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Kanbar K, El Darzi R, Jaalouk DE. Precision oncology revolution: CRISPR-Cas9 and PROTAC technologies unleashed. Front Genet 2024; 15:1434002. [PMID: 39144725 PMCID: PMC11321987 DOI: 10.3389/fgene.2024.1434002] [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: 05/16/2024] [Accepted: 07/02/2024] [Indexed: 08/16/2024] Open
Abstract
Cancer continues to present a substantial global health challenge, with its incidence and mortality rates persistently reflecting its significant impact. The emergence of precision oncology has provided a breakthrough in targeting oncogenic drivers previously deemed "undruggable" by conventional therapeutics and by limiting off-target cytotoxicity. Two groundbreaking technologies that have revolutionized the field of precision oncology are primarily CRISPR-Cas9 gene editing and more recently PROTAC (PROteolysis TArgeting Chimeras) targeted protein degradation technology. CRISPR-Cas9, in particular, has gained widespread recognition and acclaim due to its remarkable ability to modify DNA sequences precisely. Rather than editing the genetic code, PROTACs harness the ubiquitin proteasome degradation machinery to degrade proteins of interest selectively. Even though CRISPR-Cas9 and PROTAC technologies operate on different principles, they share a common goal of advancing precision oncology whereby both approaches have demonstrated remarkable potential in preclinical and promising data in clinical trials. CRISPR-Cas9 has demonstrated its clinical potential in this field due to its ability to modify genes directly and indirectly in a precise, efficient, reversible, adaptable, and tissue-specific manner, and its potential as a diagnostic tool. On the other hand, the ability to administer in low doses orally, broad targeting, tissue specificity, and controllability have reinforced the clinical potential of PROTAC. Thus, in the field of precision oncology, gene editing using CRISPR technology has revolutionized targeted interventions, while the emergence of PROTACs has further expanded the therapeutic landscape by enabling selective protein degradation. Rather than viewing them as mutually exclusive or competing methods in the field of precision oncology, their use is context-dependent (i.e., based on the molecular mechanisms of the disease) and they potentially could be used synergistically complementing the strengths of CRISPR and vice versa. Herein, we review the current status of CRISPR and PROTAC designs and their implications in the field of precision oncology in terms of clinical potential, clinical trial data, limitations, and compare their implications in precision clinical oncology.
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Affiliation(s)
- Karim Kanbar
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon
| | - Roy El Darzi
- Faculty of Medicine, American University of Beirut, Beirut, Lebanon
- Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon
| | - Diana E. Jaalouk
- Department of Biology, Faculty of Arts and Sciences, American University of Beirut, Beirut, Lebanon
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2
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Yadalam PK, Arumuganainar D, Anegundi RV, Shrivastava D, Alftaikhah SAA, Almutairi HA, Alobaida MA, Alkaberi AA, Srivastava KC. CRISPR-Cas-Based Adaptive Immunity Mediates Phage Resistance in Periodontal Red Complex Pathogens. Microorganisms 2023; 11:2060. [PMID: 37630620 PMCID: PMC10459013 DOI: 10.3390/microorganisms11082060] [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: 06/13/2023] [Revised: 07/23/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
Periodontal diseases are polymicrobial immune-inflammatory diseases that can severely destroy tooth-supporting structures. The critical bacteria responsible for this destruction include red complex bacteria such as Porphoromonas gingivalis, Tanerella forsythia and Treponema denticola. These organisms have developed adaptive immune mechanisms against bacteriophages/viruses, plasmids and transposons through clustered regularly interspaced short palindromic repeats (CRISPR) and their associated proteins (Cas). The CRISPR-Cas system contributes to adaptive immunity, and this acquired genetic immune system of bacteria may contribute to moderating the microbiome of chronic periodontitis. The current research examined the role of the CRISPR-Cas system of red complex bacteria in the dysbiosis of oral bacteriophages in periodontitis. Whole-genome sequences of red complex bacteria were obtained and investigated for CRISPR using the CRISPR identification tool. Repeated spacer sequences were analyzed for homologous sequences in the bacteriophage genome and viromes using BLAST algorithms. The results of the BLAST spacer analysis for T. denticola spacers had a 100% score (e value with a bacillus phage), and the results for T. forsthyia and P. gingivalis had a 56% score with a pectophage and cellulophage (e value: 0.21), respectively. The machine learning model of the identified red complex CRISPR sequences predicts with area an under the curve (AUC) accuracy of 100 percent, indicating phage inhibition. These results infer that red complex bacteria could significantly inhibit viruses and phages with CRISPR immune sequences. Therefore, the role of viruses and bacteriophages in modulating sub-gingival bacterial growth in periodontitis is limited or questionable.
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Affiliation(s)
- Pradeep Kumar Yadalam
- Department of Periodontics, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha Dental College and Hospitals, Saveetha University, Chennai 600077, India;
| | - Deepavalli Arumuganainar
- Department of Periodontics, Ragas Dental College and Hospital, 2/102, East Coast Road, Uthandi, Chennai 600119, India;
| | - Raghavendra Vamsi Anegundi
- Department of Periodontics, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha Dental College and Hospitals, Saveetha University, Chennai 600077, India;
| | - Deepti Shrivastava
- Periodontics Division, Preventive Dentistry Department, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia
| | | | - Haifa Ali Almutairi
- College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia; (S.A.A.A.); (H.A.A.)
| | - Muhanad Ali Alobaida
- General Dentist, Ministry of Health, Riyadh 12613, Saudi Arabia; (M.A.A.); (A.A.A.)
| | | | - Kumar Chandan Srivastava
- Oral Medicine & Maxillofacial Radiology Division, Department of Oral & Maxillofacial Surgery & Diagnostic Sciences, College of Dentistry, Jouf University, Sakaka 72345, Saudi Arabia;
- Department of Oral Medicine and Radiology, Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai 602105, India
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3
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Ahmadi SE, Soleymani M, Shahriyary F, Amirzargar MR, Ofoghi M, Fattahi MD, Safa M. Viral vectors and extracellular vesicles: innate delivery systems utilized in CRISPR/Cas-mediated cancer therapy. Cancer Gene Ther 2023:10.1038/s41417-023-00597-z. [PMID: 36854897 PMCID: PMC9971689 DOI: 10.1038/s41417-023-00597-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2022] [Revised: 01/13/2023] [Accepted: 02/01/2023] [Indexed: 03/02/2023]
Abstract
Gene editing-based therapeutic strategies grant the power to override cell machinery and alter faulty genes contributing to disease development like cancer. Nowadays, the principal tool for gene editing is the clustered regularly interspaced short palindromic repeats-associated nuclease 9 (CRISPR/Cas9) system. In order to bring this gene-editing system from the bench to the bedside, a significant hurdle remains, and that is the delivery of CRISPR/Cas to various target cells in vivo and in vitro. The CRISPR-Cas system can be delivered into mammalian cells using various strategies; among all, we have reviewed recent research around two natural gene delivery systems that have been proven to be compatible with human cells. Herein, we have discussed the advantages and limitations of viral vectors, and extracellular vesicles (EVs) in delivering the CRISPR/Cas system for cancer therapy purposes.
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Affiliation(s)
- Seyed Esmaeil Ahmadi
- grid.411746.10000 0004 4911 7066Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Maral Soleymani
- grid.411230.50000 0000 9296 6873School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Fahimeh Shahriyary
- grid.411746.10000 0004 4911 7066Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Reza Amirzargar
- grid.411746.10000 0004 4911 7066Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Mahya Ofoghi
- Division of Clinical Laboratory, Tehran Hospital of Petroleum Industry, Tehran, Iran ,grid.411600.2Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Davood Fattahi
- grid.411600.2Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Majid Safa
- Department of Hematology and Blood Banking, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, Iran.
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Abstract
Phage therapy is challenged by the frequent emergence of bacterial resistance to phages. As an interspecies signaling molecule, indole plays important roles in regulating bacterial behaviors. However, it is unclear whether indole is involved in the phage-bacterium interactions. Here, we report that indole modulated phage resistance of Pseudomonas aeruginosa PAO1. Specifically, we found that the type IV pilus (T4P) acts as an important receptor for P. aeruginosa phages vB_Pae_S1 and vB_Pae_TR, and indole could protect P. aeruginosa against phage infection via decreasing the T4P-mediated phage adsorption. Further investigation demonstrated that indole downregulated the expression of genes pilA, pilB, and pilQ, which are essential for T4P assembly and activity. Indole inhibits phage attacks, but our data suggest that indole functions not through interfering with the AHL-based QS pathway, although las quorum sensing (QS) of P. aeruginosa PAO1 were reported to promote phage infection. Our finding confirms the important roles of indole in virus-host interactions, which will provide important enlightenment in promoting phage therapy for P. aeruginosa infections. IMPORTANCE Our finding is significant with respect to the study of the interactions between phage and host. Although the important roles of indole in bacterial physiology have been revealed, no direct examples of indole participating in phage-host interactions were reported. This study reports that indole could modulate the phage resistance of indole-nonproducing Pseudomonas aeruginosa PAO1 through inhibition of phage adsorption mechanism. Our finding will be significant for guiding phage therapy and fill some gaps in the field of phage-host interactions.
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Nidhi S, Tripathi P, Tripathi V. Phylogenetic Analysis of Anti-CRISPR and Member Addition in the Families. Mol Biotechnol 2023; 65:273-281. [PMID: 36109427 DOI: 10.1007/s12033-022-00558-1] [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: 01/10/2022] [Accepted: 09/05/2022] [Indexed: 01/18/2023]
Abstract
CRISPR-Cas is a widespread anti-viral adaptive immune system in the microorganisms. Viruses living in bacteria or some phages carry anti-CRISPR proteins to evade immunity by CRISPR-Cas. The anti-CRISPR proteins are prevalent in phages capable of lying dormant in a CRISPR-carrying host, while their orthologs frequently found in virulent phages. Here, we propose a probabilistic strategy of ancestral sequence reconstruction (ASR) and Hidden Markov Model (HMM) profile search to fish out sequences of anti-CRISPR proteins from environmental metagenomic, human microbiome metagenomic, human microbiome reference genome, and NCBI's non-redundant databases. Our results revealed that the metagenome database dark matter might contain anti-CRISPR encoding genes.
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Affiliation(s)
- Sweta Nidhi
- Department of Genomics and Bioinformatics, Aix-Marseille University, 13007, Marseille, France
| | - Pooja Tripathi
- Department of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh, 211007, India
| | - Vijay Tripathi
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh, 211007, India.
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Yang Y, Li D, Wan F, Chen B, Wu G, Li F, Ren Y, Liang P, Wan J, Songyang Z. Identification and Analysis of Small Molecule Inhibitors of CRISPR-Cas9 in Human Cells. Cells 2022; 11:3574. [PMID: 36429003 PMCID: PMC9688475 DOI: 10.3390/cells11223574] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/07/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022] Open
Abstract
Genome editing tools based on CRISPR-Cas systems can repair genetic mutations in situ; however, off-target effects and DNA damage lesions that result from genome editing remain major roadblocks to its full clinical implementation. Protein and chemical inhibitors of CRISPR-Cas systems may reduce off-target effects and DNA damage. Here we describe the identification of several lead chemical inhibitors that could specifically inhibit the activity of Streptococcus pyogenes Cas9 (SpCas9). In addition, we obtained derivatives of lead inhibitors that could penetrate the cell membrane and inhibit SpCas9 in cellulo. Two of these compounds, SP2 and SP24, were able to improve the specificity of SpCas9 in cellulo at low-micromolar concentration. Furthermore, microscale thermophoresis (MST) assays showed that SP24 might inhibit SpCas9 activity by interacting with both the SpCas9 protein and the SpCas9-gRNA ribonucleoprotein complex. Taken together, SP24 is a novel chemical inhibitor of SpCas9 which has the potential to enhance therapies that utilize SpCas9.
