1
|
de Brito TF, Coelho VL, Cardoso MA, Brito IADA, Berni MA, Zenk FL, Iovino N, Pane A. Transovarial transmission of a core virome in the Chagas disease vector Rhodnius prolixus. PLoS Pathog 2021; 17:e1009780. [PMID: 34407148 PMCID: PMC8372912 DOI: 10.1371/journal.ppat.1009780] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 07/02/2021] [Indexed: 01/09/2023] Open
Abstract
Triatomine assassin bugs comprise hematophagous insect vectors of Trypanosoma cruzi, the causative agent of Chagas disease. Although the microbiome of these species has been investigated to some extent, only one virus infecting Triatoma infestans has been identified to date. Here, we describe for the first time seven (+) single-strand RNA viruses (RpV1-7) infecting Rhodnius prolixus, a primary vector of Chagas disease in Central and South America. We show that the RpVs belong to the Iflaviridae, Permutotetraviridae and Solemoviridae and are vertically transmitted from the mothers to the progeny via transovarial transmission. Consistent with this, all the RpVs, except RpV2 that is related to the entomopathogenic Slow bee paralysis virus, established persistent infections in our R. prolixus colony. Furthermore, we show that R. prolixus ovaries express 22-nucleotide viral siRNAs (vsiRNAs), but not viral piRNAs, that originate from the processing of dsRNA intermediates during viral replication of the RpVs. Interestingly, the permutotetraviruses and sobemoviruses display shared pools of vsiRNAs that might provide the basis for a cross-immunity system. The vsiRNAs are maternally deposited in the eggs, where they likely contribute to reduce the viral load and protect the developing embryos. Our results unveil for the first time a complex core virome in R. prolixus and begin to shed light on the RNAi-based antiviral defenses in triatomines.
Collapse
Affiliation(s)
| | - Vitor Lima Coelho
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maira Arruda Cardoso
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Mateus Antonio Berni
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fides Lea Zenk
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Nicola Iovino
- Department of Chromatin Regulation, Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Attilio Pane
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| |
Collapse
|
2
|
Abstract
Virus-like particles (VLPs) are self-assembling platforms composed of viral structural proteins. They are used for a variety of purposes, ranging from the study of virus assembly to vaccine development. VLPs can be produced in plants, bacteria, yeast, and insect and mammalian cells. The baculovirus expression system is one of the most commonly used systems for production of VLPs in eukaryotic cells. This chapter provides a brief overview of the main strategies used to generate recombinant baculoviruses and the applications of insect virus-derived VLPs in basic and applied research. It then describes detailed protocols for generation of recombinant baculoviruses, screening for their expression of VLPs in insect cells, and VLP purification.
Collapse
Affiliation(s)
- Radhika Gopal
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA
| | - Anette Schneemann
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA, USA.
| |
Collapse
|
3
|
Ferrero DS, Buxaderas M, Rodríguez JF, Verdaguer N. The Structure of the RNA-Dependent RNA Polymerase of a Permutotetravirus Suggests a Link between Primer-Dependent and Primer-Independent Polymerases. PLoS Pathog 2015; 11:e1005265. [PMID: 26625123 PMCID: PMC4666646 DOI: 10.1371/journal.ppat.1005265] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/19/2015] [Indexed: 11/18/2022] Open
Abstract
Thosea asigna virus (TaV), an insect virus belonging to the Permutatetraviridae family, has a positive-sense single-stranded RNA (ssRNA) genome with two overlapping open reading frames, encoding for the replicase and capsid proteins. The particular TaV replicase includes a structurally unique RNA-dependent RNA polymerase (RdRP) with a sequence permutation in the palm sub-domain, where the active site is anchored. This non-canonical arrangement of the RdRP palm is also found in double-stranded RNA viruses of the Birnaviridae family. Both virus families also share a conserved VPg sequence motif at the polymerase N-terminus which in birnaviruses appears to be used to covalently link a fraction of the replicase molecules to the 5’-end of the genomic segments. Birnavirus VPgs are presumed to be used as primers for replication initiation. Here we have solved the crystal structure of the TaV RdRP, the