1
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Aruda J, Grote SL, Rouskin S. Untangling the pseudoknots of SARS-CoV-2: Insights into structural heterogeneity and plasticity. Curr Opin Struct Biol 2024; 88:102912. [PMID: 39168046 DOI: 10.1016/j.sbi.2024.102912] [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: 05/13/2024] [Revised: 07/26/2024] [Accepted: 07/29/2024] [Indexed: 08/23/2024]
Abstract
Since the onset of the COVID-19 pandemic, one productive area of research has focused on the intricate two- and three-dimensional structures taken on by SARS-CoV-2's RNA genome. These structures control essential viral processes, making them tempting targets for therapeutic intervention. This review focuses on two such structured regions, the frameshift stimulation element (FSE), which controls the translation of viral protein, and the 3' untranslated region (3' UTR), which is thought to regulate genome replication. For the FSE, we discuss its canonical pseudoknot's threaded and unthreaded topologies, as well as the diversity of competing two-dimensional structures formed by local and long-distance base pairing. For the 3' UTR, we review the evidence both for and against the formation of its replication-enabling pseudoknot.
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Affiliation(s)
- Justin Aruda
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA; Harvard Program in Biological and Biomedical Sciences, Division of Medical Sciences, Harvard Medical School, Boston, MA 02115, USA
| | - Scott L Grote
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - Silvi Rouskin
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA.
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2
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Tamayo-Ordóñez YDJ, Rosas-García NM, Tamayo-Ordoñez FA, Ayil-Gutiérrez BA, Bello-López JM, Sosa-Santillán GDJ, Acosta-Cruz E, Anguebes-Franseschi F, Damas-Damas S, Domínguez-May AV, Córdova-Quiroz AV, Tamayo-Ordóñez MC. Genomic Evolution Strategy in SARS-CoV-2 Lineage B: Coevolution of Cis Elements. Curr Issues Mol Biol 2024; 46:5744-5776. [PMID: 38921015 PMCID: PMC11203041 DOI: 10.3390/cimb46060344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 05/14/2024] [Accepted: 05/26/2024] [Indexed: 06/27/2024] Open
Abstract
In the SARS-CoV-2 lineage, RNA elements essential for its viral life cycle, including genome replication and gene expression, have been identified. Still, the precise structures and functions of these RNA regions in coronaviruses remain poorly understood. This lack of knowledge points out the need for further research to better understand these crucial aspects of viral biology and, in time, prepare for future outbreaks. In this research, the in silico analysis of the cis RNA structures that act in the alpha-, beta-, gamma-, and deltacoronavirus genera has provided a detailed view of the presence and adaptation of the structures of these elements in coronaviruses. The results emphasize the importance of these cis elements in viral biology and their variability between different viral variants. Some coronavirus variants in some groups, depending on the cis element (stem-loop1 and -2; pseudoknot stem-loop1 and -2, and s2m), exhibited functional adaptation. Additionally, the conformation flexibility of the s2m element in the SARS variants was determined, suggesting a coevolution of this element in this viral group. The variability in secondary structures suggests genomic adaptations that may be related to replication processes, genetic regulation, as well as the specific pathogenicity of each variant. The results suggest that RNA structures in coronaviruses can adapt and evolve toward different viral variants, which has important implications for viral adaptation, pathogenicity, and future therapeutic strategies.
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Affiliation(s)
- Yahaira de J. Tamayo-Ordóñez
- Laboratorio de Biotecnología Ambiental del Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Tamps, Mexico;
| | - Ninfa M. Rosas-García
- Laboratorio de Biotecnología Ambiental del Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa 88710, Tamps, Mexico;
| | - Francisco A. Tamayo-Ordoñez
- Facultad de Química, Universidad Autónoma del Carmen, Calle 56 N. 4, Av. Concordia Col. Benito Juárez, Ciudad del Carmen 24180, Campeche, Mexico; (F.A.T.-O.); (F.A.-F.); (S.D.-D.); (A.V.C.-Q.)
| | - Benjamín A. Ayil-Gutiérrez
- CONAHCYT—Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Biotecnología Vegetal, Reynosa 88710, Tamps, Mexico;
| | - Juan M. Bello-López
- División de Investigación, Hospital Juárez de México, Ciudad de México 07760, Mexico;
| | - Gerardo de J. Sosa-Santillán
- Laboratorio de Microbiología y Biosíntesis, Departamento de Biotecnología, Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Saltillo 25280, Coahuila, Mexico;
| | - Erika Acosta-Cruz
- Laboratorio de Microbiología Molecular, Departamento de Biotecnología, Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Saltillo 25280, Coahuila, Mexico;
| | - Francisco Anguebes-Franseschi
- Facultad de Química, Universidad Autónoma del Carmen, Calle 56 N. 4, Av. Concordia Col. Benito Juárez, Ciudad del Carmen 24180, Campeche, Mexico; (F.A.T.-O.); (F.A.-F.); (S.D.-D.); (A.V.C.-Q.)
| | - Siprian Damas-Damas
- Facultad de Química, Universidad Autónoma del Carmen, Calle 56 N. 4, Av. Concordia Col. Benito Juárez, Ciudad del Carmen 24180, Campeche, Mexico; (F.A.T.-O.); (F.A.-F.); (S.D.-D.); (A.V.C.-Q.)
| | - Angel V. Domínguez-May
- TecNM, Instituto Tecnológico Superior del Sur del Estado de Yucatán, Road Muna-Felipe Carrillo Puerto, Stretch Oxkutzcab-Akil Km 41+400, Oxkutzcab 97880, Yucatán, Mexico;
| | - Atl Victor Córdova-Quiroz
- Facultad de Química, Universidad Autónoma del Carmen, Calle 56 N. 4, Av. Concordia Col. Benito Juárez, Ciudad del Carmen 24180, Campeche, Mexico; (F.A.T.-O.); (F.A.-F.); (S.D.-D.); (A.V.C.-Q.)
| | - María Concepción Tamayo-Ordóñez
- Laboratorio de Ingeniería Genética, Departamento de Biotecnología, Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Saltillo 25280, Coahuila, Mexico
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3
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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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4
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Bose E, Xiong S, Jones AN. Probing RNA structure and dynamics using nanopore and next generation sequencing. J Biol Chem 2024; 300:107317. [PMID: 38677514 PMCID: PMC11145556 DOI: 10.1016/j.jbc.2024.107317] [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: 07/03/2023] [Revised: 04/10/2024] [Accepted: 04/11/2024] [Indexed: 04/29/2024] Open
Abstract
It has become increasingly evident that the structures RNAs adopt are conformationally dynamic; the various structured states that RNAs sample govern their interactions with other nucleic acids, proteins, and ligands to regulate a myriad of biological processes. Although several biophysical approaches have been developed and used to study the dynamic landscape of structured RNAs, technical limitations have limited their application to all classes of RNA due to variable size and flexibility. Recent advances combining chemical probing experiments with next-generation- and direct sequencing have emerged as an alternative approach to exploring the conformational dynamics of RNA. In this review, we provide a methodological overview of the sequencing-based techniques used to study RNA conformational dynamics. We discuss how different techniques have enabled us to better understand the propensity of RNAs from a variety of different classes to sample multiple conformational states. Finally, we present examples of the ways these techniques have reshaped how we think about RNA structure.
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Affiliation(s)
- Emma Bose
- Department of Chemistry, New York University, New York, New York, USA
| | - Shengwei Xiong
- Department of Chemistry, New York University, New York, New York, USA
| | - Alisha N Jones
- Department of Chemistry, New York University, New York, New York, USA.
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5
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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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6
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Chakraborty C, Bhattacharya M, Sharma AR, Chatterjee S, Agoramoorthy G, Lee SS. Structural Landscape of nsp Coding Genomic Regions of SARS-CoV-2-ssRNA Genome: A Structural Genomics Approach Toward Identification of Druggable Genome, Ligand-Binding Pockets, and Structure-Based Druggability. Mol Biotechnol 2024; 66:641-662. [PMID: 36463562 PMCID: PMC9735222 DOI: 10.1007/s12033-022-00605-x] [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: 05/05/2022] [Accepted: 11/07/2022] [Indexed: 12/05/2022]
Abstract
SARS-CoV-2 has a single-stranded RNA genome (+ssRNA), and synthesizes structural and non-structural proteins (nsps). All 16 nsp are synthesized from the ORF1a, and ORF1b regions associated with different life cycle preprocesses, including replication. The regions of ORF1a synthesizes nsp1 to 11, and ORF1b synthesizes nsp12 to 16. In this paper, we have predicted the secondary structure conformations, entropy & mountain plots, RNA secondary structure in a linear fashion, and 3D structure of nsp coding genes of the SARS-CoV-2 genome. We have also analyzed the A, T, G, C, A+T, and G+C contents, GC-profiling of these genes, showing the range of the GC content from 34.23 to 48.52%. We have observed that the GC-profile value of the nsp coding genomic regions was less (about 0.375) compared to the whole genome (about 0.38). Additionally, druggable pockets were identified from the secondary structure-guided 3D structural conformations. For secondary structure generation of all the nsp coding genes (nsp 1-16), we used a recent algorithm-based tool (deep learning-based) along with the conventional algorithms (centroid and MFE-based) to develop secondary structural conformations, and we found stem-loop, multi-branch loop, pseudoknot, and the bulge structural components, etc. The 3D model shows bound and unbound forms, branched structures, duplex structures, three-way junctions, four-way junctions, etc. Finally, we identified binding pockets of nsp coding genes which will help as a fundamental resource for future researchers to develop RNA-targeted therapeutics using the druggable genome.
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Affiliation(s)
- Chiranjib Chakraborty
- Department of Biotechnology, School of Life Science and Biotechnology, Adamas University, Kolkata, West Bengal, 700126, India.
| | - Manojit Bhattacharya
- Department of Zoology, Fakir Mohan University, Vyasa Vihar, Balasore, Odisha, 756020, India
| | - Ashish Ranjan Sharma
- Institute for Skeletal Aging & Orthopaedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon-si, Gangwon-do, 24252, Republic of Korea
| | - Srijan Chatterjee
- Department of Biotechnology, School of Life Science and Biotechnology, Adamas University, Kolkata, West Bengal, 700126, India
| | | | - Sang-Soo Lee
- Institute for Skeletal Aging & Orthopaedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon-si, Gangwon-do, 24252, Republic of Korea
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7
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Liao Y, Wang H, Liao H, Sun Y, Tan L, Song C, Qiu X, Ding C. Classification, replication, and transcription of Nidovirales. Front Microbiol 2024; 14:1291761. [PMID: 38328580 PMCID: PMC10847374 DOI: 10.3389/fmicb.2023.1291761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/06/2023] [Indexed: 02/09/2024] Open
Abstract
Nidovirales is one order of RNA virus, with the largest single-stranded positive sense RNA genome enwrapped with membrane envelope. It comprises four families (Arterividae, Mesoniviridae, Roniviridae, and Coronaviridae) and has been circulating in humans and animals for almost one century, posing great threat to livestock and poultry,as well as to public health. Nidovirales shares similar life cycle: attachment to cell surface, entry, primary translation of replicases, viral RNA replication in cytoplasm, translation of viral proteins, virion assembly, budding, and release. The viral RNA synthesis is the critical step during infection, including genomic RNA (gRNA) replication and subgenomic mRNAs (sg mRNAs) transcription. gRNA replication requires the synthesis of a negative sense full-length RNA intermediate, while the sg mRNAs transcription involves the synthesis of a nested set of negative sense subgenomic intermediates by a discontinuous strategy. This RNA synthesis process is mediated by the viral replication/transcription complex (RTC), which consists of several enzymatic replicases derived from the polyprotein 1a and polyprotein 1ab and several cellular proteins. These replicases and host factors represent the optimal potential therapeutic targets. Hereby, we summarize the Nidovirales classification, associated diseases, "replication organelle," replication and transcription mechanisms, as well as related regulatory factors.
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Affiliation(s)
- Ying Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Huan Wang
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Huiyu Liao
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Yingjie Sun
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Lei Tan
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Cuiping Song
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Xusheng Qiu
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
| | - Chan Ding
- Department of Avian Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China
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8
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Yi H, Ye R, Xie E, Lu L, Wang Q, Wang S, Sun Y, Tian T, Qiu Y, Wu Q, Zhang G, Wang H. ZNF283, a Krüppel-associated box zinc finger protein, inhibits RNA synthesis of porcine reproductive and respiratory syndrome virus by interacting with Nsp9 and Nsp10. Vet Res 2024; 55:9. [PMID: 38225617 PMCID: PMC10790482 DOI: 10.1186/s13567-023-01263-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 11/15/2023] [Indexed: 01/17/2024] Open
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) is a viral pathogen with substantial economic implications for the global swine industry. The existing vaccination strategies and antiviral drugs offer limited protection. Replication of the viral RNA genome encompasses a complex series of steps, wherein a replication complex is assembled from various components derived from both viral and cellular sources, as well as from the viral genomic RNA template. In this study, we found that ZNF283, a Krüppel-associated box (KRAB) containing zinc finger protein, was upregulated in PRRSV-infected Marc-145 cells and porcine alveolar macrophages and that ZNF283 inhibited PRRSV replication and RNA synthesis. We also found that ZNF283 interacts with the viral proteins Nsp9, an RNA-dependent RNA polymerase, and Nsp10, a helicase. The main regions involved in the interaction between ZNF283 and Nsp9 were determined to be the KRAB domain of ZNF283 and amino acids 178-449 of Nsp9. The KRAB domain of ZNF283 plays a role in facilitating Nsp10 binding. In addition, ZNF283 may have an affinity for the 3' untranslated region of PRRSV. These findings suggest that ZNF283 is an antiviral factor that inhibits PRRSV infection and extend our understanding of the interactions between KRAB-containing zinc finger proteins and viruses.
