1
|
Jia X, Gao Y, Huang Y, Sun L, Li S, Li H, Zhang X, Li Y, He J, Wu W, Venkannagari H, Yang K, Baker ML, Zhang Q. Architecture of the baculovirus nucleocapsid revealed by cryo-EM. Nat Commun 2023; 14:7481. [PMID: 37980340 PMCID: PMC10657434 DOI: 10.1038/s41467-023-43284-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 11/03/2023] [Indexed: 11/20/2023] Open
Abstract
Baculovirus Autographa californica multiple nucleopolyhedrovirus (AcMNPV) has been widely used as a bioinsecticide and a protein expression vector. Despite their importance, very little is known about the structure of most baculovirus proteins. Here, we show a 3.2 Å resolution structure of helical cylindrical body of the AcMNPV nucleocapsid, composed of VP39, as well as 4.3 Å resolution structures of both the head and the base of the nucleocapsid composed of over 100 protein subunits. AcMNPV VP39 demonstrates some features of the HK97-like fold and utilizes disulfide-bonds and a set of interactions at its C-termini to mediate nucleocapsid assembly and stability. At both ends of the nucleocapsid, the VP39 cylinder is constricted by an outer shell ring composed of proteins AC104, AC142 and AC109. AC101(BV/ODV-C42) and AC144(ODV-EC27) form a C14 symmetric inner layer at both capsid head and base. In the base, these proteins interact with a 7-fold symmetric capsid plug, while a portal-like structure is seen in the central portion of head. Additionally, we propose an application of AlphaFold2 for model building in intermediate resolution density.
Collapse
Affiliation(s)
- Xudong Jia
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Yuanzhu Gao
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
- Cryo-EM Facility Center, Southern University of Science and Technology, Shenzhen, China
| | - Yuxuan Huang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Linjun Sun
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Siduo Li
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Hongmei Li
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Xueqing Zhang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Yinyin Li
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Jian He
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Wenbi Wu
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Harikanth Venkannagari
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, TX, 77030, USA
| | - Kai Yang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China
| | - Matthew L Baker
- Department of Biochemistry and Molecular Biology, McGovern Medical School at the University of Texas Health Science Center, Houston, TX, 77030, USA.
| | - Qinfen Zhang
- State key laboratory of biocontrol, School of Life Sciences, Sun Yat-sen University, 510275, Guangzhou, China.
| |
Collapse
|
2
|
Amalfi S, Molina GN, Bevacqua RJ, López MG, Taboga O, Alfonso V. Baculovirus Transduction in Mammalian Cells Is Affected by the Production of Type I and III Interferons, Which Is Mediated Mainly by the cGAS-STING Pathway. J Virol 2020; 94:e01555-20. [PMID: 32796076 PMCID: PMC7565641 DOI: 10.1128/jvi.01555-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 08/05/2020] [Indexed: 12/13/2022] Open
Abstract
The baculovirus Autographa californica multiple nucleopolyhedrovirus is an insect virus with a circular double-stranded DNA genome, which, among other multiple biotechnological applications, is used as an expression vector for gene delivery in mammalian cells. Nevertheless, the nonspecific immune response triggered by viral vectors often suppresses transgene expression. To understand the mechanisms involved in that response, in the present study, we studied the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) pathway by using two approaches: the genetic edition through CRISPR/Cas9 technology of genes encoding STING or cGAS in NIH/3T3 murine fibroblasts and the infection of HEK293 and HEK293 T human epithelial cells, deficient in cGAS and in cGAS and STING expression, respectively. Overall, our results suggest the existence of two different pathways involved in the establishment of the antiviral response, both dependent on STING expression. Particularly, the cGAS-STING pathway resulted in the more relevant production of beta interferon (IFN-β) and IFN-λ1 in response to baculovirus infection. In human epithelial cells, IFN-λ1 production was also induced in a cGAS-independent and DNA-protein kinase (DNA-PK)-dependent manner. Finally, we demonstrated that these cellular responses toward baculovirus infection affect the efficiency of transduction of baculovirus vectors.IMPORTANCE Baculoviruses are nonpathogenic viruses that infect mammals, which, among other applications, are used as vehicles for gene delivery. Here, we demonstrated that the cytosolic DNA sensor cGAS recognizes baculoviral DNA and that the cGAS-STING axis is primarily responsible for the attenuation of transduction in human and mouse cell lines through type I and type III IFNs. Furthermore, we identified DNA-dependent protein kinase (DNA-PK) as a cGAS-independent and alternative DNA cytosolic sensor that contributes less to the antiviral state in baculovirus infection in human epithelial cells than cGAS. Knowledge of the pathways involved in the response of mammalian cells to baculovirus infection will improve the use of this vector as a tool for gene therapy.
Collapse
Affiliation(s)
- Sabrina Amalfi
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Argentina
| | - Guido Nicolás Molina
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Argentina
| | - Romina Jimena Bevacqua
- Laboratorio de Biotecnología Animal, Facultad de Agronomía, Universidad de Buenos Aires/INPA-CONICET, Buenos Aires, Argentina
- Seung Kim Lab, Department of Developmental Biology, Stanford University School of Medicine, Stanford, California, USA
| | - María Gabriela López
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Argentina
| | - Oscar Taboga
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Argentina
| | - Victoria Alfonso
- Instituto de Agrobiotecnología y Biología Molecular (IABIMO), Instituto Nacional de Tecnología Agropecuaria (INTA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Hurlingham, Argentina
| |
Collapse
|