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Gao W, Liu X, Gao X, Wu T, Wei S, Zhang Z, Zhang H, Li Y. Genome characteristics and the ODV proteome of a second distinct alphabaculovirus from Spodoptera litura. BMC Genomics 2024; 25:91. [PMID: 38253995 PMCID: PMC10804782 DOI: 10.1186/s12864-024-09989-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 01/08/2024] [Indexed: 01/24/2024] Open
Abstract
BACKGROUND Spodoptera litura is a harmful pest that feeds on more than 80 species of plants, and can be infected and killed by Spodoptera litura nucleopolyhedrovirus (SpltNPV). SpltNPV-C3 is a type C SpltNPV clone, that was observed and collected in Japan. Compared with type A or type B SpltNPVs, SpltNPV-C3 can cause the rapid mortality of S. litura larvae. METHODS In this study, occlusion bodies (OBs) and occlusion-derived viruses (ODVs) of SpltNPV-C3 were purified, and OBs were observed by scanning electron microscopy (SEM). ODVs were observed under a transmission electron microscope (TEM). RESULTS Both OBs and ODVs exhibit morphological characteristics typical of nucleopolyhedroviruses (NPVs).The genome of SpltNPV-C3 was sequenced and analyzed; the total length was 148,634 bp (GenBank accession 780,426,which was submitted as SpltNPV-II), with a G + C content of 45%. A total of 149 predicted ORFs were found. A phylogenetic tree of 90 baculoviruses was constructed based on core baculovirus genes. LC‒MS/MS was used to analyze the proteins of SpltNPV-C3; 34 proteins were found in the purified ODVs, 15 of which were core proteins. The structure of the complexes formed by per os infectivity factors 1, 2, 3 and 4 (PIF-1, PIF-2, PIF-3 and PIF-4) was predicted with the help of the AlphaFold multimer tool and predicted conserved sequences in PIF-3. SpltNPV-C3 is a valuable species because of its virulence, and the analysis of its genome and proteins in this research will be beneficial for pest control efforts.
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Affiliation(s)
- Weisong Gao
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Xingjian Liu
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Xintao Gao
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Tong Wu
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Shuang Wei
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Zhifang Zhang
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China
| | - Huan Zhang
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, 100101, Beijing, China.
| | - Yinü Li
- National Key Laboratory of Agricultural Microbiology, Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, 100081, Beijing, China.
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In silico tertiary structure prediction and evolutionary analysis of two DNA-binding proteins (DBP-1 and DBP-2) from Hyposidra talaca nucleopolyhedrovirus (HytaNPV). Biologia (Bratisl) 2021. [DOI: 10.2478/s11756-020-00665-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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3
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Huang YF, Chen TH, Chang ZT, Wang TC, Lee SJ, Kim JC, Kim JS, Chiu KP, Nai YS. Genomic sequencing of Troides aeacus nucleopolyhedrovirus (TraeNPV) from golden birdwing larvae (Troides aeacus formosanus) to reveal defective Autographa californica NPV genomic features. BMC Genomics 2019; 20:419. [PMID: 31133070 PMCID: PMC6537400 DOI: 10.1186/s12864-019-5713-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 04/17/2019] [Indexed: 11/25/2022] Open
Abstract
Background The golden birdwing butterfly (Troides aeacus formosanus) is a rarely observed species in Taiwan. Recently, a typical symptom of nuclear polyhedrosis was found in reared T. aeacus larvae. From the previous Kimura-2 parameter (K-2-P) analysis based on the nucleotide sequence of three genes in this isolate, polh, lef-8 and lef-9, the underlying virus did not belong to any known nucleopolyhedrovirus (NPV) species. Therefore, this NPV was provisionally named “TraeNPV”. To understand this NPV, the nucleotide sequence of the whole TraeNPV genome was determined using next-generation sequencing (NGS) technology. Results The genome of TraeNPV is 125,477 bp in length with 144 putative open reading frames (ORFs) and its GC content is 40.45%. A phylogenetic analysis based on the 37 baculoviral core genes suggested that TraeNPV is a Group I NPV that is closely related to Autographa californica nucleopolyhedrovirus (AcMNPV). A genome-wide analysis showed that TraeNPV has some different features in its genome compared with other NPVs. Two novel ORFs (Ta75 and Ta139), three truncated ORFs (pcna, he65 and bro) and one duplicated ORF (38.7 K) were found in the TraeNPV genome; moreover, there are fewer homologous regions (hrs) than there are in AcMNPV, which shares eight hrs within the TraeNPV genome. TraeNPV shares similar genomic features with AcMNPV, including the gene content, gene arrangement and gene/genome identity, but TraeNPV lacks 15 homologous ORFs from AcMNPV in its genome, such as ctx, host cell-specific factor 1 (hcf-1), PNK/PNL, vp15, and apsup, which are involved in the auxiliary functions of alphabaculoviruses. Conclusions Based on these data, TraeNPV would be clarified as a new NPV species with defective AcMNPV genomic features. The precise relationship between TraeNPV and other closely related NPV species were further investigated. This report could provide comprehensive information on TraeNPV for evolutionary insights into butterfly-infected NPV. Electronic supplementary material The online version of this article (10.1186/s12864-019-5713-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yu-Feng Huang
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Tzu-Han Chen
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Zih-Ting Chang
- Department of Biotechnology and Animal Science, National Ilan University, Yilan, Taiwan
| | - Tai-Chuan Wang
- Department of Entomology, National Taiwan University, Taipei, Taiwan
| | - Se Jin Lee
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, South Korea
| | - Jong Cheol Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, South Korea
| | - Jae Su Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, South Korea
| | - Kuo-Ping Chiu
- Genomics Research Center, Academia Sinica, Taipei, Taiwan
| | - Yu-Shin Nai
- Department of Entomology, National Chung Hsing University, Taichung, Taiwan.
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4
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Xu W, Fan Y, Wang H, Feng M, Wu X. Bombyx mori nucleopolyhedrovirus F-like protein Bm14 affects the morphogenesis and production of occlusion bodies and the embedding of ODVs. Virology 2019; 526:61-71. [DOI: 10.1016/j.virol.2018.10.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 10/09/2018] [Accepted: 10/09/2018] [Indexed: 12/11/2022]
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5
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Zhu Z, Wang J, Wang Q, Yin F, Liu X, Hou D, Zhang L, Liu H, Li J, Arif BM, Wang H, Deng F, Hu Z, Wang M. Genome Characteristics of the Cyclophragma Undans Nucleopolyhedrovirus: A Distinct Species in Group I of Alphabaculovirus. Virol Sin 2018; 33:359-368. [PMID: 30155853 DOI: 10.1007/s12250-018-0047-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 07/16/2018] [Indexed: 11/26/2022] Open
Abstract
The Cyclophragma undans nucleopolyhedrovirus (CyunNPV), a potential pest control agent, was isolated from Cyclophragma undans (Lepidoptera: Lasiocampidae), an important forest pest. In the present study, we performed detailed genome analysis of CyunNPV and compared its genome to those of other Group I alphabaculoviruses. Sequencing of the CyunNPV genome using the Roche 454 sequencing system generated 142,900 bp with a G + C content of 45%. Genome analysis predicted a total of 147 hypothetical open reading frames comprising 38 baculoviral core genes, 24 lepidopteran baculovirus conserved genes, nine Group I Alphabaculovirus conserved genes, 71 common genes, and five genes that are unique to CyunNPV. In addition, the genome contains 13 homologous repeated sequences (hrs). Phylogenetic analysis groups CyunNPV under a distinct branch within clade "a" of Group I in the genus Alphabaculovirus. Unlike other members of Group I, CyunNPV harbors only nine of the 11 genes previously determined to be specific to Group I viruses. Furthermore, the CyunNPV lacks the tyrosine phosphatase gene and the ac30 gene. The CyunNPV F-like protein contains two insertions of continuous polar amino acids, one at the conventional fusion peptide and a second insertion at the pre-transmembrane domain. The insertions are likely to affect the fusion function and suggest an evolutionary process that led to inactivation of the F-like protein. The above findings imply that CyunNPV is a distinct species under Group I Alphabaculovirus.
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Affiliation(s)
- Zheng Zhu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Jun Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Qianran Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Feifei Yin
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Xiaoping Liu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Dianhai Hou
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Lei Zhang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Haizhou Liu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Jiang Li
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Basil M Arif
- Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste Marie, ON, P6A 2E5, Canada
| | - Hualin Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Fei Deng
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Zhihong Hu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | - Manli Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China.
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6
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Wang J, Hou D, Wang Q, Kuang W, Zhang L, Li J, Shen S, Deng F, Wang H, Hu Z, Wang M. Genome analysis of a novel Group I alphabaculovirus obtained from Oxyplax ochracea. PLoS One 2018; 13:e0192279. [PMID: 29390020 PMCID: PMC5794183 DOI: 10.1371/journal.pone.0192279] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Accepted: 01/18/2018] [Indexed: 02/03/2023] Open
Abstract
Oxyplax ochracea (Moore) is a pest that causes severe damage to a wide range of crops, forests and fruit trees. The complete genome sequence of Oxyplax ochracea nucleopolyhedrovirus (OxocNPV) was determined using a Roche 454 pyrosequencing system. OxocNPV has a double-stranded DNA (dsDNA) genome of 113,971 bp with a G+C content of 31.1%. One hundred and twenty-four putative open reading frames (ORFs) encoding proteins of >50 amino acids in length and with minimal overlapping were predicted, which covered 92% of the whole genome. Six baculoviral typical homologous regions (hrs) were identified. Phylogenetic analysis and gene parity plot analysis showed that OxocNPV belongs to clade “a” of Group I alphabaculoviruses, and it seems to be close to the most recent common ancestor of Group I alphabaculoviruses. Three unique ORFs (with no homologs in the National Center for Biotechnology Information database) were identified. Interestingly, OxocNPV lacks three auxiliary genes (lef7, ie-2 and pcna) related to viral DNA replication and RNA transcription. In addition, OxocNPV has significantly different sequences for several genes (including ie1 and odv-e66) in comparison with those of other baculoviruses. However, three dimensional structure prediction showed that OxocNPV ODV-E66 contain the conserved catalytic residues, implying that it might possess polysaccharide lyase activity as AcMNPV ODV-E66. All these unique features suggest that OxocNPV represents a novel species of the Group I alphabaculovirus lineage.
