1
|
Buhlke EG, Hobbs AM, Rajput S, Rokusek B, Carlson DJ, Gillan C, Carlson KA. Characterization of Cross-Species Transmission of Drosophila melanogaster Nora Virus. Life (Basel) 2022; 12:1913. [PMID: 36431048 PMCID: PMC9697521 DOI: 10.3390/life12111913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/07/2022] [Accepted: 11/15/2022] [Indexed: 11/19/2022] Open
Abstract
Drosophila melanogaster Nora virus (DmNV) is a novel picorna-like virus first characterized in 2006. Since then, Nora virus has been detected in several non-Drosophila species, including insects in the Orders Hymenoptera, Lepidoptera, Coleoptera, and Orthoptera. The objective of this study was to determine if DmNV could infect individuals of other species of invertebrates besides D. melanogaster. The presence of DmNV in native invertebrates and commercially available stocks was determined. Laboratory-reared D. yakuba, D. mercatorum, Gryllodes sigillatus, Tenebrio molitor, Galleria mellonella, and Musca domestica were intentionally infected with DmNV. In addition, native invertebrates were collected and D. melanogaster stocks were purchased and screened for DmNV presence using reverse transcription-polymerase chain reaction (RT-PCR) before being intentionally infected for study. All Drosophila species and other invertebrates, except M. domestica, that were intentionally infected with DmNV ended up scoring positive for the virus via RT-PCR. DmNV infection was also detected in three native invertebrates (Spilosoma virginica, Diplopoda, and Odontotaenius disjunctus) and all commercially available stocks tested. These findings suggest that DmNV readily infects individuals of other species of invertebrates, while also appearing to be an endemic virus in both wild and laboratory D. melanogaster populations. The detection of DmNV in commercially available stocks presents a cautionary message for scientists using these stocks in studies of virology and immunology.
Collapse
Affiliation(s)
- Ella G. Buhlke
- Central City Senior High School, 1510 28th Street, Central City, NE 68826, USA
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Alexis M. Hobbs
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Sunanda Rajput
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Blase Rokusek
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Darby J. Carlson
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| | - Chelle Gillan
- Central City Senior High School, 1510 28th Street, Central City, NE 68826, USA
| | - Kimberly A. Carlson
- Department of Biology, University of Nebraska at Kearney, 2401 11th Ave, Kearney, NE 68849, USA
| |
Collapse
|
2
|
Multiple Viral Protein Genome-Linked Proteins Compensate for Viral Translation in a Positive-Sense Single-Stranded RNA Virus Infection. J Virol 2022; 96:e0069922. [PMID: 35993738 PMCID: PMC9472611 DOI: 10.1128/jvi.00699-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Viral protein genome-linked (VPg) protein plays an essential role in protein-primed replication of plus-stranded RNA viruses. VPg is covalently linked to the 5' end of the viral RNA genome via a phosphodiester bond typically at a conserved amino acid. Whereas most viruses have a single VPg, some viruses have multiple VPgs that are proposed to have redundant yet undefined roles in viral replication. Here, we use cricket paralysis virus (CrPV), a dicistrovirus that has four nonidentical copies of VPg, as a model to characterize the role of VPg copies in infection. Dicistroviruses contain two main open reading frames (ORFs) that are driven by distinct internal ribosome entry sites (IRESs). We systematically generated single and combinatorial deletions and mutations of VPg1 to VPg4 within the CrPV infectious clone and monitored viral yield in Drosophila S2 cells. Deletion of one to three VPg copies progressively decreased viral yield and delayed viral replication, suggesting a threshold number of VPgs for productive infection. Mass spectrometry analysis of CrPV VPg-linked RNAs revealed viral RNA linkage to either a serine or threonine in VPg, mutations of which in all VPgs attenuated infection. Mutating serine 4 in a single VPg abolished viral infection, indicating a dominant negative effect. Using viral minigenome reporters that monitor dicistrovirus 5' untranslated (UTR) and IRES translation revealed a relationship between VPg copy number and the ratio of distinct IRES translation activities. We uncovered a novel viral strategy whereby VPg copies in dicistrovirus genomes compensate for the relative IRES translation efficiencies to promote infection. IMPORTANCE Genetic duplication is exceedingly rare in small RNA viral genomes, as there is selective pressure to prevent RNA genomes from expanding. However, some small RNA viruses encode multiple copies of a viral protein, most notably an unusual viral protein that is linked to the viral RNA genome. Here, we investigate a family of viruses that contains multiple viral protein genome-linked proteins and reveal a novel viral strategy whereby viral protein copy number counterbalances differences in viral protein synthesis mechanisms.
Collapse
|
3
|
Bertola M, Mutinelli F. A Systematic Review on Viruses in Mass-Reared Edible Insect Species. Viruses 2021; 13:2280. [PMID: 34835086 PMCID: PMC8619331 DOI: 10.3390/v13112280] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 11/04/2021] [Accepted: 11/08/2021] [Indexed: 01/22/2023] Open
Abstract
Edible insects are expected to become an important nutrient source for animals and humans in the Western world in the near future. Only a few studies on viruses in edible insects with potential for industrial rearing have been published and concern only some edible insect species. Viral pathogens that can infect insects could be non-pathogenic, or pathogenic to the insects themselves, or to humans and animals. The objective of this systematic review is to provide an overview of the viruses detected in edible insects currently considered for use in food and/or feed in the European Union or appropriate for mass rearing, and to collect information on clinical symptoms in insects and on the vector role of insects themselves. Many different virus species have been detected in edible insect species showing promise for mass production systems. These viruses could be a risk for mass insect rearing systems causing acute high mortality, a drastic decline in growth in juvenile stages and in the reproductive performance of adults. Furthermore, some viruses could pose a risk to human and animal health where insects are used for food and feed.
Collapse
Affiliation(s)
- Michela Bertola
- Laboratory of Parasitology Micology and Sanitary Enthomology, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, PD, Italy
| | - Franco Mutinelli
- National Rereference Laboratory for Honey Bee Health, Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell’Università 10, 35020 Legnaro, PD, Italy;
| |
Collapse
|
4
|
Yasmin T, Thekke-Veetil T, Hobbs HA, Nelson BD, McCoppin NK, Lagos-Kutz D, Hartman GL, Lambert KN, Walker DR, Domier LL. Aphis glycines virus 1, a new bicistronic virus with two functional internal ribosome entry sites, is related to a group of unclassified viruses in the Picornavirales. J Gen Virol 2020; 101:105-111. [PMID: 31769392 DOI: 10.1099/jgv.0.001355] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A novel picorna-like virus, provisionally named Aphis glycines virus 1 (ApGlV1) was discovered by high-throughput sequencing of soybean total RNAs and detected in suction trap-collected Aphis glycines. The ApGlV1 genome contains two large ORFs organized similar to those of dicipiviruses in the Picornaviridae where ORFs 1 and 2 encode structural and nonstructural proteins, respectively. Both ORFs are preceded by internal ribosome entry site (IRES) elements. The 5' IRES was more active in dual luciferase activity assays than the IRES in the intergenic region. The ApGlV1 genome was predicted to encode a serine protease instead of a cysteine protease and showed very low aa sequence identities to recognized members of the Picornavirales. In phylogenetic analyses based on capsid protein and RNA-dependent RNA polymerase sequences, ApGlV1 consistently clustered with a group of unclassified bicistronic picorna-like viruses discovered from arthropods and plants that may represent a novel family in the order Picornavirales.