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Affiliation(s)
- Heyou Yi
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
- Key Laboratory of Animal Pathogen Infection and Immunology of Fujian Province, College of Animal Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, China
| | - Ruirui Ye
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Ermin Xie
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Lechen Lu
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Qiumei Wang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Shaojun Wang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Yankuo Sun
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, China
- National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, 510642, China
| | - Tao Tian
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Yingwu Qiu
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Qianwen Wu
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China
| | - Guihong Zhang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China.
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, China.
- National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, 510642, China.
| | - Heng Wang
- Guangdong Provincial Key Laboratory of Zoonosis Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, 510462, China.
- Maoming Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Maoming, 525000, China.
- National Engineering Research Center for Breeding Swine Industry, South China Agricultural University, Guangzhou, 510642, China.
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Lu S, Luo S, Liu C, Li M, An X, Li M, Hou J, Fan H, Mao P, Tong Y, Song L. Induction of significant neutralizing antibodies against SARS-CoV-2 by a highly attenuated pangolin coronavirus variant with a 104nt deletion at the 3'-UTR. Emerg Microbes Infect 2023; 12:2151383. [PMID: 36453209 PMCID: PMC9769135 DOI: 10.1080/22221751.2022.2151383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
SARS-CoV-2 related coronaviruses (SARS-CoV-2r) from Guangdong and Guangxi pangolins have been implicated in the emergence of SARS-CoV-2 and future pandemics. We previously reported the culture of a SARS-CoV-2r GX_P2V from Guangxi pangolins. Here we report the GX_P2V isolate rapidly adapted to Vero cells by acquiring two genomic mutations: an alanine to valine substitution in the nucleoprotein and a 104-nucleotide deletion in the hypervariable region (HVR) of the 3'-terminus untranslated region (3'-UTR). We further report the characterization of the GX_P2V variant (renamed GX_P2V(short_3UTR)) in in vitro and in vivo infection models. In cultured Vero, BGM and Calu-3 cells, GX_P2V(short_3UTR) had similar robust replication kinetics, and consistently produced minimum cell damage. GX_P2V(short_3UTR) infected golden hamsters and BALB/c mice but was highly attenuated. Golden hamsters infected intranasally had a short duration of productive infection in pulmonary, not extrapulmonary, tissues. These productive infections induced neutralizing antibodies against pseudoviruses of GX_P2V and SARS-CoV-2. Collectively, our data show that the GX_P2V(short_3UTR) is highly attenuated in in vitro and in vivo infection models. Attenuation of the variant is likely partially due to the 104-nt deletion in the HVR in the 3'-UTR. This study furthers our understanding of pangolin coronaviruses pathogenesis and provides novel insights for the design of live attenuated vaccines against SARS-CoV-2.
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Affiliation(s)
- Shanshan Lu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Shengdong Luo
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Beijing, People’s Republic of China
| | - Chang Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Muli Li
- Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, People’s Republic of China
| | - Xiaoping An
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Mengzhe Li
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Jun Hou
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Beijing, People’s Republic of China
| | - Huahao Fan
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China,Huahao Fan Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Panyong Mao
- Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Beijing, People’s Republic of China,Panyong Mao Department of Infectious Diseases, Fifth Medical Center of Chinese PLA General Hospital, Beijing, People’s Republic of China
| | - Yigang Tong
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China,Yigang Tong Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
| | - Lihua Song
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China, Lihua Song Beijing Advanced Innovation Center for Soft Matter Science and Engineering, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, People’s Republic of China
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10
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Lin CH, Hsieh FC, Chang YC, Yang CY, Hsu HW, Yang CC, Tam HMH, Wu HY. Targeting the conserved coronavirus octamer motif GGAAGAGC is a strategy for the development of coronavirus vaccine. Virol J 2023; 20:267. [PMID: 37968733 PMCID: PMC10652495 DOI: 10.1186/s12985-023-02231-8] [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: 09/06/2023] [Accepted: 11/06/2023] [Indexed: 11/17/2023] Open
Abstract
BACKGROUND Coronaviruses are pathogens of humans and animals that cause widespread and costly diseases. The development of effective strategies to combat the threat of coronaviruses is therefore a top priority. The conserved coronavirus octamer motif 5'GGAAGAGC3' exists in the 3' untranslated region of all identified coronaviruses. In the current study, we aimed to examine whether targeting the coronavirus octamer motif GGAAGAGC is a promising approach to develop coronavirus vaccine. METHODS Plaque assays were used to determine the titers of mouse hepatitis virus (MHV)-A59 octamer mutant (MHVoctm) and wild-type (wt) MHV-A59 (MHVwt). Western blotting was used for the determination of translation efficiency of MHVoctm and MHVwt. Plaque assays and RT-qPCR were employed to examine whether MHVoctm was more sensitive to interferon treatment than MHVwt. Weight loss, clinical signs, survival rate, viral RNA detection and histopathological examination were used to evaluate whether MHVoctm was a vaccine candidate against MHVwt infection in BALB/c mice. RESULTS In this study, we showed that (i) the MHVoctm with mutation of coronavirus octamer was able to grow to high titers but attenuated in mice, (ii) with the reduced multiplicity of infection (MOI), the difference in gene expression between MHVoctm and MHVwt became more evident in cultured cells, (iii) MHVoctm was more sensitive to interferon treatment than MHVwt and (iv) mice inoculated with MHVoctm were protected from MHVwt infection. CONCLUSIONS Based on the results obtained from cultured cells, it was suggested that the synergistic effects of octamer mutation, multiplicity of infection and immune response may be a mechanism explaining the distinct phenotypes of octamer-mutated coronavirus in cell culture and mice. In addition, targeting the conserved coronavirus octamer motif is a strategy for development of coronavirus vaccine. Since the conserved octamer exists in all coronaviruses, this strategy of targeting the conserved octamer motif can also be applied to other human and animal coronaviruses for the development of coronavirus vaccines, especially the emergence of novel coronaviruses such as SARS-CoV-2, saving time and cost for vaccine development and disease control.
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Grants
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
- 109-2313-B-005 -013 -MY3, 110-2327-B-005 -003, 111-2327-B-005 -003 and 112-2313-B-005-041 National Science and Technology Council, Taiwan, R.O.C.
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Affiliation(s)
- Ching-Hung Lin
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Feng-Cheng Hsieh
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Yu-Chia Chang
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Cheng-Yao Yang
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Hsuan-Wei Hsu
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Chun-Chun Yang
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Hon-Man-Herman Tam
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Hung-Yi Wu
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, 40227, Taiwan.
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11
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Schmidt N, Ganskih S, Wei Y, Gabel A, Zielinski S, Keshishian H, Lareau CA, Zimmermann L, Makroczyova J, Pearce C, Krey K, Hennig T, Stegmaier S, Moyon L, Horlacher M, Werner S, Aydin J, Olguin-Nava M, Potabattula R, Kibe A, Dölken L, Smyth RP, Caliskan N, Marsico A, Krempl C, Bodem J, Pichlmair A, Carr SA, Chlanda P, Erhard F, Munschauer M. SND1 binds SARS-CoV-2 negative-sense RNA and promotes viral RNA synthesis through NSP9. Cell 2023; 186:4834-4850.e23. [PMID: 37794589 PMCID: PMC10617981 DOI: 10.1016/j.cell.2023.09.002] [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: 11/13/2022] [Revised: 07/13/2023] [Accepted: 09/01/2023] [Indexed: 10/06/2023]
Abstract
Regulation of viral RNA biogenesis is fundamental to productive SARS-CoV-2 infection. To characterize host RNA-binding proteins (RBPs) involved in this process, we biochemically identified proteins bound to genomic and subgenomic SARS-CoV-2 RNAs. We find that the host protein SND1 binds the 5' end of negative-sense viral RNA and is required for SARS-CoV-2 RNA synthesis. SND1-depleted cells form smaller replication organelles and display diminished virus growth kinetics. We discover that NSP9, a viral RBP and direct SND1 interaction partner, is covalently linked to the 5' ends of positive- and negative-sense RNAs produced during infection. These linkages occur at replication-transcription initiation sites, consistent with NSP9 priming viral RNA synthesis. Mechanistically, SND1 remodels NSP9 occupancy and alters the covalent linkage of NSP9 to initiating nucleotides in viral RNA. Our findings implicate NSP9 in the initiation of SARS-CoV-2 RNA synthesis and unravel an unsuspected role of a cellular protein in orchestrating viral RNA production.
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Affiliation(s)
- Nora Schmidt
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Sabina Ganskih
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Yuanjie Wei
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Alexander Gabel
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Sebastian Zielinski
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | | | - Caleb A Lareau
- Program in Computational and System Biology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Liv Zimmermann
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Jana Makroczyova
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | | | - Karsten Krey
- School of Medicine, Institute of Virology, Technical University of Munich, Munich, Germany
| | - Thomas Hennig
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Sebastian Stegmaier
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Lambert Moyon
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Marc Horlacher
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Simone Werner
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Jens Aydin
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Marco Olguin-Nava
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Ramya Potabattula
- Institute of Human Genetics, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Anuja Kibe
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Lars Dölken
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Redmond P Smyth
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Neva Caliskan
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
| | - Annalisa Marsico
- Computational Health Center, Helmholtz Center Munich, Munich, Germany
| | - Christine Krempl
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Jochen Bodem
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany
| | - Andreas Pichlmair
- School of Medicine, Institute of Virology, Technical University of Munich, Munich, Germany; German Center for Infection Research (DZIF), Munich Partner Site, Munich, Germany
| | - Steven A Carr
- Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Petr Chlanda
- Schaller Research Group, Department of Infectious Diseases, Virology, Heidelberg University Hospital, Heidelberg, Germany
| | - Florian Erhard
- Institute for Virology and Immunobiology, Julius-Maximilians-University Würzburg, Würzburg, Germany; Faculty for Computer and Data Science, University of Regensburg, Regensburg, Germany
| | - Mathias Munschauer
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz Centre for Infection Research (HZI), Würzburg, Germany; Faculty of Medicine, Julius-Maximilians-University Würzburg, Würzburg, Germany.
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12
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Castillo G, Mora-Díaz JC, Breuer M, Singh P, Nelli RK, Giménez-Lirola LG. Molecular mechanisms of human coronavirus NL63 infection and replication. Virus Res 2023; 327:199078. [PMID: 36813239 PMCID: PMC9944649 DOI: 10.1016/j.virusres.2023.199078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/24/2023]
Abstract
Human coronavirus NL63 (HCoV-NL63) is spread globally, causing upper and lower respiratory tract infections mainly in young children. HCoV-NL63 shares a host receptor (ACE2) with severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2 but, unlike them, HCoV-NL63 primarily develops into self-limiting mild to moderate respiratory disease. Although with different efficiency, both HCoV-NL63 and SARS-like CoVs infect ciliated respiratory cells using ACE2 as receptor for binding and cell entry. Working with SARS-like CoVs require access to BSL-3 facilities, while HCoV-NL63 research can be performed at BSL-2 laboratories. Thus, HCoV-NL63 could be used as a safer surrogate for comparative studies on receptor dynamics, infectivity and virus replication, disease mechanism, and potential therapeutic interventions against SARS-like CoVs. This prompted us to review the current knowledge on the infection mechanism and replication of HCoV-NL63. Specifically, after a brief overview on the taxonomy, genomic organization and virus structure, this review compiles the current HCoV-NL63-related research in virus entry and replication mechanism, including virus attachment, endocytosis, genome translation, and replication and transcription. Furthermore, we reviewed cumulative knowledge on the susceptibility of different cells to HCoV-NL63 infection in vitro, which is essential for successful virus isolation and propagation, and contribute to address different scientific questions from basic science to the development and assessment of diagnostic tools, and antiviral therapies. Finally, we discussed different antiviral strategies that have been explored to suppress replication of HCoV-NL63, and other related human coronaviruses, by either targeting the virus or enhancing host antiviral mechanisms.
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Affiliation(s)
- Gino Castillo
- Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, 1850 Christensen Drive, Ames, IA 50011, USA
| | - Juan Carlos Mora-Díaz
- Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, 1850 Christensen Drive, Ames, IA 50011, USA
| | - Mary Breuer
- Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, 1850 Christensen Drive, Ames, IA 50011, USA
| | - Pallavi Singh
- Department of Biological Sciences, Northern Illinois University, DeKalb, IL 60115, USA
| | - Rahul K Nelli
- Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, 1850 Christensen Drive, Ames, IA 50011, USA
| | - Luis G Giménez-Lirola
- Department of Veterinary Diagnostic and Production Animal Medicine, Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Iowa State University, 1850 Christensen Drive, Ames, IA 50011, USA.