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Affiliation(s)
- Yue Yang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Donghua Li
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Fen Wan
- International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Bohong Chen
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Guanglan Wu
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Feng Li
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Yanliang Ren
- International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Puping Liang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jian Wan
- International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Zhou Songyang
- MOE Key Laboratory of Gene Function and Regulation and Guangzhou Key Laboratory of Healthy Aging Research, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
- Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
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7
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Lan T, Que H, Luo M, Zhao X, Wei X. Genome editing via non-viral delivery platforms: current progress in personalized cancer therapy. Mol Cancer 2022; 21:71. [PMID: 35277177 PMCID: PMC8915502 DOI: 10.1186/s12943-022-01550-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/24/2022] [Indexed: 02/08/2023] Open
Abstract
Cancer is a severe disease that substantially jeopardizes global health. Although considerable efforts have been made to discover effective anti-cancer therapeutics, the cancer incidence and mortality are still growing. The personalized anti-cancer therapies present themselves as a promising solution for the dilemma because they could precisely destroy or fix the cancer targets based on the comprehensive genomic analyses. In addition, genome editing is an ideal way to implement personalized anti-cancer therapy because it allows the direct modification of pro-tumor genes as well as the generation of personalized anti-tumor immune cells. Furthermore, non-viral delivery system could effectively transport genome editing tools (GETs) into the cell nucleus with an appreciable safety profile. In this manuscript, the important attributes and recent progress of GETs will be discussed. Besides, the laboratory and clinical investigations that seek for the possibility of combining non-viral delivery systems with GETs for the treatment of cancer will be assessed in the scope of personalized therapy.
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Affiliation(s)
- Tianxia Lan
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China
| | - Haiying Que
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China
| | - Min Luo
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China
| | - Xia Zhao
- Department of Gynecology and Obstetrics, Development and Related Diseases of Women and Children Key Laboratory of Sichuan Province, Key Laboratory of Birth Defects and Related Diseases of Women and Children, Ministry of Education, West China Second Hospital, Sichuan University, Sichuan, 610041, Chengdu, China.
| | - Xiawei Wei
- Laboratory of Aging Research and Cancer Drug Target, State Key Laboratory of Biotherapy, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, No. 17, Block 3, Southern Renmin Road, Sichuan, 610041, Chengdu, China.
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8
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Liu X, Zhang L, Xiu Y, Gao T, Huang L, Xie Y, Yang L, Wang W, Wang P, Zhang Y, Yang M, Feng Y. Insights into the dual functions of AcrIF14 during the inhibition of type I-F CRISPR-Cas surveillance complex. Nucleic Acids Res 2021; 49:10178-10191. [PMID: 34432044 PMCID: PMC8464039 DOI: 10.1093/nar/gkab738] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 07/20/2021] [Accepted: 08/17/2021] [Indexed: 11/21/2022] Open
Abstract
CRISPR–Cas systems are bacterial adaptive immune systems, and phages counteract these systems using many approaches such as producing anti-CRISPR (Acr) proteins. Here, we report the structures of both AcrIF14 and its complex with the crRNA-guided surveillance (Csy) complex. Our study demonstrates that apart from interacting with the Csy complex to block the hybridization of target DNA to the crRNA, AcrIF14 also endows the Csy complex with the ability to interact with non-sequence-specific dsDNA as AcrIF9 does. Further structural studies of the Csy–AcrIF14–dsDNA complex and biochemical studies uncover that the PAM recognition loop of the Cas8f subunit of the Csy complex and electropositive patches within the N-terminal domain of AcrIF14 are essential for the non-sequence-specific dsDNA binding to the Csy–AcrIF14 complex, which is different from the mechanism of AcrIF9. Our findings highlight the prevalence of Acr-induced non-specific DNA binding and shed light on future studies into the mechanisms of such Acr proteins.
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Affiliation(s)
- Xi Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Laixing Zhang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Tsinghua-Peking Center for Life Sciences, 100084 Beijing, China
| | - Yu Xiu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Teng Gao
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Ling Huang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Yongchao Xie
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Lingguang Yang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Wenhe Wang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Tsinghua-Peking Center for Life Sciences, 100084 Beijing, China
| | - Peiyi Wang
- Cryo-EM Centre, Department of Biology, Southern University of Science and Technology, 515055 Shenzhen, China
| | - Yi Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
| | - Maojun Yang
- Ministry of Education Key Laboratory of Protein Science, Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Tsinghua-Peking Center for Life Sciences, 100084 Beijing, China
| | - Yue Feng
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing Key Laboratory of Bioprocess, State Key Laboratory of Chemical Resource Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, 100029 Beijing, China
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9
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Nguyen AQ, Vu HP, Nguyen LN, Wang Q, Djordjevic SP, Donner E, Yin H, Nghiem LD. Monitoring antibiotic resistance genes in wastewater treatment: Current strategies and future challenges. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 783:146964. [PMID: 33866168 DOI: 10.1016/j.scitotenv.2021.146964] [Citation(s) in RCA: 107] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 05/29/2023]
Abstract
Antimicrobial resistance (AMR) is a growing threat to human and animal health. Progress in molecular biology has revealed new and significant challenges for AMR mitigation given the immense diversity of antibiotic resistance genes (ARGs), the complexity of ARG transfer, and the broad range of omnipresent factors contributing to AMR. Municipal, hospital and abattoir wastewater are collected and treated in wastewater treatment plants (WWTPs), where the presence of diverse selection pressures together with a highly concentrated consortium of pathogenic/commensal microbes create favourable conditions for the transfer of ARGs and proliferation of antibiotic resistant bacteria (ARB). The rapid emergence of antibiotic resistant pathogens of clinical and veterinary significance over the past 80 years has re-defined the role of WWTPs as a focal point in the fight against AMR. By reviewing the occurrence of ARGs in wastewater and sludge and the current technologies used to quantify ARGs and identify ARB, this paper provides a research roadmap to address existing challenges in AMR control via wastewater treatment. Wastewater treatment is a double-edged sword that can act as either a pathway for AMR spread or as a barrier to reduce the environmental release of anthropogenic AMR. State of the art ARB identification technologies, such as metagenomic sequencing and fluorescence-activated cell sorting, have enriched ARG/ARB databases, unveiled keystone species in AMR networks, and improved the resolution of AMR dissemination models. Data and information provided in this review highlight significant knowledge gaps. These include inconsistencies in ARG reporting units, lack of ARG/ARB monitoring surrogates, lack of a standardised protocol for determining ARG removal via wastewater treatments, and the inability to support appropriate risk assessment. This is due to a lack of standard monitoring targets and agreed threshold values, and paucity of information on the ARG-pathogen host relationship and risk management. These research gaps need to be addressed and research findings need to be transformed into practical guidance for WWTP operators to enable effective progress towards mitigating the evolution and spread of AMR.
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Affiliation(s)
- Anh Q Nguyen
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Hang P Vu
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Luong N Nguyen
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Qilin Wang
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Steven P Djordjevic
- Institute of Infection, Immunity and Innovation, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Erica Donner
- Future Industries Institute, University of South Australia, Mawson Lakes, SA 5095, Australia
| | - Huabing Yin
- School of Engineering, University of Glasgow, Glasgow G12 8LT, UK
| | - Long D Nghiem
- Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology Sydney, Ultimo, NSW 2007, Australia; Institute of Environmental Sciences, Nguyen Tat Thanh University, Ho Chi Minh City, Viet Nam.
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10
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Prakash A, Kumar M. Characterizing the transcripts of Leptospira CRISPR I-B array and its processing with endoribonuclease LinCas6. Int J Biol Macromol 2021; 182:785-795. [PMID: 33862076 DOI: 10.1016/j.ijbiomac.2021.04.066] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/08/2021] [Accepted: 04/10/2021] [Indexed: 12/26/2022]
Abstract
In Leptospira interrogans serovar Copenhageni, the CRISPR-Cas I-B locus possesses a CRISPR array between the two independent cas-operons. Using the reverse transcription-PCR and the in vitro endoribonuclease assay with Cas6 of Leptospira (LinCas6), we account that the CRISPR is transcriptionally active and is conventionally processed. The LinCas6 specifically excises at one site within the synthetic cognate repeat RNA or the repeats of precursor-CRISPR RNA (pre-crRNA) in the sense direction. In contrast, the antisense repeat RNA is cleaved at multiple sites. LinCas6 functions as a single turnover endoribonuclease on its repeat RNA substrate, where substitution of one of predicted active site residues (His38) resulted in reduced activity. This study highlights the comprehensive understanding of the Leptospira CRISPR array transcription and its processing by LinCas6 that is central to RNA-mediated CRISPR-Cas I-B adaptive immunity.
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Affiliation(s)
- Aman Prakash
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Manish Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
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11
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Nidhi S, Anand U, Oleksak P, Tripathi P, Lal JA, Thomas G, Kuca K, Tripathi V. Novel CRISPR-Cas Systems: An Updated Review of the Current Achievements, Applications, and Future Research Perspectives. Int J Mol Sci 2021; 22:3327. [PMID: 33805113 PMCID: PMC8036902 DOI: 10.3390/ijms22073327] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 12/11/2022] Open
Abstract
According to Darwin's theory, endless evolution leads to a revolution. One such example is the Clustered Regularly Interspaced Palindromic Repeats (CRISPR)-Cas system, an adaptive immunity system in most archaea and many bacteria. Gene editing technology possesses a crucial potential to dramatically impact miscellaneous areas of life, and CRISPR-Cas represents the most suitable strategy. The system has ignited a revolution in the field of genetic engineering. The ease, precision, affordability of this system is akin to a Midas touch for researchers editing genomes. Undoubtedly, the applications of this system are endless. The CRISPR-Cas system is extensively employed in the treatment of infectious and genetic diseases, in metabolic disorders, in curing cancer, in developing sustainable methods for fuel production and chemicals, in improving the quality and quantity of food crops, and thus in catering to global food demands. Future applications of CRISPR-Cas will provide benefits for everyone and will save countless lives. The technology is evolving rapidly; therefore, an overview of continuous improvement is important. In this review, we aim to elucidate the current state of the CRISPR-Cas revolution in a tailor-made format from its discovery to exciting breakthroughs at the application level and further upcoming trends related to opportunities and challenges including ethical concerns.
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Affiliation(s)
- Sweta Nidhi
- Department of Genomics and Bioinformatics, Aix-Marseille University, 13007 Marseille, France;
| | - Uttpal Anand
- Department of Life Sciences and the National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel;
| | - Patrik Oleksak
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic;
| | - Pooja Tripathi
- Department of Computational Biology and Bioinformatics, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj 211007, Uttar Pradesh, India;
| | - Jonathan A. Lal
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj 211007, Uttar Pradesh, India; (J.A.L.); (G.T.)
| | - George Thomas
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj 211007, Uttar Pradesh, India; (J.A.L.); (G.T.)
| | - Kamil Kuca
- Department of Chemistry, Faculty of Science, University of Hradec Kralove, 50003 Hradec Kralove, Czech Republic;
| | - Vijay Tripathi
- Department of Molecular and Cellular Engineering, Jacob Institute of Biotechnology and Bioengineering, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj 211007, Uttar Pradesh, India; (J.A.L.); (G.T.)
