1
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Smalakyte D, Ruksenaite A, Sasnauskas G, Tamulaitiene G, Tamulaitis G. Filament formation activates protease and ring nuclease activities of CRISPR Lon-SAVED. Mol Cell 2024:S1097-2765(24)00735-4. [PMID: 39362215 DOI: 10.1016/j.molcel.2024.09.002] [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: 04/18/2024] [Revised: 07/22/2024] [Accepted: 09/04/2024] [Indexed: 10/05/2024]
Abstract
To combat phage infection, type III CRISPR-Cas systems utilize cyclic oligoadenylates (cAn) signaling to activate various auxiliary effectors, including the CRISPR-associated Lon-SAVED protease CalpL, which forms a tripartite effector system together with an anti-σ factor, CalpT, and an ECF-like σ factor, CalpS. Here, we report the characterization of the Candidatus Cloacimonas acidaminovorans CalpL-CalpT-CalpS. We demonstrate that cA4 binding triggers CalpL filament formation and activates it to cleave CalpT within the CalpT-CalpS dimer. This cleavage exposes the CalpT C-degron, which targets it for further degradation by cellular proteases. Consequently, CalpS is released to bind to RNA polymerase, causing growth arrest in E. coli. Furthermore, the CalpL-CalpT-CalpS system is regulated by the SAVED domain of CalpL, which is a ring nuclease that cleaves cA4 in a sequential three-step mechanism. These findings provide key mechanistic details for the activation, proteolytic events, and regulation of the signaling cascade in the type III CRISPR-Cas immunity.
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Affiliation(s)
- Dalia Smalakyte
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio av. 7, 10257 Vilnius, Lithuania
| | - Audrone Ruksenaite
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio av. 7, 10257 Vilnius, Lithuania
| | - Giedrius Sasnauskas
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio av. 7, 10257 Vilnius, Lithuania
| | - Giedre Tamulaitiene
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio av. 7, 10257 Vilnius, Lithuania
| | - Gintautas Tamulaitis
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Saulėtekio av. 7, 10257 Vilnius, Lithuania.
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2
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Zhang D, Du L, Gao H, Yuan C, Lin Z. Structural insight into the Csx1-Crn2 fusion self-limiting ribonuclease of type III CRISPR system. Nucleic Acids Res 2024; 52:8419-8430. [PMID: 38967023 PMCID: PMC11317161 DOI: 10.1093/nar/gkae569] [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: 04/02/2024] [Revised: 06/14/2024] [Accepted: 06/25/2024] [Indexed: 07/06/2024] Open
Abstract
In the type III CRISPR system, cyclic oligoadenylate (cOA) molecules act as second messengers, activating various promiscuous ancillary nucleases that indiscriminately degrade host and viral DNA/RNA. Conversely, ring nucleases, by specifically cleaving cOA molecules, function as off-switches to protect host cells from dormancy or death, and allow viruses to counteract immune responses. The fusion protein Csx1-Crn2, combining host ribonuclease with viral ring nuclease, represents a unique self-limiting ribonuclease family. Here, we describe the structures of Csx1-Crn2 from the organism of Marinitoga sp., in both its full-length and truncated forms, as well as in complex with cA4. We show that Csx1-Crn2 operates as a homo-tetramer, a configuration crucial for preserving the structural integrity of the HEPN domain and ensuring effective ssRNA cleavage. The binding of cA4 to the CARF domain triggers significant conformational changes across the CARF, HTH, and into the HEPN domains, leading the two R-X4-6-H motifs to form a composite catalytic site. Intriguingly, an acetate ion was found to bind at this composite site by mimicking the scissile phosphate. Further molecular docking analysis reveals that the HEPN domain can accommodate a single ssRNA molecule involving both R-X4-6-H motifs, underscoring the importance of HEPN domain dimerization for its activation.
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Affiliation(s)
- Danping Zhang
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Liyang Du
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Haishan Gao
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang, China
- School of Life Sciences, Westlake University, Hangzhou, Zhejiang, China
| | - Cai Yuan
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, China
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
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3
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Hoikkala V, Graham S, White MF. Bioinformatic analysis of type III CRISPR systems reveals key properties and new effector families. Nucleic Acids Res 2024; 52:7129-7141. [PMID: 38808661 PMCID: PMC11229360 DOI: 10.1093/nar/gkae462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Revised: 05/13/2024] [Accepted: 05/16/2024] [Indexed: 05/30/2024] Open
Abstract
Recognition of RNA from invading mobile genetic elements (MGE) prompts type III CRISPR systems to activate an HD nuclease domain and/or a nucleotide cyclase domain in the Cas10 subunit, eliciting an immune response. The cyclase domain can generate a range of nucleotide second messengers, which in turn activate a diverse family of ancillary effector proteins. These provide immunity by non-specific degradation of host and MGE nucleic acids or proteins, perturbation of membrane potentials, transcriptional responses, or the arrest of translation. The wide range of nucleotide activators and downstream effectors generates a complex picture that is gradually being resolved. Here, we carry out a global bioinformatic analysis of type III CRISPR loci in prokaryotic genomes, defining the relationships of Cas10 proteins and their ancillary effectors. Our study reveals that cyclic tetra-adenylate is by far the most common signalling molecule used and that many loci have multiple effectors. These typically share the same activator and may work synergistically to combat MGE. We propose four new candidate effector protein families and confirm experimentally that the Csm6-2 protein, a highly diverged, fused Csm6 effector, is a ribonuclease activated by cyclic hexa-adenylate.
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Affiliation(s)
- Ville Hoikkala
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Shirley Graham
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
| | - Malcolm F White
- School of Biology, University of St Andrews, St Andrews KY16 9ST, UK
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4
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Fuentenebro Navas D, Steens JA, de Lannoy C, Noordijk B, Pfeffer M, de Ridder D, H.J. Staals R, Schmid S. Nanopores Reveal the Stoichiometry of Single Oligoadenylates Produced by Type III CRISPR-Cas. ACS NANO 2024; 18:16505-16515. [PMID: 38875527 PMCID: PMC11223493 DOI: 10.1021/acsnano.3c11769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 05/27/2024] [Accepted: 06/05/2024] [Indexed: 06/16/2024]
Abstract
Cyclic oligoadenylates (cOAs) are small second messenger molecules produced by the type III CRISPR-Cas system as part of the prokaryotic immune response. The role of cOAs is to allosterically activate downstream effector proteins that induce dormancy or cell death, and thus abort viral spread through the population. Interestingly, different type III systems have been reported to utilize different cOA stoichiometries (with 3 to 6 adenylate monophosphates). However, so far, their characterization has only been possible in bulk and with sophisticated equipment, while a portable assay with single-molecule resolution has been lacking. Here, we demonstrate the label-free detection of single cOA molecules using a simple protein nanopore assay. It sensitively identifies the stoichiometry of individual cOA molecules and their mixtures from synthetic and enzymatic origin. To achieve this, we trained a convolutional neural network (CNN) and validated it with a series of experiments on mono- and polydisperse cOA samples. Ultimately, we determined the stoichiometric composition of cOAs produced enzymatically by the CRISPR type III-A and III-B variants of Thermus thermophilus and confirmed the results by liquid chromatography-mass spectroscopy (LC-MS). Interestingly, both variants produce cOAs of nearly identical composition (within experimental uncertainties), and we discuss the biological implications of this finding. The presented nanopore-CNN workflow with single cOA resolution can be adapted to many other signaling molecules (including eukaryotic ones), and it may be integrated into portable handheld devices with potential point-of-care applications.
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Affiliation(s)
- David Fuentenebro Navas
- Laboratory
of Biophysics, Wageningen University and
Research, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Jurre A. Steens
- Laboratory
of Microbiology, Wageningen University and
Research, Stippeneng
4, 6708WE Wageningen, The Netherlands
| | - Carlos de Lannoy
- Bioinformatics
Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
- Department
of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Ben Noordijk
- Bioinformatics
Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Michael Pfeffer
- Department
of Chemistry, University of Basel, Mattenstrasse 22, 4058 Basel, Switzerland
| | - Dick de Ridder
- Bioinformatics
Group, Wageningen University and Research, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
| | - Raymond H.J. Staals
- Laboratory
of Microbiology, Wageningen University and
Research, Stippeneng
4, 6708WE Wageningen, The Netherlands
| | - Sonja Schmid
- Laboratory
of Biophysics, Wageningen University and
Research, Stippeneng 4, 6708WE Wageningen, The Netherlands
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5
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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] [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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6
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Bell RT, Sahakyan H, Makarova KS, Wolf YI, Koonin EV. CoCoNuTs are a diverse subclass of Type IV restriction systems predicted to target RNA. eLife 2024; 13:RP94800. [PMID: 38739430 PMCID: PMC11090510 DOI: 10.7554/elife.94800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2024] Open
Abstract
A comprehensive census of McrBC systems, among the most common forms of prokaryotic Type IV restriction systems, followed by phylogenetic analysis, reveals their enormous abundance in diverse prokaryotes and a plethora of genomic associations. We focus on a previously uncharacterized branch, which we denote coiled-coil nuclease tandems (CoCoNuTs) for their salient features: the presence of extensive coiled-coil structures and tandem nucleases. The CoCoNuTs alone show extraordinary variety, with three distinct types and multiple subtypes. All CoCoNuTs contain domains predicted to interact with translation system components, such as OB-folds resembling the SmpB protein that binds bacterial transfer-messenger RNA (tmRNA), YTH-like domains that might recognize methylated tmRNA, tRNA, or rRNA, and RNA-binding Hsp70 chaperone homologs, along with RNases, such as HEPN domains, all suggesting that the CoCoNuTs target RNA. Many CoCoNuTs might additionally target DNA, via McrC nuclease homologs. Additional restriction systems, such as Type I RM, BREX, and Druantia Type III, are frequently encoded in the same predicted superoperons. In many of these superoperons, CoCoNuTs are likely regulated by cyclic nucleotides, possibly, RNA fragments with cyclic termini, that bind associated CARF (CRISPR-Associated Rossmann Fold) domains. We hypothesize that the CoCoNuTs, together with the ancillary restriction factors, employ an echeloned defense strategy analogous to that of Type III CRISPR-Cas systems, in which an immune response eliminating virus DNA and/or RNA is launched first, but then, if it fails, an abortive infection response leading to PCD/dormancy via host RNA cleavage takes over.