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13
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Alemrajabi M, Macias Calix K, Assis R. Epistasis-Driven Evolution of the SARS-CoV-2 Secondary Structure. J Mol Evol 2022; 90:429-437. [PMID: 36178491 PMCID: PMC9523185 DOI: 10.1007/s00239-022-10073-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/02/2022] [Indexed: 11/25/2022]
Abstract
Epistasis is an evolutionary phenomenon whereby the fitness effect of a mutation depends on the genetic background in which it arises. A key source of epistasis in an RNA molecule is its secondary structure, which contains functionally important topological motifs held together by hydrogen bonds between Watson–Crick (WC) base pairs. Here we study epistasis in the secondary structure of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by examining properties of derived alleles arising from substitution mutations at ancestral WC base-paired and unpaired (UP) sites in 15 conserved topological motifs across the genome. We uncover fewer derived alleles and lower derived allele frequencies at WC than at UP sites, supporting the hypothesis that modifications to the secondary structure are often deleterious. At WC sites, we also find lower derived allele frequencies for mutations that abolish base pairing than for those that yield G·U “wobbles,” illustrating that weak base pairing can partially preserve the integrity of the secondary structure. Last, we show that WC sites under the strongest epistatic constraint reside in a three-stemmed pseudoknot motif that plays an essential role in programmed ribosomal frameshifting, whereas those under the weakest epistatic constraint are located in 3’ UTR motifs that regulate viral replication and pathogenicity. Our findings demonstrate the importance of epistasis in the evolution of the SARS-CoV-2 secondary structure, as well as highlight putative structural and functional targets of different forms of natural selection.
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Affiliation(s)
- Mahsa Alemrajabi
- Department of Physics, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Ksenia Macias Calix
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Raquel Assis
- Department of Electrical Engineering and Computer Science, Florida Atlantic University, Boca Raton, FL, 33431, USA.
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Boca Raton, FL, 33431, USA.
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14
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Lessons Learned and Yet-to-Be Learned on the Importance of RNA Structure in SARS-CoV-2 Replication. Microbiol Mol Biol Rev 2022; 86:e0005721. [PMID: 35862724 PMCID: PMC9491204 DOI: 10.1128/mmbr.00057-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
SARS-CoV-2, the etiological agent responsible for the COVID-19 pandemic, is a member of the virus family Coronaviridae, known for relatively extensive (~30-kb) RNA genomes that not only encode for numerous proteins but are also capable of forming elaborate structures. As highlighted in this review, these structures perform critical functions in various steps of the viral life cycle, ultimately impacting pathogenesis and transmissibility. We examine these elements in the context of coronavirus evolutionary history and future directions for curbing the spread of SARS-CoV-2 and other potential human coronaviruses. While we focus on structures supported by a variety of biochemical, biophysical, and/or computational methods, we also touch here on recent evidence for novel structures in both protein-coding and noncoding regions of the genome, including an assessment of the potential role for RNA structure in the controversial finding of SARS-CoV-2 integration in “long COVID” patients. This review aims to serve as a consolidation of previous works on coronavirus and more recent investigation of SARS-CoV-2, emphasizing the need for improved understanding of the role of RNA structure in the evolution and adaptation of these human viruses.
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15
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Kippes O, Thorn A, Santoni G. Structural biology of SARS-CoV-2 nucleocapsid. CRYSTALLOGR REV 2022. [DOI: 10.1080/0889311x.2022.2072835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Oliver Kippes
- Institut für Nanostruktur und Festkörperphysik, Universität Hamburg, Hamburg, Germany
| | - Andrea Thorn
- Institut für Nanostruktur und Festkörperphysik, Universität Hamburg, Hamburg, Germany
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16
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Grellet E, L'Hôte I, Goulet A, Imbert I. Replication of the coronavirus genome: A paradox among positive-strand RNA viruses. J Biol Chem 2022; 298:101923. [PMID: 35413290 PMCID: PMC8994683 DOI: 10.1016/j.jbc.2022.101923] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 03/22/2022] [Accepted: 03/24/2022] [Indexed: 01/18/2023] Open
Abstract
Coronavirus (CoV) genomes consist of positive-sense single-stranded RNA and are among the largest viral RNAs known to date (∼30 kb). As a result, CoVs deploy sophisticated mechanisms to replicate these extraordinarily large genomes as well as to transcribe subgenomic messenger RNAs. Since 2003, with the emergence of three highly pathogenic CoVs (SARS-CoV, MERS-CoV, and SARS-CoV-2), significant progress has been made in the molecular characterization of the viral proteins and key mechanisms involved in CoV RNA genome replication. For example, to allow for the maintenance and integrity of their large RNA genomes, CoVs have acquired RNA proofreading 3'-5' exoribonuclease activity (in nonstructural protein nsp14). In order to replicate the large genome, the viral-RNA-dependent RNA polymerase (RdRp; in nsp12) is supplemented by a processivity factor (made of the viral complex nsp7/nsp8), making it the fastest known RdRp. Lastly, a viral structural protein, the nucleocapsid (N) protein, which is primarily involved in genome encapsidation, is required for efficient viral replication and transcription. Therefore, CoVs are a paradox among positive-strand RNA viruses in the sense that they use both a processivity factor and have proofreading activity reminiscent of DNA organisms in addition to structural proteins that mediate efficient RNA synthesis, commonly used by negative-strand RNA viruses. In this review, we present a historical perspective of these unsuspected discoveries and detail the current knowledge on the core replicative machinery deployed by CoVs.
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Affiliation(s)
- Emeline Grellet
- Aix Marseille Université, Centre National de la Recherche Scientifique, AMU CNRS UMR 7255, LISM, Marseille, France
| | - India L'Hôte
- Aix Marseille Université, Centre National de la Recherche Scientifique, AMU CNRS UMR 7255, LISM, Marseille, France
| | - Adeline Goulet
- Aix Marseille Université, Centre National de la Recherche Scientifique, AMU CNRS UMR 7255, LISM, Marseille, France
| | - Isabelle Imbert
- Aix Marseille Université, Centre National de la Recherche Scientifique, AMU CNRS UMR 7255, LISM, Marseille, France.
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17
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Nikolaidis M, Markoulatos P, Van de Peer Y, Oliver SG, Amoutzias GD. The Neighborhood of the Spike Gene Is a Hotspot for Modular Intertypic Homologous and Nonhomologous Recombination in Coronavirus Genomes. Mol Biol Evol 2022; 39:msab292. [PMID: 34638137 PMCID: PMC8549283 DOI: 10.1093/molbev/msab292] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Coronaviruses (CoVs) have very large RNA viral genomes with a distinct genomic architecture of core and accessory open reading frames (ORFs). It is of utmost importance to understand their patterns and limits of homologous and nonhomologous recombination, because such events may affect the emergence of novel CoV strains, alter their host range, infection rate, tissue tropism pathogenicity, and their ability to escape vaccination programs. Intratypic recombination among closely related CoVs of the same subgenus has often been reported; however, the patterns and limits of genomic exchange between more distantly related CoV lineages (intertypic recombination) need further investigation. Here, we report computational/evolutionary analyses that clearly demonstrate a substantial ability for CoVs of different subgenera to recombine. Furthermore, we show that CoVs can obtain-through nonhomologous recombination-accessory ORFs from core ORFs, exchange accessory ORFs with different CoV genera, with other viruses (i.e., toroviruses, influenza C/D, reoviruses, rotaviruses, astroviruses) and even with hosts. Intriguingly, most of these radical events result from double crossovers surrounding the Spike ORF, thus highlighting both the instability and mobile nature of this genomic region. Although many such events have often occurred during the evolution of various CoVs, the genomic architecture of the relatively young SARS-CoV/SARS-CoV-2 lineage so far appears to be stable.
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Affiliation(s)
- Marios Nikolaidis
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Panayotis Markoulatos
- Microbial Biotechnology-Molecular Bacteriology-Virology Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Yves Van de Peer
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium
- Center for Plant Systems Biology, VIB, Ghent, Belgium
- Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
- College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Stephen G Oliver
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Grigorios D Amoutzias
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
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18
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Amoutzias GD, Nikolaidis M, Tryfonopoulou E, Chlichlia K, Markoulatos P, Oliver SG. The Remarkable Evolutionary Plasticity of Coronaviruses by Mutation and Recombination: Insights for the COVID-19 Pandemic and the Future Evolutionary Paths of SARS-CoV-2. Viruses 2022; 14:78. [PMID: 35062282 PMCID: PMC8778387 DOI: 10.3390/v14010078] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 12/22/2021] [Accepted: 12/31/2021] [Indexed: 12/13/2022] Open
Abstract
Coronaviruses (CoVs) constitute a large and diverse subfamily of positive-sense single-stranded RNA viruses. They are found in many mammals and birds and have great importance for the health of humans and farm animals. The current SARS-CoV-2 pandemic, as well as many previous epidemics in humans that were of zoonotic origin, highlights the importance of studying the evolution of the entire CoV subfamily in order to understand how novel strains emerge and which molecular processes affect their adaptation, transmissibility, host/tissue tropism, and patho non-homologous genicity. In this review, we focus on studies over the last two years that reveal the impact of point mutations, insertions/deletions, and intratypic/intertypic homologous and non-homologous recombination events on the evolution of CoVs. We discuss whether the next generations of CoV vaccines should be directed against other CoV proteins in addition to or instead of spike. Based on the observed patterns of molecular evolution for the entire subfamily, we discuss five scenarios for the future evolutionary path of SARS-CoV-2 and the COVID-19 pandemic. Finally, within this evolutionary context, we discuss the recently emerged Omicron (B.1.1.529) VoC.
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Affiliation(s)
- Grigorios D. Amoutzias
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500 Larissa, Greece;
| | - Marios Nikolaidis
- Bioinformatics Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500 Larissa, Greece;
| | - Eleni Tryfonopoulou
- Laboratory of Molecular Immunology, Department of Molecular Biology and Genetics, Democritus University of Thrace, University Campus-Dragana, 68100 Alexandroupolis, Greece; (E.T.); (K.C.)
| | - Katerina Chlichlia
- Laboratory of Molecular Immunology, Department of Molecular Biology and Genetics, Democritus University of Thrace, University Campus-Dragana, 68100 Alexandroupolis, Greece; (E.T.); (K.C.)
| | - Panayotis Markoulatos
- Microbial Biotechnology-Molecular Bacteriology-Virology Laboratory, Department of Biochemistry and Biotechnology, University of Thessaly, 41500 Larissa, Greece;
| | - Stephen G. Oliver
- Department of Biochemistry, University of Cambridge, Sanger Building, 80 Tennis Court Road, Cambridge CB2 1GA, UK
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19
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Hu Y, Xie X, Yang L, Wang A. A Comprehensive View on the Host Factors and Viral Proteins Associated With Porcine Epidemic Diarrhea Virus Infection. Front Microbiol 2021; 12:762358. [PMID: 34950116 PMCID: PMC8688245 DOI: 10.3389/fmicb.2021.762358] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 10/26/2021] [Indexed: 11/17/2022] Open
Abstract
Porcine epidemic diarrhea virus (PEDV), a coronavirus pathogen of the pig intestinal tract, can cause fatal watery diarrhea in piglets, thereby causing huge economic losses to swine industries around the world. The pathogenesis of PEDV has intensively been studied; however, the viral proteins of PEDV and the host factors in target cells, as well as their interactions, which are the foundation of the molecular mechanisms of viral infection, remain to be summarized and updated. PEDV has multiple important structural and functional proteins, which play various roles in the process of virus infection. Among them, the S and N proteins play vital roles in biological processes related to PEDV survival via interacting with the host cell proteins. Meanwhile, a number of host factors including receptors are required for the infection of PEDV via interacting with the viral proteins, thereby affecting the reproduction of PEDV and contributing to its life cycle. In this review, we provide an updated understanding of viral proteins and host factors, as well as their interactions in terms of PEDV infection. Additionally, the effects of cellular factors, events, and signaling pathways on PEDV infection are also discussed. Thus, these comprehensive and profound insights should facilitate for the further investigations, control, and prevention of PEDV infection.
