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Bai L, Sun Y, Yue X, Ji N, Yan F, Yang T, Feng G, Guo Y, Li Z. Multifaceted interactions between host ESCRT-III and budded virus-related proteins involved in entry and egress of the baculovirus Autographa californica multiple nucleopolyhedrovirus. J Virol 2024; 98:e0190023. [PMID: 38289107 PMCID: PMC10878073 DOI: 10.1128/jvi.01900-23] [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: 12/04/2023] [Accepted: 12/19/2023] [Indexed: 02/21/2024] Open
Abstract
The endosomal sorting complex required for transport (ESCRT) is a conserved protein machine mediating membrane remodeling and scission. In the context of viral infection, different components of the ESCRT-III complex, which serve as the core machinery to catalyze membrane fission, are involved in diverse viruses' entry, replication, and/or budding. However, the interplay between ESCRT-III and viral factors in the virus life cycle, especially for that of large enveloped DNA viruses, is largely unknown. Recently, the ESCRT-III components Vps2B, Vps20, Vps24, Snf7, Vps46, and Vps60 were determined for entry and/or egress of the baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV). Here, we identified the final three ESCRT-III components Chm7, Ist1, and Vps2A of Spodoptera frugiperda. Overexpression of the dominant-negative forms of these proteins or RNAi downregulation of their transcripts significantly reduced infectious budded viruses (BVs) production of AcMNPV. Quantitative PCR together with confocal and transmission electron microscopy analysis revealed that these proteins were required for internalization and trafficking of BV during entry and egress of nucleocapsids. In infected Sf9 cells, nine ESCRT-III components were distributed on the nuclear envelope and plasma membrane, and except for Chm7, the other components were also localized to the intranuclear ring zone. Y2H and BiFC analysis revealed that 42 out of 64 BV-related proteins including 35 BV structural proteins and 7 non-BV structural proteins interacted with single or multiple ESCRT-III components. By further mapping the interactome of 64 BV-related proteins, we established the interaction networks of ESCRT-III and the viral protein complexes involved in BV entry and egress.IMPORTANCEFrom archaea to eukaryotes, the endosomal sorting complex required for transport (ESCRT)-III complex is hijacked by many enveloped and nonenveloped DNA or RNA viruses for efficient replication. However, the mechanism of ESCRT-III recruitment, especially for that of large enveloped DNA viruses, remains elusive. Recently, we found the ESCRT-III components Vps2B, Vps20, Vps24, Snf7, Vps46, and Vps60 are necessary for the entry and/or egress of budded viruses (BVs) of Autographa californica multiple nucleopolyhedrovirus. Here, we demonstrated that the other three ESCRT-III components Chm7, Ist1, and Vps2A play similar roles in BV infection. By determining the subcellular localization of ESCRT-III components in infected cells and mapping the interaction of nine ESCRT-III components and 64 BV-related proteins, we built the interaction networks of ESCRT-III and the viral protein complexes involved in BV entry and egress. These studies provide a fundamental basis for understanding the mechanism of the ESCRT-mediated membrane remodeling for replication of baculoviruses.
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Affiliation(s)
- Lisha Bai
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Yu Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaorong Yue
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Ning Ji
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Fanye Yan
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Tian Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Guozhong Feng
- State Key Laboratory of Rice Biology and Breeding, China National Rice Research Institute, Chinese Academy of Agricultural Sciences, Hangzhou, China
| | - Ya Guo
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhaofei Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, Key Laboratory of Plant Protection Resources and Pest Management of Ministry of Education, Key Laboratory of Integrated Pest Management on the Loess Plateau of Ministry of Agriculture and Rural Affairs, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
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2
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Lorenzi A, Arvin MJ, Burke GR, Strand MR. Functional characterization of Microplitis demolitor bracovirus genes that encode nucleocapsid components. J Virol 2023; 97:e0081723. [PMID: 37877717 PMCID: PMC10688341 DOI: 10.1128/jvi.00817-23] [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: 05/30/2023] [Accepted: 09/19/2023] [Indexed: 10/26/2023] Open
Abstract
IMPORTANCE Understanding how bracoviruses (BVs) function in wasps is of broad interest in the study of virus evolution. This study characterizes most of the Microplitis demolitor bracovirus (MdBV) genes whose products are nucleocapsid components. Results indicate several genes unknown outside of nudiviruses and BVs are essential for normal capsid assembly. Results also indicate most MdBV tyrosine recombinase family members and the DNA binding protein p6.9-1 are required for DNA processing and packaging into nucleocapsids.
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Affiliation(s)
- Ange Lorenzi
- Department of Entomology, University of Georgia, Athens, Georgia, USA
| | - Michael J. Arvin
- Department of Entomology, University of Georgia, Athens, Georgia, USA
| | - Gaelen R. Burke
- Department of Entomology, University of Georgia, Athens, Georgia, USA
| | - Michael R. Strand
- Department of Entomology, University of Georgia, Athens, Georgia, USA
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3
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Wang J, Yang J, Lei C, Sun X, Hu J. Phosphorylation of the Autographa californica multiple nucleopolyhedrovirus polyhedron envelope protein plays an important role in the formation of the occlusion body envelope. J Gen Virol 2022; 103. [PMID: 35737520 DOI: 10.1099/jgv.0.001759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During the life cycle of a baculovirus, a crystallized protein matrix, formed by polyhedrin (POLH), is produced. The protein matrix is surrounded by a multilayered protein/carbohydrate envelope, and matrix and envelope together form a mature occlusion body (OB). The polyhedron envelope plays an important role in resistance against adverse external environments. The polyhedron envelope protein (PEP) is the main protein that forms the polyhedron envelope, but the mechanism of formation of the polyhedron envelope is unclear. Here, through immunofluorescence localization observations, we found that PEP interacted with both POLH and P10 during formation of the polyhedron envelope in the late stages of infection, and PEP was also required for P10 incorporation on the surface of OBs. In this process, the phosphorylation of PEP played an important role. PEP was determined to be a phosphorylated protein using the Phos-tag technique, and PK1 was determined to be the phosphokinase of PEP by co-immunoprecipitation and in vitro phosphorylation. Immunofluorescence localization revealed that PEP was continuously phosphorylated by PK1 after PEP entered the nucleus until PEP was correctly packaged on the OB surface. Multi-point mutations of PEP conservative potential phosphorylation sites showed that the simultaneous mutation of S85, T86 and Y92 caused changes in the location of PEP and P10 in the late stages of infection, and resulted in an OB surface that lacked the polyhedron envelope. These data suggested that the phosphorylation of PEP at particular sites, i.e. S85, T86 and Y92, plays an important role in the formation of the polyhedron envelope.