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12
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Zhan S, Wang Y, Chen X. RNA virus-encoded microRNAs: biogenesis, functions and perspectives on application. ACTA ACUST UNITED AC 2020; 2:15. [PMID: 33209991 PMCID: PMC7548135 DOI: 10.1186/s41544-020-00056-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 09/22/2020] [Indexed: 12/12/2022]
Abstract
MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression at the posttranscriptional level and play a crucial role in development and many diseases. The discovery of miRNAs has greatly expanded our understanding of the intricate scenario of genome-wide regulation. Over the last two decades, hundreds of virus-encoded miRNAs have been identified, most of which are from DNA viruses. Although the number of reported RNA virus-derived miRNAs is increasing, current knowledge of their roles in physiological and pathological processes has remained lacking. In this review, we discuss the biogenesis and biological functions of RNA virus- encoded miRNAs and their proposed roles in virus-host interactions and further underscore their potential value in the diagnosis and treatment of viral diseases.
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Affiliation(s)
- Shoubin Zhan
- Nanjing Drum Tower Hospital Center of Molecular Diagnostic and Therapy, State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, NJU Advanced Institute of Life Sciences (NAILS), School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023 China
| | - Yanbo Wang
- Nanjing Drum Tower Hospital Center of Molecular Diagnostic and Therapy, State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, NJU Advanced Institute of Life Sciences (NAILS), School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023 China
| | - Xi Chen
- Nanjing Drum Tower Hospital Center of Molecular Diagnostic and Therapy, State Key Laboratory of Pharmaceutical Biotechnology and Department of Physiology, Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology, NJU Advanced Institute of Life Sciences (NAILS), School of Life Sciences, Nanjing University, 163 Xianlin Avenue, Nanjing, 210023 China
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13
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Behler J, Hess WR. Approaches to study CRISPR RNA biogenesis and the key players involved. Methods 2020; 172:12-26. [PMID: 31325492 DOI: 10.1016/j.ymeth.2019.07.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/29/2019] [Accepted: 07/15/2019] [Indexed: 12/26/2022] Open
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins provide an inheritable and adaptive immune system against phages and foreign genetic elements in many bacteria and archaea. The three stages of CRISPR-Cas immunity comprise adaptation, CRISPR RNA (crRNA) biogenesis and interference. The maturation of the pre-crRNA into mature crRNAs, short guide RNAs that target invading nucleic acids, is crucial for the functionality of CRISPR-Cas defense systems. Mature crRNAs assemble with Cas proteins into the ribonucleoprotein (RNP) effector complex and guide the Cas nucleases to the cognate foreign DNA or RNA target. Experimental approaches to characterize these crRNAs, the specific steps toward their maturation and the involved factors, include RNA-seq analyses, enzyme assays, methods such as cryo-electron microscopy, the crystallization of proteins, or UV-induced protein-RNA crosslinking coupled to mass spectrometry analysis. Complex and multiple interactions exist between CRISPR-cas-encoded specific riboendonucleases such as Cas6, Cas5d and Csf5, endonucleases with dual functions in maturation and interference such as the enzymes of the Cas12 and Cas13 families, and nucleases belonging to the cell's degradosome such as RNase E, PNPase and RNase J, both in the maturation as well as in interference. The results of these studies have yielded a picture of unprecedented diversity of sequences, enzymes and biochemical mechanisms.
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Affiliation(s)
- Juliane Behler
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104 Freiburg, Germany
| | - Wolfgang R Hess
- University of Freiburg, Faculty of Biology, Genetics and Experimental Bioinformatics, Schänzlestr. 1, D-79104 Freiburg, Germany; University of Freiburg, Freiburg Institute for Advanced Studies, Albertstr. 19, D-79104 Freiburg, Germany.
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14
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Zhu A, Liao X, Li S, Zhao H, Chen L, Xu M, Duan X. HBV cccDNA and Its Potential as a Therapeutic Target. J Clin Transl Hepatol 2019; 7:258-262. [PMID: 31608218 PMCID: PMC6783673 DOI: 10.14218/jcth.2018.00054] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 04/02/2019] [Accepted: 07/10/2019] [Indexed: 12/13/2022] Open
Abstract
Chronic hepatitis B virus infection continues to be a major health burden worldwide. It can cause various degrees of liver damage and is strongly associated with the development of liver cirrhosis and hepatocellular carcinoma. Covalently closed circular DNA in the nucleus of infected cells cannot be disabled by present therapies which may lead to HBV persistence and relapse. In this review, we summarized the current knowledge on hepatitis B virus covalently closed circular DNA and its potential role as a therapeutic target.
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Affiliation(s)
- Anjing Zhu
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
| | - Xinzhong Liao
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
| | - Shuang Li
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
| | - Hang Zhao
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
| | - Limin Chen
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
| | - Min Xu
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
| | - Xiaoqiong Duan
- Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu, China
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15
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Peng R, Li Z, Xu Y, He S, Peng Q, Wu LA, Wu Y, Qi J, Wang P, Shi Y, Gao GF. Structural insight into multistage inhibition of CRISPR-Cas12a by AcrVA4. Proc Natl Acad Sci U S A 2019; 116:18928-18936. [PMID: 31467167 PMCID: PMC6754591 DOI: 10.1073/pnas.1909400116] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Prokaryotes possess CRISPR-Cas systems to exclude parasitic predators, such as phages and mobile genetic elements (MGEs). These predators, in turn, encode anti-CRISPR (Acr) proteins to evade the CRISPR-Cas immunity. Recently, AcrVA4, an Acr protein inhibiting the CRISPR-Cas12a system, was shown to diminish Lachnospiraceae bacterium Cas12a (LbCas12a)-mediated genome editing in human cells, but the underlying mechanisms remain elusive. Here we report the cryo-EM structures of AcrVA4 bound to CRISPR RNA (crRNA)-loaded LbCas12a and found AcrVA4 could inhibit LbCas12a at several stages of the CRISPR-Cas working pathway, different from other characterized type I/II Acr inhibitors which target only 1 stage. First, it locks the conformation of the LbCas12a-crRNA complex to prevent target DNA-crRNA hybridization. Second, it interacts with the LbCas12a-crRNA-dsDNA complex to release the bound DNA before cleavage. Third, AcrVA4 binds the postcleavage LbCas12a complex to possibly block enzyme recycling. These findings highlight the multifunctionality of AcrVA4 and provide clues for developing regulatory genome-editing tools.
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Affiliation(s)
- Ruchao Peng
- Savaid Medical School, University of Chinese Academy of Sciences, 100049 Beijing, China
- Chinese Academy of Sciences (CAS) Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Zhiteng Li
- Savaid Medical School, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Ying Xu
- School of Life Sciences, University of Science and Technology of China, 230026 Hefei, China
| | - Shaoshuai He
- Savaid Medical School, University of Chinese Academy of Sciences, 100049 Beijing, China
| | - Qi Peng
- Chinese Academy of Sciences (CAS) Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Lian-Ao Wu
- Institute of Physical Science and Information Technology, Anhui University, 230039 Hefei, China
| | - Ying Wu
- School of Basic Medical Sciences, Wuhan University, 430071 Wuhan, China
| | - Jianxun Qi
- Savaid Medical School, University of Chinese Academy of Sciences, 100049 Beijing, China
- Chinese Academy of Sciences (CAS) Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
| | - Peiyi Wang
- Department of Biology, Southern University of Science and Technology, 518055 Shenzhen, China
| | - Yi Shi
- Savaid Medical School, University of Chinese Academy of Sciences, 100049 Beijing, China;
- Chinese Academy of Sciences (CAS) Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
- Center for Influenza Research and Early-Warning, Chinese Academy of Sciences, 100101 Beijing, China
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, 518112 Shenzhen, China
| | - George F Gao
- Savaid Medical School, University of Chinese Academy of Sciences, 100049 Beijing, China;
- Chinese Academy of Sciences (CAS) Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, 100101 Beijing, China
- Center for Influenza Research and Early-Warning, Chinese Academy of Sciences, 100101 Beijing, China
- Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, 518112 Shenzhen, China
- National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, 102206 Beijing, China
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16
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Lam TJ, Ye Y. CRISPRs for Strain Tracking and Their Application to Microbiota Transplantation Data Analysis. CRISPR J 2019; 2:41-50. [PMID: 30820491 PMCID: PMC6390457 DOI: 10.1089/crispr.2018.0046] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 11/29/2018] [Accepted: 01/09/2019] [Indexed: 12/17/2022] Open
Abstract
CRISPR-Cas systems are adaptive immune systems naturally found in bacteria and archaea. Prokaryotes use these immune systems to defend against invaders, which include phages, plasmids, and other mobile genetic elements. Relying on the integration of spacers derived from invader sequences (protospacers) into CRISPR loci (forming spacers flanked by repeats), CRISPR-Cas systems are able to store the memory of past immunological encounters. While CRISPR-Cas systems have evolved in response to invading mobile genetic elements, invaders have also developed mechanisms to avoid detection. As a result of an arms race between CRISPR-Cas systems and their targets, CRISPR arrays typically undergo rapid turnover of spacers through the acquisition and loss events. Additionally, microbiomes of different individuals rarely share spacers. Here, we present a computational pipeline, CRISPRtrack, for strain tracking based on CRISPR spacer content, and we applied it to fecal transplantation microbiome data to study the retention of donor strains in recipients. Our results demonstrate the potential use of CRISPRs as a simple yet effective tool for donor-strain tracking in fecal transplantation and as a general purpose tool for quantifying microbiome similarity.
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Affiliation(s)
- Tony J Lam
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana
| | - Yuzhen Ye
- School of Informatics, Computing, and Engineering, Indiana University, Bloomington, Indiana
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17
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Genome comparison of different Zymomonas mobilis strains provides insights on conservation of the evolution. PLoS One 2018; 13:e0195994. [PMID: 29694430 PMCID: PMC5919020 DOI: 10.1371/journal.pone.0195994] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 04/04/2018] [Indexed: 11/19/2022] Open
Abstract
Zymomonas mobilis has the special Entner-Doudoroff (ED) pathway and it has excellent industrial characteristics, including low cell mass formation, high-specific productivity,ethanol yield, notable ethanol tolerance and wide pH range, a relatively small genome size. In this study, the genome sequences of NRRL B-14023 and NRRL B-12526 were sequenced and compared with other strains to explore their evolutionary relationships and the genetic basis of Z. mobilis. The comparative genomic analyses revealed that the 8 strains share a conserved core chromosomal backbone. ZM4, NRRL B-12526, NRRL B-14023, NCIMB 11163 and NRRL B-1960 share 98% sequence identity across the whole genome sequences. Highly similar plasmids and CRISPR repeats were detected in these strains. A whole-genome phylogenetic tree of the 8 strains indicated that NRRL B-12526, NRRL B-14023 and ATCC 10988 had a close evolutionary relationship with the strain ZM4. Furthermore, strains ATCC29191 and ATCC29192 had distinctive CRISPR with a far distant relationship. The size of the pan-genome was 1945 genes, including 1428 core genes and 517 accessory genes. The genomes of Z. mobilis were highly conserved; particularly strains ZM4, NRRL B-12526, NRRL B-14023, NCIMB 11163 and NRRL B-1960 had a close genomic relationship. This comparative study of Z. mobilis presents a foundation for future functional analyses and applications.
