3AF, UK
- Liverpool Centre for Cardiovascular Science, Liverpool L7 8TX, UK
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26
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Kumar A, Satpati P. Divalent-Metal-Ion Selectivity of the CRISPR-Cas System-Associated Cas1 Protein: Insights from Classical Molecular Dynamics Simulations and Electronic Structure Calculations. J Phys Chem B 2021; 125:11943-11954. [PMID: 34694813 DOI: 10.1021/acs.jpcb.1c07744] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
CRISPR-associated protein 1 (Cas1) is a universally conserved essential metalloenzyme of the clustered regularly interspaced short palindromic repeat (CRISPR) immune system of prokaryotes (bacteria, archaea) that can cut and integrate a part of viral DNA to its host genome with the help of other proteins. The integrated DNA acts as a memory of viral infection, which can be transcribed to RNA and stop future infection by recognition (based on the RNA/DNA complementarity principle) followed by protein-mediated degradation of the viral DNA. It has been proposed that the presence of a single manganese (Mn2+) ion in a conserved divalent-metal-ion binding pocket (key residues: E190, H254, D265, D268) of Cas1 is crucial for its function. Cas1-mediated DNA degradation was proposed to be hindered by metal substitution, metal chelation, or mutation of the binding pocket residues. Cas1 is active toward dsDNA degradation with both Mn2+ and Mg2+. X-ray structures of Cas1 revealed an intricate atomic interaction network of the divalent-metal-ion binding pocket and opened up the possibility of modeling related metal ions (viz., Mg2+, Ca2+) in the binding pocket of wild-type (WT) and mutated Cas1 proteins for computational analysis, which includes (1) quantitative estimation of the energetics of the divalent-metal-ion preference and (2) exploring the structural and dynamical aspects of the protein in response to divalent-metal-ion substitution or amino acid mutation. Using the X-ray structure of the Cas1 protein from Pseudomonas aeruginosa as a template (PDB 3GOD), we performed (∼2.23 μs) classical molecular dynamics (MD) simulations to compare structural and dynamical differences between Mg2+- and Ca2+-bound binding pockets of wild-type (WT) and mutant (E190A, H254A, D265A, D268A) Cas1. Furthermore, reduced binding pocket models were generated from X-ray and molecular dynamics (MD) trajectories, and the resulting structures were subjected to quantum chemical calculations. Results suggest that Cas1 prefers Mg2+ binding relative to Ca2+ and the preference is the strongest for WT and the weakest for the D268A mutant. Quantum chemical calculations indicate that Mn2+ is the most preferred relative to both Mg2+ and Ca2+ in the wild-type and mutant Cas1. Substitution of Mg2+ by Ca2+ does not alter the interaction network between Cas1 and the divalent metal ion but increases the wetness of the binding pocket by introducing a single water molecule in the first coordination shell of the latter. The strength of metal-ion preference (Mg2+ versus Ca2+) seems to be dependent on the solvent accessibility of the divalent-metal-ion binding pocket, strongest for wild-type Cas1 (in which the metal-ion binding pocket is dry, which includes two water molecules) and the weakest for the D268A mutant (in which the metal-ion binding pocket is wet, which includes four water molecules).
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Affiliation(s)
- Abhishek Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Priyadarshi Satpati
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
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27
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Guzmán NM, Esquerra-Ruvira B, Mojica FJM. Digging into the lesser-known aspects of CRISPR biology. Int Microbiol 2021; 24:473-498. [PMID: 34487299 PMCID: PMC8616872 DOI: 10.1007/s10123-021-00208-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 12/26/2022]
Abstract
A long time has passed since regularly interspaced DNA repeats were discovered in prokaryotes. Today, those enigmatic repetitive elements termed clustered regularly interspaced short palindromic repeats (CRISPR) are acknowledged as an emblematic part of multicomponent CRISPR-Cas (CRISPR associated) systems. These systems are involved in a variety of roles in bacteria and archaea, notably, that of conferring protection against transmissible genetic elements through an adaptive immune-like response. This review summarises the present knowledge on the diversity, molecular mechanisms and biology of CRISPR-Cas. We pay special attention to the most recent findings related to the determinants and consequences of CRISPR-Cas activity. Research on the basic features of these systems illustrates how instrumental the study of prokaryotes is for understanding biology in general, ultimately providing valuable tools for diverse fields and fuelling research beyond the mainstream.
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Affiliation(s)
- Noemí M Guzmán
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Belén Esquerra-Ruvira
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain
| | - Francisco J M Mojica
- Dpto. Fisiología, Genética y Microbiología, Universidad de Alicante, Alicante, Spain.
- Instituto Multidisciplinar para el Estudio del Medio, Universidad de Alicante, Alicante, Spain.