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Affiliation(s)
- Yi Hu
- Laboratory of Animal Disease Prevention and Control and Animal Model, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Xiaohong Xie
- Hunan Engineering Research Center of Livestock and Poultry Health Care, Colleges of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Lingchen Yang
- Laboratory of Animal Disease Prevention and Control and Animal Model, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China
| | - Aibing Wang
- Laboratory of Animal Disease Prevention and Control and Animal Model, Hunan Provincial Key Laboratory of Protein Engineering in Animal Vaccines, College of Veterinary Medicine, Hunan Agricultural University, Changsha, China.,PCB Biotechnology, LLC, Rockville, MD, United States
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20
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Hegde S, Tang Z, Zhao J, Wang J. Inhibition of SARS-CoV-2 by Targeting Conserved Viral RNA Structures and Sequences. Front Chem 2021; 9:802766. [PMID: 35004621 PMCID: PMC8733332 DOI: 10.3389/fchem.2021.802766] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 11/29/2021] [Indexed: 01/18/2023] Open
Abstract
The ongoing COVID-19/Severe Acute Respiratory Syndrome CoV-2 (SARS-CoV-2) pandemic has become a significant threat to public health and has hugely impacted societies globally. Targeting conserved SARS-CoV-2 RNA structures and sequences essential for viral genome translation is a novel approach to inhibit viral infection and progression. This new pharmacological modality compasses two classes of RNA-targeting molecules: 1) synthetic small molecules that recognize secondary or tertiary RNA structures and 2) antisense oligonucleotides (ASOs) that recognize the RNA primary sequence. These molecules can also serve as a "bait" fragment in RNA degrading chimeras to eliminate the viral RNA genome. This new type of chimeric RNA degrader is recently named ribonuclease targeting chimera or RIBOTAC. This review paper summarizes the sequence conservation in SARS-CoV-2 and the current development of RNA-targeting molecules to combat this virus. These RNA-binding molecules will also serve as an emerging class of antiviral drug candidates that might pivot to address future viral outbreaks.
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Affiliation(s)
| | | | | | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, United States
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21
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Abstract
The ongoing Covid-19 pandemic has spurred research in the biology of the nidovirus severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Much focus has been on the viral RNA synthesis machinery due to its fundamental role in viral propagation. The central and essential enzyme of the RNA synthesis process, the RNA-dependent RNA polymerase (RdRp), functions in conjunction with a coterie of viral-encoded enzymes that mediate crucial nucleic acid transactions. Some of these enzymes share common features with other RNA viruses, while others play roles unique to nidoviruses or CoVs. The RdRps are proven targets for viral pathogens, and many of the other nucleic acid processing enzymes are promising targets. The purpose of this review is to summarize recent advances in our understanding of the mechanisms of RNA synthesis in CoVs. By reflecting on these studies, we hope to emphasize the remaining gaps in our knowledge. The recent onslaught of structural information related to SARS-CoV-2 RNA synthesis, in combination with previous structural, genetic and biochemical studies, have vastly improved our understanding of how CoVs replicate and process their genomic RNA. Structural biology not only provides a blueprint for understanding the function of the enzymes and cofactors in molecular detail, but also provides a basis for drug design and optimization. The concerted efforts of researchers around the world, in combination with the renewed urgency toward understanding this deadly family of viruses, may eventually yield new and improved antivirals that provide relief to the current global devastation.
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Affiliation(s)
- Brandon Malone
- The Rockefeller University, New York, New York, United States
| | | | - Seth A Darst
- The Rockefeller University, New York, New York, United States.
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22
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Zhang Y, Huang K, Xie D, Lau JY, Shen W, Li P, Wang D, Zou Z, Shi S, Ren H, Wang Y, Mao Y, Jin M, Kudla G, Zhao Z. In vivo structure and dynamics of the SARS-CoV-2 RNA genome. Nat Commun 2021; 12:5695. [PMID: 34584097 PMCID: PMC8478942 DOI: 10.1038/s41467-021-25999-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 09/10/2021] [Indexed: 02/08/2023] Open
Abstract
The dynamics of SARS-CoV-2 RNA structure and their functional relevance are largely unknown. Here we develop a simplified SPLASH assay and comprehensively map the in vivo RNA-RNA interactome of SARS-CoV-2 genome across viral life cycle. We report canonical and alternative structures including 5'-UTR and 3'-UTR, frameshifting element (FSE) pseudoknot and genome cyclization in both cells and virions. We provide direct evidence of interactions between Transcription Regulating Sequences, which facilitate discontinuous transcription. In addition, we reveal alternative short and long distance arches around FSE. More importantly, we find that within virions, while SARS-CoV-2 genome RNA undergoes intensive compaction, genome domains remain stable but with strengthened demarcation of local domains and weakened global cyclization. Taken together, our analysis reveals the structural basis for the regulation of replication, discontinuous transcription and translational frameshifting, the alternative conformations and the maintenance of global genome organization during the whole life cycle of SARS-CoV-2, which we anticipate will help develop better antiviral strategies.
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Affiliation(s)
- Yan Zhang
- Beijing institute of Biotechnology, Beijing, China
| | - Kun Huang
- Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Dejian Xie
- Wuhan Frasergen Bioinformatics Co., Ltd, Wuhan, China
| | - Jian You Lau
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh, EH4 2XU, UK
| | - Wenlong Shen
- Beijing institute of Biotechnology, Beijing, China
| | - Ping Li
- Beijing institute of Biotechnology, Beijing, China
| | - Dong Wang
- Department of Microbiology, University of Hong Kong, Queen Mary Hospital, Pokfulam, Hong Kong, China
| | - Zhong Zou
- Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shu Shi
- Beijing institute of Biotechnology, Beijing, China
| | | | | | - Youzhi Mao
- Wuhan Frasergen Bioinformatics Co., Ltd, Wuhan, China
| | - Meilin Jin
- Unit of Animal Infectious Diseases, National Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.
| | - Grzegorz Kudla
- MRC Human Genetics Unit, University of Edinburgh, Edinburgh, EH4 2XU, UK.
| | - Zhihu Zhao
- Beijing institute of Biotechnology, Beijing, China.
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23
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Sreeramulu S, Richter C, Berg H, Wirtz Martin MA, Ceylan B, Matzel T, Adam J, Altincekic N, Azzaoui K, Bains JK, Blommers MJJ, Ferner J, Fürtig B, Göbel M, Grün JT, Hengesbach M, Hohmann KF, Hymon D, Knezic B, Martins JN, Mertinkus KR, Niesteruk A, Peter SA, Pyper DJ, Qureshi NS, Scheffer U, Schlundt A, Schnieders R, Stirnal E, Sudakov A, Tröster A, Vögele J, Wacker A, Weigand JE, Wirmer‐Bartoschek J, Wöhnert J, Schwalbe H. Exploring the Druggability of Conserved RNA Regulatory Elements in the SARS‐CoV‐2 Genome. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202103693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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24
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Sreeramulu S, Richter C, Berg H, Wirtz Martin MA, Ceylan B, Matzel T, Adam J, Altincekic N, Azzaoui K, Bains JK, Blommers MJJ, Ferner J, Fürtig B, Göbel M, Grün JT, Hengesbach M, Hohmann KF, Hymon D, Knezic B, Martins JN, Mertinkus KR, Niesteruk A, Peter SA, Pyper DJ, Qureshi NS, Scheffer U, Schlundt A, Schnieders R, Stirnal E, Sudakov A, Tröster A, Vögele J, Wacker A, Weigand JE, Wirmer‐Bartoschek J, Wöhnert J, Schwalbe H. Exploring the Druggability of Conserved RNA Regulatory Elements in the SARS-CoV-2 Genome. Angew Chem Int Ed Engl 2021; 60:19191-19200. [PMID: 34161644 PMCID: PMC8426693 DOI: 10.1002/anie.202103693] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/03/2021] [Indexed: 12/12/2022]
Abstract
SARS-CoV-2 contains a positive single-stranded RNA genome of approximately 30 000 nucleotides. Within this genome, 15 RNA elements were identified as conserved between SARS-CoV and SARS-CoV-2. By nuclear magnetic resonance (NMR) spectroscopy, we previously determined that these elements fold independently, in line with data from in vivo and ex-vivo structural probing experiments. These elements contain non-base-paired regions that potentially harbor ligand-binding pockets. Here, we performed an NMR-based screening of a poised fragment library of 768 compounds for binding to these RNAs, employing three different 1 H-based 1D NMR binding assays. The screening identified common as well as RNA-element specific hits. The results allow selection of the most promising of the 15 RNA elements as putative drug targets. Based on the identified hits, we derive key functional units and groups in ligands for effective targeting of the RNA of SARS-CoV-2.
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25
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Brant AC, Tian W, Majerciak V, Yang W, Zheng ZM. SARS-CoV-2: from its discovery to genome structure, transcription, and replication. Cell Biosci 2021; 11:136. [PMID: 34281608 PMCID: PMC8287290 DOI: 10.1186/s13578-021-00643-z] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 06/30/2021] [Indexed: 02/08/2023] Open
Abstract
SARS-CoV-2 is an extremely contagious respiratory virus causing adult atypical pneumonia COVID-19 with severe acute respiratory syndrome (SARS). SARS-CoV-2 has a single-stranded, positive-sense RNA (+RNA) genome of ~ 29.9 kb and exhibits significant genetic shift from different isolates. After entering the susceptible cells expressing both ACE2 and TMPRSS2, the SARS-CoV-2 genome directly functions as an mRNA to translate two polyproteins from the ORF1a and ORF1b region, which are cleaved by two viral proteases into sixteen non-structural proteins (nsp1-16) to initiate viral genome replication and transcription. The SARS-CoV-2 genome also encodes four structural (S, E, M and N) and up to six accessory (3a, 6, 7a, 7b, 8, and 9b) proteins, but their translation requires newly synthesized individual subgenomic RNAs (sgRNA) in the infected cells. Synthesis of the full-length viral genomic RNA (gRNA) and sgRNAs are conducted inside double-membrane vesicles (DMVs) by the viral replication and transcription complex (RTC), which comprises nsp7, nsp8, nsp9, nsp12, nsp13 and a short RNA primer. To produce sgRNAs, RTC starts RNA synthesis from the highly structured gRNA 3' end and switches template at various transcription regulatory sequence (TRSB) sites along the gRNA body probably mediated by a long-distance RNA-RNA interaction. The TRS motif in the gRNA 5' leader (TRSL) is responsible for the RNA-RNA interaction with the TRSB upstream of each ORF and skipping of the viral genome in between them to produce individual sgRNAs. Abundance of individual sgRNAs and viral gRNA synthesized in the infected cells depend on the location and read-through efficiency of each TRSB. Although more studies are needed, the unprecedented COVID-19 pandemic has taught the world a painful lesson that is to invest and proactively prepare future emergence of other types of coronaviruses and any other possible biological horrors.
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Affiliation(s)
- Ayslan Castro Brant
- Tumor Virus RNA Biology Section, HIV DRP, National Cancer Institute, NIH, Frederick, MD, USA
| | - Wei Tian
- Mechanism of DNA Repair, Replication, and Recombination Section, Laboratory of Molecular Biology, NIDDK, Bethesda, MD, USA
| | - Vladimir Majerciak
- Tumor Virus RNA Biology Section, HIV DRP, National Cancer Institute, NIH, Frederick, MD, USA
| | - Wei Yang
- Mechanism of DNA Repair, Replication, and Recombination Section, Laboratory of Molecular Biology, NIDDK, Bethesda, MD, USA.
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV DRP, National Cancer Institute, NIH, Frederick, MD, USA.
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26
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Yamada T, Sato S, Sotoyama Y, Orba Y, Sawa H, Yamauchi H, Sasaki M, Takaoka A. RIG-I triggers a signaling-abortive anti-SARS-CoV-2 defense in human lung cells. Nat Immunol 2021; 22:820-828. [PMID: 33976430 DOI: 10.1038/s41590-021-00942-0] [Citation(s) in RCA: 154] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 04/26/2021] [Indexed: 12/19/2022]
Abstract
Efficient immune responses against viral infection are determined by sufficient activation of nucleic acid sensor-mediated innate immunity1,2. Coronavirus disease 2019, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), remains an ongoing global pandemic. It is an urgent challenge to clarify the innate recognition mechanism to control this virus. Here we show that retinoic acid-inducible gene-I (RIG-I) sufficiently restrains SARS-CoV-2 replication in human lung cells in a type I/III interferon (IFN)-independent manner. RIG-I recognizes the 3' untranslated region of the SARS-CoV-2 RNA genome via the helicase domains, but not the C-terminal domain. This new mode of RIG-I recognition does not stimulate its ATPase, thereby aborting the activation of the conventional mitochondrial antiviral-signaling protein-dependent pathways, which is in accordance with lack of cytokine induction. Nevertheless, the interaction of RIG-I with the viral genome directly abrogates viral RNA-dependent RNA polymerase mediation of the first step of replication. Consistently, genetic ablation of RIG-I allows lung cells to produce viral particles that expressed the viral spike protein. By contrast, the anti-SARS-CoV-2 activity was restored by all-trans retinoic acid treatment through upregulation of RIG-I protein expression in primary lung cells derived from patients with chronic obstructive pulmonary disease. Thus, our findings demonstrate the distinctive role of RIG-I as a restraining factor in the early phase of SARS-CoV-2 infection in human lung cells.
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Affiliation(s)
- Taisho Yamada
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
- Molecular Medical Biochemistry Unit, Biological Chemistry and Engineering Course, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Seiichi Sato
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
- Molecular Medical Biochemistry Unit, Biological Chemistry and Engineering Course, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Yuki Sotoyama
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
- Molecular Medical Biochemistry Unit, Biological Chemistry and Engineering Course, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan
| | - Yasuko Orba
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Hirofumi Sawa
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
- International Collaboration Unit, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
- Global Virus Network, Baltimore, MD, USA
| | - Hajime Yamauchi
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan
| | - Michihito Sasaki
- Division of Molecular Pathobiology, Research Center for Zoonosis Control, Hokkaido University, Sapporo, Japan
| | - Akinori Takaoka
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Japan.