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18
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Abstract
As masters of genome-wide regulation, miRNAs represent a key component in the complex architecture of cellular processes. Over the last decade, it has become increasingly apparent that miRNAs have many important roles in the development of disease and cancer. Recently, however, their role in viral and bacterial gene regulation as well as host gene regulation during disease progression has become a field of interest. Due to their small size, miRNAs are the ideal mechanism for bacteria and viruses that have limited room in their genomes, as a single miRNA can target up to ~30 genes. Currently, only a limited number of miRNA and miRNA-like RNAs have been found in bacteria and viruses, a number that is sure to increase rapidly in the future. The interactions of these small noncoding RNAs in such primitive species have wide-reaching effects, from increasing viral and bacterial proliferation, better responses to stress, increased virulence, to manipulation of host immune responses to provide a more ideal environment for these pathogens to thrive. Here, we explore those roles to obtain a better grasp of just how complicated disease truly is.
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19
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One-Step piggyBac Transposon-Based CRISPR/Cas9 Activation of Multiple Genes. MOLECULAR THERAPY-NUCLEIC ACIDS 2017; 8:64-76. [PMID: 28918057 PMCID: PMC5485764 DOI: 10.1016/j.omtn.2017.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Revised: 06/09/2017] [Accepted: 06/10/2017] [Indexed: 11/26/2022]
Abstract
Neural cell fate is determined by a tightly controlled transcription regulatory network during development. The ability to manipulate the expression of multiple transcription factors simultaneously is required to delineate the complex picture of neural cell development. Because of the limited carrying capacity of the commonly used viral vectors, such as lentiviral or retroviral vectors, it is often challenging to perform perturbation experiments on multiple transcription factors. Here we have developed a piggyBac (PB) transposon-based CRISPR activation (CRISPRa) all-in-one system, which allows for simultaneous and stable endogenous transactivation of multiple transcription factors and long non-coding RNAs. As a proof of principle, we showed that the PB-CRISPRa system could accelerate the differentiation of human induced pluripotent stem cells into neurons and astrocytes by triggering endogenous expression of different sets of transcription factors. The PB-CRISPRa system has the potential to become a convenient and robust tool in neuroscience, which can meet the needs of a variety of in vitro and in vivo gain-of-function applications.
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20
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Peng R, Xu Y, Zhu T, Li N, Qi J, Chai Y, Wu M, Zhang X, Shi Y, Wang P, Wang J, Gao N, Gao GF. Alternate binding modes of anti-CRISPR viral suppressors AcrF1/2 to Csy surveillance complex revealed by cryo-EM structures. Cell Res 2017; 27:853-864. [PMID: 28574055 DOI: 10.1038/cr.2017.79] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 05/07/2017] [Accepted: 05/08/2017] [Indexed: 12/11/2022] Open
Abstract
Bacteriophages encode anti-CRISPR suppressors to counteract the CRISPR/Cas immunity of their bacterial hosts, thus facilitating their survival and replication. Previous studies have shown that two phage-encoded anti-CRISPR proteins, AcrF1 and AcrF2, suppress the type I-F CRISPR/Cas system of Pseudomonas aeruginosa by preventing target DNA recognition by the Csy surveillance complex, but the precise underlying mechanism was unknown. Here we present the structure of AcrF1/2 bound to the Csy complex determined by cryo-EM single-particle reconstruction. By structural analysis, we found that AcrF1 inhibits target DNA recognition of the Csy complex by interfering with base pairing between the DNA target strand and crRNA spacer. In addition, multiple copies of AcrF1 bind to the Csy complex with different modes when working individually or cooperating with AcrF2, which might exclude target DNA binding through different mechanisms. Together with previous reports, we provide a comprehensive working scenario for the two anti-CRISPR suppressors, AcrF1 and AcrF2, which silence CRISPR/Cas immunity by targeting the Csy surveillance complex.
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Affiliation(s)
- Ruchao Peng
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 101408, China
| | - Ying Xu
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Tengfei Zhu
- University of Chinese Academy of Sciences, Beijing 101408, China.,Research Network of Immunity and Health (RNIH), Beijing Institute of Life Science, Chinese Academy of Sciences, Beijing 100101, China
| | - Ningning Li
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 101408, China
| | - Yan Chai
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Min Wu
- Department of Biomedical Sciences, School of Medicine and Health Sciences, University of North Dakota, Grand Forks, ND 58203, USA
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yi Shi
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 101408, China.,Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, Guangdong 518112, China.,Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China
| | - Peiyi Wang
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Jiawei Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Ning Gao
- State Key Laboratory of Membrane Biology, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China
| | - George Fu Gao
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 101408, China.,Research Network of Immunity and Health (RNIH), Beijing Institute of Life Science, Chinese Academy of Sciences, Beijing 100101, China.,Shenzhen Key Laboratory of Pathogen and Immunity, Shenzhen Third People's Hospital, Shenzhen, Guangdong 518112, China.,Center for Influenza Research and Early-warning (CASCIRE), Chinese Academy of Sciences, Beijing 100101, China.,National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention (China CDC), Beijing 102206, China
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21
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Bethke J, Avendaño-Herrera R. Comparative genome analysis of two Streptococcus phocae subspecies provides novel insights into pathogenicity. Mar Genomics 2017; 31:53-61. [DOI: 10.1016/j.margen.2016.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/28/2016] [Accepted: 09/29/2016] [Indexed: 10/20/2022]
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22
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Patel S. Drivers of bacterial genomes plasticity and roles they play in pathogen virulence, persistence and drug resistance. INFECTION GENETICS AND EVOLUTION 2016; 45:151-164. [DOI: 10.1016/j.meegid.2016.08.030] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 08/26/2016] [Accepted: 08/27/2016] [Indexed: 12/11/2022]
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23
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Ang MY, Dutta A, Wee WY, Dymock D, Paterson IC, Choo SW. Comparative Genome Analysis of Fusobacterium nucleatum. Genome Biol Evol 2016; 8:2928-2938. [PMID: 27540086 PMCID: PMC5630926 DOI: 10.1093/gbe/evw199] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Fusobacterium nucleatum is considered to be a key oral bacterium in recruiting periodontal pathogens into subgingival dental plaque. Currently F. nucleatum can be subdivided into five subspecies. Our previous genome analysis of F. nucleatum W1481 (referred to hereafter as W1481), isolated from an 8-mm periodontal pocket in a patient with chronic periodontitis, suggested the possibility of a new subspecies. To further investigate the biology and relationships of this possible subspecies with other known subspecies, we performed comparative analysis between W1481 and 35 genome sequences represented by the five known Fusobacterium subspecies. Our analyses suggest that W1481 is most likely a new F. nucleatum subspecies, supported by evidence from phylogenetic analyses and maximal unique match indices (MUMi). Interestingly, we found a horizontally transferred W1481-specific genomic island harboring the tripartite ATP-independent (TRAP)-like transporter genes, suggesting this bacterium might have a high-affinity transport system for the C4-dicarboxylates malate, succinate, and fumarate. Moreover, we found virulence genes in the W1481 genome that may provide a strong defense mechanism which might enable it to colonize and survive within the host by evading immune surveillance. This comparative study provides better understanding of F. nucleatum and the basis for future functional work on this important pathogen.
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Affiliation(s)
- Mia Yang Ang
- Genome Informatics Research Laboratory, Centre for Research in Biotechnology for Agriculture (CEBAR), High Impact Research Building, University of Malaya, Kuala Lumpur, Malaysia Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia
| | - Avirup Dutta
- Genome Informatics Research Laboratory, Centre for Research in Biotechnology for Agriculture (CEBAR), High Impact Research Building, University of Malaya, Kuala Lumpur, Malaysia
| | - Wei Yee Wee
- Genome Informatics Research Laboratory, Centre for Research in Biotechnology for Agriculture (CEBAR), High Impact Research Building, University of Malaya, Kuala Lumpur, Malaysia Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia
| | - David Dymock
- School of Oral & Dental Sciences, University of Bristol, Bristol, United Kingdom
| | - Ian C Paterson
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia Oral Cancer Research and Coordinating Centre (OCRCC), Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia
| | - Siew Woh Choo
- Genome Informatics Research Laboratory, Centre for Research in Biotechnology for Agriculture (CEBAR), High Impact Research Building, University of Malaya, Kuala Lumpur, Malaysia Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia Genome Solutions Sdn Bhd, Suite 8, Innovation Incubator UM, Level 5, Research Management & Innovation Complex, University of Malaya, Kuala Lumpur, Malaysia
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Lange A, Beier S, Steimle A, Autenrieth IB, Huson DH, Frick JS. Extensive Mobilome-Driven Genome Diversification in Mouse Gut-Associated Bacteroides vulgatus mpk. Genome Biol Evol 2016; 8:1197-207. [PMID: 27071651 PMCID: PMC4860699 DOI: 10.1093/gbe/evw070] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Like many other Bacteroides species, Bacteroides vulgatus strain mpk, a mouse fecal isolate which was shown to promote intestinal homeostasis, utilizes a variety of mobile elements for genome evolution. Based on sequences collected by Pacific Biosciences SMRT sequencing technology, we discuss the challenges of assembling and studying a bacterial genome of high plasticity. Additionally, we conducted comparative genomics comparing this commensal strain with the B. vulgatus type strain ATCC 8482 as well as multiple other Bacteroides and Parabacteroides strains to reveal the most important differences and identify the unique features of B. vulgatus mpk. The genome of B. vulgatus mpk harbors a large and diverse set of mobile element proteins compared with other sequenced Bacteroides strains. We found evidence of a number of different horizontal gene transfer events and a genome landscape that has been extensively altered by different mobilization events. A CRISPR/Cas system could be identified that provides a possible mechanism for preventing the integration of invading external DNA. We propose that the high genome plasticity and the introduced genome instabilities of B. vulgatus mpk arising from the various mobilization events might play an important role not only in its adaptation to the challenging intestinal environment in general, but also in its ability to interact with the gut microbiota.
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Affiliation(s)
- Anna Lange
- Interfacultary Institute for Microbiology and Infection Medicine, Department for Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Sina Beier
- Algorithms in Bioinformatics, ZBIT Center for Bioinformatics, University of Tübingen, Tübingen, Germany
| | - Alex Steimle
- Interfacultary Institute for Microbiology and Infection Medicine, Department for Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Ingo B Autenrieth
- Interfacultary Institute for Microbiology and Infection Medicine, Department for Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
| | - Daniel H Huson
- Algorithms in Bioinformatics, ZBIT Center for Bioinformatics, University of Tübingen, Tübingen, Germany
| | - Julia-Stefanie Frick
- Interfacultary Institute for Microbiology and Infection Medicine, Department for Medical Microbiology and Hygiene, University of Tübingen, Tübingen, Germany
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Abstract
The clustered regularly interspaced short palindromic repeats (CRISPR)-Cas (CRISPR-associated proteins) is a prokaryotic adaptive immune system that is represented in most archaea and many bacteria. Among the currently known prokaryotic defense systems, the CRISPR-Cas genomic loci show unprecedented complexity and diversity. Classification of CRISPR-Cas variants that would capture their evolutionary relationships to the maximum possible extent is essential for comparative genomic and functional characterization of this theoretically and practically important system of adaptive immunity. To this end, a multipronged approach has been developed that combines phylogenetic analysis of the conserved Cas proteins with comparison of gene repertoires and arrangements in CRISPR-Cas loci. This approach led to the current classification of CRISPR-Cas systems into three distinct types and ten subtypes for each of which signature genes have been identified. Comparative genomic analysis of the CRISPR-Cas systems in new archaeal and bacterial genomes performed over the 3 years elapsed since the development of this classification makes it clear that new types and subtypes of CRISPR-Cas need to be introduced. Moreover, this classification system captures only part of the complexity of CRISPR-Cas organization and evolution, due to the intrinsic modularity and evolutionary mobility of these immunity systems, resulting in numerous recombinant variants. Moreover, most of the cas genes evolve rapidly, complicating the family assignment for many Cas proteins and the use of family profiles for the recognition of CRISPR-Cas subtype signatures. Further progress in the comparative analysis of CRISPR-Cas systems requires integration of the most sensitive sequence comparison tools, protein structure comparison, and refined approaches for comparison of gene neighborhoods.