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28
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Mechanism for Cas4-assisted directional spacer acquisition in CRISPR-Cas. Nature 2021; 598:515-520. [PMID: 34588691 PMCID: PMC9164213 DOI: 10.1038/s41586-021-03951-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 08/25/2021] [Indexed: 02/08/2023]
Abstract
Prokaryotes adapt to challenges from mobile genetic elements by integrating spacers derived from foreign DNA in the CRISPR array1. Spacer insertion is carried out by the Cas1-Cas2 integrase complex2-4. A substantial fraction of CRISPR-Cas systems use a Fe-S cluster containing Cas4 nuclease to ensure that spacers are acquired from DNA flanked by a protospacer adjacent motif (PAM)5,6 and inserted into the CRISPR array unidirectionally, so that the transcribed CRISPR RNA can guide target searching in a PAM-dependent manner. Here we provide a high-resolution mechanistic explanation for the Cas4-assisted PAM selection, spacer biogenesis and directional integration by type I-G CRISPR in Geobacter sulfurreducens, in which Cas4 is naturally fused with Cas1, forming Cas4/Cas1. During biogenesis, only DNA duplexes possessing a PAM-embedded 3'-overhang trigger Cas4/Cas1-Cas2 assembly. During this process, the PAM overhang is specifically recognized and sequestered, but is not cleaved by Cas4. This 'molecular constipation' prevents the PAM-side prespacer from participating in integration. Lacking such sequestration, the non-PAM overhang is trimmed by host nucleases and integrated to the leader-side CRISPR repeat. Half-integration subsequently triggers PAM cleavage and Cas4 dissociation, allowing spacer-side integration. Overall, the intricate molecular interaction between Cas4 and Cas1-Cas2 selects PAM-containing prespacers for integration and couples the timing of PAM processing with the stepwise integration to establish directionality.
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29
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Vink JNA, Baijens JHL, Brouns SJJ. PAM-repeat associations and spacer selection preferences in single and co-occurring CRISPR-Cas systems. Genome Biol 2021; 22:281. [PMID: 34593010 PMCID: PMC8482600 DOI: 10.1186/s13059-021-02495-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Accepted: 09/09/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND The adaptive CRISPR-Cas immune system stores sequences from past invaders as spacers in CRISPR arrays and thereby provides direct evidence that links invaders to hosts. Mapping CRISPR spacers has revealed many aspects of CRISPR-Cas biology, including target requirements such as the protospacer adjacent motif (PAM). However, studies have so far been limited by a low number of mapped spacers in the database. RESULTS By using vast metagenomic sequence databases, we map approximately one-third of more than 200,000 unique CRISPR spacers from a variety of microbes and derive a catalog of more than two hundred unique PAM sequences associated with specific CRISPR-Cas subtypes. These PAMs are further used to correctly assign the orientation of CRISPR arrays, revealing conserved patterns between the last nucleotides of the CRISPR repeat and PAM. We could also deduce CRISPR-Cas subtype-specific preferences for targeting either template or coding strand of open reading frames. While some DNA-targeting systems (type I-E and type II systems) prefer the template strand and avoid mRNA, other DNA- and RNA-targeting systems (types I-A and I-B and type III systems) prefer the coding strand and mRNA. In addition, we find large-scale evidence that both CRISPR-Cas adaptation machinery and CRISPR arrays are shared between different CRISPR-Cas systems. This could lead to simultaneous DNA and RNA targeting of invaders, which may be effective at combating mobile genetic invaders. CONCLUSIONS This study has broad implications for our understanding of how CRISPR-Cas systems work in a wide range of organisms for which only the genome sequence is known.
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Affiliation(s)
- Jochem N A Vink
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Jan H L Baijens
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
- Kavli Institute of Nanoscience, Delft, The Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands.
- Kavli Institute of Nanoscience, Delft, The Netherlands.
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30
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Wang X, Yuan Q, Zhang W, Ji S, Lv Y, Ren K, Lu M, Xiao Y. Sequence specific integration by the family 1 casposase from Candidatus Nitrosopumilus koreensis AR1. Nucleic Acids Res 2021; 49:9938-9952. [PMID: 34428286 PMCID: PMC8464041 DOI: 10.1093/nar/gkab725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 11/13/2022] Open
Abstract
Casposase, a homolog of Cas1 integrase, is encoded by a superfamily of mobile genetic elements known as casposons. While family 2 casposase has been well documented in both function and structure, little is known about the other three casposase families. Here, we studied the family 1 casposase lacking the helix-turn-helix (HTH) domain from Candidatus Nitrosopumilus koreensis AR1 (Ca. N. koreensis). The determinants for integration by Ca. N. koreensis casposase were extensively investigated, and it was found that a 13-bp target site duplication (TSD) sequence, a minimal 3-bp leader and three different nucleotides of the TSD sequences are indispensable for target specific integration. Significantly, the casposase can site-specifically integrate a broad range of terminal inverted repeat (TIR)-derived oligonucleotides ranging from 7-nt to ∼4000-bp, and various oligonucleotides lacking the 5′-TTCTA-3′ motif at the 3′ end of TIR sequence can be integrated efficiently. Furthermore, similar to some Cas1 homologs, the casposase utilizes a 5′-ATAA-3′ motif in the TSD as a molecular ruler to dictate nucleophilic attack at 9-bp downstream of the end of the ruler during the spacer-side integration. By characterizing the family 1 Ca. N. koreensis casposase, we have extended our understanding on mechanistic similarities and evolutionary connections between casposons and the adaptation elements of CRISPR-Cas immunity.