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Affiliation(s)
- Jun Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Dianhai Hou
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- School of Bioscience and Technology, Weifang Medical University, Weifang, China
| | - Qianran Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Wenhua Kuang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Lei Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Jiang Li
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Shu Shen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Fei Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Hualin Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Zhihong Hu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Manli Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
- * E-mail:
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Protein composition analysis of polyhedra matrix of Bombyx mori nucleopolyhedrovirus (BmNPV) showed powerful capacity of polyhedra to encapsulate foreign proteins. Sci Rep 2017; 7:8768. [PMID: 28821766 PMCID: PMC5562830 DOI: 10.1038/s41598-017-08987-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Accepted: 07/14/2017] [Indexed: 11/23/2022] Open
Abstract
Polyhedra can encapsulate other proteins and have potential applications as protein stabilizers. The extremely stable polyhedra matrix may provide a platform for future engineered micro-crystal devices. However, the protein composition of the polyhedra matrix remains largely unknown. In this study, the occlusion-derived virus (ODV)-removed BmNPV polyhedra matrix fraction was subjected to SDS-PAGE and then an LC-ESI-MS/MS analysis using a Thermo Scientific Q Exactive mass spectrometer. In total, 28 host and 91 viral proteins were identified. The host components were grouped into one of six categories, i.e., chaperones, ubiquitin and related proteins, host helicases, cytoskeleton-related proteins, RNA-binding proteins and others, according to their predicted Pfam domain(s). Most viral proteins may not be essential for polyhedra assembly, as evidenced by studies in the literature showing that polyhedra formation occurs in the nucleus upon the disruption of individual genes. The structural role of these proteins in baculovirus replication will be of significant interest in future studies. The immobilization of enhanced green fluorescent protein (eGFP) into the polyhedra by fusing with the C-terminus of BM134 that is encoded by open reading frame (ORF) 134 suggested that the polyhedra had a powerful capacity to trap foreign proteins, and BM134 was a potential carrier for incorporating proteins of interest into the polyhedra.
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8
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Wang M, Shen S, Wang H, Hu Z, Becnel J, Vlak JM. Deltabaculoviruses encode a functional type I budded virus envelope fusion protein. J Gen Virol 2017; 98:847-852. [PMID: 28452294 DOI: 10.1099/jgv.0.000745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Envelope fusion proteins (F proteins) are major constituents of budded viruses (BVs) of alpha- and betabaculoviruses (Baculoviridae) and are essential for the systemic infection of insect larvae and insect cell culture. An f homologue gene is absent in gammabaculoviruses. Here we characterized the putative F-homologue (Cuni-F), encoded by (ORF) 104 of Culex nigripalpus nucleopolyhedrovirus (CuniNPV), the only deltabaculovirus member. When expressed alone, this protein seems to locate on the cell surface and is able to induce cell-cell fusion. When expressed by an alphabaculovirus (Autographa california nucleopolyhedrovirus), it was found to be incorporated into BVs. Western blot analyses detected the uncleaved Cuni-F0 and the furin-cleaved F1 forms. Treatment of infected cells with tunicamycin showed that Cuni-F contains N-glycans. Mutagenesis analysis identified the canonical furin cleavage site 126RARR129 as being responsible for the cleavage of Cuni-F in insect cells. The collective evidence suggests that CuniNPV encodes a functional F protein.
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Affiliation(s)
- Manli Wang
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands.,Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, PR China
| | - Shu Shen
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, PR China
| | - Hualin Wang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, PR China
| | - Zhihong Hu
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, PR China
| | - James Becnel
- Center for Medical, Agricultural and Veterinary Entomology, CMAVE (USDA, ARS), Gainesville, Florida, USA
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Wageningen, The Netherlands
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9
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Genome Sequencing and Analysis of Catopsilia pomona nucleopolyhedrovirus: A Distinct Species in Group I Alphabaculovirus. PLoS One 2016; 11:e0155134. [PMID: 27166956 PMCID: PMC4864199 DOI: 10.1371/journal.pone.0155134] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2016] [Accepted: 04/25/2016] [Indexed: 12/16/2022] Open
Abstract
The genome sequence of Catopsilia pomona nucleopolyhedrovirus (CapoNPV) was determined by the Roche 454 sequencing system. The genome consisted of 128,058 bp and had an overall G+C content of 40%. There were 130 hypothetical open reading frames (ORFs) potentially encoding proteins of more than 50 amino acids and covering 92% of the genome. Among all the hypothetical ORFs, 37 baculovirus core genes, 23 lepidopteran baculovirus conserved genes and 10 genes conserved in Group I alphabaculoviruses were identified. In addition, the genome included regions of 8 typical baculoviral homologous repeat sequences (hrs). Phylogenic analysis showed that CapoNPV was in a distinct branch of clade “a” in Group I alphabaculoviruses. Gene parity plot analysis and overall similarity of ORFs indicated that CapoNPV is more closely related to the Group I alphabaculoviruses than to other baculoviruses. Interesting, CapoNPV lacks the genes encoding the fibroblast growth factor (fgf) and ac30, which are conserved in most lepidopteran and Group I baculoviruses, respectively. Sequence analysis of the F-like protein of CapoNPV showed that some amino acids were inserted into the fusion peptide region and the pre-transmembrane region of the protein. All these unique features imply that CapoNPV represents a member of a new baculovirus species.
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10
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Shen S, Wang M, Li X, Li S, van Oers MM, Vlak JM, Braakman I, Hu Z, Deng F, Wang H. Mutational and functional analysis of N-linked glycosylation of envelope fusion protein F of Helicoverpa armigera nucleopolyhedrovirus. J Gen Virol 2016; 97:988-999. [PMID: 26769631 DOI: 10.1099/jgv.0.000404] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The envelope fusion (F) protein of baculoviruses is a heavily N-glycosylated protein that plays a significant role in the virus infection cycle. N-Linked glycosylation of virus envelope glycoprotein is important for virus envelope glycoprotein folding and its function in general. There are six predicted N-glycosylation sites in the F (HaF) protein of Helicoverpa armigera nucleopolyhedrovirus (HearNPV). The N-glycosylation site located in the F(2) subunit (N104) of HaF has been identified and functionally characterized previously (Long et al., 2007). In this study, the other five potential N-glycosylation sites located in the HaF1 subunit, namely, N293, N361, N526, N571 and N595, were analysed extensively to examine their N-glycosylation and relative importance to the function of HaF. The results showed that four of these five potential glycosylation sites in the F(1) subunit, N293, N361, N526 and N571, were N-glycosylated in F proteins of mature HearNPV budded viruses (BVs) but that N595 was not. In general, the conserved site N526 was critical to the functioning of HaF, as absence of N-glycosylation of N526 reduced the efficiency of HaF folding and trafficking, consequently decreased fusogenicity and modified the subcellular localization of HaF proteins, and thus impaired virus production and infectivity. The absence of N-glycosylation at other individual sites was found to have different effects on the fusogenicity and subcelluar distribution of HaF proteins in HzAM1 cells. In summary, N-glycosylation plays comprehensive roles in HaF function and virus infectivity, which is further discussed.
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Affiliation(s)
- Shu Shen
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina
| | - Manli Wang
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina
| | - Xin Li
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina.,Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | - Shufen Li
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina
| | | | - Just M Vlak
- Laboratory of Virology, Wageningen University, The Netherlands
| | - Ineke Braakman
- Cellular Protein Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, The Netherlands
| | - Zhihong Hu
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina
| | - Fei Deng
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina
| | - Hualin Wang
- State Key Laboratory of Virology, and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PRChina
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11
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Wang Q, Bosch BJ, Vlak JM, van Oers MM, Rottier PJ, van Lent JWM. Budded baculovirus particle structure revisited. J Invertebr Pathol 2015; 134:15-22. [PMID: 26743500 PMCID: PMC7127228 DOI: 10.1016/j.jip.2015.12.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 11/24/2015] [Accepted: 12/01/2015] [Indexed: 01/13/2023]
Abstract
Baculovirus budded virion ultrastructure has been revisited using cryo-electron microscopy. The now well-preserved virions have a remarkable elongated, ovoid shape and large lateral space between nucleocapsid and the intact envelope. Consistent with previous findings using classical electron microscopy the nucleocapsid has a distinctive cap and base structure interacting tightly with the envelope. Most spikes are densely clustered at the two apical ends of the virion. Using cryo-electron microscopy the viral envelope appeared to contain two layers with a total thickness of ≈6–7 nm, which is significantly thicker than a usual biological membrane (<4 nm). The spikes on the surface of AcMNPV BVs appear distinctly different from those of SeMNPV. Based on our observations we propose a new structural model of baculovirus budded virions.
Baculoviruses are a group of enveloped, double-stranded DNA insect viruses with budded (BV) and occlusion-derived (ODV) virions produced during their infection cycle. BVs are commonly described as rod shaped particles with a high apical density of protein extensions (spikes) on the lipid envelope surface. However, due to the fragility of BVs the conventional purification and electron microscopy (EM) staining methods considerably distort the native viral structure. Here, we use cryo-EM analysis to reveal the near-native morphology of two intensively studied baculoviruses, Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) and Spodoptera exigua MNPV (SeMNPV), as models for BVs carrying GP64 and F as envelope fusion protein on the surface. The now well-preserved AcMNPV and SeMNPV BV particles have a remarkable elongated, ovoid shape leaving a large, lateral space between nucleocapsid (NC) and envelope. Consistent with previous findings the NC has a distinctive cap and base structure interacting tightly with the envelope. This tight interaction may explain the partial retaining of the envelope on both ends of the NC and the disappearance of the remainder of the BV envelope in the negative-staining EM images. Cryo-EM also reveals that the viral envelope contains two layers with a total thickness of ≈6–7 nm, which is significantly thicker than a usual biological membrane (<4 nm) as measured by X-ray scanning. Most spikes are densely clustered at the two apical ends of the virion although some envelope proteins are also found more sparsely on the lateral regions. The spikes on the surface of AcMNPV BVs appear distinctly different from those of SeMNPV. Based on our observations we propose a new near-native structural model of baculovirus BVs.
