1
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Zhang AN, Gaston JM, Cárdenas P, Zhao S, Gu X, Alm EJ. CRISPR-Cas spacer acquisition is a rare event in human gut microbiome. CELL GENOMICS 2025; 5:100725. [PMID: 39719706 PMCID: PMC11770219 DOI: 10.1016/j.xgen.2024.100725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2024] [Revised: 09/12/2024] [Accepted: 11/25/2024] [Indexed: 12/26/2024]
Abstract
Host-parasite relationships drive the evolution of both parties. In microbe-phage dynamics, CRISPR functions as an adaptive defense mechanism, updating immunity via spacer acquisition. Here, we investigated these interactions within the human gut microbiome, uncovering low frequencies of spacer acquisition at an average rate of one spacer every ∼2.9 point mutations using isolates' whole genomes and ∼2.7 years using metagenome time series. We identified a highly prevalent CRISPR array in Bifidobacterium longum spreading via horizontal gene transfer (HGT), with six spacers found in various genomic regions in 15 persons from the United States and Europe. These spacers, targeting two prominent Bifidobacterium phages, comprised 76% of spacer occurrence of all spacers targeting these phages in all B. longum populations. This result suggests that HGT of an entire CRISPR-Cas system introduced three times more spacers than local CRISPR-Cas acquisition in B. longum. Overall, our findings identified key ecological and evolutionary factors in prokaryote adaptive immunity.
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Affiliation(s)
- An-Ni Zhang
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
| | - Jeffry M Gaston
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore; Google, Cambridge, MA, USA
| | - Pablo Cárdenas
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Shijie Zhao
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Xiaoqiong Gu
- Singapore-MIT Alliance for Research and Technology, National University of Singapore, Singapore, Singapore
| | - Eric J Alm
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Center for Microbiome Informatics and Therapeutics, Massachusetts Institute of Technology, Cambridge, MA, USA.
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2
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Goldberg GW, Kogenaru M, Keegan S, Haase MAB, Kagermazova L, Arias MA, Onyebeke K, Adams S, Beyer DK, Fenyö D, Noyes MB, Boeke JD. Engineered transcription-associated Cas9 targeting in eukaryotic cells. Nat Commun 2024; 15:10287. [PMID: 39604381 PMCID: PMC11603292 DOI: 10.1038/s41467-024-54629-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2024] [Accepted: 11/18/2024] [Indexed: 11/29/2024] Open
Abstract
DNA targeting Class 2 CRISPR-Cas effector nucleases, including the well-studied Cas9 proteins, evolved protospacer-adjacent motif (PAM) and guide RNA interactions that sequentially license their binding and cleavage activities at protospacer target sites. Both interactions are nucleic acid sequence specific but function constitutively; thus, they provide intrinsic spatial control over DNA targeting activities but naturally lack temporal control. Here we show that engineered Cas9 fusion proteins which bind to nascent RNAs near a protospacer can facilitate spatiotemporal coupling between transcription and DNA targeting at that protospacer: Transcription-associated Cas9 Targeting (TraCT). Engineered TraCT is enabled in eukaryotic yeast or human cells when suboptimal PAM interactions limit basal activity and when one or more nascent RNA substrates are still tethered to the actively transcribed target DNA in cis. Using yeast, we further show that this phenomenon can be applied for selective editing at one of two identical targets in distinct gene loci, or, in diploid allelic loci that are differentially transcribed. Our work demonstrates that temporal control over Cas9's targeting activity at specific DNA sites may be engineered without modifying Cas9's core domains and guide RNA components or their expression levels. More broadly, it establishes co-transcriptional RNA binding as a cis-acting mechanism that can conditionally stimulate CRISPR-Cas DNA targeting in eukaryotic cells.
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Affiliation(s)
- Gregory W Goldberg
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA.
| | - Manjunatha Kogenaru
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Sarah Keegan
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Max A B Haase
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Larisa Kagermazova
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Mauricio A Arias
- Courant Institute of Mathematical Sciences, New York University, New York, NY, USA
| | - Kenenna Onyebeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Samantha Adams
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Daniel K Beyer
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - David Fenyö
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA
| | - Marcus B Noyes
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA.
| | - Jef D Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY, USA.
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn, NY, USA.
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3
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Goldberg GW, Kogenaru M, Keegan S, Haase MAB, Kagermazova L, Arias MA, Onyebeke K, Adams S, Beyer DK, Fenyö D, Noyes MB, Boeke JD. Engineered transcription-associated Cas9 targeting in eukaryotic cells. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.18.558319. [PMID: 37781609 PMCID: PMC10541143 DOI: 10.1101/2023.09.18.558319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
DNA targeting Class 2 CRISPR-Cas effector nucleases, including the well-studied Cas9 proteins, evolved protospacer-adjacent motif (PAM) and guide RNA interactions that sequentially license their binding and cleavage activities at protospacer target sites. Both interactions are nucleic acid sequence specific but function constitutively; thus, they provide intrinsic spatial control over DNA targeting activities but naturally lack temporal control. Here we show that engineered Cas9 fusion proteins which bind to nascent RNAs near a protospacer can facilitate spatiotemporal coupling between transcription and DNA targeting at that protospacer: Transcription-associated Cas9 Targeting (TraCT). Engineered TraCT is enabled in eukaryotic yeast or human cells when suboptimal PAM interactions limit basal activity and when one or more nascent RNA substrates are still tethered to the actively transcribed target DNA in cis. Using yeast, we further show that this phenomenon can be applied for selective editing at one of two identical targets in distinct gene loci, or, in diploid allelic loci that are differentially transcribed. Our work demonstrates that temporal control over Cas9's targeting activity at specific DNA sites may be engineered without modifying Cas9's core domains and guide RNA components or their expression levels. More broadly, it establishes co-transcriptional RNA binding as a cis-acting mechanism that can conditionally stimulate CRISPR-Cas DNA targeting in eukaryotic cells.