- Molecular Medical Biochemistry Unit, Biological Chemistry and Engineering Course, Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan.
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27
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Shu B, Kirby MK, Davis WG, Warnes C, Liddell J, Liu J, Wu KH, Hassell N, Benitez AJ, Wilson MM, Keller MW, Rambo-Martin BL, Camara Y, Winter J, Kondor RJ, Zhou B, Spies S, Rose LE, Winchell JM, Limbago BM, Wentworth DE, Barnes JR. Multiplex Real-Time Reverse Transcription PCR for Influenza A Virus, Influenza B Virus, and Severe Acute Respiratory Syndrome Coronavirus 2. Emerg Infect Dis 2021; 27:1821-1830. [PMID: 34152951 PMCID: PMC8237866 DOI: 10.3201/eid2707.210462] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019, and the outbreak rapidly evolved into the current coronavirus disease pandemic. SARS-CoV-2 is a respiratory virus that causes symptoms similar to those caused by influenza A and B viruses. On July 2, 2020, the US Food and Drug Administration granted emergency use authorization for in vitro diagnostic use of the Influenza SARS-CoV-2 Multiplex Assay. This assay detects influenza A virus at 102.0, influenza B virus at 102.2, and SARS-CoV-2 at 100.3 50% tissue culture or egg infectious dose, or as few as 5 RNA copies/reaction. The simultaneous detection and differentiation of these 3 major pathogens increases overall testing capacity, conserves resources, identifies co-infections, and enables efficient surveillance of influenza viruses and SARS-CoV-2.
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28
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Ryder SP, Morgan BR, Coskun P, Antkowiak K, Massi F. Analysis of Emerging Variants in Structured Regions of the SARS-CoV-2 Genome. Evol Bioinform Online 2021; 17:11769343211014167. [PMID: 34017166 PMCID: PMC8114311 DOI: 10.1177/11769343211014167] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 03/29/2021] [Indexed: 01/11/2023] Open
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has motivated a widespread effort to understand its epidemiology and pathogenic mechanisms. Modern high-throughput sequencing technology has led to the deposition of vast numbers of SARS-CoV-2 genome sequences in curated repositories, which have been useful in mapping the spread of the virus around the globe. They also provide a unique opportunity to observe virus evolution in real time. Here, we evaluate two sets of SARS-CoV-2 genomic sequences to identify emerging variants within structured cis-regulatory elements of the SARS-CoV-2 genome. Overall, 20 variants are present at a minor allele frequency of at least 0.5%. Several enhance the stability of Stem Loop 1 in the 5' untranslated region (UTR), including a group of co-occurring variants that extend its length. One appears to modulate the stability of the frameshifting pseudoknot between ORF1a and ORF1b, and another perturbs a bi-ss molecular switch in the 3'UTR. Finally, 5 variants destabilize structured elements within the 3'UTR hypervariable region, including the S2M (stem loop 2 m) selfish genetic element, raising questions as to the functional relevance of these structures in viral replication. Two of the most abundant variants appear to be caused by RNA editing, suggesting host-viral defense contributes to SARS-CoV-2 genome heterogeneity. Our analysis has implications for the development of therapeutics that target viral cis-regulatory RNA structures or sequences.
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Affiliation(s)
- Sean P Ryder
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Brittany R Morgan
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Peren Coskun
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Katianna Antkowiak
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
| | - Francesca Massi
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA, USA
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29
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Huston NC, Wan H, Strine MS, de Cesaris Araujo Tavares R, Wilen CB, Pyle AM. Comprehensive in vivo secondary structure of the SARS-CoV-2 genome reveals novel regulatory motifs and mechanisms. Mol Cell 2021; 81:584-598.e5. [PMID: 33444546 PMCID: PMC7775661 DOI: 10.1016/j.molcel.2020.12.041] [Citation(s) in RCA: 180] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 11/06/2020] [Accepted: 12/21/2020] [Indexed: 02/07/2023]
Abstract
Severe-acute-respiratory-syndrome-related coronavirus 2 (SARS-CoV-2) is the positive-sense RNA virus that causes coronavirus disease 2019 (COVID-19). The genome of SARS-CoV-2 is unique among viral RNAs in its vast potential to form RNA structures, yet as much as 97% of its 30 kilobases have not been structurally explored. Here, we apply a novel long amplicon strategy to determine the secondary structure of the SARS-CoV-2 RNA genome at single-nucleotide resolution in infected cells. Our in-depth structural analysis reveals networks of well-folded RNA structures throughout Orf1ab and reveals aspects of SARS-CoV-2 genome architecture that distinguish it from other RNA viruses. Evolutionary analysis shows that several features of the SARS-CoV-2 genomic structure are conserved across β-coronaviruses, and we pinpoint regions of well-folded RNA structure that merit downstream functional analysis. The native, secondary structure of SARS-CoV-2 presented here is a roadmap that will facilitate focused studies on the viral life cycle, facilitate primer design, and guide the identification of RNA drug targets against COVID-19.
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Affiliation(s)
- Nicholas C Huston
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06511, USA
| | - Han Wan
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Madison S Strine
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Immunobiology, Yale School of Medicine, New Haven, CT 06519, USA
| | | | - Craig B Wilen
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT 06510, USA; Department of Immunobiology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Anna Marie Pyle
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06511, USA; Department of Chemistry, Yale University, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
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30
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Coronavirus replication-transcription complex: Vital and selective NMPylation of a conserved site in nsp9 by the NiRAN-RdRp subunit. Proc Natl Acad Sci U S A 2021; 118:2022310118. [PMID: 33472860 PMCID: PMC8017715 DOI: 10.1073/pnas.2022310118] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
RNA-dependent RNA polymerases (RdRps) of the Nidovirales (Coronaviridae, Arteriviridae, and 12 other families) are linked to an amino-terminal (N-terminal) domain, called NiRAN, in a nonstructural protein (nsp) that is released from polyprotein 1ab by the viral main protease (Mpro). Previously, self-GMPylation/UMPylation activities were reported for an arterivirus NiRAN-RdRp nsp and suggested to generate a transient state primed for transferring nucleoside monophosphate (NMP) to (currently unknown) viral and/or cellular biopolymers. Here, we show that the coronavirus (human coronavirus [HCoV]-229E and severe acute respiratory syndrome coronavirus 2) nsp12 (NiRAN-RdRp) has Mn2+-dependent NMPylation activity that catalyzes the transfer of a single NMP to the cognate nsp9 by forming a phosphoramidate bond with the primary amine at the nsp9 N terminus (N3825) following Mpro-mediated proteolytic release of nsp9 from N-terminally flanking nsps. Uridine triphosphate was the preferred nucleotide in this reaction, but also adenosine triphosphate, guanosine triphosphate, and cytidine triphosphate were suitable cosubstrates. Mutational studies using recombinant coronavirus nsp9 and nsp12 proteins and genetically engineered HCoV-229E mutants identified residues essential for NiRAN-mediated nsp9 NMPylation and virus replication in cell culture. The data corroborate predictions on NiRAN active-site residues and establish an essential role for the nsp9 N3826 residue in both nsp9 NMPylation in vitro and virus replication. This residue is part of a conserved N-terminal NNE tripeptide sequence and shown to be the only invariant residue in nsp9 and its homologs in viruses of the family Coronaviridae The study provides a solid basis for functional studies of other nidovirus NMPylation activities and suggests a possible target for antiviral drug development.
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31
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Zhao J, Qiu J, Aryal S, Hackett JL, Wang J. The RNA Architecture of the SARS-CoV-2 3'-Untranslated Region. Viruses 2020; 12:E1473. [PMID: 33371200 PMCID: PMC7766253 DOI: 10.3390/v12121473] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/11/2020] [Accepted: 12/15/2020] [Indexed: 11/16/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the current COVID-19 pandemic. The 3' untranslated region (UTR) of this β-CoV contains essential cis-acting RNA elements for the viral genome transcription and replication. These elements include an equilibrium between an extended bulged stem-loop (BSL) and a pseudoknot. The existence of such an equilibrium is supported by reverse genetic studies and phylogenetic covariation analysis and is further proposed as a molecular switch essential for the control of the viral RNA polymerase binding. Here, we report the SARS-CoV-2 3' UTR structures in cells that transcribe the viral UTRs harbored in a minigene plasmid and isolated infectious virions using a chemical probing technique, namely dimethyl sulfate (DMS)-mutational profiling with sequencing (MaPseq). Interestingly, the putative pseudoknotted conformation was not observed, indicating that its abundance in our systems is low in the absence of the viral nonstructural proteins (nsps). Similarly, our results also suggest that another functional cis-acting element, the three-helix junction, cannot stably form. The overall architectures of the viral 3' UTRs in the infectious virions and the minigene-transfected cells are almost identical.
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Affiliation(s)
- Junxing Zhao
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA; (J.Z.); (S.A.)
| | - Jianming Qiu
- Department of Microbiology, Molecular Genetics & Immunology, University of Kansas Medical Center, Kansas, KS 66160, USA;
| | - Sadikshya Aryal
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA; (J.Z.); (S.A.)
| | | | - Jingxin Wang
- Department of Medicinal Chemistry, University of Kansas, Lawrence, KS 66047, USA; (J.Z.); (S.A.)
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Wacker A, Weigand JE, Akabayov SR, Altincekic N, Bains JK, Banijamali E, Binas O, Castillo-Martinez J, Cetiner E, Ceylan B, Chiu LY, Davila-Calderon J, Dhamotharan K, Duchardt-Ferner E, Ferner J, Frydman L, Fürtig B, Gallego J, Grün JT, Hacker C, Haddad C, Hähnke M, Hengesbach M, Hiller F, Hohmann KF, Hymon D, de Jesus V, Jonker H, Keller H, Knezic B, Landgraf T, Löhr F, Luo L, Mertinkus KR, Muhs C, Novakovic M, Oxenfarth A, Palomino-Schätzlein M, Petzold K, Peter SA, Pyper DJ, Qureshi NS, Riad M, Richter C, Saxena K, Schamber T, Scherf T, Schlagnitweit J, Schlundt A, Schnieders R, Schwalbe H, Simba-Lahuasi A, Sreeramulu S, Stirnal E, Sudakov A, Tants JN, Tolbert BS, Vögele J, Weiß L, Wirmer-Bartoschek J, Wirtz Martin MA, Wöhnert J, Zetzsche H. Secondary structure determination of conserved SARS-CoV-2 RNA elements by NMR spectroscopy. Nucleic Acids Res 2020; 48:12415-12435. [PMID: 33167030 PMCID: PMC7736788 DOI: 10.1093/nar/gkaa1013] [Citation(s) in RCA: 111] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/08/2020] [Accepted: 10/14/2020] [Indexed: 12/24/2022] Open
Abstract
The current pandemic situation caused by the Betacoronavirus SARS-CoV-2 (SCoV2) highlights the need for coordinated research to combat COVID-19. A particularly important aspect is the development of medication. In addition to viral proteins, structured RNA elements represent a potent alternative as drug targets. The search for drugs that target RNA requires their high-resolution structural characterization. Using nuclear magnetic resonance (NMR) spectroscopy, a worldwide consortium of NMR researchers aims to characterize potential RNA drug targets of SCoV2. Here, we report the characterization of 15 conserved RNA elements located at the 5' end, the ribosomal frameshift segment and the 3'-untranslated region (3'-UTR) of the SCoV2 genome, their large-scale production and NMR-based secondary structure determination. The NMR data are corroborated with secondary structure probing by DMS footprinting experiments. The close agreement of NMR secondary structure determination of isolated RNA elements with DMS footprinting and NMR performed on larger RNA regions shows that the secondary structure elements fold independently. The NMR data reported here provide the basis for NMR investigations of RNA function, RNA interactions with viral and host proteins and screening campaigns to identify potential RNA binders for pharmaceutical intervention.