Collapse
Affiliation(s)
- Tuba Yasmin
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | | | - Houston A Hobbs
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Berlin D Nelson
- Deptartment of Plant Pathology, North Dakota State University, Fargo, ND, USA
| | - Nancy K McCoppin
- Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, Urbana, IL, USA.,Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Doris Lagos-Kutz
- Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, Urbana, IL, USA.,Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Glen L Hartman
- Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, Urbana, IL, USA.,Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Kris N Lambert
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - David R Walker
- Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, Urbana, IL, USA.,Department of Crop Sciences, University of Illinois, Urbana, IL, USA
| | - Leslie L Domier
- Department of Crop Sciences, University of Illinois, Urbana, IL, USA.,Soybean/Maize Germplasm, Pathology, and Genetics Research Unit, United States Department of Agriculture-Agricultural Research Service, Urbana, IL, USA
| |
Collapse
|
5
|
Gross L, Vicens Q, Einhorn E, Noireterre A, Schaeffer L, Kuhn L, Imler JL, Eriani G, Meignin C, Martin F. The IRES5'UTR of the dicistrovirus cricket paralysis virus is a type III IRES containing an essential pseudoknot structure. Nucleic Acids Res 2017; 45:8993-9004. [PMID: 28911115 PMCID: PMC5587806 DOI: 10.1093/nar/gkx622] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 07/07/2017] [Indexed: 02/02/2023] Open
Abstract
Cricket paralysis virus (CrPV) is a dicistrovirus. Its positive-sense single-stranded RNA genome contains two internal ribosomal entry sites (IRESs). The 5′ untranslated region (5′UTR) IRES5′UTR mediates translation of non-structural proteins encoded by ORF1 whereas the well-known intergenic region (IGR) IRESIGR is required for translation of structural proteins from open reading frame 2 in the late phase of infection. Concerted action of both IRES is essential for host translation shut-off and viral translation. IRESIGR has been extensively studied, in contrast the IRES5′UTR remains largely unexplored. Here, we define the minimal IRES element required for efficient translation initiation in drosophila S2 cell-free extracts. We show that IRES5′UTR promotes direct recruitment of the ribosome on the cognate viral AUG start codon without any scanning step, using a Hepatitis-C virus-related translation initiation mechanism. Mass spectrometry analysis revealed that IRES5′UTR recruits eukaryotic initiation factor 3, confirming that it belongs to type III class of IRES elements. Using Selective 2′-hydroxyl acylation analyzed by primer extension and DMS probing, we established a secondary structure model of 5′UTR and of the minimal IRES5′UTR. The IRES5′UTR contains a pseudoknot structure that is essential for proper folding and ribosome recruitment. Overall, our results pave the way for studies addressing the synergy and interplay between the two IRES from CrPV.
Collapse
Affiliation(s)
- Lauriane Gross
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Quentin Vicens
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Evelyne Einhorn
- Université de Strasbourg, CNRS, Réponse Immunitaire et Développement chez les Insectes, UPR 9022, F-67000 Strasbourg, France
| | - Audrey Noireterre
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Laure Schaeffer
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Lauriane Kuhn
- Université de Strasbourg, CNRS, Plateforme Protéomique Strasbourg-Esplanade, F-67000 Strasbourg, France
| | - Jean-Luc Imler
- Université de Strasbourg, CNRS, Réponse Immunitaire et Développement chez les Insectes, UPR 9022, F-67000 Strasbourg, France
| | - Gilbert Eriani
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| | - Carine Meignin
- Université de Strasbourg, CNRS, Réponse Immunitaire et Développement chez les Insectes, UPR 9022, F-67000 Strasbourg, France
| | - Franck Martin
- Université de Strasbourg, CNRS, Architecture et Réactivité de l'ARN, UPR 9002, F-67000 Strasbourg, France
| |
Collapse
|
6
|
Disruption of Stress Granule Formation by the Multifunctional Cricket Paralysis Virus 1A Protein. J Virol 2017; 91:JVI.01779-16. [PMID: 28003491 DOI: 10.1128/jvi.01779-16] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Accepted: 12/15/2016] [Indexed: 12/26/2022] Open
Abstract
Stress granules (SGs) are cytosolic ribonucleoprotein aggregates that are induced during cellular stress. Several viruses modulate SG formation, suggesting that SGs have an impact on virus infection. However, the mechanisms and impact of modulating SG assembly in infected cells are not completely understood. In this study, we identify the dicistrovirus cricket paralysis virus 1A (CrPV-1A) protein that functions to inhibit SG assembly during infection. Moreover, besides inhibiting RNA interference, CrPV-1A also inhibits host transcription, which indirectly modulates SG assembly. Thus, CrPV-1A is a multifunctional protein. We identify a key R146A residue that is responsible for these effects, and mutant CrPV(R146A) virus infection is attenuated in Drosophila melanogaster S2 cells and adult fruit flies and results in increased SG formation. Treatment of CrPV(R146A)-infected cells with actinomycin D, which represses transcription, restores SG assembly suppression and viral yield. In summary, CrPV-1A modulates several cellular processes to generate a cellular environment that promotes viral translation and replication.IMPORTANCE RNA viruses encode a limited set of viral proteins to modulate an array of cellular processes in order to facilitate viral replication and inhibit antiviral defenses. In this study, we identified a viral protein, called CrPV-1A, within the dicistrovirus cricket paralysis virus that can inhibit host transcription, modulate viral translation, and block a cellular process called stress granule assembly. We also identified a specific amino acid within CrPV-1A that is important for these cellular processes and that mutant viruses containing mutations of CrPV-1A attenuate virus infection. We also demonstrate that the CrPV-1A protein can also modulate cellular processes in human cells, suggesting that the mode of action of CrPV-1A is conserved. We propose that CrPV-1A is a multifunctional, versatile protein that creates a cellular environment in virus-infected cells that permits productive virus infection.
Collapse
|
7
|
Ericson BL, Carlson DJ, Carlson KA. Characterization of Nora Virus Structural Proteins via Western Blot Analysis. SCIENTIFICA 2016; 2016:9067848. [PMID: 27298753 PMCID: PMC4889860 DOI: 10.1155/2016/9067848] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2015] [Accepted: 05/04/2016] [Indexed: 06/06/2023]
Abstract
Nora virus is a single stranded RNA picorna-like virus with four open reading frames (ORFs). The coding potentials of the ORFs are not fully characterized, but ORF3 and ORF4 are believed to encode the capsid proteins (VP3, VP4a, VP4b, and VP4c) comprising the virion. To determine the polypeptide composition of Nora virus virions, polypeptides from purified virus were compared to polypeptides detected in Nora virus infected Drosophila melanogaster. Nora virus was purified from infected flies and used to challenge mice for the production of antisera. ORF3, ORF4a, ORF4b, and ORF4c were individually cloned and expressed in E. coli; resultant recombinant proteins purified and were used to make monospecific antisera. Antisera were evaluated via Western blot against whole virus particles and Nora virus infected fly lysates. Viral purification yielded two particle types with densities of ~1.31 g/mL (empty particles) and ~1.33 g/mL (complete virions). Comparison of purified virus polypeptide composition to Nora virus infected D. melanogaster lysate showed the number of proteins in infected cell lysates is less than purified virus. Our results suggest the virion is composed of 6 polypeptides, VP3, VP4a, two forms of VP4b, and two forms of VP4c. This polypeptide composition is similar to other small RNA insect viruses.
