1
|
Zhao Z, Yue D, Ye B, Li P, Li W, Wang L, Zhang B, Fan Q. Functional analyses of inhibitor of apoptosis protein 1 (IAP1) of Antheraea pernyi multinucleocapsid nucleopolyhedrovirus (AnpeNPV) in viral replication and occlusion body production. J Invertebr Pathol 2022; 194:107816. [PMID: 35964678 DOI: 10.1016/j.jip.2022.107816] [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: 03/06/2022] [Revised: 07/28/2022] [Accepted: 08/07/2022] [Indexed: 11/24/2022]
Abstract
Inhibitor of apoptosis protein 1 (IAP1) of Antheraea pernyi multinucleocapsid nucleopolyhedrovirus (AnpeNPV) belongs to the baculovirus IAP1 type. The function of AnpeNPV-IAP1 in viral replication and occlusion body (OB) production remains unknown. In this study, we demonstrated that AnpeNPV-iap1 is a late gene. AnpeNPV-IAP1 mainly localizes to the nuclear ring zone and exhibits dynamic distribution in the cytoplasm and the virogenic stroma during AnpeNPV infection. AnpeNPV-IAP1 impacted the expression of a variety of viral genes at the very late phase of infection in Tn-Hi5 cells. The deletion of AnpeNPV-iap1 caused decreased expression levels of polyhedrin, morphological changes to OBs and reduced OB production in A. pernyi pupae, along with a lengthening of the lethal time of A. pernyi larvae. These results suggest that AnpeNPV-iap1 is involved in regulating viral gene expression, OB production and morphogenesis in A. pernyi.
Collapse
Affiliation(s)
- Zhenjun Zhao
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China
| | - Dongmei Yue
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China
| | - Bo Ye
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China
| | - Peipei Li
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China
| | - Wenli Li
- School of Life and Pharmaceutical Sciences, Dalian University of Technology, Panjin 124211, China
| | - Linmei Wang
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China
| | - Bo Zhang
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China
| | - Qi Fan
- Liaoning Ocean and Fisheries Science Research Institute, Liaoning Academy of Agricultural Sciences, Dalian 116023, China.
| |
Collapse
|
2
|
Zheng H, Pan Y, Awais MM, Tian W, Li J, Sun J. Impact of Group II Baculovirus IAPs on Virus-Induced Apoptosis in Insect Cells. Genes (Basel) 2022; 13:genes13050750. [PMID: 35627135 PMCID: PMC9140827 DOI: 10.3390/genes13050750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/19/2022] [Accepted: 04/22/2022] [Indexed: 12/10/2022] Open
Abstract
Apoptosis plays an important role in virus-host interactions and is a major element of the insect immune response. Exploring the regulatory mechanisms of virus-induced apoptosis through the expression of apoptotic genes holds important research and application value. Functional research on the reported inhibitor of apoptosis proteins (IAPs) mainly focuses on the group I baculovirus, while the functions of the group II baculovirus IAPs remains unclear. To explore its role in the regulation of the apoptosis of insect cells, we constructed the transient expression vector (pIE1 vectors) and the recombinant baculovirus expressing Bsiap genes (from the Buzura suppressaria nucleopolyhedrovirus) of the group II baculovirus. Apoptosis gene expression results and the virus-induced apoptosis rate show that the overexpression of BsIAP1 could promote apoptosis in insect cells. However, the overexpression of BsIAP2 and BsIAP3 decreases the expression of apoptotic genes, revealing an inhibitory effect. Results on the impact of baculovirus-induced apoptosis also confirm that BsIAP1 reduces viral nucleocapsid expression and the baculovirus titer, while BsIAP2 and BsIAP3 increase them significantly. Furthermore, compared with single expression, the co-expression of BsIAP2 and BsIAP3 significantly reduces the rate of virus-induced apoptosis and improves the expression of nucleocapsids and the titer of offspring virus, indicating the synergistic effect on BsIAP2 and BsIAP3. In addition, combined expression of all three BsIAPs significantly reduced levels of intracellular apoptosis-related genes (including apoptosis and anti-apoptosis genes), as well as apoptosis rate and progeny virus titer, indicating that life activities in insect cells are also inhibited. These findings reveal the relationship between apoptosis and group II baculovirus IAP, which provide an experimental and theoretical basis for further exploration of the molecular mechanism between group II baculoviruses and insect cells.