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Affiliation(s)
- Anna Wacker
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Julia E Weigand
- Department of Biology, Technical University of Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Sabine R Akabayov
- Faculty of Chemistry, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Nadide Altincekic
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Jasleen Kaur Bains
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Elnaz Banijamali
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Biomedicum 9B, Solnavägen 9, 17177 Stockholm, Sweden
| | - Oliver Binas
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | | | - Erhan Cetiner
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Betül Ceylan
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Liang-Yuan Chiu
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | | | - Jan Ferner
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Lucio Frydman
- Faculty of Chemistry, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Boris Fürtig
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - José Gallego
- School of Medicine, Catholic University of Valencia, C/Quevedo 2, 46001 Valencia, Spain
| | - J Tassilo Grün
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Carolin Hacker
- Signals GmbH & Co. KG, Graf-von-Stauffenberg-Allee 83, 60438 Frankfurt/M, Germany
| | - Christina Haddad
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Martin Hähnke
- Signals GmbH & Co. KG, Graf-von-Stauffenberg-Allee 83, 60438 Frankfurt/M, Germany
| | - Martin Hengesbach
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Fabian Hiller
- Signals GmbH & Co. KG, Graf-von-Stauffenberg-Allee 83, 60438 Frankfurt/M, Germany
| | - Katharina F Hohmann
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Daniel Hymon
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Vanessa de Jesus
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Henry Jonker
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | | | - Bozana Knezic
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Tom Landgraf
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Frank Löhr
- Institute of Biophysical Chemistry, Center for Biomolecular Magnetic Resonance (BMRZ), Johann Wolfgang Goethe-University Frankfurt, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Le Luo
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Biomedicum 9B, Solnavägen 9, 17177 Stockholm, Sweden
| | - Klara R Mertinkus
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Christina Muhs
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Mihajlo Novakovic
- Faculty of Chemistry, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Andreas Oxenfarth
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | | | - Katja Petzold
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Biomedicum 9B, Solnavägen 9, 17177 Stockholm, Sweden
| | - Stephen A Peter
- Department of Biology, Technical University of Darmstadt, Schnittspahnstrasse 10, 64287 Darmstadt, Germany
| | - Dennis J Pyper
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Nusrat S Qureshi
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Magdalena Riad
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Biomedicum 9B, Solnavägen 9, 17177 Stockholm, Sweden
| | - Christian Richter
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Krishna Saxena
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Tatjana Schamber
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Tali Scherf
- Faculty of Chemistry, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Judith Schlagnitweit
- Department of Medical Biochemistry and Biophysics, Karolinska Institute, Biomedicum 9B, Solnavägen 9, 17177 Stockholm, Sweden
| | | | - Robbin Schnieders
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Alvaro Simba-Lahuasi
- School of Medicine, Catholic University of Valencia, C/Quevedo 2, 46001 Valencia, Spain
| | - Sridhar Sreeramulu
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Elke Stirnal
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Alexey Sudakov
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | | | - Blanton S Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | - Julia Wirmer-Bartoschek
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | - Maria A Wirtz Martin
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
| | | | - Heidi Zetzsche
- Institute for Organic Chemistry and Chemical Biology, Max-von-Laue-Strasse 7, 60438 Frankfurt/M., Germany
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de Breyne S, Vindry C, Guillin O, Condé L, Mure F, Gruffat H, Chavatte L, Ohlmann T. Translational control of coronaviruses. Nucleic Acids Res 2020; 48:12502-12522. [PMID: 33264393 PMCID: PMC7736815 DOI: 10.1093/nar/gkaa1116] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/29/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022] Open
Abstract
Coronaviruses represent a large family of enveloped RNA viruses that infect a large spectrum of animals. In humans, the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is responsible for the current COVID-19 pandemic and is genetically related to SARS-CoV and Middle East respiratory syndrome-related coronavirus (MERS-CoV), which caused outbreaks in 2002 and 2012, respectively. All viruses described to date entirely rely on the protein synthesis machinery of the host cells to produce proteins required for their replication and spread. As such, virus often need to control the cellular translational apparatus to avoid the first line of the cellular defense intended to limit the viral propagation. Thus, coronaviruses have developed remarkable strategies to hijack the host translational machinery in order to favor viral protein production. In this review, we will describe some of these strategies and will highlight the role of viral proteins and RNAs in this process.
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Affiliation(s)
- Sylvain de Breyne
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Caroline Vindry
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Olivia Guillin
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Lionel Condé
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Fabrice Mure
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Henri Gruffat
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Laurent Chavatte
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
| | - Théophile Ohlmann
- CIRI, Centre International de Recherche en Infectiologie, Univ Lyon, INSERM U1111, Université Claude Bernard Lyon 1, CNRS UMR5308, ENS de Lyon, F-69007, Lyon, France
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34
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Ancar R, Li Y, Kindler E, Cooper DA, Ransom M, Thiel V, Weiss SR, Hesselberth JR, Barton DJ. Physiologic RNA targets and refined sequence specificity of coronavirus EndoU. RNA (NEW YORK, N.Y.) 2020; 26:1976-1999. [PMID: 32989044 PMCID: PMC7668261 DOI: 10.1261/rna.076604.120] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 09/12/2020] [Indexed: 05/15/2023]
Abstract
Coronavirus EndoU inhibits dsRNA-activated antiviral responses; however, the physiologic RNA substrates of EndoU are unknown. In this study, we used mouse hepatitis virus (MHV)-infected bone marrow-derived macrophage (BMM) and cyclic phosphate cDNA sequencing to identify the RNA targets of EndoU. EndoU targeted viral RNA, cleaving the 3' side of pyrimidines with a strong preference for U ↓ A and C ↓ A sequences (endoY ↓ A). EndoU-dependent cleavage was detected in every region of MHV RNA, from the 5' NTR to the 3' NTR, including transcriptional regulatory sequences (TRS). Cleavage at two CA dinucleotides immediately adjacent to the MHV poly(A) tail suggests a mechanism to suppress negative-strand RNA synthesis and the accumulation of viral dsRNA. MHV with EndoU (EndoUmut) or 2'-5' phosphodiesterase (PDEmut) mutations provoked the activation of RNase L in BMM, with corresponding cleavage of RNAs by RNase L. The physiologic targets of EndoU are viral RNA templates required for negative-strand RNA synthesis and dsRNA accumulation. Coronavirus EndoU cleaves U ↓ A and C ↓ A sequences (endoY ↓ A) within viral (+) strand RNA to evade dsRNA-activated host responses.
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Affiliation(s)
- Rachel Ancar
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora 80045, Colorado, USA
| | - Yize Li
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Eveline Kindler
- Institute of Virology and Immunology IVI, 3001 Bern and 3147 Mittelhausern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - Daphne A Cooper
- Department of Immunology and Microbiology, School of Medicine, University of Colorado, Aurora, Colorado 80045, USA
| | - Monica Ransom
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora 80045, Colorado, USA
| | - Volker Thiel
- Institute of Virology and Immunology IVI, 3001 Bern and 3147 Mittelhausern, Switzerland
- Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland
| | - Susan R Weiss
- Department of Microbiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Jay R Hesselberth
- Department of Biochemistry and Molecular Genetics, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora 80045, Colorado, USA
| | - David J Barton
- Department of Immunology and Microbiology, Program in Molecular Biology, School of Medicine, University of Colorado, Aurora, Colorado 80045, USA
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35
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McNamara RP, Caro-Vegas C, Landis JT, Moorad R, Pluta LJ, Eason AB, Thompson C, Bailey A, Villamor FCS, Lange PT, Wong JP, Seltzer T, Seltzer J, Zhou Y, Vahrson W, Juarez A, Meyo JO, Calabre T, Broussard G, Rivera-Soto R, Chappell DL, Baric RS, Damania B, Miller MB, Dittmer DP. High-Density Amplicon Sequencing Identifies Community Spread and Ongoing Evolution of SARS-CoV-2 in the Southern United States. Cell Rep 2020; 33:108352. [PMID: 33113345 PMCID: PMC7574689 DOI: 10.1016/j.celrep.2020.108352] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/04/2020] [Accepted: 10/14/2020] [Indexed: 12/13/2022] Open
Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is constantly evolving. Prior studies focused on high-case-density locations, such as the northern and western metropolitan areas of the United States. This study demonstrates continued SARS-CoV-2 evolution in a suburban southern region of the United States by high-density amplicon sequencing of symptomatic cases. 57% of strains carry the spike D614G variant, which is associated with higher genome copy numbers, and its prevalence expands with time. Four strains carry a deletion in a predicted stem loop of the 3' UTR. The data are consistent with community spread within local populations and the larger continental United States. The data instill confidence in current testing sensitivity and validate "testing by sequencing" as an option to uncover cases, particularly nonstandard coronavirus disease 2019 (COVID-19) clinical presentations. This study contributes to the understanding of COVID-19 through an extensive set of genomes from a non-urban setting and informs vaccine design by defining D614G as a dominant and emergent SARS-CoV-2 isolate in the United States.
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Affiliation(s)
- Ryan P McNamara
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Carolina Caro-Vegas
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Justin T Landis
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Razia Moorad
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Linda J Pluta
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Anthony B Eason
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Cecilia Thompson
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Clinical Microbiology Laboratory, UNC Medical Center, Chapel Hill, NC 27599, USA
| | - Aubrey Bailey
- Kuopio Center for Gene and Cell Therapy, Kuopio, Finland
| | - Femi Cleola S Villamor
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Philip T Lange
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Jason P Wong
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Tischan Seltzer
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Jedediah Seltzer
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Yijun Zhou
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | | | - Angelica Juarez
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - James O Meyo
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Genetics Curriculum, Chapel Hill, NC 27599, USA
| | - Tiphaine Calabre
- École supérieure de Chimie Physique Électronique (CPE), Lyon, France
| | - Grant Broussard
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Genetics Curriculum, Chapel Hill, NC 27599, USA
| | - Ricardo Rivera-Soto
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Genetics Curriculum, Chapel Hill, NC 27599, USA
| | - Danielle L Chappell
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ralph S Baric
- Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA; Department of Epidemiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Blossom Damania
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA
| | - Melissa B Miller
- Department of Pathology and Laboratory Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Clinical Microbiology Laboratory, UNC Medical Center, Chapel Hill, NC 27599, USA.
| | - Dirk P Dittmer
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, NC 27599, USA; Lineberger Comprehensive Cancer Center, Chapel Hill, NC 27599, USA.
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36
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Keep S, Oade MS, Lidzbarski-Silvestre F, Bentley K, Stevenson-Leggett P, Freimanis GL, Tennakoon C, Sanderson N, Hammond JA, Jones RC, Britton P, Bickerton E. Multiple novel non-canonically transcribed sub-genomic mRNAs produced by avian coronavirus infectious bronchitis virus. J Gen Virol 2020; 101:1103-1118. [PMID: 32720890 PMCID: PMC7660457 DOI: 10.1099/jgv.0.001474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 07/01/2020] [Indexed: 12/15/2022] Open
Abstract
Coronavirus sub-genomic mRNA (sgmRNA) synthesis occurs via a process of discontinuous transcription involving complementary transcription regulatory sequences (TRSs), one (TRS-L) encompassing the leader sequence of the 5' untranslated region (UTR), and the other upstream of each structural and accessory gene (TRS-B). Several coronaviruses have an ORF located between the N gene and the 3'-UTR, an area previously thought to be non-coding in the Gammacoronavirus infectious bronchitis virus (IBV) due to a lack of a canonical TRS-B. Here, we identify a non-canonical TRS-B allowing for a novel sgmRNA relating to this ORF to be produced in several strains of IBV: Beaudette, CR88, H120, D1466, Italy-02 and QX. Interestingly, the potential protein produced by this ORF is prematurely truncated in the Beaudette strain. A single nucleotide deletion was made in the Beaudette strain allowing for the generation of a recombinant IBV (rIBV) that had the potential to express a full-length protein. Assessment of this rIBV in vitro demonstrated that restoration of the full-length potential protein had no effect on viral replication. Further assessment of the Beaudette-derived RNA identified a second non-canonically transcribed sgmRNA located within gene 2. Deep sequencing analysis of allantoic fluid from Beaudette-infected embryonated eggs confirmed the presence of both the newly identified non-canonically transcribed sgmRNAs and highlighted the potential for further yet unidentified sgmRNAs. This HiSeq data, alongside the confirmation of non-canonically transcribed sgmRNAs, indicates the potential of the coronavirus genome to encode a larger repertoire of genes than has currently been identified.
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Affiliation(s)
- Sarah Keep
- The Pirbright Institute, Ash Road, Woking, GU24 0NF, UK
| | | | - Filip Lidzbarski-Silvestre
- The Pirbright Institute, Ash Road, Woking, GU24 0NF, UK
- School of Biosciences, Cardiff University, Cardiff, UK
| | - Kirsten Bentley
- The Pirbright Institute, Ash Road, Woking, GU24 0NF, UK
- School of Biology, University of St Andrews, St Andrews, UK
| | | | | | | | - Nicholas Sanderson
- The Pirbright Institute, Ash Road, Woking, GU24 0NF, UK
- Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Richard C. Jones
- School of Veterinary Science, University of Liverpool, Neston, UK
| | - Paul Britton
- The Pirbright Institute, Ash Road, Woking, GU24 0NF, UK
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37
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Huston NC, Wan H, de Cesaris Araujo Tavares R, Wilen C, Pyle AM. Comprehensive in-vivo secondary structure of the SARS-CoV-2 genome reveals novel regulatory motifs and mechanisms. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.07.10.197079. [PMID: 32676598 PMCID: PMC7359520 DOI: 10.1101/2020.07.10.197079] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
SARS-CoV-2 is the positive-sense RNA virus that causes COVID-19, a disease that has triggered a major human health and economic crisis. The genome of SARS-CoV-2 is unique among viral RNAs in its vast potential to form stable RNA structures and yet, as much as 97% of its 30 kilobases have not been structurally explored in the context of a viral infection. Our limited knowledge of SARS-CoV-2 genomic architecture is a fundamental limitation to both our mechanistic understanding of coronavirus life cycle and the development of COVID-19 RNA-based therapeutics. Here, we apply a novel long amplicon strategy to determine for the first time the secondary structure of the SARS-CoV-2 RNA genome probed in infected cells. In addition to the conserved structural motifs at the viral termini, we report new structural features like a conformationally flexible programmed ribosomal frameshifting pseudoknot, and a host of novel RNA structures, each of which highlights the importance of studying viral structures in their native genomic context. Our in-depth structural analysis reveals extensive networks of well-folded RNA structures throughout Orf1ab and reveals new aspects of SARS-CoV-2 genome architecture that distinguish it from other single-stranded, positive-sense RNA viruses. Evolutionary analysis of RNA structures in SARS-CoV-2 shows that several features of its genomic structure are conserved across beta coronaviruses and we pinpoint individual regions of well-folded RNA structure that merit downstream functional analysis. The native, complete secondary structure of SAR-CoV-2 presented here is a roadmap that will facilitate focused studies on mechanisms of replication, translation and packaging, and guide the identification of new RNA drug targets against COVID-19.