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Affiliation(s)
- Qiushi Wang
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands; Virology Division, Department of Infectious Disease and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Berend-Jan Bosch
- Virology Division, Department of Infectious Disease and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Monique M van Oers
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - Peter J Rottier
- Virology Division, Department of Infectious Disease and Immunology, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | - Jan W M van Lent
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
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Krejmer M, Skrzecz I, Wasag B, Szewczyk B, Rabalski L. The genome of Dasychira pudibunda nucleopolyhedrovirus (DapuNPV) reveals novel genetic connection between baculoviruses infecting moths of the Lymantriidae family. BMC Genomics 2015; 16:759. [PMID: 26449402 PMCID: PMC4599791 DOI: 10.1186/s12864-015-1963-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 09/29/2015] [Indexed: 11/10/2022] Open
Abstract
Background DapuNPV (Dasychira pudibunda nucleopolyhedrovirus), presented in this report, belongs to Alphabaculovirus group Ib. Its full, newly sequenced genome shows close relationship to baculovirus OpMNPV isolated from douglas-fir tussock moth Orgyia pseudotsugata. Baculovirus DapuNPV is a natural limiter of pale tussock moth Dasychira pudibunda L. (syn. Calliteara pudibunda L.)(Lepidoptera, Lymantriidae), which can occur in a form of an outbreak on many species of deciduous trees and may cause significant economic losses in the forests. Methods Late instars dead larvae of pale tussock moth were mechanically homogenized and polyhedra were purified during series of ultracentrifugation. Viral DNA was extarcted and sequenced using Miseq Illumina platform. 294,902 paired reads were used for de novo assembling. Genome annotation, multiple allingment to others baculoviruses and phylogegentic analises were perform with the use of multiple bioinformatic tools like: Glimmer3, HMMER web server, Geneious 7 and MEGA6. Results The genome of DapuNPV is 136,761 bp long with AT pairs content 45.6 %. The predicted number of encoded putative open reading frames (ORFs) is 161 and six of them demonstrate low or no homology to ORFs previously found in baculoviruses. DapuNPV genome shows very high similarity to OpMNPV in a nucleotide sequence (91.1 % of identity) and gene content (150 homologous ORFs), though some major differences (e.g. lack of he65 in OpMNPV) have also been noted. Conclusions Similarly to other members of the Baculoviridae family, DapuNPV baculovirus possesses highly conserved core genes. Among them, there is a second copy of occluded derived virus envelope 27 protein (odv-e27), which was previously found only in a member of Alphabaculovirus group II – LyxyMNPV (Lymantria xylina MNPV). Surprisingly enough, DapuNPV and LyxyMNPV genomes share also another feature. Phylogenetic analysis of chitin binding family protein (cbpl) indicates significant similarity of those two baculoviruses from distinct evolutionary groups which infect the same hosts from Lymantriidae. The ubiquitin like family gene (ubil), which has not been described until now, is another characteristic component of DapuNPV genome. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1963-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Martyna Krejmer
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Kladki Str. 24, Poland.
| | - Iwona Skrzecz
- Forest Research Institute, Department of Forest Protection, 05-090, Raszyn, Braci Lesnej Str. 3, Sekocin Stary, Poland.
| | - Bartosz Wasag
- Department of Biology and Genetics, Medical University of Gdansk, 80-211, Gdansk, Debinki Str. 1, Poland.
| | - Boguslaw Szewczyk
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Kladki Str. 24, Poland.
| | - Lukasz Rabalski
- Department of Recombinant Vaccines, Intercollegiate Faculty of Biotechnology University of Gdansk and Medical University of Gdansk, 80-822, Gdansk, Kladki Str. 24, Poland.
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Yin F, Zhu Z, Liu X, Hou D, Wang J, Zhang L, Wang M, Kou Z, Wang H, Deng F, Hu Z. The Complete Genome of a New Betabaculovirus from Clostera anastomosis. PLoS One 2015; 10:e0132792. [PMID: 26168260 PMCID: PMC4500397 DOI: 10.1371/journal.pone.0132792] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 06/19/2015] [Indexed: 11/18/2022] Open
Abstract
Clostera anastomosis (Lepidoptera: Notodontidae) is a defoliating forest insect pest. Clostera anastomosis granulovirus-B (ClasGV-B) belonging to the genus Betabaculovirus of family Baculoviridae has been used for biological control of the pest. Here we reported the full genome sequence of ClasGV-B and compared it to other previously sequenced baculoviruses. The circular double-stranded DNA genome is 107,439 bp in length, with a G+C content of 37.8% and contains 123 open reading frames (ORFs) representing 93% of the genome. ClasGV-B contains 37 baculovirus core genes, 25 lepidopteran baculovirus specific genes, 19 betabaculovirus specific genes, 39 other genes with homologues to baculoviruses and 3 ORFs unique to ClasGV-B. Hrs appear to be absent from the ClasGV-B genome, however, two non-hr repeats were found. Phylogenetic tree based on 37 core genes from 73 baculovirus genomes placed ClasGV-B in the clade b of betabaculoviruses and was most closely related to Erinnyis ello GV (ErelGV). The gene arrangement of ClasGV-B also shared the strongest collinearity with ErelGV but differed from Clostera anachoreta GV (ClanGV), Clostera anastomosis GV-A (ClasGV-A, previously also called CaLGV) and Epinotia aporema GV (EpapGV) with a 20 kb inversion. ClasGV-B genome contains three copies of polyhedron envelope protein gene (pep) and phylogenetic tree divides the PEPs of betabaculoviruses into three major clades: PEP-1, PEP-2 and PEP/P10. ClasGV-B also contains three homologues of P10 which all harbor an N-terminal coiled-coil domain and a C-terminal basic sequence. ClasGV-B encodes three fibroblast growth factor (FGF) homologues which are conserved in all sequenced betabaculoviruses. Phylogenetic analysis placed these three FGFs into different groups and suggested that the FGFs were evolved at the early stage of the betabaculovirus expansion. ClasGV-B is different from previously reported ClasGV-A and ClanGV isolated from Notodontidae in sequence and gene arrangement, indicating the virus is a new notodontid betabaculovirus.
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Affiliation(s)
- Feifei Yin
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
- School of Tropical and Laboratory Medicine, Hainan Medical University, Haikou, 571101, PR China
| | - Zheng Zhu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Xiaoping Liu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Dianhai Hou
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Jun Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Lei Zhang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Manli Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Zheng Kou
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Hualin Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Fei Deng
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
| | - Zhihong Hu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, PR China
- * E-mail:
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Yang M, Huang C, Qian DD, Li LL. Functional characterization of Autographa californica multiple nucleopolyhedrovirus gp16 ( ac130 ). Virology 2014; 464-465:341-352. [DOI: 10.1016/j.virol.2014.07.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 05/07/2014] [Accepted: 07/18/2014] [Indexed: 10/24/2022]
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Autographa californica multiple nucleopolyhedrovirus orf132 encodes a nucleocapsid-associated protein required for budded-virus and multiply enveloped occlusion-derived virus production. J Virol 2014; 88:12586-98. [PMID: 25142609 DOI: 10.1128/jvi.01313-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
UNLABELLED Autographa californica multiple nucleopolyhedrovirus orf132 (named ac132) has homologs in all genome-sequenced group I nucleopolyhedroviruses. Its role in the viral replication cycle is unknown. In this study, ac132 was shown to express a protein of around 28 kDa, which was determined to be associated with the nucleocapsids of both occlusion-derived virus and budded virus. Confocal microscopy showed that AC132 protein appeared in central region of the nucleus as early as 12 h postinfection with the virus. It formed a ring zone at the periphery of the nucleus by 24 h postinfection. To investigate its role in virus replication, ac132 was deleted from the viral genome by using a bacmid system. In the Sf9 cell culture transfected by the ac132 knockout bacmid, infection was restricted to single cells, and the titer of infectious budded virus was reduced to an undetectable level. However, viral DNA replication and the expression of late genes vp39 and odv-e25 and a reporter gene under the control of the very late gene p10 promoter were unaffected. Electron microscopy showed that nucleocapsids, virions, and occlusion bodies were synthesized in the cells transfected by an ac132 knockout bacmid, but the formation of the virogenic stroma and occlusion bodies was delayed, the numbers of enveloped nucleocapsids were reduced, and the occlusion bodies contained mainly singly enveloped nucleocapsids. AC132 was found to interact with envelope protein ODV-E18 and the viral DNA-binding protein P6.9. The data from this study suggest that ac132 possibly plays an important role in the assembly and envelopment of nucleocapsids. IMPORTANCE To our knowledge, this is the first report on a functional analysis of ac132. The data presented here demonstrate that ac132 is required for production of the budded virus and multiply enveloped occlusion-derived virus of Autographa californica multiple nucleopolyhedrovirus. This article reveals unique phenotypic changes induced by ac132 deletion on the virus and multiple new findings on ac132.
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Yin F, Wang M, Tan Y, Deng F, Vlak JM, Hu Z, Wang H. Identification and functional analysis of inter-subunit disulfide bonds of the F protein of Helicoverpa armigera nucleopolyhedrovirus. J Gen Virol 2014; 95:2820-2830. [PMID: 25114029 DOI: 10.1099/vir.0.068122-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The major envelope fusion protein F of the budded virus of baculoviruses consists of two disulfide-linked subunits: an N-terminal F2 subunit and a C-terminal, membrane-anchored F1 subunit. There is one cysteine in F2 and there are 15 cysteines in F1, but their role in disulfide linking is largely unknown. In this study, the inter- and intra-subunit disulfide bonds of the Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV) F protein were analysed by site-directed mutagenesis. Results indicated that in a functional F protein, an inter-subunit disulfide bond exists between amino acids C108 (F2) and C241 (F1). When C241 was mutated, an alternative disulfide bond was formed between C108 and C232, rendering F non-functional. No inter-subunit bridge was observed in a double C232/C241 mutant of F1. C403 was not involved in the formation of inter-subunit disulfide bonding, but mutation of this amino acid decreased viral infectivity significantly, suggesting that it might be involved in intra-subunit disulfide bonds. The influence of reductant [tris(2-carboxyethyl) phosphine (TCEP)] and free-thiol inhibitors [4-acetamido-4'-maleimidylstilbene 2,2'-disulfonic acid (AMS) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB)] on the infectivity of HearNPV was tested. The results indicated that TCEP greatly decreased the infection of HzAm1 cells by HearNPV. In contrast, AMS and DTNB had no inhibitory effect on viral infectivity. The data suggested that free thiol/disulfide isomerization was not likely to play a role in viral entry and infectivity.