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Affiliation(s)
- Jia Wang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.,University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Jian Yang
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China.,University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Chengfeng Lei
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Xiulian Sun
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
| | - Jia Hu
- Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, PR China
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4
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Comprehensive identification of protein orthologs in the family Ascoviridae facilitates an understanding of phylogenomics, protein conservation, and phosphorylation. Arch Virol 2022; 167:1075-1087. [PMID: 35246734 DOI: 10.1007/s00705-022-05402-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 01/18/2022] [Indexed: 11/02/2022]
Abstract
Analysis of orthology is important for understanding protein conservation, function, and phylogenomics. In this study, we performed a comprehensive analysis of gene orthology in the family Ascoviridae based on identification of 366 protein homologue groups and phylogenetic analysis of 34 non-single-copy proteins. Our findings revealed 90 newly annotated proteins, five newly identified core proteins for the family Ascoviridae, and 14 core proteins for the genus Ascovirus. A phylogenomic tree of 11 Ascoviridae members was constructed based on a concatenation of 35 of the 45 ortholog groups. In combination with phosphoproteomic results and conservation estimations, 30 conserved phosphorylation sites on 17 phosphoproteins were identified from a total of 176 phosphosites on 57 phosphoproteins from Heliothis virescens ascovirus 3h (HvAV-3h), providing potential research targets for investigating the role of these protein in the regulation of viral infection. This study will facilitate genome annotation and comparison of further Ascoviridae members as well as functional genomic investigations.
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5
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Wang Y, He J, Mo M, Cai Q, Wu W, Yuan M, Yang K. The amino acids of Autographa californica multiple nucleopolyhedrovirus P48 critical for the association with Ac93 are important for the nuclear egress of nucleocapsids and efficient formation of intranuclear microvesicles. Virus Res 2022; 308:198644. [PMID: 34813875 DOI: 10.1016/j.virusres.2021.198644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/13/2021] [Accepted: 11/18/2021] [Indexed: 11/24/2022]
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) undergoes a biphasic life cycle with the production of two physically and functionally distinct virions: budded virions (BVs) and occlusion-derived virions (ODVs). Nuclear egress of nucleocapsids and intranuclear microvesicle formation are critical for the morphogenesis of BVs and ODVs, respectively, but the mechanisms and details of these two processes remain unknown. Our previous studies have shown that AcMNPV p48 (ac103) gene is essential for the nuclear egress of nucleocapsids and efficient formation of intranuclear microvesicles, and protein P48 associates with Ac93, which is also involved in the above processes in virion morphogenesis. In this study, we present evidence that alanine substitution for residues N318, V319, C320, R321, and I323 of P48 disrupted the association with Ac93. Moreover, mutation of these residues blocked the nuclear egress of nucleocapsids and efficient formation of intranuclear microvesicles, and subsequent BV formation, as well as ODV envelopment and embedding of ODVs into polyhedra. These results suggested that the association between P48 and Ac93 may be important for both BV and ODV morphogenesis.
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Affiliation(s)
- Yan Wang
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Junjie He
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Mei Mo
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Qingyun Cai
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Wenbi Wu
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
| | - Meijin Yuan
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
| | - Kai Yang
- State Key Laboratory of Biocontrol and School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China
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6
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Chen G, Zhao S, Chen N, Wu X. Molecular mechanism responsible for the hyperexpression of baculovirus polyhedrin. Gene 2021; 814:146129. [PMID: 34971751 DOI: 10.1016/j.gene.2021.146129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 12/06/2021] [Accepted: 12/15/2021] [Indexed: 11/25/2022]
Abstract
One of the amazing phenomena in the baculovirus life cycle is the hyperexpression of the very late gene, polyhedrin (polh), causing the production of the occlusion bodies where progeny virions are embedded. However, to date, the molecular mechanism underlying its hyperexpression is not completely elucidated. Considering that, in this review, the mechanism responsible for its hyperexpression from the previous studies up to now was comprehensively summarized from three aspects, namely, the structure characteristics of the polh promoter and transcription regulation, the structure and translation regulation of the polh mRNA, and especially the regulators that influence the expression of polh gene. Moreover, this review will help us obtain a better understanding about the hyperexpression of polh, and also provide guidance for improving the expression efficiency of the foreign proteins by adopting the baculovirus expression vector system.
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Affiliation(s)
- Guanping Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China
| | - Shudi Zhao
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China
| | - Nan Chen
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China
| | - Xiaofeng Wu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China; Key Laboratory of Silkworm and Bee Resource Utilization and Innovation of Zhejiang Province, Hangzhou 310058, China.
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7
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Tang Z, Luo W, Huang Z, Yuan M, Wu W, Yang K. Spodoptera frugiperda mRNA export factor interacts with and mediates the nuclear import of Autographa californica multiple nucleopolyhedrovirus ORF34 (Ac34). Virus Res 2021; 299:198438. [PMID: 33901592 DOI: 10.1016/j.virusres.2021.198438] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/16/2021] [Accepted: 04/20/2021] [Indexed: 01/01/2023]
Abstract
Autographa californica multiple nucleopolyhedrovirus orf34 (ac34) is one of the unique genes of alphabaculoviruses. For successful alphabaculovirus replication, viral proteins must be transported to the nucleus. Our previous study showed that the nuclear localization of Ac34 was required for optimal production of budded virions. To investigate the mechanism of Ac34 nuclear import, mass spectrometric analysis was performed to identify potential proteins that may be involved in the nuclear import of Ac34. The result indicated that Spodoptera frugiperda mRNA export factor (SfMEF) may interact with Ac34 during baculovirus infection. Co-immunoprecipitation assays confirmed that Ac34 could interact with SfMEF in the absence of other baculovirus proteins. The deletion of ac34 did not affect the subcellular localization of SfMEF; however, knocking down Sfmef prevented the nuclear import of Ac34 in virus-infected cells. The mutations of C116 or C119 in a potential CCCH zinc finger motif (C116-X2-C119-X8-C128-X2-H131) of Ac34 led to an exclusive cytoplasmic distribution of Ac34, in consistent with our previous finding of mutations of C128 or H131 in this motif. Co-immunoprecipitation analysis showed that the above mutations in the potential zinc finger motif disrupted the interaction between Ac34 and SfMEF, and the loss of the interaction resulted in decreased BV production. Our findings demonstrated that SfMEF interacts with and mediates the nuclear import of Ac34, which is a new nucleocytoplasmic transport pathway used by alphabaculovirus to achieve successful viral replication within the nucleus of the infected cells.