first non-canonical RdRP of a ssRNA virus, in its apo- form and bound to different substrates. The enzyme arranges as a stable dimer maintained by mutual interactions between the active site cleft of one molecule and the flexible N-terminal tail of the symmetrically related RdRP. The latter, partially mimicking the RNA template backbone, is involved in regulating the polymerization activity. As expected from previous sequence-based bioinformatics predictions, the overall architecture of the TaV enzyme shows important resemblances with birnavirus polymerases. In addition, structural comparisons and biochemical analyses reveal unexpected similarities between the TaV RdRP and those of Flaviviruses. In particular, a long loop protruding from the thumb domain towards the central enzyme cavity appears to act as a platform for de novo initiation of RNA replication. Our findings strongly suggest an unexpected evolutionary relationship between the RdRPs encoded by these distant ssRNA virus groups. RNA dependent RNA polymerases (RdRPs) are the catalytic components of the RNA replication and transcription machineries, and thus central players in the life cycle of RNA viruses. The in-depth understanding of both the structure and regulation of viral RdRPs displaying different replication-transcription strategies might provide essential clues for an effective control of virus propagation. The characterization of the first non-canonical RdRP of a positive-stranded RNA virus, the permutotetravirus Thosea asigna virus, has unveiled two essential elements controlling polymerization activity: (i) the protein N-terminus that invades the central cleft of the neighboring RdRP molecule, thus stabilizing a dimeric form of the enzyme with partially occluded template binding channels; and (ii) a long loop protruding towards the catalytic cavity which harbors the binding site of incoming nucleotides, thus providing a platform for de novo replication initiation. The close structural and functional resemblance between this enzyme and flaviviral RdRPs strongly suggests the existence of an unexpected evolutionary link between these two distant virus groups.
Collapse
Affiliation(s)
- Diego S. Ferrero
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Barcelona, Spain
- Centro Nacional de Biotecnología, CSIC, Madrid, Spain
| | - Mònica Buxaderas
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Barcelona, Spain
| | - José F. Rodríguez
- Centro Nacional de Biotecnología, CSIC, Madrid, Spain
- * E-mail: (JFR); (NV)
| | - Núria Verdaguer
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Barcelona, Spain
- * E-mail: (JFR); (NV)
| |
Collapse
|
4
|
Assembly and maturation of a T = 4 quasi-equivalent virus is guided by electrostatic and mechanical forces. Viruses 2014; 6:3348-62. [PMID: 25153346 PMCID: PMC4147699 DOI: 10.3390/v6083348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Revised: 08/15/2014] [Accepted: 08/18/2014] [Indexed: 11/17/2022] Open
Abstract
Nudaurelia capensis w virus (NωV) is a eukaryotic RNA virus that is well suited for the study of virus maturation. The virus initially assembles at pH 7.6 into a marginally stable 480-Å procapsid formed by 240 copies of a single type of protein subunit. During maturation, which occurs during apoptosis at pH 5.0, electrostatic forces guide subunit trajectories into a robust 410-Å virion that is buttressed by subunit associated molecular switches. We discuss the competing factors in the virus capsid of requiring near-reversible interactions during initial assembly to avoid kinetic traps, while requiring robust stability to survive in the extra-cellular environment. In addition, viruses have a variety of mechanisms to deliver the genome, which must remain off while still inside the infected cell, yet turn on under the proper conditions of infection. We conclude that maturation is the process that provides a solution to these conflicting requirements through a program that is encoded in the procapsid and that leads to stability and infectivity.
Collapse
|
5
|
Liu F, Wu X, Li L, Liu Z, Wang Z. Use of baculovirus expression system for generation of virus-like particles: successes and challenges. Protein Expr Purif 2013; 90:104-16. [PMID: 23742819 PMCID: PMC7128112 DOI: 10.1016/j.pep.2013.05.009] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 05/13/2013] [Accepted: 05/15/2013] [Indexed: 11/10/2022]
Abstract
A brief overview of principles and applications of BES. Generation of VLPs using BES. Major properties of BES: promoting generation of VLPs. Bioprocess considerations for generation of VLPs.