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26
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Maxwell KL. Phages Fight Back: Inactivation of the CRISPR-Cas Bacterial Immune System by Anti-CRISPR Proteins. PLoS Pathog 2016; 12:e1005282. [PMID: 26741979 PMCID: PMC4704812 DOI: 10.1371/journal.ppat.1005282] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Affiliation(s)
- Karen L Maxwell
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
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27
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Bondy-Denomy J, Garcia B, Strum S, Du M, Rollins MF, Hidalgo-Reyes Y, Wiedenheft B, Maxwell KL, Davidson AR. Multiple mechanisms for CRISPR-Cas inhibition by anti-CRISPR proteins. Nature 2015; 526:136-9. [PMID: 26416740 DOI: 10.1038/nature15254] [Citation(s) in RCA: 253] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Accepted: 07/29/2015] [Indexed: 12/22/2022]
Abstract
The battle for survival between bacteria and the viruses that infect them (phages) has led to the evolution of many bacterial defence systems and phage-encoded antagonists of these systems. Clustered regularly interspaced short palindromic repeats (CRISPR) and the CRISPR-associated (cas) genes comprise an adaptive immune system that is one of the most widespread means by which bacteria defend themselves against phages. We identified the first examples of proteins produced by phages that inhibit a CRISPR-Cas system. Here we performed biochemical and in vivo investigations of three of these anti-CRISPR proteins, and show that each inhibits CRISPR-Cas activity through a distinct mechanism. Two block the DNA-binding activity of the CRISPR-Cas complex, yet do this by interacting with different protein subunits, and using steric or non-steric modes of inhibition. The third anti-CRISPR protein operates by binding to the Cas3 helicase-nuclease and preventing its recruitment to the DNA-bound CRISPR-Cas complex. In vivo, this anti-CRISPR can convert the CRISPR-Cas system into a transcriptional repressor, providing the first example-to our knowledge-of modulation of CRISPR-Cas activity by a protein interactor. The diverse sequences and mechanisms of action of these anti-CRISPR proteins imply an independent evolution, and foreshadow the existence of other means by which proteins may alter CRISPR-Cas function.
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Affiliation(s)
- Joseph Bondy-Denomy
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Bianca Garcia
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Scott Strum
- Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Mingjian Du
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - MaryClare F Rollins
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana 59717, USA
| | - Yurima Hidalgo-Reyes
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Blake Wiedenheft
- Department of Microbiology and Immunology, Montana State University, Bozeman, Montana 59717, USA
| | - Karen L Maxwell
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Alan R Davidson
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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Mechanisms of Evolutionary Innovation Point to Genetic Control Logic as the Key Difference Between Prokaryotes and Eukaryotes. J Mol Evol 2015. [PMID: 26208881 DOI: 10.1007/s00239-015-9688-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The evolution of life from the simplest, original form to complex, intelligent animal life occurred through a number of key innovations. Here we present a new tool to analyze these key innovations by proposing that the process of evolutionary innovation may follow one of three underlying processes, namely a Random Walk, a Critical Path, or a Many Paths process, and in some instances may also constitute a "Pull-up the Ladder" event. Our analysis is based on the occurrence of function in modern biology, rather than specific structure or mechanism. A function in modern biology may be classified in this way either on the basis of its evolution or the basis of its modern mechanism. Characterizing key innovations in this way helps identify the likelihood that an innovation could arise. In this paper, we describe the classification, and methods to classify functional features of modern organisms into these three classes based on the analysis of how a function is implemented in modern biology. We present the application of our categorization to the evolution of eukaryotic gene control. We use this approach to support the argument that there are few, and possibly no basic chemical differences between the functional constituents of the machinery of gene control between eukaryotes, bacteria and archaea. This suggests that the difference between eukaryotes and prokaryotes that allows the former to develop the complex genetic architecture seen in animals and plants is something other than their chemistry. We tentatively identify the difference as a difference in control logic, that prokaryotic genes are by default 'on' and eukaryotic genes are by default 'off.' The Many Paths evolutionary process suggests that, from a 'default off' starting point, the evolution of the genetic complexity of higher eukaryotes is a high probability event.
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Fiebig A, Loof TG, Babbar A, Itzek A, Koehorst JJ, Schaap PJ, Nitsche-Schmitz DP. Comparative genomics of Streptococcus pyogenes M1 isolates differing in virulence and propensity to cause systemic infection in mice. Int J Med Microbiol 2015; 305:532-43. [PMID: 26129624 DOI: 10.1016/j.ijmm.2015.06.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 06/15/2015] [Accepted: 06/19/2015] [Indexed: 12/14/2022] Open
Abstract
Streptococcus pyogenes serotype M1 is a frequent cause of severe infections in humans. Some M1 isolates are pathogenic in mice and used in studies on infection pathogenesis. We observed marked differences in murine infections caused by M1 strain SF370, 5448, 5448AP or AP1 which prompted us to sequence the whole genome of isolates 5448 and AP1 for comparative analysis. Strain 5448 is known to acquire inactivating mutations in the CovRS two-component system during mouse infection, producing hypervirulent progeny such as 5448AP. Isolates AP1 and 5448AP, more than 5448, caused disseminating infections that became systemic and lethal. SF370 was not pathogenic. Phages caused gross genetic differences and increased the gene content of AP1 by 8% as compared to 5448 and SF370. Each of six examined M1 genomes contained two CRISPR-Cas systems. Phage insertion destroyed a type II CRISPR-Cas system in AP1 and other strains of serotypes M1, M3, M6 and M24, but not in M1 strains 5448, SF370, MGAS5005, A20 or M1 476. A resulting impaired defence against invading genetic elements could have led to the wealth of phages in AP1. AP1 lacks genetic features of the MGAS5005-like clonal complex including the streptodornase that drives selection for hypervirulent clones with inactivated CovRS system. Still, inactivating mutations in covS were a common genetic feature of AP1 and the MGAS5005-like isolate 5448AP. Abolished expression of the cysteine proteinase SpeB, due to CovRS inactivation could be a common cause for hypervirulence of the two isolates. Moreover, an additional protein H-coding gene and a mutation in the regulator gene rofA distinguished AP1 form other M1 isolates. In conclusion, hypervirulence of S. pyogenes M1 in mice is not limited to the MGAS5005-like genotype.
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Affiliation(s)
- Anne Fiebig
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Torsten G Loof
- Infection Immunology Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Anshu Babbar
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Andreas Itzek
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Jasper J Koehorst
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research Centre, Wageningen, the Netherlands
| | - Peter J Schaap
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research Centre, Wageningen, the Netherlands
| | - D Patric Nitsche-Schmitz
- Microbial Interactions and Processes Research Group, Helmholtz Centre for Infection Research, Braunschweig, Germany.
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30
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Pliatsika V, Rigoutsos I. "Off-Spotter": very fast and exhaustive enumeration of genomic lookalikes for designing CRISPR/Cas guide RNAs. Biol Direct 2015; 10:4. [PMID: 25630343 PMCID: PMC4326336 DOI: 10.1186/s13062-015-0035-z] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2014] [Accepted: 01/09/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND CRISPR/Cas (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated nucleases) is a powerful component of the prokaryotic immune system that has been adapted for targeted genetic engineering in higher organisms. A key element of CRISPR/Cas is the "guide" RNA (gRNA) that is ~20 nucleotides (nts) in length and designed to be complementary to the intended target site. An integral requirement of the CRISPR/Cas system is that the target site be followed by a protospacer adjacent motif (PAM). Care needs to be exercised during gRNA design to avoid unintended ("off-target") interactions. RESULTS We designed and implemented the Off-Spotter algorithm to assist with the design of optimal gRNAs. When presented with a candidate gRNA sequence and a PAM, Off-Spotter quickly and exhaustively identifies all genomic sites that satisfy the PAM constraint and are identical or nearly-identical to the provided gRNA. Off-Spotter achieves its extreme performance through purely algorithmic means and not through hardware accelerators such as graphical processing units (GPUs). Off-Spotter also allows the user to identify on-the-fly how many and which nucleotides of the gRNA comprise the "seed". Off-Spotter's output includes a histogram showing the number of potential off-targets as a function of the number of mismatches. The output also includes for each potential off-target the site's genomic location, a human genome browser hyperlink to the corresponding location, genomic annotation in the vicinity of the off-target, GC content, etc. CONCLUSION Off-Spotter is very fast and flexible and can help in the design of optimal gRNAs by providing several PAM choices, a run-time definition of the seed and of the allowed number of mismatches, and a flexible output interface that allows sorting of the results, optional viewing/hiding of columns, etc. A key element of Off-Spotter is that it does not have a rigid definition of the seed: instead, the user can declare both the seed's location and extent on-the-fly. We expect that this flexibility in combination with Off-Spotter's speed and richly annotated output will enable experimenters to interactively and quickly explore different scenarios and gRNA possibilities.
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Affiliation(s)
- Venetia Pliatsika
- Computational Medicine Center, Jefferson Alumni Hall, #M81, Sidney Kimmel Medical College at Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107 USA
| | - Isidore Rigoutsos
- Computational Medicine Center, Jefferson Alumni Hall, #M81, Sidney Kimmel Medical College at Thomas Jefferson University, 1020 Locust Street, Philadelphia, PA 19107 USA
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31
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Raftis EJ, Forde BM, Claesson MJ, O'Toole PW. Unusual genome complexity in Lactobacillus salivarius JCM1046. BMC Genomics 2014; 15:771. [PMID: 25201645 PMCID: PMC4165912 DOI: 10.1186/1471-2164-15-771] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 08/26/2014] [Indexed: 12/31/2022] Open
Abstract
Background Lactobacillus salivarius strains are increasingly being exploited for their probiotic properties in humans and animals. Dissemination of antibiotic resistance genes among species with food or probiotic-association is undesirable and is often mediated by plasmids or integrative and conjugative elements. L. salivarius strains typically have multireplicon genomes including circular megaplasmids that encode strain-specific traits for intestinal survival and probiotic activity. Linear plasmids are less common in lactobacilli and show a very limited distribution in L. salivarius. Here we present experimental evidence that supports an unusually complex multireplicon genome structure in the porcine isolate L. salivarius JCM1046. Results JCM1046 harbours a 1.83 Mb chromosome, and four plasmids which constitute 20% of the genome. In addition to the known 219 kb repA-type megaplasmid pMP1046A, we identified and experimentally validated the topology of three additional replicons, the circular pMP1046B (129 kb), a linear plasmid pLMP1046 (101 kb) and pCTN1046 (33 kb) harbouring a conjugative transposon. pMP1046B harbours both plasmid-associated replication genes and paralogues of chromosomally encoded housekeeping and information-processing related genes, thus qualifying it as a putative chromid. pLMP1046 shares limited sequence homology or gene synteny with other L. salivarius plasmids, and its putative replication-associated protein is homologous to the RepA/E proteins found in the large circular megaplasmids of L. salivarius. Plasmid pCTN1046 harbours a single copy of an integrated conjugative transposon (Tn6224) which appears to be functionally intact and includes the tetracycline resistance gene tetM. Conclusion Experimental validation of sequence assemblies and plasmid topology resolved the complex genome architecture of L. salivarius JCM1046. A high-coverage draft genome sequence would not have elucidated the genome complexity in this strain. Given the expanding use of L. salivarius as a probiotic, it is important to determine the genotypic and phenotypic organization of L. salivarius strains. The identification of Tn6224-like elements in this species has implications for strain selection for probiotic applications. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-771) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | - Paul W O'Toole
- School of Microbiology University College Cork, Cork, Ireland.