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Affiliation(s)
- Zhimin Tang
- State Key Lab of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Wangtai Luo
- State Key Lab of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Zhihong Huang
- State Key Lab of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Meijin Yuan
- State Key Lab of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Wenbi Wu
- State Key Lab of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
| | - Kai Yang
- State Key Lab of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
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8
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Oliver MR, Horne CR, Shrestha S, Keown JR, Liang LY, Young SN, Sandow JJ, Webb AI, Goldstone DC, Lucet IS, Kannan N, Metcalf P, Murphy JM. Granulovirus PK-1 kinase activity relies on a side-to-side dimerization mode centered on the regulatory αC helix. Nat Commun 2021; 12:1002. [PMID: 33579933 PMCID: PMC7881018 DOI: 10.1038/s41467-021-21191-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/19/2021] [Indexed: 12/19/2022] Open
Abstract
The life cycle of Baculoviridae family insect viruses depends on the viral protein kinase, PK-1, to phosphorylate the regulatory protein, p6.9, to induce baculoviral genome release. Here, we report the crystal structure of Cydia pomenella granulovirus PK-1, which, owing to its likely ancestral origin among host cell AGC kinases, exhibits a eukaryotic protein kinase fold. PK-1 occurs as a rigid dimer, where an antiparallel arrangement of the αC helices at the dimer core stabilizes PK-1 in a closed, active conformation. Dimerization is facilitated by C-lobe:C-lobe and N-lobe:N-lobe interactions between protomers, including the domain-swapping of an N-terminal helix that crowns a contiguous β-sheet formed by the two N-lobes. PK-1 retains a dimeric conformation in solution, which is crucial for catalytic activity. Our studies raise the prospect that parallel, side-to-side dimeric arrangements that lock kinase domains in a catalytically-active conformation could function more broadly as a regulatory mechanism among eukaryotic protein kinases. The viral Protein Kinase-1 (PK-1) phosphorylates the regulatory protein p6.9, which facilitates baculoviral genome release. Here, the authors combine X-ray crystallography with biophysical and biochemical analyses as well as molecular dynamics simulations to characterize Cydia pomenella granulovirus PK-1, which forms a dimer with a parallel side-to-side arrangement of the kinase domains and furthermore, they provide insights into its catalytic mechanism and evolutionary relationships with other kinases.
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Affiliation(s)
- Michael R Oliver
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Christopher R Horne
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Safal Shrestha
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA
| | - Jeremy R Keown
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Lung-Yu Liang
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Samuel N Young
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia
| | - Jarrod J Sandow
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Andrew I Webb
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - David C Goldstone
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Isabelle S Lucet
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia.,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia
| | - Natarajan Kannan
- Institute of Bioinformatics, University of Georgia, Athens, GA, USA.,Department of Biochemistry and Molecular Biology, University of Georgia, Athens, GA, USA
| | - Peter Metcalf
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.
| | - James M Murphy
- Walter and Eliza Hall Institute of Medical Research, Parkville, VIC, Australia. .,Department of Medical Biology, University of Melbourne, Parkville, VIC, Australia.
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9
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AcMNPV PKIP is required for hyperexpression of very late genes and involved in the hyperphosphorylation of the viral basic protein P6.9. Virus Res 2020; 279:197889. [DOI: 10.1016/j.virusres.2020.197889] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/30/2020] [Accepted: 02/03/2020] [Indexed: 10/25/2022]
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10
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Zhang Y, Wu W, Gao L, Chen M, Liu X, Huang M, Li A, Zheng K, Liu D, Deng H, Zhao B, Liu B, Pang Q. Protein arginine methyltransferase 1 mediates regeneration in Dugesia japonica. Biochem Biophys Res Commun 2020; 524:411-417. [DOI: 10.1016/j.bbrc.2020.01.087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 01/14/2020] [Indexed: 11/30/2022]
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11
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Chen N, Kong X, Zhao S, Xiaofeng W. Post-translational modification of baculovirus-encoded proteins. Virus Res 2020; 279:197865. [DOI: 10.1016/j.virusres.2020.197865] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 01/10/2020] [Accepted: 01/12/2020] [Indexed: 02/03/2023]
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12
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Identification and Characterization of the Nucleolar Localization Signal of Autographa californica Multiple Nucleopolyhedrovirus LEF5. J Virol 2020; 94:JVI.01891-19. [PMID: 31776271 DOI: 10.1128/jvi.01891-19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Accepted: 11/19/2019] [Indexed: 11/20/2022] Open
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) late expression factor 5 (LEF5) is highly conserved in all sequenced baculovirus genomes and plays an important role in production of infectious viral progeny. In this study, nucleolar localization of AcMNPV LEF5 was characterized. Through transcriptome analysis, we identified two putative nucleolar proteins, Spodoptera frugiperda nucleostemin (SfNS) and fibrillarin (SfFBL), from Sf9 cells. Immunofluorescence analysis demonstrated that SfNS and SfFBL were localized to the nucleolus. AcMNPV infection resulted in reorganization of the nucleoli of infected cells. Colocalization of LEF5 and SfNS showed that AcMNPV LEF5 was localized to the nucleolus in Sf9 cells. Bioinformatic analysis revealed that basic amino acids of LEF5 are enriched at residues 184 to 213 and may contain a nucleolar localization signal (NoLS). Green fluorescent protein (GFP) fused to NoLS of AcMNPV LEF5 localized to the nucleoli of transfected cells. Multiple-point mutation analysis demonstrated that amino acid residues 197 to 204 are important for nucleolar localization of LEF5. To identify whether the NoLS in AcMNPV LEF5 is important for production of viral progeny, a lef5-null AcMNPV bacmid was constructed; several NoLS-mutated LEF5 proteins were reinserted into the lef5-null AcMNPV bacmid with a GFP reporter. The constructs containing point mutations at residues 185 to 189 or 197 to 204 in AcMNPV LEF5 resulted in reduction in production of infectious viral progeny and occlusion body yield in bacmid-transfected cells. Together, these data suggested that AcMNPV LEF5 contains an NoLS, which is important for nucleolar localization of LEF5, progeny production, and occlusion body production.IMPORTANCE Many viruses, including human and plant viruses, target nucleolar functions as part of their infection strategy. However, nucleolar localization for baculovirus proteins has not yet been characterized. In this study, two nucleolar proteins, SfNS and SfFBL, were identified in Sf9 cells. Our results showed that Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infection resulted in redistribution of the nucleoli of infected cells. We demonstrated that AcMNPV late expression factor 5 (LEF5) could localize to the nucleolus and contains a nucleolar localization signal (NoLS), which is important for nucleolar localization of AcMNPV LEF5 and for production of viral progeny and yield of occlusion bodies.