The baculovirus expression system (BES) has been one of the versatile platforms for the production of recombinant proteins requiring multiple post-translational modifications, such as folding, oligomerization, phosphorylation, glycosylation, acylation, disulfide bond formation and proteolytic cleavage. Advances in recombinant DNA technology have facilitated application of the BES, and made it possible to express multiple proteins simultaneously in a single infection and to produce multimeric proteins sharing functional similarity with their natural analogs. Therefore, the BES has been used for the production of recombinant proteins and the construction of virus-like particles (VLPs), as well as for the development of subunit vaccines, including VLP-based vaccines. The VLP, which consists of one or more structural proteins but no viral genome, resembles the authentic virion but cannot replicate in cells. The high-quality recombinant protein expression and post-translational modifications obtained with the BES, along with its capacity to produce multiple proteins, imply that it is ideally suited to VLP production. In this article, we critically review the pros and cons of using the BES as a platform to produce both enveloped and non-enveloped VLPs.
Collapse
Affiliation(s)
- Fuxiao Liu
- National Research Center for Exotic Animal Diseases, China Animal Health and Epidemiology Center, Qingdao, Shandong 266032, China
| | | | | | | | | |
Collapse
|
6
|
Abstract
Over the last three decades, virus-like particles (VLPs) have evolved to become a widely accepted technology, especially in the field of vaccinology. In fact, some VLP-based vaccines are currently used as commercial medical products, and other VLP-based products are at different stages of clinical study. Several remarkable advantages have been achieved in the development of VLPs as gene therapy tools and new nanomaterials. The analysis of published data reveals that at least 110 VLPs have been constructed from viruses belonging to 35 different families. This review therefore discusses the main principles in the cloning of viral structural genes, the relevant host systems and the purification procedures that have been developed. In addition, the methods that are used to characterize the structural integrity, stability, and components, including the encapsidated nucleic acids, of newly synthesized VLPs are analyzed. Moreover, some of the modifications that are required to construct VLP-based carriers of viral origin with defined properties are discussed, and examples are provided.
Collapse
Affiliation(s)
- Andris Zeltins
- Latvian Biomedical Research and Study Centre, Ratsupites 1, Riga 1067, Latvia.
| |
Collapse
|
7
|
Ferrero D, Buxaderas M, Rodriguez JF, Verdaguer N. Purification, crystallization and preliminary X-ray diffraction analysis of the RNA-dependent RNA polymerase from Thosea asigna virus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2012; 68:1263-6. [PMID: 23027763 PMCID: PMC3490467 DOI: 10.1107/s1744309112037529] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 08/31/2012] [Indexed: 11/11/2022]
Abstract
Thosea asigna virus (TaV) is a positive-sense, single-stranded RNA (ssRNA) virus that belongs to the Permutotetravirus genera within the recently created Permutotetraviridae family. The genome of TaV consists of an RNA segment of about 5.700 nucleotides with two open reading frames, encoding for the replicase and capsid protein. The particular TaV replicase does not contain N7-methyl transferase and helicase domains but includes a structurally unique RNA-dependent RNA polymerase (RdRp) with a sequence permutation in the domain where the active site is anchored. This architecture is also found in double-stranded RNA viruses of the Birnaviridae family. Here we report the purification and preliminary crystallographic studies TaV RdRp. The enzyme was crystallized by the sitting-drop vapour diffusion method using PEG 8K and lithium sulfate as precipitants. Two different crystal forms were obtained: native RdRp crystallized in space group P2(1)2(1)2 and diffracts up to 2.1 Å and the RdRp-Lu(3+) derivative co-crystals belong to the C222(1) space group, diffracting to 3.0 Å resolution. The structure of TaV RdRp represents the first structure of a non-canonical RdRp from ssRNA viruses.