Collapse
Affiliation(s)
- Brad L. Ericson
- Biology Department, University of Nebraska at Kearney, 2401 11th Avenue, Kearney, NE 68849, USA
| | - Darby J. Carlson
- Biology Department, University of Nebraska at Kearney, 2401 11th Avenue, Kearney, NE 68849, USA
| | - Kimberly A. Carlson
- Biology Department, University of Nebraska at Kearney, 2401 11th Avenue, Kearney, NE 68849, USA
| |
Collapse
|
8
|
Temporal Regulation of Distinct Internal Ribosome Entry Sites of the Dicistroviridae Cricket Paralysis Virus. Viruses 2016; 8:v8010025. [PMID: 26797630 PMCID: PMC4728584 DOI: 10.3390/v8010025] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/08/2016] [Accepted: 01/11/2016] [Indexed: 01/04/2023] Open
Abstract
Internal ribosome entry is a key mechanism for viral protein synthesis in a subset of RNA viruses. Cricket paralysis virus (CrPV), a member of Dicistroviridae, has a positive-sense single strand RNA genome that contains two internal ribosome entry sites (IRES), a 5′untranslated region (5′UTR) and intergenic region (IGR) IRES, that direct translation of open reading frames (ORF) encoding the viral non-structural and structural proteins, respectively. The regulation of and the significance of the CrPV IRESs during infection are not fully understood. In this study, using a series of biochemical assays including radioactive-pulse labelling, reporter RNA assays and ribosome profiling, we demonstrate that while 5′UTR IRES translational activity is constant throughout infection, IGR IRES translation is delayed and then stimulated two to three hours post infection. The delay in IGR IRES translation is not affected by inhibiting global translation prematurely via treatment with Pateamine A. Using a CrPV replicon that uncouples viral translation and replication, we show that the increase in IGR IRES translation is dependent on expression of non-structural proteins and is greatly stimulated when replication is active. Temporal regulation by distinct IRESs within the CrPV genome is an effective viral strategy to ensure optimal timing and expression of viral proteins to facilitate infection.
Collapse
|
9
|
Abaeva IS, Pestova TV, Hellen CUT. Attachment of ribosomal complexes and retrograde scanning during initiation on the Halastavi árva virus IRES. Nucleic Acids Res 2016; 44:2362-77. [PMID: 26783202 PMCID: PMC4797288 DOI: 10.1093/nar/gkw016] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 01/07/2016] [Indexed: 01/02/2023] Open
Abstract
Halastavi árva virus (HalV) has a positive-sense RNA genome, with an 827 nt-long 5' UTR and an intergenic region separating two open reading frames. Whereas the encoded proteins are most homologous to Dicistrovirus polyproteins, its 5' UTR is distinct. Here, we report that the HalV 5' UTR comprises small stem-loop domains separated by long single-stranded areas and a large A-rich unstructured region surrounding the initiation codon AUG828, and possesses cross-kingdom internal ribosome entry site (IRES) activity. In contrast to most viral IRESs, it does not depend on structural integrity and specific interaction of a structured element with a translational component, and is instead determined by the unstructured region flanking AUG828. eIF2, eIF3, eIF1 and eIF1A promote efficient 48S initiation complex formation at AUG828, which is reduced ∼5-fold on omission of eIF1 and eIF1A. Initiation involves direct attachment of 43S preinitiation complexes within a short window at or immediately downstream of AUG828. 40S and eIF3 are sufficient for initial binding. After attachment, 43S complexes undergo retrograde scanning, strongly dependent on eIF1 and eIF1A. eIF4A/eIF4G stimulated initiation only at low temperatures or on mutants, in which areas surrounding AUG828 had been replaced by heterologous sequences. However, they strongly promoted initiation at AUG872, yielding a proline-rich oligopeptide.
Collapse
Affiliation(s)
- Irina S Abaeva
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, 11203, NY, USA
| | - Tatyana V Pestova
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, 11203, NY, USA
| | | |
Collapse
|
10
|
Kerr CH, Wang QS, Keatings K, Khong A, Allan D, Yip CK, Foster LJ, Jan E. The 5' untranslated region of a novel infectious molecular clone of the dicistrovirus cricket paralysis virus modulates infection. J Virol 2015; 89:5919-34. [PMID: 25810541 PMCID: PMC4442438 DOI: 10.1128/jvi.00463-15] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 03/12/2015] [Indexed: 02/05/2023] Open
Abstract
UNLABELLED Dicistroviridae are a family of RNA viruses that possesses a single-stranded positive-sense RNA genome containing two distinct open reading frames (ORFs), each preceded by an internal ribosome entry site that drives translation of the viral structural and nonstructural proteins, respectively. The type species, Cricket paralysis virus (CrPV), has served as a model for studying host-virus interactions; however, investigations into the molecular mechanisms of CrPV and other dicistroviruses have been limited as an established infectious clone was elusive. Here, we report the construction of an infectious molecular clone of CrPV. Transfection of in vitro-transcribed RNA from the CrPV clone into Drosophila Schneider line 2 (S2) cells resulted in cytopathic effects, viral RNA accumulation, detection of negative-sense viral RNA, and expression of viral proteins. Transmission electron microscopy, viral titers, and immunofluorescence-coupled transwell assays demonstrated that infectious viral particles are released from transfected cells. In contrast, mutant clones containing stop codons in either ORF decreased virus infectivity. Injection of adult Drosophila flies with virus derived from CrPV clones but not UV-inactivated clones resulted in mortality. Molecular analysis of the CrPV clone revealed a 196-nucleotide duplication within its 5' untranslated region (UTR) that stimulated translation of reporter constructs. In cells infected with the CrPV clone, the duplication inhibited viral infectivity yet did not affect viral translation or RNA accumulation, suggesting an effect on viral packaging or entry. The generation of the CrPV infectious clone provides a powerful tool for investigating the viral life cycle and pathogenesis of dicistroviruses and may further understanding of fundamental host-virus interactions in insect cells. IMPORTANCE Dicistroviridae, which are RNA viruses that infect arthropods, have served as a model to gain insights into fundamental host-virus interactions in insect cells. Further insights into the viral molecular mechanisms are hampered due to a lack of an established infectious clone. We report the construction of the first infectious clone of the dicistrovirus, cricket paralysis virus (CrPV). We show that transfection of the CrPV clone RNA into Drosophila cells led to production of infectious particles that resemble natural CrPV virions and result in cytopathic effects and expression of CrPV proteins and RNA in infected cells. The CrPV clone should provide insights into the dicistrovirus life cycle and host-virus interactions in insect cells. Using this clone, we find that a 196-nucleotide duplication within the 5' untranslated region of the CrPV clone increased viral translation in reporter constructs but decreased virus infectivity, thus revealing a balance that interplays between viral translation and replication.
Collapse
Affiliation(s)
- Craig H Kerr
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada Centre for High-Throughput Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Qing S Wang
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kathleen Keatings
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anthony Khong
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Douglas Allan
- Department of Cellular and Physiological Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Calvin K Yip
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada Centre for High-Throughput Biology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Eric Jan
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
11
|
Susevich ML, Marti GA, Metz GE, Echeverría MG. First study of different insect cells to triatoma virus infection. Curr Microbiol 2014; 70:470-5. [PMID: 25481388 DOI: 10.1007/s00284-014-0746-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 10/23/2014] [Indexed: 11/27/2022]
Abstract
The use of viruses for biological control is a new option to be considered. The family Dicistroviridae, which affects only invertebrates, is one of the families that have been proposed for this purpose. The Triatoma virus (TrV), a member of this family, affects triatomine transmitters of Chagas disease, which is endemic in Latin America but also expanding its worldwide distribution. To this end, we attempted virus replication in Diptera, Aedes albopictus (clone C6/36) and Lepidoptera Spodoptera frugiperda (SF9, SF21) and High Five (H5) cell lines. The methodologies used were transfection process, direct inoculation (purified virus), and inoculation of purified virus with trypsin. Results were confirmed by SDS-PAGE, Western blotting, RT-PCR, electron microscopy, and immunofluorescence. According to the results obtained, further analysis of susceptibility/infection of H5 cells to TrV required to be studied.