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13
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Bai H, Hu Y, Hu X, Li J, Mu J, Zhou Y, Chen X, Wang Y. Major capsid protein of Autographa californica multiple nucleopolyhedrovirus contributes to the promoter activity of the very late viral genes. Virus Res 2019; 273:197758. [PMID: 31541668 DOI: 10.1016/j.virusres.2019.197758] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/12/2019] [Accepted: 09/13/2019] [Indexed: 01/04/2023]
Abstract
The baculovirus expression vector system (BEVS) is one of the most powerful eukaryotic expression systems. Recombinant protein expression is usually controlled by promoters of the baculovirus very late genes (i.e., polyhedrin and p10); therefore, identifying novel regulatory factors for these promoters is key to increasing BEVS productivity. Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is the viral vector most frequently used in BEVS. VP39 is the major nucleocapsid protein of AcMNPV and plays a pivotal role in nucleocapsid assembly in the nucleus. In this study, we found that knocking out vp39 from the AcMNPV genome resulted in decreased protein abundance of polyhedrin and P10. Further assays revealed that the mRNA transcripts and the promoter activities of polyhedrin and p10 were decreased in the absence of vp39, suggesting that VP39 contributes to the activity of the very late viral gene promoters and may represent a means of optimizing the current BEVS.
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Affiliation(s)
- Huimin Bai
- Department of Basic Medicine and Forensic Medicine, Baotou Medical College, Baotou, China
| | - Yangyang Hu
- Shanghai Public Health Clinical Center, Fudan University, Shanghai, China
| | - Xue Hu
- State Key Lab of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Jing Li
- College of Pharmacy, Nankai University, Tianjin, China
| | - Jingfang Mu
- State Key Lab of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Yuan Zhou
- State Key Lab of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Xinwen Chen
- State Key Lab of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Yun Wang
- State Key Lab of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China.
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14
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Nucleocapsid Assembly of Baculoviruses. Viruses 2019; 11:v11070595. [PMID: 31266177 PMCID: PMC6669607 DOI: 10.3390/v11070595] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/27/2019] [Accepted: 06/30/2019] [Indexed: 01/27/2023] Open
Abstract
The baculovirus nucleocapsid is formed through a rod-like capsid encapsulating a genomic DNA molecule of 80~180 kbp. The viral capsid is a large oligomer composed of many copies of various protein subunits. The assembly of viral capsids is a complex oligomerization process. The timing of expression of nucleocapsid-related proteins, transport pathways, and their interactions can affect the assembly process of preformed capsids. In addition, the selection of viral DNA and the injection of the viral genome into empty capsids are the critical steps in nucleocapsid assembly. This paper reviews the replication and recombination of baculovirus DNA, expression and transport of capsid proteins, formation of preformed capsids, DNA encapsulation, and nucleocapsid formation. This review will provide a basis for further study of the nucleocapsid assembly mechanism of baculovirus.
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15
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Lai Q, Zhu L, Xu L, Yuan M, Wu W, Yang K. AcMNPV PKIP is associated with nucleocapsid of budded virions and involved in nucleocapsid assembly. Virus Res 2019; 268:27-37. [DOI: 10.1016/j.virusres.2019.05.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/20/2019] [Accepted: 05/23/2019] [Indexed: 10/26/2022]
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16
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Fang Z, Que Y, Li J, Zhang Z. The deletion of the AcMNPV ac124 gene resulted in a decrease in chitinase transcription. Virus Res 2019; 263:151-158. [PMID: 30711578 DOI: 10.1016/j.virusres.2019.01.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/30/2019] [Accepted: 01/30/2019] [Indexed: 01/26/2023]
Abstract
The Autographa californica multiple nucleopolyhedrovirus (AcMNPV) ac124 gene has been previously characterized as a viral pathogenicity factor. In this study, an ac124-knockout virus (vAc124KO) was generated to examine the role of the ac124 gene in the context of the AcMNPV genome during infection. Our results showed that the absence of ac124 does not affect the production of budded virus (BV) and occlusion bodies (OBs) in infected Sf9 cells. Western blotting analysis showed that the deletion of ac124 does not affect the temporal expression and the relative levels of GP64, VP39, P6.9, and polyhedrin. qRT-PCR analysis showed that the transcription level of chitinase but not the adjacent cathepsin in vAc124KO infected cells was significantly lower than that of the vAcWT infected cells from 24 to 96 h p.i. Luciferase assays showed that the overexpression of Ac124 could significantly improve the ability of chitinase promoter to initiate reporter genes. Based on the above data, we hypothesize that Ac124 binds to the promoter of chitinase to regulate the expression of chitinase gene.
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Affiliation(s)
- Zhixin Fang
- Department of Laboratory Medicine and Central Laboratories, Guangdong Second Provincial General Hospital, 466 Middle Xingang Road, Guangzhou, 510317, Guangdong, People's Republic of China.
| | - Yi Que
- Department of Medical Melanoma and Sarcoma, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, 651 East Dongfeng Road, Guangzhou, 510060, Guangdong, People's Republic of China
| | - Jie Li
- Department of Laboratory Medicine and Central Laboratories, Guangdong Second Provincial General Hospital, 466 Middle Xingang Road, Guangzhou, 510317, Guangdong, People's Republic of China
| | - Zhi Zhang
- Department of Laboratory Medicine and Central Laboratories, Guangdong Second Provincial General Hospital, 466 Middle Xingang Road, Guangzhou, 510317, Guangdong, People's Republic of China.
