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Andrzejewska-Romanowska A, Gumna J, Tykwińska E, Pachulska-Wieczorek K. Mapping the structural landscape of the yeast Ty3 retrotransposon RNA genome. Nucleic Acids Res 2024:gkae494. [PMID: 38864374 DOI: 10.1093/nar/gkae494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/30/2024] [Accepted: 05/29/2024] [Indexed: 06/13/2024] Open
Abstract
Long terminal repeat (LTR)-retrotransposons are significant contributors to the evolution and diversity of eukaryotic genomes. Their RNA genomes (gRNA) serve as a template for protein synthesis and reverse transcription to a DNA copy, which can integrate into the host genome. Here, we used the SHAPE-MaP strategy to explore Ty3 retrotransposon gRNA structure in yeast and under cell-free conditions. Our study reveals the structural dynamics of Ty3 gRNA and the well-folded core, formed independently of the cellular environment. Based on the detailed map of Ty3 gRNA structure, we characterized the structural context of cis-acting sequences involved in reverse transcription and frameshifting. We also identified a novel functional sequence as a potential initiator for Ty3 gRNA dimerization. Our data indicate that the dimer is maintained by direct interaction between short palindromic sequences at the 5' ends of the two Ty3 gRNAs, resembling the model characteristic for other retroelements like HIV-1 and Ty1. This work points out a range of cell-dependent and -independent Ty3 gRNA structural changes that provide a solid background for studies on RNA structure-function relationships important for retroelement biology.
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Affiliation(s)
- Angelika Andrzejewska-Romanowska
- Department of RNA Structure and Function, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Julita Gumna
- Department of RNA Structure and Function, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Ewa Tykwińska
- Department of RNA Structure and Function, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
| | - Katarzyna Pachulska-Wieczorek
- Department of RNA Structure and Function, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznan, Poland
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2
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Madhugiri R, Nguyen HV, Slanina H, Ziebuhr J. Alpha- and betacoronavirus cis-acting RNA elements. Curr Opin Microbiol 2024; 79:102483. [PMID: 38723345 DOI: 10.1016/j.mib.2024.102483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 06/11/2024]
Abstract
Coronaviruses have exceptionally large RNA genomes and employ multiprotein replication/transcription complexes to orchestrate specific steps of viral RNA genome replication and expression. Most of these processes involve viral cis-acting RNA elements that are engaged in vital RNA-RNA and/or RNA-protein interactions. Over the past years, a large number of studies provided interesting new insight into the structures and, to a lesser extent, functions of specific RNA elements for representative coronaviruses, and there is evidence to suggest that (a majority of) these RNA elements are conserved across genetically divergent coronavirus genera. It is becoming increasingly clear that at least some of these elements do not function in isolation but operate through complex and highly dynamic RNA-RNA interactions. This article reviews structural and functional aspects of cis-acting RNA elements conserved in alpha- and betacoronavirus 5'- and 3'-terminal genome regions, focusing on their critical roles in viral RNA synthesis and gene expression.
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Affiliation(s)
- Ramakanth Madhugiri
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - Hoang Viet Nguyen
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - Heiko Slanina
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - John Ziebuhr
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany.
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3
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Vögele J, Duchardt-Ferner E, Bains JK, Knezic B, Wacker A, Sich C, Weigand JE, Šponer J, Schwalbe H, Krepl M, Wöhnert J. Structure of an internal loop motif with three consecutive U•U mismatches from stem-loop 1 in the 3'-UTR of the SARS-CoV-2 genomic RNA. Nucleic Acids Res 2024:gkae349. [PMID: 38783391 DOI: 10.1093/nar/gkae349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 05/25/2024] Open
Abstract
The single-stranded RNA genome of SARS-CoV-2 is highly structured. Numerous helical stem-loop structures interrupted by mismatch motifs are present in the functionally important 5'- and 3'-UTRs. These mismatches modulate local helical geometries and feature unusual arrays of hydrogen bonding donor and acceptor groups. However, their conformational and dynamical properties cannot be directly inferred from chemical probing and are difficult to predict theoretically. A mismatch motif (SL1-motif) consisting of three consecutive U•U base pairs is located in stem-loop 1 of the 3'-UTR. We combined NMR-spectroscopy and MD-simulations to investigate its structure and dynamics. All three U•U base pairs feature two direct hydrogen bonds and are as stable as Watson-Crick A:U base pairs. Plasmodium falciparum 25S rRNA contains a triple U•U mismatch motif (Pf-motif) differing from SL1-motif only with respect to the orientation of the two closing base pairs. Interestingly, while the geometry of the outer two U•U mismatches was identical in both motifs the preferred orientation of the central U•U mismatch was different. MD simulations and potassium ion titrations revealed that the potassium ion-binding mode to the major groove is connected to the different preferred geometries of the central base pair in the two motifs.
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Affiliation(s)
- Jennifer Vögele
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Elke Duchardt-Ferner
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
| | - Jasleen Kaur Bains
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Bozana Knezic
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Anna Wacker
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Christian Sich
- Volkswagen AG, Brieffach 1617/0, 38436 Wolfsburg, Germany
| | - Julia E Weigand
- Institute of Pharmaceutical Chemistry, University of Marburg, Marbacher Weg 6, 35037 Marburg, Germany
| | - Jiří Šponer
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 00 Brno, Czech Republic
| | - Harald Schwalbe
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Institute of Organic Chemistry and Chemical Biology, Max-von-Laue-Str. 7, 60438 Frankfurt, Germany
| | - Miroslav Krepl
- Institute of Biophysics of the Czech Academy of Sciences, Kralovopolska 135, 612 00 Brno, Czech Republic
| | - Jens Wöhnert
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe-University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt, Germany
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4
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Kumar A, Kaushal R, Sharma H, Sharma K, Menon MB, P V. Mapping of long stretches of highly conserved sequences in over 6 million SARS-CoV-2 genomes. Brief Funct Genomics 2024; 23:256-264. [PMID: 37461194 DOI: 10.1093/bfgp/elad027] [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: 01/27/2023] [Revised: 06/15/2023] [Accepted: 06/26/2023] [Indexed: 05/18/2024] Open
Abstract
We identified 11 conserved stretches in over 6.3 million SARS-CoV-2 genomes including all the major variants of concerns. Each conserved stretch is ≥100 nucleotides in length with ≥99.9% conservation at each nucleotide position. Interestingly, six of the eight conserved stretches in ORF1ab overlapped significantly with well-folded experimentally verified RNA secondary structures. Furthermore, two of the conserved stretches were mapped to regions within the S2-subunit that undergo dynamic structural rearrangements during viral fusion. In addition, the conserved stretches were significantly depleted for zinc-finger antiviral protein (ZAP) binding sites, which facilitated the recognition and degradation of viral RNA. These highly conserved stretches in the SARS-CoV-2 genome were poorly conserved at the nucleotide level among closely related β-coronaviruses, thus representing ideal targets for highly specific and discriminatory diagnostic assays. Our findings highlight the role of structural constraints at both RNA and protein levels that contribute to the sequence conservation of specific genomic regions in SARS-CoV-2.
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Affiliation(s)
- Akhil Kumar
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Rishika Kaushal
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Himanshi Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Khushboo Sharma
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Manoj B Menon
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
| | - Vivekanandan P
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, New Delhi, India
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Trinity L, Stege U, Jabbari H. Tying the knot: Unraveling the intricacies of the coronavirus frameshift pseudoknot. PLoS Comput Biol 2024; 20:e1011787. [PMID: 38713726 PMCID: PMC11108256 DOI: 10.1371/journal.pcbi.1011787] [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: 12/27/2023] [Revised: 05/21/2024] [Accepted: 04/27/2024] [Indexed: 05/09/2024] Open
Abstract
Understanding and targeting functional RNA structures towards treatment of coronavirus infection can help us to prepare for novel variants of SARS-CoV-2 (the virus causing COVID-19), and any other coronaviruses that could emerge via human-to-human transmission or potential zoonotic (inter-species) events. Leveraging the fact that all coronaviruses use a mechanism known as -1 programmed ribosomal frameshifting (-1 PRF) to replicate, we apply algorithms to predict the most energetically favourable secondary structures (each nucleotide involved in at most one pairing) that may be involved in regulating the -1 PRF event in coronaviruses, especially SARS-CoV-2. We compute previously unknown most stable structure predictions for the frameshift site of coronaviruses via hierarchical folding, a biologically motivated framework where initial non-crossing structure folds first, followed by subsequent, possibly crossing (pseudoknotted), structures. Using mutual information from 181 coronavirus sequences, in conjunction with the algorithm KnotAli, we compute secondary structure predictions for the frameshift site of different coronaviruses. We then utilize the Shapify algorithm to obtain most stable SARS-CoV-2 secondary structure predictions guided by frameshift sequence-specific and genome-wide experimental data. We build on our previous secondary structure investigation of the singular SARS-CoV-2 68 nt frameshift element sequence, by using Shapify to obtain predictions for 132 extended sequences and including covariation information. Previous investigations have not applied hierarchical folding to extended length SARS-CoV-2 frameshift sequences. By doing so, we simulate the effects of ribosome interaction with the frameshift site, providing insight to biological function. We contribute in-depth discussion to contextualize secondary structure dual-graph motifs for SARS-CoV-2, highlighting the energetic stability of the previously identified 3_8 motif alongside the known dominant 3_3 and 3_6 (native-type) -1 PRF structures. Using a combination of thermodynamic methods and sequence covariation, our novel predictions suggest function of the attenuator hairpin via previously unknown pseudoknotted base pairing. While certain initial RNA folding is consistent, other pseudoknotted base pairs form which indicate potential conformational switching between the two structures.
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Affiliation(s)
- Luke Trinity
- Department of Computer Science, University of Victoria, Victoria, British Columbia, Canada
| | - Ulrike Stege
- Department of Computer Science, University of Victoria, Victoria, British Columbia, Canada
| | - Hosna Jabbari
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
- Institute on Aging and Lifelong Health, Victoria, British Columbia, Canada
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Ohyama T, Osawa T, Sekine SI, Ishii Y. NMR Studies of Genomic RNA in 3' Untranslated Region Unveil Pseudoknot Structure that Initiates Viral RNA Replication in SARS-CoV-2. JACS AU 2024; 4:1323-1333. [PMID: 38665648 PMCID: PMC11041675 DOI: 10.1021/jacsau.3c00641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/20/2024] [Accepted: 03/08/2024] [Indexed: 04/28/2024]
Abstract
In the 3' untranslated region of the SARS-CoV-2 virus RNA genome, genomic RNA replication is initiated in the highly conserved region called 3'PK, containing three stem structures (P1pk, P2, and P5). According to one proposed mechanism, P1pk and distal P2 stems switch their structure to a pseudoknot through base-pairing, thereby initiating transcription by recruiting RNA-dependent RNA polymerase complexed with nonstructural proteins (nsp)7 and nsp8. However, experimental evidence of pseudoknot formation or structural switching is unavailable. Using SARS-CoV-2 3'PK fragments, we show that 3'PK adopted stem-loop and pseudoknot forms in a mutually exclusive manner. When P1pk and P2 formed a pseudoknot, the P5 stem, which includes a sequence at the 3' end, exited from the stem-loop structure and opened up. Interaction with the nsp7/nsp8 complex destabilized the stem-loop form but did not alter the pseudoknot form. These results suggest that the interaction between the pseudoknot and nsp7/nsp8 complex transformed the 3' end of viral genomic RNA into single-stranded RNA ready for synthesis, presenting the unique pseudoknot structure as a potential pharmacological target.