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Affiliation(s)
- Gregory W. Goldberg
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Manjunatha Kogenaru
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Sarah Keegan
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Max A. B. Haase
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Larisa Kagermazova
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Mauricio A. Arias
- Courant Institute of Mathematical Sciences, New York University, New York, NY 10012, USA
| | - Kenenna Onyebeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Samantha Adams
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Daniel K. Beyer
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - David Fenyö
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Marcus B. Noyes
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
| | - Jef D. Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular Pharmacology, NYU Langone Health, New York, NY 10016, USA
- Department of Biomedical Engineering, NYU Tandon School of Engineering, Brooklyn NY 11201
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4
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Ganguly C, Rostami S, Long K, Aribam SD, Rajan R. Unity among the diverse RNA-guided CRISPR-Cas interference mechanisms. J Biol Chem 2024; 300:107295. [PMID: 38641067 PMCID: PMC11127173 DOI: 10.1016/j.jbc.2024.107295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 04/08/2024] [Accepted: 04/10/2024] [Indexed: 04/21/2024] Open
Abstract
CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) systems are adaptive immune systems that protect bacteria and archaea from invading mobile genetic elements (MGEs). The Cas protein-CRISPR RNA (crRNA) complex uses complementarity of the crRNA "guide" region to specifically recognize the invader genome. CRISPR effectors that perform targeted destruction of the foreign genome have emerged independently as multi-subunit protein complexes (Class 1 systems) and as single multi-domain proteins (Class 2). These different CRISPR-Cas systems can cleave RNA, DNA, and protein in an RNA-guided manner to eliminate the invader, and in some cases, they initiate programmed cell death/dormancy. The versatile mechanisms of the different CRISPR-Cas systems to target and destroy nucleic acids have been adapted to develop various programmable-RNA-guided tools and have revolutionized the development of fast, accurate, and accessible genomic applications. In this review, we present the structure and interference mechanisms of different CRISPR-Cas systems and an analysis of their unified features. The three types of Class 1 systems (I, III, and IV) have a conserved right-handed helical filamentous structure that provides a backbone for sequence-specific targeting while using unique proteins with distinct mechanisms to destroy the invader. Similarly, all three Class 2 types (II, V, and VI) have a bilobed architecture that binds the RNA-DNA/RNA hybrid and uses different nuclease domains to cleave invading MGEs. Additionally, we highlight the mechanistic similarities of CRISPR-Cas enzymes with other RNA-cleaving enzymes and briefly present the evolutionary routes of the different CRISPR-Cas systems.
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Affiliation(s)
- Chhandosee Ganguly
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Saadi Rostami
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Kole Long
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Swarmistha Devi Aribam
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA
| | - Rakhi Rajan
- Department of Chemistry and Biochemistry, Price Family Foundation Institute of Structural Biology, Stephenson Life Sciences Research Center, University of Oklahoma, Norman, Oklahoma, USA.
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5
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Nweze JE, Schweichhart JS, Angel R. Viral communities in millipede guts: Insights into the diversity and potential role in modulating the microbiome. Environ Microbiol 2024; 26:e16586. [PMID: 38356108 DOI: 10.1111/1462-2920.16586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/22/2024] [Indexed: 02/16/2024]
Abstract
Millipedes are important detritivores harbouring a diverse microbiome. Previous research focused on bacterial and archaeal diversity, while the virome remained neglected. We elucidated the DNA and RNA viral diversity in the hindguts of two model millipede species with distinct microbiomes: the tropical Epibolus pulchripes (methanogenic, dominated by Bacillota) and the temperate Glomeris connexa (non-methanogenic, dominated by Pseudomonadota). Based on metagenomic and metatranscriptomic assembled viral genomes, the viral communities differed markedly and preferentially infected the most abundant prokaryotic taxa. The majority of DNA viruses were Caudoviricetes (dsDNA), Cirlivirales (ssDNA) and Microviridae (ssDNA), while RNA viruses consisted of Leviviricetes (ssRNA), Potyviridae (ssRNA) and Eukaryotic viruses. A high abundance of subtypes I-C, I-B and II-C CRISPR-Cas systems was found, primarily from Pseudomonadota, Bacteroidota and Bacillota. In addition, auxiliary metabolic genes that modulate chitin degradation, vitamins and amino acid biosynthesis and sulphur metabolism were also detected. Lastly, we found low virus-to-microbe-ratios and a prevalence of lysogenic viruses, supporting a Piggyback-the-Winner dynamic in both hosts.
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Affiliation(s)
- Julius Eyiuche Nweze
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czechia
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia
| | - Johannes Sergej Schweichhart
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czechia
- Department of Ecosystem Biology, Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czechia
| | - Roey Angel
- Institute of Soil Biology and Biogeochemistry, Biology Centre CAS, České Budějovice, Czechia
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6
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Lucas-Elío P, ElAlami T, Martínez A, Sanchez-Amat A. Marinomonas mediterranea synthesizes an R-type bacteriocin. Appl Environ Microbiol 2024; 90:e0127323. [PMID: 38169292 PMCID: PMC10870725 DOI: 10.1128/aem.01273-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/17/2023] [Indexed: 01/05/2024] Open
Abstract
Prophages integrated into bacterial genomes can become cryptic or defective prophages, which may evolve to provide various traits to bacterial cells. Previous research on Marinomonas mediterranea MMB-1 demonstrated the production of defective particles. In this study, an analysis of the genomes of three different strains (MMB-1, MMB-2, and MMB-3) revealed the presence of a region named MEDPRO1, spanning approximately 52 kb, coding for a defective prophage in strains MMB-1 and MMB-2. This prophage seems to have been lost in strain MMB-3, possibly due to the presence of spacers recognizing this region in an I-F CRISPR array in this strain. However, all three strains produce remarkably similar defective particles. Using strain MMB-1 as a model, mass spectrometry analyses indicated that the structural proteins of the defective particles are encoded by a second defective prophage situated within the MEDPRO2 region, spanning approximately 13 kb. This finding was further validated through the deletion of this second defective prophage. Genomic region analyses and the detection of antimicrobial activity of the defective prophage against other Marinomonas species suggest that it is an R-type bacteriocin. Marinomonas mediterranea synthesizes antimicrobial proteins with lysine oxidase activity, and the synthesis of an R-type bacteriocin constitutes an additional mechanism in microbial competition for the colonization of habitats such as the surface of marine plants.IMPORTANCEThe interactions between bacterial strains inhabiting the same environment determine the final composition of the microbiome. In this study, it is shown that some extracellular defective phage particles previously observed in Marinomonas mediterranea are in fact R-type bacteriocins showing antimicrobial activity against other Marinomonas strains. The operon coding for the R-type bacteriocin has been identified.
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Affiliation(s)
- Patricia Lucas-Elío
- Department of Genetics and Microbiology, University of Murcia, Murcia, Spain
| | - Tarik ElAlami
- Department of Genetics and Microbiology, University of Murcia, Murcia, Spain
| | - Alicia Martínez
- Department of Genetics and Microbiology, University of Murcia, Murcia, Spain
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7
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Lee IPA, Eldakar OT, Gogarten JP, Andam CP. Recombination as an enforcement mechanism of prosocial behavior in cooperating bacteria. iScience 2023; 26:107344. [PMID: 37554437 PMCID: PMC10405257 DOI: 10.1016/j.isci.2023.107344] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/11/2023] [Accepted: 07/06/2023] [Indexed: 08/10/2023] Open
Abstract
Prosocial behavior is ubiquitous in nature despite the relative fitness costs carried by cooperative individuals. However, the stability of cooperation in populations is fragile and often maintained through enforcement. We propose that homologous recombination provides such a mechanism in bacteria. Using an agent-based model of recombination in bacteria playing a public goods game, we demonstrate how changes in recombination rates affect the proportion of cooperating cells. In our model, recombination converts cells to a different strategy, either freeloading (cheaters) or cooperation, based on the strategies of neighboring cells and recombination rate. Increasing the recombination rate expands the parameter space in which cooperators outcompete freeloaders. However, increasing the recombination rate alone is neither sufficient nor necessary. Intermediate benefits of cooperation, lower population viscosity, and greater population size can promote the evolution of cooperation from within populations of cheaters. Our findings demonstrate how recombination influences the persistence of cooperative behavior in bacteria.