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Affiliation(s)
- Feifei Yin
- School of Tropical and Laboratory Medicine, Hainan Medical University, Haikou 571101, PR China.,State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences (CAS), Wuhan 430071, PR China
| | - Manli Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences (CAS), Wuhan 430071, PR China
| | - Ying Tan
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences (CAS), Wuhan 430071, PR China
| | - Fei Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences (CAS), Wuhan 430071, PR China
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Zhihong Hu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences (CAS), Wuhan 430071, PR China
| | - Hualin Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences (CAS), Wuhan 430071, PR China
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Paul A, Hasan A, Rodes L, Sangaralingam M, Prakash S. Bioengineered baculoviruses as new class of therapeutics using micro and nanotechnologies: principles, prospects and challenges. Adv Drug Deliv Rev 2014; 71:115-30. [PMID: 24503281 DOI: 10.1016/j.addr.2014.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 01/08/2014] [Accepted: 01/13/2014] [Indexed: 12/15/2022]
Abstract
Designing a safe and efficient gene delivery system is required for success of gene therapy trials. Although a wide variety of viral, non-viral and polymeric nanoparticle based careers have been widely studied, the current gene delivery vehicles are limited by their suboptimal, non-specific therapeutic efficacy and acute immunological reactions, leading to unwanted side effects. Recently, there has been a growing interest in insect-cell-originated baculoviruses as gene delivery vehicles for diverse biomedical applications. Specifically, the emergence of diverse types of surface functionalized and bioengineered baculoviruses is posed to edge over currently available gene delivery vehicles. This is primarily because baculoviruses are comparatively non-pathogenic and non-toxic as they cannot replicate in mammalian cells and do not invoke any cytopathic effect. Moreover, emerging advanced studies in this direction have demonstrated that hybridizing the baculovirus surface with different kinds of bioactive therapeutic molecules, cell-specific targeting moieties, protective polymeric grafts and nanomaterials can significantly improve the preclinical efficacy of baculoviruses. This review presents a comprehensive overview of the recent advancements in the field of bioengineering and biotherapeutics to engineer baculovirus hybrids for tailored gene therapy, and articulates in detail the potential and challenges of these strategies for clinical realization. In addition, the article illustrates the rapid evolvement of microfluidic devices as a high throughput platform for optimizing baculovirus production and treatment conditions.
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Affiliation(s)
- Arghya Paul
- Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering and Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Québec H3A 2B4, Canada; Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA
| | - Anwarul Hasan
- Harvard-MIT Division of Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Cambridge, MA 02139, USA
| | - Laetitia Rodes
- Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering and Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Québec H3A 2B4, Canada
| | - Mugundhine Sangaralingam
- Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering and Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Québec H3A 2B4, Canada
| | - Satya Prakash
- Biomedical Technology and Cell Therapy Research Laboratory, Department of Biomedical Engineering and Artificial Cells and Organs Research Centre, Faculty of Medicine, McGill University, 3775 University Street, Montreal, Québec H3A 2B4, Canada.
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Chen H, Li M, Huang G, Mai W, Chen K, Zhou Y. Bombyx mori nucleopolyhedrovirus ORF101 encodes a budded virus envelope associated protein. Curr Microbiol 2014; 69:158-63. [PMID: 24677040 DOI: 10.1007/s00284-014-0570-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 03/01/2014] [Indexed: 11/29/2022]
Abstract
Orf101 (Bm101) of Bombyx mori nucleopolyhedrovirus (BmNPV) is a highly conserved gene in lepidopteran nucleopolyhedroviruses, but its function remains unknown. In this study, Bm101 was characterized. Transcripts of Bm101 were detected from 24 through 96 h post infection (h p.i.) by RT-PCR. The corresponding protein was also detected from 24 to 96 h p.i. in BmNPV-infected BmN cells by Western blot analysis using a polyclonal antibody against Bm101. Western blot assay of occlusion-derived virus and budded virus (BV) preparations revealed that Bm101 encodes a 28-kDa structural protein that is associated with BV and is located in the envelope fraction of budded virions. In addition, confocal analysis showed that the protein was localized in the cytosol and cytoplasmic membrane in virus-infected cells. In conclusion, the available data suggest that Bm101 is a functional ORF of BmNPV and encodes a protein expressed in the late stage of the infection cycle that is associated with the BV envelope.
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Affiliation(s)
- Huiqing Chen
- Institute of Life Sciences, Jiangsu University, 301# Xuefu Road, Zhenjiang, 212013, China,
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Zhu Z, Yin F, Liu X, Hou D, Wang J, Zhang L, Arif B, Wang H, Deng F, Hu Z. Genome sequence and analysis of Buzura suppressaria nucleopolyhedrovirus: a group II Alphabaculovirus. PLoS One 2014; 9:e86450. [PMID: 24475121 PMCID: PMC3901692 DOI: 10.1371/journal.pone.0086450] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Accepted: 12/10/2013] [Indexed: 12/15/2022] Open
Abstract
The genome of Buzura suppressaria nucleopolyhedrovirus (BusuNPV) was sequenced by 454 pyrosequencing technology. The size of the genome is 120,420 bp with 36.8% G+C content. It contains 127 hypothetical open reading frames (ORFs) covering 90.7% of the genome and includes the 37 conserved baculovirus core genes, 84 genes found in other baculoviruses, and 6 unique ORFs. No typical baculoviral homologous repeats (hrs) were present but the genome contained a region of repeated sequences. Gene Parity Plots revealed a 28.8 kb region conserved among the alpha- and beta-baculoviruses. Overall comparisons of BusuNPV to other baculoviruses point to a distinct species in group II Alphabaculovirus.
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Affiliation(s)
- Zheng Zhu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Feifei Yin
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Xiaoping Liu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Dianhai Hou
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Jun Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Lei Zhang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Basil Arif
- Canadian Forest Service, Great Lakes Forestry Centre, Sault Ste Marie, Ontario, Canada
| | - Hualin Wang
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Fei Deng
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Zhihong Hu
- State Key Laboratory of Virology and China Center for Virus Culture Collection, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
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Jo YH, Patnaik BB, Kang SW, Chae SH, Oh S, Kim DH, Noh MY, Seo GW, Jeong HC, Noh JY, Jeong JE, Hwang HJ, Ko K, Han YS, Lee YS. Analysis of the genome of a Korean isolate of the Pieris rapae granulovirus enabled by its separation from total host genomic DNA by pulse-field electrophoresis. PLoS One 2013; 8:e84183. [PMID: 24391907 PMCID: PMC3877225 DOI: 10.1371/journal.pone.0084183] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 11/12/2013] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Most traditional genome sequencing projects involving viruses include the culture and purification of the virus particles. However, purification of virions may yield insufficient material for traditional sequencing. The electrophoretic method described here provides a strategy whereby the genomic DNA of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) could be recovered in sufficient amounts for sequencing by purifying it directly from total host DNA by pulse-field gel electrophoresis (PFGE). METHODOLOGY/PRINCIPAL FINDINGS The total genomic DNA of infected P. rapae was embedded in agarose plugs, treated with restriction nuclease and methylase, and then PFGE was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the purified viral DNA. The double-stranded circular genome of PiraGV-K was found to encode 120 open reading frames (ORFs), which covered 92% of the sequence. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF 11), involved in the liquefaction of the host, were found in the genome. CONCLUSIONS/SIGNIFICANCE The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the electrophoretic method. The method appears to be generally applicable to the analysis of genomes of large viruses.
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Affiliation(s)
- Yong Hun Jo
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Bharat Bhusan Patnaik
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Se Won Kang
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea
| | | | - Seunghan Oh
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Dong Hyun Kim
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Mi Young Noh
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Gi Won Seo
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Heon Cheon Jeong
- Hampyeong County Insect Institute, Hampyeong County Agricultural Technology Center, Hampyeong, South Korea
| | - Ju Young Noh
- Hampyeong County Insect Institute, Hampyeong County Agricultural Technology Center, Hampyeong, South Korea
| | - Ji Eun Jeong
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea
| | - Hee Ju Hwang
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea
| | - Kisung Ko
- Department of Medicine, Medical Research Institute, College of Medicine, Chung-Ang University, Seoul, South Korea
| | - Yeon Soo Han
- Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea
| | - Yong Seok Lee
- Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea
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Unraveling the entry mechanism of baculoviruses and its evolutionary implications. J Virol 2013; 88:2301-11. [PMID: 24335309 DOI: 10.1128/jvi.03204-13] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The entry of baculovirus budded virus into host cells is mediated by two distinct types of envelope fusion proteins (EFPs), GP64 and F protein. Phylogenetic analysis suggested that F proteins were ancestral baculovirus EFPs, whereas GP64 was acquired by progenitor group I alphabaculovirus more recently and may have stimulated the formation of the group I lineage. This study was designed to experimentally recapitulate a possible major step in the evolution of baculoviruses. We demonstrated that the infectivity of an F-null group II alphabaculovirus (Helicoverpa armigera nucleopolyhedrovirus [HearNPV]) can be functionally rescued by coinsertion of GP64 along with the nonfusogenic F(def) (furin site mutated HaF) from HearNPV. Interestingly, HearNPV enters cells by endocytosis and, less efficiently, by direct membrane fusion at low pH. However, this recombinant HearNPV coexpressing F(def) and GP64 mimicked group I virus not only in its EFP composition but also in its abilities to enter host cells via low-pH-triggered direct fusion pathway. Neutralization assays indicated that the nonfusogenic F proteins contribute mainly to binding to susceptible cells, while GP64 contributes to fusion. Coinsertion of GP64 with an F-like protein (Ac23) from group I virus led to efficient rescue of an F-null group II virus. In summary, these recombinant viruses and their entry modes are considered to resemble an evolutionary event of the acquisition of GP64 by an ancestral group I virus and subsequent adaptive inactivation of the original F protein. The study described here provides the first experimental evidence to support the hypothesis of the evolution of baculovirus EFPs.