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Affiliation(s)
- Ryan T Bell
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Harutyun Sahakyan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Kira S Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Yuri I Wolf
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
| | - Eugene V Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of HealthBethesdaUnited States
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7
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Irmisch P, Mogila I, Samatanga B, Tamulaitis G, Seidel R. Retention of the RNA ends provides the molecular memory for maintaining the activation of the Csm complex. Nucleic Acids Res 2024; 52:3896-3910. [PMID: 38340341 DOI: 10.1093/nar/gkae080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/23/2024] [Accepted: 02/07/2024] [Indexed: 02/12/2024] Open
Abstract
The type III CRISPR-Cas effector complex Csm functions as a molecular Swiss army knife that provides multilevel defense against foreign nucleic acids. The coordinated action of three catalytic activities of the Csm complex enables simultaneous degradation of the invader's RNA transcripts, destruction of the template DNA and synthesis of signaling molecules (cyclic oligoadenylates cAn) that activate auxiliary proteins to reinforce CRISPR-Cas defense. Here, we employed single-molecule techniques to connect the kinetics of RNA binding, dissociation, and DNA hydrolysis by the Csm complex from Streptococcus thermophilus. Although single-stranded RNA is cleaved rapidly (within seconds), dual-color FCS experiments and single-molecule TIRF microscopy revealed that Csm remains bound to terminal RNA cleavage products with a half-life of over 1 hour while releasing the internal RNA fragments quickly. Using a continuous fluorescent DNA degradation assay, we observed that RNA-regulated single-stranded DNase activity decreases on a similar timescale. These findings suggest that after fast target RNA cleavage the terminal RNA cleavage products stay bound within the Csm complex, keeping the Cas10 subunit activated for DNA destruction. Additionally, we demonstrate that during Cas10 activation, the complex remains capable of RNA turnover, i.e. of ongoing degradation of target RNA.
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Affiliation(s)
- Patrick Irmisch
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Irmantas Mogila
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Brighton Samatanga
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
| | - Gintautas Tamulaitis
- Institute of Biotechnology, Life Sciences Center, Vilnius University, Vilnius 10257, Lithuania
| | - Ralf Seidel
- Peter Debye Institute for Soft Matter Physics, University of Leipzig, Leipzig 04103, Germany
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8
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Grüschow S, McQuarrie S, Ackermann K, McMahon S, Bode B, Gloster T, White M. CRISPR antiphage defence mediated by the cyclic nucleotide-binding membrane protein Csx23. Nucleic Acids Res 2024; 52:2761-2775. [PMID: 38471818 PMCID: PMC11014256 DOI: 10.1093/nar/gkae167] [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: 12/01/2023] [Revised: 02/21/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
CRISPR-Cas provides adaptive immunity in prokaryotes. Type III CRISPR systems detect invading RNA and activate the catalytic Cas10 subunit, which generates a range of nucleotide second messengers to signal infection. These molecules bind and activate a diverse range of effector proteins that provide immunity by degrading viral components and/or by disturbing key aspects of cellular metabolism to slow down viral replication. Here, we focus on the uncharacterised effector Csx23, which is widespread in Vibrio cholerae. Csx23 provides immunity against plasmids and phage when expressed in Escherichia coli along with its cognate type III CRISPR system. The Csx23 protein localises in the membrane using an N-terminal transmembrane α-helical domain and has a cytoplasmic C-terminal domain that binds cyclic tetra-adenylate (cA4), activating its defence function. Structural studies reveal a tetrameric structure with a novel fold that binds cA4 specifically. Using pulse EPR, we demonstrate that cA4 binding to the cytoplasmic domain of Csx23 results in a major perturbation of the transmembrane domain, consistent with the opening of a pore and/or disruption of membrane integrity. This work reveals a new class of cyclic nucleotide binding protein and provides key mechanistic detail on a membrane-associated CRISPR effector.
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Affiliation(s)
- Sabine Grüschow
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - Stuart McQuarrie
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - Katrin Ackermann
- Biomedical Sciences Research Complex, School of Chemistry, Centre of Magnetic Resonance, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Stephen McMahon
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - Bela E Bode
- Biomedical Sciences Research Complex, School of Chemistry, Centre of Magnetic Resonance, University of St Andrews, St Andrews, Fife, KY16 9ST, UK
| | - Tracey M Gloster
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, Fife KY16 9ST, UK
| | - Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, St Andrews, Fife KY16 9ST, UK
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9
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Karneyeva K, Kolesnik M, Livenskyi A, Zgoda V, Zubarev V, Trofimova A, Artamonova D, Ispolatov Y, Severinov K. Interference Requirements of Type III CRISPR-Cas Systems from Thermus thermophilus. J Mol Biol 2024; 436:168448. [PMID: 38266982 DOI: 10.1016/j.jmb.2024.168448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2023] [Revised: 01/12/2024] [Accepted: 01/13/2024] [Indexed: 01/26/2024]
Abstract
Among the diverse prokaryotic adaptive immunity mechanisms, the Type III CRISPR-Cas systems are the most complex. The multisubunit Type III effectors recognize RNA targets complementary to CRISPR RNAs (crRNAs). Target recognition causes synthesis of cyclic oligoadenylates that activate downstream auxiliary effectors, which affect cell physiology in complex and poorly understood ways. Here, we studied the ability of III-A and III-B CRISPR-Cas subtypes from Thermus thermophilus to interfere with plasmid transformation. We find that for both systems, requirements for crRNA-target complementarity sufficient for interference depend on the target transcript abundance, with more abundant targets requiring shorter complementarity segments. This result and thermodynamic calculations indicate that Type III effectors bind their targets in a simple bimolecular reaction with more extensive crRNA-target base pairing compensating for lower target abundance. Since the targeted RNA used in our work is non-essential for either the host or the plasmid, the results also establish that a certain number of target-bound effector complexes must be present in the cell to interfere with plasmid establishment. For the more active III-A system, we determine the minimal length of RNA-duplex sufficient for interference and show that the position of this minimal duplex can vary within the effector. Finally, we show that the III-A immunity is dependent on the HD nuclease domain of the Cas10 subunit. Since this domain is absent from the III-B system the result implies that the T. thermophilus III-B system must elicit a more efficient cyclic oligoadenylate-dependent response to provide the immunity.
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Affiliation(s)
- Karyna Karneyeva
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Matvey Kolesnik
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Alexei Livenskyi
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia; Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119992, Russia
| | - Viktor Zgoda
- Institute of Biomedical Chemistry, Moscow 119435, Russia
| | - Vasiliy Zubarev
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Anna Trofimova
- Laboratory of Molecular Genetics of Microorganisms, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia
| | - Daria Artamonova
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Yaroslav Ispolatov
- Departamento de Física, Center for Interdisciplinary Research in Astrophysics and Space Science, Universidad de Santiago de Chile, Victor Jara 3493, Santiago, Chile
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10
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Li X, Han J, Yang J, Zhang H. The structural biology of type III CRISPR-Cas systems. J Struct Biol 2024; 216:108070. [PMID: 38395113 DOI: 10.1016/j.jsb.2024.108070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 02/19/2024] [Accepted: 02/19/2024] [Indexed: 02/25/2024]
Abstract
CRISPR-Cas system is an RNA-guided adaptive immune system widespread in bacteria and archaea. Among them, type III CRISPR-Cas systems are the most ancient throughout the CRISPR-Cas family, proving anti-phage defense through a crRNA-guided RNA targeting manner and possessing multiple enzymatic activities. Type III CRISPR-Cas systems comprise four typical members (type III-A to III-D) and two atypical members (type III-E and type III-F), providing immune defense through distinct mechanisms. Here, we delve into structural studies conducted on three well-characterized members: the type III-A, III-B, and III-E systems, provide an overview of the structural insights into the crRNA-guided target RNA cleavage, self/non-self discrimination, and the target RNA-dependent regulation of enzymatic subunits in the effector complex.
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Affiliation(s)
- Xuzichao Li
- State Key Laboratory of Experimental Hematology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jie Han
- Department of Anatomy and Histology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jie Yang
- State Key Laboratory of Experimental Hematology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Heng Zhang
- State Key Laboratory of Experimental Hematology, Key Laboratory of Immune Microenvironment and Disease (Ministry of Education), The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China.
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11
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Aviram N, Shilton AK, Lyn NG, Reis BS, Brivanlou A, Marraffini LA. The Cas10 nuclease activity relieves host dormancy to facilitate spacer acquisition and retention during type III-A CRISPR immunity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.11.579731. [PMID: 38405743 PMCID: PMC10888962 DOI: 10.1101/2024.02.11.579731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
A hallmark of CRISPR immunity is the acquisition of short viral DNA sequences, known as spacers, that are transcribed into guide RNAs to recognize complementary sequences. The staphylococcal type III-A CRISPR-Cas system uses guide RNAs to locate viral transcripts and start a response that displays two mechanisms of immunity. When immunity is triggered by an early-expressed phage RNA, degradation of viral ssDNA can cure the host from infection. In contrast, when the RNA guide targets a late-expressed transcript, defense requires the activity of Csm6, a non-specific RNase. Here we show that Csm6 triggers a growth arrest of the host that provides immunity at the population level which hinders viral propagation to allow the replication of non-infected cells. We demonstrate that this mechanism leads to defense against not only the target phage but also other viruses present in the population that fail to replicate in the arrested cells. On the other hand, dormancy limits the acquisition and retention of spacers that trigger it. We found that the ssDNase activity of type III-A systems is required for the re-growth of a subset of the arrested cells, presumably through the degradation of the phage DNA, ending target transcription and inactivating the immune response. Altogether, our work reveals a built-in mechanism within type III-A CRISPR-Cas systems that allows the exit from dormancy needed for the subsistence of spacers that provide broad-spectrum immunity.
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Affiliation(s)
- Naama Aviram
- Laboratory of Bacteriology, the Rockefeller University, 1230 York Ave, New York, NY 10065, USA
| | - Amanda K Shilton
- Laboratory of Bacteriology, the Rockefeller University, 1230 York Ave, New York, NY 10065, USA
| | - Nia G Lyn
- Laboratory of Bacteriology, the Rockefeller University, 1230 York Ave, New York, NY 10065, USA
| | - Bernardo S Reis
- Laboratory of Mucosal Immunology, the Rockefeller University, 1230 York Ave, New York, NY 10065, USA
| | - Amir Brivanlou
- Laboratory of Bacteriology, the Rockefeller University, 1230 York Ave, New York, NY 10065, USA
| | - Luciano A Marraffini
- Laboratory of Bacteriology, the Rockefeller University, 1230 York Ave, New York, NY 10065, USA
- Howard Hughes Medical Institute, The Rockefeller University, 1230 York Ave, New York, NY 10065, USA
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12
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Bell RT, Sahakyan H, Makarova KS, Wolf YI, Koonin EV. CoCoNuTs: A diverse subclass of Type IV restriction systems predicted to target RNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.07.31.551357. [PMID: 37790407 PMCID: PMC10542128 DOI: 10.1101/2023.07.31.551357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
A comprehensive census of McrBC systems, among the most common forms of prokaryotic Type IV restriction systems, followed by phylogenetic analysis, reveals their enormous abundance in diverse prokaryotes and a plethora of genomic associations. We focus on a previously uncharacterized branch, which we denote CoCoNuTs (coiled-coil nuclease tandems) for their salient features: the presence of extensive coiled-coil structures and tandem nucleases. The CoCoNuTs alone show extraordinary variety, with 3 distinct types and multiple subtypes. All CoCoNuTs contain domains predicted to interact with translation system components, such as OB-folds resembling the SmpB protein that binds bacterial transfer-messenger RNA (tmRNA), YTH-like domains that might recognize methylated tmRNA, tRNA, or rRNA, and RNA-binding Hsp70 chaperone homologs, along with RNases, such as HEPN domains, all suggesting that the CoCoNuTs target RNA. Many CoCoNuTs might additionally target DNA, via McrC nuclease homologs. Additional restriction systems, such as Type I RM, BREX, and Druantia Type III, are frequently encoded in the same predicted superoperons. In many of these superoperons, CoCoNuTs are likely regulated by cyclic nucleotides, possibly, RNA fragments with cyclic termini, that bind associated CARF (CRISPR-Associated Rossmann Fold) domains. We hypothesize that the CoCoNuTs, together with the ancillary restriction factors, employ an echeloned defense strategy analogous to that of Type III CRISPR-Cas systems, in which an immune response eliminating virus DNA and/or RNA is launched first, but then, if it fails, an abortive infection response leading to PCD/dormancy via host RNA cleavage takes over.