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Affiliation(s)
- Takako Ohyama
- Laboratory for Advanced NMR Application and
Development, Center for Biosystems Dynamics Research, RIKEN,
1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Kanagawa,
Japan
- School of Life Science and Technology,
Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku,
Yokohama 226-8503, Kanagawa, Japan
| | - Takuo Osawa
- Laboratory for Transcription Structural Biology,
Center for Biosystems Dynamics Research, RIKEN, 1-7-22
Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Kanagawa, Japan
| | - Shun-ichi Sekine
- Laboratory for Transcription Structural Biology,
Center for Biosystems Dynamics Research, RIKEN, 1-7-22
Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Kanagawa, Japan
| | - Yoshitaka Ishii
- Laboratory for Advanced NMR Application and
Development, Center for Biosystems Dynamics Research, RIKEN,
1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Kanagawa,
Japan
- School of Life Science and Technology,
Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku,
Yokohama 226-8503, Kanagawa, Japan
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7
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Dash M, Meher P, Aditya Kumar, Satapathy SS, Namsa ND. High frequency of transition to transversion ratio in the stem region of RNA secondary structure of untranslated region of SARS-CoV-2. PeerJ 2024; 12:e16962. [PMID: 38666080 PMCID: PMC11044879 DOI: 10.7717/peerj.16962] [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: 06/22/2023] [Accepted: 01/26/2024] [Indexed: 04/28/2024] Open
Abstract
Introduction The propensity of nucleotide bases to form pairs, causes folding and the formation of secondary structure in the RNA. Therefore, purine (R): pyrimidine (Y) base-pairing is vital to maintain uniform lateral dimension in RNA secondary structure. Transversions or base substitutions between R and Y bases, are more detrimental to the stability of RNA secondary structure, than transitions derived from substitutions between A and G or C and T. The study of transversion and transition base substitutions is important to understand evolutionary mechanisms of RNA secondary structure in the 5' and 3' untranslated (UTR) regions of SARS-CoV-2. In this work, we carried out comparative analysis of transition and transversion base substitutions in the stem and loop regions of RNA secondary structure of SARS-CoV-2. Methods We have considered the experimentally determined and well documented stem and loop regions of 5' and 3' UTR regions of SARS-CoV-2 for base substitution analysis. The secondary structure comprising of stem and loop regions were visualized using the RNAfold web server. The GISAID repository was used to extract base sequence alignment of the UTR regions. Python scripts were developed for comparative analysis of transversion and transition frequencies in the stem and the loop regions. Results The results of base substitution analysis revealed a higher transition (ti) to transversion (tv) ratio (ti/tv) in the stem region of UTR of RNA secondary structure of SARS-CoV-2 reported during the early stage of the pandemic. The higher ti/tv ratio in the stem region suggested the influence of secondary structure in selecting the pattern of base substitutions. This differential pattern of ti/tv values between stem and loop regions was not observed among the Delta and Omicron variants that dominated the later stage of the pandemic. It is noteworthy that the ti/tv values in the stem and loop regions were similar among the later dominant Delta and Omicron variant strains which is to be investigated to understand the rapid evolution and global adaptation of SARS-CoV-2. Conclusion Our findings implicate the lower frequency of transversions than the transitions in the stem regions of UTRs of SARS-CoV-2. The RNA secondary structures are associated with replication, translation, and packaging, further investigations are needed to understand these base substitutions across different variants of SARS-CoV-2.
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Affiliation(s)
- Madhusmita Dash
- Department of Electronics and Communication Engineering, National Institute of Technology Arunachal Pradesh, Jote, Arunachal Pradesh, India
| | - Preetisudha Meher
- Department of Electronics and Communication Engineering, National Institute of Technology Arunachal Pradesh, Jote, Arunachal Pradesh, India
| | - Aditya Kumar
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
| | | | - Nima D. Namsa
- Department of Molecular Biology and Biotechnology, Tezpur University, Tezpur, Assam, India
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8
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Liu G, Jiang H, Chen D, Murchie AIH. Identification of Hammerhead-variant ribozyme sequences in SARS-CoV-2. Nucleic Acids Res 2024; 52:3262-3277. [PMID: 38296822 PMCID: PMC11014351 DOI: 10.1093/nar/gkae037] [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: 11/09/2023] [Revised: 01/06/2024] [Accepted: 01/11/2024] [Indexed: 02/02/2024] Open
Abstract
The SARS-CoV-2 RNA virus and variants, responsible for the COVID-19 pandemic has become endemic, raised a need for further understanding of the viral genome and biology. Despite vast research on SARS-CoV-2, no ribozymes have been found in the virus genome. Here we report the identification of 39 Hammerhead-variant ribozyme sequences (CoV-HHRz) in SARS-CoV-2. These sequences are highly conserved within SARS-CoV-2 variants but show large diversity among other coronaviruses. In vitro CoV-HHRz sequences possess the characteristics of typical ribozymes; cleavage is pH and ion dependent, although their activity is relatively low and Mn2+ is required for cleavage. The cleavage sites of four CoV-HHRz coincide with the breakpoint of expressed subgenomic RNA (sgRNAs) in SARS-CoV-2 transcriptome data suggesting in vivo activity. The CoV-HHRz are involved in processing sgRNAs for ORF7b, ORF 10 and ORF1ab nsp13 which are essential for viral packaging and life cycle.
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Affiliation(s)
- Getong Liu
- Shanghai Pudong Hospital, Fudan University Pudong Medical Center and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Hengyi Jiang
- Shanghai Pudong Hospital, Fudan University Pudong Medical Center and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Dongrong Chen
- Shanghai Pudong Hospital, Fudan University Pudong Medical Center and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
| | - Alastair I H Murchie
- Shanghai Pudong Hospital, Fudan University Pudong Medical Center and Institutes of Biomedical Sciences, Shanghai Medical College, Key Laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai 200032, China
- Key Laboratory of Metabolism and Molecular Medicine, Ministry of Education, School of Basic Medical Sciences, Fudan University, Shanghai 200032, China
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9
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Ziesel A, Jabbari H. Unveiling hidden structural patterns in the SARS-CoV-2 genome: Computational insights and comparative analysis. PLoS One 2024; 19:e0298164. [PMID: 38574063 PMCID: PMC10994416 DOI: 10.1371/journal.pone.0298164] [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: 10/06/2023] [Accepted: 01/19/2024] [Indexed: 04/06/2024] Open
Abstract
SARS-CoV-2, the causative agent of COVID-19, is known to exhibit secondary structures in its 5' and 3' untranslated regions, along with the frameshifting stimulatory element situated between ORF1a and 1b. To identify additional regions containing conserved structures, we utilized a multiple sequence alignment with related coronaviruses as a starting point. We applied a computational pipeline developed for identifying non-coding RNA elements. Our pipeline employed three different RNA structural prediction approaches. We identified forty genomic regions likely to harbor structures, with ten of them showing three-way consensus substructure predictions among our predictive utilities. We conducted intracomparisons of the predictive utilities within the pipeline and intercomparisons with four previously published SARS-CoV-2 structural datasets. While there was limited agreement on the precise structure, different approaches seemed to converge on regions likely to contain structures in the viral genome. By comparing and combining various computational approaches, we can predict regions most likely to form structures, as well as a probable structure or ensemble of structures. These predictions can be used to guide surveillance, prophylactic measures, or therapeutic efforts. Data and scripts employed in this study may be found at https://doi.org/10.5281/zenodo.8298680.
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Affiliation(s)
- Alison Ziesel
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Hosna Jabbari
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
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10
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Steiner S, Kratzel A, Barut GT, Lang RM, Aguiar Moreira E, Thomann L, Kelly JN, Thiel V. SARS-CoV-2 biology and host interactions. Nat Rev Microbiol 2024; 22:206-225. [PMID: 38225365 DOI: 10.1038/s41579-023-01003-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2023] [Indexed: 01/17/2024]
Abstract
The zoonotic emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the ensuing coronavirus disease 2019 (COVID-19) pandemic have profoundly affected our society. The rapid spread and continuous evolution of new SARS-CoV-2 variants continue to threaten global public health. Recent scientific advances have dissected many of the molecular and cellular mechanisms involved in coronavirus infections, and large-scale screens have uncovered novel host-cell factors that are vitally important for the virus life cycle. In this Review, we provide an updated summary of the SARS-CoV-2 life cycle, gene function and virus-host interactions, including recent landmark findings on general aspects of coronavirus biology and newly discovered host factors necessary for virus replication.
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Affiliation(s)
- Silvio Steiner
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Annika Kratzel
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - G Tuba Barut
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Reto M Lang
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Etori Aguiar Moreira
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Lisa Thomann
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Jenna N Kelly
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- European Virus Bioinformatics Center, Jena, Germany
| | - Volker Thiel
- Institute of Virology and Immunology, Bern and Mittelhäusern, Bern, Switzerland.
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland.
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland.
- European Virus Bioinformatics Center, Jena, Germany.
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11
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Irving PS, Weeks KM. RNAvigate: efficient exploration of RNA chemical probing datasets. Nucleic Acids Res 2024; 52:2231-2241. [PMID: 38348910 PMCID: PMC10954457 DOI: 10.1093/nar/gkae089] [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: 04/30/2023] [Revised: 01/19/2024] [Accepted: 01/30/2024] [Indexed: 02/27/2024] Open
Abstract
Chemical probing technologies enable high-throughput examination of diverse structural features of RNA, including local nucleotide flexibility, RNA secondary structure, protein and ligand binding, through-space interaction networks, and multistate structural ensembles. Deep understanding of RNA structure-function relationships typically requires evaluating a system under structure- and function-altering conditions, linking these data with additional information, and visualizing multilayered relationships. Current platforms lack the broad accessibility, flexibility and efficiency needed to iterate on integrative analyses of these diverse, complex data. Here, we share the RNA visualization and graphical analysis toolset RNAvigate, a straightforward and flexible Python library that automatically parses 21 standard file formats (primary sequence annotations, per- and internucleotide data, and secondary and tertiary structures) and outputs 18 plot types. RNAvigate enables efficient exploration of nuanced relationships between multiple layers of RNA structure information and across multiple experimental conditions. Compatibility with Jupyter notebooks enables nonburdensome, reproducible, transparent and organized sharing of multistep analyses and data visualization strategies. RNAvigate simplifies and accelerates discovery and characterization of RNA-centric functions in biology.
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Affiliation(s)
- Patrick S Irving
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
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12
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Kretsch RC, Xu L, Zheludev IN, Zhou X, Huang R, Nye G, Li S, Zhang K, Chiu W, Das R. Tertiary folds of the SL5 RNA from the 5' proximal region of SARS-CoV-2 and related coronaviruses. Proc Natl Acad Sci U S A 2024; 121:e2320493121. [PMID: 38427602 DOI: 10.1073/pnas.2320493121] [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: 11/26/2023] [Accepted: 01/05/2024] [Indexed: 03/03/2024] Open
Abstract
Coronavirus genomes sequester their start codons within stem-loop 5 (SL5), a structured, 5' genomic RNA element. In most alpha- and betacoronaviruses, the secondary structure of SL5 is predicted to contain a four-way junction of helical stems, some of which are capped with UUYYGU hexaloops. Here, using cryogenic electron microscopy (cryo-EM) and computational modeling with biochemically determined secondary structures, we present three-dimensional structures of SL5 from six coronaviruses. The SL5 domain of betacoronavirus severe-acute-respiratory-syndrome-related coronavirus 2 (SARS-CoV-2), resolved at 4.7 Å resolution, exhibits a T-shaped structure, with its UUYYGU hexaloops at opposing ends of a coaxial stack, the T's "arms." Further analysis of SL5 domains from SARS-CoV-1 and MERS (7.1 and 6.4 to 6.9 Å resolution, respectively) indicate that the junction geometry and inter-hexaloop distances are conserved features across these human-infecting betacoronaviruses. The MERS SL5 domain displays an additional tertiary interaction, which is also observed in the non-human-infecting betacoronavirus BtCoV-HKU5 (5.9 to 8.0 Å resolution). SL5s from human-infecting alphacoronaviruses, HCoV-229E and HCoV-NL63 (6.5 and 8.4 to 9.0 Å resolution, respectively), exhibit the same coaxial stacks, including the UUYYGU-capped arms, but with a phylogenetically distinct crossing angle, an X-shape. As such, all SL5 domains studied herein fold into stable tertiary structures with cross-genus similarities and notable differences, with implications for potential protein-binding modes and therapeutic targets.
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Affiliation(s)
| | - Lily Xu
- Department of Microbiology and Immunology, Stanford University, Stanford, CA 94305
| | - Ivan N Zheludev
- Department of Biochemistry, Stanford University, Stanford, CA 94305
| | - Xueting Zhou
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA 94305
| | - Rui Huang
- Department of Biochemistry, Stanford University, Stanford, CA 94305
| | - Grace Nye
- Department of Biochemistry, Stanford University, Stanford, CA 94305
| | - Shanshan Li
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Kaiming Zhang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Wah Chiu
- Biophysics Program, Stanford University, Stanford, CA 94305
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA 94305
- CryoEM and Bioimaging Division, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025
| | - Rhiju Das
- Biophysics Program, Stanford University, Stanford, CA 94305
- Department of Biochemistry, Stanford University, Stanford, CA 94305
- HHMI, Stanford University, Stanford, CA 94305
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13
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Karousis ED. The art of hijacking: how Nsp1 impacts host gene expression during coronaviral infections. Biochem Soc Trans 2024; 52:481-490. [PMID: 38385526 PMCID: PMC10903449 DOI: 10.1042/bst20231119] [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: 01/18/2024] [Revised: 02/14/2024] [Accepted: 02/14/2024] [Indexed: 02/23/2024]
Abstract
Non-structural protein 1 (Nsp1) is one of the first proteins produced during coronaviral infections. It plays a pivotal role in hijacking and rendering the host gene expression under the service of the virus. With a focus on SARS-CoV-2, this review presents how Nsp1 selectively inhibits host protein synthesis and induces mRNA degradation of host but not viral mRNAs and blocks nuclear mRNA export. The clinical implications of this protein are highlighted by showcasing the pathogenic role of Nsp1 through the repression of interferon expression pathways and the features of viral variants with mutations in the Nsp1 coding sequence. The ability of SARS-CoV-2 Nsp1 to hinder host immune responses at an early step, the absence of homology to any human proteins, and the availability of structural information render this viral protein an ideal drug target with therapeutic potential.