Collapse
Affiliation(s)
- Diego Ferrero
- Centro Nacional de Biotecnología, CSIC, Calle Darwin No. 3, Madrid, 28049, Spain
| | - Mònica Buxaderas
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Baldiri i Reixac 10, Barcelona, 08028, Spain
| | - José F. Rodriguez
- Centro Nacional de Biotecnología, CSIC, Calle Darwin No. 3, Madrid, 28049, Spain
| | - Núria Verdaguer
- Institut de Biologia Molecular de Barcelona, CSIC, Parc Científic de Barcelona, Baldiri i Reixac 10, Barcelona, 08028, Spain
| |
Collapse
|
8
|
Walter CT, Pringle FM, Nakayinga R, de Felipe P, Ryan MD, Ball LA, Dorrington RA. Genome organization and translation products of Providence virus: insight into a unique tetravirus. J Gen Virol 2010; 91:2826-35. [PMID: 20702652 DOI: 10.1099/vir.0.023796-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Providence virus (PrV) is a member of the family Tetraviridae, a family of small, positive-sense, ssRNA viruses that exclusively infect lepidopteran insects. PrV is the only known tetravirus that replicates in tissue culture. We have analysed the genome and characterized the viral translation products, showing that PrV has a monopartite genome encoding three ORFs: (i) p130, unique to PrV and of unknown function; (ii) p104, which contains a read-through stop signal, producing an N-terminal product of 40 kDa (p40) and (iii) the capsid protein precursor (p81). There are three 2A-like processing sequences: one at the N terminus of p130 (PrV-2A₁) and two more (PrV-2A₂ and PrV-2A₃) at the N terminus of p81. Metabolic radiolabelling identified viral translation products corresponding to all three ORFs in persistently infected cells and showed that the read-through stop in p104 and PrV-2A₃ in p81 are functional in vivo and these results were confirmed by in vitro translation experiments. The RNA-dependent RNA polymerase domain of the PrV replicase is phylogenetically most closely related to members of the families Tombusviridae and Umbraviridae rather than to members of the family Tetraviridae. The unique genome organization, translational control systems and phylogenetic relationship with the replicases of (+ve) plant viruses lead us to propose that PrV represents a novel family of small insect RNA viruses, distinct from current members of the family Tetraviridae.
Collapse
Affiliation(s)
- Cheryl T Walter
- Dept of Biochemistry, Microbiology and Biotechnology, Rhodes University, Grahamstown 6140, South Africa
| | | | | | | | | | | | | |
Collapse
|
9
|
Euprosterna elaeasa virus genome sequence and evolution of the Tetraviridae family: emergence of bipartite genomes and conservation of the VPg signal with the dsRNA Birnaviridae family. Virology 2009; 397:145-54. [PMID: 19954807 DOI: 10.1016/j.virol.2009.10.042] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2009] [Revised: 10/08/2009] [Accepted: 10/28/2009] [Indexed: 11/21/2022]
Abstract
The Tetraviridae is a family of non-enveloped positive-stranded RNA insect viruses that is defined by the T=4 symmetry of virions. We report the complete Euprosterna elaeasa virus (EeV) genome sequence of 5698 nt with no poly(A) tail and two overlapping open reading frames, encoding the replicase and capsid precursor, with approximately 67% amino acid identity to Thosea asigna virus (TaV). The N-terminally positioned 17 kDa protein is released from the capsid precursor by a NPGP motif. EeV has 40 nm non-enveloped isometric particles composed of 58 and 7 kDa proteins. The 3'-end of TaV/EeV is predicted to form a conserved pseudoknot. Replicases of TaV and EeV include a newly delineated VPg signal mediating the protein priming of RNA synthesis in dsRNA Birnaviridae. Results of rooted phylogenetic analysis of replicase and capsid proteins are presented to implicate recombination between monopartite tetraviruses, involving autonomization of a sgRNA, in the emergence of bipartite tetraviruses. They are also used to revise the Tetraviridae taxonomy.
Collapse
|
10
|
Ambrose RL, Lander GC, Maaty WS, Bothner B, Johnson JE, Johnson KN. Drosophila A virus is an unusual RNA virus with a T=3 icosahedral core and permuted RNA-dependent RNA polymerase. J Gen Virol 2009; 90:2191-200. [PMID: 19474243 DOI: 10.1099/vir.0.012104-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The vinegar fly, Drosophila melanogaster, is a popular model for the study of invertebrate antiviral immune responses. Several picorna-like viruses are commonly found in both wild and laboratory populations of D. melanogaster. The best-studied and most pathogenic of these is the dicistrovirus Drosophila C virus. Among the uncharacterized small RNA viruses of D. melanogaster, Drosophila A virus (DAV) is the least pathogenic. Historically, DAV has been labelled as a picorna-like virus based on its particle size and the content of its RNA genome. Here, we describe the characterization of both the genome and the virion structure of DAV. Unexpectedly, the DAV genome was shown to encode a circular permutation in the palm-domain motifs of the RNA-dependent RNA polymerase. This arrangement has only been described previously for a subset of viruses from the double-stranded RNA virus family Birnaviridae and the T=4 single-stranded RNA virus family Tetraviridae. The 8 A (0.8 nm) DAV virion structure computed from cryo-electron microscopy and image reconstruction indicates that the virus structural protein forms two discrete domains within the capsid. The inner domain is formed from a clear T=3 lattice with similarity to the beta-sandwich domain of tomato bushy stunt virus, whilst the outer domain is not ordered icosahedrally, but forms a cage-like structure that surrounds the core domain. Taken together, this indicates that DAV is highly divergent from previously described viruses.