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17
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The 38K-Mediated Specific Dephosphorylation of the Viral Core Protein P6.9 Plays an Important Role in the Nucleocapsid Assembly of Autographa californica Multiple Nucleopolyhedrovirus. J Virol 2018; 92:JVI.01989-17. [PMID: 29444944 PMCID: PMC5899202 DOI: 10.1128/jvi.01989-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Accepted: 02/07/2018] [Indexed: 02/02/2023] Open
Abstract
Encapsidation of the viral genomes, leading to the assembly of the nucleocapsids to form infectious progeny virions, is a key step in many virus life cycles. Baculovirus nucleocapsid assembly is a complex process that involves many proteins. Our previous studies showed that the deletion of the core gene 38K (ac98) interrupted the nucleocapsid assembly by producing capsid sheaths devoid of viral genomes by an unknown mechanism. All homologs of 38K contain conserved motifs of the haloacid dehalogenase superfamily, which are involved in phosphoryl transfer. The requirements of these motifs for nucleocapsid assembly, confirmed in the present study, suggest that 38K may be a functioning haloacid dehalogenase. P6.9 is also encoded by a core gene (ac100) and is required for viral genome encapsidation. It has been reported that multiple phosphorylated species of P6.9 are present in virus-infected cells, while only an unphosphorylated species is detected in the budded virus. Therefore, whether 38K mediates the dephosphorylation of P6.9 was investigated. An additional phosphorylated species of P6.9 in 38K-deleted or -mutated virus-transfected cells was detected, and the dephosphorylated sites mediated by 38K were determined by mass spectrometry. To assess the effects of dephosphorylation of P6.9 mediated by 38K on virus replication, these sites were mutated to glutamic acids (phosphorylation-mimic mutant) or to alanines (phosphorylation-deficient mutant). Studies showed that the nucleocapsid assembly was interrupted in phosphorylation-mimic mutant virus-transfected cells. Taken together, our findings demonstrate that 38K mediates the dephosphorylation of specific sites at the C terminus of P6.9, which is essential for viral genome encapsidation.IMPORTANCE Genome packaging is a fundamental process in the virus life cycle, and viruses have different strategies to perform this step. For several double-stranded DNA (dsDNA) viruses, the procapsid is formed before genome encapsidation, which may require basic proteins that help to neutralize the nucleic acid charge repulsion to facilitate the compaction of the genome within the confined capsid space. Baculovirus encodes a small basic protein, P6.9, which is required for a variety of processes in the virus infection cycle. The phosphorylation of P6.9 is thought to result in nucleocapsid uncoating, while the dephosphorylation of P6.9 is involved in viral DNA encapsidation during nucleocapsid assembly. Here, we demonstrate that a haloacid dehalogenase homolog encoded by baculovirus core gene 38K is involved in nucleocapsid assembly by mediating the dephosphorylation of 5 specific sites at the C terminus of P6.9. This finding contributes to the understanding of the mechanisms of virus nucleocapsid assembly.
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18
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Zhang J, Feng M, Fan Y, Xu W, Zheng Q, Wu X. Networks of protein-protein interactions among structural proteins of budded virus of Bombyx mori nucleopolyhedrovirus. Virology 2018; 518:163-171. [PMID: 29510333 DOI: 10.1016/j.virol.2018.02.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Revised: 02/15/2018] [Accepted: 02/16/2018] [Indexed: 10/17/2022]
Abstract
The structural proteins of baculovirus are well studied, but the interactions between them remain unclear. In order to reveal protein-protein interactions among viral structural proteins and their associated proteins of the budded virus of Bombyx mori nucleopolyhedrovirus (BmNPV), the yeast two hybrid (Y2H) system was used to evaluate the interactions of 27 viral genes products. Fifty-seven interactions were identified with 51 binary interactions and 6 self-associations. Among them, 10 interactions were further confirmed by co-immunoprecipitation assays. Five interaction networks were formed based on the direct-cross Y2H assays. VP39, 38 K, and FP were identified to interact with most of the viral proteins, and may form major structural elements of the viral architecture. In addition, each envelope protein was detected to interact with more than one capsid protein. These results suggest how viral structural and structural associated proteins may assemble to form a complete virus through interacting with each other.
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Affiliation(s)
- Jianjia Zhang
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Min Feng
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Ying Fan
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Weifan Xu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Qin Zheng
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China
| | - Xiaofeng Wu
- College of Animal Sciences, Zhejiang University, Hangzhou 310058, China.
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19
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Autographa californica Multiple Nucleopolyhedrovirus ac75 Is Required for the Nuclear Egress of Nucleocapsids and Intranuclear Microvesicle Formation. J Virol 2018; 92:JVI.01509-17. [PMID: 29212928 DOI: 10.1128/jvi.01509-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 11/27/2017] [Indexed: 01/15/2023] Open
Abstract
Autographa californica multiple nucleopolyhedrovirus (AcMNPV) orf75 (ac75) is a highly conserved gene of unknown function. In this study, we constructed an ac75 knockout AcMNPV bacmid and investigated the role of ac75 in the baculovirus life cycle. The expression and distribution of the Ac75 protein were characterized, and its interaction with another viral protein was analyzed to further understand its function. Our data indicated that ac75 was required for the nuclear egress of nucleocapsids, intranuclear microvesicle formation, and subsequent budded virion (BV) formation, as well as occlusion-derived virion (ODV) envelopment and embedding of ODVs into polyhedra. Western blot analyses showed that two forms, of 18 and 15 kDa, of FLAG-tagged Ac75 protein were detected. Ac75 was associated with both nucleocapsid and envelope fractions of BVs but with only the nucleocapsid fraction of ODVs; the 18-kDa form was associated with only BVs, whereas the 15-kDa form was associated with both types of virion. Ac75 was localized predominantly in the intranuclear ring zone during infection and exhibited a nuclear rim distribution during the early phase of infection. A phase separation assay suggested that Ac75 was not an integral membrane protein. A coimmunoprecipitation assay revealed an interaction between Ac75 and the integral membrane protein Ac76, and bimolecular fluorescence complementation assays identified the sites of the interaction within the cytoplasm and at the nuclear membrane and ring zone in AcMNPV-infected cells. Our results have identified ac75 as a second gene that is required for both the nuclear egress of nucleocapsids and the formation of intranuclear microvesicles.IMPORTANCE During the baculovirus life cycle, the morphogenesis of both budded virions (BVs) and occlusion-derived virions (ODVs) is proposed to involve a budding process at the nuclear membrane, which occurs while nucleocapsids egress from the nucleus or when intranuclear microvesicles are produced. However, the exact mechanism of virion morphogenesis remains unknown. In this study, we identified ac75 as a second gene, in addition to ac93, that is essential for the nuclear egress of nucleocapsids, intranuclear microvesicle formation, and subsequent BV formation, as well as ODV envelopment and embedding of ODVs into polyhedra. Ac75 is not an integral membrane protein. However, it interacts with an integral membrane protein (Ac76) and is associated with the nuclear membrane. These data enhance our understanding of the commonalities between nuclear egress of nucleocapsids and intranuclear microvesicle formation and may help to reveal insights into the mechanism of baculovirus virion morphogenesis.