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Affiliation(s)
- Isaiah Paolo A. Lee
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
- National Institute of Molecular Biology and Biotechnology, University of the Philippines–Diliman, Quezon City 1101, Philippines
| | - Omar Tonsi Eldakar
- Department of Biological Sciences, Nova Southeastern University, Fort Lauderdale, FL 33328, USA
| | - J. Peter Gogarten
- Department of Molecular and Cell Biology, University of Connecticut, Storrs, CT 06269, USA
| | - Cheryl P. Andam
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
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8
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Abstract
CRISPR-Cas is a widespread adaptive immune system in bacteria and archaea that protects against viral infection by targeting specific invading nucleic acid sequences. Whereas some CRISPR-Cas systems sense and cleave viral DNA, type III and type VI CRISPR-Cas systems sense RNA that results from viral transcription and perhaps invasion by RNA viruses. The sequence-specific detection of viral RNA evokes a cell-wide response that typically involves global damage to halt the infection. How can one make sense of an immune strategy that encompasses broad, collateral effects rather than specific, targeted destruction? In this Review, we summarize the current understanding of RNA-targeting CRISPR-Cas systems. We detail the composition and properties of type III and type VI systems, outline the cellular defence processes that are instigated upon viral RNA sensing and describe the biological rationale behind the broad RNA-activated immune responses as an effective strategy to combat viral infection.
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9
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Song S, Semenova E, Severinov K, Fernández-García L, Benedik MJ, Maeda T, Wood TK. CRISPR-Cas Controls Cryptic Prophages. Int J Mol Sci 2022; 23:16195. [PMID: 36555835 PMCID: PMC9782134 DOI: 10.3390/ijms232416195] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022] Open
Abstract
The bacterial archetypal adaptive immune system, CRISPR-Cas, is thought to be repressed in the best-studied bacterium, Escherichia coli K-12. We show here that the E. coli CRISPR-Cas system is active and serves to inhibit its nine defective (i.e., cryptic) prophages. Specifically, compared to the wild-type strain, reducing the amounts of specific interfering RNAs (crRNA) decreases growth by 40%, increases cell death by 700%, and prevents persister cell resuscitation. Similar results were obtained by inactivating CRISPR-Cas by deleting the entire 13 spacer region (CRISPR array); hence, CRISPR-Cas serves to inhibit the remaining deleterious effects of these cryptic prophages, most likely through CRISPR array-derived crRNA binding to cryptic prophage mRNA rather than through cleavage of cryptic prophage DNA, i.e., self-targeting. Consistently, four of the 13 E. coli spacers contain complementary regions to the mRNA sequences of seven cryptic prophages, and inactivation of CRISPR-Cas increases the level of mRNA for lysis protein YdfD of cryptic prophage Qin and lysis protein RzoD of cryptic prophage DLP-12. In addition, lysis is clearly seen via transmission electron microscopy when the whole CRISPR-Cas array is deleted, and eliminating spacer #12, which encodes crRNA with complementary regions for DLP-12 (including rzoD), Rac, Qin (including ydfD), and CP4-57 cryptic prophages, also results in growth inhibition and cell lysis. Therefore, we report the novel results that (i) CRISPR-Cas is active in E. coli and (ii) CRISPR-Cas is used to tame cryptic prophages, likely through RNAi, i.e., unlike with active lysogens, active CRISPR-Cas and cryptic prophages may stably co-exist.
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Affiliation(s)
- Sooyeon Song
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802, USA
- Department of Animal Science, Jeonbuk National University, Jeonju-Si 54896, Republic of Korea
- Agricultural Convergence Technology, Jeonbuk National University, Jeonju-Si 54896, Republic of Korea
| | - Ekaterina Semenova
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Konstantin Severinov
- Waksman Institute of Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
| | - Laura Fernández-García
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802, USA
| | - Michael J. Benedik
- Office of the Provost, Hamad bin Khalifa University, Education City, Doha P.O. Box 34110, Qatar
| | - Toshinari Maeda
- Department of Biological Functions Engineering, Kyushu Institute of Technology, Kitakyushu 808-0196, Japan
| | - Thomas K. Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802, USA
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10
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Chen H, Mayer A, Balasubramanian V. A scaling law in CRISPR repertoire sizes arises from the avoidance of autoimmunity. Curr Biol 2022; 32:2897-2907.e5. [PMID: 35659862 DOI: 10.1016/j.cub.2022.05.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/13/2022] [Accepted: 05/09/2022] [Indexed: 12/28/2022]
Abstract
Some prokaryotes possess CRISPR-Cas systems that use DNA segments called spacers, which are acquired from invading phages, to guide immune defense. Here, we propose that cross-reactive CRISPR targeting can, however, lead to "heterologous autoimmunity," whereby foreign spacers guide self-targeting in a spacer-length-dependent fashion. Balancing antiviral defense against autoimmunity predicts a scaling relation between spacer length and CRISPR repertoire size. We find evidence for this scaling through a comparative analysis of sequenced prokaryotic genomes and show that this association also holds at the level of CRISPR types. By contrast, the scaling is absent in strains with nonfunctional CRISPR loci. Finally, we demonstrate that stochastic spacer loss can explain variations around the scaling relation, even between strains of the same species. Our results suggest that heterologous autoimmunity is a selective factor shaping the evolution of CRISPR-Cas systems, analogous to the trade-offs between immune specificity, breadth, and autoimmunity that constrain the diversity of adaptive immune systems in vertebrates.
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Affiliation(s)
- Hanrong Chen
- David Rittenhouse Laboratory, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA; Laboratory of Metagenomic Technologies and Microbial Systems, Genome Institute of Singapore, Singapore 138672, Singapore.
| | - Andreas Mayer
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
| | - Vijay Balasubramanian
- David Rittenhouse Laboratory, Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104, USA; Theoretische Natuurkunde, Vrije Universiteit Brussel, 1050 Brussels, Belgium
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11
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Grüschow S, Adamson CS, White MF. Specificity and sensitivity of an RNA targeting type III CRISPR complex coupled with a NucC endonuclease effector. Nucleic Acids Res 2021; 49:13122-13134. [PMID: 34871408 PMCID: PMC8682760 DOI: 10.1093/nar/gkab1190] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/12/2021] [Accepted: 11/17/2021] [Indexed: 12/26/2022] Open
Abstract
Type III CRISPR systems detect invading RNA, resulting in the activation of the enzymatic Cas10 subunit. The Cas10 cyclase domain generates cyclic oligoadenylate (cOA) second messenger molecules, activating a variety of effector nucleases that degrade nucleic acids to provide immunity. The prophage-encoded Vibrio metoecus type III-B (VmeCmr) locus is uncharacterised, lacks the HD nuclease domain in Cas10 and encodes a NucC DNA nuclease effector that is also found associated with Cyclic-oligonucleotide-based anti-phage signalling systems (CBASS). Here we demonstrate that VmeCmr is activated by target RNA binding, generating cyclic-triadenylate (cA3) to stimulate a robust NucC-mediated DNase activity. The specificity of VmeCmr is probed, revealing the importance of specific nucleotide positions in segment 1 of the RNA duplex and the protospacer flanking sequence (PFS). We harness this programmable system to demonstrate the potential for a highly specific and sensitive assay for detection of the SARS-CoV-2 virus RNA with a limit of detection (LoD) of 2 fM using a commercial plate reader without any extrinsic amplification step. The sensitivity is highly dependent on the guide RNA used, suggesting that target RNA secondary structure plays an important role that may also be relevant in vivo.