Collapse
Affiliation(s)
- Rebecca L Ambrose
- School of Biological Sciences, The University of Queensland, Brisbane, Australia
| | | | | | | | | | | |
Collapse
|
11
|
Taylor DJ, Speir JA, Reddy V, Cingolani G, Pringle FM, Ball LA, Johnson JE. Preliminary x-ray characterization of authentic providence virus and attempts to express its coat protein gene in recombinant baculovirus. Arch Virol 2005; 151:155-65. [PMID: 16211330 DOI: 10.1007/s00705-005-0637-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Accepted: 04/01/2005] [Indexed: 11/27/2022]
Abstract
Providence Virus (PrV) is a non-envoloped, T = 4 icosahedral beta-tetravirus that undergoes autocatalytic cleavage of its coat protein precursor after capsid assembly. This is also a well characterized function of Nudaurelia capensis omega virus (NomegaV), a member of the related omegatetraviruses, whose x-ray structure has been determined. Virus-like particle (VLP) production of PrV in a recombinant baculovirus expression system was attempted to obtain high VLP yields for comparison of structural and autocatalytic active site properties between these virus groups. This resulted in insoluble aggregates of PrV coat protein even though NomegaV VLPs have been successfully produced in the same system. Betatetraviruses may be more dependent on compartmentalization and availability of their full-length genome for proper folding and assembly. However, crystals were grown of limited quantities of authentic PrV produced in cell culture and a partial X-ray data set collected to 3.8 A resolution. The virus particle position and orientation in the unit cell was determined by space group consideration and rotation function analysis. A phasing model, based on NomegaV, was developed to initiate the structure solution of PrV.
Collapse
Affiliation(s)
- D J Taylor
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92037, USA
| | | | | | | | | | | | | |
Collapse
|
12
|
Yi F, Zhang J, Yu H, Liu C, Wang J, Hu Y. Isolation and identification of a new tetravirus from Dendrolimus punctatus larvae collected from Yunnan Province, China. J Gen Virol 2005; 86:789-796. [PMID: 15722541 DOI: 10.1099/vir.0.80543-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In this study, Dendrolimus punctatus tetravirus (DpTV) has been identified as a new member of the genus Omegatetravirus of the family Tetraviridae that may be related serologically to Nudaurelia capensis omega virus (NomegaV). DpTV particles are isometric, with a diameter of about 40 nm and a buoyant density of 1.281 g cm(-3) in CsCl. The virus has two capsid proteins (of 62 500 and 6800 Da) and two single-stranded RNA molecules (RNA1 and RNA2), which are 5492 and 2490 nt long, respectively. RNA1 has a large open reading frame (ORF) encoding a polypeptide of 180 kDa; RNA2 contains two partially overlapping ORFs encoding polypeptides of 17 and 70 kDa. The 180 kDa protein, which contains consensus motifs of a putative methyltransferase, helicase and RNA-dependent RNA polymerase, shows significant similarity to those of other tetraviruses. The 17 kDa protein is a PEST (Pro/Glu/Ser/Thr) protein of unknown function. The 70 kDa protein is the coat protein precursor and is predicted to be cleaved at an Asn-Phe site located after residue 570. The 70 kDa protein shows 86 and 66 % identity to its homologues in NomegaV and Helicoverpa armigera stunt virus, respectively. Secondary-structure analysis revealed that the RNAs of DpTV have tRNA-like structures at their 3' termini.