Collapse
|
3
|
Silva AM, Morgado FS, Silva LA, Borges JRJ, Perecmanis S, Ardisson-Araújo DMP, Ribeiro BM, Campos FS. Evaluation of the anti-apoptotic activity of bovine alphaherpesvirus type 5 US3 protein kinase in insect cells using a recombinant baculovirus. Braz J Microbiol 2020; 51:827-835. [PMID: 31907798 DOI: 10.1007/s42770-019-00215-x] [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: 08/24/2019] [Accepted: 12/14/2019] [Indexed: 10/25/2022] Open
Abstract
Bovine alphaherpesvirus type 5 (BoHV-5) is one of the main agents responsible for meningoencephalitis in cattle in Brazil, causing significant economic losses. It is known that other viruses of the Herpesviridae family such as Bovine alphaherpesvirus type 1, Swine alphaherpesvirus type 1, and the Human alphaherpesvirus types 1 and 2 encode genes homologous to BoHV-5, with recognized action in the control of apoptosis. The objective of this work was to express the BoHV-5 US3 gene in a baculovirus-based expression system for the production of the serine/threonine kinase protein and to evaluate its activity in the control of apoptosis in vitro. A recombinant baculovirus derived from the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) containing the US3 gene and a deletion in the baculovirus anti-apoptotic p35 gene was constructed using the Bac-to-Bac™ system. This recombinant baculovirus was used to evaluate the anti-apoptotic activity of the recombinant US3 protein in insect cells comparing with two other AcMNPV recombinants, one containing a functional copy of the AcMNPV anti-apoptotic p35 gene and an AcMNPV p35 knockout virus with the anti-apoptotic iap-3 gene from Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV). We found that the caspase level was higher in insect cells infected with the US3-contanining recombinant virus than in cells infected with the AcMNPV recombinants containing the p35 and iap-3 genes. These results indicate that the BoHV-5 US3 protein kinase gene is not able to block apoptosis in insect cells induced by the infection of a p35 knockout AcMNPV.
Collapse
Affiliation(s)
- Alice M Silva
- Laboratory of Veterinary Microbiology, Faculty of Veterinary Medicine and Agronomy, University of Brasília, Brasília, DF, Brazil
| | - Fabrício S Morgado
- Laboratory of Baculovirus, Cell Biology Department, University of Brasília, Brasília, DF, Brazil
| | - Leonardo A Silva
- Laboratory of Baculovirus, Cell Biology Department, University of Brasília, Brasília, DF, Brazil
| | - José R J Borges
- Veterinary Hospital, Faculty of Veterinary Medicine and Agronomy, University of Brasília, Brasília, DF, Brazil
| | - Simone Perecmanis
- Laboratory of Veterinary Microbiology, Faculty of Veterinary Medicine and Agronomy, University of Brasília, Brasília, DF, Brazil
| | - Daniel M P Ardisson-Araújo
- Departament of Biochemistry and Molecular Biology, Federal University of Santa Maria, Santa Maria, RS, Brazil
| | - Bergmann M Ribeiro
- Laboratory of Baculovirus, Cell Biology Department, University of Brasília, Brasília, DF, Brazil
| | - Fabrício S Campos
- Laboratory of Bioinformatics and Biotechnology, Federal University of Tocantins, Campus of Gurupi, Gurupi, TO, Brazil.