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Affiliation(s)
- Xiaoke Wang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
| | - Qinling Yuan
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
| | - Wenxuan Zhang
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
| | - Suyu Ji
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
| | - Yang Lv
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
| | - Kejing Ren
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
| | - Meiling Lu
- Department of Biochemistry, School of Life Science and Technology, China Pharmaceutical University, Nanjing210009, China
| | - Yibei Xiao
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing210009, China.,Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing210009, China
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31
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Li Y, Qiao D, Zhang Y, Hao W, Xi Y, Deng X, Ge X, Xu M. MapZ deficiency leads to defects in the envelope structure and changes stress tolerance of Streptococcus mutans. Mol Oral Microbiol 2021; 36:295-307. [PMID: 34463029 DOI: 10.1111/omi.12352] [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: 06/18/2021] [Revised: 07/20/2021] [Accepted: 07/28/2021] [Indexed: 11/26/2022]
Abstract
Cell division is a central process in bacteria and a prerequisite for pathogenicity. Several proteins are involved in this process to ensure the accurate localization and proper function of the division machinery. In Streptococcus mutans, MapZ marks the division sites and position of the Z-ring to regulate cell division; however, whether MapZ deficiency can impair the cariogenic virulence of S. mutans remains unclear. Here, using a phenotypic assay and RNA-seq, we investigated the role of MapZ in cell envelope maintenance, biofilm formation, and stress tolerance in S. mutans. The results show that MapZ is important for normal cell shape and envelope structure, and its deletion causes abnormal septum structure and a thin cell wall. Subsequently, we found that the absence of MapZ leads to a greater level of cell death within 12 h biofilms, but it does not seem to affect biofilm architecture and accumulation. mapZ deletion also results in a decreased acid and osmotic stress tolerance. Furthermore, RNA-seq data reveal that MapZ deficiency causes changes in the expression levels of genes involved in transport systems, sugar metabolism, nature competence, and bacteriocin synthesis. Interestingly, we found that mapZ mutation renders S. mutans more sensitive to chlorhexidine. Taken together, our study suggests that MapZ plays a role in maintaining cell envelope structure and stress tolerance in S. mutans, showing a potential application as a drug target for caries prevention.
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Affiliation(s)
- Yongliang Li
- Department of Geriatric Dentistry, Peking University Hospital of Stomatology, Beijing, P. R. China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, P. R. China
| | - Dan Qiao
- Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, P. R. China
| | - Yifei Zhang
- National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, P. R. China.,Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, P. R. China
| | - Weifeng Hao
- National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, P. R. China
| | - Yue Xi
- National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, P. R. China
| | - Xuliang Deng
- Department of Geriatric Dentistry, Peking University Hospital of Stomatology, Beijing, P. R. China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, P. R. China
| | - Xuejun Ge
- Shanxi Medical University School and Hospital of Stomatology, Taiyuan, Shanxi, P. R. China
| | - Mingming Xu
- Department of Geriatric Dentistry, Peking University Hospital of Stomatology, Beijing, P. R. China.,National Engineering Laboratory for Digital and Material Technology of Stomatology, NMPA Key Laboratory for Dental Materials, Beijing Laboratory of Biomedical Materials, Peking University Hospital of Stomatology, Beijing, P. R. China
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32
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Maikova A, Boudry P, Shiriaeva A, Vasileva A, Boutserin A, Medvedeva S, Semenova E, Severinov K, Soutourina O. Protospacer-Adjacent Motif Specificity during Clostridioides difficile Type I-B CRISPR-Cas Interference and Adaptation. mBio 2021; 12:e0213621. [PMID: 34425703 PMCID: PMC8406132 DOI: 10.1128/mbio.02136-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 07/26/2021] [Indexed: 12/26/2022] Open
Abstract
CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems provide prokaryotes with efficient protection against foreign nucleic acid invaders. We have recently demonstrated the defensive interference function of a CRISPR-Cas system from Clostridioides (Clostridium) difficile, a major human enteropathogen, and showed that it could be harnessed for efficient genome editing in this bacterium. However, molecular details are still missing on CRISPR-Cas function for adaptation and sequence requirements for both interference and new spacer acquisition in this pathogen. Despite accumulating knowledge on the individual CRISPR-Cas systems in various prokaryotes, no data are available on the adaptation process in bacterial type I-B CRISPR-Cas systems. Here, we report the first experimental evidence that the C. difficile type I-B CRISPR-Cas system acquires new spacers upon overexpression of its adaptation module. The majority of new spacers are derived from a plasmid expressing Cas proteins required for adaptation or from regions of the C. difficile genome where generation of free DNA termini is expected. Results from protospacer-adjacent motif (PAM) library experiments and plasmid conjugation efficiency assays indicate that C. difficile CRISPR-Cas requires the YCN consensus PAM for efficient interference. We revealed a functional link between the adaptation and interference machineries, since newly adapted spacers are derived from sequences associated with a CCN PAM, which fits the interference consensus. The definition of functional PAMs and establishment of relative activity levels of each of the multiple C. difficile CRISPR arrays in present study are necessary for further CRISPR-based biotechnological and medical applications involving this organism. IMPORTANCE CRISPR-Cas systems provide prokaryotes with adaptive immunity for defense against foreign nucleic acid invaders, such as viruses or phages and plasmids. The CRISPR-Cas systems are highly diverse, and detailed studies of individual CRISPR-Cas subtypes are important for our understanding of various aspects of microbial adaptation strategies and for the potential applications. The significance of our work is in providing the first experimental evidence for type I-B CRISPR-Cas system adaptation in the emerging human enteropathogen Clostridioides difficile. This bacterium needs to survive in phage-rich gut communities, and its active CRISPR-Cas system might provide efficient antiphage defense by acquiring new spacers that constitute memory for further invader elimination. Our study also reveals a functional link between the adaptation and interference CRISPR machineries. The definition of all possible functional trinucleotide motifs upstream protospacers within foreign nucleic acid sequences is important for CRISPR-based genome editing in this pathogen and for developing new drugs against C. difficile infections.