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20
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Liang C, Su X, Xu G, Dai X, Zhao S. Autographa californica multiple nucleopolyhedrovirus PK1 is a factor that regulates high-level expression of very late genes in viral infection. Virology 2017; 512:56-65. [DOI: 10.1016/j.virol.2017.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Revised: 09/05/2017] [Accepted: 09/06/2017] [Indexed: 11/28/2022]
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21
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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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22
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Shobahah J, Xue S, Hu D, Zhao C, Wei M, Quan Y, Yu W. Quantitative phosphoproteome on the silkworm (Bombyx mori) cells infected with baculovirus. Virol J 2017. [PMID: 28629377 PMCID: PMC5477107 DOI: 10.1186/s12985-017-0783-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Background Bombyx mori has become an important model organism for many fundamental studies. Bombyx mori nucleopolyhedrovirus (BmNPV) is a significant pathogen to Bombyx mori, yet also an efficient vector for recombinant protein production. A previous study indicated that acetylation plays many vital roles in several cellular processes of Bombyx mori while global phosphorylation pattern upon BmNPV infection remains elusive. Method Employing tandem mass tag (TMT) labeling and phosphorylation affinity enrichment followed by high-resolution LC-MS/MS analysis and intensive bioinformatics analysis, the quantitative phosphoproteome in Bombyx mori cells infected by BmNPV at 24 hpi with an MOI of 10 was extensively examined. Results Totally, 6480 phosphorylation sites in 2112 protein groups were identified, among which 4764 sites in 1717 proteins were quantified. Among the quantified proteins, 81 up-regulated and 25 down-regulated sites were identified with significant criteria (the quantitative ratio above 1.3 was considered as up-regulation and below 0.77 was considered as down-regulation) and with significant p-value (p < 0.05). Some proteins of BmNPV were also hyperphosphorylated during infection, such as P6.9, 39 K, LEF-6, Ac58-like protein, Ac82-like protein and BRO-D. Conclusion The phosphorylated proteins were primary involved in several specific functions, out of which, we focused on the binding activity, protein synthesis, viral replication and apoptosis through kinase activity.
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Affiliation(s)
- Jauharotus Shobahah
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China.,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China
| | - Shengjie Xue
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China.,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China
| | - Dongbing Hu
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China.,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China
| | - Cui Zhao
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China.,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China
| | - Ming Wei
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China.,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China
| | - Yanping Quan
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China.,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China
| | - Wei Yu
- Institute of Biochemistry, College of Life Sciences, Zhejiang Sci-Tech University, Xiasha High-Tech Zone No.2 Road, Zhejiang Province, Hangzhou, 310018, People's Republic of China. .,Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou, 310018, People's Republic of China.
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23
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Flatt JW, Greber UF. Viral mechanisms for docking and delivering at nuclear pore complexes. Semin Cell Dev Biol 2017; 68:59-71. [PMID: 28506891 DOI: 10.1016/j.semcdb.2017.05.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 05/11/2017] [Indexed: 12/22/2022]
Abstract
Some viruses possess the remarkable ability to transport their genomes across nuclear pore complexes (NPCs) for replication inside the host cell's intact nuclear compartment. Viral mechanisms for crossing the restrictive NPC passageway are highly complex and astonishingly diverse, requiring in each case stepwise interaction between incoming virus particles and components of the nuclear transport machinery. Exactly how a large viral genome loaded with accessory proteins is able to pass through the relatively narrow central channel of the NPC without causing catastrophic structural damage is not yet fully understood. It appears likely, however, that the overall structure of the NPC changes in response to the cargo. Translocation may result in nucleic acids being misdelivered to the cytoplasm. Here we consider in detail the diverse strategies that viruses have evolved to target and subvert NPCs during infection. For decades, this process has both captivated and confounded researchers in the fields of virology, cell biology, and structural biology.