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Affiliation(s)
- Nicholas C. Huston
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Han Wan
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT, USA
| | | | - Craig Wilen
- Department of Laboratory Medicine, Yale School of Medicine, New Haven, CT, USA
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
| | - Anna Marie Pyle
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT, USA
- Department of Chemistry, Yale University, New Haven, CT, USA
- Howard Hughes Medical Institute, Chevy Chase, MD, USA
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Ryder SP, Morgan BR, Massi F. Analysis of Rapidly Emerging Variants in Structured Regions of the SARS-CoV-2 Genome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020. [PMID: 32577650 DOI: 10.1101/2020.05.27.120105] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has motivated a widespread effort to understand its epidemiology and pathogenic mechanisms. Modern high-throughput sequencing technology has led to the deposition of vast numbers of SARS-CoV-2 genome sequences in curated repositories, which have been useful in mapping the spread of the virus around the globe. They also provide a unique opportunity to observe virus evolution in real time. Here, we evaluate two cohorts of SARS-CoV-2 genomic sequences to identify rapidly emerging variants within structured cis-regulatory elements of the SARS-CoV-2 genome. Overall, twenty variants are present at a minor allele frequency of at least 0.5%. Several enhance the stability of Stem Loop 1 in the 5'UTR, including a set of co-occurring variants that extend its length. One appears to modulate the stability of the frameshifting pseudoknot between ORF1a and ORF1b, and another perturbs a bi-stable molecular switch in the 3'UTR. Finally, five variants destabilize structured elements within the 3'UTR hypervariable region, including the S2M stem loop, raising questions as to the functional relevance of these structures in viral replication. Two of the most abundant variants appear to be caused by RNA editing, suggesting host-viral defense contributes to SARS-CoV-2 genome heterogeneity. This analysis has implications for the development of therapeutics that target viral cis-regulatory RNA structures or sequences, as rapidly emerging variations in these regions could lead to drug resistance.
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Lo CY, Tsai TL, Lin CN, Lin CH, Wu HY. Interaction of coronavirus nucleocapsid protein with the 5'- and 3'-ends of the coronavirus genome is involved in genome circularization and negative-strand RNA synthesis. FEBS J 2019; 286:3222-3239. [PMID: 31034708 PMCID: PMC7164124 DOI: 10.1111/febs.14863] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 03/21/2019] [Accepted: 04/25/2019] [Indexed: 12/28/2022]
Abstract
Synthesis of the negative‐strand ((−)‐strand) counterpart is the first step of coronavirus (CoV) replication; however, the detailed mechanism of the early event and the factors involved remain to be determined. Here, using bovine coronavirus (BCoV)‐defective interfering (DI) RNA, we showed that (a) a poly(A) tail with a length of 15 nucleotides (nt) was sufficient to initiate efficient (−)‐strand RNA synthesis and (b) substitution of the poly(A) tail with poly(U), (C) or (G) only slightly decreased the efficiency of (−)‐strand synthesis. The findings indicate that in addition to the poly(A) tail, other factors acting in trans may also participate in (−)‐strand synthesis. The BCoV nucleocapsid (N) protein, an RNA‐binding protein, was therefore tested as a candidate. Based on dissociation constant (Kd) values, it was found that the binding affinity between N protein, but not poly(A)‐binding protein, and the 3′‐terminal 55 nt plus a poly(A), poly(U), poly(C) or poly(G) tail correlates with the efficiency of (−)‐strand synthesis. Such an association was also evidenced by the binding affinity between the N protein and 5′‐ and 3′‐terminal cis‐acting elements important for (−)‐strand synthesis. Further analysis demonstrated that N protein can act as a bridge to facilitate interaction between the 5′‐ and 3′‐ends of the CoV genome, leading to circularization of the genome. Together, the current study extends our understanding of the mechanism of CoV (−)‐strand RNA synthesis through involvement of N protein and genome circularization and thus may explain why the addition of N protein in trans is required for efficient CoV replication.
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Affiliation(s)
- Chen-Yu Lo
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Tsung-Lin Tsai
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Chao-Nan Lin
- Department of Veterinary Medicine, National Pingtung University of Science and Technology, Neipu, Pingtung, Taiwan
| | - Ching-Hung Lin
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Hung-Yi Wu
- Graduate Institute of Veterinary Pathobiology, College of Veterinary Medicine, National Chung Hsing University, Taichung, Taiwan
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Interplay between the Poly(A) Tail, Poly(A)-Binding Protein, and Coronavirus Nucleocapsid Protein Regulates Gene Expression of Coronavirus and the Host Cell. J Virol 2018; 92:JVI.01162-18. [PMID: 30209168 DOI: 10.1128/jvi.01162-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 08/30/2018] [Indexed: 12/26/2022] Open
Abstract
In the present study, we investigated the roles of interactions among the poly(A) tail, coronavirus nucleocapsid (N) protein, and poly(A)-binding protein (PABP) in the regulation of coronavirus gene expression. Through dissociation constant (Kd ) comparison, we found that the coronavirus N protein can bind to the poly(A) tail with high affinity, establishing N protein as a PABP. A subsequent analysis with UV cross-linking and immunoprecipitation revealed that the N protein is able to bind to the poly(A) tail in infected cells. Further examination demonstrated that poly(A) tail binding by the N protein negatively regulates translation of coronaviral RNA and host mRNA both in vitro and in cells. Although the N protein can interact with PABP and eukaryotic initiation factor 4G (eIF4G), the poor interaction efficiency between the poly(A)-bound N protein and eIF4E may explain the observed decreased translation efficiency. In addition to interaction with translation factor eIF4G, the N protein is able to interact with coronavirus nonstructural protein 9 (nsp9), a replicase protein required for replication. The study demonstrates interactions among the poly(A) tail, N protein, and PABP both in vitro and in infected cells. Of the interactions, binding of the poly(A) tail to N protein decreases the interaction efficiency between the poly(A) tail and eIF4E, leading to translation inhibition. The poly(A)-dependent translation inhibition by N protein has not been previously demonstrated and thus extends our understanding of coronavirus gene expression.IMPORTANCE Gene expression in coronavirus is a complicated and dynamic process. In this study, we demonstrated that coronavirus N protein is able to bind to the poly(A) tail with high affinity, establishing N protein as a PABP. We also show how the interplay between coronavirus 3' poly(A) tail, PABP, and N protein regulates gene expression of the coronavirus and host cell. Of the interactions, poly(A) tail binding by the N protein negatively regulates translation, and to our knowledge, this inhibition of translation by binding of the N protein to poly(A) tail has not been previously studied. Accordingly, the study provides fundamental molecular details regarding coronavirus infection and expands our knowledge of coronavirus gene expression.
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Abstract
Reproduction of RNA viruses is typically error-prone due to the infidelity of their replicative machinery and the usual lack of proofreading mechanisms. The error rates may be close to those that kill the virus. Consequently, populations of RNA viruses are represented by heterogeneous sets of genomes with various levels of fitness. This is especially consequential when viruses encounter various bottlenecks and new infections are initiated by a single or few deviating genomes. Nevertheless, RNA viruses are able to maintain their identity by conservation of major functional elements. This conservatism stems from genetic robustness or mutational tolerance, which is largely due to the functional degeneracy of many protein and RNA elements as well as to negative selection. Another relevant mechanism is the capacity to restore fitness after genetic damages, also based on replicative infidelity. Conversely, error-prone replication is a major tool that ensures viral evolvability. The potential for changes in debilitated genomes is much higher in small populations, because in the absence of stronger competitors low-fit genomes have a choice of various trajectories to wander along fitness landscapes. Thus, low-fit populations are inherently unstable, and it may be said that to run ahead it is useful to stumble. In this report, focusing on picornaviruses and also considering data from other RNA viruses, we review the biological relevance and mechanisms of various alterations of viral RNA genomes as well as pathways and mechanisms of rehabilitation after loss of fitness. The relationships among mutational robustness, resilience, and evolvability of viral RNA genomes are discussed.
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Charley PA, Wilusz CJ, Wilusz J. Identification of phlebovirus and arenavirus RNA sequences that stall and repress the exoribonuclease XRN1. J Biol Chem 2017; 293:285-295. [PMID: 29118186 DOI: 10.1074/jbc.m117.805796] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/06/2017] [Indexed: 12/22/2022] Open
Abstract
Regulated mRNA decay plays a vital role in determining both the level and quality of cellular gene expression. Viral RNAs must successfully evade this host RNA decay machinery to establish a productive infection. One way for RNA viruses to accomplish this is to target the cellular exoribonuclease XRN1, because this enzyme is accessible in the cytoplasm and plays a major role in mRNA decay. Members of the Flaviviridae use RNA structures in their 5'- or 3'-untranslated regions to stall and repress XRN1, effectively stabilizing viral RNAs while also causing significant dysregulation of host cell mRNA stability. Here, we use a series of biochemical assays to demonstrate that the 3'-terminal portion of the nucleocapsid (N) mRNA of Rift Valley fever virus, a phlebovirus of the Bunyaviridae family, also can effectively stall and repress XRN1. The region responsible for impeding XRN1 includes a G-rich portion that likely forms a G-quadruplex structure. The 3'-terminal portions of ambisense-derived transcripts of multiple arenaviruses also stalled XRN1. Therefore, we conclude that RNAs from two additional families of mammalian RNA viruses stall and repress XRN1. This observation. emphasizes the importance and commonality of this viral strategy to interfere with the 5'-to-3'-exoribonuclease component of the cytoplasmic RNA decay machinery.
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Affiliation(s)
- Phillida A Charley
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Carol J Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523
| | - Jeffrey Wilusz
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado 80523.
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Hu T, Chen C, Li H, Dou Y, Zhou M, Lu D, Zong Q, Li Y, Yang C, Zhong Z, Singh N, Hu H, Zhang R, Yang H, Su D. Structural basis for dimerization and RNA binding of avian infectious bronchitis virus nsp9. Protein Sci 2017; 26:1037-1048. [PMID: 28257598 PMCID: PMC5405427 DOI: 10.1002/pro.3150] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/28/2017] [Accepted: 02/28/2017] [Indexed: 02/05/2023]
Abstract
The potential for infection by coronaviruses (CoVs) has become a serious concern with the recent emergence of Middle East respiratory syndrome and severe acute respiratory syndrome (SARS) in the human population. CoVs encode two large polyproteins, which are then processed into 15–16 nonstructural proteins (nsps) that make significant contributions to viral replication and transcription by assembling the RNA replicase complex. Among them, nsp9 plays an essential role in viral replication by forming a homodimer that binds single‐stranded RNA. Thus, disrupting nsp9 dimerization is a potential anti‐CoV therapy. However, different nsp9 dimer forms have been reported for alpha‐ and beta‐CoVs, and no structural information is available for gamma‐CoVs. Here we determined the crystal structure of nsp9 from the avian infectious bronchitis virus (IBV), a representative gamma‐CoV that affects the economy of the poultry industry because it can infect domestic fowl. IBV nsp9 forms a homodimer via interactions across a hydrophobic interface, which consists of two parallel alpha helices near the carboxy terminus of the protein. The IBV nsp9 dimer resembles that of SARS‐CoV nsp9, indicating that this type of dimerization is conserved among all CoVs. This makes disruption of the dimeric interface an excellent strategy for developing anti‐CoV therapies. To facilitate this effort, we characterized the roles of six conserved residues on this interface using site‐directed mutagenesis and a multitude of biochemical and biophysical methods. We found that three residues are critical for nsp9 dimerization and its abitlity to bind RNA. PDB Code(s): 5C94
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Affiliation(s)
- Tingting Hu
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
| | - Cheng Chen
- School of Life Sciences, Tianjin University, Tianjin, 300072, P.R. China
| | - Huiyan Li
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
| | - Yanshu Dou
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
| | - Ming Zhou
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
| | - Deren Lu
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
| | - Qi Zong
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
| | - Yulei Li
- Department of Organic Chemistry, School of Pharmacy, Second Military Medical University, Shanghai, 200433, P.R. China
| | - Cheng Yang
- College of Chemistry, Sichuan University, Chengdu, 610041, P.R. China
| | - Zhihui Zhong
- Laboratory of Non-human Primate Disease Modeling Research, West China Hospital, Sichuan University, Chengdu, 610041, P.R. China
| | - Namit Singh
- Ludwig Institute for Cancer Research, University of California, La Jolla, San Diego, California, 92093, USA
| | - Honggang Hu
- Department of Organic Chemistry, School of Pharmacy, Second Military Medical University, Shanghai, 200433, P.R. China
| | - Rundong Zhang
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China.,Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu, 610041, P.R. China
| | - Haitao Yang
- School of Life Sciences, Tianjin University, Tianjin, 300072, P.R. China
| | - Dan Su
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, 610041, P.R. China
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Posthuma CC, Te Velthuis AJW, Snijder EJ. Nidovirus RNA polymerases: Complex enzymes handling exceptional RNA genomes. Virus Res 2017; 234:58-73. [PMID: 28174054 PMCID: PMC7114556 DOI: 10.1016/j.virusres.2017.01.023] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 01/24/2017] [Accepted: 01/26/2017] [Indexed: 12/22/2022]
Abstract
Coronaviruses and arteriviruses are distantly related human and animal pathogens that belong to the order Nidovirales. Nidoviruses are characterized by their polycistronic plus-stranded RNA genome, the production of subgenomic mRNAs and the conservation of a specific array of replicase domains, including key RNA-synthesizing enzymes. Coronaviruses (26-34 kilobases) have the largest known RNA genomes and their replication presumably requires a processive RNA-dependent RNA polymerase (RdRp) and enzymatic functions that suppress the consequences of the typically high error rate of viral RdRps. The arteriviruses have significantly smaller genomes and form an intriguing package with the coronaviruses to analyse viral RdRp evolution and function. The RdRp domain of nidoviruses resides in a cleavage product of the replicase polyprotein named non-structural protein (nsp) 12 in coronaviruses and nsp9 in arteriviruses. In all nidoviruses, the C-terminal RdRp domain is linked to a conserved N-terminal domain, which has been coined NiRAN (nidovirus RdRp-associated nucleotidyl transferase). Although no structural information is available, the functional characterization of the nidovirus RdRp and the larger enzyme complex of which it is part, has progressed significantly over the past decade. In coronaviruses several smaller, non-enzymatic nsps were characterized that direct RdRp function, while a 3'-to-5' exoribonuclease activity in nsp14 was implicated in fidelity. In arteriviruses, the nsp1 subunit was found to maintain the balance between genome replication and subgenomic mRNA production. Understanding RdRp behaviour and interactions during RNA synthesis and subsequent processing will be key to rationalising the evolutionary success of nidoviruses and the development of antiviral strategies.