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Affiliation(s)
- Anna Maikova
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Pierre Boudry
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Anna Shiriaeva
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg, Russia
| | - Aleksandra Vasileva
- Institute of Gene Biology, Centre for Precision Genome Editing and Genetic Technologies for Biomedicine, Russian Academy of Sciences, Moscow, Russia
| | - Anaïs Boutserin
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Sofia Medvedeva
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - Ekaterina Semenova
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
| | - Konstantin Severinov
- Center of Life Sciences, Skolkovo Institute of Science and Technology, Moscow, Russia
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, New Jersey, USA
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Olga Soutourina
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
- Institut Universitaire de France (IUF), Paris, France
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33
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Kieper SN, Almendros C, Haagsma AC, Barendregt A, Heck AJR, Brouns SJJ. Cas4-Cas1 Is a Protospacer Adjacent Motif-Processing Factor Mediating Half-Site Spacer Integration During CRISPR Adaptation. CRISPR J 2021; 4:536-548. [PMID: 34406043 DOI: 10.1089/crispr.2021.0011] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The immunization of bacteria and archaea against invading viruses via CRISPR adaptation is critically reliant on the efficient capture, accurate processing, and integration of CRISPR spacers into the host genome. The adaptation proteins Cas1 and Cas2 are sufficient for successful spacer acquisition in some CRISPR-Cas systems. However, many CRISPR-Cas systems additionally require the Cas4 protein for efficient adaptation. Cas4 has been implied in the selection and processing of spacer precursors, but the detailed mechanistic understanding of how Cas4 contributes to CRISPR adaptation is lacking. Here, we biochemically reconstitute the CRISPR-Cas type I-D adaptation system and show two functionally distinct adaptation complexes: Cas4-Cas1 and Cas1-Cas2. The Cas4-Cas1 complex recognizes and cleaves protospacer adjacent motif (PAM) sequences in 3' overhangs in a sequence-specific manner, while the Cas1-Cas2 complex defines the cleavage of non-PAM sites via host-factor nucleases. Both sub-complexes are capable of mediating half-site integration, facilitating the integration of processed spacers in the correct interference-proficient orientation. We provide a model in which an asymmetric adaptation complex differentially acts on PAM- and non-PAM-containing overhangs, providing cues for the correct orientation of spacer integration.
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Affiliation(s)
- Sebastian N Kieper
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
| | - Cristóbal Almendros
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
| | - Anna C Haagsma
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
| | - Arjan Barendregt
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands; and Utrecht, Netherlands.,Netherlands Proteomics Center, Utrecht, Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research, Utrecht Institute of Pharmaceutical Sciences, Utrecht University, Utrecht, Netherlands; and Utrecht, Netherlands.,Netherlands Proteomics Center, Utrecht, Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands.,Kavli Institute of Nanoscience, Delft University of Technology, Delft, Netherlands; Utrecht, Netherlands
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34
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Long C, Dai L, E C, Da LT, Yu J. Allosteric regulation in CRISPR/Cas1-Cas2 protospacer acquisition mediated by DNA and Cas2. Biophys J 2021; 120:3126-3137. [PMID: 34197800 PMCID: PMC8390960 DOI: 10.1016/j.bpj.2021.06.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 05/10/2021] [Accepted: 06/04/2021] [Indexed: 11/19/2022] Open
Abstract
Cas1 and Cas2 are highly conserved proteins across clustered-regularly-interspaced-short-palindromic-repeat-Cas systems and play a significant role in protospacer acquisition. Based on crystal structure of twofold symmetric Cas1-Cas2 in complex with dual-forked protospacer DNA (psDNA), we conducted all-atom molecular dynamics simulations to study the psDNA binding, recognition, and response to cleavage on the protospacer-adjacent-motif complementary sequence, or PAMc, of Cas1-Cas2. In the simulation, we noticed that two active sites of Cas1 and Cas1’ bind asymmetrically to two identical PAMc on the psDNA captured from the crystal structure. For the modified psDNA containing only one PAMc, as that to be recognized by Cas1-Cas2 in general, our simulations show that the non-PAMc association site of Cas1-Cas2 remains destabilized until after the stably bound PAMc being cleaved at the corresponding association site. Thus, long-range correlation appears to exist upon the PAMc cleavage between the two active sites (∼10 nm apart) on Cas1-Cas2, which can be allosterically mediated by psDNA and Cas2 and Cas2’ in bridging. To substantiate such findings, we conducted repeated runs and further simulated Cas1-Cas2 in complex with synthesized psDNA sequences psL and psH, which have been measured with low and high frequency in acquisition, respectively. Notably, such intersite correlation becomes even more pronounced for the Cas1-Cas2 in complex with psH but remains low for the Cas1-Cas2 in complex with psL. Hence, our studies demonstrate that PAMc recognition and cleavage at one active site of Cas1-Cas2 may allosterically regulate non-PAMc association or even cleavage at the other site, and such regulation can be mediated by noncatalytic Cas2 and DNA protospacer to possibly support the ensued psDNA acquisition.
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Affiliation(s)
- Chunhong Long
- School of Science, Chongqing University of Posts and Telecommunications, Chongqing, China
| | - Liqiang Dai
- Shenzhen JL Computational Science and Applied Research Institute, Shenzhen, China; Beijing Computational Science Research Center, Beijing, China
| | - Chao E
- Beijing Computational Science Research Center, Beijing, China
| | - Lin-Tai Da
- Shanghai Center for Systems Biomedicine, Shanghai JiaoTong University, Shanghai, China
| | - Jin Yu
- Departments of Physics and Astronomy and Chemistry, NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, California.