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32
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Huo Y, Nam KH, Ding F, Lee H, Wu L, Xiao Y, Farchione MD, Zhou S, Rajashankar K, Kurinov I, Zhang R, Ke A. Structures of CRISPR Cas3 offer mechanistic insights into Cascade-activated DNA unwinding and degradation. Nat Struct Mol Biol 2014. [PMID: 25132177 DOI: 10.1038/nsmb.2875.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CRISPR drives prokaryotic adaptation to invasive nucleic acids such as phages and plasmids, using an RNA-mediated interference mechanism. Interference in type I CRISPR-Cas systems requires a targeting Cascade complex and a degradation machine, Cas3, which contains both nuclease and helicase activities. Here we report the crystal structures of Thermobifida fusca Cas3 bound to single-stranded (ss) DNA substrate and show that it is an obligate 3'-to-5' ssDNase that preferentially accepts substrate directly from the helicase moiety. Conserved residues in the HD-type nuclease coordinate two irons for ssDNA cleavage. We demonstrate ATP coordination and conformational flexibility of the SF2-type helicase domain. Cas3 is specifically guided toward Cascade-bound target DNA by a PAM sequence, through physical interactions with both the nontarget substrate strand and the CasA protein. The sequence of recognition events ensures well-controlled DNA targeting and degradation of foreign DNA by Cascade and Cas3.
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Affiliation(s)
- Yanwu Huo
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2]
| | - Ki Hyun Nam
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2] [3]
| | - Fang Ding
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2]
| | - Heejin Lee
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2]
| | - Lijie Wu
- Institute of Biochemistry and Cell Biology, Shanghai, China
| | - Yibei Xiao
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | - M Daniel Farchione
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | - Sharleen Zhou
- Howard Hughes Medical Institute, Mass Spectrometry Laboratory, University of California, Berkeley, Berkeley, California, USA
| | - Kanagalaghatta Rajashankar
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, USA
| | - Igor Kurinov
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, USA
| | | | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
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Huo Y, Nam KH, Ding F, Lee H, Wu L, Xiao Y, Farchione MD, Zhou S, Rajashankar K, Kurinov I, Zhang R, Ke A. Structures of CRISPR Cas3 offer mechanistic insights into Cascade-activated DNA unwinding and degradation. Nat Struct Mol Biol 2014; 21:771-7. [PMID: 25132177 PMCID: PMC4156918 DOI: 10.1038/nsmb.2875] [Citation(s) in RCA: 139] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/18/2014] [Indexed: 12/19/2022]
Abstract
CRISPR drives prokaryotic adaptation to invasive nucleic acids such as phages and plasmids using an RNA-mediated interference mechanism. Interference in Type I CRISPR-Cas systems requires a targeting Cascade complex and a degradation machine Cas3, which contains both nuclease and helicase activities. Here we report the crystal structures of Cas3 bound to ss-DNA substrate and show that it is an obligated 3′-to-5′ ss-DNase preferentially accepting substrate directly from the helicase moiety. Conserved residues in the HD-type nuclease coordinate two irons for ss-DNA cleavage. ATP coordination and conformational flexibility are revealed for the SF2-type helicase moiety. Cas3 is specifically guided towards Cascade-bound target DNA with a correct PAM sequence, through physical interactions to both the non-target substrate strand and the CasA protein. The cascade of recognition events ensures a well-controlled DNA targeting and degradation of alien DNA by Cascade and Cas3.
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Affiliation(s)
- Yanwu Huo
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2]
| | - Ki Hyun Nam
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2] [3]
| | - Fang Ding
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2]
| | - Heejin Lee
- 1] Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA. [2]
| | - Lijie Wu
- Institute of Biochemistry and Cell Biology, Shanghai, China
| | - Yibei Xiao
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | - M Daniel Farchione
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
| | - Sharleen Zhou
- Howard Hughes Medical Institute, Mass Spectrometry Laboratory, University of California, Berkeley, Berkeley, California, USA
| | - Kanagalaghatta Rajashankar
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, USA
| | - Igor Kurinov
- Northeastern Collaborative Access Team and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois, USA
| | | | - Ailong Ke
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, USA
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Carte J, Christopher RT, Smith JT, Olson S, Barrangou R, Moineau S, Glover CVC, Graveley BR, Terns RM, Terns MP. The three major types of CRISPR-Cas systems function independently in CRISPR RNA biogenesis in Streptococcus thermophilus. Mol Microbiol 2014; 93:98-112. [PMID: 24811454 PMCID: PMC4095994 DOI: 10.1111/mmi.12644] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2014] [Indexed: 12/25/2022]
Abstract
CRISPR-Cas systems are small RNA-based immune systems that protect prokaryotes from invaders such as viruses and plasmids. We have investigated the features and biogenesis of the CRISPR (cr)RNAs in Streptococcus thermophilus (Sth) strain DGCC7710, which possesses four different CRISPR-Cas systems including representatives from the three major types of CRISPR-Cas systems. Our results indicate that the crRNAs from each CRISPR locus are specifically processed into divergent crRNA species by Cas proteins (and non-coding RNAs) associated with the respective locus. We find that the Csm Type III-A and Cse Type I-E crRNAs are specifically processed by Cas6 and Cse3 (Cas6e), respectively, and retain an 8-nucleotide CRISPR repeat sequence tag 5' of the invader-targeting sequence. The Cse Type I-E crRNAs also retain a 21-nucleotide 3' repeat tag. The crRNAs from the two Csn Type II-A systems in Sth consist of a 5'-truncated targeting sequence and a 3' tag; however, these are distinct in size between the two. Moreover, the Csn1 (Cas9) protein associated with one Csn locus functions specifically in the production of crRNAs from that locus. Our findings indicate that multiple CRISPR-Cas systems can function independently in crRNA biogenesis within a given organism - an important consideration in engineering coexisting CRISPR-Cas pathways.
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Affiliation(s)
- Jason Carte
- Department of Biochemistry and Molecular Biology, University of Georgia Athens, GA 30602
| | - Ross T. Christopher
- Department of Biochemistry and Molecular Biology, University of Georgia Athens, GA 30602
| | - Justin T. Smith
- Department of Biochemistry and Molecular Biology, University of Georgia Athens, GA 30602
| | - Sara Olson
- Department of Genetics and Developmental Biology, Institute for Systems Genomics, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030
| | - Rodolphe Barrangou
- Department of Food, Bioprocessing and Nutrition Sciences, North Carolina State University, Raleigh, NC, 27695
| | - Sylvain Moineau
- Département de Biochimie, de Microbiologie et de Bio-informatique, Faculté des Sciences et de Génie, Groupe de Recherche en Écologie Buccale, Faculté de Médecine Dentaire, Université Laval, Québec City, Quebec, Canada G1V 0A6
| | - Claiborne V. C. Glover
- Department of Biochemistry and Molecular Biology, University of Georgia Athens, GA 30602
| | - Brenton R. Graveley
- Department of Genetics and Developmental Biology, Institute for Systems Genomics, University of Connecticut Health Center, 400 Farmington Avenue, Farmington, CT 06030
| | - Rebecca M. Terns
- Department of Biochemistry and Molecular Biology, University of Georgia Athens, GA 30602
| | - Michael P. Terns
- Department of Biochemistry and Molecular Biology, University of Georgia Athens, GA 30602
- Departments of Genetics and Microbiology, University of Georgia Athens, GA 30602
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35
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Carte J, Christopher RT, Smith JT, Olson S, Barrangou R, Moineau S, Glover CVC, Graveley BR, Terns RM, Terns MP. The three major types of CRISPR-Cas systems function independently in CRISPR RNA biogenesis in Streptococcus thermophilus. Mol Microbiol 2014. [PMID: 24811454 DOI: 10.1111/mmi.12644.the] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
CRISPR-Cas systems are small RNA-based immune systems that protect prokaryotes from invaders such as viruses and plasmids. We have investigated the features and biogenesis of the CRISPR (cr)RNAs in Streptococcus thermophilus (Sth) strain DGCC7710, which possesses four different CRISPR-Cas systems including representatives from the three major types of CRISPR-Cas systems. Our results indicate that the crRNAs from each CRISPR locus are specifically processed into divergent crRNA species by Cas proteins (and non-coding RNAs) associated with the respective locus. We find that the Csm Type III-A and Cse Type I-E crRNAs are specifically processed by Cas6 and Cse3 (Cas6e), respectively, and retain an 8-nucleotide CRISPR repeat sequence tag 5' of the invader-targeting sequence. The Cse Type I-E crRNAs also retain a 21-nucleotide 3' repeat tag. The crRNAs from the two Csn Type II-A systems in Sth consist of a 5'-truncated targeting sequence and a 3' tag; however, these are distinct in size between the two. Moreover, the Csn1 (Cas9) protein associated with one Csn locus functions specifically in the production of crRNAs from that locus. Our findings indicate that multiple CRISPR-Cas systems can function independently in crRNA biogenesis within a given organism - an important consideration in engineering coexisting CRISPR-Cas pathways.
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Affiliation(s)
- Jason Carte
- Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, 30602, USA
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Abstract
The ability to sequence genomes and characterize their products has begun to reveal the central role for regulatory RNAs in biology, especially in complex organisms. It is now evident that the human genome contains not only protein-coding genes, but also tens of thousands of non-protein coding genes that express small and long ncRNAs (non-coding RNAs). Rapid progress in characterizing these ncRNAs has identified a diverse range of subclasses, which vary widely in size, sequence and mechanism-of-action, but share a common functional theme of regulating gene expression. ncRNAs play a crucial role in many cellular pathways, including the differentiation and development of cells and organs and, when mis-regulated, in a number of diseases. Increasing evidence suggests that these RNAs are a major area of evolutionary innovation and play an important role in determining phenotypic diversity in animals.
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Pawluk A, Bondy-Denomy J, Cheung VHW, Maxwell KL, Davidson AR. A new group of phage anti-CRISPR genes inhibits the type I-E CRISPR-Cas system of Pseudomonas aeruginosa. mBio 2014; 5:e00896. [PMID: 24736222 PMCID: PMC3993853 DOI: 10.1128/mbio.00896-14] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 03/13/2014] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems are one of the most widespread phage resistance mechanisms in prokaryotes. Our lab recently identified the first examples of phage-borne anti-CRISPR genes that encode protein inhibitors of the type I-F CRISPR-Cas system of Pseudomonas aeruginosa. A key question arising from this work was whether there are other types of anti-CRISPR genes. In the current work, we address this question by demonstrating that some of the same phages carrying type I-F anti-CRISPR genes also possess genes that mediate inhibition of the type I-E CRISPR-Cas system of P. aeruginosa. We have discovered four distinct families of these type I-E anti-CRISPR genes. These genes do not inhibit the type I-F CRISPR-Cas system of P. aeruginosa or the type I-E system of Escherichia coli. Type I-E and I-F anti-CRISPR genes are located at the same position in the genomes of a large group of related P. aeruginosa phages, yet they are found in a variety of combinations and arrangements. We have also identified functional anti-CRISPR genes within nonprophage Pseudomonas genomic regions that are likely mobile genetic elements. This work emphasizes the potential importance of anti-CRISPR genes in phage evolution and lateral gene transfer and supports the hypothesis that more undiscovered families of anti-CRISPR genes exist. Finally, we provide the first demonstration that the type I-E CRISPR-Cas system of P. aeruginosa is naturally active without genetic manipulation, which contrasts with E. coli and other previously characterized I-E systems. IMPORTANCE The CRISPR-Cas system is an adaptive immune system possessed by the majority of prokaryotic organisms to combat potentially harmful foreign genetic elements. This study reports the discovery of bacteriophage-encoded anti-CRISPR genes that mediate inhibition of a well-studied subtype of CRISPR-Cas system. The four families of anti-CRISPR genes described here, which comprise only the second group of anti-CRISPR genes to be identified, encode small proteins that bear no sequence similarity to previously studied phage or bacterial proteins. Anti-CRISPR genes represent a newly discovered and intriguing facet of the ongoing evolutionary competition between phages and their bacterial hosts.