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Affiliation(s)
- Sabine Grüschow
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Catherine S Adamson
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, KY16 9ST, UK
| | - Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, KY16 9ST, UK
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12
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Devi V, Harjai K, Chhibber S. Self-targeting spacers in CRISPR-array: Accidental occurrence or evolutionarily conserved phenomenon. J Basic Microbiol 2021; 62:4-12. [PMID: 34904260 DOI: 10.1002/jobm.202100514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/18/2021] [Accepted: 11/27/2021] [Indexed: 11/12/2022]
Abstract
In recent years, a tremendous amount of inquisitiveness among scientists in the clustered regularly interspaced short palindrome repeats (CRISPR)-CRISPR-associated proteins (Cas) has led to many studies to delineate their exact role in prokaryotes. CRISPR-Cas is an adaptive immune system that protects prokaryotes from phages and mobile genetic elements. It incorporates small DNA fragment of the invader in the CRISPR-array and protects the host from future invasion by them. In a few instances, the CRISPR-array also incorporates self-targeting spacers, most likely by accident or leaky incorporation. A significant number of spacers are found to match with the host genes across the species; however, self-targeting spacers have not been investigated in detail in most of the organisms. The presence of self-targeting spacers in the CRISPR-array led to speculation that the CRISPR-Cas system has a lot more to offer than just being the conventional adaptive immune system. It has been implicated in gene regulation and autoimmunity more or less equally. In this review, an attempt has been made to understand self-targeting spacers in the context of gene regulation, autoimmunity, and its avoidance strategies.
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Affiliation(s)
- Veena Devi
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Kusum Harjai
- Department of Microbiology, Panjab University, Chandigarh, India
| | - Sanjay Chhibber
- Department of Microbiology, Panjab University, Chandigarh, India
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13
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Steens JA, Zhu Y, Taylor DW, Bravo JPK, Prinsen SHP, Schoen CD, Keijser BJF, Ossendrijver M, Hofstra LM, Brouns SJJ, Shinkai A, van der Oost J, Staals RHJ. SCOPE enables type III CRISPR-Cas diagnostics using flexible targeting and stringent CARF ribonuclease activation. Nat Commun 2021; 12:5033. [PMID: 34413302 PMCID: PMC8376896 DOI: 10.1038/s41467-021-25337-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 07/30/2021] [Indexed: 02/07/2023] Open
Abstract
Characteristic properties of type III CRISPR-Cas systems include recognition of target RNA and the subsequent induction of a multifaceted immune response. This involves sequence-specific cleavage of the target RNA and production of cyclic oligoadenylate (cOA) molecules. Here we report that an exposed seed region at the 3' end of the crRNA is essential for target RNA binding and cleavage, whereas cOA production requires base pairing at the 5' end of the crRNA. Moreover, we uncover that the variation in the size and composition of type III complexes within a single host results in variable seed regions. This may prevent escape by invading genetic elements, while controlling cOA production tightly to prevent unnecessary damage to the host. Lastly, we use these findings to develop a new diagnostic tool, SCOPE, for the specific detection of SARS-CoV-2 from human nasal swab samples, revealing sensitivities in the atto-molar range.
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Affiliation(s)
- Jurre A Steens
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
- Scope Biosciences, Wageningen, The Netherlands
| | - Yifan Zhu
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands.
| | - David W Taylor
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX, USA
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA
- LIVESTRONG Cancer Institutes, Dell Medical School, Austin, TX, USA
| | - Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | | | - Cor D Schoen
- BioInteractions and Plant Health, Wageningen Plant Research, Wageningen, The Netherlands
| | | | | | - L Marije Hofstra
- Virology, Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, The Netherlands
| | - Akeo Shinkai
- RIKEN SPring-8 Center, Sayo, Hyogo, Japan
- RIKEN Cluster for Pioneering Research, Wako, Saitama, Japan
| | - John van der Oost
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Raymond H J Staals
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands.
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14
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Dimitriu T, Szczelkun MD, Westra ER. Evolutionary Ecology and Interplay of Prokaryotic Innate and Adaptive Immune Systems. Curr Biol 2021; 30:R1189-R1202. [PMID: 33022264 DOI: 10.1016/j.cub.2020.08.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Like many organisms, bacteria and archaea have both innate and adaptive immune systems to defend against infection by viruses and other parasites. Innate immunity most commonly relies on the endonuclease-mediated cleavage of any incoming DNA that lacks a specific epigenetic modification, through a system known as restriction-modification. CRISPR-Cas-mediated adaptive immunity relies on the insertion of short DNA sequences from parasite genomes into CRISPR arrays on the host genome to provide sequence-specific protection. The discovery of each of these systems has revolutionised our ability to carry out genetic manipulations, and, as a consequence, the enzymes involved have been characterised in exquisite detail. In comparison, much less is known about the importance of these two arms of the defence for the ecology and evolution of prokaryotes and their parasites. Here, we review our current ecological and evolutionary understanding of these systems in isolation, and discuss the need to study how innate and adaptive immune responses are integrated when they coexist in the same cell.
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Affiliation(s)
- Tatiana Dimitriu
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK.
| | - Mark D Szczelkun
- DNA-Protein Interactions Unit, School of Biochemistry, University of Bristol, Bristol BS8 1TD, UK.
| | - Edze R Westra
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn TR10 9FE, UK.
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15
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Abstract
CRISPR-Cas systems provide bacteria and archaea with adaptive, heritable immunity against their viruses (bacteriophages and phages) and other parasitic genetic elements. CRISPR-Cas systems are highly diverse, and we are only beginning to understand their relative importance in phage defense. In this review, we will discuss when and why CRISPR-Cas immunity against phages evolves, and how this, in turn, selects for the evolution of immune evasion by phages. Finally, we will discuss our current understanding of if, and when, we observe coevolution between CRISPR-Cas systems and phages, and how this may be influenced by the mechanism of CRISPR-Cas immunity.