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35
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Pezoulas VC, Papaloukas C, Veyssiere M, Goules A, Tzioufas AG, Soumelis V, Fotiadis DI. A computational workflow for the detection of candidate diagnostic biomarkers of Kawasaki disease using time-series gene expression data. Comput Struct Biotechnol J 2021; 19:3058-3068. [PMID: 34136104 PMCID: PMC8178098 DOI: 10.1016/j.csbj.2021.05.036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 05/17/2021] [Accepted: 05/20/2021] [Indexed: 12/15/2022] Open
Abstract
Unlike autoimmune diseases, there is no known constitutive and disease-defining biomarker for systemic autoinflammatory diseases (SAIDs). Kawasaki disease (KD) is one of the "undiagnosed" types of SAIDs whose pathogenic mechanism and gene mutation still remain unknown. To address this issue, we have developed a sequential computational workflow which clusters KD patients with similar gene expression profiles across the three different KD phases (Acute, Subacute and Convalescent) and utilizes the resulting clustermap to detect prominent genes that can be used as diagnostic biomarkers for KD. Self-Organizing Maps (SOMs) were employed to cluster patients with similar gene expressions across the three phases through inter-phase and intra-phase clustering. Then, false discovery rate (FDR)-based feature selection was applied to detect genes that significantly deviate across the per-phase clusters. Our results revealed five genes as candidate biomarkers for KD diagnosis, namely, the HLA-DQB1, HLA-DRA, ZBTB48, TNFRSF13C, and CASD1. To our knowledge, these five genes are reported for the first time in the literature. The impact of the discovered genes for KD diagnosis against the known ones was demonstrated by training boosting ensembles (AdaBoost and XGBoost) for KD classification on common platform and cross-platform datasets. The classifiers which were trained on the proposed genes from the common platform data yielded an average increase by 4.40% in accuracy, 5.52% in sensitivity, and 3.57% in specificity than the known genes in the Acute and Subacute phases, followed by a notable increase by 2.30% in accuracy, 2.20% in sensitivity, and 4.70% in specificity in the cross-platform analysis.
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Affiliation(s)
- Vasileios C. Pezoulas
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina GR45110, Greece
| | - Costas Papaloukas
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina GR45110, Greece
- Department of Biological Applications and Technology, University of Ioannina, Ioannina GR45100, Greece
| | - Maëva Veyssiere
- INSERM U976, Human Immunology, Physiopathology and Immunotherapy, Paris, France
| | - Andreas Goules
- Department of Pathophysiology, School of Medicine, University of Athens, Athens GR15772, Greece
| | - Athanasios G. Tzioufas
- Department of Pathophysiology, School of Medicine, University of Athens, Athens GR15772, Greece
| | - Vassili Soumelis
- INSERM U976, Human Immunology, Physiopathology and Immunotherapy, Paris, France
- Hôpital Saint Louis, Saint Louis Research Institute, Paris, France
| | - Dimitrios I. Fotiadis
- Unit of Medical Technology and Intelligent Information Systems, Department of Materials Science and Engineering, University of Ioannina, Ioannina GR45110, Greece
- Department of Biomedical Research, FORTH (Foundation for Research & Technology)-IMBB (Institute of Molecular Biology and Biotechnology), Ioannina GR45110, Greece
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36
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Jakhanwal S, Cress BF, Maguin P, Lobba MJ, Marraffini LA, Doudna JA. A CRISPR-Cas9-integrase complex generates precise DNA fragments for genome integration. Nucleic Acids Res 2021; 49:3546-3556. [PMID: 33693715 PMCID: PMC8034620 DOI: 10.1093/nar/gkab123] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 02/04/2021] [Accepted: 02/26/2021] [Indexed: 01/24/2023] Open
Abstract
CRISPR-Cas9 is an RNA-guided DNA endonuclease involved in bacterial adaptive immunity and widely repurposed for genome editing in human cells, animals and plants. In bacteria, RNA molecules that guide Cas9's activity derive from foreign DNA fragments that are captured and integrated into the host CRISPR genomic locus by the Cas1-Cas2 CRISPR integrase. How cells generate the specific lengths of DNA required for integrase capture is a central unanswered question of type II-A CRISPR-based adaptive immunity. Here, we show that an integrase supercomplex comprising guide RNA and the proteins Cas1, Cas2, Csn2 and Cas9 generates precisely trimmed 30-base pair DNA molecules required for genome integration. The HNH active site of Cas9 catalyzes exonucleolytic DNA trimming by a mechanism that is independent of the guide RNA sequence. These results show that Cas9 possesses a distinct catalytic capacity for generating immunological memory in prokaryotes.
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Affiliation(s)
- Shrutee Jakhanwal
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.,Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Brady F Cress
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.,Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Pascal Maguin
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA
| | - Marco J Lobba
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.,Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Jennifer A Doudna
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.,California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA.,Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA 94720, USA.,Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, University of California, Berkeley, Berkeley, CA 94720, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.,Gladstone Institute of Data Science and Biotechnology, Gladstone Institutes, San Francisco, CA 94158, USA
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37
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Wu C, Tang D, Cheng J, Hu D, Yang Z, Ma X, He H, Yao S, Fu TM, Yu Y, Chen Q. Mechanisms of spacer acquisition by sequential assembly of the adaptation module in Synechocystis. Nucleic Acids Res 2021; 49:2973-2984. [PMID: 33619565 PMCID: PMC7969031 DOI: 10.1093/nar/gkab105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/03/2021] [Accepted: 02/09/2021] [Indexed: 02/05/2023] Open
Abstract
CRISPR–Cas immune systems process and integrate short fragments of DNA from new invaders as spacers into the host CRISPR locus to establish molecular memory of prior infection, which is also known as adaptation in the field. Some CRISPR–Cas systems rely on Cas1 and Cas2 to complete the adaptation process, which has been characterized in a few systems. In contrast, many other CRISPR–Cas systems require an additional factor of Cas4 for efficient adaptation, the mechanism of which remains less understood. Here we present biochemical reconstitution of the Synechocystis sp. PCC6803 type I-D adaptation system, X-ray crystal structures of Cas1–Cas2–prespacer complexes, and negative stained electron microscopy structure of the Cas4–Cas1 complex. Cas4 and Cas2 compete with each other to interact with Cas1. In the absence of prespacer, Cas4 but not Cas2 assembles with Cas1 into a very stable complex for processing the prespacer. Strikingly, the Cas1-prespacer complex develops a higher binding affinity toward Cas2 to form the Cas1–Cas2–prespacer ternary complex for integration. Together, we show a two-step sequential assembly mechanism for the type I-D adaptation module of Synechocystis, in which Cas4–Cas1 and Cas1–Cas2 function as two exclusive complexes for prespacer processing, capture, and integration.