Collapse
Affiliation(s)
- María Laura Susevich
- Centro de Estudios Parasitológicos y de Vectores (CEPAVE-CCT-La Plata-CONICET-UNLP), 2 #584, 1900, La Plata, Argentina
| | | | | | | |
Collapse
|
12
|
Au HHT, Jan E. Novel viral translation strategies. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 5:779-801. [PMID: 25045163 PMCID: PMC7169809 DOI: 10.1002/wrna.1246] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 05/03/2014] [Accepted: 05/08/2014] [Indexed: 01/06/2023]
Abstract
Viral genomes are compact and encode a limited number of proteins. Because they do not encode components of the translational machinery, viruses exhibit an absolute dependence on the host ribosome and factors for viral messenger RNA (mRNA) translation. In order to recruit the host ribosome, viruses have evolved unique strategies to either outcompete cellular transcripts that are efficiently translated by the canonical translation pathway or to reroute translation factors and ribosomes to the viral genome. Furthermore, viruses must evade host antiviral responses and escape immune surveillance. This review focuses on some recent major findings that have revealed unconventional strategies that viruses utilize, which include usurping the host translational machinery, modulating canonical translation initiation factors to specifically enhance or repress overall translation for the purpose of viral production, and increasing viral coding capacity. The discovery of these diverse viral strategies has provided insights into additional translational control mechanisms and into the viral host interactions that ensure viral protein synthesis and replication. WIREs RNA 2014, 5:779–801. doi: 10.1002/wrna.1246 This article is categorized under:
Translation > Translation Mechanisms Translation > Translation Regulation
Collapse
Affiliation(s)
- Hilda H T Au
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | | |
Collapse
|
13
|
Boncristiani HF, Evans JD, Chen Y, Pettis J, Murphy C, Lopez DL, Simone-Finstrom M, Strand M, Tarpy DR, Rueppell O. In vitro infection of pupae with Israeli acute paralysis virus suggests disturbance of transcriptional homeostasis in honey bees (Apis mellifera). PLoS One 2013; 8:e73429. [PMID: 24039938 PMCID: PMC3764161 DOI: 10.1371/journal.pone.0073429] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Accepted: 07/19/2013] [Indexed: 01/08/2023] Open
Abstract
The ongoing decline of honey bee health worldwide is a serious economic and ecological concern. One major contributor to the decline are pathogens, including several honey bee viruses. However, information is limited on the biology of bee viruses and molecular interactions with their hosts. An experimental protocol to test these systems was developed, using injections of Israeli Acute Paralysis Virus (IAPV) into honey bee pupae reared ex-situ under laboratory conditions. The infected pupae developed pronounced but variable patterns of disease. Symptoms varied from complete cessation of development with no visual evidence of disease to rapid darkening of a part or the entire body. Considerable differences in IAPV titer dynamics were observed, suggesting significant variation in resistance to IAPV among and possibly within honey bee colonies. Thus, selective breeding for virus resistance should be possible. Gene expression analyses of three separate experiments suggest IAPV disruption of transcriptional homeostasis of several fundamental cellular functions, including an up-regulation of the ribosomal biogenesis pathway. These results provide first insights into the mechanisms of IAPV pathogenicity. They mirror a transcriptional survey of honey bees afflicted with Colony Collapse Disorder and thus support the hypothesis that viruses play a critical role in declining honey bee health.
Collapse
Affiliation(s)
- Humberto F. Boncristiani
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, United States of America
- * E-mail:
| | - Jay D. Evans
- Bee Research Laboratory, Agricultural Research Service of the United States Department of Agriculture, Beltsville, Maryland, United States of America
| | - Yanping Chen
- Bee Research Laboratory, Agricultural Research Service of the United States Department of Agriculture, Beltsville, Maryland, United States of America
| | - Jeff Pettis
- Bee Research Laboratory, Agricultural Research Service of the United States Department of Agriculture, Beltsville, Maryland, United States of America
| | - Charles Murphy
- Soybean Genomics and Improvement, Agricultural Research Service of the United States Department of Agriculture, Beltsville, Maryland, United States of America
| | - Dawn L. Lopez
- Bee Research Laboratory, Agricultural Research Service of the United States Department of Agriculture, Beltsville, Maryland, United States of America
| | - Michael Simone-Finstrom
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Micheline Strand
- United States Army Research Office, Division of Life Sciences, Research Triangle Park, North Carolina, United States of America
| | - David R. Tarpy
- Department of Entomology, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Olav Rueppell
- Department of Biology, University of North Carolina at Greensboro, Greensboro, North Carolina, United States of America
| |
Collapse
|
14
|
Infection of honey bees with acute bee paralysis virus does not trigger humoral or cellular immune responses. Arch Virol 2012; 157:689-702. [PMID: 22258854 PMCID: PMC3314816 DOI: 10.1007/s00705-012-1223-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 12/04/2011] [Indexed: 11/28/2022]
Abstract
We have studied the responses of honey bees at different life stages (Apis mellifera) to controlled infection with acute bee paralysis virus and have identified the haemolymph of infected larvae and adult worker bees as the compartment where massive propagation of ABPV occurs. Insects respond with a broad spectrum of induced innate immune reactions to bacterial infections, whereas defence mechanisms based on RNA interference play a major role in antiviral immunity. In this study, we have determined that honey bee larvae and adult workers do not produce a humoral immune reaction upon artificial infection with ABPV, in contrast to control individuals challenged with Escherichia coli. ABPV-infected bees produced neither elevated levels of specific antimicrobial peptides (AMPs), such as hymenoptaecin and defensin, nor any general antimicrobial activity, as revealed by inhibition-zone assays. Additionally, adult bees did not generate melanised nodules upon ABPV infection, an important cellular immune function activated by bacteria and viruses in some insects. Challenge of bees with both ABPV and E. coli showed that innate humoral and cellular immune reactions are induced in mixed infections, albeit at a reduced level.
Collapse
|
15
|
Alternative reading frame selection mediated by a tRNA-like domain of an internal ribosome entry site. Proc Natl Acad Sci U S A 2012; 109:E630-9. [PMID: 22247292 DOI: 10.1073/pnas.1111303109] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The dicistrovirus intergenic region internal ribosome entry site (IRES) utilizes a unique mechanism, involving P-site tRNA mimicry, to directly assemble 80S ribosomes and initiate translation at a specific non-AUG codon in the ribosomal A site. A subgroup of dicistrovirus genomes contains an additional stem-loop 5'-adjacent to the IRES and a short open reading frame (ORFx) that overlaps the viral structural polyprotein ORF (ORF2) in the +1 reading frame. Using mass spectrometry and extensive mutagenesis, we show that, besides directing ORF2 translation, the Israeli acute paralysis dicistrovirus IRES also directs ORFx translation. The latter is mediated by a UG base pair adjacent to the P-site tRNA-mimicking domain. An ORFx peptide was detected in virus-infected honey bees by multiple reaction monitoring mass spectrometry. Finally, the 5' stem-loop increases IRES activity and may couple translation of the two major ORFs of the virus. This study reveals a novel viral strategy in which a tRNA-like IRES directs precise, initiator Met-tRNA-independent translation of two overlapping ORFs.
