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Zhang D, Yang J, Huang Q, Zhao D, Wang T, Yu D, Qin L, Zhang K. Molecular functions of HAX1 during disease progress. Virus Genes 2024; 60:435-445. [PMID: 38992331 DOI: 10.1007/s11262-024-02081-8] [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: 01/11/2024] [Accepted: 05/29/2024] [Indexed: 07/13/2024]
Abstract
HCLS1-associated protein X-1 (HAX1) is a newly discovered multifunctional cell regulatory protein that is widely expressed in cells and has a close relationship with multiple cellular proteins. HAX1 plays important roles in various processes, including the regulation of apoptosis, maintenance of mitochondrial membrane potential stability and calcium homeostasis, occurrence and development of diseases, post-transcriptional regulation of gene expression, and host immune response after viral infection. In this article, we have reviewed the research progress on the biological functions of HAX1, thereby laying a theoretical foundation for further exploration of its underlying mechanisms and targeted application.
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Affiliation(s)
- Dajun Zhang
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China
| | - Jinke Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, 730000, China
| | - Qi Huang
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China
| | - Dengshuai Zhao
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China
| | - Tianyu Wang
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China
| | - Dixi Yu
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China
| | - Limei Qin
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China.
| | - Keshan Zhang
- College of Life Sciences and Engineering, Foshan University, Foshan, 528225, Guangdong Province, People's Republic of China.
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Yang Y, Jiang G, He W, Tian X, Zheng H, Xiang B, Sun Y. Network of Interactions between the Mut Domains of the E2 Protein of Atypical Porcine Pestivirus and Host Proteins. Genes (Basel) 2024; 15:991. [PMID: 39202352 PMCID: PMC11354059 DOI: 10.3390/genes15080991] [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: 06/16/2024] [Revised: 07/19/2024] [Accepted: 07/23/2024] [Indexed: 09/03/2024] Open
Abstract
Atypical porcine pestivirus (APPV) can cause congenital tremor type A-II in neonatal piglets, posing a significant threat to swine herd health globally. Our previous study demonstrated that the Mut domains, comprising 112 amino acids at the N-terminus, are the primary functional regions of the E2 protein of APPV. This study identified 14 host cellular proteins that exhibit potential interactions with the Mut domains of the E2 protein using yeast two-hybrid screening. Using bioinformatics analysis, we discovered that the Mut domains of the E2 protein might exert regulatory effects on apoptosis by modulating energy metabolism within the mitochondria. We also conducted co-immunoprecipitation, glutathione S-transferase pull-down, and immunofluorescence assays to confirm the interaction between the Mut domains of the E2 protein and cathepsin H and signal sequence receptor subunit 4 (SSR4). Ultimately, SSR4 enhanced APPV replication in vitro. In summary, our study successfully elucidated the interactions between the Mut domains of the E2 protein and host cell protein, predicted the potential pathways implicated in these interactions, and demonstrated SSR4 involvement in APPV infection. These significant findings contribute valuable knowledge toward a deeper understanding of APPV pathogenesis and the role of the Mut domains of the E2 protein in this intricate process.
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Affiliation(s)
- Yuai Yang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China; (Y.Y.); (G.J.); (W.H.); (X.T.); (B.X.)
| | - Guangfei Jiang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China; (Y.Y.); (G.J.); (W.H.); (X.T.); (B.X.)
| | - Weiqi He
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China; (Y.Y.); (G.J.); (W.H.); (X.T.); (B.X.)
| | - Xin Tian
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China; (Y.Y.); (G.J.); (W.H.); (X.T.); (B.X.)
| | - Huanli Zheng
- Yunnan Animal Health Supervision Institute, Kunming 650201, China;
| | - Bin Xiang
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China; (Y.Y.); (G.J.); (W.H.); (X.T.); (B.X.)
| | - Yongke Sun
- College of Veterinary Medicine, Yunnan Agricultural University, Kunming 650201, China; (Y.Y.); (G.J.); (W.H.); (X.T.); (B.X.)
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Han X, Xu H, Weng Y, Chen R, Xu J, Cao T, Sun R, Shan Y, He F, Fang W, Li X. N pro of classical swine fever virus enhances HMGB1 acetylation and its degradation by lysosomes to evade from HMGB1-mediated antiviral immunity. Virus Res 2024; 339:199280. [PMID: 37995963 PMCID: PMC10709370 DOI: 10.1016/j.virusres.2023.199280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 11/17/2023] [Accepted: 11/18/2023] [Indexed: 11/25/2023]
Abstract
Classical swine fever virus (CSFV) can dampen the host innate immunity by destabilizing IRF3 upon its binding with viral Npro. High mobility group box 1 (HMGB1), a non-histone nuclear protein, has diverse functions, including inflammation, innate immunity, etc., which are closely related to its cellular localization. We investigated potential mutual interactions between CSFV and HMGB1 and their effects on virus replication. We found that HMGB1 at the protein level, but not at mRNA level, was markedly reduced in CSFV-infected or Npro-expressing IPEC-J2 cells. HMGB1 in the nuclear compartment is anti-CSFV by promoting IFN-mediated innate immune response, as evidenced by overexpression of nuclear or cytoplasmic dominant HMGB1 mutant in IPEC-J2 cells stimulated with poly(I:C). However, CSFV Npro upregulates HMGB1 acetylation, a modification that promotes HMGB1 translocation into the cytoplasmic compartment where it is degraded by lysosomes. Ethyl pyruvate could downregulate HMGB1 acetylation and prevent Npro-mediated HMGB1 reduction. Inhibition of deacetylase HDAC1 with MS275 or by RNA silencing could promote Npro-mediated HMGB1 degradation. Taken together, our study elucidates the mechanism with which HMGB1 in the nuclei initiates antiviral innate immune response to suppress CSFV replication and elaborates the pathway by which CSFV uses its Npro to evade from HMGB1-mediated antiviral immunity through upregulating HMGB1 acetylation with subsequent translocation into cytoplasm for lysosomal degradation.