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16
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Orellana R, Arancibia A, Badilla L, Acosta J, Arancibia G, Escar R, Ferrada G, Seeger M. Ecophysiological Features Shape the Distribution of Prophages and CRISPR in Sulfate Reducing Prokaryotes. Microorganisms 2021; 9:microorganisms9050931. [PMID: 33925267 PMCID: PMC8146710 DOI: 10.3390/microorganisms9050931] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/18/2021] [Accepted: 04/23/2021] [Indexed: 12/28/2022] Open
Abstract
Sulfate reducing prokaryotes (SRP) are a phylogenetically and physiologically diverse group of microorganisms that use sulfate as an electron acceptor. SRP have long been recognized as key players of the carbon and sulfur cycles, and more recently, they have been identified to play a relevant role as part of syntrophic and symbiotic relations and the human microbiome. Despite their environmental relevance, there is a poor understanding about the prevalence of prophages and CRISPR arrays and how their distribution and dynamic affect the ecological role of SRP. We addressed this question by analyzing the results of a comprehensive survey of prophages and CRISPR in a total of 91 genomes of SRP with several genotypic, phenotypic, and physiological traits, including genome size, cell volume, minimum doubling time, cell wall, and habitat, among others. Our analysis discovered 81 prophages in 51 strains, representing the 56% of the total evaluated strains. Prophages are non-uniformly distributed across the SRP phylogeny, where prophage-rich lineages belonged to Desulfovibrionaceae and Peptococcaceae. Furthermore, our study found 160 CRISPR arrays in 71 SRP, which is more abundant and widely spread than previously expected. Although there is no correlation between presence and abundance of prophages and CRISPR arrays at the strain level, our analysis showed that there is a directly proportional relation between cellular volumes and number of prophages per cell. This result suggests that there is an additional selective pressure for strains with smaller cells to get rid of foreign DNA, such as prophages, but not CRISPR, due to less availability of cellular resources. Analysis of the prophage genes encoding viral structural proteins reported that 44% of SRP prophages are classified as Myoviridae, and comparative analysis showed high level of homology, but not synteny, among prophages belonging to the Family Desulfovibrionaceae. We further recovered viral-like particles and structures that resemble outer membrane vesicles from D. vulgaris str. Hildenborough. The results of this study improved the current understanding of dynamic interactions between prophages and CRISPR with their hosts in both cultured and hitherto-uncultured SRP strains, and how their distribution affects the microbial community dynamics in several sulfidogenic natural and engineered environments.
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Affiliation(s)
- Roberto Orellana
- Laboratorio de Biología Celular y Ecofisiología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Leopoldo Carvallo 270, Valparaíso 2360001, Chile; (A.A.); (L.B.)
- Correspondence:
| | - Alejandra Arancibia
- Laboratorio de Biología Celular y Ecofisiología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Leopoldo Carvallo 270, Valparaíso 2360001, Chile; (A.A.); (L.B.)
| | - Leonardo Badilla
- Laboratorio de Biología Celular y Ecofisiología Microbiana, Facultad de Ciencias Naturales y Exactas, Universidad de Playa Ancha, Leopoldo Carvallo 270, Valparaíso 2360001, Chile; (A.A.); (L.B.)
| | - Jonathan Acosta
- Departamento de Estadística, Pontificia Universidad Católica de Chile, Avda. Vicuña Mackenna 4860, Santiago 7820436, Chile;
| | - Gabriela Arancibia
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| | - Rodrigo Escar
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| | - Gustavo Ferrada
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
| | - Michael Seeger
- Laboratorio de Microbiología Molecular y Biotecnología Ambiental, Departamento de Química & Centro de Biotecnología Daniel Alkalay-Lowitt, Universidad Técnica Federico Santa María, Avenida España 1680, Valparaíso 2390123, Chile; (G.A.); (R.E.); (G.F.); (M.S.)
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17
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Huang F, Zhu B. The Cyclic Oligoadenylate Signaling Pathway of Type III CRISPR-Cas Systems. Front Microbiol 2021; 11:602789. [PMID: 33552016 PMCID: PMC7854544 DOI: 10.3389/fmicb.2020.602789] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 11/11/2020] [Indexed: 12/24/2022] Open
Abstract
Type III CRISPR-Cas systems, which are widespread in both bacteria and archaea, provide immunity against DNA viruses and plasmids in a transcription-dependent manner. Since an unprecedented cyclic oligoadenylate (cOA) signaling pathway was discovered in type III systems in 2017, the cOA signaling has been extensively studied in recent 3 years, which has expanded our understanding of type III systems immune defense and also its counteraction by viruses. In this review, we summarized recent advances in cOA synthesis, cOA-activated effector protein, cOA signaling-mediated immunoprotection, and cOA signaling inhibition, and highlighted the crosstalk between cOA signaling and other cyclic oligonucleotide-mediated immunity discovered very recently.
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Affiliation(s)
- Fengtao Huang
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, China
| | - Bin Zhu
- Key Laboratory of Molecular Biophysics, the Ministry of Education, College of Life Science and Technology and Shenzhen College, Huazhong University of Science and Technology, Wuhan, China
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18
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Abstract
Bacteriophages encode diverse anti-CRISPR (Acr) proteins that inhibit CRISPR-Cas immunity during infection of their bacterial hosts. Although detailed mechanisms have been characterized for multiple Acr proteins, an understanding of their role in phage infection biology is just emerging. Here, we review recent work in this area and propose a framework of "phage autonomy" to evaluate CRISPR-immune evasion strategies. During phage infection, Acr proteins are deployed by a tightly regulated "fast on-fast off" transcriptional burst, which is necessary, but insufficient, for CRISPR-Cas inactivation. Instead of a single phage shutting down CRISPR-Cas immunity, a community of acr-carrying phages cooperate to suppress bacterial immunity, displaying low phage autonomy. Enzymatic Acr proteins with novel mechanisms have been recently revealed and are predicted to enhance phage autonomy, while phage DNA protective measures offer the highest phage autonomy observed. These varied Acr mechanisms and strengths also have unexpected impacts on the bacterial populations and competing phages.
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Affiliation(s)
- Yuping Li
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94403, USA
| | - Joseph Bondy-Denomy
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94403, USA; Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94403, USA; Innovative Genomics Institute, Berkeley, CA, USA.
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19
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Nobrega FL, Walinga H, Dutilh BE, Brouns SJJ. Prophages are associated with extensive CRISPR-Cas auto-immunity. Nucleic Acids Res 2020; 48:12074-12084. [PMID: 33219687 PMCID: PMC7708048 DOI: 10.1093/nar/gkaa1071] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 10/19/2020] [Accepted: 10/22/2020] [Indexed: 12/26/2022] Open
Abstract
CRISPR-Cas systems require discriminating self from non-self DNA during adaptation and interference. Yet, multiple cases have been reported of bacteria containing self-targeting spacers (STS), i.e. CRISPR spacers targeting protospacers on the same genome. STS has been suggested to reflect potential auto-immunity as an unwanted side effect of CRISPR-Cas defense, or a regulatory mechanism for gene expression. Here we investigated the incidence, distribution, and evasion of STS in over 100 000 bacterial genomes. We found STS in all CRISPR-Cas types and in one fifth of all CRISPR-carrying bacteria. Notably, up to 40% of I-B and I-F CRISPR-Cas systems contained STS. We observed that STS-containing genomes almost always carry a prophage and that STS map to prophage regions in more than half of the cases. Despite carrying STS, genetic deterioration of CRISPR-Cas systems appears to be rare, suggesting a level of escape from the potentially deleterious effects of STS by other mechanisms such as anti-CRISPR proteins and CRISPR target mutations. We propose a scenario where it is common to acquire an STS against a prophage, and this may trigger more extensive STS buildup by primed spacer acquisition in type I systems, without detrimental autoimmunity effects as mechanisms of auto-immunity evasion create tolerance to STS-targeted prophages.