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Chang JC, Chang ZT, Huang YF, Lee SJ, Kim JS, Nai YS. Characterization and functional assay of apsup (Lyxy105) from Lymantria xylina multiple nucleopolyhedrovirus (LyxyMNPV). Virus Genes 2018; 54:578-586. [PMID: 29876768 DOI: 10.1007/s11262-018-1580-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 06/01/2018] [Indexed: 11/29/2022]
Abstract
The baculoviral anti-apoptotic genes, p35 and iap (inhibitor of apoptosis), play important roles in the initiation of viral infection. Recently, a new anti-apoptotic gene (apoptosis suppressor, apsup) was identified in Lymantria dispar multiple nucleopolyhedrovirus (LdMNPV). An apsup homolog gene, Lyxy105 (ly-apsup), was also predicted in the Lymantria xylina multiple nucleopolyhedrovirus (LyxyMNPV) genome. In this study, we attempt to perform a gene expression analysis and a functional assay of ly-apsup to demonstrate its anti-apoptotic activity and identify the functional domain of this protein. The transcription of the ly-apsup gene region was detected from 12 h post-infection (hpi) and increased significantly after 24-72 hpi. Comparison of the putative amino acid sequences to those of 18 baculoviral homolog proteins showed high amino acid identity to the LdMNPV sequences. Moreover, five conserved protein domains (named as domains I-V) were found. Therefore, protein functional assays were conducted on full-length proteins and different truncation clones. The overexpression of each clone was confirmed by western blot analysis, and the data revealed that a cleavage of ~ 5 kDa at the N-terminal region of the full-length, domains I-IV (1-241) and I-III (1-178), proteins occurred. The results of the functional analysis showed that full-length Ly-apsup and Ly-apsup with domain I (1-70) could inhibit Drosophila-RPR protein (D-RPR)-induced and actinomycin D (ActD)-induced apoptoses. In addition, the domains I and I-II (1-126) regions showed higher anti-apoptotic activity than the other domains in both D-RPR-induced and ActD-induced cell apoptoses. In conclusion, domain I of Ly-apsup may play an important role in the anti-apoptotic activity of this protein; cleavage of the Ly-apsup N-terminus may lead to decreased anti-apoptotic activity.
Collapse
Affiliation(s)
- Ju-Chun Chang
- Depatment of Biotechnology and Animal Science, National Ilan University, Yilan, Taiwan, ROC
| | - Zih-Ting Chang
- Depatment of Biotechnology and Animal Science, National Ilan University, Yilan, Taiwan, ROC
| | - Yu-Feng Huang
- Genomic Research Center, Academia Sinica, Taipei, Taiwan, ROC
| | - Se Jin Lee
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, 54596, South Korea
| | - Jae Su Kim
- Department of Agricultural Biology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju, 54596, South Korea.,Plant Medical Research Center, College of Agricultural and Life Sciences, Chonbuk National University, Jenoju, 54596, South Korea
| | - Yu-Shin Nai
- Depatment of Biotechnology and Animal Science, National Ilan University, Yilan, Taiwan, ROC.
| |
Collapse
|
6
|
Geng P, Li W, de Miranda JR, Qian Z, An L, Terenius O. Studies on the transmission and tissue distribution of Antheraea pernyi iflavirus in the Chinese oak silkmoth Antheraea pernyi. Virology 2017; 502:171-175. [DOI: 10.1016/j.virol.2016.12.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 11/15/2016] [Accepted: 12/13/2016] [Indexed: 11/29/2022]
|
7
|
Viral IAPs, then and now. Semin Cell Dev Biol 2015; 39:72-9. [DOI: 10.1016/j.semcdb.2015.01.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 01/22/2015] [Accepted: 01/23/2015] [Indexed: 11/22/2022]
|
8
|
Ikeda M, Yamada H, Hamajima R, Kobayashi M. Baculovirus genes modulating intracellular innate antiviral immunity of lepidopteran insect cells. Virology 2013; 435:1-13. [DOI: 10.1016/j.virol.2012.10.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/08/2012] [Accepted: 10/08/2012] [Indexed: 12/11/2022]