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Affiliation(s)
- Ryan T. Bell
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Harutyun Sahakyan
- 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
| | - Yuri I. Wolf
- 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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13
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Jungfer K, Sigg A, Jinek M. Substrate selectivity and catalytic activation of the type III CRISPR ancillary nuclease Can2. Nucleic Acids Res 2024; 52:462-473. [PMID: 38033326 PMCID: PMC10783487 DOI: 10.1093/nar/gkad1102] [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: 07/26/2023] [Revised: 10/26/2023] [Accepted: 11/09/2023] [Indexed: 12/02/2023] Open
Abstract
Type III CRISPR-Cas systems provide adaptive immunity against foreign mobile genetic elements through RNA-guided interference. Sequence-specific recognition of RNA targets by the type III effector complex triggers the generation of cyclic oligoadenylate (cOA) second messengers that activate ancillary effector proteins, thus reinforcing the host immune response. The ancillary nuclease Can2 is activated by cyclic tetra-AMP (cA4); however, the mechanisms underlying cA4-mediated activation and substrate selectivity remain elusive. Here we report crystal structures of Thermoanaerobacter brockii Can2 (TbrCan2) in substrate- and product-bound complexes. We show that TbrCan2 is a single strand-selective DNase and RNase that binds substrates via a conserved SxTTS active site motif, and reveal molecular interactions underpinning its sequence preference for CA dinucleotides. Furthermore, we identify a molecular interaction relay linking the cA4 binding site and the nuclease catalytic site to enable divalent metal cation coordination and catalytic activation. These findings provide key insights into the molecular mechanisms of Can2 nucleases in type III CRISPR-Cas immunity and may guide their technological development for nucleic acid detection applications.
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Affiliation(s)
- Kenny Jungfer
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Annina Sigg
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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14
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Stella G, Marraffini L. Type III CRISPR-Cas: beyond the Cas10 effector complex. Trends Biochem Sci 2024; 49:28-37. [PMID: 37949766 PMCID: PMC10844953 DOI: 10.1016/j.tibs.2023.10.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/06/2023] [Accepted: 10/13/2023] [Indexed: 11/12/2023]
Abstract
Type III CRISPR-Cas loci encode some of the most abundant, yet complex, immune systems of prokaryotes. They are composed of a Cas10 complex that uses an RNA guide to recognize transcripts from bacteriophage and plasmid invaders. Target recognition triggers three activities within this complex: ssDNA degradation, synthesis of cyclic oligoadenylates (cOA) that act as second messengers to activate CARF-domain effectors, and cleavage of target RNA. This review covers recent research in type III CRISPR-Cas systems that looked beyond the activity of the canonical Cas10 complexes towards: (i) ancillary nucleases and understanding how they provide defense by sensing cOA molecules; (ii) ring nucleases and their role in regulating cOA production; and (iii) CRISPR-associated proteases, including the function of the Craspase complex in a transcriptional response to phage infection.
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Affiliation(s)
- Gianna Stella
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA; Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medical College, Rockefeller University and Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA.
| | - Luciano Marraffini
- Laboratory of Bacteriology, The Rockefeller University, New York, NY 10065, USA; Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA.
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15
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Du L, Zhu Q, Lin Z. Molecular mechanism of allosteric activation of the CRISPR ribonuclease Csm6 by cyclic tetra-adenylate. EMBO J 2024; 43:304-315. [PMID: 38177499 PMCID: PMC10897365 DOI: 10.1038/s44318-023-00017-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/16/2023] [Accepted: 11/27/2023] [Indexed: 01/06/2024] Open
Abstract
Type III CRISPR systems are innate immune systems found in bacteria and archaea, which produce cyclic oligoadenylate (cOA) second messengers in response to viral infections. In these systems, Csm6 proteins serve as ancillary nucleases that degrade single-stranded RNA (ssRNA) upon activation by cOA. In addition, Csm6 proteins also possess cOA-degrading activity as an intrinsic off-switch to avoid degradation of host RNA and DNA that would eventually lead to cell dormancy or cell death. Here, we present the crystal structures of Thermus thermophilus (Tt) Csm6 alone, and in complex with cyclic tetra-adenylate (cA4) in both pre- and post-cleavage states. These structures establish the molecular basis of the long-range allosteric activation of TtCsm6 ribonuclease by cA4. cA4 binding induces significant conformational changes, including closure of the CARF domain, dimerization of the HTH domain, and reorganization of the R-X4-6-H motif within the HEPN domain. The cleavage of cA4 by the CARF domain restores each domain to a conformation similar to its apo state. Furthermore, we have identified hyperactive TtCsm6 variants that exhibit sustained cA4-activated RNase activity, showing great promise for their applications in genome editing and diagnostics.
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Affiliation(s)
- Liyang Du
- College of Chemistry, Fuzhou University, 350108, Fuzhou, China
| | - Qinwei Zhu
- College of Chemistry, Fuzhou University, 350108, Fuzhou, China
| | - Zhonghui Lin
- College of Chemistry, Fuzhou University, 350108, Fuzhou, China.
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16
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Baca CF, Yu Y, Rostøl JT, Majumder P, Patel DJ, Marraffini LA. The CRISPR effector Cam1 mediates membrane depolarization for phage defence. Nature 2024; 625:797-804. [PMID: 38200316 PMCID: PMC10808066 DOI: 10.1038/s41586-023-06902-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 11/27/2023] [Indexed: 01/12/2024]
Abstract
Prokaryotic type III CRISPR-Cas systems provide immunity against viruses and plasmids using CRISPR-associated Rossman fold (CARF) protein effectors1-5. Recognition of transcripts of these invaders with sequences that are complementary to CRISPR RNA guides leads to the production of cyclic oligoadenylate second messengers, which bind CARF domains and trigger the activity of an effector domain6,7. Whereas most effectors degrade host and invader nucleic acids, some are predicted to contain transmembrane helices without an enzymatic function. Whether and how these CARF-transmembrane helix fusion proteins facilitate the type III CRISPR-Cas immune response remains unknown. Here we investigate the role of cyclic oligoadenylate-activated membrane protein 1 (Cam1) during type III CRISPR immunity. Structural and biochemical analyses reveal that the CARF domains of a Cam1 dimer bind cyclic tetra-adenylate second messengers. In vivo, Cam1 localizes to the membrane, is predicted to form a tetrameric transmembrane pore, and provides defence against viral infection through the induction of membrane depolarization and growth arrest. These results reveal that CRISPR immunity does not always operate through the degradation of nucleic acids, but is instead mediated via a wider range of cellular responses.
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Affiliation(s)
- Christian F Baca
- Laboratory of Bacteriology, The Rockefeller University, New York, NY, USA
- Tri-Institutional PhD Program in Chemical Biology, Weill Cornell Medical College, Rockefeller University and Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - You Yu
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Jakob T Rostøl
- Laboratory of Bacteriology, The Rockefeller University, New York, NY, USA
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, London, UK
| | - Puja Majumder
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Dinshaw J Patel
- Structural Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.
| | - Luciano A Marraffini
- Laboratory of Bacteriology, The Rockefeller University, New York, NY, USA.
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY, USA.
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17
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Lin J, Alfastsen L, Bhoobalan-Chitty Y, Peng X. Molecular basis for inhibition of type III-B CRISPR-Cas by an archaeal viral anti-CRISPR protein. Cell Host Microbe 2023; 31:1837-1849.e5. [PMID: 37909049 DOI: 10.1016/j.chom.2023.10.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 06/03/2023] [Accepted: 10/04/2023] [Indexed: 11/02/2023]
Abstract
Despite a wide presence of type III clustered regularly interspaced short palindromic repeats, CRISPR-associated (CRISPR-Cas) in archaea and bacteria, very few anti-CRISPR (Acr) proteins inhibiting type III immunity have been identified, and even less is known about their inhibition mechanism. Here, we present the discovery of a type III CRISPR-Cas inhibitor, AcrIIIB2, encoded by Sulfolobus virus S. islandicus rod-shaped virus 3 (SIRV3). AcrIIIB2 inhibits type III-B CRISPR-Cas immune response to protospacers encoded in middle/late-expressed viral genes. Investigation of the interactions between S. islandicus type III-B CRISPR-Cas Cmr-α-related proteins and AcrIIIB2 reveals that the Acr does not bind to Csx1 but rather interacts with the Cmr-α effector complex. Furthermore, in vitro assays demonstrate that AcrIIIB2 can block the dissociation of cleaved target RNA from the Cmr-α complex, thereby inhibiting the Cmr-α turnover, thus preventing host cellular dormancy and further viral genome degradation by the type III-B CRISPR-Cas immunity.
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Affiliation(s)
- Jinzhong Lin
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | - Lauge Alfastsen
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark
| | | | - Xu Peng
- Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200 Copenhagen N, Denmark.
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18
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McQuarrie S, Athukoralage JS, McMahon SA, Graham S, Ackermann K, Bode BE, White MF, Gloster TM. Activation of Csm6 ribonuclease by cyclic nucleotide binding: in an emergency, twist to open. Nucleic Acids Res 2023; 51:10590-10605. [PMID: 37747760 DOI: 10.1093/nar/gkad739] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/23/2023] [Accepted: 09/11/2023] [Indexed: 09/26/2023] Open
Abstract
Type III CRISPR systems synthesize cyclic oligoadenylate (cOA) second messengers as part of a multi-faceted immune response against invading mobile genetic elements (MGEs). cOA activates non-specific CRISPR ancillary defence nucleases to create a hostile environment for MGE replication. Csm6 ribonucleases bind cOA using a CARF (CRISPR-associated Rossmann Fold) domain, resulting in activation of a fused HEPN (Higher Eukaryotes and Prokaryotes Nucleotide binding) ribonuclease domain. Csm6 enzymes are widely used in a new generation of diagnostic assays for the detection of specific nucleic acid species. However, the activation mechanism is not fully understood. Here we characterised the cyclic hexa-adenylate (cA6) activated Csm6' ribonuclease from the industrially important bacterium Streptococcus thermophilus. Crystal structures of Csm6' in the inactive and cA6 bound active states illuminate the conformational changes which trigger mRNA destruction. Upon binding of cA6, there is a close to 60° rotation between the CARF and HEPN domains, which causes the 'jaws' of the HEPN domain to open and reposition active site residues. Key to this transition is the 6H domain, a right-handed solenoid domain connecting the CARF and HEPN domains, which transmits the conformational changes for activation.
