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Viruses Dec 2020Baculoviruses are a group of insect viruses with large circular dsDNA genomes exploited in numerous biotechnological applications, such as the biological control of... (Review)
Review
Baculoviruses are a group of insect viruses with large circular dsDNA genomes exploited in numerous biotechnological applications, such as the biological control of agricultural pests, the expression of recombinant proteins or the gene delivery of therapeutic sequences in mammals, among others. Their genomes encode between 80 and 200 proteins, of which 38 are shared by all reported species. Thanks to multi-omic studies, there is remarkable information about the baculoviral proteome and the temporality in the virus gene expression. This allows some functional elements of the genome to be very well described, such as promoters and open reading frames. However, less information is available about the transcription termination signals and, consequently, there are still imprecisions about what are the limits of the transcriptional units present in the baculovirus genomes and how is the processing of the 3' end of viral mRNA. Regarding to this, in this review we provide an update about the characteristics of DNA signals involved in this process and we contribute to their correct prediction through an exhaustive analysis that involves bibliography information, data mining, RNA structure and a comprehensive study of the core gene 3' ends from 180 baculovirus genomes.
Topics: 3' Untranslated Regions; Animals; Baculoviridae; Binding Sites; Gene Expression Regulation, Viral; Genome, Viral; Genomics; Insect Viruses; Polyadenylation; Protein Binding; RNA Processing, Post-Transcriptional; RNA, Messenger; Regulatory Sequences, Ribonucleic Acid; Transcription, Genetic; Virus Replication
PubMed: 33291215
DOI: 10.3390/v12121395 -
Viruses Nov 2011Hymenoptera is a very large and ancient insect order encompassing bees, wasps, ants and sawflies. Fossil records indicate that they existed over 200 million years ago... (Review)
Review
Hymenoptera is a very large and ancient insect order encompassing bees, wasps, ants and sawflies. Fossil records indicate that they existed over 200 million years ago and about 100 million years before the appearance of Lepidoptera. Sawflies have been major pests in many parts of the world and some have caused serious forest defoliation in North America. All baculoviruses isolated from sawflies are of the single nucleocapsids phenotype and appear to replicate in midgut cells only. This group of viruses has been shown to be excellent pest control agents and three have been registered in Canada and Britain for this purpose. Sawfly baculoviruses contain the smallest genome of all baculoviruses sequenced so far. Gene orders among sequenced sawfly baculoviruses are co-linear but this is not shared with the genomes of lepidopteran baculoviruses. One distinguishing feature among all sequenced sawfly viruses is the lack of a gene encoding a membrane fusion protein, which brought into question the role of the budded virus phenotype in Gammabaculovirus biology.
Topics: Animals; Baculoviridae; Genome, Viral; Genomics; Hymenoptera; Insect Viruses; Viral Proteins
PubMed: 22163341
DOI: 10.3390/v3112214 -
Protein Expression and Purification Feb 2023Phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2α) by eIF2α kinases is a common mechanism to regulate the initiation of...
Phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2α) by eIF2α kinases is a common mechanism to regulate the initiation of translation under stress conditions. The PK2 protein from baculovirus Autographica californica multiple nucleopolyhedrovirus (AcMNPV) binds and inhibits eIF2α kinases to ensure efficient virus propagation. The C-terminal region of PK2 shares a homology with the C-lobe of eIF2α kinases, but the N-terminal region of PK2 is unique to the orthologous proteins. In order to understand the detailed structure and function of PK2, both the full-length PK2 and its N-terminal truncated protein (PK2Δ22) were expressed as a His-tag fusion protein in Escherichia coli and purified by three steps of chromatography. Notably, the cysteine mutant, PK2 C181S/C211S, promotes the solubility and stability of the PK2 protein. The results of the size-exclusion chromatography showed that the full-length PK2 exists in both multimeric and monomeric forms, and the molecular interaction of PK2 and the eIF2α kinase domain. The purified proteins were used further to screen various conditions to obtain these crystals. Crystals of the full-length PK2 and PK2Δ22 were obtained by a sitting-drop vapour-diffusion method using lithium sulfate and PEG3350 as the precipitant, respectively. The crystal of PK2 belonged to space group P422, and diffracted X-rays to 2.7 Å resolution. The asymmetric unit contained four molecules of the protein, and the solvent content was 67.4%. Whereas, the crystal of the PK2Δ22 belonged to space group P222, diffracted X-rays to 2.8 Å resolution. The asymmetric unit contained three molecules of the protein, and the solvent content was 48.1%. The crystallographic study of the PK2 protein will provide mechanistic insights into the inhibition of eIF2α kinase by the PK2 protein, and also pave the way for the improvement of the baculovirus-based protein expression system.