Collapse
Affiliation(s)
- Fuming Yi
- Laboratory of Insect Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Jiamin Zhang
- Laboratory of Insect Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Haiyang Yu
- Laboratory of Insect Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Chuanfeng Liu
- Laboratory of Insect Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Junping Wang
- Laboratory of Insect Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| | - Yuanyang Hu
- Laboratory of Insect Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China
| |
Collapse
|
13
|
Palucha A, Loniewska A, Satheshkumar S, Boguszewska-Chachulska AM, Umashankar M, Milner M, Haenni AL, Savithri HS. Virus-like particles: models for assembly studies and foreign epitope carriers. PROGRESS IN NUCLEIC ACID RESEARCH AND MOLECULAR BIOLOGY 2005; 80:135-68. [PMID: 16164974 PMCID: PMC7119358 DOI: 10.1016/s0079-6603(05)80004-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Virus‐like particles (VLPs), formed by the structural elements of viruses, have received considerable attention over the past two decades. The number of reports on newly obtained VLPs has grown proportionally with the systems developed for the expression of these particles. The chapter outlines the recent achievements in two important fields of research brought about by the availability of VLPs produced in a foreign host. These are: (1) The requirements for VLP assembly and (2) the use of VLPs as carriers for foreign epitopes. VLP technology is a rapidly advancing domain of molecular and structural biology. Extensive progress in VLP studies was achieved as the insect cell based protein production system was developed. This baculovirus expression system has many advantages for the synthesis of viral structural proteins resulting in the formation of VLPs. It allows production of large amounts of correctly folded proteins while also providing cell membranes that can serve as structural elements for enveloped viruses. These features give us the opportunity to gain insights into the interactions and requirements accompanying VLP formation that are similar to the assembly events occurring in mammalian cells. Other encouraging elements are the ability to easily scale up the system and the simplicity of purification of the assembled VLPs. The growing number of VLPs carrying foreign protein fragments on their surface and studies on the successful assembly of these chimeric molecules is a promising avenue towards the development of a new technology, in which the newly designed VLPs will be directed to particular mammalian cell types by exposing specific binding domains. The progress made in modeling the surface of VLPs makes them to date the best candidates for the design of delivery systems that can efficiently reach their targets.
Collapse
Affiliation(s)
- Andrzej Palucha
- Institute of Biochemistry and Biophysics, Pawinskiego 5a, 02-106 Warszawa, Poland
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Oña A, Luque D, Abaitua F, Maraver A, Castón JR, Rodríguez JF. The C-terminal domain of the pVP2 precursor is essential for the interaction between VP2 and VP3, the capsid polypeptides of infectious bursal disease virus. Virology 2004; 322:135-42. [PMID: 15063123 DOI: 10.1016/j.virol.2004.01.025] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2003] [Revised: 01/22/2004] [Accepted: 01/22/2004] [Indexed: 11/26/2022]
Abstract
The interaction between the infectious bursal disease virus (IBDV) capsid proteins VP2 and VP3 has been analyzed in vivo using baculovirus expression vectors. Data presented here demonstrate that the 71-amino acid C-terminal-specific domain of pVP2, the VP2 precursor, is essential for the establishment of the VP2-VP3 interaction. Additionally, we show that coexpression of the pVP2 and VP3 polypeptides from independent genes results in the assembly of virus-like particles (VLPs). This observation demonstrates that these two polypeptides contain the minimal information required for capsid assembly, and that this process does not require the presence of the precursor polyprotein.
Collapse
Affiliation(s)
- Ana Oña
- Department of Biología Molecular y Celular, Centro Nacional de Biotecnología, Cantoblanco, 28049 Madrid, Spain
| | | | | | | | | | | |
Collapse
|
15
|
Pringle FM, Johnson KN, Goodman CL, McIntosh AH, Ball LA. Providence virus: a new member of the Tetraviridae that infects cultured insect cells. Virology 2003; 306:359-70. [PMID: 12642108 DOI: 10.1016/s0042-6822(02)00052-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We identified a new member of the Tetraviridae, Providence virus (PrV), persistently infecting a midgut cell line derived from the corn earworm (Helicoverpa zea). Virus purified from these cells also productively infected a H. zea fat body cell line, and a cell line from whole embryos of the beet armyworm, Spodoptera exigua. PrV is thus the first tetravirus shown to replicate in cell culture. PrV virions are isometric particles composed of two structural proteins (60 and 7.4 kDa) that encapsidate both the genomic (6.4 kb) and the subgenomic (2.5 kb) RNAs. The monopartite organization of the PrV genome resembles that of Nudaurelia beta virus and Thosea asigna virus, members of the genus Betatetravirus. The predicted sequence of the PrV structural proteins demonstrates homology to tetraviruses in both genera. The infectivity of PrV for cultured cells uniquely permitted examination of tetravirus RNA and protein synthesis during synchronous infection. The discovery of PrV greatly facilitates studies of tetravirus molecular biology.