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Affiliation(s)
- Justin W Flatt
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Urs F Greber
- Department of Molecular Life Sciences, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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24
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A Conserved Glycine Residue Is Required for Proper Functioning of a Baculovirus VP39 Protein. J Virol 2017; 91:JVI.02253-16. [PMID: 28077638 DOI: 10.1128/jvi.02253-16] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 12/29/2016] [Indexed: 01/25/2023] Open
Abstract
The baculovirus VP39 protein is a major nucleocapsid protein essential for viral propagation. However, the critical domains or residues of the VP39 protein have not yet been identified. Here, we performed mutagenesis experiments with Bombyx mori nucleopolyhedrovirus (BmNPV) using 5-bromo-2'-deoxyuridine and isolated a BmNPV mutant that produced fewer occlusion bodies than the wild-type virus. This mutant also produced fewer infectious budded viruses (BVs) than the wild-type virus in both cultured cells and B. mori larvae. Marker rescue experiments using genomic libraries identified a single nucleotide mutation in the vp39 gene. This mutation resulted in an amino acid substitution at glycine 276 (Gly-276) to serine, which was required for all the defective phenotypes observed in the mutant. Sequence comparison revealed that this residue is completely conserved among the VP39 proteins of the sequenced alphabaculoviruses, betabaculoviruses, and gammabaculoviruses. Although early viral gene expression was not significantly affected, the level of expression of a late gene, vcath, was reduced. In addition, two of the very late genes were markedly downregulated in cells infected with this mutant. Western blot and quantitative PCR analyses revealed that the BVs produced from cells infected with this mutant contained smaller amounts of the VP39 protein and viral genomic DNA than those produced from wild-type virus-infected cells. Combined with the results of transmission electron microscopy, VP39 Gly-276 can be concluded to be essential for correct nucleocapsid assembly, viral DNA packaging, and viral gene expression, especially of very late genes.IMPORTANCE The major nucleocapsid protein gene vp39 is one of the most well-known baculovirus genes. Although several viral and host proteins that interact with the VP39 protein have been identified, the functionally important domains or residues of this protein remain unknown. The present study revealed that the glycine residue at residue 276, which is completely conserved among sequenced alphabaculoviruses, betabaculoviruses, and gammabaculoviruses, is important for the VP39 function, i.e., structural assembly of nucleocapsids and viral DNA packaging. Moreover, our results provide evidence for the link between nucleocapsid formation and the transcription of viral very late genes.
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25
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Shang M, Xie Z, Tang Z, He L, Wang X, Wang C, Wu Y, Li Y, Zhao L, Lv Z, Wu Z, Huang Y, Yu X, Li X. Expression of Clonorchis sinensis GIIIsPLA 2 protein in baculovirus-infected insect cells and its overexpression facilitating epithelial-mesenchymal transition in Huh7 cells via AKT pathway. Parasitol Res 2017; 116:1307-1316. [PMID: 28220242 DOI: 10.1007/s00436-017-5409-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 02/12/2017] [Indexed: 12/29/2022]
Abstract
Although prior studies confirmed that group III secretory phospholipase A2 of Clonorchis sinensis (CsGIIIsPLA2) had stimulating effect on liver fibrosis by binding to LX-2 cells, large-scale expression of recombinant protein and its function in the progression of hepatoma are worth exploring. Because of high productivity and low lipopolysaccharides (LPS) in the Sf9-baculovirus expression system, we firstly used this system to express the coding region of CsGIIIsPLA2. The molecular weight of recombinant CsGIIIsPLA2 protein was about 34 kDa. Further investigation showed that most of the recombinant protein presented intracellular expression in Sf9 insect cell nucleus and could be detected only into cell debris, which made the protein purification and further functional study difficult. Therefore, to study the role of CsGIIIsPLA2 in hepatocellular carcinoma (HCC) progression, CsGIIIsPLA2 overexpression Huh7 cell model was applied. Cell proliferation, migration, and the expression level of epithelial-mesenchymal transition (EMT)-related molecules (E-cadherin, N-cadherin, α-catenin, Vimentin, p300, Snail, and Slug) along with possible mechanism were measured. The results indicated that CsGIIIsPLA2 overexpression not only inhibited cell proliferation and promoted migration and EMT but also enhanced the phosphorylation of AKT in HCC cells. In conclusion, this study supported that CsGIIIsPLA2 overexpression suppressed cell proliferation and induced EMT through the AKT pathway.
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Affiliation(s)
- Mei Shang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Zhizhi Xie
- Department of Clinical Laboratory, Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Zeli Tang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Lei He
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Department of Clinical Laboratory, Guangzhou Red Cross Hospital, Medical College, Jinan University, Guangzhou, 510060, People's Republic of China
| | - Xiaoyun Wang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Caiqin Wang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Yinjuan Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Ye Li
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Lu Zhao
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Zhiyue Lv
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Zhongdao Wu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Yan Huang
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Xinbing Yu
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China
| | - Xuerong Li
- Department of Parasitology, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China. .,Key Laboratory for Tropical Diseases Control, Ministry of Education, Sun Yat-Sen University, Guangzhou, 510080, People's Republic of China.
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26
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The Autographa californica Multiple Nucleopolyhedrovirus ac83 Gene Contains a cis-Acting Element That Is Essential for Nucleocapsid Assembly. J Virol 2017; 91:JVI.02110-16. [PMID: 28031366 DOI: 10.1128/jvi.02110-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Accepted: 12/21/2016] [Indexed: 01/08/2023] Open
Abstract
Baculoviridae is a family of insect-specific viruses that have a circular double-stranded DNA genome packaged within a rod-shaped capsid. The mechanism of baculovirus nucleocapsid assembly remains unclear. Previous studies have shown that deletion of the ac83 gene of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) blocks viral nucleocapsid assembly. Interestingly, the ac83-encoded protein Ac83 is not a component of the nucleocapsid, implying a particular role for ac83 in nucleocapsid assembly that may be independent of its protein product. To examine this possibility, Ac83 synthesis was disrupted by insertion of a chloramphenicol resistance gene into its coding sequence or by deleting its promoter and translation start codon. Both mutants produced progeny viruses normally, indicating that the Ac83 protein is not required for nucleocapsid assembly. Subsequently, complementation assays showed that the production of progeny viruses required the presence of ac83 in the AcMNPV genome instead of its presence in trans Therefore, we reasoned that ac83 is involved in nucleocapsid assembly via an internal cis-acting element, which we named the nucleocapsid assembly-essential element (NAE). The NAE was identified to lie within nucleotides 1651 to 1850 of ac83 and had 8 conserved A/T-rich regions. Sequences homologous to the NAE were found only in alphabaculoviruses and have a conserved positional relationship with another essential cis-acting element that was recently identified. The identification of the NAE may help to connect the data of viral cis-acting elements and related proteins in the baculovirus nucleocapsid assembly, which is important for elucidating DNA-protein interaction events during this process.IMPORTANCE Virus nucleocapsid assembly usually requires specific cis-acting elements in the viral genome for various processes, such as the selection of the viral genome from the cellular nucleic acids, the cleavage of concatemeric viral genome replication intermediates, and the encapsidation of the viral genome into procapsids. In linear DNA viruses, such elements generally locate at the ends of the viral genome; however, most of these elements remain unidentified in circular DNA viruses (including baculovirus) due to their circular genomic conformation. Here, we identified a nucleocapsid assembly-essential element in the AcMNPV (the archetype of baculovirus) genome. This finding provides an important reference for studies of nucleocapsid assembly-related elements in baculoviruses and other circular DNA viruses. Moreover, as most of the previous studies of baculovirus nucleocapsid assembly have been focused on viral proteins, our study provides a novel entry point to investigate this mechanism via cis-acting elements in the viral genome.