Topics: X-Rays; Crystallization; Crystallography, X-Ray; Baculoviridae; Escherichia coli; Solvents
PubMed: 36229000
DOI: 10.1016/j.pep.2022.106188 -
Viruses Apr 2023Porcine deltacoronavirus (PDCoV) causes diarrhea and vomiting in neonatal piglets worldwide and has the potential for cross-species transmission. Therefore, virus-like...
Porcine deltacoronavirus (PDCoV) causes diarrhea and vomiting in neonatal piglets worldwide and has the potential for cross-species transmission. Therefore, virus-like particles (VLPs) are promising vaccine candidates because of their safety and strong immunogenicity. To the best of our knowledge, the present study reported for the first time the generation of PDCoV VLPs using a baculovirus expression vector system, and electron micrograph analyses revealed that PDCoV VLPs appeared as spherical particles with a diameter similar to that of the native virions. Furthermore, PDCoV VLPs effectively induced mice to produce PDCoV-specific IgG and neutralizing antibodies. In addition, VLPs could stimulate mouse splenocytes to produce high levels of cytokines IL-4 and IFN-γ. Moreover, the combination of PDCoV VLPs and Freund's adjuvant could improve the level of the immune response. Together, these data showed that PDCoV VLPs could effectively elicit humoral and cellular immunity in mice, laying a solid foundation for developing VLP-based vaccines to prevent PDCoV infections.
Topics: Animals; Mice; Swine; Baculoviridae; Antibodies, Neutralizing; Coronavirus; Immunity; Swine Diseases; Coronavirus Infections
PubMed: 37243181
DOI: 10.3390/v15051095 -
International Journal of Molecular... Jul 2019Hector insect toxin (AaIT), an insect-selective toxin, was identified in the venom of the scorpion . The exclusive and specific target of the toxin is the voltage-gated... (Review)
Review
Hector insect toxin (AaIT), an insect-selective toxin, was identified in the venom of the scorpion . The exclusive and specific target of the toxin is the voltage-gated sodium channels of the insect, resulting in fast excitatory paralysis and even death. Because of its strict toxic selectivity and high bioactivity, AaIT has been widely used in experiments exploring pest bio-control. Recombinant expression of AaIT in a baculovirus or a fungus can increase their virulence to insect pests and diseases vectors. Likewise, transgenic plants expressing AaIT have notable anti-insect activity. AaIT is an efficient toxin and has great potential to be used in the development of commercial insecticides.
Topics: Animals; Baculoviridae; Fungal Proteins; Fungi; Insect Control; Insecta; Protein Engineering; Scorpion Venoms; Viral Proteins; Virulence
PubMed: 31311095
DOI: 10.3390/ijms20143467 -
Viruses Feb 2019The baculovirus/insect cell system (BICS) is widely used in academia and industry to produce eukaryotic proteins for many applications, ranging from structure analysis... (Review)
Review
The baculovirus/insect cell system (BICS) is widely used in academia and industry to produce eukaryotic proteins for many applications, ranging from structure analysis to drug screening and the provision of protein biologics and therapeutics. Multi-protein complexes have emerged as vital catalysts of cellular function. In order to unlock the structure and mechanism of these essential molecular machines and decipher their function, we developed MultiBac, a BICS particularly tailored for heterologous multigene transfer and multi-protein complex production. Baculovirus is unique among common viral vectors in its capacity to accommodate very large quantities of heterologous DNA and to faithfully deliver this cargo to a host cell of choice. We exploited this beneficial feature to outfit insect cells with synthetic DNA circuitry conferring new functionality during heterologous protein expression, and developing customized MultiBac baculovirus variants in the process. By altering its tropism, recombinant baculovirions can be used for the highly efficient delivery of a customized DNA cargo in mammalian cells and tissues. Current advances in synthetic biology greatly facilitate the construction or recombinant baculoviral genomes for gene editing and genome engineering, mediated by a MultiBac baculovirus tailored to this purpose. Here, recent developments and exploits of the MultiBac system are presented and discussed.
Topics: Animals; Baculoviridae; Cloning, Molecular; DNA; Gene Editing; Gene Transfer Techniques; Genetic Vectors; Humans; Insecta; Mammals; Multiprotein Complexes; Recombinant Proteins; Viral Tropism
PubMed: 30813511
DOI: 10.3390/v11030198 -
Viruses Mar 2012Lamins are the best characterized cytoskeletal components of the cell nucleus that help to maintain the nuclear shape and participate in diverse nuclear processes... (Review)
Review
Lamins are the best characterized cytoskeletal components of the cell nucleus that help to maintain the nuclear shape and participate in diverse nuclear processes including replication or transcription. Nuclear actin is now widely accepted to be another cytoskeletal protein present in the nucleus that fulfills important functions in the gene expression. Some viruses replicating in the nucleus evolved the ability to interact with and probably utilize nuclear actin for their replication, e.g., for the assembly and transport of capsids or mRNA export. On the other hand, lamins play a role in the propagation of other viruses since nuclear lamina may represent a barrier for virions entering or escaping the nucleus. This review will summarize the current knowledge about the roles of nuclear actin and lamins in viral infections.