Collapse
|
16
|
Agirre J, Aloria K, Arizmendi JM, Iloro I, Elortza F, Sánchez-Eugenia R, Marti GA, Neumann E, Rey FA, Guérin DMA. Capsid protein identification and analysis of mature Triatoma virus (TrV) virions and naturally occurring empty particles. Virology 2010; 409:91-101. [PMID: 21030058 DOI: 10.1016/j.virol.2010.09.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/09/2010] [Accepted: 09/29/2010] [Indexed: 01/01/2023]
Abstract
Triatoma virus (TrV) is a non-enveloped +ssRNA virus belonging to the insect virus family Dicistroviridae. Mass spectrometry (MS) and gel electrophoresis were used to detect the previously elusive capsid protein VP4. Its cleavage sites were established by sequencing the N-terminus of the protein precursor and MS, and its stoichiometry with respect to the other major capsid proteins (VP1-3) was found to be 1:1. We also characterized the polypeptides comprising the naturally occurring non-infectious empty capsids, i.e., RNA-free TrV particles. The empty particles were composed of VP0-VP3 plus at least seven additional polypeptides, which were identified as products of the capsid precursor polyprotein. We conclude that VP4 protein appears as a product of RNA encapsidation, and that defective processing of capsid proteins precludes genome encapsidation.
Collapse
Affiliation(s)
- Jon Agirre
- Unidad de Biofísica CSIC-UPV/EHU, Barrio Sarriena S/N, 48940 Leioa, Bizkaia, Spain
| | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
The dicistrovirus is a positive-strand single-stranded RNA virus that possesses two internal ribosome entry sites (IRES) that direct translation of distinct open reading frames encoding the viral structural and nonstructural proteins. Through an unusual mechanism, the intergenic region (IGR) IRES responsible for viral structural protein expression mimics a tRNA to directly recruit the ribosome and set the ribosome into translational elongation. In this study, we explored the mechanism of host translational shutoff in Drosophila S2 cells infected by the dicistrovirus, cricket paralysis virus (CrPV). CrPV infection of S2 cells results in host translational shutoff concomitant with an increase in viral protein synthesis. CrPV infection resulted in the dissociation of eukaryotic translation initiation factor 4G (eIF4G) and eIF4E early in infection and the induction of deIF2alpha phosphorylation at 3 h postinfection, which lags after the initial inhibition of host translation. Forced dephosphorylation of deIF2alpha by overexpression of dGADD34, which activates protein phosphatase I, did not prevent translational shutoff nor alter virus production, demonstrating that deIF2alpha phosphorylation is dispensable for host translational shutoff. However, premature induction of deIF2alpha phosphorylation by thapsigargin treatment early in infection reduced viral protein synthesis and replication. Finally, translation mediated by the 5' untranslated region (5'UTR) and the IGR IRES were resistant to impairment of eIF4F or eIF2 in translation extracts. These results support a model by which the alteration of the deIF4F complex contribute to the shutoff of host translation during CrPV infection, thereby promoting viral protein synthesis via the CrPV 5'UTR and IGR IRES.
Collapse
|
18
|
Translation initiation from the ribosomal A site or the P site, dependent on the conformation of RNA pseudoknot I in dicistrovirus RNAs. Mol Cell 2009; 35:181-90. [PMID: 19647515 DOI: 10.1016/j.molcel.2009.05.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 03/26/2009] [Accepted: 05/19/2009] [Indexed: 11/23/2022]
Abstract
Translation initiation of the second ORF of insect dicistrovirus RNA depends on an internal ribosomal entry site (IRES) in its intergenic region (IGR) and is exceptional in using a codon other than AUG and in not using the canonical initiator methionine tRNA. Studies in vitro suggest that pseudoknot I (PKI) immediately preceding the initiation codon occupies the ribosomal P site and that an elongator tRNA initiates translation from the ribosomal A site. Using dicistronic reporters carrying mutations in the initiation codon of the second ORF and mutant elongator or initiator tRNAs capable of reading these codons, we provide direct evidence for initiation from the A site in mammalian cells and, under certain conditions, also from the P site. Initiation from the A but not the P site requires PKI. Thus, PKI structure may be dynamic, and optimal IGR IRES-mediated translation of dicistroviral RNAs may require trans-acting factors to stabilize PKI.
Collapse
|
19
|
Balvay L, Soto Rifo R, Ricci EP, Decimo D, Ohlmann T. Structural and functional diversity of viral IRESes. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1789:542-57. [PMID: 19632368 DOI: 10.1016/j.bbagrm.2009.07.005] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 07/17/2009] [Accepted: 07/19/2009] [Indexed: 01/06/2023]
Abstract
Some 20 years ago, the study of picornaviral RNA translation led to the characterization of an alternative mechanism of initiation by direct ribosome binding to the 5' UTR. By using a bicistronic vector, it was shown that the 5' UTR of the poliovirus (PV) or the Encephalomyelitis virus (EMCV) had the ability to bind the 43S preinitiation complex in a 5' and cap-independent manner. This is rendered possible by an RNA domain called IRES for Internal Ribosome Entry Site which enables efficient translation of an mRNA lacking a 5' cap structure. IRES elements have now been found in many different viral families where they often confer a selective advantage to allow ribosome recruitment under conditions where cap-dependent protein synthesis is severely repressed. In this review, we compare and contrast the structure and function of IRESes that are found within 4 distinct family of RNA positive stranded viruses which are the (i) Picornaviruses; (ii) Flaviviruses; (iii) Dicistroviruses; and (iv) Lentiviruses.
Collapse
Affiliation(s)
- Laurent Balvay
- Unité de Virologie Humaine, Ecole Normale Supérieure de Lyon, Lyon F-693643, France
| | | | | | | | | |
Collapse
|
20
|
Hellen CUT. IRES-induced conformational changes in the ribosome and the mechanism of translation initiation by internal ribosomal entry. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2009; 1789:558-70. [PMID: 19539793 DOI: 10.1016/j.bbagrm.2009.06.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2009] [Revised: 06/04/2009] [Accepted: 06/11/2009] [Indexed: 01/02/2023]
Abstract
Translation of the genomes of several positive-sense RNA viruses follows end-independent initiation on an internal ribosomal entry site (IRES) in the viral mRNA. There are four major IRES groups, and despite major differences in the mechanisms that they use, one unifying characteristic is that each mechanism involves essential non-canonical interactions of the IRES with components of the canonical translational apparatus. Thus the approximately 200nt.-long Type 4 IRESs (epitomized by Cricket paralysis virus) bind directly to the intersubunit space on the ribosomal 40S subunit, followed by joining to a 60S subunit to form active ribosomes by a factor-independent mechanism. The approximately 300nt.-long type 3 IRESs (epitomized by Hepatitis C virus) binds independently to eukaryotic initiation factor (eIF) 3, and to the solvent-accessible surface and E-site of the 40S subunit: addition of eIF2-GTP/initiator tRNA is sufficient to form a 48S complex that can join a 60S subunit in an eIF5/eIF5B-mediated reaction to form an active ribosome. Recent cryo-electron microscopy and biochemical analyses have revealed a second general characteristic of the mechanisms of initiation on Type 3 and Type 4 IRESs. Both classes of IRES induce similar conformational changes in the ribosome that influence entry, positioning and fixation of mRNA in the ribosomal decoding channel. HCV-like IRESs also stabilize binding of initiator tRNA in the peptidyl (P) site of the 40S subunit, whereas Type 4 IRESs induce changes in the ribosome that likely promote subsequent steps in the translation process, including subunit joining and elongation.