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Affiliation(s)
- Evangelos D Karousis
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
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14
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Zhao H, Cai Z, Rao J, Wu D, Ji L, Ye R, Wang D, Chen J, Cao C, Hu N, Shu T, Zhu P, Wang J, Zhou X, Xue Y. SARS-CoV-2 RNA stabilizes host mRNAs to elicit immunopathogenesis. Mol Cell 2024; 84:490-505.e9. [PMID: 38128540 DOI: 10.1016/j.molcel.2023.11.032] [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: 02/21/2023] [Revised: 10/09/2023] [Accepted: 11/22/2023] [Indexed: 12/23/2023]
Abstract
SARS-CoV-2 RNA interacts with host factors to suppress interferon responses and simultaneously induces cytokine release to drive the development of severe coronavirus disease 2019 (COVID-19). However, how SARS-CoV-2 hijacks host RNAs to elicit such imbalanced immune responses remains elusive. Here, we analyzed SARS-CoV-2 RNA in situ structures and interactions in infected cells and patient lung samples using RIC-seq. We discovered that SARS-CoV-2 RNA forms 2,095 potential duplexes with the 3' UTRs of 205 host mRNAs to increase their stability by recruiting RNA-binding protein YBX3 in A549 cells. Disrupting the SARS-CoV-2-to-host RNA duplex or knocking down YBX3 decreased host mRNA stability and reduced viral replication. Among SARS-CoV-2-stabilized host targets, NFKBIZ was crucial for promoting cytokine production and reducing interferon responses, probably contributing to cytokine storm induction. Our study uncovers the crucial roles of RNA-RNA interactions in the immunopathogenesis of RNA viruses such as SARS-CoV-2 and provides valuable host targets for drug development.
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Affiliation(s)
- Hailian Zhao
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaokui Cai
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jian Rao
- National Health Commission of the People's Republic of China Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Di Wu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Lei Ji
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Rong Ye
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Di Wang
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Juan Chen
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Changchang Cao
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Naijing Hu
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Ting Shu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China
| | - Ping Zhu
- Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital, Southern Medical University, Guangzhou 510100, China
| | - Jianwei Wang
- National Health Commission of the People's Republic of China Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China.
| | - Xi Zhou
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
| | - Yuanchao Xue
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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15
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Bose R, Saleem I, Mustoe AM. Causes, functions, and therapeutic possibilities of RNA secondary structure ensembles and alternative states. Cell Chem Biol 2024; 31:17-35. [PMID: 38199037 PMCID: PMC10842484 DOI: 10.1016/j.chembiol.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/21/2023] [Accepted: 12/12/2023] [Indexed: 01/12/2024]
Abstract
RNA secondary structure plays essential roles in encoding RNA regulatory fate and function. Most RNAs populate ensembles of alternatively paired states and are continually unfolded and refolded by cellular processes. Measuring these structural ensembles and their contributions to cellular function has traditionally posed major challenges, but new methods and conceptual frameworks are beginning to fill this void. In this review, we provide a mechanism- and function-centric compendium of the roles of RNA secondary structural ensembles and minority states in regulating the RNA life cycle, from transcription to degradation. We further explore how dysregulation of RNA structural ensembles contributes to human disease and discuss the potential of drugging alternative RNA states to therapeutically modulate RNA activity. The emerging paradigm of RNA structural ensembles as central to RNA function provides a foundation for a deeper understanding of RNA biology and new therapeutic possibilities.
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Affiliation(s)
- Ritwika Bose
- Therapeutic Innovation Center (THINC), Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Irfana Saleem
- Therapeutic Innovation Center (THINC), Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA
| | - Anthony M Mustoe
- Therapeutic Innovation Center (THINC), Department of Biochemistry and Molecular Pharmacology, Baylor College of Medicine, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.
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16
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Wang W, Liu F, Ugalde MV, Pyle AM. A compact regulatory RNA element in mouse Hsp70 mRNA. NAR MOLECULAR MEDICINE 2024; 1:ugae002. [PMID: 38318492 PMCID: PMC10840451 DOI: 10.1093/narmme/ugae002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 01/08/2024] [Accepted: 01/24/2024] [Indexed: 02/07/2024]
Abstract
Hsp70 (70 kDa heat shock protein) performs molecular chaperone functions by assisting the folding of newly synthesized and misfolded proteins, thereby counteracting various cell stresses and preventing multiple diseases, including neurodegenerative disorders and cancers. It is well established that, immediately after heat shock, Hsp70 gene expression is mediated by a canonical mechanism of cap-dependent translation. However, the molecular mechanism of Hsp70 expression during heat shock remains elusive. Intriguingly, the 5' end of Hsp70 messenger RNA (mRNA) appears to form a compact structure with the potential to regulate protein expression in a cap-independent manner. Here, we determined the minimal length of the mHsp70 5'-terminal mRNA sequence that is required for RNA folding into a highly compact structure. This span of this RNA element was mapped and the secondary structure characterized by chemical probing, resulting in a secondary structural model that includes multiple stable stems, including one containing the canonical start codon. All of these components, including a short stretch of the 5' open reading frame (ORF), were shown to be vital for RNA folding. This work provides a structural basis for future investigations on the role of translational regulatory structures in the 5' untranslated region and ORF sequences of Hsp70 during heat shock.
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Affiliation(s)
- Wenshuai Wang
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Fei Liu
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Maria Vera Ugalde
- Department of Biochemistry. McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Anna Marie Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
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17
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Karousis ED, Schubert K, Ban N. Coronavirus takeover of host cell translation and intracellular antiviral response: a molecular perspective. EMBO J 2024; 43:151-167. [PMID: 38200146 PMCID: PMC10897431 DOI: 10.1038/s44318-023-00019-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 11/01/2023] [Accepted: 11/24/2023] [Indexed: 01/12/2024] Open
Abstract
Coronaviruses are a group of related RNA viruses that cause respiratory diseases in humans and animals. Understanding the mechanisms of translation regulation during coronaviral infections is critical for developing antiviral therapies and preventing viral spread. Translation of the viral single-stranded RNA genome in the host cell cytoplasm is an essential step in the life cycle of coronaviruses, which affects the cellular mRNA translation landscape in many ways. Here we discuss various viral strategies of translation control, including how members of the Betacoronavirus genus shut down host cell translation and suppress host innate immune functions, as well as the role of the viral non-structural protein 1 (Nsp1) in the process. We also outline the fate of viral RNA, considering stress response mechanisms triggered in infected cells, and describe how unique viral RNA features contribute to programmed ribosomal -1 frameshifting, RNA editing, and translation shutdown evasion.
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Affiliation(s)
- Evangelos D Karousis
- Multidisciplinary Center for Infectious Diseases, University of Bern, Bern, Switzerland
- Department of Chemistry and Biochemistry, University of Bern, Bern, Switzerland
| | - Katharina Schubert
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland.
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18
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Adly AN, Bi M, Carlson CR, Syed AM, Ciling A, Doudna JA, Cheng Y, Morgan DO. Assembly of SARS-CoV-2 ribonucleosomes by truncated N ∗ variant of the nucleocapsid protein. J Biol Chem 2023; 299:105362. [PMID: 37863261 PMCID: PMC10665939 DOI: 10.1016/j.jbc.2023.105362] [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: 08/18/2023] [Revised: 10/05/2023] [Accepted: 10/11/2023] [Indexed: 10/22/2023] Open
Abstract
The nucleocapsid (N) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) compacts the RNA genome into viral ribonucleoprotein (vRNP) complexes within virions. Assembly of vRNPs is inhibited by phosphorylation of the N protein serine/arginine (SR) region. Several SARS-CoV-2 variants of concern carry N protein mutations that reduce phosphorylation and enhance the efficiency of viral packaging. Variants of the dominant B.1.1 viral lineage also encode a truncated N protein, termed N∗ or Δ(1-209), that mediates genome packaging despite lacking the N-terminal RNA-binding domain and SR region. Here, we use mass photometry and negative stain electron microscopy to show that purified Δ(1-209) and viral RNA assemble into vRNPs that are remarkably similar in size and shape to those formed with full-length N protein. We show that assembly of Δ(1-209) vRNPs requires the leucine-rich helix of the central disordered region and that this helix promotes N protein oligomerization. We also find that fusion of a phosphomimetic SR region to Δ(1-209) inhibits RNA binding and vRNP assembly. Our results provide new insights into the mechanisms by which RNA binding promotes N protein self-association and vRNP assembly, and how this process is modulated by phosphorylation.
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Affiliation(s)
- Armin N Adly
- Department of Physiology, University of California, San Francisco, California, USA
| | - Maxine Bi
- Department of Biochemistry & Biophysics, University of California, San Francisco, California, USA
| | | | - Abdullah M Syed
- J. David Gladstone Institutes, San Francisco, California, USA
| | - Alison Ciling
- J. David Gladstone Institutes, San Francisco, California, USA
| | - Jennifer A Doudna
- J. David Gladstone Institutes, San Francisco, California, USA; Department of Molecular and Cell Biology, University of California, Berkeley, California, USA; Howard Hughes Medical Institute, University of California, Berkeley, California, USA; Innovative Genomics Institute, University of California, Berkeley, California, USA; California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, California, USA; MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Yifan Cheng
- Department of Biochemistry & Biophysics, University of California, San Francisco, California, USA; Howard Hughes Medical Institute, University of California, San Francisco, California, USA
| | - David O Morgan
- Department of Physiology, University of California, San Francisco, California, USA.
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19
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Kretsch RC, Andersen ES, Bujnicki JM, Chiu W, Das R, Luo B, Masquida B, McRae EK, Schroeder GM, Su Z, Wedekind JE, Xu L, Zhang K, Zheludev IN, Moult J, Kryshtafovych A. RNA target highlights in CASP15: Evaluation of predicted models by structure providers. Proteins 2023; 91:1600-1615. [PMID: 37466021 PMCID: PMC10792523 DOI: 10.1002/prot.26550] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/16/2023] [Accepted: 06/26/2023] [Indexed: 07/20/2023]
Abstract
The first RNA category of the Critical Assessment of Techniques for Structure Prediction competition was only made possible because of the scientists who provided experimental structures to challenge the predictors. In this article, these scientists offer a unique and valuable analysis of both the successes and areas for improvement in the predicted models. All 10 RNA-only targets yielded predictions topologically similar to experimentally determined structures. For one target, experimentalists were able to phase their x-ray diffraction data by molecular replacement, showing a potential application of structure predictions for RNA structural biologists. Recommended areas for improvement include: enhancing the accuracy in local interaction predictions and increased consideration of the experimental conditions such as multimerization, structure determination method, and time along folding pathways. The prediction of RNA-protein complexes remains the most significant challenge. Finally, given the intrinsic flexibility of many RNAs, we propose the consideration of ensemble models.
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Affiliation(s)
- Rachael C. Kretsch
- Biophysics Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Ebbe S. Andersen
- Interdisciplinary Nanoscience Center and Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Janusz M. Bujnicki
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Wah Chiu
- Biophysics Program, Stanford University School of Medicine, Stanford, CA, USA
- Department of Bioengineering and James H. Clark Center, Stanford University, Stanford, CA, USA
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Menlo Park, CA, USA
| | - Rhiju Das
- Biophysics Program, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
| | - Bingnan Luo
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610044, Sichuan, China
| | - Benoît Masquida
- UMR 7156, CNRS – Universite de Strasbourg, Strasbourg, France
| | - Ewan K.S. McRae
- Center for RNA Therapeutics, Houston Methodist Research Institute, Houston, TX 77030, USA
| | - Griffin M. Schroeder
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Zhaoming Su
- The State Key Laboratory of Biotherapy, Frontiers Medical Center of Tianfu Jincheng Laboratory, Department of Geriatrics and National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu 610044, Sichuan, China
| | - Joseph E. Wedekind
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
- Center for RNA Biology, University of Rochester School of Medicine and Dentistry, Rochester, NY, 14642, USA
| | - Lily Xu
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Kaiming Zhang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Ivan N. Zheludev
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - John Moult
- Department of Cell Biology and Molecular Genetics, Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland, USA
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20
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Dauksaite V, Tas A, Wachowius F, Spruit A, van Hemert MJ, Snijder EJ, van der Veer EP, van Zonneveld AJ. Highly Potent Antisense Oligonucleotides Locked Nucleic Acid Gapmers Targeting the SARS-CoV-2 RNA Genome. Nucleic Acid Ther 2023; 33:381-385. [PMID: 37782140 DOI: 10.1089/nat.2023.0012] [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: 10/03/2023] Open
Abstract
The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused the current worldwide pandemic and the associated coronavirus disease 2019 with potentially lethal outcome. Although effective vaccines strongly contributed to reduce disease severity, establishing a toolbox to control current and newly emerging coronaviruses of epidemic concern requires the development of novel therapeutic compounds, to treat severely infected individuals and to prevent virus transmission. Here we present a therapeutic strategy targeting the SARS-CoV-2 RNA genome using antisense oligonucleotides (ASOs). We demonstrate that selected locked nucleic acid gapmers have the potency to reduce the in vitro intracellular viral load by up to 96%. Our promising results strongly support the case for further development of our preselected ASOs as therapeutic or prophylactic antiviral agents.