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Yin F, Wang M, Tan Y, Deng F, Vlak JM, Hu Z, Wang H. Betabaculovirus F proteins showed different efficiencies when rescuing the infectivity of gp64-null Autographa californica nucleopolyhedrovirus. Virology 2012; 436:59-66. [PMID: 23245471 DOI: 10.1016/j.virol.2012.10.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 08/18/2012] [Accepted: 10/09/2012] [Indexed: 11/18/2022]
Abstract
The Agrotis segetum granulovirus (AgseGV) F protein was previously identified as the first betabaculovirus F protein with functional homology to Autographa californica nucleopolyhedrovirus (AcMNPV) GP64. In the current study, F proteins from Xestia c-nigrum granulovirus (XecnGV), Cydia pomonella granulovirus (CpGV), Phthorimaea operculella granulovirus (PhopGV), Choristoneura occidentalis granulovirus (ChocGV) and Plutella xylostella GV (PlxyGV) were studied for their ability to rescue the infectivity of gp64-null AcMNPV. Our results showed that most studied betabaculovirus F proteins could replace the function of AcMNPV GP64, however, their efficiencies to rescue the infectivity of gp64-null AcMNPV were substantially different. PlxyF, although fusogenic, was the only protein that failed to substitute the function of AcMNPV GP64. Further studies using Sf9(0p1D) cell line showed that PlxyF appeared to be properly incorporated into AcMNPV virions and underwent correct post-translational cleavage and N-linked glycosylation. However, the gp64-null AcMNPV containing PlxyF could not be propagated in either Sf9 or P. xylostella cells.
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Affiliation(s)
- Feifei Yin
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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Salem TZ, Zhang F, Thiem SM. Reduced expression of Autographa californica nucleopolyhedrovirus ORF34, an essential gene, enhances heterologous gene expression. Virology 2012; 435:225-38. [PMID: 23131351 DOI: 10.1016/j.virol.2012.10.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Revised: 08/15/2012] [Accepted: 10/15/2012] [Indexed: 12/22/2022]
Abstract
Autographa californica multiple nucleopolyhedrovirus ORF34 is part of a transcriptional unit that includes ORF32, encoding a viral fibroblast growth factor (FGF) and ORF33. We identified ORF34 as a candidate for deletion to improve protein expression in the baculovirus expression system based on enhanced reporter gene expression in an RNAi screen of virus genes. However, ORF34 was shown to be an essential gene. To explore ORF34 function, deletion (KO34) and rescue bacmids were constructed and characterized. Infection did not spread from primary KO34 transfected cells and supernatants from KO34 transfected cells could not infect fresh Sf21 cells whereas the supernatant from the rescue bacmids transfection could recover the infection. In addition, budded viruses were not observed in KO34 transfected cells by electron microscopy, nor were viral proteins detected from the transfection supernatants by western blots. These demonstrate that ORF34 is an essential gene with a possible role in infectious virus production.
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Affiliation(s)
- Tamer Z Salem
- Department of Entomology, Michigan State University, East Lansing, MI 48824, USA
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Shen S, Gan Y, Wang M, Hu Z, Wang H, Deng F. Incorporation of GP64 into Helicoverpa armigera nucleopolyhedrovirus enhances virus infectivity in vivo and in vitro. J Gen Virol 2012; 93:2705-2711. [PMID: 22956736 DOI: 10.1099/vir.0.046458-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The envelope fusion proteins of baculoviruses, glycoprotein GP64 from group I nucleopolyhedrovirus (NPV) or the F protein from group II NPV and granulovirus, are essential for baculovirus morphogenesis and infectivity. The F protein is considered the ancestral baculovirus envelope fusion protein, while GP64 is a more recent evolutionary introduction into baculoviruses and exhibits higher fusogenic activity than the F protein. Each of the fusion proteins is required by the respective virus to spread infection within larval tissues. A recombinant Helicoverpa armigera NPV (HearNPV) expressing GP64 from Autographa californica multiple nucleopolyhedrovirus, vHaBac-gp64-egfp, was constructed, which still retained the native F protein, and its infectivity was assayed in vivo and in vitro. Analyses by one-step growth curve to determine viral titre and by quantitative PCR to determine viral DNA copy number showed that vHaBac-gp64-egfp was more infectious in vitro than the control, vHaBac-egfp. The polyhedrin gene (polh) was reintroduced into the recombinant viruses and bioassays showed that vHaBac-gp64-polh accelerated the mortality of infected larvae compared with the vHaBac-egfp-polh control, and the LC(50) (median lethal concentration) of vHaBac-gp64-polh was reduced to approximately 20 % of that of vHaBac-egfp-polh. Therefore, incorporation of GP64 into HearNPV budded virions improved virus infectivity both in vivo and in vitro. The construction of this bivalent virus with a more efficient fusion protein could improve the use of baculoviruses in different areas such as gene therapy and biocontrol.
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Affiliation(s)
- Shu Shen
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Yinyin Gan
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Manli Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Zhihong Hu
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Hualin Wang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Fei Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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Functional analysis of the Autographa californica multiple nucleopolyhedrovirus GP64 terminal fusion loops and interactions with membranes. J Virol 2012; 86:9617-28. [PMID: 22740400 DOI: 10.1128/jvi.00813-12] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) glycoprotein GP64 is the major envelope protein of the budded virus (BV). GP64 is a class III fusion protein that mediates BV attachment to the cell surface and low-pH-triggered membrane fusion between the BV envelope and the endosome membrane during entry. Class III fusion proteins contain terminal looped structures that are believed to interact with membranes. To examine the functions of 3 loops found at the apex of the GP64 postfusion structure, we generated 2-alanine substitutions that scanned the two so-called fusion loops (loop 1 and loop 2) plus an adjacent loop structure (loop 3) that is closely attached to loop 2 and is also found at the apex of the GP64 postfusion structure. We identified essential residues from Y75 to T86 (loop 1) and N149 to H156 (loop 2) that are required for fusion activity, but no essential residues in loop 3. Further analysis revealed that critical fusion loop residues fall within two groups that are associated with either membrane merger (hemifusion) or fusion pore expansion. We next examined the interactions of soluble GP64 proteins and BV with membranes composed of various phospholipids. BV interacted directly with small unilamellar vesicles (SUVs) comprised of phospholipids phosphatidylcholine and phosphatidic acid (PC/PA) or phosphatidylcholine and phosphatidylserine (PC/PS) under neutral and acidic pH. We also examined the interactions of soluble GP64 constructs containing substitutions of the most hydrophobic residues within each of the two fusion loops. We found that a 2-residue substitution in either single loop (loop 1 [positions 81 and 82] or loop 2 [positions 153 and 154]) was not sufficient to substantially reduce the GP64-liposome interaction, but the same substitutions in both fusion loops severely reduced the GP64-liposome association at neutral pH. These results suggest that critical hydrophobic residues in both fusion loops may be involved in the interaction of GP64 with host cellular membranes and direct GP64-membrane interactions may represent a receptor-binding step prior to a low-pH-triggered conformational change.
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Navarro-Cerrillo G, Ferré J, de Maagd RA, Herrero S. Functional interactions between members of the REPAT family of insect pathogen-induced proteins. INSECT MOLECULAR BIOLOGY 2012; 21:335-342. [PMID: 22404489 DOI: 10.1111/j.1365-2583.2012.01139.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Studies on the transcriptional response to pathogens in the insect larval gut have shown the regulation of several genes after the infection. Repat (REsponse to PAThogens) genes were first identified in Spodoptera exigua midgut as being up-regulated in response to the exposure to Bacillus thuringiensis toxins and baculovirus. Recently, new members of the REPAT family showed a constitutive up-regulation in a B. thuringiensis-resistant population. Based on a yeast two-hybrid screening, we have detected the interaction of REPAT1 with other members of the REPAT family, leading to the discovery of a new member: REPAT8. The functional role of this interaction was shown by following the changes of the subcellular localization of REPAT1 in the presence of REPAT8. REPAT1 alone was localized exclusively in the cytoplasm, while the presence of REPAT8 led to the migration of REPAT1 to the nucleus. Finally, analysis of the expression pattern of eight REPAT members has shown that B. thuringiensis-related treatments (Cry1Ca toxin, Xentari™ product and an acrystalliferous strain) induced a general up-regulation of repat genes, especially of repat2. In contrast, no significant effect was detected after treatment with Escherichia coli or Enterococcus sp., or by the presence of microbiota in the midgut. The results suggest that the different repat genes play different roles in response to pathogens.
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Opportunities and challenges for the baculovirus expression system. J Invertebr Pathol 2011; 107 Suppl:S3-15. [PMID: 21784228 DOI: 10.1016/j.jip.2011.05.001] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2011] [Revised: 01/28/2011] [Accepted: 01/28/2011] [Indexed: 11/23/2022]
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Partial functional rescue of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus infectivity by replacement of F protein with GP64 from Autographa californica multicapsid nucleopolyhedrovirus. J Virol 2010; 84:11505-14. [PMID: 20739531 DOI: 10.1128/jvi.00862-10] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Two distinct envelope fusion proteins (EFPs) (GP64 and F) have been identified in members of the Baculoviridae family of viruses. F proteins are found in group II nucleopolyhedroviruses (NPVs) of alphabaculoviruses and in beta- and deltabaculoviruses, while GP64 occurs only in group I NPVs of alphabaculoviruses. It was proposed that an ancestral baculovirus acquired the gp64 gene that conferred a selective advantage and allowed it to evolve into group I NPVs. The F protein is a functional analogue of GP64, as evidenced from the rescue of gp64-null Autographa californica multicapsid nucleopolyhedrovirus (MNPV) (AcMNPV) by F proteins from group II NPVs or from betabaculoviruses. However, GP64 failed to rescue an F-null Spodoptera exigua MNPV (SeMNPV) (group II NPV). Here, we report the successful generation of an infectious gp64-rescued group II NPV of Helicoverpa armigera (vHaBacΔF-gp64). Viral growth curve assays and quantitative real-time PCR (Q-PCR), however, showed substantially decreased infectivity of vHaBacΔF-gp64 compared to the HaF rescue control virus vHaBacΔF-HaF. Electron microscopy further showed that most vHaBacΔF-gp64 budded viruses (BV) in the cell culture supernatant lacked envelope components and contained morphologically aberrant nucleocapsids, suggesting the improper BV envelopment or budding of vHaBacΔF-gp64. Bioassays using pseudotyped viruses with a reintroduced polyhedrin gene showed that GP64-pseudotyped Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV) significantly delayed the mortality of infected H. armigera larvae.