Collapse
Affiliation(s)
- Christopher U T Hellen
- Department of Cell Biology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 44, Brooklyn, NY 11203, USA.
| |
Collapse
|
21
|
An atypical IRES within the 5′ UTR of a dicistrovirus genome. Virus Res 2009; 139:157-65. [DOI: 10.1016/j.virusres.2008.07.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2008] [Revised: 07/02/2008] [Accepted: 07/08/2008] [Indexed: 12/27/2022]
|
22
|
Abstract
The fruit fly Drosophila melanogaster is a powerful model to study host-pathogen interactions. Most studies so far have focused on extracellular pathogens such as bacteria and fungi. More recently, viruses have come to the front, and RNA interference was shown to play a critical role in the control of viral infections in drosophila. We review here our current knowledge on drosophila viruses. A diverse set of RNA viruses belonging to several families (Rhabdoviridae, Dicistroviridae, Birnaviridae, Reoviridae, Errantiviridae) has been reported in D. melanogaster. By contrast, no DNA virus has been recovered up to now. The drosophila viruses represent powerful tools to study virus-cell interactions in vivo. Analysis of the literature however reveals that for many of them, important gaps exist in our understanding of their replication cycle, genome organization, morphology or pathogenesis. The data obtained in the past few years on antiviral defense mechanisms in drosophila, which point to evolutionary conserved pathways, highlight the potential of the D. melanogaster model to study antiviral innate immunity and to better understand the complex interaction between arthropod-borne viruses and their insect vectors.
Collapse
|
23
|
Nakashima N, Nakamura Y. Cleavage sites of the “P3 region” in the nonstructural polyprotein precursor of a dicistrovirus. Arch Virol 2008; 153:1955-60. [DOI: 10.1007/s00705-008-0208-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2008] [Accepted: 08/29/2008] [Indexed: 11/24/2022]
|
24
|
Moore NF, Reavy B, Pullin JS, Plus N. The polypeptides induced in Drosophila cells by Drosophila C virus (strain Ouarzazate). Virology 2008; 112:411-6. [PMID: 18635073 DOI: 10.1016/0042-6822(81)90288-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/03/1981] [Indexed: 10/26/2022]
Abstract
The Ouarzazate strain of Drosophila virus (DCV0) was grown in Drosophila melanogaster tissue culture cells, and [35S]methionine-labeled virions were found to contain a group of major structural proteins with a molecular weight of approximately 30,000 as well as several minor proteins of higher molecular weight and a protein of approximately 10,000 daltons. Using a range of pulses, chases and gel systems, examination of the intracellular proteins induced by DCV0 showed the presence of 17 polypeptides not found in uninfected cells. The synthesis of virus-induced polypeptides was extremely asymmetric with a rapid appearance of the major virus structural proteins and a much slower appearance of the lowest molecular weight structural protein (VP4). Processing of virus-induced proteins including the appearance of VP4 was demonstrated using pulse-chase after pulsing with [35S]methionine. While the highest molecular weight induced protein found in infected cells was 146,000, pretreatment of cells with iodoacetamide resulted in the appearance of a protein with a molecular weight of approximately 200,000. The evidence presented in this paper supports the inclusion of DCV0 in the Picornaviridae group.
Collapse
Affiliation(s)
- N F Moore
- Natural Environment Research Council, Institute of Virology, 5 South Parks Road, Oxford OX1 3UB, United Kingdom
| | | | | | | |
Collapse
|
25
|
Nakashima N, Shibuya N. Multiple coding sequences for the genome-linked virus protein (VPg) in dicistroviruses. J Invertebr Pathol 2006; 92:100-4. [PMID: 16707137 DOI: 10.1016/j.jip.2006.03.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2005] [Revised: 03/15/2006] [Accepted: 03/29/2006] [Indexed: 11/23/2022]
Abstract
N-terminal Edman sequencing of the genome-linked viral protein (VPg) of Plautia stali intestine virus (PSIV, Dicistroviridae) detected heterologus residues. The VPg sequence determined was found to be triplicated in the nonstructural protein precursor. Multiple VPg-like sequences were also found in 10 of the 12 dicistroviruses with a maximum of six copies in Solenopsis invicta virus-1. We postulate that redundant VPg coding sequences facilitate multiplication of dicistroviruses, because fewer cycle of translation of the nonstructural protein precursor produces larger amounts of VPg proteins in parallel with the increased production of capsid proteins by the intergenic internal ribosome entry site mediated translation.
Collapse
Affiliation(s)
- Nobuhiko Nakashima
- National Institute of Agrobiological Sciences, Owashi, Tsukuba, Ibaraki 305-8634, Japan.
| | | |
Collapse
|
26
|
Jan E. Divergent IRES elements in invertebrates. Virus Res 2005; 119:16-28. [PMID: 16307820 DOI: 10.1016/j.virusres.2005.10.011] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2005] [Revised: 09/05/2005] [Accepted: 10/20/2005] [Indexed: 02/05/2023]
Abstract
Viruses have evolved unique strategies and mechanisms to recruit ribosomes to ensure continued translation of their viral RNA during infection. The Dicistroviridae family of invertebrate viruses contains an unusual internal ribosome entry site (IRES), which can directly recruit ribosomes in the absence of initiation factors. Moreover, this IRES initiates translation at a non-AUG codon independent of an initiator Met-tRNA. Recent studies have shown that the IRES mimicks a tRNA to interact with and manipulate the ribosome. The presence of this divergent IRES likely allows translation of the dicistroviral RNA during infection when host translation is compromised. This review will explore the unique properties of this unprecedented mechanism of gene expression. Specific topics will examine structural components of the IRES, the mechanism of initiating translation at non-AUG codons and the regulation of this IRES in vivo. The existence of this mechanism suggests that the repertoire of open reading frames in our genome may be greater than anticipated.
Collapse
Affiliation(s)
- Eric Jan
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305, USA.
| |
Collapse
|
27
|
Pisarev AV, Shirokikh NE, Hellen CUT. Translation initiation by factor-independent binding of eukaryotic ribosomes to internal ribosomal entry sites. C R Biol 2005; 328:589-605. [PMID: 15992743 DOI: 10.1016/j.crvi.2005.02.004] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2005] [Accepted: 02/16/2005] [Indexed: 02/05/2023]
Abstract
Two exceptional mechanisms of eukaryotic translation initiation have recently been identified that differ fundamentally from the canonical factor-mediated, end-dependent mechanism of ribosomal attachment to mRNA. Instead, ribosomal 40S subunits bind in a factor-independent manner to the internal ribosomal entry site (IRES) in an mRNA. These two mechanisms are exemplified by initiation on the unrelated approximately 300 nt.-long Hepatitis C virus (HCV) IRES and the approximately 200 nt.-long cricket paralysis virus (CrPV) intergenic region (IGR) IRES, respectively. Ribosomal binding involves interaction with multiple non-contiguous sites on these IRESs, and therefore also differs from the factor-independent attachment of prokaryotic ribosomes to mRNA, which involves base-pairing to the linear Shine-Dalgarno sequence. The HCV IRES binds to the solvent side of the 40S subunit, docks a domain of the IRES into the ribosomal exit (E) site and places the initiation codon in the ribosomal peptidyl (P) site. Subsequent binding of eIF3 and the eIF2-GTP/initiator tRNA complex to form a 48S complex is followed by subunit joining to form an 80S ribosome. The CrPV IRES binds to ribosomes in a very different manner, by occupying the ribosomal E and P sites in the intersubunit cavity, thereby excluding initiator tRNA. Ribosomes enter the elongation stage of translation directly, without any involvement of initiator tRNA or initiation factors, following recruitment of aminoacyl-tRNA to the ribosomal aminoacyl (A) site and translocation of it to the P site.