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Affiliation(s)
- Vita Dauksaite
- Einthoven Laboratory for Vascular and Regenerative Medicine, Department of Internal Medicine (Nephrology), Leiden University Medical Centre, Leiden, The Netherlands
| | - Ali Tas
- Department of Medical Microbiology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Anouk Spruit
- Einthoven Laboratory for Vascular and Regenerative Medicine, Department of Internal Medicine (Nephrology), Leiden University Medical Centre, Leiden, The Netherlands
| | - Martijn J van Hemert
- Department of Medical Microbiology, Leiden University Medical Centre, Leiden, The Netherlands
| | - Eric J Snijder
- Department of Medical Microbiology, Leiden University Medical Centre, Leiden, The Netherlands
| | | | - Anton Jan van Zonneveld
- Einthoven Laboratory for Vascular and Regenerative Medicine, Department of Internal Medicine (Nephrology), Leiden University Medical Centre, Leiden, The Netherlands
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21
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Kretsch RC, Xu L, Zheludev IN, Zhou X, Huang R, Nye G, Li S, Zhang K, Chiu W, Das R. Tertiary folds of the SL5 RNA from the 5' proximal region of SARS-CoV-2 and related coronaviruses. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.22.567964. [PMID: 38076883 PMCID: PMC10705266 DOI: 10.1101/2023.11.22.567964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Coronavirus genomes sequester their start codons within stem-loop 5 (SL5), a structured, 5' genomic RNA element. In most alpha- and betacoronaviruses, the secondary structure of SL5 is predicted to contain a four-way junction of helical stems, some of which are capped with UUYYGU hexaloops. Here, using cryogenic electron microscopy (cryo-EM) and computational modeling with biochemically-determined secondary structures, we present three-dimensional structures of SL5 from six coronaviruses. The SL5 domain of betacoronavirus SARS-CoV-2, resolved at 4.7 Å resolution, exhibits a T-shaped structure, with its UUYYGU hexaloops at opposing ends of a coaxial stack, the T's "arms." Further analysis of SL5 domains from SARS-CoV-1 and MERS (7.1 and 6.4-6.9 Å resolution, respectively) indicate that the junction geometry and inter-hexaloop distances are conserved features across the studied human-infecting betacoronaviruses. The MERS SL5 domain displays an additional tertiary interaction, which is also observed in the non-human-infecting betacoronavirus BtCoV-HKU5 (5.9-8.0 Å resolution). SL5s from human-infecting alphacoronaviruses, HCoV-229E and HCoV-NL63 (6.5 and 8.4-9.0 Å resolution, respectively), exhibit the same coaxial stacks, including the UUYYGU-capped arms, but with a phylogenetically distinct crossing angle, an X-shape. As such, all SL5 domains studied herein fold into stable tertiary structures with cross-genus similarities, with implications for potential protein-binding modes and therapeutic targets.
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Affiliation(s)
| | - Lily Xu
- Department of Microbiology and Immunology, Stanford University, Stanford, CA, USA
| | - Ivan N. Zheludev
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Xueting Zhou
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, USA
| | - Rui Huang
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Grace Nye
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Shanshan Li
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Kaiming Zhang
- Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Wah Chiu
- Biophysics Program, Stanford University, Stanford, CA, USA
- Department of Bioengineering, James H. Clark Center, Stanford University, Stanford, CA, USA
- CryoEM and Bioimaging Division, Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA, USA
| | - Rhiju Das
- Biophysics Program, Stanford University, Stanford, CA, USA
- Department of Biochemistry, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford, CA, USA
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22
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Small GI, Fedorova O, Olinares PDB, Chandanani J, Banerjee A, Choi YJ, Molina H, Chait BT, Darst SA, Campbell EA. Structural and functional insights into the enzymatic plasticity of the SARS-CoV-2 NiRAN domain. Mol Cell 2023; 83:3921-3930.e7. [PMID: 37890482 PMCID: PMC10843261 DOI: 10.1016/j.molcel.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 08/28/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023]
Abstract
The enzymatic activity of the SARS-CoV-2 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain is essential for viral propagation, with three distinct activities associated with modification of the nsp9 N terminus, NMPylation, RNAylation, and deRNAylation/capping via a GDP-polyribonucleotidyltransferase reaction. The latter two activities comprise an unconventional mechanism for initiating viral RNA 5' cap formation, while the role of NMPylation is unclear. The structural mechanisms for these diverse enzymatic activities have not been properly delineated. Here, we determine high-resolution cryoelectron microscopy (cryo-EM) structures of catalytic intermediates for the NMPylation and deRNAylation/capping reactions, revealing diverse nucleotide binding poses and divalent metal ion coordination sites to promote its repertoire of activities. The deRNAylation/capping structure explains why GDP is a preferred substrate for the capping reaction over GTP. Altogether, these findings enhance our understanding of the promiscuous coronaviral NiRAN domain, a therapeutic target, and provide an accurate structural platform for drug development.
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Affiliation(s)
- Gabriel I Small
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Olga Fedorova
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Joshua Chandanani
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Anoosha Banerjee
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Tri-Institutional Program in Chemical Biology, The Rockefeller University, New York, New York, USA
| | - Young Joo Choi
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA.
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23
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Tang Z, Hegde S, Hao S, Selvaraju M, Qiu J, Wang J. Chemical-guided SHAPE sequencing (cgSHAPE-seq) informs the binding site of RNA-degrading chimeras targeting SARS-CoV-2 5' untranslated region. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535453. [PMID: 37066172 PMCID: PMC10103992 DOI: 10.1101/2023.04.03.535453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
One of the hallmarks of RNA viruses is highly structured untranslated regions (UTRs) in their genomes. These conserved RNA structures are often essential for viral replication, transcription, or translation. In this report, we discovered and optimized a new type of coumarin derivatives, such as C30 and C34, which bind to a four-way RNA helix called SL5 in the 5' UTR of the SARS-CoV-2 RNA genome. To locate the binding site, we developed a novel sequencing-based method namely cgSHAPE-seq, in which the acylating chemical probe was directed to crosslink with the 2'-OH groups of ribose at the ligand binding site. This crosslinked RNA could then create read-through mutations during reverse transcription (i.e., primer extension) at single-nucleotide resolution to uncover the acylation locations. cgSHAPE-seq unambiguously determined that a bulged G in SL5 was the primary binding site of C30 in the SARS-CoV-2 5' UTR, which was validated through mutagenesis and in vitro binding experiments. C30 was further used as a warhead in RNA-degrading chimeras to reduce viral RNA expression levels. We demonstrated that replacing the acylating moiety in the cgSHAPE probe with ribonuclease L recruiter (RLR) moieties yielded RNA degraders active in the in vitro RNase L degradation assay and SARS-CoV-2 5' UTR expressing cells. We further explored another RLR conjugation site on the E ring of C30/C34 and discovered improved RNA degradation activities in vitro and in cells. The optimized RNA-degrading chimera C64 inhibited live virus replication in lung epithelial carcinoma cells.
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Affiliation(s)
- Zhichao Tang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
| | - Shalakha Hegde
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
| | - Siyuan Hao
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | | | - Jianming Qiu
- Department of Microbiology, Molecular Genetics and Immunology, University of Kansas Medical Center, Kansas City, KS, USA
| | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, USA
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24
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Zhang H, Li S, Dai N, Zhang L, Mathews DH, Huang L. LinearCoFold and LinearCoPartition: linear-time algorithms for secondary structure prediction of interacting RNA molecules. Nucleic Acids Res 2023; 51:e94. [PMID: 37650626 PMCID: PMC10570024 DOI: 10.1093/nar/gkad664] [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: 12/01/2022] [Revised: 06/15/2023] [Accepted: 08/17/2023] [Indexed: 09/01/2023] Open
Abstract
Many RNAs function through RNA-RNA interactions. Fast and reliable RNA structure prediction with consideration of RNA-RNA interaction is useful, however, existing tools are either too simplistic or too slow. To address this issue, we present LinearCoFold, which approximates the complete minimum free energy structure of two strands in linear time, and LinearCoPartition, which approximates the cofolding partition function and base pairing probabilities in linear time. LinearCoFold and LinearCoPartition are orders of magnitude faster than RNAcofold. For example, on a sequence pair with combined length of 26,190 nt, LinearCoFold is 86.8× faster than RNAcofold MFE mode, and LinearCoPartition is 642.3× faster than RNAcofold partition function mode. Surprisingly, LinearCoFold and LinearCoPartition's predictions have higher PPV and sensitivity of intermolecular base pairs. Furthermore, we apply LinearCoFold to predict the RNA-RNA interaction between SARS-CoV-2 genomic RNA (gRNA) and human U4 small nuclear RNA (snRNA), which has been experimentally studied, and observe that LinearCoFold's prediction correlates better with the wet lab results than RNAcofold's.
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Affiliation(s)
- He Zhang
- Baidu Research, Sunnyvale, CA, USA
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - Sizhen Li
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - Ning Dai
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - Liang Zhang
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics,Rochester, NY 14642, USA
- Center for RNA Biology, Rochester, NY 14642, USA
- Department of Biostatistics & Computational Biology, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Liang Huang
- School of Electrical Engineering & Computer Science, Oregon State University, Corvallis, OR, USA
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25
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Abstract
Protein synthesis by the ribosome is the final stage of biological information transfer and represents an irreversible commitment to gene expression. Accurate translation of messenger RNA is therefore essential to all life, and spontaneous errors by the translational machinery are highly infrequent (∼1/100,000 codons). Programmed -1 ribosomal frameshifting (-1PRF) is a mechanism in which the elongating ribosome is induced at high frequency to slip backward by one nucleotide at a defined position and to continue translation in the new reading frame. This is exploited as a translational regulation strategy by hundreds of RNA viruses, which rely on -1PRF during genome translation to control the stoichiometry of viral proteins. While early investigations of -1PRF focused on virological and biochemical aspects, the application of X-ray crystallography and cryo-electron microscopy (cryo-EM), and the advent of deep sequencing and single-molecule approaches have revealed unexpected structural diversity and mechanistic complexity. Molecular players from several model systems have now been characterized in detail, both in isolation and, more recently, in the context of the elongating ribosome. Here we provide a summary of recent advances and discuss to what extent a general model for -1PRF remains a useful way of thinking.
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Affiliation(s)
- Chris H Hill
- York Structural Biology Laboratory, York Biomedical Research Institute, Department of Biology, University of York, York, United Kingdom;
| | - Ian Brierley
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom;
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26
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Awad AM, Hansen K, Del Rio D, Flores D, Barghash RF, Kakkola L, Julkunen I, Awad K. Insights into COVID-19: Perspectives on Drug Remedies and Host Cell Responses. Biomolecules 2023; 13:1452. [PMID: 37892134 PMCID: PMC10604481 DOI: 10.3390/biom13101452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/29/2023] Open
Abstract
In light of the COVID-19 global pandemic caused by SARS-CoV-2, ongoing research has centered on minimizing viral spread either by stopping viral entry or inhibiting viral replication. Repurposing antiviral drugs, typically nucleoside analogs, has proven successful at inhibiting virus replication. This review summarizes current information regarding coronavirus classification and characterization and presents the broad clinical consequences of SARS-CoV-2 activation of the angiotensin-converting enzyme 2 (ACE2) receptor expressed in different human cell types. It provides publicly available knowledge on the chemical nature of proposed therapeutics and their target biomolecules to assist in the identification of potentially new drugs for the treatment of SARS-CoV-2 infection.