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Zhao C, Zhang C, Chen B, Shi Y, Quan Y, Nie Z, Zhang Y, Yu W. A DNA Binding Protein Is Required for Viral Replication and Transcription in Bombyx mori Nucleopolyhedrovirus. PLoS One 2016; 11:e0159149. [PMID: 27414795 PMCID: PMC4945074 DOI: 10.1371/journal.pone.0159149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/28/2016] [Indexed: 11/18/2022] Open
Abstract
A DNA-binding protein (DBP) [GenBank accession number: M63416] of Bombyx mori nuclear polyhedrosis virus (BmNPV) has been reported to be a regulatory factor in BmNPV, but its detailed functions remain unknown. In order to study the regulatory mechanism of DBP on viral proliferation, genome replication, and gene transcription, a BmNPV dbp gene knockout virus dbp-ko-Bacmid was generated by the means of Red recombination system. In addition, dbp-repaired virus dbp-re-Bacmid was constructed by the means of the Bac to Bac system. Then, the Bacmids were transfected into BmN cells. The results of this viral titer experiment revealed that the TCID50 of the dbp-ko-Bacmid was 0; however, the dbp-re-Bacmid was similar to the wtBacmid (p>0.05), indicating that the dbp-deficient would lead to failure in the assembly of virus particles. In the next step, Real-Time PCR was used to analyze the transcriptional phases of dbp gene in BmN cells, which had been infected with BmNPV. The results of the latter experiment revealed that the transcript of dbp gene was first detected at 3 h post-infection. Furthermore, the replication level of virus genome and the transcriptional level of virus early, late, and very late genes in BmN cells, which had been transfected with 3 kinds of Bacmids, were analyzed by Real-Time PCR. The demonstrating that the replication level of genome was lower than that of wtBacmid and dbp-re-Bacmid (p<0.01). The transcriptional level of dbp-ko-Bacmid early gene lef-3, ie-1, dnapol, late gene vp39 and very late gene p10 were statistically significantly lower than dbp-re-Bacmid and wtBacmid (p<0.01). The results presented are based on Western blot analysis, which indicated that the lack of dbp gene would lead to low expressions of lef3, vp39, and p10. In conclusion, dbp was not only essential for early viral replication, but also a viral gene that has a significant impact on transcription and expression during all periods of baculovirus life cycle.
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Affiliation(s)
- Cui Zhao
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Chen Zhang
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Bin Chen
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Yanghui Shi
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Yanping Quan
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Zuoming Nie
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Yaozhou Zhang
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
| | - Wei Yu
- College of life sciences, Zhejiang Sci-Tech University, Zhejiang Province, Hangzhou 310018, China
- Zhejiang Provincial Key Laboratory of Silkworm Bioreactor and Biomedicine, Zhejiang Province, Hangzhou 310018, China
- * E-mail:
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The Autographa californica Multiple Nucleopolyhedrovirus ac54 Gene Is Crucial for Localization of the Major Capsid Protein VP39 at the Site of Nucleocapsid Assembly. J Virol 2016; 90:4115-4126. [PMID: 26865720 DOI: 10.1128/jvi.02885-15] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2015] [Accepted: 02/02/2016] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED Baculovirus DNAs are synthesized and inserted into preformed capsids to form nucleocapsids at a site in the infected cell nucleus, termed the virogenic stroma. Nucleocapsid assembly ofAutographa californicamultiple nucleopolyhedrovirus (AcMNPV) requires the major capsid protein VP39 and nine minor capsid proteins, including VP1054. However, how VP1054 participates in nucleocapsid assembly remains elusive. In this study, the VP1054-encoding gene (ac54) was deleted to generate theac54-knockout AcMNPV (vAc54KO). In vAc54KO-transfected cells, nucleocapsid assembly was disrupted, leading to the formation of abnormally elongated capsid structures. Interestingly, unlike cells transfected with AcMNPV mutants lacking other minor capsid proteins, in which capsid structures were distributed within the virogenic stroma,ac54ablation resulted in a distinctive location of capsid structures and VP39 at the periphery of the nucleus. The altered distribution pattern of capsid structures was also observed in cells transfected with AcMNPV lacking BV/ODV-C42 or in cytochalasind-treated AcMNPV-infected cells. BV/ODV-C42, along with PP78/83, has been shown to promote nuclear filamentous actin (F-actin) formation, which is another requisite for nucleocapsid assembly. Immunofluorescence using phalloidin indicated that the formation and distribution of nuclear F-actin were not affected byac54deletion. However, immunoelectron microscopy revealed that BV/ODV-C42, PP78/83, and 38K failed to integrate into capsid structures in the absence of VP1054, and immunoprecipitation further demonstrated that in transient expression assays, VP1054 interacted with BV/ODV-C42 and VP80 but not VP39. Our findings suggest that VP1054 plays an important role in the transport of capsid proteins to the nucleocapsid assembly site prior to the process of nucleocapsid assembly. IMPORTANCE Baculoviruses are large DNA viruses whose replication occurs within the host nucleus. The localization of capsids into the capsid assembly site requires virus-induced nuclear F-actin; the inhibition of nuclear F-actin formation results in the retention of capsid structures at the periphery of the nucleus. In this paper, we note that the minor capsid protein VP1054 is essential for the localization of capsid structures, the major capsid protein VP39, and the minor capsid protein 38K into the capsid assembly site. Moreover, VP1054 is crucial for correct targeting of the nuclear F-actin factors BV/ODV-C42 and PP78/83 for capsid maturation. However, the formation and distribution of nuclear F-actin are not affected by the lack of VP1054. We further reveal that VP1054 interacts with BV/ODV-C42 and a capsid transport-related protein, VP80. Taken together, our findings suggest that VP1054 plays a unique role in the pathway(s) for transport of capsid proteins.
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