Collapse
Affiliation(s)
- Andrey V Pisarev
- Department of Microbiology and Immunology, State University of New York, SUNY, 450 Clarkson Ave., Brooklyn, NY 11203, USA
| | | | | |
Collapse
|
28
|
Dhar AK, Cowley JA, Hasson KW, Walker PJ. Genomic organization, biology, and diagnosis of Taura syndrome virus and yellowhead virus of penaeid shrimp. Adv Virus Res 2004; 63:353-421. [PMID: 15530565 PMCID: PMC7127055 DOI: 10.1016/s0065-3527(04)63006-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Arun K Dhar
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | | | | | | |
Collapse
|
29
|
Jan E, Thompson SR, Wilson JE, Pestova TV, Hellen CU, Sarnow P. Initiator Met-tRNA-independent translation mediated by an internal ribosome entry site element in cricket paralysis virus-like insect viruses. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2003; 66:285-92. [PMID: 12762030 DOI: 10.1101/sqb.2001.66.285] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- E Jan
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
| | | | | | | | | | | |
Collapse
|
30
|
Wilson JE, Powell MJ, Hoover SE, Sarnow P. Naturally occurring dicistronic cricket paralysis virus RNA is regulated by two internal ribosome entry sites. Mol Cell Biol 2000; 20:4990-9. [PMID: 10866656 PMCID: PMC85949 DOI: 10.1128/mcb.20.14.4990-4999.2000] [Citation(s) in RCA: 259] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Cricket paralysis virus is a member of a group of insect picorna-like viruses. Cloning and sequencing of the single plus-strand RNA genome revealed the presence of two nonoverlapping open reading frames, ORF1 and ORF2, that encode the nonstructural and structural proteins, respectively. We show that each ORF is preceded by one internal ribosome entry site (IRES). The intergenic IRES is located 6,024 nucleotides from the 5' end of the viral RNA and is more active than the IRES located at the 5' end of the RNA, providing a mechanistic explanation for the increased abundance of structural proteins relative to nonstructural proteins in infected cells. Mutational analysis of this intergenic-region IRES revealed that ORF2 begins with a noncognate CCU triplet. Complementarity of this CCU triplet with sequences in the IRES is important for IRES function, pointing to an involvement of RNA-RNA interactions in translation initiation. Thus, the cricket paralysis virus genome is an example of a naturally occurring, functionally dicistronic eukaryotic mRNA whose translation is controlled by two IRES elements located at the 5' end and in the middle of the mRNA. This finding argues that eukaryotic mRNAs can express multiple proteins not only by polyprotein processing, reinitiation and frameshifting but also by using multiple IRES elements.
Collapse
Affiliation(s)
- J E Wilson
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, California 94305, USA
| | | | | | | |
Collapse
|
31
|
Laubscher J, von Wechmar M. Influence of aphid lethal paralysis virus and Rhopalosiphum padi virus on aphid biology at different temperatures. J Invertebr Pathol 1992. [DOI: 10.1016/0022-2011(92)90086-j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
32
|
King LA, Moore NF. Evidence for the presence of a genome-linked protein in two insect picornaviruses, cricket paralysis and Drosophila C viruses. FEMS Microbiol Lett 1988. [DOI: 10.1111/j.1574-6968.1988.tb02908.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
33
|
Manousis T, Moore NF. Cricket Paralysis Virus, a Potential Control Agent for the Olive Fruit Fly,
Dacus oleae
Gmel. Appl Environ Microbiol 1987; 53:142-8. [PMID: 16347255 PMCID: PMC203617 DOI: 10.1128/aem.53.1.142-148.1987] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Representatives of several families of insect viruses were tested for growth and pathogenicity in the olive fruit fly,
Dacus oleae
Gmel. The viruses included nuclear polyhedrosis viruses, an iridovirus, two picornaviruses, and
Trichoplusia ni
small RNA virus (a member of the
Nudaurelia
β family), in addition to two naturally occurring viruses of the olive fruit fly. Two viruses, one of the two picornaviruses (cricket paralysis virus [CrPV] and the iridovirus (type 21 from
Heliothis armigera
), were found to replicate in adult flies. Flies which were fed on a solution containing CrPV for 1 day demonstrated a high mortality with 50% dying within 5 days and nearly 80% dying within 12 days of being fed. The virus was transmissible from infected to noninfected flies by fecal contamination. The CrPV which replicated in the infected flies was demonstrated to be the same as input virus by infection of
Drosophila melanogaster
cells and examination of the expressed viral proteins, immunoprecipitation of the virus purified from flies, and electrophoretic analysis of the structural proteins.
Collapse
Affiliation(s)
- T Manousis
- Natural Environment Research Council, Institute of Virology, Mansfield Road, Oxford OX1 3SR, United Kingdom, and Department of Biology, School of Sciences, Aristotelian University of Thessaloniki, Thessaloniki, Greece
| | | |
Collapse
|
34
|
Characterization of a picornavirus isolated from Pseudoplusia includens (Lepidoptera: Noctuidae). J Invertebr Pathol 1986. [DOI: 10.1016/0022-2011(86)90094-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
35
|
Abstract
Methods for estimating the density of virus particles after isopycnic centrifugation in cesium chloride gradients were examined. If solutions were prepared in different buffers, the standard tables relating refractive index and density, based on solutions prepared in water, did not give consistent estimates even if corrections were made for the greater refractive indices of the buffers. Depending on the method and buffer used, estimates of the density of cricket paralysis virus, an insect picornavirus, differed by as much as 0.05 g/ml. However, consistent estimates were obtained if separate regression equations were derived to relate refractive index and density for each different buffer solution of cesium chloride. This has wider implications and could account for density differences or variations in estimates reported for many other viruses.
Collapse
|
36
|
Eley SM, Nuttall PA, Moore NF. The proteins expressed in vivo and in vitro by an orbivirus of the Kemerovo serogroup isolated from Ixodes uriae ticks from St. Abb's Head, Scotland. Arch Virol 1985; 85:47-56. [PMID: 2990388 DOI: 10.1007/bf01317005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The genome of FT363 virus, a member of the Kemerovo serogroup of orbiviruses, was shown to consist of 10 segments of dsRNA. Examination of the intracellular proteins expressed by this virus in Vero cells showed the presence of 9 major and several minor products. Similar results were obtained by translation of the virus dsRNA in a rabbit reticulocyte lysate. Comparison of in vivo and in vitro products by immunoprecipitation using polyclonal FT363 ascitic fluid showed a difference in the numbers of polypeptides precipitated. The significance of these results is discussed.
Collapse
|
37
|
|
38
|
King L, Merryweather A, Moore N. Proteins expressed in vitro by two members of the Nudaurelia β family of viruses, Trichoplusia ni and Dasychira pudibunda viruses. ACTA ACUST UNITED AC 1984. [DOI: 10.1016/s0769-2617(84)80002-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
39
|
Pullin JS, Black F, King LA, Entwistle PF, Moore NF. Characterization of a Small RNA-Containing Virus in Field-Collected Larvae of the Tussock Moth,
Lymantria ninayi
, from Papua New Guinea. Appl Environ Microbiol 1984; 48:504-7. [PMID: 16346620 PMCID: PMC241556 DOI: 10.1128/aem.48.3.504-507.1984] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Field-collected larvae of the tussock moth,
Lymantria ninayi
, a major pest of exotic pines in Papua New Guinea, were found to contain a small RNA-containing virus with a diameter of 29 nm and a buoyant density of 1.32 g/ml. The RNA was single stranded, had a molecular weight of 2.8 × 10
6
, and was polyadenylated. Virion RNA stimulated an in vitro translation system, and high-molecular-weight proteins were produced. Purified virions contained four structural proteins with molecular weights of 43,000, 38,000, 33,000, and 32,000. The virus reacted positively with antisera raised against a strain of
Drosophila
C virus. The properties of this virus indicate that it should be placed in the family Picornaviridae.