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Affiliation(s)
- Ahmed M. Awad
- Department of Chemistry, California State University Channel Islands, Camarillo, CA 93012, USA
| | - Kamryn Hansen
- Department of Chemistry, California State University Channel Islands, Camarillo, CA 93012, USA
| | - Diana Del Rio
- Department of Chemistry, California State University Channel Islands, Camarillo, CA 93012, USA
| | - Derek Flores
- Department of Chemistry, California State University Channel Islands, Camarillo, CA 93012, USA
| | - Reham F. Barghash
- Institute of Chemical Industries Research, National Research Centre, Dokki, Cairo 12622, Egypt
| | - Laura Kakkola
- Institute of Biomedicine, Faculty of Medicine, University of Turku, 20014 Turku, Finland
| | - Ilkka Julkunen
- Institute of Biomedicine, Faculty of Medicine, University of Turku, 20014 Turku, Finland
- Clinical Microbiology, Turku University Hospital, 20521 Turku, Finland
| | - Kareem Awad
- Institute of Biomedicine, Faculty of Medicine, University of Turku, 20014 Turku, Finland
- Department of Therapeutic Chemistry, Institute of Pharmaceutical and Drug Industries Research, National Research Center, Dokki, Cairo 12622, Egypt
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27
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Small GI, Fedorova O, Olinares PDB, Chandanani J, Banerjee A, Choi YJ, Molina H, Chait B, Darst SA, Campbell EA. Structural and functional insights into the enzymatic plasticity of the SARS-CoV-2 NiRAN Domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.25.558837. [PMID: 37808858 PMCID: PMC10557602 DOI: 10.1101/2023.09.25.558837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
The enzymatic activity of the SARS-CoV-2 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain is essential for viral propagation, with three distinct activities associated with modification of the nsp9 N-terminus, NMPylation, RNAylation, and deRNAylation/capping via a GDP-polyribonucleotidyltransferase reaction. The latter two activities comprise an unconventional mechanism for initiating viral RNA 5'-cap formation, while the role of NMPylation is unclear. The structural mechanisms for these diverse enzymatic activities have not been properly delineated. Here we determine high-resolution cryo-electron microscopy structures of catalytic intermediates for the NMPylation and deRNAylation/capping reactions, revealing diverse nucleotide binding poses and divalent metal ion coordination sites to promote its repertoire of activities. The deRNAylation/capping structure explains why GDP is a preferred substrate for the capping reaction over GTP. Altogether, these findings enhance our understanding of the promiscuous coronaviral NiRAN domain, a therapeutic target, and provide an accurate structural platform for drug development.
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Affiliation(s)
- Gabriel I Small
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Olga Fedorova
- Department of Chemistry and Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA
| | - Paul Dominic B Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Joshua Chandanani
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Anoosha Banerjee
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Young Joo Choi
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Present address: University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA
| | - Henrik Molina
- Proteomics Resource Center, The Rockefeller University, New York, NY 10065, USA
| | - Brian Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA
| | - Seth A Darst
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
| | - Elizabeth A Campbell
- Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
- Lead contact:
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28
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Bloom JD, Neher RA. Fitness effects of mutations to SARS-CoV-2 proteins. Virus Evol 2023; 9:vead055. [PMID: 37727875 PMCID: PMC10506532 DOI: 10.1093/ve/vead055] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 08/08/2023] [Accepted: 08/22/2023] [Indexed: 09/21/2023] Open
Abstract
Knowledge of the fitness effects of mutations to SARS-CoV-2 can inform assessment of new variants, design of therapeutics resistant to escape, and understanding of the functions of viral proteins. However, experimentally measuring effects of mutations is challenging: we lack tractable lab assays for many SARS-CoV-2 proteins, and comprehensive deep mutational scanning has been applied to only two SARS-CoV-2 proteins. Here, we develop an approach that leverages millions of publicly available SARS-CoV-2 sequences to estimate effects of mutations. We first calculate how many independent occurrences of each mutation are expected to be observed along the SARS-CoV-2 phylogeny in the absence of selection. We then compare these expected observations to the actual observations to estimate the effect of each mutation. These estimates correlate well with deep mutational scanning measurements. For most genes, synonymous mutations are nearly neutral, stop-codon mutations are deleterious, and amino acid mutations have a range of effects. However, some viral accessory proteins are under little to no selection. We provide interactive visualizations of effects of mutations to all SARS-CoV-2 proteins (https://jbloomlab.github.io/SARS2-mut-fitness/). The framework we describe is applicable to any virus for which the number of available sequences is sufficiently large that many independent occurrences of each neutral mutation are observed.
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Affiliation(s)
- Jesse D Bloom
- Basic Sciences and Computational Biology, Fred Hutchinson Cancer Center, 1100 Fairview Ave N, Seattle, WA 98109, USA
- Department of Genome Sciences, University of Washington, 3720 15th Ave NE, Seattle, WA 98195, USA
- Howard Hughes Medical Institute, 1100 Fairview Ave N, Seattle, WA 98109, USA
| | - Richard A Neher
- Biozentrum, University of Basel, Spitalstrasse 41, Basel 4056, Switzerland
- Swiss Institute of Bioinformatics, Lausanne 1015, Switzerl
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29
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Rigby CV, Sabsay KR, Bisht K, Eggink D, Jalal H, te Velthuis AJW. Evolution of transient RNA structure-RNA polymerase interactions in respiratory RNA virus genomes. Virus Evol 2023; 9:vead056. [PMID: 37692892 PMCID: PMC10492445 DOI: 10.1093/ve/vead056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/02/2023] [Accepted: 08/24/2023] [Indexed: 09/12/2023] Open
Abstract
RNA viruses are important human pathogens that cause seasonal epidemics and occasional pandemics. Examples are influenza A viruses (IAV) and coronaviruses (CoV). When emerging IAV and CoV spill over to humans, they adapt to evade immune responses and optimize their replication and spread in human cells. In IAV, adaptation occurs in all viral proteins, including the viral ribonucleoprotein (RNP) complex. RNPs consist of a copy of the viral RNA polymerase, a double-helical coil of nucleoprotein, and one of the eight segments of the IAV RNA genome. The RNA segments and their transcripts are partially structured to coordinate the packaging of the viral genome and modulate viral mRNA translation. In addition, RNA structures can affect the efficiency of viral RNA synthesis and the activation of host innate immune response. Here, we investigated if RNA structures that modulate IAV replication processivity, so-called template loops (t-loops), vary during the adaptation of pandemic and emerging IAV to humans. Using cell culture-based replication assays and in silico sequence analyses, we find that the sensitivity of the IAV H3N2 RNA polymerase to t-loops increased between isolates from 1968 and 2017, whereas the total free energy of t-loops in the IAV H3N2 genome was reduced. This reduction is particularly prominent in the PB1 gene. In H1N1 IAV, we find two separate reductions in t-loop free energy, one following the 1918 pandemic and one following the 2009 pandemic. No destabilization of t-loops is observed in the influenza B virus genome, whereas analysis of SARS-CoV-2 isolates reveals destabilization of viral RNA structures. Overall, we propose that a loss of free energy in the RNA genome of emerging respiratory RNA viruses may contribute to the adaption of these viruses to the human population.
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Affiliation(s)
- Charlotte V Rigby
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
- Department of Pathology, Addenbrooke’s Hospital, University of Cambridge, Hills Road, Cambridge CB2 2QQ, UK
- Addenbrooke’s Hospital, Public Health England, Hills Road, Cambridge CB2 2QQ, UK
| | - Kimberly R Sabsay
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
- Carl Icahn Laboratory, Lewis-Sigler Institute, Princeton University, South Drive, Princeton, NJ 08544, USA
| | - Karishma Bisht
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Dirk Eggink
- Department of Medical Microbiology, Amsterdam UMC, Meibergdreef 9, Amsterdam 1105 AZ, The Netherlands
| | - Hamid Jalal
- Addenbrooke’s Hospital, Public Health England, Hills Road, Cambridge CB2 2QQ, UK
| | - Aartjan J W te Velthuis
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Washington Road, Princeton, NJ 08544, USA
- Center for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Antonie van Leeuwenhoeklaan 9, Bilthoven 3721 MA, the Netherlands
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30
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Salukhe I, Choi R, Van Voorhis W, Barrett L, Hyde J. Regulation of coronavirus nsp15 cleavage specificity by RNA structure. PLoS One 2023; 18:e0290675. [PMID: 37616296 PMCID: PMC10449227 DOI: 10.1371/journal.pone.0290675] [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: 05/17/2023] [Accepted: 08/13/2023] [Indexed: 08/26/2023] Open
Abstract
SARS-CoV-2, the etiologic agent of the COVID-19 pandemic, has had an enduring impact on global public health. However, SARS-CoV-2 is only one of multiple pathogenic human coronaviruses (CoVs) to have emerged since the turn of the century. CoVs encode for several nonstructural proteins (nsps) that are essential for viral replication and pathogenesis. Among them is nsp15, a uridine-specific viral endonuclease that is important in evading the host immune response and promoting viral replication. Despite the established endonuclease function of nsp15, little is known about other determinants of its cleavage specificity. In this study we investigate the role of RNA secondary structure in SARS-CoV-2 nsp15 endonuclease activity. Using a series of in vitro endonuclease assays, we observed that thermodynamically stable RNA structures were protected from nsp15 cleavage relative to RNAs lacking stable structure. We leveraged the s2m RNA from the SARS-CoV-1 3'UTR as a model for our structural studies as it adopts a well-defined structure with several uridines, two of which are unpaired and thus highly probable targets for nsp15 cleavage. We found that SARS-CoV-2 nsp15 specifically cleaves s2m at the unpaired uridine within the GNRNA pentaloop of the RNA. Further investigation revealed that the position of uridine within the pentaloop also impacted nsp15 cleavage efficiency suggesting that positioning within the pentaloop is necessary for optimal presentation of the scissile uridine and alignment within the nsp15 catalytic pocket. Our findings indicate that RNA secondary structure is an important determinant of nsp15 cleavage and provides insight into the molecular mechanisms of RNA recognition by nsp15.
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Affiliation(s)
- Indraneel Salukhe
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States of America
| | - Ryan Choi
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington School of Medicine, Seattle, WA, United States of America
| | - Wesley Van Voorhis
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington School of Medicine, Seattle, WA, United States of America
| | - Lynn Barrett
- Division of Allergy and Infectious Diseases, Department of Medicine, Center for Emerging and Reemerging Infectious Diseases (CERID), University of Washington School of Medicine, Seattle, WA, United States of America
| | - Jennifer Hyde
- Department of Microbiology, University of Washington School of Medicine, Seattle, WA, United States of America
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31
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Wang W, Liu F, Ugalde MV, Pyle AM. A compact regulatory RNA element in mouse Hsp70 mRNA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.22.529618. [PMID: 36865185 PMCID: PMC9980084 DOI: 10.1101/2023.02.22.529618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Hsp70 performs molecular chaperone functions by assisting in folding newly synthesized or misfolded proteins, thereby counteracting various cell stresses and preventing multiple diseases including neurodegenerative disorders and cancer. It is well established that Hsp70 upregulation during post-heat shock stimulus is mediated by cap-dependent translation. However, the molecular mechanisms of Hsp70 expression during heat shock stimulus remains elusive, even though the 5' end of Hsp70 mRNA may form a compact structure to positively regulate protein expression in the mode of cap-independent translation. The minimal truncation which can fold to a compact structure was mapped and its secondary structure was characterized by chemical probing. The predicted model revealed a highly compact structure with multiple stems. Including the stem where the canonical start codon is located, several stems were identified to be vital for RNA folding, thereby providing solid structural basis for future investigations on the function of this RNA structure on Hsp70 translation during heat shock.
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32
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Rigby C, Sabsay K, Bisht K, Eggink D, Jalal H, te Velthuis AJ. Evolution of transient RNA structure-RNA polymerase interactions in respiratory RNA virus genomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542331. [PMID: 37292879 PMCID: PMC10245964 DOI: 10.1101/2023.05.25.542331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
RNA viruses are important human pathogens that cause seasonal epidemics and occasional pandemics. Examples are influenza A viruses (IAV) and coronaviruses (CoV). When emerging IAV and CoV spill over to humans, they adapt to evade immune responses and optimize their replication and spread in human cells. In IAV, adaptation occurs in all viral proteins, including the viral ribonucleoprotein (RNP) complex. RNPs consists of a copy of the viral RNA polymerase, a double-helical coil of nucleoprotein, and one of the eight segments of the IAV RNA genome. The RNA segments and their transcripts are partially structured to coordinate the packaging of the viral genome and modulate viral mRNA translation. In addition, RNA structures can affect the efficiency of viral RNA synthesis and the activation of host innate immune response. Here, we investigated if RNA structures that modulate IAV replication processivity, so called template loops (t-loops), vary during the adaptation of pandemic and emerging IAV to humans. Using cell culture-based replication assays and in silico sequence analyses, we find that the sensitivity of the IAV H3N2 RNA polymerase to t-loops increased between isolates from 1968 and 2017, whereas the total free energy of t-loops in the IAV H3N2 genome was reduced. This reduction is particularly prominent in the PB1 gene. In H1N1 IAV, we find two separate reductions in t-loop free energy, one following the 1918 pandemic and one following the 2009 pandemic. No destabilization of t-loops is observed in the IBV genome, whereas analysis of SARS-CoV-2 isolates reveals destabilization of viral RNA structures. Overall, we propose that a loss of free energy in the RNA genome of emerging respiratory RNA viruses may contribute to the adaption of these viruses to the human population.