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Affiliation(s)
- Stuart McQuarrie
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Januka S Athukoralage
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Stephen A McMahon
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Shirley Graham
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Katrin Ackermann
- Biomedical Sciences Research Complex, School of Chemistry, Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Bela E Bode
- Biomedical Sciences Research Complex, School of Chemistry, Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Malcolm F White
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
| | - Tracey M Gloster
- Biomedical Sciences Research Complex, School of Biology, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK
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19
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Wang L, Zhang L. The arms race between bacteria CBASS and bacteriophages. Front Immunol 2023; 14:1224341. [PMID: 37575224 PMCID: PMC10419184 DOI: 10.3389/fimmu.2023.1224341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/06/2023] [Indexed: 08/15/2023] Open
Abstract
The Bacterial Cyclic oligonucleotide-Based Anti-phage Signaling System (CBASS) is an innate immune system that induces cell suicide to defend against phage infections. This system relies on cGAS/DncV-like nucleotidyltransferases (CD-NTase) to synthesize cyclic oligonucleotides (cOs) and CD-NTase-associated proteins (Caps) to execute cell death through DNA cleavage, membrane damage, and NAD depletion, thereby inhibiting phage replication. Ancillary proteins expressed in CBASS, in combination with CD-NTase, ensure the normal synthesis of cOs and prepare CD-NTase for full activation by binding to phage genomes, proteins, or other unknown products. To counteract cell death induced by CBASS, phage genes encode immune evasion proteins that curb Cap recognition of cOs, allowing for phage replication, assembly, and propagation in bacterial cells. This review provides a comprehensive understanding of CBASS immunity, comparing it with different bacterial immune systems and highlighting the interplay between CBASS and phage. Additionally, it explores similar immune escape methods based on shared proteins and action mechanisms between prokaryotic and eukaryotic viruses.
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Affiliation(s)
- Lan Wang
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
| | - Leiliang Zhang
- Department of Clinical Laboratory Medicine, The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
- Medical Science and Technology Innovation Center, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
- Department of Pathogen Biology, School of Clinical and Basic Medical Sciences, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, China
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20
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Chen Y, Zeng Z, She Q, Han W. The abortive infection functions of CRISPR-Cas and Argonaute. Trends Microbiol 2023; 31:405-418. [PMID: 36463018 DOI: 10.1016/j.tim.2022.11.005] [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: 09/15/2022] [Revised: 11/08/2022] [Accepted: 11/15/2022] [Indexed: 12/03/2022]
Abstract
CRISPR-Cas and prokaryotic Argonaute (pAgo) are nucleic acid (NA)-guided defense systems that protect prokaryotes against the invasion of mobile genetic elements. Previous studies established that they are directed by NA fragments (guides) to recognize invading complementary NA (targets), and that they cleave the targets to silence the invaders. Nevertheless, growing evidence indicates that many CRISPR-Cas and pAgo systems exploit the abortive infection (Abi) strategy to confer immunity. The CRISPR-Cas and pAgo Abi systems typically sense invaders using the NA recognition ability and activate various toxic effectors to kill the infected cells to prevent the invaders from spreading. This review summarizes the diverse mechanisms of these CRISPR-Cas and pAgo systems, and highlights their critical roles in the arms race between microbes and invaders.
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Affiliation(s)
- Yu Chen
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Hubei Hongshan Laboratory, Huazhong Agricultural University, 430070 Wuhan, China
| | - Zhifeng Zeng
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Hubei Hongshan Laboratory, Huazhong Agricultural University, 430070 Wuhan, China
| | - Qunxin She
- CRISPR and Archaea Biology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Binhai Road 72, Jimo, 266237, Qingdao, China
| | - Wenyuan Han
- State Key Laboratory of Agricultural Microbiology and College of Life Science and Technology, Hubei Hongshan Laboratory, Huazhong Agricultural University, 430070 Wuhan, China.
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21
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Du L, Zhang D, Luo Z, Lin Z. Molecular basis of stepwise cyclic tetra-adenylate cleavage by the type III CRISPR ring nuclease Crn1/Sso2081. Nucleic Acids Res 2023; 51:2485-2495. [PMID: 36807980 PMCID: PMC10018336 DOI: 10.1093/nar/gkad101] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 02/22/2023] Open
Abstract
The cyclic oligoadenylates (cOAs) act as second messengers of the type III CRISPR immunity system through activating the auxiliary nucleases for indiscriminate RNA degradation. The cOA-degrading nucleases (ring nucleases) provide an 'off-switch' regulation of the signaling, thereby preventing cell dormancy or cell death. Here, we describe the crystal structures of the founding member of CRISPR-associated ring nuclease 1 (Crn1) Sso2081 from Saccharolobus solfataricus, alone, bound to phosphate ions or cA4 in both pre-cleavage and cleavage intermediate states. These structures together with biochemical characterizations establish the molecular basis of cA4 recognition and catalysis by Sso2081. The conformational changes in the C-terminal helical insert upon the binding of phosphate ions or cA4 reveal a gate-locking mechanism for ligand binding. The critical residues and motifs identified in this study provide a new insight to distinguish between cOA-degrading and -nondegrading CARF domain-containing proteins.
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Affiliation(s)
- Liyang Du
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Danping Zhang
- College of Chemistry, Fuzhou University, Fuzhou 350108, China
| | - Zhipu Luo
- Correspondence may also be addressed to Zhipu Luo.
| | - Zhonghui Lin
- To whom correspondence should be addressed. Tel: +86 0591 22867273;
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22
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Cannone G, Kompaniiets D, Graham S, White MF, Spagnolo L. Structure of the Saccharolobus solfataricus type III-D CRISPR effector. Curr Res Struct Biol 2023; 5:100098. [PMID: 36843655 PMCID: PMC9945777 DOI: 10.1016/j.crstbi.2023.100098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/26/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023] Open
Abstract
CRISPR-Cas is a prokaryotic adaptive immune system, classified into six different types, each characterised by a signature protein. Type III systems, classified based on the presence of a Cas10 subunit, are rather diverse multi-subunit assemblies with a range of enzymatic activities and downstream ancillary effectors. The broad array of current biotechnological CRISPR applications is mainly based on proteins classified as Type II, however recent developments established the feasibility and efficacy of multi-protein Type III CRISPR-Cas effector complexes as RNA-targeting tools in eukaryotes. The crenarchaeon Saccharolobus solfataricus has two type III system subtypes (III-B and III-D). Here, we report the cryo-EM structure of the Csm Type III-D complex from S. solfataricus (SsoCsm), which uses CRISPR RNA to bind target RNA molecules, activating the Cas10 subunit for antiviral defence. The structure reveals the complex organisation, subunit/subunit connectivity and protein/guide RNA interactions of the SsoCsm complex, one of the largest CRISPR effectors known.
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Affiliation(s)
- Giuseppe Cannone
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, United Kingdom
| | - Dmytro Kompaniiets
- School of Molecular Biosciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Shirley Graham
- School of Biology, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Malcolm F. White
- School of Biology, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, UK
| | - Laura Spagnolo
- School of Molecular Biosciences, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
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23
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Yu Z, Xu J, She Q. Harnessing the LdCsm RNA Detection Platform for Efficient microRNA Detection. Int J Mol Sci 2023; 24:ijms24032857. [PMID: 36769177 PMCID: PMC9918065 DOI: 10.3390/ijms24032857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/24/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023] Open
Abstract
In cancer diagnosis, diverse microRNAs (miRNAs) are used as biomarkers for carcinogenesis of distinctive human cancers. Thus, the detection of these miRNAs and their quantification are very important in prevention of cancer diseases in human beings. However, efficient RNA detection often requires RT-PCR, which is very complex for miRNAs. Recently, the development of CRISPR-based nucleic acid detection tools has brought new promises to efficient miRNA detection. Three CRISPR systems can be explored for miRNA detection, including type III, V, and VI, among which type III (CRISPR-Cas10) systems have a unique property as they recognize RNA directly and cleave DNA collaterally. In particular, a unique type III-A Csm system encoded by Lactobacillus delbrueckii subsp. bulgaricus (LdCsm) exhibits robust target RNA-activated DNase activity, which makes it a promising candidate for developing efficient miRNA diagnostic tools. Herein, LdCsm was tested for RNA detection using fluorescence-quenched DNA reporters. We found that the system is capable of specific detection of miR-155, a microRNA implicated in the carcinogenesis of human breast cancer. The RNA detection system was then improved by various approaches including assay conditions and modification of the 5'-repeat tag of LdCsm crRNAs. Due to its robustness, the resulting LdCsm detection platform has the potential to be further developed as a better point-of-care miRNA diagnostics relative to other CRISPR-based RNA detection tools.
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Affiliation(s)
| | | | - Qunxin She
- Correspondence: ; Tel.: +86-532-58631522
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24
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Rouillon C, Schneberger N, Chi H, Blumenstock K, Da Vela S, Ackermann K, Moecking J, Peter MF, Boenigk W, Seifert R, Bode BE, Schmid-Burgk JL, Svergun D, Geyer M, White MF, Hagelueken G. Antiviral signalling by a cyclic nucleotide activated CRISPR protease. Nature 2023; 614:168-174. [PMID: 36423657 DOI: 10.1038/s41586-022-05571-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 11/17/2022] [Indexed: 11/27/2022]
Abstract
CRISPR defence systems such as the well-known DNA-targeting Cas9 and the RNA-targeting type III systems are widespread in prokaryotes1,2. The latter orchestrates a complex antiviral response that is initiated through the synthesis of cyclic oligoadenylates after recognition of foreign RNA3-5. Among the large set of proteins that are linked to type III systems and predicted to bind cyclic oligoadenylates6,7, a CRISPR-associated Lon protease (CalpL) stood out to us. CalpL contains a sensor domain of the SAVED family7 fused to a Lon protease effector domain. However, the mode of action of this effector is unknown. Here we report the structure and function of CalpL and show that this soluble protein forms a stable tripartite complex with two other proteins, CalpT and CalpS, that are encoded on the same operon. After activation by cyclic tetra-adenylate (cA4), CalpL oligomerizes and specifically cleaves the MazF homologue CalpT, which releases the extracytoplasmic function σ factor CalpS from the complex. Our data provide a direct connection between CRISPR-based detection of foreign nucleic acids and transcriptional regulation. Furthermore, the presence of a SAVED domain that binds cyclic tetra-adenylate in a CRISPR effector reveals a link to the cyclic-oligonucleotide-based antiphage signalling system.
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Affiliation(s)
- Christophe Rouillon
- Institute of Structural Biology, University of Bonn, Bonn, Germany.
- Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany.
| | | | - Haotian Chi
- School of Biology, University of St Andrews, St Andrews, UK
| | - Katja Blumenstock
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, Bonn, Germany
| | - Stefano Da Vela
- European Molecular Biology Laboratory (EMBL), Hamburg Site, Hamburg, Germany
| | - Katrin Ackermann
- EaStCHEM School of Chemistry, Biomedical Sciences Research Complex, and Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews, UK
| | - Jonas Moecking
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Martin F Peter
- Institute of Structural Biology, University of Bonn, Bonn, Germany
| | - Wolfgang Boenigk
- Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Reinhard Seifert
- Max Planck Institute for Neurobiology of Behavior-caesar, Bonn, Germany
| | - Bela E Bode
- EaStCHEM School of Chemistry, Biomedical Sciences Research Complex, and Centre of Magnetic Resonance, University of St Andrews, North Haugh, St Andrews, UK
| | - Jonathan L Schmid-Burgk
- Institute of Clinical Chemistry and Clinical Pharmacology, University of Bonn and University Hospital Bonn, Bonn, Germany
| | - Dmitri Svergun
- European Molecular Biology Laboratory (EMBL), Hamburg Site, Hamburg, Germany
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, Bonn, Germany
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25
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Byer AS, Pei X, Patterson MG, Ando N. Small-angle X-ray scattering studies of enzymes. Curr Opin Chem Biol 2023; 72:102232. [PMID: 36462455 PMCID: PMC9992928 DOI: 10.1016/j.cbpa.2022.102232] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 10/14/2022] [Accepted: 10/22/2022] [Indexed: 12/02/2022]
Abstract
Enzyme function requires conformational changes to achieve substrate binding, domain rearrangements, and interactions with partner proteins, but these movements are difficult to observe. Small-angle X-ray scattering (SAXS) is a versatile structural technique that can probe such conformational changes under solution conditions that are physiologically relevant. Although it is generally considered a low-resolution structural technique, when used to study conformational changes as a function of time, ligand binding, or protein interactions, SAXS can provide rich insight into enzyme behavior, including subtle domain movements. In this perspective, we highlight recent uses of SAXS to probe structural enzyme changes upon ligand and partner-protein binding and discuss tools for signal deconvolution of complex protein solutions.
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Affiliation(s)
- Amanda S Byer
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Xiaokun Pei
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Michael G Patterson
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Nozomi Ando
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA.
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26
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Ecology and evolution of phages encoding anti-CRISPR proteins. J Mol Biol 2023; 435:167974. [PMID: 36690071 DOI: 10.1016/j.jmb.2023.167974] [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: 10/27/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/21/2023]
Abstract
CRISPR-Cas are prokaryotic defence systems that provide protection against invasion by mobile genetic elements (MGE), including bacteriophages. MGE can overcome CRISPR-Cas defences by encoding anti-CRISPR (Acr) proteins. These proteins are produced in the early stages of the infection and inhibit the CRISPR-Cas machinery to allow phage replication. While research on Acr has mainly focused on their discovery, structure and mode of action, and their applications in biotechnology, the impact of Acr on the ecology of MGE as well as on the coevolution with their bacterial hosts only begins to be unravelled. In this review, we summarise our current understanding on the distribution of anti-CRISPR genes in MGE, the ecology of phages encoding Acr, and their coevolution with bacterial defence mechanisms. We highlight the need to use more diverse and complex experimental models to better understand the impact of anti-CRISPR in MGE-host interactions.
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27
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Malla RR, Middela K. CRISPR-Based Approaches for Cancer Immunotherapy. Crit Rev Oncog 2023; 28:1-14. [PMID: 38050977 DOI: 10.1615/critrevoncog.2023048723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) technology is a powerful gene editing tool that has the potential to revolutionize cancer treatment. It allows for precise and efficient editing of specific genes that drive cancer growth and progression. CRISPR-based approaches gene knock-out, which deletes specific genes or sequences of DNA within a cancer cell, and gene knock-in, which inserts new sequences of DNA into a cancer cell to identify potential targets for cancer therapy. Further, genome-wide CRISPR-Cas9-based screens identify specific markers for diagnosis of cancers. Recently, immunotherapy has become a highly efficient strategy for the treatment of cancer. The use of CRISPR in cancer immunotherapy is focused on enhancing the function of T cells, making them more effective at attacking cancer cells and inactivating the immune evasion mechanisms of cancer cells. It has the potential to generate CAR-T cells, which are T cells that have been genetically engineered to target and attack cancer cells specifically. This review uncovers the latest developments in CRISPR-based gene editing strategies and delivery of their components in cancer cells. In addition, the applications of CRISPR in cancer immune therapy are discussed. Overall, this review helps to explore the potential of CRISPR-based strategies in cancer immune therapy in clinical settings.
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Affiliation(s)
- Rama Rao Malla
- Cancer Biology Laboratory, Department of Biochemistry and Bioinformatics, School of Science, Gandhi Institute of Technology and Management (GITAM) (Deemed to be University), Visakhapatnam-530045, Andhra Pradesh, India; Department of Biochemistry and Bioinformatics, School of Science, GITAM (Deemed to be University), Visakhapatnam-530045, Andhra Pradesh, India
| | - Keerthana Middela
- Department of Biochemistry and Bioinformatics, School of Science, GITAM (Deemed to be University), Visakhapatnam-530045, Andhra Pradesh, India
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28
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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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29
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Ma M, Garza AG, Lemon DJ, Caro EA, Ritchie L, Ryan C, Spearing VM, Murphy KA, Welch RD. Identifying the Gene Regulatory Network of the Starvation-Induced Transcriptional Activator Nla28. J Bacteriol 2022; 204:e0026522. [PMID: 36448789 PMCID: PMC9765219 DOI: 10.1128/jb.00265-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 10/24/2022] [Indexed: 12/03/2022] Open
Abstract
Myxococcus xanthus copes with starvation by producing fruiting bodies filled with dormant and stress-resistant spores. Here, we aimed to better define the gene regulatory network associated with Nla28, a transcriptional activator/enhancer binding protein (EBP) and a key regulator of the early starvation response. Previous work showed that Nla28 directly regulates EBP genes that are important for fruiting body development. However, the Nla28 regulatory network is likely to be much larger because hundreds of starvation-induced genes are downregulated in a nla28 mutant strain. To identify candidates for direct Nla28-mediated transcription, we analyzed the downregulated genes using a bioinformatics approach. Nine potential Nla28 target promoters (29 genes) were discovered. The results of in vitro promoter binding assays, coupled with in vitro and in vivo mutational analyses, suggested that the nine promoters along with three previously identified EBP gene promoters were indeed in vivo targets of Nla28. These results also suggested that Nla28 used tandem, imperfect repeats of an 8-bp sequence for promoter binding. Interestingly, eight of the new Nla28 target promoters were predicted to be intragenic. Based on mutational analyses, the newly identified Nla28 target loci contained at least one gene that was important for starvation-induced development. Most of these loci contained genes predicted to be involved in metabolic or defense-related functions. Using the consensus Nla28 binding sequence, bioinformatics, and expression profiling, 58 additional promoters and 102 genes were tagged as potential Nla28 targets. Among these putative Nla28 targets, functions, such as regulatory, metabolic, and cell envelope biogenesis, were assigned to many genes. IMPORTANCE In bacteria, starvation leads to profound changes in behavior and physiology. Some of these changes have economic and health implications because the starvation response has been linked to the formation of biofilms, virulence, and antibiotic resistance. To better understand how starvation contributes to changes in bacterial physiology and resistance, we identified the putative starvation-induced gene regulatory network associated with Nla28, a transcriptional activator from the bacterium Myxoccocus xanthus. We determined the mechanism by which starvation-responsive genes were activated by Nla28 and showed that several of the genes were important for the formation of a highly resistant cell type.
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Affiliation(s)
- Muqing Ma
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Anthony G. Garza
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - David J. Lemon
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Eduardo A. Caro
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Linnea Ritchie
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Charles Ryan
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | | | | | - Roy D. Welch
- Department of Biology, Syracuse University, Syracuse, New York, USA
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30
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Patel DJ, Yu Y, Jia N. Bacterial origins of cyclic nucleotide-activated antiviral immune signaling. Mol Cell 2022; 82:4591-4610. [PMID: 36460008 PMCID: PMC9772257 DOI: 10.1016/j.molcel.2022.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 10/25/2022] [Accepted: 11/07/2022] [Indexed: 12/03/2022]
Abstract
Second-messenger-mediated signaling by cyclic oligonucleotides (cOs) composed of distinct base, ring size, and 3'-5'/2'-5' linkage combinations constitutes the initial trigger resulting in activation of signaling pathways that have an impact on immune-mediated antiviral defense against invading viruses and phages. Bacteria and archaea have evolved CRISPR, CBASS, Pycsar, and Thoeris surveillance complexes that involve cO-mediated activation of effectors resulting in antiviral defense through either targeted nuclease activity, effector oligomerization-mediated depletion of essential cellular metabolites or disruption of host cell membrane functions. Notably, antiviral defense capitalizes on an abortive infection mechanism, whereby infected cells die prior to completion of the phage replication cycle. In turn, phages have evolved small proteins that target and degrade/sequester cOs, thereby suppressing host immunity. This review presents a structure-based mechanistic perspective of recent advances in the field of cO-mediated antiviral defense, in particular highlighting the ancient evolutionary adaptation by metazoans of bacterial cell-autonomous innate immune mechanisms.
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Affiliation(s)
- Dinshaw J Patel
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
| | - You Yu
- Structural Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
| | - Ning Jia
- Department of Biochemistry, School of Medicine, Southern University of Science and Technology, Shenzhen 518055, China
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31
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Nemudraia A, Nemudryi A, Buyukyoruk M, Scherffius AM, Zahl T, Wiegand T, Pandey S, Nichols JE, Hall LN, McVey A, Lee HH, Wilkinson RA, Snyder LR, Jones JD, Koutmou KS, Santiago-Frangos A, Wiedenheft B. Sequence-specific capture and concentration of viral RNA by type III CRISPR system enhances diagnostic. Nat Commun 2022; 13:7762. [PMID: 36522348 PMCID: PMC9751510 DOI: 10.1038/s41467-022-35445-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
Type-III CRISPR-Cas systems have recently been adopted for sequence-specific detection of SARS-CoV-2. Here, we repurpose the type III-A CRISPR complex from Thermus thermophilus (TtCsm) for programmable capture and concentration of specific RNAs from complex mixtures. The target bound TtCsm complex generates two cyclic oligoadenylates (i.e., cA3 and cA4) that allosterically activate ancillary nucleases. We show that both Can1 and Can2 nucleases cleave single-stranded RNA, single-stranded DNA, and double-stranded DNA in the presence of cA4. We integrate the Can2 nuclease with type III-A RNA capture and concentration for direct detection of SARS-CoV-2 RNA in nasopharyngeal swabs with 15 fM sensitivity. Collectively, this work demonstrates how type-III CRISPR-based RNA capture and concentration simultaneously increases sensitivity, limits time to result, lowers cost of the assay, eliminates solvents used for RNA extraction, and reduces sample handling.
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Affiliation(s)
- Anna Nemudraia
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Artem Nemudryi
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Murat Buyukyoruk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Andrew M Scherffius
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Trevor Zahl
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Tanner Wiegand
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Shishir Pandey
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Joseph E Nichols
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Laina N Hall
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Aidan McVey
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Helen H Lee
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Royce A Wilkinson
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA
| | - Laura R Snyder
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Joshua D Jones
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Kristin S Koutmou
- Department of Chemistry, University of Michigan, Ann Arbor, MI, 48105, USA
| | - Andrew Santiago-Frangos
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA.
| | - Blake Wiedenheft
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, 59717, USA.