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Affiliation(s)
- Chengyong Wu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Dongmei Tang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Jie Cheng
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Daojun Hu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Zejing Yang
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Xue Ma
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Haihuai He
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Shaohua Yao
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Tian-Min Fu
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210, USA.,The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210, USA
| | - Yamei Yu
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
| | - Qiang Chen
- State Key Laboratory of Biotherapy and Cancer Center, West China Hospital, Sichuan University, and Collaborative Innovation Center of Biotherapy, Chengdu 610041, P.R. China
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38
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León LM, Park AE, Borges AL, Zhang JY, Bondy-Denomy J. Mobile element warfare via CRISPR and anti-CRISPR in Pseudomonas aeruginosa. Nucleic Acids Res 2021; 49:2114-2125. [PMID: 33544853 PMCID: PMC7913775 DOI: 10.1093/nar/gkab006] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/04/2020] [Accepted: 01/05/2021] [Indexed: 12/27/2022] Open
Abstract
Bacteria deploy multiple defenses to prevent mobile genetic element (MGEs) invasion. CRISPR-Cas immune systems use RNA-guided nucleases to target MGEs, which counter with anti-CRISPR (Acr) proteins. Our understanding of the biology and co-evolutionary dynamics of the common Type I-C CRISPR-Cas subtype has lagged because it lacks an in vivo phage-host model system. Here, we show the anti-phage function of a Pseudomonas aeruginosa Type I-C CRISPR-Cas system encoded on a conjugative pKLC102 island, and its Acr-mediated inhibition by distinct MGEs. Seven genes with anti-Type I-C function (acrIC genes) were identified, many with highly acidic amino acid content, including previously described DNA mimic AcrIF2. Four of the acr genes were broad spectrum, also inhibiting I-E or I-F P. aeruginosa CRISPR-Cas subtypes. Dual inhibition comes at a cost, however, as simultaneous expression of Type I-C and I-F systems renders phages expressing the dual inhibitor AcrIF2 more sensitive to targeting. Mutagenesis of numerous acidic residues in AcrIF2 did not impair anti-I-C or anti-I-F function per se but did exacerbate inhibition defects during competition, suggesting that excess negative charge may buffer DNA mimics against competition. Like AcrIF2, five of the Acr proteins block Cascade from binding DNA, while two function downstream, likely preventing Cas3 recruitment or activity. One such inhibitor, AcrIC3, is found in an 'anti-Cas3' cluster within conjugative elements, encoded alongside bona fide Cas3 inhibitors AcrIF3 and AcrIE1. Our findings demonstrate an active battle between an MGE-encoded CRISPR-Cas system and its diverse MGE targets.
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Affiliation(s)
- Lina M León
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Allyson E Park
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Adair L Borges
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jenny Y Zhang
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joseph Bondy-Denomy
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
- Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Innovative Genomics Institute, Berkeley, CA 94720, USA
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39
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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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40
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Batool A, Malik F, Andrabi KI. Expansion of the CRISPR/Cas Genome-Sculpting Toolbox: Innovations, Applications and Challenges. Mol Diagn Ther 2020; 25:41-57. [PMID: 33185860 DOI: 10.1007/s40291-020-00500-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/10/2020] [Indexed: 12/18/2022]
Abstract
The emergence of the versatile gene-editing technology using programmable sequence-specific endonuclease system (CRISPR-Cas9) has instigated a major upheaval in biomedical research. In a brief span of time, CRISPR/Cas has been adopted by research labs around the globe because of its potential for significant progress and applicability in terms of efficiency, versatility and simplicity. It is a breakthrough technique for systematic genetic engineering, genome labelling, epigenetic and transcriptional modulation, and multiplexed gene editing, amongst others. This review provides an illustrative overview of the current research trends using CRISPR/Cas technology. We highlight the latest developments in CRISPR/Cas technique including CRISPR imaging, discovery of novel CRISPR systems, and applications in altering the genome, epigenome or RNA in different organisms. Finally, we address the potential challenges of this technique for its future use. Development of new CRISPR/Cas systems.