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Affiliation(s)
- Charlotte Rigby
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, 08544 New Jersey, United States
- University of Cambridge, Department of Pathology, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
- Public Health England, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
| | - Kimberly Sabsay
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, 08544 New Jersey, United States
- Sigler Institute, Princeton University, Princeton, NJ 08544, United States
| | - Karishma Bisht
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, 08544 New Jersey, United States
| | - Dirk Eggink
- Department of Medical Microbiology, Amsterdam UMC, Amsterdam, The Netherlands
- Center for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands
| | - Hamid Jalal
- Public Health England, Addenbrooke’s Hospital, Cambridge CB2 2QQ, United Kingdom
| | - Aartjan J.W. te Velthuis
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, 08544 New Jersey, United States
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33
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Shi B, An K, Wang Y, Fei Y, Guo C, Cliff Zhang Q, Yang YG, Tian X, Kan Q. RNA Structural Dynamics Modulate EGFR-TKI Resistance Through Controlling YRDC Translation in NSCLC Cells. GENOMICS, PROTEOMICS & BIOINFORMATICS 2023; 21:850-865. [PMID: 36435452 PMCID: PMC10787121 DOI: 10.1016/j.gpb.2022.10.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 10/25/2022] [Accepted: 10/31/2022] [Indexed: 11/27/2022]
Abstract
Epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) positively affect the initial control of non-small cell lung cancer (NSCLC). Rapidly acquired resistance to EGFR-TKIs is a major hurdle in successful treatment. However, the mechanisms that control the resistance of EGFR-TKIs remain largely unknown. RNA structures have widespread and crucial functions in many biological regulations; however, the functions of RNA structures in regulating cancer drug resistance remain unclear. Here, the psoralen analysis of RNA interactions and structures (PARIS) method is used to establish the higher-order RNA structure maps of EGFR-TKIs-resistant and -sensitive cells of NSCLC. Our results show that RNA structural regions are enriched in untranslated regions (UTRs) and correlate with translation efficiency (TE). Moreover, yrdC N6-threonylcarbamoyltransferase domain containing (YRDC) promotes resistance to EGFR-TKIs. RNA structure formation in YRDC 3' UTR suppresses embryonic lethal abnormal vision-like 1 (ELAVL1) binding, leading to EGFR-TKI sensitivity by impairing YRDC translation. A potential therapeutic strategy for cancer treatment is provided using antisense oligonucleotide (ASO) to perturb the interaction between RNA and protein. Our study reveals an unprecedented mechanism through which the RNA structure switch modulates EGFR-TKI resistance by controlling YRDC mRNA translation in an ELAVL1-dependent manner.
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Affiliation(s)
- Boyang Shi
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, Zhengzhou University, Zhengzhou 450052, China; Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
| | - Ke An
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, Zhengzhou University, Zhengzhou 450052, China; Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
| | - Yueqin Wang
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, Zhengzhou University, Zhengzhou 450052, China
| | - Yuhan Fei
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Caixia Guo
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China
| | - Qiangfeng Cliff Zhang
- MOE Key Laboratory of Bioinformatics, Center for Synthetic and Systems Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Yun-Gui Yang
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences and China National Center for Bioinformation, Beijing 100101, China.
| | - Xin Tian
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China; Henan Key Laboratory of Precision Clinical Pharmacy, Zhengzhou University, Zhengzhou 450052, China.
| | - Quancheng Kan
- Henan Key Laboratory of Precision Clinical Pharmacy, Zhengzhou University, Zhengzhou 450052, China.
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Guo LT, Pyle AM. End-to-end RT-PCR of long RNA and highly structured RNA. Methods Enzymol 2023; 691:3-15. [PMID: 37914451 DOI: 10.1016/bs.mie.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
RNA molecules play important roles in numerous normal cellular processes and disease states, from protein coding to gene regulation. RT-PCR, applying the power of polymerase chain reaction (PCR) to RNA by coupling reverse transcription with PCR, is one of the most important techniques to characterize RNA transcripts and monitor gene expression. The ability to analyze full-length RNA transcripts and detect their expression is critical to decipher their biological functions. However, due to the low processivity of retroviral reverse transcriptases (RTs), we can only monitor a small fraction of long RNA transcripts, especially those containing stable secondary and tertiary structures. The full-length sequences can only be deduced by computational analysis, which is often misleading. Group II intron-encoded RTs are a new type of RT enzymes. They have evolved specialized structural elements that unwind template structures and maintain close contact with the RNA template. Therefore, group II intron-encoded RTs are more processive than the retroviral RTs. The discovery, optimization and deployment of processive group II intron RTs provide us the opportunity to analyze RNA transcripts with single molecule resolution. MarathonRT, the most processive group II intron RT, has been extensively optimized for processive reverse transcription. In this chapter, we use MarathonRT to deliver a general protocol for long amplicon generation by RT-PCR, and also provide guidance for troubleshooting and further optimization.
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Affiliation(s)
- Li-Tao Guo
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States
| | - Anna Marie Pyle
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT, United States; Department of Chemistry, Yale University, New Haven, CT, United States; Howard Hughes Medical Institute, Chevy Chase, MD, United States.
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35
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Jiang H, Joshi A, Gan T, Janowski AB, Fujii C, Bricker TL, Darling TL, Harastani HH, Seehra K, Chen H, Tahan S, Jung A, Febles B, Blatter JA, Handley SA, Parikh BA, Wang D, Boon ACM. The Highly Conserved Stem-Loop II Motif Is Dispensable for SARS-CoV-2. J Virol 2023; 97:e0063523. [PMID: 37223945 PMCID: PMC10308922 DOI: 10.1128/jvi.00635-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 05/01/2023] [Indexed: 05/25/2023] Open
Abstract
The stem-loop II motif (s2m) is an RNA structural element that is found in the 3' untranslated region (UTR) of many RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Though the motif was discovered over 25 years ago, its functional significance is unknown. In order to understand the importance of s2m, we created viruses with deletions or mutations of the s2m by reverse genetics and also evaluated a clinical isolate harboring a unique s2m deletion. Deletion or mutation of the s2m had no effect on growth in vitro or on growth and viral fitness in Syrian hamsters in vivo. We also compared the secondary structure of the 3' UTR of wild-type and s2m deletion viruses using selective 2'-hydroxyl acylation analyzed by primer extension and mutational profiling (SHAPE-MaP) and dimethyl sulfate mutational profiling and sequencing (DMS-MaPseq). These experiments demonstrate that the s2m forms an independent structure and that its deletion does not alter the overall remaining 3'-UTR RNA structure. Together, these findings suggest that s2m is dispensable for SARS-CoV-2. IMPORTANCE RNA viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), contain functional structures to support virus replication, translation, and evasion of the host antiviral immune response. The 3' untranslated region of early isolates of SARS-CoV-2 contained a stem-loop II motif (s2m), which is an RNA structural element that is found in many RNA viruses. This motif was discovered over 25 years ago, but its functional significance is unknown. We created SARS-CoV-2 with deletions or mutations of the s2m and determined the effect of these changes on viral growth in tissue culture and in rodent models of infection. Deletion or mutation of the s2m element had no effect on growth in vitro or on growth and viral fitness in Syrian hamsters in vivo. We also observed no impact of the deletion on other known RNA structures in the same region of the genome. These experiments demonstrate that s2m is dispensable for SARS-CoV-2.
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Affiliation(s)
- Hongbing Jiang
- School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, China
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Astha Joshi
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tianyu Gan
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Andrew B. Janowski
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Chika Fujii
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Traci L. Bricker
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tamarand L. Darling
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Houda H. Harastani
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kuljeet Seehra
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hongwei Chen
- School of Public Health (Shenzhen), Sun Yat-sen University, Shenzhen, China
| | - Stephen Tahan
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Ana Jung
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Binita Febles
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Joshua A. Blatter
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Scott A. Handley
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Bijal A. Parikh
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - David Wang
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Adrianus C. M. Boon
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
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36
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Zhang D, Qiao L, Lei X, Dong X, Tong Y, Wang J, Wang Z, Zhou R. Mutagenesis and structural studies reveal the basis for the specific binding of SARS-CoV-2 SL3 RNA element with human TIA1 protein. Nat Commun 2023; 14:3715. [PMID: 37349329 PMCID: PMC10287707 DOI: 10.1038/s41467-023-39410-8] [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: 10/04/2022] [Accepted: 06/12/2023] [Indexed: 06/24/2023] Open
Abstract
Viral RNA-host protein interactions are indispensable during RNA virus transcription and replication, but their detailed structural and dynamical features remain largely elusive. Here, we characterize the binding interface for the SARS-CoV-2 stem-loop 3 (SL3) cis-acting element to human TIA1 protein with a combined theoretical and experimental approaches. The highly structured SARS-CoV-2 SL3 has a high binding affinity to TIA1 protein, in which the aromatic stacking, hydrogen bonds, and hydrophobic interactions collectively direct this specific binding. Further mutagenesis studies validate our proposed 3D binding model and reveal two SL3 variants have enhanced binding affinities to TIA1. And disruptions of the identified RNA-protein interactions with designed antisense oligonucleotides dramatically reduce SARS-CoV-2 infection in cells. Finally, TIA1 protein could interact with conserved SL3 RNA elements within other betacoronavirus lineages. These findings open an avenue to explore the viral RNA-host protein interactions and provide a pioneering structural basis for RNA-targeting antiviral drug design.
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Affiliation(s)
- Dong Zhang
- Institute of Quantitative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Lulu Qiao
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China
| | - Xiaobo Lei
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Xiaojing Dong
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China
| | - Yunguang Tong
- College of Life Sciences, China Jiliang University, Hangzhou, Zhejiang, 310018, China
- Department of Pharmacy, China Jiliang University, Hangzhou, Zhejiang, 310018, China
| | - Jianwei Wang
- NHC Key Laboratory of Systems Biology of Pathogens and Christophe Mérieux Laboratory, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100730, China.
| | - Zhiye Wang
- State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
- The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
| | - Ruhong Zhou
- Institute of Quantitative Biology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
- The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang, 310058, China.
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37
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Wildi N, Seuberlich T. The Roles of the 5' and 3' Untranslated Regions in Human Astrovirus Replication. Viruses 2023; 15:1402. [PMID: 37376701 DOI: 10.3390/v15061402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/19/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023] Open
Abstract
Astroviruses are small nonenveloped single-stranded RNA viruses with a positive sense genome. They are known to cause gastrointestinal disease in a broad spectrum of species. Although astroviruses are distributed worldwide, a gap in knowledge of their biology and disease pathogenesis persists. Many positive-sense single-stranded RNA viruses show conserved and functionally important structures in their 5' and 3' untranslated regions (UTRs). However, not much is known about the role of the 5' and 3' UTRs in the viral replication of HAstV-1. We analyzed the UTRs of HAstV-1 for secondary RNA structures and mutated them, resulting in partial or total UTR deletion. We used a reverse genetic system to study the production of infectious viral particles and to quantify protein expression in the 5' and 3' UTR mutants, and we established an HAstV-1 replicon system containing two reporter cassettes in open reading frames 1a and 2, respectively. Our data show that 3' UTR deletions almost completely abolished viral protein expression and that 5' UTR deletions led to a reduction in infectious virus particles in infection experiments. This indicates that the presence of the UTRs is essential for the life cycle of HAstV-1 and opens avenues for further research.
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Affiliation(s)
- Nicole Wildi
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Torsten Seuberlich
- Division of Neurological Sciences, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
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38
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Hedaya OM, Subbaiah KCV, Jiang F, Xie LH, Wu J, Khor E, Zhu M, Mathews DH, Proschel C, Yao P. Secondary structures that regulate mRNA translation provide insights for ASO-mediated modulation of cardiac hypertrophy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.15.545153. [PMID: 37397986 PMCID: PMC10312771 DOI: 10.1101/2023.06.15.545153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Translation of upstream open reading frames (uORFs) typically abrogates translation of main (m)ORFs. The molecular mechanism of uORF regulation in cells is not well understood. Here, we identified a double-stranded RNA (dsRNA) structure residing within the GATA4 uORF that augments uORF translation and inhibits mORF translation. Antisense oligonucleotides (ASOs) that disrupt this dsRNA structure promote mORF translation, while ASOs that base-pair immediately downstream (i.e., forming a bimolecular double-stranded region) of either the uORF or mORF start codon enhance uORF or mORF translation, respectively. Human cardiomyocytes and mice treated with a uORF-enhancing ASO showed reduced cardiac GATA4 protein levels and increased resistance to cardiomyocyte hypertrophy. We further show the general utility of uORF-dsRNA- or mORF- targeting ASO to regulate mORF translation for other mRNAs. Our work demonstrates a regulatory paradigm that controls translational efficiency and a useful strategy to alter protein expression and cellular phenotypes by targeting or generating dsRNA downstream of a uORF or mORF start codon. Bullet points for discoveries dsRNA within GATA4 uORF activates uORF translation and inhibits mORF translation. ASOs that target the dsRNA can either inhibit or enhance GATA4 mORF translation. ASOs can be used to impede hypertrophy in human cardiomyocytes and mouse hearts.uORF- and mORF-targeting ASOs can be used to control translation of multiple mRNAs.