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32
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Liu X, Zhang L, Wang H, Xiu Y, Huang L, Gao Z, Li N, Li F, Xiong W, Gao T, Zhang Y, Yang M, Feng Y. Target RNA activates the protease activity of Craspase to confer antiviral defense. Mol Cell 2022; 82:4503-4518.e8. [PMID: 36306795 DOI: 10.1016/j.molcel.2022.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 09/19/2022] [Accepted: 10/05/2022] [Indexed: 11/30/2022]
Abstract
In the type III-E CRISPR-Cas system, a Cas effector (gRAMP) is associated with a TPR-CHAT to form Craspase (CRISPR-guided caspase). However, both the structural features of gRAMP and the immunity mechanism remain unknown for this system. Here, we report structures of gRAMP-crRNA and gRAMP:cRNA:target RNA as well as structures of Craspase and Craspase complexed with cognate target RNA (CTR) or non-cognate target RNA (NTR). Importantly, the 3' anti-tag region of NTR and CTR binds at two distinct channels in Craspase, and CTR with a non-complementary 3' anti-tag induces a marked conformational change of the TPR-CHAT, which allosterically activates its protease activity to cleave an ancillary protein Csx30. This cleavage then triggers an abortive infection as the antiviral strategy of the type III-E system. Together, our study provides crucial insights into both the catalytic mechanism of the gRAMP and the immunity mechanism of the type III-E system.
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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, Beijing 100029, 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, Beijing 100084, China.
| | - Hao Wang
- 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, Beijing 100029, 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, Beijing 100029, 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, Beijing 100029, China
| | - Zhengyu 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, Beijing 100029, China
| | - Ningning Li
- 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, Beijing 100029, China
| | - Feixue Li
- 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, Beijing 100029, China
| | - Weijia Xiong
- 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, Beijing 100029, China
| | - Teng Gao
- 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, Beijing 100084, 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, Beijing 100029, 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, Beijing 100084, 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, Beijing 100029, China.
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33
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Type III CRISPR-Cas provides resistance against nucleus-forming jumbo phages via abortive infection. Mol Cell 2022; 82:4471-4486.e9. [PMID: 36395770 DOI: 10.1016/j.molcel.2022.10.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 09/13/2022] [Accepted: 10/25/2022] [Indexed: 11/17/2022]
Abstract
Bacteria have diverse defenses against phages. In response, jumbo phages evade multiple DNA-targeting defenses by protecting their DNA inside a nucleus-like structure. We previously demonstrated that RNA-targeting type III CRISPR-Cas systems provide jumbo phage immunity by recognizing viral mRNA exported from the nucleus for translation. Here, we demonstrate that recognition of phage mRNA by the type III system activates a cyclic triadenylate-dependent accessory nuclease, NucC. Although unable to access phage DNA in the nucleus, NucC degrades the bacterial chromosome, triggers cell death, and disrupts phage replication and maturation. Hence, type-III-mediated jumbo phage immunity occurs via abortive infection, with suppression of the viral epidemic protecting the population. We further show that type III systems targeting jumbo phages have diverse accessory nucleases, including RNases that provide immunity. Our study demonstrates how type III CRISPR-Cas systems overcome the inaccessibility of jumbo phage DNA to provide robust immunity.
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34
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Ding J, Schuergers N, Baehre H, Wilde A. Enzymatic properties of CARF-domain proteins in Synechocystis sp. PCC 6803. Front Microbiol 2022; 13:1046388. [DOI: 10.3389/fmicb.2022.1046388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/18/2022] [Indexed: 11/09/2022] Open
Abstract
Prokaryotic CRISPR-Cas (clustered regularly interspaced short palindromic repeats and CRISPR-associated genes) systems provide immunity against invading genetic elements such as bacteriophages and plasmids. In type III CRISPR systems, the recognition of target RNA leads to the synthesis of cyclic oligoadenylate (cOA) second messengers that activate ancillary effector proteins via their CRISPR-associated Rossmann fold (CARF) domains. Commonly, these are ribonucleases (RNases) that unspecifically degrade both invader and host RNA. To mitigate adverse effects on cell growth, ring nucleases can degrade extant cOAs to switch off ancillary nucleases. Here we show that the model organism Synechocystis sp. PCC 6803 harbors functional CARF-domain effector and ring nuclease proteins. We purified and characterized the two ancillary CARF-domain proteins from the III-D type CRISPR system of this cyanobacterium. The Csx1 homolog, SyCsx1, is a cyclic tetraadenylate(cA4)-dependent RNase with a strict specificity for cytosine nucleotides. The second CARF-domain protein with similarity to Csm6 effectors, SyCsm6, did not show RNase activity in vitro but was able to break down cOAs and attenuate SyCsx1 RNase activity. Our data suggest that the CRISPR systems in Synechocystis confer a multilayered cA4-mediated defense mechanism.
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35
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Steens JA, Salazar CRP, Staals RH. The diverse arsenal of type III CRISPR-Cas-associated CARF and SAVED effectors. Biochem Soc Trans 2022; 50:1353-1364. [PMID: 36282000 PMCID: PMC9704534 DOI: 10.1042/bst20220289] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/28/2022] [Accepted: 10/10/2022] [Indexed: 09/14/2023]
Abstract
Type III CRISPR-Cas systems make use of a multi-subunit effector complex to target foreign (m)RNA transcripts complementary to the guide/CRISPR RNA (crRNA). Base-pairing of the target RNA with specialized regions in the crRNA not only triggers target RNA cleavage, but also activates the characteristic Cas10 subunit and sets in motion a variety of catalytic activities that starts with the production of cyclic oligoadenylate (cOA) second messenger molecules. These messenger molecules can activate an extensive arsenal of ancillary effector proteins carrying the appropriate sensory domain. Notably, the CARF and SAVED effector proteins have been responsible for renewed interest in type III CRISPR-Cas due to the extraordinary diversity of defenses against invading genetic elements. Whereas only a handful of CARF and SAVED proteins have been studied so far, many of them seem to provoke abortive infection, aimed to kill the host and provide population-wide immunity. A defining feature of these effector proteins is the variety of in silico-predicted catalytic domains they are fused to. In this mini-review, we discuss all currently characterized type III-associated CARF and SAVED effector proteins, highlight a few examples of predicted CARF and SAVED proteins with interesting predicted catalytic activities, and speculate how they could contribute to type III immunity.
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Affiliation(s)
- Jurre A. Steens
- 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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36
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Molina R, Garcia-Martin R, López-Méndez B, Jensen ALG, Ciges-Tomas JR, Marchena-Hurtado J, Stella S, Montoya G. Molecular basis of cyclic tetra-oligoadenylate processing by small standalone CRISPR-Cas ring nucleases. Nucleic Acids Res 2022; 50:11199-11213. [PMID: 36271789 PMCID: PMC9638899 DOI: 10.1093/nar/gkac923] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 10/03/2022] [Accepted: 10/07/2022] [Indexed: 11/24/2022] Open
Abstract
Standalone ring nucleases are CRISPR ancillary proteins, which downregulate the immune response of Type III CRISPR-Cas systems by cleaving cyclic oligoadenylates (cA) second messengers. Two genes with this function have been found within the Sulfolobus islandicus (Sis) genome. They code for a long polypeptide composed by a CARF domain fused to an HTH domain and a short polypeptide constituted by a CARF domain with a 40 residue C-terminal insertion. Here, we determine the structure of the apo and substrate bound states of the Sis0455 enzyme, revealing an insertion at the C-terminal region of the CARF domain, which plays a key role closing the catalytic site upon substrate binding. Our analysis reveals the key residues of Sis0455 during cleavage and the coupling of the active site closing with their positioning to proceed with cA4 phosphodiester hydrolysis. A time course comparison of cA4 cleavage between the short, Sis0455, and long ring nucleases, Sis0811, shows the slower cleavage kinetics of the former, suggesting that the combination of these two types of enzymes with the same function in a genome could be an evolutionary strategy to regulate the levels of the second messenger in different infection scenarios.
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Affiliation(s)
- Rafael Molina
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark
| | - Ricardo Garcia-Martin
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark
| | - Blanca López-Méndez
- The Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Anne Louise Grøn Jensen
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark
| | - J Rafael Ciges-Tomas
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark
| | - Javier Marchena-Hurtado
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark
| | - Stefano Stella
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark
| | - Guillermo Montoya
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, 2200 Copenhagen, Denmark.,The Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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37
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Abstract
Advances in our understanding of prokaryotic antiphage defense mechanisms in the past few years have revealed a multitude of new cyclic nucleotide signaling molecules that play a crucial role in switching infected cells into an antiviral state. Defense pathways including type III CRISPR (clustered regularly interspaced palindromic repeats), CBASS (cyclic nucleotide-based antiphage signaling system), PYCSAR (pyrimidine cyclase system for antiphage resistance), and Thoeris all use cyclic nucleotides as second messengers to activate a diverse range of effector proteins. These effectors typically degrade or disrupt key cellular components such as nucleic acids, membranes, or metabolites, slowing down viral replication kinetics at great cost to the infected cell. Mechanisms to manipulate the levels of cyclic nucleotides are employed by cells to regulate defense pathways and by viruses to subvert them. Here we review the discovery and mechanism of the key pathways, signaling molecules and effectors, parallels and differences between the systems, open questions, and prospects for future research in this area.
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Affiliation(s)
- Januka S Athukoralage
- Department of Microbiology and Immunology, University of California, San Francisco, California, USA
| | - Malcolm F White
- School of Biology, University of St Andrews, St Andrews, United Kingdom;
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38
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Ma Y, Li X, Zhao R, Wu E, Du Q, Guo J, Wang L, Zhang F. Creating de novo peptide-based bioactivities: from assembly to origami. RSC Adv 2022; 12:25955-25961. [PMID: 36199601 PMCID: PMC9465703 DOI: 10.1039/d2ra03135c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/24/2022] [Indexed: 11/21/2022] Open
Abstract
DNA origami has created complex structures of various spatial dimensions. However, their versatility in terms of function is limited due to the lower number of the intrinsic building blocks, i.e. nucleotides, compared with the number of amino acids. Therefore, protein origami has been proposed and demonstrated to precisely fabricate artificial functional nanostructures. Despite their hierarchical folded structures, chain-like peptides and DNA share obvious similarities in both structures and properties, especially in terms of chain hybridization; therefore, replacing DNA with peptides to create bioactivities not only has high theoretical feasibility but also provides a new bottom-up synthetic strategy. However, designing functionalities with tens to hundreds of peptide chains using the similar principle of DNA origami has not been reported, although the origami strategy holds great potential to generate more complex bioactivities. In this perspective review, we have reviewed the recent progress in and highlighted the advantages of peptide assembly and origami on the orientation of artificially created bioactivities. With the great potential of peptide origami, we appeal to develop user-friendly softwares in combination with artificial intelligence.