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Affiliation(s)
- April Pawluk
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Joseph Bondy-Denomy
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Vivian H. W. Cheung
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Karen L. Maxwell
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
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Molecular mechanisms of CRISPR-mediated microbial immunity. Cell Mol Life Sci 2014; 71:449-65. [PMID: 23959171 PMCID: PMC3890593 DOI: 10.1007/s00018-013-1438-6] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/21/2013] [Accepted: 07/24/2013] [Indexed: 12/15/2022]
Abstract
Bacteriophages (phages) infect bacteria in order to replicate and burst out of the host, killing the cell, when reproduction is completed. Thus, from a bacterial perspective, phages pose a persistent lethal threat to bacterial populations. Not surprisingly, bacteria evolved multiple defense barriers to interfere with nearly every step of phage life cycles. Phages respond to this selection pressure by counter-evolving their genomes to evade bacterial resistance. The antagonistic interaction between bacteria and rapidly diversifying viruses promotes the evolution and dissemination of bacteriophage-resistance mechanisms in bacteria. Recently, an adaptive microbial immune system, named clustered regularly interspaced short palindromic repeats (CRISPR) and which provides acquired immunity against viruses and plasmids, has been identified. Unlike the restriction–modification anti-phage barrier that subjects to cleavage any foreign DNA lacking a protective methyl-tag in the target site, the CRISPR–Cas systems are invader-specific, adaptive, and heritable. In this review, we focus on the molecular mechanisms of interference/immunity provided by different CRISPR–Cas systems.
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Abstract
CRISPR (clustered regularly interspaced short palindromic repeats) together with cas (CRISPR-associated) genes form the CRISPR–Cas immune system, which provides sequence-specific adaptive immunity against foreign genetic elements in bacteria and archaea. Immunity is acquired by the integration of short stretches of invasive DNA as novel ‘spacers’ into CRISPR loci. Subsequently, these immune markers are transcribed and generate small non-coding interfering RNAs that specifically guide nucleases for sequence-specific cleavage of complementary sequences. Among the four CRISPR–Cas systems present in Streptococcus thermophilus, CRISPR1 and CRISPR3 have the ability to readily acquire new spacers following bacteriophage or plasmid exposure. In order to investigate the impact of building CRISPR-encoded immunity on the host chromosome, we determined the genome sequence of a BIM (bacteriophage-insensitive mutant) derived from the DGCC7710 model organism, after four consecutive rounds of bacteriophage challenge. As expected, active CRISPR loci evolved via polarized addition of several novel spacers following exposure to bacteriophages. Although analysis of the draft genome sequence revealed a variety of SNPs (single nucleotide polymorphisms) and INDELs (insertions/deletions), most of the in silico differences were not validated by Sanger re-sequencing. In addition, two SNPs and two small INDELs were identified and tracked in the intermediate variants. Overall, building CRISPR-encoded immunity does not significantly affect the genome, which allows the maintenance of important functional properties in isogenic CRISPR mutants. This is critical for the development and formulation of sustainable and robust next-generation starter cultures with increased industrial lifespans.
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Arslan Z, Stratmann T, Wurm R, Wagner R, Schnetz K, Pul Ü. RcsB-BglJ-mediated activation of Cascade operon does not induce the maturation of CRISPR RNAs in E. coli K12. RNA Biol 2013; 10:708-15. [PMID: 23392250 PMCID: PMC3737329 DOI: 10.4161/rna.23765] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 01/23/2013] [Accepted: 01/24/2013] [Indexed: 11/19/2022] Open
Abstract
Prokaryotic immunity against foreign nucleic acids mediated by clustered, regularly interspaced, short palindromic repeats (CRISPR) depends on the expression of the CRISPR-associated (Cas) proteins and the formation of small CRISPR RNAs (crRNAs). The crRNA-loaded Cas ribonucleoprotein complexes convey the specific recognition and inactivation of target nucleic acids. In E. coli K12, the maturation of crRNAs and the interference with target DNA is performed by the Cascade complex. The transcription of the Cascade operon is tightly repressed through H-NS-dependent inhibition of the Pcas promoter. Elevated levels of the LysR-type regulator LeuO induce the Pcas promoter and concomitantly activate the CRISPR-mediated immunity against phages. Here, we show that the Pcas promoter can also be induced by constitutive expression of the regulator BglJ. This activation is LeuO-dependent as heterodimers of BglJ and RcsB activate leuO transcription. Each transcription factor, LeuO or BglJ, induced the transcription of the Cascade genes to comparable amounts. However, the maturation of the crRNAs was activated in LeuO but not in BglJ-expressing cells. Studies on CRISPR promoter activities, transcript stabilities, crRNA processing and Cascade protein levels were performed to answer the question why crRNA maturation is defective in BglJ-expressing cells. Our results demonstrate that the activation of Cascade gene transcription is necessary but not sufficient to turn on the CRISPR-mediated immunity and suggest a more complex regulation of the type I-E CRISPR-Cas system in E. coli.
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Affiliation(s)
- Zihni Arslan
- Molecular Biology of Bacteria; Heinrich-Heine University; Düsseldorf, Germany
| | | | - Reinhild Wurm
- Molecular Biology of Bacteria; Heinrich-Heine University; Düsseldorf, Germany
| | - Rolf Wagner
- Molecular Biology of Bacteria; Heinrich-Heine University; Düsseldorf, Germany
| | - Karin Schnetz
- Institute for Genetics; University of Cologne; Cologne, Germany
| | - Ümit Pul
- Molecular Biology of Bacteria; Heinrich-Heine University; Düsseldorf, Germany
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Westra ER, Swarts DC, Staals RHJ, Jore MM, Brouns SJJ, van der Oost J. The CRISPRs, they are a-changin': how prokaryotes generate adaptive immunity. Annu Rev Genet 2013; 46:311-39. [PMID: 23145983 DOI: 10.1146/annurev-genet-110711-155447] [Citation(s) in RCA: 203] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
All organisms need to continuously adapt to changes in their environment. Through horizontal gene transfer, bacteria and archaea can rapidly acquire new traits that may contribute to their survival. However, because new DNA may also cause damage, removal of imported DNA and protection against selfish invading DNA elements are also important. Hence, there should be a delicate balance between DNA uptake and DNA degradation. Here, we describe prokaryotic antiviral defense systems, such as receptor masking or mutagenesis, blocking of phage DNA injection, restriction/modification, and abortive infection. The main focus of this review is on CRISPR (clustered regularly interspaced short palindromic repeats)/Cas (CRISPR-associated), a prokaryotic adaptive immune system. Since its recent discovery, our biochemical understanding of this defense system has made a major leap forward. Three highly diverse CRISPR/Cas types exist that display major structural and functional differences in their mode of generating resistance against invading nucleic acids. Because several excellent recent reviews cover all CRISPR subtypes, we mainly focus on a detailed description of the type I-E CRISPR/Cas system of the model bacterium Escherichia coli K12.
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Affiliation(s)
- Edze R Westra
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, 6703 HB Wageningen, The Netherlands.
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Chylinski K, Le Rhun A, Charpentier E. The tracrRNA and Cas9 families of type II CRISPR-Cas immunity systems. RNA Biol 2013; 10:726-37. [PMID: 23563642 PMCID: PMC3737331 DOI: 10.4161/rna.24321] [Citation(s) in RCA: 263] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
CRISPR-Cas is a rapidly evolving RNA-mediated adaptive immune system that protects bacteria and archaea against mobile genetic elements. The system relies on the activity of short mature CRISPR RNAs (crRNAs) that guide Cas protein(s) to silence invading nucleic acids. A set of CRISPR-Cas, type II, requires a trans-activating small RNA, tracrRNA, for maturation of precursor crRNA (pre-crRNA) and interference with invading sequences. Following co-processing of tracrRNA and pre-crRNA by RNase III, dual-tracrRNA:crRNA guides the CRISPR-associated endonuclease Cas9 (Csn1) to cleave site-specifically cognate target DNA. Here, we screened available genomes for type II CRISPR-Cas loci by searching for Cas9 orthologs. We analyzed 75 representative loci, and for 56 of them we predicted novel tracrRNA orthologs. Our analysis demonstrates a high diversity in cas operon architecture and position of the tracrRNA gene within CRISPR-Cas loci. We observed a correlation between locus heterogeneity and Cas9 sequence diversity, resulting in the identification of various type II CRISPR-Cas subgroups. We validated the expression and co-processing of predicted tracrRNAs and pre-crRNAs by RNA sequencing in five bacterial species. This study reveals tracrRNA family as an atypical, small RNA family with no obvious conservation of structure, sequence or localization within type II CRISPR-Cas loci. The tracrRNA family is however characterized by the conserved feature to base-pair to cognate pre-crRNA repeats, an essential function for crRNA maturation and DNA silencing by dual-RNA:Cas9. The large panel of tracrRNA and Cas9 ortholog sequences should constitute a useful database to improve the design of RNA-programmable Cas9 as genome editing tool.
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Affiliation(s)
- Krzysztof Chylinski
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, Umeå, Sweden
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Karvelis T, Gasiunas G, Miksys A, Barrangou R, Horvath P, Siksnys V. crRNA and tracrRNA guide Cas9-mediated DNA interference in Streptococcus thermophilus. RNA Biol 2013; 10:841-51. [PMID: 23535272 PMCID: PMC3737341 DOI: 10.4161/rna.24203] [Citation(s) in RCA: 167] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Cas9-crRNA complex of the Streptococcus thermophilus DGCC7710 CRISPR3-Cas system functions as an RNA-guided endonuclease with crRNA-directed target sequence recognition and protein-mediated DNA cleavage. We show here that an additional RNA molecule, tracrRNA (trans-activating CRISPR RNA), co-purifies with the Cas9 protein isolated from the heterologous E. coli strain carrying the S. thermophilus DGCC7710 CRISPR3-Cas system. We provide experimental evidence that tracrRNA is required for Cas9-mediated DNA interference both in vitro and in vivo. We show that Cas9 specifically promotes duplex formation between the precursor crRNA (pre-crRNA) transcript and tracrRNA, in vitro. Furthermore, the housekeeping RNase III contributes to primary pre-crRNA-tracrRNA duplex cleavage for mature crRNA biogenesis. RNase III, however, is not required in the processing of a short pre-crRNA transcribed from a minimal CRISPR array containing a single spacer. Finally, we show that an in vitro-assembled ternary Cas9-crRNA-tracrRNA complex cleaves DNA. This study further specifies the molecular basis for crRNA-based re-programming of Cas9 to specifically cleave any target DNA sequence for precise genome surgery. The processes for crRNA maturation and effector complex assembly established here will contribute to the further development of the Cas9 re-programmable system for genome editing applications.