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Affiliation(s)
- Asiya Batool
- Division of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Branch Srinagar, Jammu, J&K, 190005, India. .,Department of Biotechnology, Science Block, University of Kashmir, Hazratbal, Srinagar, J&K, 190006, India.
| | - Fayaz Malik
- Division of Cancer Pharmacology, CSIR-Indian Institute of Integrative Medicine, Branch Srinagar, Jammu, J&K, 190005, India
| | - Khurshid Iqbal Andrabi
- Department of Biotechnology, Science Block, University of Kashmir, Hazratbal, Srinagar, J&K, 190006, India
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41
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Yu L, Marchisio MA. Types I and V Anti-CRISPR Proteins: From Phage Defense to Eukaryotic Synthetic Gene Circuits. Front Bioeng Biotechnol 2020; 8:575393. [PMID: 33102460 PMCID: PMC7556299 DOI: 10.3389/fbioe.2020.575393] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/31/2020] [Indexed: 12/26/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins), a prokaryotic RNA-mediated adaptive immune system, has been repurposed for gene editing and synthetic gene circuit construction both in bacterial and eukaryotic cells. In the last years, the emergence of the anti-CRISPR proteins (Acrs), which are natural OFF-switches for CRISPR-Cas, has provided a new means to control CRISPR-Cas activity and promoted a further development of CRISPR-Cas-based biotechnological toolkits. In this review, we focus on type I and type V-A anti-CRISPR proteins. We first narrate Acrs discovery and analyze their inhibitory mechanisms from a structural perspective. Then, we describe their applications in gene editing and transcription regulation. Finally, we discuss the potential future usage-and corresponding possible challenges-of these two kinds of anti-CRISPR proteins in eukaryotic synthetic gene circuits.
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42
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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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43
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Sasnauskas G, Siksnys V. CRISPR adaptation from a structural perspective. Curr Opin Struct Biol 2020; 65:17-25. [PMID: 32570107 DOI: 10.1016/j.sbi.2020.05.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 12/24/2022]
Abstract
Bacterial CRISPR-Cas systems provide adaptive immunity against viruses and other mobile genome elements. During the adaptation step cells become immunized by insertion of short fragments of foreign DNA, termed spacers, into the genomic region called a CRISPR array. Selection, processing and insertion of new spacers is an elaborate and precisely orchestrated reaction, which relies on the Cas1-Cas2 integrase complex and accessory proteins that vary among different types of CRISPR-Cas systems. This review focuses on CRISPR adaptation from the structural perspective, with the spotlight on adaptation proteins employed by type I and type II CRISPR-Cas systems.
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Affiliation(s)
- Giedrius Sasnauskas
- Institute of Biotechnology, Vilnius University, Sauletekio Av. 7, Vilnius 10257, Lithuania
| | - Virginijus Siksnys
- Institute of Biotechnology, Vilnius University, Sauletekio Av. 7, Vilnius 10257, Lithuania.
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44
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Abstract
CRISPR research began over 30 years ago with the incidental discovery of an unusual nucleotide arrangement in the Escherichia coli genome. It took 20 years to find the main function of CRISPR-Cas systems as an adaptive defence mechanism against invading nucleic acids, and our knowledge of their biology has steadily increased ever since. In parallel, the number of applications derived from CRISPR-Cas systems has risen spectacularly. The CRISPR-based genome editing tool is arguably the most exciting application in both basic and applied research. Lately, CRISPR-Cas research has partially shifted to the least understood aspect of its biology: the ability of CRISPR-Cas systems to acquire new immunities during the so-called adaptation step. To date, the most efficient natural system to readily acquire new spacers is the type II-A system of the gram-positive dairy bacterium Streptococcus thermophilus. The discovery of additional systems able to acquire new spacers will hopefully draw more attention to this step of CRISPR-Cas biology. This review focuses on the breakthroughs that have helped to unravel the adaptation phase and on questions that remain to be answered.
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Affiliation(s)
- Cas Mosterd
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada
| | - Geneviève M Rousseau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada
| | - Sylvain Moineau
- Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, QC G1V 0A6, Canada.,Groupe de recherche en écologie buccale, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada.,Félix d'Hérelle Reference Center for Bacterial Viruses, Faculté de médecine dentaire, Université Laval, QC G1V 0A6, Canada
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45
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Yu X, Wang L, Zou L, Li M, Li T, Hou L, Guo Y, Shen D, Sun G, Qu D, Cheng X, Chen L. Growth inhibition by bacterial Cas2Em proteins expressed in mammalian cells. Am J Transl Res 2020; 12:2499-2520. [PMID: 32655787 PMCID: PMC7344093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 04/18/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Clustered regularly interspaced short palindromic repeats (CRISPRs) and the CRISPR-associated (Cas) proteins are bacterial adaptive immune system for survival. In our previous study, we demonstrate that polyploid giant bacterial cells (PGBC) induced by Cas2 protein is a step required by new spacer acquisition reaction catalyzed by Cas1/Cas2 complex. We also demonstrated that a carboxyl terminal domain on Cas2Em (the protein Cas2 cloned from Elizabethkingia meningoseptica) is sufficient and enough for PGBC. Thus, the potential role of Cas2Em in microbial-host interaction was explored in this study. METHODS The impacts of Cas2Em on growth of both CHO-K1 and Hela cells were investigated. The subcellular localization and potential molecular target of Ca2Em were studied. RESULTS The growth of mammalian cells were inhibited by Cas2Em protein via G1 arresting and apoptosis. In addition, we also demonstrated that Cas2Em was tightly associated with nuclear outer membrane and could be immunoprecipitated with 14-3-3γ through a 30 amino acid domain (homology of CLK2). CONCLUSION Cas2Em significantly suppressed the growth of mammalian cells indicating Cas2 proteins play an important role in mammalian cells.