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Affiliation(s)
- Yuxing Ma
- Wenzhou Institute, University of Chinese Academy of Sciences Wenzhou 325001 China
- Oujiang Laboratory Wenzhou Zhejiang 325000 P. R. China
- Inner Mongolia Key Laboratory of Tick-Borne Zoonotic Infectious Disease, Department of Medicine, Hetao College Bayannur 015000 China
| | - Xiaofang Li
- Wenzhou Institute, University of Chinese Academy of Sciences Wenzhou 325001 China
- Oujiang Laboratory Wenzhou Zhejiang 325000 P. R. China
- Key Laboratory of Optical Technology and Instrument for Medicine, Ministry of Education, University of Shanghai for Science and Technology Shanghai 200093 P. R. China
| | - Ruoyang Zhao
- Wenzhou Institute, University of Chinese Academy of Sciences Wenzhou 325001 China
- Oujiang Laboratory Wenzhou Zhejiang 325000 P. R. China
| | - Enqi Wu
- Inner Mongolia Key Laboratory of Tick-Borne Zoonotic Infectious Disease, Department of Medicine, Hetao College Bayannur 015000 China
| | - Qiqige Du
- Wenzhou Institute, University of Chinese Academy of Sciences Wenzhou 325001 China
- Oujiang Laboratory Wenzhou Zhejiang 325000 P. R. China
| | - Jun Guo
- Key Laboratory of Optical Technology and Instrument for Medicine, Ministry of Education, University of Shanghai for Science and Technology Shanghai 200093 P. R. China
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Oral Disease, Stomatology Hospital, School of Biomedical Engineering, Guangzhou Medical University Guangzhou 511436 China
| | - Liping Wang
- Wenzhou Institute, University of Chinese Academy of Sciences Wenzhou 325001 China
- Oujiang Laboratory Wenzhou Zhejiang 325000 P. R. China
| | - Feng Zhang
- Wenzhou Institute, University of Chinese Academy of Sciences Wenzhou 325001 China
- Oujiang Laboratory Wenzhou Zhejiang 325000 P. R. China
- Key Laboratory of Optical Technology and Instrument for Medicine, Ministry of Education, University of Shanghai for Science and Technology Shanghai 200093 P. R. China
- State Key Laboratory of Respiratory Disease, Guangzhou Institute of Oral Disease, Stomatology Hospital, School of Biomedical Engineering, Guangzhou Medical University Guangzhou 511436 China
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39
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Santiago-Frangos A, Nemudryi A, Nemudraia A, Wiegand T, Nichols JE, Krishna P, Scherffius AM, Zahl TR, Wilkinson RA, Wiedenheft B. CRISPR-Cas, Argonaute proteins and the emerging landscape of amplification-free diagnostics. Methods 2022; 205:1-10. [PMID: 35690249 PMCID: PMC9181078 DOI: 10.1016/j.ymeth.2022.06.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 05/06/2022] [Accepted: 06/04/2022] [Indexed: 01/04/2023] Open
Abstract
Polymerase Chain Reaction (PCR) is the reigning gold standard for molecular diagnostics. However, the SARS-CoV-2 pandemic reveals an urgent need for new diagnostics that provide users with immediate results without complex procedures or sophisticated equipment. These new demands have stimulated a tsunami of innovations that improve turnaround times without compromising the specificity and sensitivity that has established PCR as the paragon of diagnostics. Here we briefly introduce the origins of PCR and isothermal amplification, before turning to the emergence of CRISPR-Cas and Argonaute proteins, which are being coupled to fluorimeters, spectrometers, microfluidic devices, field-effect transistors, and amperometric biosensors, for a new generation of nucleic acid-based diagnostics.
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Affiliation(s)
| | - Artem Nemudryi
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Anna Nemudraia
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Tanner Wiegand
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Joseph E Nichols
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Pushya Krishna
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Andrew M Scherffius
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Trevor R Zahl
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Royce A Wilkinson
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Blake Wiedenheft
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA.
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40
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Marino ND, Pinilla-Redondo R, Bondy-Denomy J. CRISPR-Cas12a targeting of ssDNA plays no detectable role in immunity. Nucleic Acids Res 2022; 50:6414-6422. [PMID: 35670674 PMCID: PMC9226536 DOI: 10.1093/nar/gkac462] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 05/12/2022] [Accepted: 05/23/2022] [Indexed: 12/17/2022] Open
Abstract
CRISPR-Cas12a (Cpf1) is a bacterial RNA-guided nuclease that cuts double-stranded DNA (dsDNA) at sites specified by a CRISPR RNA (crRNA) guide. Additional activities have been ascribed to this enzyme in vitro: site-specific (cis) single-stranded DNA (ssDNA) cleavage and indiscriminate (trans) degradation of ssDNA, RNA, and dsDNA after activation by a complementary target. The ability of Cas12a to cleave nucleic acids indiscriminately has been harnessed for many applications, including diagnostics, but it remains unknown if it contributes to bacterial immunity. Here, we provide evidence that cleavage of ssDNA in cis or in trans by Cas12a is insufficient to impact immunity. Using LbCas12a expressed in either Pseudomonas aeruginosa or Escherichia coli, we observed that cleavage of dsDNA targets did not elicit cell death or dormancy, suggesting insignificant levels of collateral damage against host RNA or DNA. Canonical immunity against invasive dsDNA also had no impact on the replicative fitness of co-infecting dsDNA phage, ssDNA phage or plasmid in trans. Lastly, crRNAs complementary to invasive ssDNA did not provide protection, suggesting that ssDNA cleavage does not occur in vivo or is insignificant. Overall, these results suggest that CRISPR-Cas12a immunity predominantly occurs via canonical targeting of dsDNA, and that the other activities do not significantly impact infection outcomes.
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Affiliation(s)
- Nicole D Marino
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Rafael Pinilla-Redondo
- Section of Microbiology, University of Copenhagen, Universitetsparken 15, 2100 Copenhagen, Denmark
| | - Joseph Bondy-Denomy
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
- Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA 94158, USA
- Innovative Genomics Institute, Berkeley, CA 94720, USA
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41
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Smith EM, Ferrell S, Tokars VL, Mondragón A. Structures of an active type III-A CRISPR effector complex. Structure 2022; 30:1109-1128.e6. [PMID: 35714601 PMCID: PMC9357104 DOI: 10.1016/j.str.2022.05.013] [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: 04/30/2022] [Revised: 05/09/2022] [Accepted: 05/17/2022] [Indexed: 10/18/2022]
Abstract
Clustered regularly interspaced short palindromic repeats (CRISPR) and their CRISPR-associated proteins (Cas) provide many prokaryotes with an adaptive immune system against invading genetic material. Type III CRISPR systems are unique in that they can degrade both RNA and DNA. In response to invading nucleic acids, they produce cyclic oligoadenylates that act as secondary messengers, activating cellular nucleases that aid in the immune response. Here, we present seven single-particle cryo-EM structures of the type III-A Staphylococcus epidermidis CRISPR effector complex. The structures reveal the intact S. epidermidis effector complex in an apo, ATP-bound, cognate target RNA-bound, and non-cognate target RNA-bound states and illustrate how the effector complex binds and presents crRNA. The complexes bound to target RNA capture the type III-A effector complex in a post-RNA cleavage state. The ATP-bound structures give details about how ATP binds to Cas10 to facilitate cyclic oligoadenylate production.
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Affiliation(s)
- Eric M Smith
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Sé Ferrell
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA
| | - Valerie L Tokars
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Alfonso Mondragón
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208, USA.
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42
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Nemudraia A, Nemudryi A, Buyukyoruk M, Scherffius AM, Zahl T, Wiegand T, Pandey S, Nichols JE, Hall L, McVey A, Lee HH, Wilkinson RA, Snyder LR, Jones JD, Koutmou KS, Santiago-Frangos A, Wiedenheft B. Sequence-specific capture and concentration of viral RNA by type III CRISPR system enhances diagnostic. RESEARCH SQUARE 2022:rs.3.rs-1466718. [PMID: 35475170 PMCID: PMC9040678 DOI: 10.21203/rs.3.rs-1466718/v1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Type-III CRISPR-Cas systems have recently been adopted for sequence-specific detection of SARS-CoV-2. Here, we make two major advances that simultaneously limit sample handling and significantly enhance the sensitivity of SARS-CoV-2 RNA detection directly from patient samples. First, we repurpose the type III-A CRISPR complex from Thermus thermophilus (TtCsm) for programmable capture and concentration of specific RNAs from complex mixtures. The target bound TtCsm complex primarily generates two cyclic oligoadenylates (i.e., cA3 and cA4) that allosterically activate ancillary nucleases. To improve sensitivity of the diagnostic, we identify and test several ancillary nucleases (i.e., Can1, Can2, and NucC). We show that Can1 and Can2 are activated by both cA3 and cA4, and that different activators trigger changes in the substrate specificity of these nucleases. Finally, we integrate the type III-A CRISPR RNA-guided capture technique with the Can2 nuclease for 90 fM (5x104 copies/ul) detection of SARS-CoV-2 RNA directly from nasopharyngeal swab samples.
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Affiliation(s)
- Anna Nemudraia
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
- These authors contributed equally
| | - Artem Nemudryi
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
- These authors contributed equally
| | - Murat Buyukyoruk
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
- These authors contributed equally
| | - Andrew M. Scherffius
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
- These authors contributed equally
| | - Trevor Zahl
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Tanner Wiegand
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Shishir Pandey
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Joseph E. Nichols
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Laina Hall
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Aidan McVey
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Helen H Lee
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Royce A. Wilkinson
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Laura R. Snyder
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48105, USA
| | - Joshua D. Jones
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48105, USA
| | - Kristin S. Koutmou
- Department of Chemistry, University of Michigan, Ann Arbor, MI 48105, USA
| | - Andrew Santiago-Frangos
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
| | - Blake Wiedenheft
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT 59717, USA
- Lead contact
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43
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Duncan-Lowey B, Kranzusch PJ. CBASS phage defense and evolution of antiviral nucleotide signaling. Curr Opin Immunol 2022; 74:156-163. [PMID: 35123147 DOI: 10.1016/j.coi.2022.01.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 01/14/2022] [Accepted: 01/15/2022] [Indexed: 12/16/2022]
Abstract
Cyclic oligonucleotide-based antiphage signaling system (CBASS) immunity is a widespread form of antiphage defense in bacteria and archaea. Each CBASS operon encodes a cGAS/DncV-like Nucleotidyltransferase (CD-NTase) enzyme that synthesizes a nucleotide second messenger in response to viral infection. An associated Cap effector protein then binds the nucleotide signal and executes cell death to destroy the host cell and block phage propagation. Here we build upon recent advances to establish rules controlling each step of CBASS activation and antiphage defense. Comparative analysis of CBASS, CRISPR, Pycsar, and cGAS-STING immunity provides insight into the evolution of phage defense and animal innate immunity and highlights new questions emerging in the role of nucleotide second messenger signaling in host-virus interactions.