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Westenberg M, Soedling HM, Mann DA, Nicholson LJ, Dolphin CT. Counter-selection recombineering of the baculovirus genome: a strategy for seamless modification of repeat-containing BACs. Nucleic Acids Res 2010; 38:e166. [PMID: 20621982 PMCID: PMC2938205 DOI: 10.1093/nar/gkq596] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Recombineering is employed to modify large DNA clones such as fosmids, BACs and PACs. Subtle and seamless modifications can be achieved using counter-selection strategies in which a donor cassette carrying both positive and negative markers inserted in the target clone is replaced by the desired sequence change. We are applying counter-selection recombineering to modify bacmid bMON14272, a recombinant baculoviral genome, as we wish to engineer the virus into a therapeutically useful gene delivery vector with cell targeting characteristics. Initial attempts to replace gp64 with Fusion (F) genes from other baculoviruses resulted in many rearranged clones in which the counter-selection cassette had been deleted. Bacmid bMON14272 contains nine highly homologous regions (hrs) and deletions were mapped to recombination between hr pairs. Recombineering modifications were attempted to decrease intramolecular recombination and/or increase recombineering efficiency. Of these only the use of longer homology arms on the donor molecule proved effective permitting seamless modification. bMON14272, because of the presence of the hr sequences, can be considered equivalent to a highly repetitive BAC and, as such, the optimized method detailed here should prove useful to others applying counter-selection recombineering to modify BACs or PACs containing similar regions of significant repeating homologies.
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Affiliation(s)
- Marcel Westenberg
- Pharmaceutical Science Division, King's College London, London SE1 9NH, UK
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30
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Genomic sequencing and analyses of Lymantria xylina multiple nucleopolyhedrovirus. BMC Genomics 2010; 11:116. [PMID: 20167051 PMCID: PMC2830988 DOI: 10.1186/1471-2164-11-116] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 02/18/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Outbreaks of the casuarina moth, Lymantria xylina Swinehoe (Lepidoptera: Lymantriidae), which is a very important forest pest in Taiwan, have occurred every five to 10 years. This moth has expanded its range of host plants to include more than 65 species of broadleaf trees. LyxyMNPV (L. xylina multiple nucleopolyhedrovirus) is highly virulent to the casuarina moth and has been investigated as a possible biopesticide for controlling this moth. LdMNPV-like virus has also been isolated from Lymantria xylina larvae but LyxyMNPV was more virulent than LdMNPV-like virus both in NTU-LY and IPLB-LD-652Y cell lines. To better understand LyxyMNPV, the nucleotide sequence of the LyxyMNPV DNA genome was determined and analysed. RESULTS The genome of LyxyMNPV consists of 156,344 bases, has a G+C content of 53.4% and contains 157 putative open reading frames (ORFs). The gene content and gene order of LyxyMNPV were similar to those of LdMNPV, with 151 ORFs identified as homologous to those reported in the LdMNPV genome. Two genes (Lyxy49 and Lyxy123) were homologous to other baculoviruses, and four unique LyxyMNPV ORFs (Lyxy11, Lyxy19, Lyxy130 and Lyxy131) were identified in the LyxyMNPV genome, including a gag-like gene that was not reported in baculoviruses. LdMNPV contains 23 ORFs that are absent in LyxyMNPV. Readily identifiable homologues of the gene host range factor-1 (hrf-1), which appears to be involved in the susceptibility of L. dispar to NPV infection, were not present in LyxyMNPV. Additionally, two putative odv-e27 homologues were identified in LyxyMNPV. The LyxyMNPV genome encoded 14 bro genes compared with 16 in LdMNPV, which occupied more than 8% of the LyxyMNPV genome. Thirteen homologous regions (hrs) were identified containing 48 repeated sequences composed of 30-bp imperfect palindromes. However, they differed in the relative positions, number of repeats and orientation in the genome compared to LdMNPV. CONCLUSION The gene parity plot analysis, percent identity of the gene homologues and a phylogenetic analysis suggested that LyxyMNPV is a Group II NPV that is most closely related to LdMNPV but with a highly distinct genomic organisation.
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Jakubowska A, Ferré J, Herrero S. Enhancing the multiplication of nucleopolyhedrovirus in vitro by manipulation of the pH. J Virol Methods 2009; 161:254-8. [PMID: 19576934 DOI: 10.1016/j.jviromet.2009.06.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/17/2009] [Accepted: 06/23/2009] [Indexed: 11/29/2022]
Abstract
Insect nucleopolyhedroviruses (NPVs) are studied widely as agents for biological control, as expression vectors for the production of heterologous proteins, and as transduction vectors for gene therapy applications. Most of these applications rely on the existence of cell lines that allow in vitro multiplication of the virus. The influence of pH in the medium culture on the multiplication of SeMNPV, HearSNPV and AcMNPV in different cell culture lines was investigated. The study showed a strong influence of the medium pH on the virus multiplication with the best results at pH 6.5, about half pH unit above the pH of insect culture media used most commonly. Additional experiments using a recombinant AcMNPV, expressing the green fluorescent protein, suggested that the enhanced virus multiplication at pH 6.5 is due mainly to a facilitated entry of the budded virions into the cells.
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Affiliation(s)
- Agata Jakubowska
- Department of Genetics, Universitat de València, Burjassot (Valencia), Spain
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33
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Yu IL, Bray D, Lin YC, Lung O. Autographa californica multiple nucleopolyhedrovirus ORF 23 null mutant produces occlusion-derived virions with fewer nucleocapsids. J Gen Virol 2009; 90:1499-1504. [DOI: 10.1099/vir.0.009035-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two envelope fusion protein gene homologues have been identified in the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). AcMNPV GP64 protein is fusogenic and essential for propagation and pathogenicity. The F homologue (Ac23) is not essential, is fusion-incompetent in standard assays, but contributes to faster host death. Here, we show that occlusion bodies (OBs) from Ac23null mutants and control viruses do not differ significantly in size and the number of occlusion-derived virions (ODVs) contained; however, Ac23null OBs had a much higher percentage of ODVs with a single nucleocapsid (44.6 %) than the near-isogenic control (11.3 %). Infection of Sf9 cells with Ac23–green fluorescent protein (gfp)-expressing recombinant viruses showed Ac23–gfp fluorescence overlapping perinuclear DAPI staining at later times, a pattern not observed with GP64. These results suggest that F proteins have evolved functions beyond envelope fusion and play a different role from that of GP64 in viruses that contain both proteins.
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Affiliation(s)
- Ian-Ling Yu
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Doug Bray
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Ying-Chu Lin
- Faculty of Dentistry, Kaohsiung Medical University, Kaohsiung, Taiwan, ROC
| | - Oliver Lung
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
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Hilton S, Winstanley D. Genomic sequence and biological characterization of a nucleopolyhedrovirus isolated from the summer fruit tortrix, Adoxophyes orana. J Gen Virol 2009; 89:2898-2908. [PMID: 18931089 DOI: 10.1099/vir.0.2008/002881-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Adoxophyes orana nucleopolyhedrovirus (AdorNPV) was isolated from overwintering larvae from an orchard in the UK. The nucleotide sequence of the AdorNPV DNA genome was determined and analysed. The genome contains 111724 bp and has a G+C content of 35.0 mol%. The analysis predicted 121 ORFs of 150 nt or larger. Of these putative genes, 118 were homologous to genes identified previously in the Adoxophyes honmai nucleopolyhedrovirus (AdhoNPV) genome (83.3-100 % aa identity), and three AdorNPV ORFs were unique. There were four small homologous regions that consisted of a similar core sequence and at the same relative positions in the genome as AdhoNPV, but they differed in the number of repeats and orientation. Some genes that have been reported to have major roles in baculovirus biology were either absent or truncated in the AdorNPV genome. These included chitinase, which is involved in the liquefaction of the host, and the C-terminal of the ecdysteroid UDP-glucosyltransferase (egt) protein, which was truncated by 149 aa compared with AdhoNPV, with essential amino acids absent. The AdorNPV genome encoded two inhibitor of apoptosis (iap) genes compared with three in AdhoNPV and three bro genes compared with four in AdhoNPV. The susceptibility of A. orana larvae to AdorNPV was evaluated in laboratory bioassays using inoculation by microdroplet feeding and applied dose assays. LD50 for neonates was 56 occlusion bodies rising to 2.3x10(4) for fifth instar larvae. Median survival time values using an LD80 dose were 8.8 days for neonates and 7.0 days for fifth instar larvae.
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Bombyx mori nucleopolyhedrovirus ORF51 encodes a budded virus envelope associated protein. Virus Genes 2008; 38:171-7. [PMID: 19085095 DOI: 10.1007/s11262-008-0312-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2008] [Accepted: 11/26/2008] [Indexed: 10/21/2022]
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) ORF 51 (Bm51) is a gene present in many lepidopteran NPVs, but its function is unknown. In this study, Bm51 was characterized. Transcripts of Bm51 were detected from 4.5 through 72 hour post infection (h p.i.) by RT-PCR. The corresponding protein was detected from 6 to 72 h p.i. in BmNPV-infected BmN cells by western blot analysis using a polyclonal antibody against Bm51. Western blot assay of occlusion-derived virus and budded virus (BV) preparations revealed that Bm51 encodes a 23-kDa structural protein that is associated with BV and is located in the envelope fraction of budded virions. The protein was temporarily called BV-E23. In addition immunofluorescence microscopy demonstrated that the protein was present within the cytoplasm and nuclei in virus-infected cells. In conclusion, the available data suggest that Bm51 is a functional ORF of BmNPV and encodes a protein expressed in the early stage of the infection cycle that is associated with the BV envelope.
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36
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Song J, Wang R, Deng F, Wang H, Hu Z. Functional studies of per os infectivity factors of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus. J Gen Virol 2008; 89:2331-2338. [PMID: 18753243 DOI: 10.1099/vir.0.2008/002352-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A combined functional investigation on the four per os infectivity factors (PIFs) of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV) was conducted in this study. HearNPV bacmids with deletions of p74 (Ha20), pif1 (Ha111), pif2 (Ha132) and pif3 (Ha98) were constructed individually by homologous recombination in Escherichia coli cells. Repaired bacmids with respective pifs were also constructed. Western blot analyses revealed that all four PIFs were structural components of the envelope of HearNPV occlusion-derived virus (ODV). Electron microscopy showed that deletion of the pifs did not have any obvious effects on the morphology of the occlusion bodies (OBs). Bioassay analyses indicated that deletion of any of the above pifs resulted in loss of oral infectivity of OBs. The mixtures of the four pif-deletion mutants also resulted in deficiency of oral infectivity, implying that the four PIFs must be structural components of the same ODV to accomplish their function. Repairing of the respective genes into the pif-deletion bacmids could rescue the oral infectivity of the pif-deletion viruses. Calcofluor, which can damage the peritrophic membrane (PM), could not rescue the defects of the oral infectivity of the pif-deletion viruses, indicating that the PM is not likely to be the functional target of the PIFs.