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Affiliation(s)
- Xin Yu
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
- Roche Innovation Center ShanghaiShanghai 201203, China
| | - Lei Wang
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Lin Zou
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Mengjie Li
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Tiansheng Li
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Linlin Hou
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Yameng Guo
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Danfeng Shen
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Guiqin Sun
- College of Medical Technology, Zhejiang Chinese Medical UniversityHangzhou 310053, Zhejiang, China
| | - Di Qu
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Xunjia Cheng
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
| | - Li Chen
- Department of Medical Microbiology, Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, School of Basic Medical Sciences, Fudan UniversityShanghai 200032, China
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46
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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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47
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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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48
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Wimmer F, Beisel CL. CRISPR-Cas Systems and the Paradox of Self-Targeting Spacers. Front Microbiol 2020; 10:3078. [PMID: 32038537 PMCID: PMC6990116 DOI: 10.3389/fmicb.2019.03078] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/19/2019] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas immune systems in bacteria and archaea record prior infections as spacers within each system’s CRISPR arrays. Spacers are normally derived from invasive genetic material and direct the immune system to complementary targets as part of future infections. However, not all spacers appear to be derived from foreign genetic material and instead can originate from the host genome. Their presence poses a paradox, as self-targeting spacers would be expected to induce an autoimmune response and cell death. In this review, we discuss the known frequency of self-targeting spacers in natural CRISPR-Cas systems, how these spacers can be incorporated into CRISPR arrays, and how the host can evade lethal attack. We also discuss how self-targeting spacers can become the basis for alternative functions performed by CRISPR-Cas systems that extend beyond adaptive immunity. Overall, the acquisition of genome-targeting spacers poses a substantial risk but can aid in the host’s evolution and potentially lead to or support new functionalities.
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Affiliation(s)
- Franziska Wimmer
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Chase L Beisel
- Helmholtz Institute for RNA-Based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany.,Medical Faculty, University of Würzburg, Würzburg, Germany
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49
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Ramachandran A, Summerville L, Learn BA, DeBell L, Bailey S. Processing and integration of functionally oriented prespacers in the Escherichia coli CRISPR system depends on bacterial host exonucleases. J Biol Chem 2019; 295:3403-3414. [PMID: 31914418 DOI: 10.1074/jbc.ra119.012196] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 12/20/2019] [Indexed: 12/22/2022] Open
Abstract
CRISPR-Cas systems provide bacteria with adaptive immunity against viruses. During spacer adaptation, the Cas1-Cas2 complex selects fragments of foreign DNA, called prespacers, and integrates them into CRISPR arrays in an orientation that provides functional immunity. Cas4 is involved in both the trimming of prespacers and the cleavage of protospacer adjacent motif (PAM) in several type I CRISPR-Cas systems, but how the prespacers are processed in systems lacking Cas4, such as the type I-E and I-F systems, is not understood. In Escherichia coli, which has a type I-E system, Cas1-Cas2 preferentially selects prespacers with 3' overhangs via specific recognition of a PAM, but how these prespacers are integrated in a functional orientation in the absence of Cas4 is not known. Using a biochemical approach with purified proteins, as well as integration, prespacer protection, sequencing, and quantitative PCR assays, we show here that the bacterial 3'-5' exonucleases DnaQ and ExoT can trim long 3' overhangs of prespacers and promote integration in the correct orientation. We found that trimming by these exonucleases results in an asymmetric intermediate, because Cas1-Cas2 protects the PAM sequence, which helps to define spacer orientation. Our findings implicate the E. coli host 3'-5' exonucleases DnaQ and ExoT in spacer adaptation and reveal a mechanism by which spacer orientation is defined in E. coli.
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Affiliation(s)
- Anita Ramachandran
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Lesley Summerville
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Brian A Learn
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Lily DeBell
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205
| | - Scott Bailey
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland 21205; Department of Biophysics and Biophysical Chemistry, School of Medicine, Johns Hopkins University, Baltimore, Maryland 21205.
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50
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Yoganand KN, Muralidharan M, Nimkar S, Anand B. Fidelity of prespacer capture and processing is governed by the PAM-mediated interactions of Cas1-2 adaptation complex in CRISPR-Cas type I-E system. J Biol Chem 2019; 294:20039-20053. [PMID: 31748409 PMCID: PMC6937570 DOI: 10.1074/jbc.ra119.009438] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2019] [Revised: 11/18/2019] [Indexed: 12/11/2022] Open
Abstract
Prokaryotes deploy CRISPR-Cas-based RNA-guided adaptive immunity to fend off mobile genetic elements such as phages and plasmids. During CRISPR adaptation, which is the first stage of CRISPR immunity, the Cas1-2 integrase complex captures invader-derived prespacer DNA and specifically integrates it at the leader-repeat junction as spacers. For this integration, several variants of CRISPR-Cas systems use Cas4 as an indispensable nuclease for selectively processing the protospacer adjacent motif (PAM) containing prespacers to a defined length. Surprisingly, however, a few CRISPR-Cas systems, such as type I-E, are bereft of Cas4. Despite the absence of Cas4, how the prespacers show impeccable conservation for length and PAM selection in type I-E remains intriguing. Here, using in vivo and in vitro integration assays, deep sequencing, and exonuclease footprinting, we show that Cas1-2/I-E-via the type I-E-specific extended C-terminal tail of Cas1-displays intrinsic affinity for PAM containing prespacers of variable length in Escherichia coli Although Cas1-2/I-E does not prune the prespacers, its binding protects the prespacer boundaries from exonuclease action. This ensures the pruning of exposed ends by exonucleases to aptly sized substrates for integration into the CRISPR locus. In summary, our work reveals that in a few CRISPR-Cas variants, such as type I-E, the specificity of PAM selection resides with Cas1-2, whereas the prespacer processing is co-opted by cellular non-Cas exonucleases, thereby offsetting the need for Cas4.
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Affiliation(s)
- Kakimani Nagarajan Yoganand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Manasasri Muralidharan
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Siddharth Nimkar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
| | - Baskaran Anand
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, India
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