Collapse
Affiliation(s)
- Fiona M Pringle
- Department of Microbiology, University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL 35294, USA
| | | | | | | | | |
Collapse
|
16
|
Gorbalenya AE, Pringle FM, Zeddam JL, Luke BT, Cameron CE, Kalmakoff J, Hanzlik TN, Gordon KHJ, Ward VK. The palm subdomain-based active site is internally permuted in viral RNA-dependent RNA polymerases of an ancient lineage. J Mol Biol 2002; 324:47-62. [PMID: 12421558 PMCID: PMC7127740 DOI: 10.1016/s0022-2836(02)01033-1] [Citation(s) in RCA: 188] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Template-dependent polynucleotide synthesis is catalyzed by enzymes whose core component includes a ubiquitous alphabeta palm subdomain comprising A, B and C sequence motifs crucial for catalysis. Due to its unique, universal conservation in all RNA viruses, the palm subdomain of RNA-dependent RNA polymerases (RdRps) is widely used for evolutionary and taxonomic inferences. We report here the results of elaborated computer-assisted analysis of newly sequenced replicases from Thosea asigna virus (TaV) and the closely related Euprosterna elaeasa virus (EeV), insect-specific ssRNA+ viruses, which revise a capsid-based classification of these viruses with tetraviruses, an Alphavirus-like family. The replicases of TaV and EeV do not have characteristic methyltransferase and helicase domains, and include a putative RdRp with a unique C-A-B motif arrangement in the palm subdomain that is also found in two dsRNA birnaviruses. This circular motif rearrangement is a result of migration of approximately 22 amino acid (aa) residues encompassing motif C between two internal positions, separated by approximately 110 aa, in a conserved region of approximately 550 aa. Protein modeling shows that the canonical palm subdomain architecture of poliovirus (ssRNA+) RdRp could accommodate the identified sequence permutation through changes in backbone connectivity of the major structural elements in three loop regions underlying the active site. This permutation transforms the ferredoxin-like beta1alphaAbeta2beta3alphaBbeta4 fold of the palm subdomain into the beta2beta3beta1alphaAalphaBbeta4 structure and brings beta-strands carrying two principal catalytic Asp residues into sequential proximity such that unique structural properties and, ultimately, unique functionality of the permuted RdRps may result. The permuted enzymes show unprecedented interclass sequence conservation between RdRps of true ssRNA+ and dsRNA viruses and form a minor, deeply separated cluster in the RdRp tree, implying that other, as yet unidentified, viruses may employ this type of RdRp. The structural diversification of the palm subdomain might be a major event in the evolution of template-dependent polynucleotide polymerases in the RNA-protein world.
Collapse
Key Words
- rna viruses
- rna polymerases
- evolution
- protein permutation
- ancient palm subdomain
- aa, amino acid
- cd, conserved domain
- eev, euprosterna elaeasa virus
- ibdv, infectious bursal disease virus
- ipnvj, infectious pancreatic necrosis virus strain jasper
- pv, poliovirus
- tav, thosea asigna virus
- dsrna, double-stranded rna
- ssrna+, positive-stranded rna
- rdrp, rna-dependent rna polymerase
- hmm, hidden markov model
- orf, open reading frames
- nt, nucleotide
- tdpp, template-dependent polynucleotide polymerase
Collapse
Affiliation(s)
- Alexander E Gorbalenya
- Advanced Biomedical Computing Center, Science Applications International Corporation/National Cancer Institute, P.O. Box B, Frederick, MD 21702-1201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|