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Affiliation(s)
- Omar M. Hedaya
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Kadiam C. Venkata Subbaiah
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Feng Jiang
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Li Huitong Xie
- Department of Biomedical Genetics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Jiangbin Wu
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - EngSoon Khor
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Mingyi Zhu
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- The Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - David H. Mathews
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- The Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- The Center for Biomedical Informatics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Chris Proschel
- Department of Biomedical Genetics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
| | - Peng Yao
- Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- Department of Biochemistry & Biophysics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- The Center for RNA Biology, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
- The Center for Biomedical Informatics, University of Rochester School of Medicine & Dentistry, Rochester, New York 14642
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39
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Khan D, Terenzi F, Liu G, Ghosh PK, Ye F, Nguyen K, China A, Ramachandiran I, Chakraborty S, Stefan J, Khan K, Vasu K, Dong F, Willard B, Karn J, Gack MU, Fox PL. A viral pan-end RNA element and host complex define a SARS-CoV-2 regulon. Nat Commun 2023; 14:3385. [PMID: 37296097 PMCID: PMC10250186 DOI: 10.1038/s41467-023-39091-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 05/25/2023] [Indexed: 06/12/2023] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, generates multiple protein-coding, subgenomic RNAs (sgRNAs) from a longer genomic RNA, all bearing identical termini with poorly understood roles in regulating viral gene expression. Insulin and interferon-gamma, two host-derived, stress-related agents, and virus spike protein, induce binding of glutamyl-prolyl-tRNA synthetase (EPRS1), within an unconventional, tetra-aminoacyl-tRNA synthetase complex, to the sgRNA 3'-end thereby enhancing sgRNA expression. We identify an EPRS1-binding sarbecoviral pan-end activating RNA (SPEAR) element in the 3'-end of viral RNAs driving agonist-induction. Translation of another co-terminal 3'-end feature, ORF10, is necessary for SPEAR-mediated induction, independent of Orf10 protein expression. The SPEAR element enhances viral programmed ribosomal frameshifting, thereby expanding its functionality. By co-opting noncanonical activities of a family of essential host proteins, the virus establishes a post-transcriptional regulon stimulating global viral RNA translation. A SPEAR-targeting strategy markedly reduces SARS-CoV-2 titer, suggesting a pan-sarbecoviral therapeutic modality.
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Affiliation(s)
- Debjit Khan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Fulvia Terenzi
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - GuanQun Liu
- Florida Research and Innovation Center, Cleveland Clinic Foundation, Port St. Lucie, FL, 34987, USA
| | - Prabar K Ghosh
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Fengchun Ye
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Kien Nguyen
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Arnab China
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Iyappan Ramachandiran
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Shruti Chakraborty
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Jennifer Stefan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Krishnendu Khan
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Kommireddy Vasu
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Franklin Dong
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Belinda Willard
- Lerner Research Institute Proteomics and Metabolomics Core, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA
| | - Jonathan Karn
- Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Michaela U Gack
- Florida Research and Innovation Center, Cleveland Clinic Foundation, Port St. Lucie, FL, 34987, USA
| | - Paul L Fox
- Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH, 44195, USA.
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40
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Patel S, Sexton AN, Strine MS, Wilen CB, Simon MD, Pyle AM. Systematic detection of tertiary structural modules in large RNAs and RNP interfaces by Tb-seq. Nat Commun 2023; 14:3426. [PMID: 37296103 PMCID: PMC10255950 DOI: 10.1038/s41467-023-38623-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 05/09/2023] [Indexed: 06/12/2023] Open
Abstract
Compact RNA structural motifs control many aspects of gene expression, but we lack methods for finding these structures in the vast expanse of multi-kilobase RNAs. To adopt specific 3-D shapes, many RNA modules must compress their RNA backbones together, bringing negatively charged phosphates into close proximity. This is often accomplished by recruiting multivalent cations (usually Mg2+), which stabilize these sites and neutralize regions of local negative charge. Coordinated lanthanide ions, such as terbium (III) (Tb3+), can also be recruited to these sites, where they induce efficient RNA cleavage, thereby revealing compact RNA 3-D modules. Until now, Tb3+ cleavage sites were monitored via low-throughput biochemical methods only applicable to small RNAs. Here we present Tb-seq, a high-throughput sequencing method for detecting compact tertiary structures in large RNAs. Tb-seq detects sharp backbone turns found in RNA tertiary structures and RNP interfaces, providing a way to scan transcriptomes for stable structural modules and potential riboregulatory motifs.
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Affiliation(s)
- Shivali Patel
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Alec N Sexton
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Madison S Strine
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Craig B Wilen
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Matthew D Simon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Chemical Biology Institute, Yale University, West Haven, CT, USA
| | - Anna Marie Pyle
- Howard Hughes Medical Institute, Chevy Chase, MD, USA.
- Department of Chemistry, Yale University, New Haven, CT, USA.
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT, USA.
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41
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Yang M, Olatunji FP, Rhodes C, Balaratnam S, Dunne-Dombrink K, Seshadri S, Liang X, Jones CP, Le Grice SFJ, Ferré-D’Amaré AR, Schneekloth JS. Discovery of Small Molecules Targeting the Frameshifting Element RNA in SARS-CoV-2 Viral Genome. ACS Med Chem Lett 2023; 14:757-765. [PMID: 37312842 PMCID: PMC10258829 DOI: 10.1021/acsmedchemlett.3c00051] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/02/2023] [Indexed: 06/15/2023] Open
Abstract
Targeting structured RNA elements in the SARS-CoV-2 viral genome with small molecules is an attractive strategy for pharmacological control over viral replication. In this work, we report the discovery of small molecules that target the frameshifting element (FSE) in the SARS-CoV-2 RNA genome using high-throughput small-molecule microarray (SMM) screening. A new class of aminoquinazoline ligands for the SARS-CoV-2 FSE are synthesized and characterized using multiple orthogonal biophysical assays and structure-activity relationship (SAR) studies. This work reveals compounds with mid-micromolar binding affinity (KD = 60 ± 6 μM) to the FSE RNA and supports a binding mode distinct from previously reported FSE binders MTDB and merafloxacin. In addition, compounds are active in in vitro dual-luciferase and in-cell dual-fluorescent-reporter frameshifting assays, highlighting the promise of targeting structured elements of RNAs with druglike compounds to alter expression of viral proteins.
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Affiliation(s)
- Mo Yang
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Feyisola P. Olatunji
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Curran Rhodes
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Sumirtha Balaratnam
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Kara Dunne-Dombrink
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Srinath Seshadri
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Xiao Liang
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
| | - Christopher P. Jones
- Biochemistry
and Biophysics Center, National Heart, Lung,
and Blood Institute, Bethesda, Maryland 20892, United States
| | - Stuart F. J. Le Grice
- Cancer
Innovation Laboratory, Center for Cancer Research, National Cancer Institute, Frederick Maryland 21702-1201, United States
| | - Adrian R. Ferré-D’Amaré
- Biochemistry
and Biophysics Center, National Heart, Lung,
and Blood Institute, Bethesda, Maryland 20892, United States
| | - John S. Schneekloth
- Chemical
Biology Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
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42
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Korn SM, Dhamotharan K, Jeffries CM, Schlundt A. The preference signature of the SARS-CoV-2 Nucleocapsid NTD for its 5'-genomic RNA elements. Nat Commun 2023; 14:3331. [PMID: 37286558 DOI: 10.1038/s41467-023-38882-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/17/2023] [Indexed: 06/09/2023] Open
Abstract
The nucleocapsid protein (N) of SARS-CoV-2 plays a pivotal role during the viral life cycle. It is involved in RNA transcription and accounts for packaging of the large genome into virus particles. N manages the enigmatic balance of bulk RNA-coating versus precise RNA-binding to designated cis-regulatory elements. Numerous studies report the involvement of its disordered segments in non-selective RNA-recognition, but how N organizes the inevitable recognition of specific motifs remains unanswered. We here use NMR spectroscopy to systematically analyze the interactions of N's N-terminal RNA-binding domain (NTD) with individual cis RNA elements clustering in the SARS-CoV-2 regulatory 5'-genomic end. Supported by broad solution-based biophysical data, we unravel the NTD RNA-binding preferences in the natural genome context. We show that the domain's flexible regions read the intrinsic signature of preferred RNA elements for selective and stable complex formation within the large pool of available motifs.
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Affiliation(s)
- Sophie Marianne Korn
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt/M., Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany
| | - Karthikeyan Dhamotharan
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt/M., Germany
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany
| | - Cy M Jeffries
- European Molecular Biology Laboratory (EMBL) Hamburg Site, c/o Deutsches Elektronen-Synchrotron, Notkestr. 85, 22607, Hamburg, Germany
| | - Andreas Schlundt
- Institute for Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438, Frankfurt/M., Germany.
- Center for Biomolecular Magnetic Resonance (BMRZ), Goethe University Frankfurt, Max-von-Laue-Str. 7, 60438, Frankfurt/M., Germany.
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Bloom JD, Neher RA. Fitness effects of mutations to SARS-CoV-2 proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.30.526314. [PMID: 36778462 PMCID: PMC9915511 DOI: 10.1101/2023.01.30.526314] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Knowledge of the fitness effects of mutations to SARS-CoV-2 can inform assessment of new variants, design of therapeutics resistant to escape, and understanding of the functions of viral proteins. However, experimentally measuring effects of mutations is challenging: we lack tractable lab assays for many SARS-CoV-2 proteins, and comprehensive deep mutational scanning has been applied to only two SARS-CoV-2 proteins. Here we develop an approach that leverages millions of publicly available SARS-CoV-2 sequences to estimate effects of mutations. We first calculate how many independent occurrences of each mutation are expected to be observed along the SARS-CoV-2 phylogeny in the absence of selection. We then compare these expected observations to the actual observations to estimate the effect of each mutation. These estimates correlate well with deep mutational scanning measurements. For most genes, synonymous mutations are nearly neutral, stop-codon mutations are deleterious, and amino-acid mutations have a range of effects. However, some viral accessory proteins are under little to no selection. We provide interactive visualizations of effects of mutations to all SARS-CoV-2 proteins (https://jbloomlab.github.io/SARS2-mut-fitness/). The framework we describe is applicable to any virus for which the number of available sequences is sufficiently large that many independent occurrences of each neutral mutation are observed.
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Affiliation(s)
- Jesse D. Bloom
- Basic Sciences and Computational Biology, Fred Hutchinson Cancer Center
- Department of Genome Sciences, University of Washington
- Howard Hughes Medical Institute
| | - Richard A. Neher
- Biozentrum, University of Basel
- Swiss Institute of Bioinformatics
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44
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Ryan C, Rahman MM, Kumar V, Rozners E. Triplex-Forming Peptide Nucleic Acid Controls Dynamic Conformations of RNA Bulges. J Am Chem Soc 2023; 145:10497-10504. [PMID: 37155726 PMCID: PMC10198159 DOI: 10.1021/jacs.2c12488] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Indexed: 05/10/2023]
Abstract
RNA folding is driven by the formation of double-helical segments interspaced by loops of unpaired nucleotides. Among the latter, bulges formed by one or several unpaired nucleotides are one of the most common structural motifs that play an important role in stabilizing RNA-RNA, RNA-protein, and RNA-small molecule interactions. Single-nucleotide bulges can fold in alternative structures where the unpaired nucleobase is either looped-out (flexible) in a solvent or stacked-in (intercalated) between the base pairs. In the present study, we discovered that triplex-forming peptide nucleic acids (PNAs) had unusually high affinity for single-purine-nucleotide bulges in double-helical RNA. Depending on the PNA's sequence, the triplex formation shifted the equilibrium between looped-out and stacked-in conformations. The ability to control the dynamic equilibria of RNA's structure will be an important tool for studying structure-function relationships in RNA biology and may have potential in novel therapeutic approaches targeting disease-related RNAs.
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Affiliation(s)
- Christopher
A. Ryan
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
| | - Md Motiar Rahman
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
| | - Vipin Kumar
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
| | - Eriks Rozners
- Department of Chemistry, The State
University of New York, Binghamton University, Binghamton, New York 13902, United States
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45
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Mirska B, Woźniak T, Lorent D, Ruszkowska A, Peterson JM, Moss WN, Mathews DH, Kierzek R, Kierzek E. In vivo secondary structural analysis of Influenza A virus genomic RNA. Cell Mol Life Sci 2023; 80:136. [PMID: 37131079 PMCID: PMC10153785 DOI: 10.1007/s00018-023-04764-1] [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: 10/28/2022] [Revised: 03/19/2023] [Accepted: 03/19/2023] [Indexed: 05/04/2023]
Abstract
Influenza A virus (IAV) is a respiratory virus that causes epidemics and pandemics. Knowledge of IAV RNA secondary structure in vivo is crucial for a better understanding of virus biology. Moreover, it is a fundament for the development of new RNA-targeting antivirals. Chemical RNA mapping using selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE) coupled with Mutational Profiling (MaP) allows for the thorough examination of secondary structures in low-abundance RNAs in their biological context. So far, the method has been used for analyzing the RNA secondary structures of several viruses including SARS-CoV-2 in virio and in cellulo. Here, we used SHAPE-MaP and dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) for genome-wide secondary structure analysis of viral RNA (vRNA) of the pandemic influenza A/California/04/2009 (H1N1) strain in both in virio and in cellulo environments. Experimental data allowed the prediction of the secondary structures of all eight vRNA segments in virio and, for the first time, the structures of vRNA5, 7, and 8 in cellulo. We conducted a comprehensive structural analysis of the proposed vRNA structures to reveal the motifs predicted with the highest accuracy. We also performed a base-pairs conservation analysis of the predicted vRNA structures and revealed many highly conserved vRNA motifs among the IAVs. The structural motifs presented herein are potential candidates for new IAV antiviral strategies.