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Affiliation(s)
- Brianna Duncan-Lowey
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - Philip J Kranzusch
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Boston, MA 02115, USA; Parker Institute for Cancer Immunotherapy at Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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44
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Xia P, Dutta A, Gupta K, Batish M, Parashar V. Structural basis of cyclic oligoadenylate binding to the transcription factor Csa3 outlines cross talk between type III and type I CRISPR systems. J Biol Chem 2022; 298:101591. [PMID: 35038453 PMCID: PMC8844856 DOI: 10.1016/j.jbc.2022.101591] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 01/28/2023] Open
Abstract
RNA interference by type III CRISPR systems results in the synthesis of cyclic oligoadenylate (cOA) second messengers, which are known to bind and regulate various CARF domain-containing nuclease receptors. The CARF domain-containing Csa3 family of transcriptional factors associated with the DNA-targeting type I CRISPR systems regulate expression of various CRISPR and DNA repair genes in many prokaryotes. In this study, we extend the known receptor repertoire of cOA messengers to include transcriptional factors by demonstrating specific binding of cyclic tetra-adenylate (cA4) to Saccharolobus solfataricus Csa3 (Csa3Sso). Our 2.0-Å resolution X-ray crystal structure of cA4-bound full-length Csa3Sso reveals the binding of its CARF domain to an elongated conformation of cA4. Using cA4 binding affinity analyses of Csa3Sso mutants targeting the observed Csa3Sso•cA4 structural interface, we identified a Csa3-specific cA4 binding motif distinct from a more widely conserved cOA-binding CARF motif. Using a rational surface engineering approach, we increased the cA4 binding affinity of Csa3Sso up to ∼145-fold over the wildtype, which has potential applications for future second messenger-driven CRISPR gene expression and editing systems. Our in-solution Csa3Sso structural analysis identified cA4-induced allosteric and asymmetric conformational rearrangement of its C-terminal winged helix-turn-helix effector domains, which could potentially be incompatible to DNA binding. However, specific in vitro binding of the purified Csa3Sso to its putative promoter (PCas4a) was found to be cA4 independent, suggesting a complex mode of Csa3Sso regulation. Overall, our results support cA4-and Csa3-mediated cross talk between type III and type I CRISPR systems.
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Affiliation(s)
- Pengjun Xia
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA
| | - Anirudha Dutta
- Department of Medical and Molecular Sciences, University of Delaware, Newark, Delaware, USA
| | - Kushol Gupta
- The Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mona Batish
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA; Department of Medical and Molecular Sciences, University of Delaware, Newark, Delaware, USA
| | - Vijay Parashar
- Department of Biological Sciences, University of Delaware, Newark, Delaware, USA; Department of Medical and Molecular Sciences, University of Delaware, Newark, Delaware, USA.
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45
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Alternative functions of CRISPR-Cas systems in the evolutionary arms race. Nat Rev Microbiol 2022; 20:351-364. [PMID: 34992260 DOI: 10.1038/s41579-021-00663-z] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2021] [Indexed: 12/14/2022]
Abstract
CRISPR-Cas systems of bacteria and archaea comprise chromosomal loci with typical repetitive clusters and associated genes encoding a range of Cas proteins. Adaptation of CRISPR arrays occurs when virus-derived and plasmid-derived sequences are integrated as new CRISPR spacers. Cas proteins use CRISPR-derived RNA guides to specifically recognize and cleave nucleic acids of invading mobile genetic elements. Apart from this role as an adaptive immune system, some CRISPR-associated nucleases are hijacked by mobile genetic elements: viruses use them to attack their prokaryotic hosts, and transposons have adopted CRISPR systems for guided transposition. In addition, some CRISPR-Cas systems control the expression of genes involved in bacterial physiology and virulence. Moreover, pathogenic bacteria may use their Cas nuclease activity indirectly to evade the human immune system or directly to invade the nucleus and damage the chromosomal DNA of infected human cells. Thus, the evolutionary arms race has led to the expansion of exciting variations in CRISPR mechanisms and functionalities. In this Review, we explore the latest insights into the diverse functions of CRISPR-Cas systems beyond adaptive immunity and discuss the implications for the development of CRISPR-based applications.
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46
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Wimmer E, Zink IA, Schleper C. Reprogramming CRISPR-Mediated RNA Interference for Silencing of Essential Genes in Sulfolobales. Methods Mol Biol 2022; 2522:177-201. [PMID: 36125750 DOI: 10.1007/978-1-0716-2445-6_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The manipulation of gene expression levels in vivo is often key to elucidating gene function and regulatory network interactions, especially when it comes to the investigation of essential genes that cannot be deleted from the model organism's genome. Several techniques have been developed for prokaryotes that allow to interfere with transcription initiation of specific genes by blocking or modifying promoter regions. However, a tool functionally similar to RNAi used in eukaryotes to efficiently degrade mRNA posttranscriptionally did not exist until recently. Type III CRISPR-Cas systems use small RNAs (crRNAs) that guide effector complexes (encoded by cas genes) which act as site-specific RNA endonuclease and can thus be harnessed for targeted posttranscriptional gene silencing. Guide RNAs complementary to the desired target mRNA that, in addition, exhibit complementarity to repeat sequences found in the CRISPR arrays, effectively suppress unspecific DNA and RNA activities of the CRISPR-Cas complexes. Here we describe the use of endogenous type III CRISPR-Cas systems in two model organisms of Crenarchaeota, Saccharolobus solfataricus and Sulfolobus acidocaldarius.
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Affiliation(s)
- Erika Wimmer
- Department of Functional and Evolutionary Ecology, Archaea Biology and Ecogenomics Unit, University of Vienna, Vienna, Austria
| | - Isabelle Anna Zink
- Laboratory of Microbiology, Wageningen University and Research, Wageningen, The Netherlands
| | - Christa Schleper
- Department of Functional and Evolutionary Ecology, Archaea Biology and Ecogenomics Unit, University of Vienna, Vienna, Austria.
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47
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Abstract
The principal biological function of bacterial and archaeal CRISPR systems is RNA-guided adaptive immunity against viruses and other mobile genetic elements (MGEs). These systems show remarkable evolutionary plasticity and functional versatility at multiple levels, including both the defense mechanisms that lead to direct, specific elimination of the target DNA or RNA and those that cause programmed cell death (PCD) or induction of dormancy. This flexibility is also evident in the recruitment of CRISPR systems for nondefense functions. Defective CRISPR systems or individual CRISPR components have been recruited by transposons for RNA-guided transposition, by plasmids for interplasmid competition, and by viruses for antidefense and interviral conflicts. Additionally, multiple highly derived CRISPR variants of yet unknown functions have been discovered. A major route of innovation in CRISPR evolution is the repurposing of diverged repeat variants encoded outside CRISPR arrays for various structural and regulatory functions. The evolutionary plasticity and functional versatility of CRISPR systems are striking manifestations of the ubiquitous interplay between defense and “normal” cellular functions. The CRISPR systems show remarkable functional versatility beyond their principal function as an adaptive immune mechanism. This Essay discusses how derived CRISPR systems have been recruited by transposons on multiple occasions and mediate RNA-guided transposition; derived CRISPR RNAs are frequently recruited for regulatory functions.
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Affiliation(s)
- Eugene V. Koonin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
| | - Kira S. Makarova
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, United States of America
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48
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Chou-Zheng L, Hatoum-Aslan A. Critical roles for 'housekeeping' nucleases in type III CRISPR-Cas immunity. eLife 2022; 11:81897. [PMID: 36479971 PMCID: PMC9762709 DOI: 10.7554/elife.81897] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/07/2022] [Indexed: 12/13/2022] Open
Abstract
CRISPR-Cas systems are a family of adaptive immune systems that use small CRISPR RNAs (crRNAs) and CRISPR-associated (Cas) nucleases to protect prokaryotes from invading plasmids and viruses (i.e., phages). Type III systems launch a multilayered immune response that relies upon both Cas and non-Cas cellular nucleases, and although the functions of Cas components have been well described, the identities and roles of non-Cas participants remain poorly understood. Previously, we showed that the type III-A CRISPR-Cas system in Staphylococcus epidermidis employs two degradosome-associated nucleases, PNPase and RNase J2, to promote crRNA maturation and eliminate invading nucleic acids (Chou-Zheng and Hatoum-Aslan, 2019). Here, we identify RNase R as a third 'housekeeping' nuclease critical for immunity. We show that RNase R works in concert with PNPase to complete crRNA maturation and identify specific interactions with Csm5, a member of the type III effector complex, which facilitate nuclease recruitment/stimulation. Furthermore, we demonstrate that RNase R and PNPase are required to maintain robust anti-plasmid immunity, particularly when targeted transcripts are sparse. Altogether, our findings expand the known repertoire of accessory nucleases required for type III immunity and highlight the remarkable capacity of these systems to interface with diverse cellular pathways to ensure successful defense.
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Affiliation(s)
- Lucy Chou-Zheng
- Microbiology Department, University of Illinois Urbana-ChampaignUrbanaUnited States
| | - Asma Hatoum-Aslan
- Microbiology Department, University of Illinois Urbana-ChampaignUrbanaUnited States
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49
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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: 36] [Impact Index Per Article: 12.0] [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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Molina R, Jensen ALG, Marchena-Hurtado J, López-Méndez B, Stella S, Montoya G. Structural basis of cyclic oligoadenylate degradation by ancillary Type III CRISPR-Cas ring nucleases. Nucleic Acids Res 2021; 49:12577-12590. [PMID: 34850143 PMCID: PMC8643638 DOI: 10.1093/nar/gkab1130] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 10/22/2021] [Accepted: 10/26/2021] [Indexed: 12/26/2022] Open
Abstract
Type III CRISPR-Cas effector systems detect foreign RNA triggering DNA and RNA cleavage and synthesizing cyclic oligoadenylate molecules (cA) in their Cas10 subunit. cAs act as a second messenger activating auxiliary nucleases, leading to an indiscriminate RNA degradation that can end in cell dormancy or death. Standalone ring nucleases are CRISPR ancillary proteins which downregulate the strong immune response of Type III systems by degrading cA. These enzymes contain a CRISPR-associated Rossman-fold (CARF) domain, which binds and cleaves the cA molecule. Here, we present the structures of the standalone ring nuclease from Sulfolobus islandicus (Sis) 0811 in its apo and post-catalytic states. This enzyme is composed by a N-terminal CARF and a C-terminal wHTH domain. Sis0811 presents a phosphodiester hydrolysis metal-independent mechanism, which cleaves cA4 rings to generate linear adenylate species, thus reducing the levels of the second messenger and switching off the cell antiviral state. The structural and biochemical analysis revealed the coupling of a cork-screw conformational change with the positioning of key catalytic residues to proceed with cA4 phosphodiester hydrolysis in a non-concerted manner.
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Affiliation(s)
- Rafael Molina
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, Copenhagen, 2200, Denmark
| | - Anne Louise Grøn Jensen
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, Copenhagen, 2200, Denmark
| | - Javier Marchena-Hurtado
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, Copenhagen, 2200, Denmark
| | - Blanca López-Méndez
- The Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Stefano Stella
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, Copenhagen, 2200, Denmark
| | - Guillermo Montoya
- Structural Molecular Biology Group, Novo Nordisk Foundation Centre for Protein Research, Faculty of Health and Medical Sciences University of Copenhagen, Blegdamsvej 3-B, Copenhagen, 2200, Denmark.,The Novo Nordisk Foundation Center for Protein Research, Protein Structure & Function Programme, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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