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Affiliation(s)
- Franklin L Nobrega
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands.,Kavli Institute of Nanoscience, Delft, Netherlands
| | - Hielke Walinga
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands.,Kavli Institute of Nanoscience, Delft, Netherlands
| | - Bas E Dutilh
- Theoretical Biology and Bioinformatics, Science4Life, Utrecht University, Utrecht, Netherlands
| | - Stan J J Brouns
- Department of Bionanoscience, Delft University of Technology, Delft, Netherlands.,Kavli Institute of Nanoscience, Delft, Netherlands
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20
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Benler S, Koonin EV. Phage lysis‐lysogeny switches and programmed cell death: Danse macabre. Bioessays 2020; 42:e2000114. [DOI: 10.1002/bies.202000114] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/25/2020] [Indexed: 01/04/2023]
Affiliation(s)
- Sean Benler
- National Center for Biotechnology Information National Library of Medicine National Institutes of Health Bethesda Maryland USA
| | - Eugene V. Koonin
- National Center for Biotechnology Information National Library of Medicine National Institutes of Health Bethesda Maryland USA
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21
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Westra ER, Levin BR. It is unclear how important CRISPR-Cas systems are for protecting natural populations of bacteria against infections by mobile genetic elements. Proc Natl Acad Sci U S A 2020; 117:27777-27785. [PMID: 33122438 PMCID: PMC7668106 DOI: 10.1073/pnas.1915966117] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Articles on CRISPR commonly open with some variant of the phrase "these short palindromic repeats and their associated endonucleases (Cas) are an adaptive immune system that exists to protect bacteria and archaea from viruses and infections with other mobile genetic elements." There is an abundance of genomic data consistent with the hypothesis that CRISPR plays this role in natural populations of bacteria and archaea, and experimental demonstrations with a few species of bacteria and their phage and plasmids show that CRISPR-Cas systems can play this role in vitro. Not at all clear are the ubiquity, magnitude, and nature of the contribution of CRISPR-Cas systems to the ecology and evolution of natural populations of microbes and the strength of selection mediated by different types of phage and plasmids to the evolution and maintenance of CRISPR-Cas systems. In this perspective, with the aid of heuristic mathematical-computer simulation models, we explore the a priori conditions under which exposure to lytic and temperate phage and conjugative plasmids will select for and maintain CRISPR-Cas systems in populations of bacteria and archaea. We review the existing literature addressing these ecological and evolutionary questions and highlight the experimental and other evidence needed to fully understand the conditions responsible for the evolution and maintenance of CRISPR-Cas systems and the contribution of these systems to the ecology and evolution of bacteria, archaea, and the mobile genetic elements that infect them.
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Affiliation(s)
- Edze R Westra
- Environment and Sustainability Institute, Biosciences, University of Exeter, Penryn, TR10 9FE Cornwall, United Kingdom;
| | - Bruce R Levin
- Department of Biology, Emory University, Atlanta, GA 30307
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22
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Pei Z, Sadiq FA, Han X, Zhao J, Zhang H, Ross RP, Lu W, Chen W. Identification, characterization, and phylogenetic analysis of eight new inducible prophages in Lactobacillus. Virus Res 2020; 286:198003. [PMID: 32450182 DOI: 10.1016/j.virusres.2020.198003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 04/26/2020] [Accepted: 04/29/2020] [Indexed: 10/24/2022]
Abstract
Lysogenic bacterial strains abound in the Lactobacillus genus and contain dormant prophages inserted within their genomes. To evaluate the prophage-induction potential of the Lactobacillus strains of six species, 142 randomly selected strains from these species were induced with Mitomycin C. Eight newly-induced phages were identified and found to be diverse in morphology. Among the six species assessed, Lactobacillus plantarum and Lactobacillus rhamnosus strains were generally insensitive to induction. The genomic characterizations of eight phages were performed via whole genome sequencing and protein prediction. Meanwhile, genome comparison of the induced phages and predicted prophages demonstrated that the prediction software PHASTER can accurately locate major prophage regions in Lactobacillus. A phylogenetic tree of the Lactobacillus phage population was constructed to obtain further insights into the clustering of individuals, two major groups were found, one of which consisted mostly of L. plantarum virulent phages, the other was represented by Lactobacillus casei/paracasei temperate phages. Finally, it was confirmed via genomic collinear analysis, which seven of the eight Lactobacillus temperate phages were newly discovered, and two Lactobacillus brevis temperate phages belonged to a novel lineage.
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Affiliation(s)
- Zhangming Pei
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Faizan Ahmed Sadiq
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Xiao Han
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
| | - Jianxin Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; International Joint Research Center for Probiotics & Gut Health, Jiangnan University, Wuxi, Jiangsu, China
| | - Hao Zhang
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; International Joint Research Center for Probiotics & Gut Health, Jiangnan University, Wuxi, Jiangsu, China
| | - R Paul Ross
- International Joint Research Center for Probiotics & Gut Health, Jiangnan University, Wuxi, Jiangsu, China; APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Wenwei Lu
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China
| | - Wei Chen
- State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; National Engineering Research Center for Functional Food, Jiangnan University, Wuxi 214122, China; International Joint Research Center for Probiotics & Gut Health, Jiangnan University, Wuxi, Jiangsu, China; Beijing Innovation Centre of Food Nutrition and Human Health, Beijing Technology and Business University (BTBU), Beijing 100048, China.
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23
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Burmistrz M, Krakowski K, Krawczyk-Balska A. RNA-Targeting CRISPR-Cas Systems and Their Applications. Int J Mol Sci 2020; 21:ijms21031122. [PMID: 32046217 PMCID: PMC7036953 DOI: 10.3390/ijms21031122] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 01/29/2020] [Accepted: 02/04/2020] [Indexed: 12/16/2022] Open
Abstract
Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-CRISPR-associated (Cas) systems have revolutionized modern molecular biology. Numerous types of these systems have been discovered to date. Many CRISPR-Cas systems have been used as a backbone for the development of potent research tools, with Cas9 being the most widespread. While most of the utilized systems are DNA-targeting, recently more and more attention is being gained by those that target RNA. Their ability to specifically recognize a given RNA sequence in an easily programmable way makes them ideal candidates for developing new research tools. In this review we summarize current knowledge on CRISPR-Cas systems which have been shown to target RNA molecules, that is type III (Csm/Cmr), type VI (Cas13), and type II (Cas9). We also present a list of available technologies based on these systems.