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Affiliation(s)
- Barbara Mirska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Tomasz Woźniak
- Institute of Human Genetics, Polish Academy of Sciences, Strzeszynska 32, 60-479, Poznan, Poland
| | - Dagny Lorent
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Agnieszka Ruszkowska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Jake M Peterson
- Roy J. Carver Department of Biophysics, Biochemistry and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Walter N Moss
- Roy J. Carver Department of Biophysics, Biochemistry and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - David H Mathews
- Department of Biochemistry & Biophysics and Center for RNA Biology, School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Box 712, Rochester, NY, 14642, USA
| | - Ryszard Kierzek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland
| | - Elzbieta Kierzek
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704, Poznan, Poland.
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46
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Chiara M, Horner DS, Ferrandi E, Gissi C, Pesole G. HaploCoV: unsupervised classification and rapid detection of novel emerging variants of SARS-CoV-2. Commun Biol 2023; 6:443. [PMID: 37087497 PMCID: PMC10122080 DOI: 10.1038/s42003-023-04784-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 03/30/2023] [Indexed: 04/24/2023] Open
Abstract
Accurate and timely monitoring of the evolution of SARS-CoV-2 is crucial for identifying and tracking potentially more transmissible/virulent viral variants, and implement mitigation strategies to limit their spread. Here we introduce HaploCoV, a novel software framework that enables the exploration of SARS-CoV-2 genomic diversity through space and time, to identify novel emerging viral variants and prioritize variants of potential epidemiological interest in a rapid and unsupervised manner. HaploCoV can integrate with any classification/nomenclature and incorporates an effective scoring system for the prioritization of SARS-CoV-2 variants. By performing retrospective analyses of more than 11.5 M genome sequences we show that HaploCoV demonstrates high levels of accuracy and reproducibility and identifies the large majority of epidemiologically relevant viral variants - as flagged by international health authorities - automatically and with rapid turn-around times.Our results highlight the importance of the application of strategies based on the systematic analysis and integration of regional data for rapid identification of novel, emerging variants of SARS-CoV-2. We believe that the approach outlined in this study will contribute to relevant advances to current and future genomic surveillance methods.
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Affiliation(s)
- Matteo Chiara
- Department of Biosciences, University of Milan, Milan, Italy.
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Bari, Italy.
| | - David S Horner
- Department of Biosciences, University of Milan, Milan, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Erika Ferrandi
- Department of Biosciences, University of Milan, Milan, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Carmela Gissi
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Bari, Italy
- Department of Biosciences, Biotechnology and Environment, University of Bari "A. Moro", Bari, Italy
| | - Graziano Pesole
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies, Consiglio Nazionale delle Ricerche, Bari, Italy.
- Department of Biosciences, Biotechnology and Environment, University of Bari "A. Moro", Bari, Italy.
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47
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Forstmeier PC, Meyer MO, Bevilacqua PC. The Functional RNA Identification (FRID) Pipeline: Identification of Potential Pseudoknot-Containing RNA Elements as Therapeutic Targets for SARS-CoV-2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.03.535424. [PMID: 37066195 PMCID: PMC10103974 DOI: 10.1101/2023.04.03.535424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
The COVID-19 pandemic persists despite the development of effective vaccines. As such, it remains crucial to identify new targets for antiviral therapies. The causative virus of COVID-19, SARS-CoV-2, is a positive-sense RNA virus with RNA structures that could serve as therapeutic targets. One such RNA with established function is the frameshift stimulatory element (FSE), which promotes programmed ribosomal frameshifting. To accelerate identification of additional functional RNA elements, we introduce a novel computational approach termed the Functional RNA Identification (FRID) pipeline. The guiding principle of our pipeline, which uses established component programs as well as customized component programs, is that functional RNA elements have conserved secondary and pseudoknot structures that facilitate function. To assess the presence and conservation of putative functional RNA elements in SARS-CoV-2, we compared over 6,000 SARS-CoV-2 genomic isolates. We identified 22 functional RNA elements from the SARS-CoV-2 genome, 14 of which have conserved pseudoknots and serve as potential targets for small molecule or antisense oligonucleotide therapeutics. The FRID pipeline is general and can be applied to identify pseudoknotted RNAs for targeted therapeutics in genomes or transcriptomes from any virus or organism.
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48
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Bloom JD, Beichman AC, Neher RA, Harris K. Evolution of the SARS-CoV-2 Mutational Spectrum. Mol Biol Evol 2023; 40:msad085. [PMID: 37039557 PMCID: PMC10124870 DOI: 10.1093/molbev/msad085] [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: 11/19/2022] [Revised: 02/07/2023] [Accepted: 04/06/2023] [Indexed: 04/12/2023] Open
Abstract
SARS-CoV-2 evolves rapidly in part because of its high mutation rate. Here, we examine whether this mutational process itself has changed during viral evolution. To do this, we quantify the relative rates of different types of single-nucleotide mutations at 4-fold degenerate sites in the viral genome across millions of human SARS-CoV-2 sequences. We find clear shifts in the relative rates of several types of mutations during SARS-CoV-2 evolution. The most striking trend is a roughly 2-fold decrease in the relative rate of G→T mutations in Omicron versus early clades, as was recently noted by Ruis et al. (2022. Mutational spectra distinguish SARS-CoV-2 replication niches. bioRxiv, doi:10.1101/2022.09.27.509649). There is also a decrease in the relative rate of C→T mutations in Delta, and other subtle changes in the mutation spectrum along the phylogeny. We speculate that these changes in the mutation spectrum could arise from viral mutations that affect genome replication, packaging, and antagonization of host innate-immune factors, although environmental factors could also play a role. Interestingly, the mutation spectrum of Omicron is more similar than that of earlier SARS-CoV-2 clades to the spectrum that shaped the long-term evolution of sarbecoviruses. Overall, our work shows that the mutation process is itself a dynamic variable during SARS-CoV-2 evolution and suggests that human SARS-CoV-2 may be trending toward a mutation spectrum more similar to that of other animal sarbecoviruses.
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Affiliation(s)
- Jesse D Bloom
- Basic Sciences Division and Computational Biology Program, Fred Hutchinson Cancer Center, Seattle, WA
- Department of Genome Sciences, University of Washington, Seattle, WA
- Howard Hughes Medical Institute, Seattle, WA
| | | | - Richard A Neher
- Biozentrum, University of Basel, Basel, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Kelley Harris
- Department of Genome Sciences, University of Washington, Seattle, WA
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49
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Mackeown M, Kung YA, Davila-Calderon J, Ford WP, Luo L, Henry B, Li ML, Brewer G, Shih SR, Tolbert BS. The 5'UTR of HCoV-OC43 adopts a topologically constrained structure to intrinsically repress translation. J Biol Chem 2023; 299:103028. [PMID: 36805339 PMCID: PMC9930382 DOI: 10.1016/j.jbc.2023.103028] [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: 06/13/2022] [Revised: 02/10/2023] [Accepted: 02/12/2023] [Indexed: 02/17/2023] Open
Abstract
The emergence of SARS-CoV-2, which is responsible for the COVID-19 pandemic, has highlighted the need for rapid characterization of viral mechanisms associated with cellular pathogenesis. Viral UTRs represent conserved genomic elements that contribute to such mechanisms. Structural details of most CoV UTRs are not available, however. Experimental approaches are needed to allow for the facile generation of high-quality viral RNA tertiary structural models, which can facilitate comparative mechanistic efforts. By integrating experimental and computational techniques, we herein report the efficient characterization of conserved RNA structures within the 5'UTR of the HCoV-OC43 genome, a lab-tractable model coronavirus. We provide evidence that the 5'UTR folds into a structure with well-defined stem-loops (SLs) as determined by chemical probing and direct detection of hydrogen bonds by NMR. We combine experimental base-pair restraints with global structural information from SAXS to generate a 3D model that reveals that SL1-4 adopts a topologically constrained structure wherein SLs 3 and 4 coaxially stack. Coaxial stacking is mediated by short linker nucleotides and allows SLs 1 to 2 to sample different cojoint orientations by pivoting about the SL3,4 helical axis. To evaluate the functional relevance of the SL3,4 coaxial helix, we engineered luciferase reporter constructs harboring the HCoV-OC43 5'UTR with mutations designed to abrogate coaxial stacking. Our results reveal that the SL3,4 helix intrinsically represses translation efficiency since the destabilizing mutations correlate with increased luciferase expression relative to wildtype without affecting reporter mRNA levels, thus highlighting how the 5'UTR structure contributes to the viral mechanism.
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Affiliation(s)
- Matthew Mackeown
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yu-An Kung
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan City, Taiwan
| | | | - William P Ford
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio, USA
| | - Le Luo
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio, USA
| | - Barrington Henry
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio, USA
| | - Mei-Ling Li
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Gary Brewer
- Department of Biochemistry and Molecular Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, New Jersey, USA
| | - Shin-Ru Shih
- Research Center for Emerging Viral Infections, Chang Gung University, Taoyuan City, Taiwan
| | - Blanton S Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio, USA.
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50
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Keep S, Dowgier G, Lulla V, Britton P, Oade M, Freimanis G, Tennakoon C, Jonassen CM, Tengs T, Bickerton E. Deletion of the s2m RNA Structure in the Avian Coronavirus Infectious Bronchitis Virus and Human Astrovirus Results in Sequence Insertions. J Virol 2023; 97:e0003823. [PMID: 36779761 PMCID: PMC10062133 DOI: 10.1128/jvi.00038-23] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 01/25/2023] [Indexed: 02/14/2023] Open
Abstract
Coronaviruses infect a wide variety of host species, resulting in a range of diseases in both humans and animals. The coronavirus genome consists of a large positive-sense single-stranded molecule of RNA containing many RNA structures. One structure, denoted s2m and consisting of 41 nucleotides, is located within the 3' untranslated region (3' UTR) and is shared between some coronavirus species, including infectious bronchitis virus (IBV), severe acute respiratory syndrome coronavirus (SARS-CoV), and SARS-CoV-2, as well as other pathogens, including human astrovirus. Using a reverse genetic system to generate recombinant viruses, we investigated the requirement of the s2m structure in the replication of IBV, a globally distributed economically important Gammacoronavirus that infects poultry causing respiratory disease. Deletion of three nucleotides predicted to destabilize the canonical structure of the s2m or the deletion of the nucleotides corresponding to s2m impacted viral replication in vitro. In vitro passaging of the recombinant IBV with the s2m sequence deleted resulted in a 36-nucleotide insertion in place of the deletion, which was identified to be composed of a duplication of flanking sequences. A similar result was observed following serial passage of human astrovirus with a deleted s2m sequence. RNA modeling indicated that deletion of the nucleotides corresponding to the s2m impacted other RNA structures present in the IBV 3' UTR. Our results indicated for both IBV and human astrovirus a preference for nucleotide occupation in the genome location corresponding to the s2m, which is independent of the specific s2m sequence. IMPORTANCE Coronaviruses infect many species, including humans and animals, with substantial effects on livestock, particularly with respect to poultry. The coronavirus RNA genome consists of structural elements involved in viral replication whose roles are poorly understood. We investigated the requirement of the RNA structural element s2m in the replication of the Gammacoronavirus infectious bronchitis virus, an economically important viral pathogen of poultry. Using reverse genetics to generate recombinant IBVs with either a disrupted or deleted s2m, we showed that the s2m is not required for viral replication in cell culture; however, replication is decreased in tracheal tissue, suggesting a role for the s2m in the natural host. Passaging of these viruses as well as human astrovirus lacking the s2m sequence demonstrated a preference for nucleotide occupation, independent of the s2m sequence. RNA modeling suggested deletion of the s2m may negatively impact other essential RNA structures.
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Affiliation(s)
- Sarah Keep
- The Pirbright Institute, Woking, United Kingdom
| | | | - Valeria Lulla
- Department of Pathology, University of Cambridge, Addenbrookes Hospital, Cambridge, United Kingdom
| | | | - Michael Oade
- Department of Pathology, University of Cambridge, Addenbrookes Hospital, Cambridge, United Kingdom
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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