|
9
|
Baculovirus Lymantria dispar multiple nucleopolyhedrovirus IAP2 and IAP3 do not suppress apoptosis, but trigger apoptosis of insect cells in a transient expression assay. Virus Genes 2012; 45:370-9. [PMID: 22798056 DOI: 10.1007/s11262-012-0783-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Accepted: 07/03/2012] [Indexed: 10/28/2022]
Abstract
Ld652Y cells derived from the gypsy moth, Lymantria dispar, are permissive for productive infection with L. dispar multiple nucleopolyhedrovirus (LdMNPV), but undergo apoptosis upon infection with various other NPVs, including those isolated from Bombyx mori, Hyphantria cunea, Spodoptera exigua, Orgyia pseudotsugata, and Spodoptera litura. In this study, we examined whether LdMNPV-encoded inhibitor of apoptosis 2 (Ld-IAP2) and 3 (Ld-IAP3) are involved in apoptosis suppression in LdMNPV-infected Ld652Y cells. We found that neither Ld-IAP2 nor Ld-IAP3 was able to suppress the apoptosis of Ld652Y cells induced by p35-defective Autographa californica MNPV (vAcΔp35). However, both Ld-IAP2 and Ld-IAP3 induced apoptosis in Ld652Y cells in a transient expression assay. The apoptosis induced by Ld-IAP3 was accompanied by the stimulation of caspase-3-like protease activity and cleavage of the B. mori homolog of the initiator caspase Dronc, and was precluded by the LdMNPV-encoded apoptosis suppressor protein Apsup and H. cunea MNPV IAP3. Inconsistent with the results obtained previously in SpIm, Ld652Y and High Five cells infected with NPVs from H. cunea, O. pseudotsugata, and A. californica, respectively, considerable stimulation of caspase-3-like protease activity was not observed in LdMNPV-infected Ld652Y cells, likely due to the strong apoptosis suppression activity of Apsup. These results, together with the previous finding that RNAi-mediated silencing of apsup induces apoptosis of LdMNPV-infected Ld652Y cells, indicate that Apsup, but not Ld-IAP2 or Ld-IAP3, is primarily responsible for the suppression of apoptosis in LdMNPV-infected Ld652Y cells. However, it remains inconclusive whether Ld-IAP2 and Ld-IAP3 function as pro-apoptotic proteins in LdMNPV-infected Ld652Y cells.
Collapse
|
10
|
Thumbi DK, Eveleigh RJM, Lucarotti CJ, Lapointe R, Graham RI, Pavlik L, Lauzon HAM, Arif BM. Complete sequence, analysis and organization of the Orgyia leucostigma nucleopolyhedrovirus genome. Viruses 2011; 3:2301-27. [PMID: 22163346 PMCID: PMC3230853 DOI: 10.3390/v3112301] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 10/25/2011] [Accepted: 10/25/2011] [Indexed: 11/16/2022] Open
Abstract
The complete genome of the Orgyia leucostigma nucleopolyhedrovirus (OrleNPV) isolated from the whitemarked tussock moth (Orgyia leucostigma, Lymantridae: Lepidoptera) was sequenced, analyzed, and compared to other baculovirus genomes. The size of the OrleNPV genome was 156,179 base pairs (bp) and had a G+C content of 39%. The genome encoded 135 putative open reading frames (ORFs), which occupied 79% of the entire genome sequence. Three inhibitor of apoptosis (ORFs 16, 43 and 63), and five baculovirus repeated ORFs (bro-a through bro-e) were interspersed in the OrleNPV genome. In addition to six direct repeat (drs), a common feature shared among most baculoviruses, OrleNPV genome contained three homologous regions (hrs) that are located in the latter half of the genome. The presence of an F-protein homologue and the results from phylogenetic analyses placed OrleNPV in the genus Alphabaculovirus, group II. Overall, OrleNPV appears to be most closely related to group II alphabaculoviruses Ectropis obliqua (EcobNPV), Apocheima cinerarium (ApciNPV), Euproctis pseudoconspersa (EupsNPV), and Clanis bilineata (ClbiNPV).