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24
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Rollie C, Chevallereau A, Watson BNJ, Chyou TY, Fradet O, McLeod I, Fineran PC, Brown CM, Gandon S, Westra ER. Targeting of temperate phages drives loss of type I CRISPR-Cas systems. Nature 2020; 578:149-153. [PMID: 31969710 PMCID: PMC7007301 DOI: 10.1038/s41586-020-1936-2] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Accepted: 11/25/2019] [Indexed: 01/27/2023]
Abstract
On infection of their host, temperate viruses that infect bacteria (bacteriophages; hereafter referred to as phages) enter either a lytic or a lysogenic cycle. The former results in lysis of bacterial cells and phage release (resulting in horizontal transmission), whereas lysogeny is characterized by the integration of the phage into the host genome, and dormancy (resulting in vertical transmission)1. Previous co-culture experiments using bacteria and mutants of temperate phages that are locked in the lytic cycle have shown that CRISPR-Cas systems can efficiently eliminate the invading phages2,3. Here we show that, when challenged with wild-type temperate phages (which can become lysogenic), type I CRISPR-Cas immune systems cannot eliminate the phages from the bacterial population. Furthermore, our data suggest that, in this context, CRISPR-Cas immune systems are maladaptive to the host, owing to the severe immunopathological effects that are brought about by imperfect matching of spacers to the integrated phage sequences (prophages). These fitness costs drive the loss of CRISPR-Cas from bacterial populations, unless the phage carries anti-CRISPR (acr) genes that suppress the immune system of the host. Using bioinformatics, we show that this imperfect targeting is likely to occur frequently in nature. These findings help to explain the patchy distribution of CRISPR-Cas immune systems within and between bacterial species, and highlight the strong selective benefits of phage-encoded acr genes for both the phage and the host under these circumstances.
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Affiliation(s)
- Clare Rollie
- ESI, Biosciences, University of Exeter, Penryn, UK.
| | | | | | - Te-Yuan Chyou
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
| | | | | | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Chris M Brown
- Department of Biochemistry, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Sylvain Gandon
- CEFE, Université de Montpellier, CNRS, EPHE, IRD, Université Paul Valéry Montpellier 3, Montpellier, France
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25
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Chevallereau A, Meaden S, van Houte S, Westra ER, Rollie C. The effect of bacterial mutation rate on the evolution of CRISPR-Cas adaptive immunity. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180094. [PMID: 30905293 PMCID: PMC6452272 DOI: 10.1098/rstb.2018.0094] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2018] [Indexed: 01/07/2023] Open
Abstract
CRISPR-Cas immune systems are present in around half of bacterial genomes. Given the specificity and adaptability of this immune mechanism, it is perhaps surprising that they are not more widespread. Recent insights into the requirement for specific host factors for the function of some CRISPR-Cas subtypes, as well as the negative epistasis between CRISPR-Cas and other host genes, have shed light on potential reasons for the partial distribution of this immune strategy in bacteria. In this study, we examined how mutations in the bacterial mismatch repair system, which are frequently observed in natural and clinical isolates and cause elevated host mutation rates, influence the evolution of CRISPR-Cas-mediated immunity. We found that hosts with a high mutation rate very rarely evolved CRISPR-based immunity to phage compared to wild-type hosts. We explored the reason for this effect and found that the higher frequency at which surface mutants pre-exist in the mutator host background causes them to rapidly become the dominant phenotype under phage infection. These findings suggest that natural variation in bacterial mutation rates may, therefore, influence the distribution of CRISPR-Cas adaptive immune systems. This article is part of a discussion meeting issue 'The ecology and evolution of prokaryotic CRISPR-Cas adaptive immune systems'.
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Affiliation(s)
| | | | | | - Edze R. Westra
- ESI and CEC, Biosciences, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9EZ, UK
| | - Clare Rollie
- ESI and CEC, Biosciences, University of Exeter, Penryn Campus, Penryn, Cornwall TR10 9EZ, UK
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26
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Ali Q. Non-conventional therapeutic technique to replace CRISPR bacteria from biofilm by inducible lysogen. JOURNAL OF BIOLOGICAL DYNAMICS 2018; 13:151-178. [PMID: 30295162 DOI: 10.1080/17513758.2018.1527958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 09/18/2018] [Indexed: 06/08/2023]
Abstract
Bacteriophage can be an effective means of regulating bacterial populations when conditions allow phage invasion of bacterial colonies. Phage can either infect and lyse a host cell, or insert their DNA into the host cell genome; the latter process is called lysogeny. The clustered regularly interspaced short palindromic repeat (CRISPR) system, linked with CRISPR-associated (Cas) genes, is a regulatory system present in a variety of bacteria which confers immunity against bacteriophage. Studies of the group behaviour of bacteria with CRISPR/Cas systems have provided evidence that CRISPR in lysogenized bacteria can cause an inability to form biofilm. This allows CRISPR-immune bacteria in biofilms to effectively resist phage therapy. Our recent work has described a potential therapeutic technique to eradicate CRISPR-immune bacteria from a biofilm by a continuous influx of lysogens carrying an identical phage sequence. However, this model predicted that the CRISPR-immune population could persist for long times before eradication. Our current focus is on the use of diverse lysogens against CRISPR-capable bacterial populations. The goal of this work is to find a suitable strategy which can eradicate bacteria with a CRISPR system through the influx of finite amounts of distinct lysogens over fixed intervals.
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Affiliation(s)
- Qasim Ali
- a Department of Mathematics, North Carolina State University , Raleigh , NC , USA
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Faure G, Makarova KS, Koonin EV. CRISPR-Cas: Complex Functional Networks and Multiple Roles beyond Adaptive Immunity. J Mol Biol 2018; 431:3-20. [PMID: 30193985 DOI: 10.1016/j.jmb.2018.08.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 08/28/2018] [Accepted: 08/29/2018] [Indexed: 01/26/2023]
Abstract
CRISPR-Cas is a prokaryotic adaptive immune system that functions by incorporating fragments of foreign DNA into CRISPR arrays. The arrays containing spacers derived from foreign DNA are transcribed, and the transcripts are processed to generate spacer-containing mature CRISPR-RNAs that are employed as guides to specifically recognize and cleave the DNA or RNA of the cognate parasitic genetic elements. The CRISPR-Cas systems show remarkable complexity and diversity of molecular organization and appear to be involved in various cellular functions that are distinct from, even if connected to, adaptive immunity. In this review, we discuss some of such functional links of CRISPR-Cas systems including their effect on horizontal gene transfer that can be either inhibitory or stimulatory, connections between CRISPR-Cas and DNA repair systems as well as programmed cell death and signal transduction mechanisms, and potential role of CRISPR-Cas in transposon integration and plasmid maintenance. The interplay between the primary function of CRISPR-Cas as an adaptive immunity mechanism and these other roles defines the richness of the biological effects of these systems and affects their spread among bacteria and archaea.
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Affiliation(s)
- Guilhem Faure
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA.