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44
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Barrangou R. CRISPR-Cas systems and RNA-guided interference. WILEY INTERDISCIPLINARY REVIEWS-RNA 2013; 4:267-78. [DOI: 10.1002/wrna.1159] [Citation(s) in RCA: 137] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Bondy-Denomy J, Pawluk A, Maxwell KL, Davidson AR. Bacteriophage genes that inactivate the CRISPR/Cas bacterial immune system. Nature 2013; 493:429-32. [PMID: 23242138 PMCID: PMC4931913 DOI: 10.1038/nature11723] [Citation(s) in RCA: 562] [Impact Index Per Article: 51.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Accepted: 10/26/2012] [Indexed: 12/22/2022]
Abstract
A widespread system used by bacteria for protection against potentially dangerous foreign DNA molecules consists of the clustered regularly interspaced short palindromic repeats (CRISPR) coupled with cas (CRISPR-associated) genes. Similar to RNA interference in eukaryotes, these CRISPR/Cas systems use small RNAs for sequence-specific detection and neutralization of invading genomes. Here we describe the first examples of genes that mediate the inhibition of a CRISPR/Cas system. Five distinct 'anti-CRISPR' genes were found in the genomes of bacteriophages infecting Pseudomonas aeruginosa. Mutation of the anti-CRISPR gene of a phage rendered it unable to infect bacteria with a functional CRISPR/Cas system, and the addition of the same gene to the genome of a CRISPR/Cas-targeted phage allowed it to evade the CRISPR/Cas system. Phage-encoded anti-CRISPR genes may represent a widespread mechanism for phages to overcome the highly prevalent CRISPR/Cas systems. The existence of anti-CRISPR genes presents new avenues for the elucidation of CRISPR/Cas functional mechanisms and provides new insight into the co-evolution of phages and bacteria.
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Affiliation(s)
- Joe Bondy-Denomy
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - April Pawluk
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
| | - Karen L. Maxwell
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada M5S 3E1
| | - Alan R. Davidson
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada M5S 1A8
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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46
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Westra ER, Nilges B, van Erp PBG, van der Oost J, Dame RT, Brouns SJJ. Cascade-mediated binding and bending of negatively supercoiled DNA. RNA Biol 2012; 9:1134-8. [PMID: 22954644 DOI: 10.4161/rna.21410] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prokaryotes possess various defense mechanisms against invading DNA. Adaptive defense by CRISPR/Cas relies on incorporation of invader DNA sequences in the host genome. In Escherichia coli, processed transcripts of these incorporated sequences (crRNAs) guide Cascade-mediated invader DNA recognition. ( 1) (-) ( 4) Cascade is a multisubunit ribonucleoprotein complex, consisting of one crRNA and five proteins: Cse1, Cse2, Cas7, Cas5 and Cas6e. ( 1) (, ) ( 2) Cascade-mediated DNA recognition requires a conserved sequence adjacent to the target (protospacer adjacent motif, PAM) and a negatively supercoiled DNA topology. ( 3) (, ) ( 4) While Cse1 carries out PAM recognition, ( 5) the Cascade structure suggests that Cse2 may interact with target DNA in the PAM-distal end of the protospacer. ( 6) Using Electrophoretic Mobility Shift Assays, we here describe the function of the Cse1 and Cse2 subunits in the context of protospacer recognition on negatively supercoiled DNA. While Cse1 is required for nonspecific DNA binding, Cse2 appears to be important for specific binding, presumably by mediating stabilizing interactions with the displaced strand, the R-loop, or both. Furthermore, we performed Scanning Force Microscopy using linearized DNA molecules, which facilitates accurate and reliable measurements of Cascade-mediated bending. This analysis reveals that Cascade binding induces flexibility in the DNA target, most likely due to single stranded DNA regions flanking the R-loop.
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Affiliation(s)
- Edze R Westra
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, The Netherlands.
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47
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Swarts DC, Mosterd C, van Passel MWJ, Brouns SJJ. CRISPR interference directs strand specific spacer acquisition. PLoS One 2012; 7:e35888. [PMID: 22558257 PMCID: PMC3338789 DOI: 10.1371/journal.pone.0035888] [Citation(s) in RCA: 277] [Impact Index Per Article: 23.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Accepted: 03/28/2012] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND CRISPR/Cas is a widespread adaptive immune system in prokaryotes. This system integrates short stretches of DNA derived from invading nucleic acids into genomic CRISPR loci, which function as memory of previously encountered invaders. In Escherichia coli, transcripts of these loci are cleaved into small RNAs and utilized by the Cascade complex to bind invader DNA, which is then likely degraded by Cas3 during CRISPR interference. RESULTS We describe how a CRISPR-activated E. coli K12 is cured from a high copy number plasmid under non-selective conditions in a CRISPR-mediated way. Cured clones integrated at least one up to five anti-plasmid spacers in genomic CRISPR loci. New spacers are integrated directly downstream of the leader sequence. The spacers are non-randomly selected to target protospacers with an AAG protospacer adjacent motif, which is located directly upstream of the protospacer. A co-occurrence of PAM deviations and CRISPR repeat mutations was observed, indicating that one nucleotide from the PAM is incorporated as the last nucleotide of the repeat during integration of a new spacer. When multiple spacers were integrated in a single clone, all spacer targeted the same strand of the plasmid, implying that CRISPR interference caused by the first integrated spacer directs subsequent spacer acquisition events in a strand specific manner. CONCLUSIONS The E. coli Type I-E CRISPR/Cas system provides resistance against bacteriophage infection, but also enables removal of residing plasmids. We established that there is a positive feedback loop between active spacers in a cluster--in our case the first acquired spacer--and spacers acquired thereafter, possibly through the use of specific DNA degradation products of the CRISPR interference machinery by the CRISPR adaptation machinery. This loop enables a rapid expansion of the spacer repertoire against an actively present DNA element that is already targeted, amplifying the CRISPR interference effect.
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Affiliation(s)
- Daan C. Swarts
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Cas Mosterd
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Mark W. J. van Passel
- Systems and Synthetic Biology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
| | - Stan J. J. Brouns
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen, The Netherlands
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Sashital DG, Wiedenheft B, Doudna JA. Mechanism of foreign DNA selection in a bacterial adaptive immune system. Mol Cell 2012; 46:606-15. [PMID: 22521690 PMCID: PMC3397241 DOI: 10.1016/j.molcel.2012.03.020] [Citation(s) in RCA: 191] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 03/09/2012] [Accepted: 03/16/2012] [Indexed: 12/26/2022]
Abstract
In bacterial and archaeal CRISPR immune pathways, DNA sequences from invading bacteriophage or plasmids are integrated into CRISPR loci within the host genome, conferring immunity against subsequent infections. The ribonucleoprotein complex Cascade utilizes RNAs generated from these loci to target complementary "nonself" DNA sequences for destruction, while avoiding binding to "self" sequences within the CRISPR locus. Here we show that CasA, the largest protein subunit of Cascade, is required for nonself target recognition and binding. Combining a 2.3 Å crystal structure of CasA with cryo-EM structures of Cascade, we have identified a loop that is required for viral defense. This loop contacts a conserved three base pair motif that is required for nonself target selection. Our data suggest a model in which the CasA loop scans DNA for this short motif prior to target destabilization and binding, maximizing the efficiency of DNA surveillance by Cascade.
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Affiliation(s)
- Dipali G Sashital
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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49
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Juranek S, Eban T, Altuvia Y, Brown M, Morozov P, Tuschl T, Margalit H. A genome-wide view of the expression and processing patterns of Thermus thermophilus HB8 CRISPR RNAs. RNA (NEW YORK, N.Y.) 2012; 18:783-94. [PMID: 22355165 PMCID: PMC3312565 DOI: 10.1261/rna.031468.111] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2011] [Accepted: 01/01/2012] [Indexed: 05/31/2023]
Abstract
The CRISPR-Cas system represents an RNA-based adaptive immune response system in prokaryotes and archaea. CRISPRs (clustered regularly interspaced short palindromic repeats) consist of arrays of short repeat-sequences interspaced by nonrepetitive short spacers, some of which show sequence similarity to foreign phage genetic elements. Their cistronic transcripts are processed to produce the mature CRISPR RNAs (crRNAs), the elements that confer immunity by base-pairing with exogenous nucleic acids. We characterized the expression and processing patterns of Thermus thermophilus HB8 CRISPRs by using differential deep-sequencing, which differentiates between 5' monophosphate and 5' non-monophosphate-containing RNAs and/or between 3' hydroxyl and 3' non-hydroxyl-containing RNAs. The genome of T. thermophilus HB8 encodes 11 CRISPRs, classified into three distinct repeat-sequence types, all of which were constitutively expressed without deliberately infecting the bacteria with phage. Analysis of the differential deep sequencing data suggested that crRNAs are generated by endonucleolytic cleavage, leaving fragments with 5' hydroxyl and 3' phosphate or 2',3'-cyclic phosphate termini. The 5' ends of all crRNAs are generated by site-specific cleavage 8 nucleotides upstream of the spacer first position; however, the 3' ends are generated by two alternative, repeat-sequence-type-dependent mechanisms. These observations are consistent with the operation of multiple crRNA processing systems within a bacterial strain.
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Affiliation(s)
- Stefan Juranek
- Howard Hughes Medical Institute, Laboratory of RNA Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Tali Eban
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Canada-Israel, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Yael Altuvia
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Canada-Israel, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
| | - Miguel Brown
- Howard Hughes Medical Institute, Laboratory of RNA Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Pavel Morozov
- Howard Hughes Medical Institute, Laboratory of RNA Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Thomas Tuschl
- Howard Hughes Medical Institute, Laboratory of RNA Molecular Biology, The Rockefeller University, New York, New York 10065, USA
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Canada-Israel, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel
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50
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Characterization of the CRISPR/Cas subtype I-A system of the hyperthermophilic crenarchaeon Thermoproteus tenax. J Bacteriol 2012; 194:2491-500. [PMID: 22408157 DOI: 10.1128/jb.00206-12] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
CRISPR (clustered regularly interspaced short palindromic repeats) elements and cas (CRISPR-associated) genes are widespread in Bacteria and Archaea. The CRISPR/Cas system operates as a defense mechanism against mobile genetic elements (i.e., viruses or plasmids). Here, we investigate seven CRISPR loci in the genome of the crenarchaeon Thermoproteus tenax that include spacers with significant similarity not only to archaeal viruses but also to T. tenax genes. The analysis of CRISPR RNA (crRNA) transcription reveals transcripts of a length between 50 and 130 nucleotides, demonstrating the processing of larger crRNA precursors. The organization of identified cas genes resembles CRISPR/Cas subtype I-A, and the core cas genes are shown to be arranged on two polycistronic transcripts: cascis (cas4, cas1/2, and csa1) and cascade (csa5, cas7, cas5a, cas3, cas3', and cas8a2). Changes in the environmental parameters such as UV-light exposure or high ionic strength modulate cas gene transcription. Two reconstitution protocols were established for the production of two discrete multipartite Cas protein complexes that correspond to their operonic gene arrangement. These data provide insights into the specialized mechanisms of an archaeal CRISPR/Cas system and allow selective functional analyses of Cas protein complexes in the future.
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