Topics: Actins; Animals; Baculoviridae; Cell Nucleus; Cytoskeleton; Herpesviridae; Herpesviridae Infections; Humans; Lamins; Retroviridae; Retroviridae Infections; Virus Assembly; Virus Diseases; Virus Replication
PubMed: 22590674
DOI: 10.3390/v4030325 -
Current Issues in Molecular Biology 2020The baculovirus-insect cell system has long been deployed for a variety of applications including for use as biopesticides, for recombinant protein production, transient... (Review)
Review
The baculovirus-insect cell system has long been deployed for a variety of applications including for use as biopesticides, for recombinant protein production, transient transgene expression, tissue therapy, and for vaccine production. Apart from the advantage of large-scale heterologous protein production with appropriate eukaryotic post-translational modification, foreign proteins can also be displayed on the viral envelope. This surface-display technology preserves the native multimeric structure of the protein, thereby expanding the clinical and pharmaceutical utility of the baculovirus system. Recombinant baculoviruses displaying major antigens for human or animal viruses can serve as appropriate vaccines. They can also serve as effective diagnostic platforms and various cell-based assay systems. In this review, we discuss progress in applying baculovirus surface-display, including protein display on the envelope, capsid, and occlusion bodies of baculoviruses, as well as on cells. We will also describe strategies for improvement of this biotechnological approach.
Topics: Animals; Baculoviridae; Biotechnology; Cell Line; Cell Surface Display Techniques; Genetic Vectors; Humans; Insecta; Recombinant Proteins
PubMed: 31167963
DOI: 10.21775/cimb.034.231 -
Viruses Nov 2021The fall armyworm (FAW), , is a native pest species in the Western hemisphere. Since it was first reported in Africa in 2016, FAW has spread throughout the African... (Review)
Review
The fall armyworm (FAW), , is a native pest species in the Western hemisphere. Since it was first reported in Africa in 2016, FAW has spread throughout the African continent and is now also present in several countries in Asia as well as Australia. The invasion of FAW in these areas has led to a high yield reduction in crops, leading to huge economic losses. FAW management options in the newly invaded areas are limited and mainly rely on the use of synthetic pesticides. Since there is a risk of resistance development against pesticides in addition to the negative environmental and human health impacts, other effective, sustainable, and cost-efficient control alternatives are desired. Insect pathogenic viruses fulfil these criteria as they are usually effective and highly host-specific with no significant harmful effect on beneficial insects and non-target organisms. In this review, we discuss all viruses known from FAW and their potential to be used for biological control. We specifically focus on baculoviruses and describe the recent advancements in the use of baculoviruses for biological control in the native geographic origin of FAW, and their potential use in the newly invaded areas. Finally, we identify current knowledge gaps and suggest new avenues for productive research on the use of viruses as a biopesticide against FAW.
Topics: Animals; Baculoviridae; Biological Control Agents; Crops, Agricultural; Host Specificity; Insect Viruses; Pest Control, Biological; Spodoptera
PubMed: 34835026
DOI: 10.3390/v13112220 -
Archives of Virology Jul 2006Recent evidence from genome sequence analyses demands a substantial revision of the taxonomy and classification of the family Baculoviridae. Comparisons of 29... (Review)
Review
Recent evidence from genome sequence analyses demands a substantial revision of the taxonomy and classification of the family Baculoviridae. Comparisons of 29 baculovirus genomes indicated that baculovirus phylogeny followed the classification of the hosts more closely than morphological traits that have previously been used for classification of this virus family. On this basis, dipteran- and hymenopteran-specific nucleopolyhedroviruses (NPV) should be separated from lepidopteran-specific NPVs and accommodated into different genera. We propose a new classification and nomenclature for the genera within the baculovirus family. According to this proposal the updated classification should include four genera: Alphabaculovirus (lepidopteran-specific NPV), Betabaculovirus (lepidopteran-specific Granuloviruses), Gammabaculovirus (hymenopteran-specific NPV) and Deltabaculovirus (dipteran-specific NPV).
Topics: Baculoviridae; Genome, Viral; Phylogeny; Terminology as Topic
PubMed: 16648963
DOI: 10.1007/s00705-006-0763-6