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28
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Rouillon C, Athukoralage JS, Graham S, Grüschow S, White MF. Control of cyclic oligoadenylate synthesis in a type III CRISPR system. eLife 2018; 7:36734. [PMID: 29963983 PMCID: PMC6053304 DOI: 10.7554/elife.36734] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 07/01/2018] [Indexed: 12/15/2022] Open
Abstract
The CRISPR system for prokaryotic adaptive immunity provides RNA-mediated protection from viruses and mobile genetic elements. When viral RNA transcripts are detected, type III systems adopt an activated state that licenses DNA interference and synthesis of cyclic oligoadenylate (cOA). cOA activates nucleases and transcription factors that orchestrate the antiviral response. We demonstrate that cOA synthesis is subject to tight temporal control, commencing on target RNA binding, and is deactivated rapidly as target RNA is cleaved and dissociates. Mismatches in the target RNA are well tolerated and still activate the cyclase domain, except when located close to the 3' end of the target. Phosphorothioate modification reduces target RNA cleavage and stimulates cOA production. The 'RNA shredding' activity originally ascribed to type III systems may thus be a reflection of an exquisite mechanism for control of the Cas10 subunit, rather than a direct antiviral defence.
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Affiliation(s)
- Christophe Rouillon
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Januka S Athukoralage
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Shirley Graham
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Sabine Grüschow
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, United Kingdom
| | - Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, United Kingdom
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29
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Zhu Y, Klompe SE, Vlot M, van der Oost J, Staals RHJ. Shooting the messenger: RNA-targetting CRISPR-Cas systems. Biosci Rep 2018; 38:BSR20170788. [PMID: 29748239 PMCID: PMC6013697 DOI: 10.1042/bsr20170788] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 05/02/2018] [Accepted: 05/04/2018] [Indexed: 12/26/2022] Open
Abstract
Since the discovery of CRISPR-Cas (Clustered Regularly Interspaced Short Palindromic Repeats, CRISPR-associated genes) immune systems, astonishing progress has been made on revealing their mechanistic foundations. Due to the immense potential as genome engineering tools, research has mainly focussed on a subset of Cas nucleases that target DNA. In addition, however, distinct types of RNA-targetting CRISPR-Cas systems have been identified. The focus of this review will be on the interference mechanisms of the RNA targetting type III and type VI CRISPR-Cas systems, their biological relevance and their potential for applications.
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Affiliation(s)
- Yifan Zhu
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, The Netherlands
| | - Sanne E Klompe
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, The Netherlands
| | - Marnix Vlot
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, The Netherlands
| | - John van der Oost
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, The Netherlands
| | - Raymond H J Staals
- Laboratory of Microbiology, Department of Agrotechnology and Food Sciences, Wageningen University, Wageningen 6708 WE, The Netherlands
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30
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Hullahalli K, Rodrigues M, Nguyen UT, Palmer K. An Attenuated CRISPR-Cas System in Enterococcus faecalis Permits DNA Acquisition. mBio 2018; 9:e00414-18. [PMID: 29717009 PMCID: PMC5930301 DOI: 10.1128/mbio.00414-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 03/28/2018] [Indexed: 12/13/2022] Open
Abstract
Antibiotic-resistant bacteria are critical public health concerns. Among the prime causative factors for the spread of antibiotic resistance is horizontal gene transfer (HGT). A useful model organism for investigating the relationship between HGT and antibiotic resistance is the opportunistic pathogen Enterococcus faecalis, since the species possesses highly conjugative plasmids that readily disseminate antibiotic resistance genes and virulence factors in nature. Unlike many commensal E. faecalis strains, the genomes of multidrug-resistant (MDR) E. faecalis clinical isolates are enriched for mobile genetic elements (MGEs) and lack clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein (Cas) genome defense systems. CRISPR-Cas systems cleave foreign DNA in a programmable, sequence-specific manner and are disadvantageous for MGE-derived genome expansion. An unexplored facet of CRISPR biology in E. faecalis is that MGEs that are targeted by native CRISPR-Cas systems can be maintained transiently. Here, we investigate the basis for this "CRISPR tolerance." We observe that E. faecalis can maintain self-targeting constructs that direct Cas9 to cleave the chromosome, but at a fitness cost. Interestingly, DNA repair genes were not upregulated during self-targeting, but integrated prophages were strongly induced. We determined that low cas9 expression contributes to this transient nonlethality and used this knowledge to develop a robust CRISPR-assisted genome-editing scheme. Our results suggest that E. faecalis has maximized the potential for DNA acquisition by attenuating its CRISPR machinery, thereby facilitating the acquisition of potentially beneficial MGEs that may otherwise be restricted by genome defense.IMPORTANCE CRISPR-Cas has provided a powerful toolkit to manipulate bacteria, resulting in improved genetic manipulations and novel antimicrobials. These powerful applications rely on the premise that CRISPR-Cas chromosome targeting, which leads to double-stranded DNA breaks, is lethal. In this study, we show that chromosomal CRISPR targeting in Enterococcus faecalis is transiently nonlethal. We uncover novel phenotypes associated with this "CRISPR tolerance" and, after determining its genetic basis, develop a genome-editing platform in E. faecalis with negligible off-target effects. Our findings reveal a novel strategy exploited by a bacterial pathogen to cope with CRISPR-induced conflicts to more readily accept DNA, and our robust CRISPR editing platform will help simplify genetic modifications in this organism.
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Affiliation(s)
- Karthik Hullahalli
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Marinelle Rodrigues
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Uyen Thy Nguyen
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Kelli Palmer
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
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31
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Klompe SE, Sternberg SH. Harnessing "A Billion Years of Experimentation": The Ongoing Exploration and Exploitation of CRISPR-Cas Immune Systems. CRISPR J 2018; 1:141-158. [PMID: 31021200 PMCID: PMC6636882 DOI: 10.1089/crispr.2018.0012] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The famed physicist-turned-biologist, Max Delbrück, once remarked that, for physicists, "the field of bacterial viruses is a fine playground for serious children who ask ambitious questions." Early discoveries in that playground helped establish molecular genetics, and half a century later, biologists delving into the same field have ushered in the era of precision genome engineering. The focus has of course shifted-from bacterial viruses and their mechanisms of infection to the bacterial hosts and their mechanisms of immunity-but it is the very same evolutionary arms race that continues to awe and inspire researchers worldwide. In this review, we explore the remarkable diversity of CRISPR-Cas adaptive immune systems, describe the molecular components that mediate nucleic acid targeting, and outline the use of these RNA-guided machines for biotechnology applications. CRISPR-Cas research has yielded far more than just Cas9-based genome-editing tools, and the wide-reaching, innovative impacts of this fascinating biological playground are sure to be felt for years to come.
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Affiliation(s)
- Sanne E Klompe
- Department of Biochemistry and Molecular Biophysics, Columbia University , New York, New York
| | - Samuel H Sternberg
- Department of Biochemistry and Molecular Biophysics, Columbia University , New York, New York
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