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Affiliation(s)
- Jingjiao Song
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Ranran Wang
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Fei Deng
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Hualin Wang
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Zhihong Hu
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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The F-like protein Ac23 enhances the infectivity of the budded virus of gp64-null Autographa californica multinucleocapsid nucleopolyhedrovirus pseudotyped with baculovirus envelope fusion protein F. J Virol 2008; 82:9800-4. [PMID: 18653446 DOI: 10.1128/jvi.00759-08] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The GP64 and F proteins were previously identified as the sole functional envelope fusion proteins in Baculoviridae. F-like proteins, present only in group I nucleopolyhedroviruses (NPVs), are remnant, nonfunctional F proteins. In this report, we describe the effect of the presence or absence of the F-like protein Ac23 in a gp64-null Autographa californica multinucleocapsid NPV pseudotyped with the F protein from Spodoptera exigua multicapsid NPV (SeF). We found that the presence of Ac23 elevates the infectivity of the pseudotyped virus. This is in contrast to the results of Lung et al. (J. Virol. 76:5729-5736, 2002), who found no such effect. The possible reasons for the differing results are discussed.
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A functional F analogue of Autographa californica nucleopolyhedrovirus GP64 from the Agrotis segetum granulovirus. J Virol 2008; 82:8922-6. [PMID: 18562524 DOI: 10.1128/jvi.00493-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The envelope fusion protein F of Plutella xylostella granulovirus is a computational analogue of the GP64 envelope fusion protein of Autographa californica nucleopolyhedrovirus (AcMNPV). Granulovirus (GV) F proteins were thought to be unable to functionally replace GP64 in the AcMNPV pseudotyping system. In the present study the F protein of Agrotis segetum GV (AgseGV) was identified experimentally as the first functional GP64 analogue from GVs. AgseF can rescue virion propagation and infectivity of gp64-null AcMNPV. The AgseF-pseudotyped AcMNPV also induced syncytium formation as a consequence of low-pH-induced membrane fusion.
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39
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Mutagenesis and nuclear magnetic resonance analyses of the fusion peptide of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus F protein. J Virol 2008; 82:8138-48. [PMID: 18524820 DOI: 10.1128/jvi.00368-08] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The entry of enveloped viruses into cells is normally mediated by fusion between viral and cellular membranes, in which the fusion peptide plays a crucial role. The fusion peptides of group II nucleopolyhedrovirus (NPV) F proteins are quite conserved, with a hydrophobic region located at the N terminal of the F(1) fragment. For this report, we used mutagenesis and nuclear magnetic resonance (NMR) to study the structure and function of the fusion peptide of the Helicoverpa armigera single-nucleocapsid NPV (HearNPV) F protein (HaF). Five mutations in the fusion peptide of HaF, N(1)G, N(1)L, I(2)N, G(3)L, and D(11)L, were generated separately, and the mutated f genes were transformed into the f-null HearNPV bacmid. The mutations N(1)L, I(2)N, and D(11)L were found to completely abolish the ability of the recombinant bacmids to produce infectious budded virus, while the mutations N(1)G and G(3)L did not. The low-pH-induced envelope fusion assay demonstrated that the N(1)G substitution increased the fusogenicity of HaF, while the G(3)L substitution reduced its fusogenicity. NMR spectroscopy was used to determine the structure of a synthetic fusion peptide of HaF in the presence of sodium dodecyl sulfate micelles at pH 5.0. The fusion peptide appeared to be an amphiphilic structure composed of a flexible coil in the N terminus from N(1) to N(5), a 3(10)-helix from F(6) to G(8), a turn at S(9), and a regular alpha-helix from V(10) to D(19). The data provide the first NMR structure of a baculovirus fusion peptide and allow us to further understand the relationship of structure and function of the fusion peptide.
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Wang M, Tan Y, Yin F, Deng F, Vlak JM, Hu Z, Wang H. The F protein of Helicoverpa armigera single nucleopolyhedrovirus can be substituted functionally with its homologue from Spodoptera exigua multiple nucleopolyhedrovirus. J Gen Virol 2008; 89:791-798. [PMID: 18272771 DOI: 10.1099/vir.0.83466-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
F proteins of group II nucleopolyhedroviruses (NPVs) are envelope fusion proteins essential for virus entry and egress. An F-null Helicoverpa armigera single nucleocapsid NPV (HearNPV) bacmid, HaBacDeltaF, was constructed. This bacmid could not produce infectious budded virus (BV) when transfected into HzAM1 cells, showing that F protein is essential for cell-to-cell transmission of BVs. When HaBacDeltaF was pseudotyped with the homologous F protein (HaBacDeltaF-HaF, positive control) or with the heterologous F protein from Spodoptera exigua multinucleocapsid NPV (SeMNPV) (HaBacDeltaF-SeF), infectious BVs were produced with similar kinetics. In the late phase of infection, the BV titre of HaBacDeltaF-SeF virus was about ten times lower than that of HaBacDeltaF-HaF virus. Both pseudotyped viruses were able to fuse HzAM1 cells in a similar fashion. The F proteins of both HearNPV and SeMNPV were completely cleaved into F(1) and F(2) in the BVs of vHaBacDeltaF-HaF and vHaBacDeltaF-SeF, respectively, but the cleavage of SeF in vHaBacDeltaF-SeF-infected HzAM1 cells was incomplete, explaining the lower BV titre of vHaBacDeltaF-SeF. Polyclonal antisera against HaF(1) and SeF(1) specifically neutralized the infection of vHaBacDeltaF-HaF and vHaBacDeltaF-SeF, respectively. HaF(1) antiserum showed some cross-neutralization with vHaBacDeltaF-SeF. These results demonstrate that group II NPV F proteins can be functionally replaced with a homologue of other group II NPVs, suggesting that the interaction of F with other viral or host proteins is not absolutely species-specific.
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Affiliation(s)
- Manli Wang
- Graduate School of the Chinese Academy of Sciences, Beijing 100039, PR China.,State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Ying Tan
- Graduate School of the Chinese Academy of Sciences, Beijing 100039, PR China.,State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Feifei Yin
- Graduate School of the Chinese Academy of Sciences, Beijing 100039, PR China.,State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Fei Deng
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, 6709 PD Wageningen, The Netherlands
| | - Zhihong Hu
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Hualin Wang
- State Key Laboratory of Virology and Joint Laboratory of Invertebrate Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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Westenberg M, Vlak JM. GP64 of group I nucleopolyhedroviruses cannot readily rescue infectivity of group II f-null nucleopolyhedroviruses. J Gen Virol 2008; 89:424-431. [PMID: 18198373 DOI: 10.1099/vir.0.83342-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The genus Nucleopolyhedrovirus (NPV) of the family Baculoviridae can be subdivided phylogenetically into two groups. The same division can be made on the basis of their budded virus (BV) envelope fusion protein. Group I NPVs are characterized by the presence of a GP64-like major envelope fusion protein, which is involved in viral attachment and the fusion of virus and cell membrane, and is required for budding of progeny nucleocapsids. Group II NPVs have an envelope fusion protein unrelated to GP64, named F. In contrast to GP64, F proteins are found in all baculoviruses, but they are not functional as envelope fusion proteins in group I NPVs. Autographa californica multiple NPV (AcMNPV) lacking GP64 can be pseudotyped by the F protein of Spodoptera exigua multiple NPV (SeMNPV), suggesting that F proteins are functionally analogous to GP64. GP64 homologues are thought to have been acquired by group I NPVs during evolution, thereby giving these viruses a selective advantage and obviating the need for a functional F protein. To address this supposition experimentally, attempts were made to pseudotype a group II NPV, SeMNPV, with GP64. Transfection of an f-null SeMNPV bacmid into Se301 cells did not result in the production of infectious BVs. This defect was rescued by insertion of SeMNPV f, but not by insertion of AcMNPV gp64. This suggests that the functional analogy between GP64 and F is not readily reciprocal and that F proteins from group II NPVs may provide additional functions in BV formation that are lacking in the GP64 type of fusion protein.
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Affiliation(s)
- Marcel Westenberg
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
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Identification of a GP64 subdomain involved in receptor binding by budded virions of the baculovirus Autographica californica multicapsid nucleopolyhedrovirus. J Virol 2008; 82:4449-60. [PMID: 18287233 DOI: 10.1128/jvi.02490-07] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enveloped virus entry into host cells is typically initiated by an interaction between a viral envelope glycoprotein and a host cell receptor. For budded virions of the baculovirus Autographa californica multicapsid nucleopolyhedrovirus, the envelope glycoprotein GP64 is involved in host cell receptor binding, and GP64 is sufficient to mediate low-pH-triggered membrane fusion. To better define the role of GP64 in receptor binding, we generated and characterized a panel of antisera against subdomains of GP64. Eight subdomain-specific antisera were generated, and their reactivities with GP64 proteins and neutralization of virus infectivity and binding were examined. Antibodies directed against the N-terminal region of GP64 (amino acids 21 to 159) showed strong neutralization of infectivity and effectively inhibited binding of (35)S-labeled budded virions to Sf9 cells. In addition, we generated virions displaying truncated GP64 constructs. A construct displaying the N-terminal 274 amino acids (residues 21 to 294) of the ectodomain was sufficient to mediate virion binding. Additional studies of antisera directed against small subdomains revealed that an antiserum against a 40-amino-acid region (residues 121 to 160) neutralized virus infectivity. Site-directed mutagenesis was subsequently used for functional analysis of that region. Recombinant viruses expressing GP64 proteins with single amino acid substitutions within amino acids 120 to 124 and 142 to 148 replicated to high titers, suggesting that those amino acids were not critical for receptor binding or other important GP64 functions. In contrast, GP64 proteins with single amino acid substitutions of residues 153 and 156 were unable to substitute for wild-type GP64 and did not rescue a gp64 knockout virus. Further analysis showed that these substitutions substantially reduced binding of recombinant virus to Sf9 cells. Thus, the amino acid region from positions 21 to 159 was identified as a putative receptor binding domain, and amino acids 153 and 156 appear to be important for receptor binding.