Collapse
Affiliation(s)
- J S Pullin
- NERC Institute of Virology, Oxford OX1 3SR, United Kingdom
| | | | | | | | | |
Collapse
|
40
|
Reavy B, Moore NF. The gene organisation of a small RNA-containing insect virus: comparison with that of mammalian picornaviruses. Virology 1983; 131:551-4. [PMID: 6659369 DOI: 10.1016/0042-6822(83)90520-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The coding regions of an insect virus, cricket paralysis virus, have been mapped using pactamycin. The results suggest that the genome of this virus functions as a polycistronic mRNA, the structural proteins being encoded by the 5' end of the RNA in an order similar to those of mammalian picornaviruses. High-molecular-weight proteins of unknown function map at the 3' end of the genome.
Collapse
|
41
|
Heat shock used in combination with amino acid analogues and protease inhibitors to demonstrate the processing of proteins of an insect picornavirus (Drosophila C virus) in Drosophila melanogaster cells. ACTA ACUST UNITED AC 1983. [DOI: 10.1016/s0769-2617(83)80001-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
42
|
Reavy B, Moore NF. Cell-free translation of Drosophila C virus RNA: identification of a virus protease activity involved in capsid protein synthesis and further studies on in vitro processing of cricket paralysis virus specified proteins. Arch Virol 1983; 76:101-15. [PMID: 6307220 DOI: 10.1007/bf01311694] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Drosophila C virus RNA acted as mRNA in rabbit reticulocyte lysates and directed the synthesis of at least one capsid protein and a number of higher molecular weight proteins. Kinetic analysis by pulse-chase experiments showed that a number of high molecular weight products acted as precursors to the capsid protein(s). Various dilution experiments were performed which showed that the virus specified a protease activity essential for the correct processing of precursors to give the capsid protein(s). A similar result was obtained with Cricket paralysis virus, and mixing experiments showed that the protease activity specified by one virus could perform some of the cleavages resulting in the production of the capsid proteins of the other virus. Some of the cleavages involving the highest molecular weight precursors could not be performed by the protease activity of the other virus. We could find no evidence for intramolecular cleavage of the capsid precursors of either of the viruses.
Collapse
|
43
|
Hashimoto Y, Kawase S. Characteristics of structural proteins of infectious flacherie virus from the silkworm, Bombyx mori. J Invertebr Pathol 1983. [DOI: 10.1016/0022-2011(83)90237-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
44
|
|
45
|
Moore NF, Pullin JS, Crump WA, Plus N. The proteins expressed by different isolates of Drosophila C virus. Arch Virol 1982; 74:21-30. [PMID: 6297428 DOI: 10.1007/bf01320779] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Isolates of Drosophila C virus (DCV) from Drosophila flies obtained in geographically different regions were adapted to growth in Drosophila tissue culture cells. The viruses, purified from tissue culture cells, were shown to be serologically related to one of the isolates ("O" from Ouarzazate, Morocco). Analysis of the structural proteins by polyacrylamide gel electrophoresis demonstrated differences between the isolates. Labelling intracellular proteins of infected Drosophila melanogaster cells with 35S-methionine at 28 degrees C demonstrated the presence of the virus structural proteins and their immediate precursors. Raising the temperature to 37 degrees C both before and during the pulse period inhibited the processing of the high molecular weight proteins and resulted in a greater "shut-off" of host cell proteins than viral induced proteins. This allowed the precursor proteins to be compared as well as the structural proteins of the different strains. It was possible to clearly distinguish differences between the isolates on the basis of the induced proteins, although limited proteolysis of corresponding proteins showed marked similarities. Hence it is possible to distinguish between different isolates of the "same" small RNA-virus of insects from geographically different regions.
Collapse
|
46
|
Plaque purification of cricket paralysis virus using an agar overlay on Drosophila cells. J Invertebr Pathol 1982. [DOI: 10.1016/0022-2011(82)90152-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
47
|
Moore NF, Armstrong T, Green B, Brown D, Hibbin J, Kelly DC, Tinsley TW, Aloo TC. Characterization of a Nuclear Polyhedrosis Virus Isolated from Diseased Gonometa podocarpi (Lepidoptera:Lasiocampidae). Appl Environ Microbiol 1981; 42:308-16. [PMID: 16345830 PMCID: PMC244007 DOI: 10.1128/aem.42.2.308-316.1981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gonometa podocarpi is an important pest of several species of pine in East Africa, and large numbers of trees in plantations in Kenya were partially or completely defoliated by the larval stage of this insect. After the infestation in the Mt. Elgon region, large numbers of dead and moribund larvae were found on the ground. Examination of extracts of these larvae demonstrated the presence of an occluded virus. Electron microscopy of purified sectioned polyhedra demonstrated the presence of virus particles containing from 1 to 12 nucleocapsids. Purification of virus particles from polyhedra was accomplished by using alkali solubilization and sucrose gradient centrifugation. Virus particles contained 15 proteins as determined by polyacrylamide gel electrophoresis. Detergent solubilization of the virus particles released polyhedra containing one major structural protein. Electron microscopy of purified virus particles and nucleocapsids demonstrated them to be similar in structure to previously recorded nuclear polyhedrosis viruses. The viral deoxyribonucleic acid was extracted and spread for electron microscopy and was determined to have a size of approximately 80 x 10 daltons.
Collapse
Affiliation(s)
- N F Moore
- Natural Environment Research Council, Institute of Virology, Oxford OX1 3UB, England
| | | | | | | | | | | | | | | |
Collapse
|
48
|
Abstract
Cricket paralysis virus RNA acted as a messenger in a translation system and directed incorporation of 35S-methionine into protein. Polyacrylamide gel analysis of the proteins demonstrated the presence of proteins of comparable molecular weight to the viral structural proteins and also potential high molecular weight precursors.
Collapse
|
49
|
Moore NF, Pullin JS, Reavy B. Inhibition of the induction of heat shock proteins in Drosophila melanogaster cells infected with insect picornaviruses. FEBS Lett 1981; 128:93-6. [PMID: 6791964 DOI: 10.1016/0014-5793(81)81088-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
50
|
Crump WA, Moore NF. In vivo and in vitro synthesis of the proteins expressed by the RNA of black beetle virus. Arch Virol 1981; 69:131-9. [PMID: 6796033 DOI: 10.1007/bf01315156] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Black beetle virus is a small RNA virus with a single capsid protein of molecular weight congruent to 40,000. Two intracellular proteins, a presumed polymerase (molecular weight 110,000) and a protein having a molecular weight slightly greater than the capsid, were observed when infected Drosophila cells were pulsed with 35S-methionine. Viral RNA coded for the synthesis of several major proteins with molecular weights between 110,000 and 38,000 in rabbit reticulocyte lysate. Long chases of the translated products demonstrated processing of capsid protein precursors into capsid protein. Partial proteolysis demonstrated similarities in the proteins synthesised in vitro and in vivo.
Collapse
|