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Affiliation(s)
- Clara C Posthuma
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands.
| | - Aartjan J W Te Velthuis
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, United Kingdom; Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - Eric J Snijder
- Molecular Virology Laboratory, Department of Medical Microbiology, Leiden University Medical Center, Leiden, the Netherlands
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Characterization of the Role of Hexamer AGUAAA and Poly(A) Tail in Coronavirus Polyadenylation. PLoS One 2016; 11:e0165077. [PMID: 27760233 PMCID: PMC5070815 DOI: 10.1371/journal.pone.0165077] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Accepted: 10/05/2016] [Indexed: 01/21/2023] Open
Abstract
Similar to eukaryotic mRNA, the positive-strand coronavirus genome of ~30 kilobases is 5’-capped and 3’-polyadenylated. It has been demonstrated that the length of the coronaviral poly(A) tail is not static but regulated during infection; however, little is known regarding the factors involved in coronaviral polyadenylation and its regulation. Here, we show that during infection, the level of coronavirus poly(A) tail lengthening depends on the initial length upon infection and that the minimum length to initiate lengthening may lie between 5 and 9 nucleotides. By mutagenesis analysis, it was found that (i) the hexamer AGUAAA and poly(A) tail are two important elements responsible for synthesis of the coronavirus poly(A) tail and may function in concert to accomplish polyadenylation and (ii) the function of the hexamer AGUAAA in coronaviral polyadenylation is position dependent. Based on these findings, we propose a process for how the coronaviral poly(A) tail is synthesized and undergoes variation. Our results provide the first genetic evidence to gain insight into coronaviral polyadenylation.
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Abstract
Coronaviruses are animal and human pathogens that can cause lethal zoonotic infections like SARS and MERS. They have polycistronic plus-stranded RNA genomes and belong to the order Nidovirales, a diverse group of viruses for which common ancestry was inferred from the common principles underlying their genome organization and expression, and from the conservation of an array of core replicase domains, including key RNA-synthesizing enzymes. Coronavirus genomes (~ 26–32 kilobases) are the largest RNA genomes known to date and their expansion was likely enabled by acquiring enzyme functions that counter the commonly high error frequency of viral RNA polymerases. The primary functions that direct coronavirus RNA synthesis and processing reside in nonstructural protein (nsp) 7 to nsp16, which are cleavage products of two large replicase polyproteins translated from the coronavirus genome. Significant progress has now been made regarding their structural and functional characterization, stimulated by technical advances like improved methods for bioinformatics and structural biology, in vitro enzyme characterization, and site-directed mutagenesis of coronavirus genomes. Coronavirus replicase functions include more or less universal activities of plus-stranded RNA viruses, like an RNA polymerase (nsp12) and helicase (nsp13), but also a number of rare or even unique domains involved in mRNA capping (nsp14, nsp16) and fidelity control (nsp14). Several smaller subunits (nsp7–nsp10) act as crucial cofactors of these enzymes and contribute to the emerging “nsp interactome.” Understanding the structure, function, and interactions of the RNA-synthesizing machinery of coronaviruses will be key to rationalizing their evolutionary success and the development of improved control strategies.
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Affiliation(s)
- E J Snijder
- Leiden University Medical Center, Leiden, The Netherlands.
| | - E Decroly
- Aix-Marseille Université, AFMB UMR 7257, Marseille, France; CNRS, AFMB UMR 7257, Marseille, France
| | - J Ziebuhr
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany.
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Abstract
Coronaviruses have exceptionally large RNA genomes of approximately 30 kilobases. Genome replication and transcription is mediated by a multisubunit protein complex comprised of more than a dozen virus-encoded proteins. The protein complex is thought to bind specific cis-acting RNA elements primarily located in the 5'- and 3'-terminal genome regions and upstream of the open reading frames located in the 3'-proximal one-third of the genome. Here, we review our current understanding of coronavirus cis-acting RNA elements, focusing on elements required for genome replication and packaging. Recent bioinformatic, biochemical, and genetic studies suggest a previously unknown level of conservation of cis-acting RNA structures among different coronavirus genera and, in some cases, even beyond genus boundaries. Also, there is increasing evidence to suggest that individual cis-acting elements may be part of higher-order RNA structures involving long-range and dynamic RNA-RNA interactions between RNA structural elements separated by thousands of nucleotides in the viral genome. We discuss the structural and functional features of these cis-acting RNA elements and their specific functions in coronavirus RNA synthesis.
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Affiliation(s)
- R Madhugiri
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany
| | - M Fricke
- Faculty of Mathematics and Computer Science, Friedrich Schiller University Jena, Jena, Germany
| | - M Marz
- Faculty of Mathematics and Computer Science, Friedrich Schiller University Jena, Jena, Germany; FLI Leibniz Institute for Age Research, Jena, Germany
| | - J Ziebuhr
- Institute of Medical Virology, Justus Liebig University Giessen, Giessen, Germany.
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Abstract
Replication of the coronavirus genome requires continuous RNA synthesis, whereas transcription is a discontinuous process unique among RNA viruses. Transcription includes a template switch during the synthesis of subgenomic negative-strand RNAs to add a copy of the leader sequence. Coronavirus transcription is regulated by multiple factors, including the extent of base-pairing between transcription-regulating sequences of positive and negative polarity, viral and cell protein-RNA binding, and high-order RNA-RNA interactions. Coronavirus RNA synthesis is performed by a replication-transcription complex that includes viral and cell proteins that recognize cis-acting RNA elements mainly located in the highly structured 5' and 3' untranslated regions. In addition to many viral nonstructural proteins, the presence of cell nuclear proteins and the viral nucleocapsid protein increases virus amplification efficacy. Coronavirus RNA synthesis is connected with the formation of double-membrane vesicles and convoluted membranes. Coronaviruses encode proofreading machinery, unique in the RNA virus world, to ensure the maintenance of their large genome size.
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Affiliation(s)
- Isabel Sola
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain;
| | - Fernando Almazán
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain;
| | - Sonia Zúñiga
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain;
| | - Luis Enjuanes
- Department of Molecular and Cell Biology, Centro Nacional de Biotecnología-Consejo Superior de Investigaciones Científicas (CNB-CSIC), 28049 Madrid, Spain;
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Identification of a gamma interferon-activated inhibitor of translation-like RNA motif at the 3' end of the transmissible gastroenteritis coronavirus genome modulating innate immune response. mBio 2015; 6:e00105. [PMID: 25759500 PMCID: PMC4453530 DOI: 10.1128/mbio.00105-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
A 32-nucleotide (nt) RNA motif located at the 3′ end of the transmissible gastroenteritis coronavirus (TGEV) genome was found to specifically interact with the host proteins glutamyl-prolyl-tRNA synthetase (EPRS) and arginyl-tRNA synthetase (RRS). This RNA motif has high homology in sequence and secondary structure with the gamma interferon-activated inhibitor of translation (GAIT) element, which is located at the 3′ end of several mRNAs encoding proinflammatory proteins. The GAIT element is involved in the translation silencing of these mRNAs through its interaction with the GAIT complex (EPRS, heterogeneous nuclear ribonucleoprotein Q, ribosomal protein L13a, and glyceraldehyde 3-phosphate dehydrogenase) to favor the resolution of inflammation. Interestingly, we showed that the viral RNA motif bound the GAIT complex and inhibited the in vitro translation of a chimeric mRNA containing this RNA motif. To our knowledge, this is the first GAIT-like motif described in a positive RNA virus. To test the functional role of the GAIT-like RNA motif during TGEV infection, a recombinant coronavirus harboring mutations in this motif was engineered and characterized. Mutations of the GAIT-like RNA motif did not affect virus growth in cell cultures. However, an exacerbated innate immune response, mediated by the melanoma differentiation-associated gene 5 (MDA5) pathway, was observed in cells infected with the mutant virus compared with the response observed in cells infected with the parental virus. Furthermore, the mutant virus was more sensitive to beta interferon than the parental virus. All together, these data strongly suggested that the viral GAIT-like RNA motif modulates the host innate immune response. The innate immune response is the first line of antiviral defense that culminates with the synthesis of interferon and proinflammatory cytokines to limit virus replication. Coronaviruses encode several proteins that interfere with the innate immune response at different levels, but to date, no viral RNA counteracting antiviral response has been described. In this work, we have characterized a 32-nt RNA motif located at the 3′ end of the TGEV genome that specifically interacted with EPRS and RRS. This RNA motif presented high homology with the GAIT element, involved in the modulation of the inflammatory response. Moreover, the disruption of the viral GAIT-like RNA motif led to an exacerbated innate immune response triggered by MDA5, indicating that the GAIT-like RNA motif counteracts the host innate immune response. These novel findings may be of relevance for other coronaviruses and could serve as the basis for the development of novel antiviral strategies.
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50
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Yang D, Leibowitz JL. The structure and functions of coronavirus genomic 3' and 5' ends. Virus Res 2015; 206:120-33. [PMID: 25736566 PMCID: PMC4476908 DOI: 10.1016/j.virusres.2015.02.025] [Citation(s) in RCA: 289] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 02/22/2015] [Accepted: 02/23/2015] [Indexed: 01/19/2023]
Abstract
Coronaviruses (CoVs) are an important cause of illness in humans and animals. Most human coronaviruses commonly cause relatively mild respiratory illnesses; however two zoonotic coronaviruses, SARS-CoV and MERS-CoV, can cause severe illness and death. Investigations over the past 35 years have illuminated many aspects of coronavirus replication. The focus of this review is the functional analysis of conserved RNA secondary structures in the 5' and 3' of the betacoronavirus genomes. The 5' 350 nucleotides folds into a set of RNA secondary structures which are well conserved, and reverse genetic studies indicate that these structures play an important role in the discontinuous synthesis of subgenomic RNAs in the betacoronaviruses. These cis-acting elements extend 3' of the 5'UTR into ORF1a. The 3'UTR is similarly conserved and contains all of the cis-acting sequences necessary for viral replication. Two competing conformations near the 5' end of the 3'UTR have been shown to make up a potential molecular switch. There is some evidence that an association between the 3' and 5'UTRs is necessary for subgenomic RNA synthesis, but the basis for this association is not yet clear. A number of host RNA proteins have been shown to bind to the 5' and 3' cis-acting regions, but the significance of these in viral replication is not clear. Two viral proteins have been identified as binding to the 5' cis-acting region, nsp1 and N protein. A genetic interaction between nsp8 and nsp9 and the region of the 3'UTR that contains the putative molecular switch suggests that these two proteins bind to this region.
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Affiliation(s)
- Dong Yang
- Department of Microbiology, Immunology & Biochemistry, The University of Tennessee Health Science Center College of Medicine, Memphis, TN 38163, USA
| | - Julian L Leibowitz
- Department of Microbial Pathogenesis and Immunology, Texas A&M University, College of Medicine, College Station, TX 77843-1114, USA.
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