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Westenberg M, Uijtdewilligen P, Vlak JM. Baculovirus envelope fusion proteins F and GP64 exploit distinct receptors to gain entry into cultured insect cells. J Gen Virol 2008; 88:3302-3306. [PMID: 18024899 DOI: 10.1099/vir.0.83240-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Group II nucleopolyhedroviruses (NPVs), e.g. Helicoverpa armigera (Hear) NPV and Spodoptera exigua (Se) MNPV (multiple NPV), lack a GP64-like protein that is present in group I NPVs, e.g. Autographa californica (Ac)MNPV, but have an unrelated envelope fusion protein named F. Three AcMNPV viruses were constructed by introducing AcMNPV gp64, HearNPV f or SeMNPV f genes, respectively, into a gp64-negative AcMNPV bacmid. Sf21 cells were incubated with different amounts of inactivated budded virus to occupy receptors and were subsequently infected with a fixed amount of infectious virus to compete for attachment. The results suggest that GP64 and F act on their own and use different receptors, while the two different F proteins exploit the same receptor. Additionally, gp64-null AcMNPV pseudotyped with baculovirus F was, in contrast to GP64, unable to transduce mammalian cells, indicating that mammalian cells do not possess baculovirus F protein receptors despite the structural similarity of baculovirus F to vertebrate viral fusion proteins.
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Affiliation(s)
- Marcel Westenberg
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - Peter Uijtdewilligen
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
| | - Just M Vlak
- Laboratory of Virology, Wageningen University, Binnenhaven 11, 6709 PD Wageningen, The Netherlands
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Conserved leucines in N-terminal heptad repeat HR1 of envelope fusion protein F of group II nucleopolyhedroviruses are important for correct processing and essential for fusogenicity. J Virol 2007; 82:2437-47. [PMID: 18094156 DOI: 10.1128/jvi.01885-07] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
The heptad repeat (HR), a conserved structural motif of class I viral fusion proteins, is responsible for the formation of a six-helix bundle structure during the envelope fusion process. The insect baculovirus F protein is a newly found budded virus envelope fusion protein which possesses common features to class I fusion proteins, such as proteolytic cleavage and the presence of an N-terminal open fusion peptide and multiple HR domains on the transmembrane subunit F(1). Similar to many vertebrate viral fusion proteins, a conserved leucine zipper motif is predicted in this HR region proximal to the fusion peptide in baculovirus F proteins. To facilitate our understanding of the functional role of this leucine zipper-like HR1 domain in baculovirus F protein synthesis, processing, and viral infectivity, key leucine residues (Leu209, Leu216, and Leu223) were replaced by alanine (A) or arginine (R), respectively. By using Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) as a pseudotype expression system, we demonstrated that all mutant F proteins incorporated into budded virus, indicating that leucine substitutions did not affect intercellular trafficking of F. Furin-like protease cleavage was not affected by any of the leucine substitutions; however, the disulfide bridging and N-linked glycosylation patterns were partly altered. Single substitutions in HR1 showed that the three leucine residues were critical for F fusogenicity and the rescue of AcMNPV infectivity. Our results support the view that the leucine zipper-like HR1 domain is important to safeguard the proper folding, glycosylation, and fusogenicity of baculovirus F proteins.
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Display of heterologous proteins on gp64null baculovirus virions and enhanced budding mediated by a vesicular stomatitis virus G-stem construct. J Virol 2007; 82:1368-77. [PMID: 17989172 DOI: 10.1128/jvi.02007-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) GP64 envelope glycoprotein is essential for virus entry and plays an important role in virion budding. An AcMNPV construct that contains a deletion of the gp64 gene is unable to propagate infection from cell to cell, and this defect results from both a severe reduction in the production of budded virions and the absence of GP64 on virions. In the current study, we examined GP64 proteins containing N- and C-terminal truncations of the ectodomain and identified a minimal construct capable of targeting the truncated GP64 to budded virions. The minimal budding and targeting construct of GP64 contained 38 amino acids from the mature N terminus of the GP64 ectodomain and 52 amino acids from the C terminus of GP64. Because the vesicular stomatitis virus (VSV) G protein was previously found to rescue infectivity of a gp64null AcMNPV, we also examined a small C-terminal construct of the VSV G protein. We found that a construct containing 91 amino acids from the C terminus of VSV G (termed G-stem) was capable of rescuing AcMNPV gp64null virion budding to wild-type (wt) or nearly wt levels. We also examined the display of chimeric proteins on the gp64null AcMNPV virion. By generating viruses that expressed chimeric influenza virus hemagglutinin (HA) proteins containing the GP64 targeting domain and coinfecting those viruses with a virus expressing the G-stem construct, we demonstrated enhanced display of the HA protein on gp64null AcMNPV budded virions. The combined use of gp64null virions, VSV G-stem-enhanced budding, and GP64 domains for targeting heterologous proteins to virions should be valuable for biotechnological applications ranging from targeted transduction of mammalian cells to vaccine production.
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Free-living pathogens: life-history constraints and strain competition. J Theor Biol 2007; 250:569-79. [PMID: 18062992 DOI: 10.1016/j.jtbi.2007.10.029] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 10/24/2007] [Accepted: 10/25/2007] [Indexed: 11/23/2022]
Abstract
Many pathogen life histories include a free-living stage, often with anatomical and physiological adaptations promoting persistence outside of host tissues. More durable particles presumably require that the pathogen metabolize more resources per particle. Therefore, we hypothesize functional dependencies, pleiotropic constraints, between the rate at which free-living particles decay outside of host tissues and other pathogen traits, including virulence, the probability of infecting a host upon contact, and pathogen reproduction within host tissues. Assuming that pathogen strains compete for hosts preemptively, we find patterns in trait dependencies predicting whether or not strain competition favors a highly persistent free-living stage.
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Chitnis NS, D'Costa SM, Paul ER, Bilimoria SL. Modulation of iridovirus-induced apoptosis by endocytosis, early expression, JNK, and apical caspase. Virology 2007; 370:333-42. [PMID: 17942133 PMCID: PMC7103334 DOI: 10.1016/j.virol.2007.09.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2007] [Revised: 09/04/2007] [Accepted: 09/10/2007] [Indexed: 01/17/2023]
Abstract
Chilo iridescent virus (CIV) is the type species for the family Iridoviridae, which are large, isometric, cytoplasmic dsDNA viruses. We examined the mechanism of apoptosis induction by CIV. High CIV doses (CIVXS; 400 μg/ml), UV-irradiated virus (CIVUV; 10 μg/ml) and CVPE (CIV protein extract; 10 μg/ml) induced apoptosis in 60% of treated Choristoneura fumiferana (IPRI-CF-124T) cells. Normal doses of infectious CIV (10 μg/ml) induced apoptosis in only 10% of C. fumiferana (CF) cells. Apoptosis was inhibited by Z-IETD-FMK, an apical caspase inhibitor, indicating that CIV-induced apoptosis requires caspase activity. The putative caspase in CF cells was designated Cf-caspase-i. CIVUV or CVPE enhanced Cf-caspase-i activity by 80% at 24 h relative to mock-treated cells. Since the MAP kinase pathway induces or inhibits apoptosis depending on the context, we used JNK inhibitor SP600125 and demonstrated drastic suppression of CVPE-induced apoptosis. Thus, the JNK signaling pathway is significant for apoptosis in this system. Virus interaction with the cell surface was not sufficient for apoptosis since CIVUV particles bound to polysterene beads failed to induce apoptosis. Endocytosis inhibitors (bafilomycin or ammonium chloride) negated apoptosis induction by CIVUV, CIVXS or CVPE indicating that entry through this mode is required. Given the weak apoptotic response to infectious CIV, we postulated that viral gene expression inhibited apoptosis. CIV infection of cells pretreated with cycloheximide induced apoptosis in 69% of the cells compared to 10% in normal infections. Furthermore, blocking viral DNA replication with aphidicolin or phosphonoacetic acid suppressed apoptosis and Cf-caspase-i activity, indicating that early viral expression is necessary for inhibition of apoptosis, and de novo synthesis of viral proteins is not required for induction. We show for the first time that, in a member of the family Iridoviridae, apoptosis: (i) requires entry and endocytosis of virions or virion proteins, (ii) is inhibited under conditions permitting early viral expression, and (iii) requires the JNK signaling pathway. This is the first report of JNK signal requirement during apoptosis induction by an insect virus.
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Affiliation(s)
- Nilesh S Chitnis
- Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409-3131, USA
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Deng F, Wang R, Fang M, Jiang Y, Xu X, Wang H, Chen X, Arif BM, Guo L, Wang H, Hu Z. Proteomics analysis of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus identified two new occlusion-derived virus-associated proteins, HA44 and HA100. J Virol 2007; 81:9377-85. [PMID: 17581982 PMCID: PMC1951453 DOI: 10.1128/jvi.00632-07] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2007] [Accepted: 06/14/2007] [Indexed: 11/20/2022] Open
Abstract
Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry were used to analyze the structural proteins of the occlusion-derived virus (ODV) of Helicoverpa armigera single nucleocapsid nucleopolyhedrovirus (HearNPV), a group II NPV. Twenty-three structural proteins of HearNPV ODV were identified, 21 of which have been reported previously as structural proteins or ODV-associated proteins in other baculoviruses. These include polyhedrin, P78/83, P49, ODV-E18, ODV-EC27, ODV-E56, P74, LEF-3, HA66 (AC66), DNA polymerase, GP41, VP39, P33, ODV-E25, helicase, P6.9, ODV/BV-C42, VP80, ODV-EC43, ODV-E66, and PIF-1. Two proteins encoded by HearNPV ORF44 (ha44) and ORF100 (ha100) were discovered as ODV-associated proteins for the first time. ha44 encodes a protein of 378 aa with a predicted mass of 42.8 kDa. ha100 encodes a protein of 510 aa with a predicted mass of 58.1 kDa and is a homologue of the gene for poly(ADP-ribose) glycohydrolase (parg). Western blot analysis and immunoelectron microscopy confirmed that HA44 is associated with the nucleocapsid and HA100 is associated with both the nucleocapsid and the envelope of HearNPV ODV. HA44 is conserved in group II NPVs and granuloviruses but does not exist in group I NPVs, while HA100 is conserved only in group II NPVs.
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Affiliation(s)
- Fei Deng
- State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, People's Republic of China
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