Collapse
Affiliation(s)
- David K. Thumbi
- Sylvar Technologies Inc., P.O. Box 636 Station A, Fredericton, New Brunswick, E3B 5A6, Canada; E-Mails: (D.K.T.); (R.J.M.E); (R.L.)
| | - Robert J. M. Eveleigh
- Sylvar Technologies Inc., P.O. Box 636 Station A, Fredericton, New Brunswick, E3B 5A6, Canada; E-Mails: (D.K.T.); (R.J.M.E); (R.L.)
| | - Christopher J. Lucarotti
- Natural Resources Canada, Atlantic Forestry Centre, Canadian Forest Service, 1350 Regent Street, Fredericton, New Brunswick, E3C 2G6, Canada
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-506-452-3538; Fax: +1-506-452-3538
| | - Renée Lapointe
- Sylvar Technologies Inc., P.O. Box 636 Station A, Fredericton, New Brunswick, E3B 5A6, Canada; E-Mails: (D.K.T.); (R.J.M.E); (R.L.)
| | - Robert I. Graham
- Lancaster Environment Centre, Lancaster University, Lancaster, Lancashire, LA1 4YQ, UK; E-Mails:
| | - Lillian Pavlik
- Natural Resources Canada, Great Lakes Forestry Centre, Canadian Forest Service, 1219 Queen Street East, Sault Ste. Marie, Ontario, P6A 2E5, Canada; E-Mails: (L.P); (H.A.M.L.); (B.M.A.)
| | - Hilary A. M. Lauzon
- Natural Resources Canada, Great Lakes Forestry Centre, Canadian Forest Service, 1219 Queen Street East, Sault Ste. Marie, Ontario, P6A 2E5, Canada; E-Mails: (L.P); (H.A.M.L.); (B.M.A.)
| | - Basil M. Arif
- Natural Resources Canada, Great Lakes Forestry Centre, Canadian Forest Service, 1219 Queen Street East, Sault Ste. Marie, Ontario, P6A 2E5, Canada; E-Mails: (L.P); (H.A.M.L.); (B.M.A.)
| |
Collapse
|
11
|
Ikeda M, Yamada H, Ito H, Kobayashi M. Baculovirus IAP1 induces caspase-dependent apoptosis in insect cells. J Gen Virol 2011; 92:2654-2663. [PMID: 21795471 DOI: 10.1099/vir.0.033332-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Baculoviruses encode inhibitors of apoptosis (IAPs), which are classified into five groups, IAP1-5, based on their sequence homology. Most of the baculovirus IAPs with anti-apoptotic functions belong to the IAP3 group, with certain exceptions. The functional roles of IAPs from other groups during virus infection have not been well established. We have previously shown that Hyphantria cunea multiple nucleopolyhedrovirus (HycuMNPV) encodes three iap genes, hycu-iap1, hycu-iap2 and hycu-iap3, and that only Hycu-IAP3 has anti-apoptotic activity against actinomycin D-induced apoptosis of Spodoptera frugiperda Sf9 cells. In the present study, we demonstrate that transient expression of Hycu-IAP1 is capable of inducing apoptosis and/or stimulating caspase-3-like protease activity in various lepidopteran and dipteran cell lines. Transient-expression assay analysis also demonstrates that not only Hycu-IAP1 but also IAP1s from Autographa californica MNPV, Bombyx mori NPV and Orgyia pseudotsugata MNPV (OpMNPV) are capable of inducing apoptosis, and that apoptosis induced by Hycu-IAP1 is precluded by the functional anti-apoptotic baculovirus protein Hycu-IAP3. In HycuMNPV-infected Spilosoma imparilis (SpIm) cells and OpMNPV-infected Ld652Y cells, caspase-3-like protease activity is markedly stimulated during the late stages of infection, and the caspase-3-like protease activity stimulated in HycuMNPV-infected SpIm cells is repressed by RNA interference-mediated silencing of hycu-iap1. In addition, initiator caspase Bm-Dronc, the B. mori homologue of Dronc, is cleaved upon transfection of BM-N cells with a plasmid expressing Hycu-IAP1. These results provide the first evidence that baculovirus IAP1s act to induce caspase-dependent apoptosis, possibly by replacing the cellular IAP1 that prevents Dronc activation.
Collapse
Affiliation(s)
- Motoko Ikeda
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Hayato Yamada
- Laboratory of Sericulture and Entomoresources, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Hiroyuki Ito
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Michihiro Kobayashi
- Laboratory of Biodynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya 464-8601, Japan
| |
Collapse
|