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Affiliation(s)
- Xiao Han
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Hankun Xu
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Yifan Weng
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Rong Chen
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Jidong Xu
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Tong Cao
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Renjie Sun
- Zhejiang Provincial Center for Animal Disease Prevention & Control, Hangzhou, Zhejiang 311199, China
| | - Ying Shan
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Fang He
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China
| | - Weihuan Fang
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China.
| | - Xiaoliang Li
- Zhejiang University Institute of Preventive Veterinary Medicine & Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, Hangzhou, Zhejiang 310058, China.
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Yang J, Yang B, Hao Y, Shi X, Yang X, Zhang D, Zhao D, Yan W, Chen L, Bie X, Chen G, Zhu Z, Li D, Shen C, Li G, Liu X, Zheng H, Zhang K. African swine fever virus MGF360-9L promotes viral replication by degrading the host protein HAX1. Virus Res 2023; 336:199198. [PMID: 37640268 PMCID: PMC10507221 DOI: 10.1016/j.virusres.2023.199198] [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: 05/07/2023] [Revised: 07/29/2023] [Accepted: 08/10/2023] [Indexed: 08/31/2023]
Abstract
African swine fever virus (ASFV) infection causes African swine fever (ASF), a virulent infectious disease that threatens the safety of livestock worldwide. Studies have shown that MGF360-9 L is important for the virulence of ASFV and the host protein HS1-associated protein X-1 (HAX1) plays an important role in viral pathogenesis. This study aimed to clarify the mechanism by which HAX1 mediates ASFV replication through interactions with MGF360-9 L. The regions of interaction between MGF360-9 L and HAX1 were predicted and validated. HAX1 overexpression and RNA interference studies revealed that HAX1 is a host restriction factor that suppresses ASFV replication. Moreover, HAX1 expression was inhibited in ASFV-infected mature bone marrow-derived macrophages, and infection with the virulent MGF360-9 L gene deletion strain (∆MGF360-9 L) attenuated the inhibitory effect of the wild-type strain (WT) on HAX1 expression, suggesting a complex regulatory relationship between MGF360-9 L and HAX1. Furthermore, the E3 ubiquitin ligase RNF114 interacted with MGF360-9 L and HAX1, MGF360-9 L degraded HAX1 through the ubiquitin-proteasome pathway, and RNF114 facilitated the degradation of HAX1 by MGF360-9L-linked K48 ubiquitin chains through the ubiquitin-proteasome pathway, thereby facilitating ASFV replication. In conclusion, this study has enriched our understanding of the regulatory networks between ASFV proteins and host proteins and provided a reference for investigation into the pathogenesis and immune escape mechanism of ASFV.
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Affiliation(s)
- Jinke Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Bo Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Yu Hao
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Xijuan Shi
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Xing Yang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Dajun Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Dengshuai Zhao
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Wenqian Yan
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Lingling Chen
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Xintian Bie
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Guohui Chen
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Zixiang Zhu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Dan Li
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Chaochao Shen
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Guoli Li
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Xiangtao Liu
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Haixue Zheng
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China
| | - Keshan Zhang
- State Key Laboratory for Animal Disease Control and Prevention, College of Veterinary Medicine, Lanzhou University, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou 730000, China.
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Wen S, Li X, Lv X, Liu K, Ren J, Zhai J, Song Y. Current progress on innate immune evasion mediated by Npro protein of pestiviruses. Front Immunol 2023; 14:1136051. [PMID: 37090696 PMCID: PMC10115221 DOI: 10.3389/fimmu.2023.1136051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 03/27/2023] [Indexed: 04/08/2023] Open
Abstract
Interferon (IFN), the most effective antiviral cytokine, is involved in innate and adaptive immune responses and is essential to the host defense against virus invasion. Once the host was infected by pathogens, the pathogen-associated molecular patterns (PAMPs) were recognized by the host pattern recognition receptors (PRRs), which activates interferon regulatory transcription factors (IRFs) and nuclear factor-kappa B (NF-κB) signal transduction pathway to induce IFN expression. Pathogens have acquired many strategies to escape the IFN-mediated antiviral immune response. Pestiviruses cause massive economic losses in the livestock industry worldwide every year. The immune escape strategies acquired by pestiviruses during evolution are among the major difficulties in its control. Previous experiments indicated that Erns, as an envelope glycoprotein unique to pestiviruses with RNase activity, could cleave viral ss- and dsRNAs, therefore inhibiting the host IFN production induced by viral ss- and dsRNAs. In contrast, Npro, the other envelope glycoprotein unique to pestiviruses, mainly stimulates the degradation of transcription factor IRF-3 to confront the IFN response. This review mainly summarized the current progress on mechanisms mediated by Npro of pestiviruses to antagonize IFN production.
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Affiliation(s)
- Shubo Wen
- Preventive Veterinary Laboratory, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
- Key Laboratory of Zoonose Prevention and Control, Universities of Inner Mongolia Autonomous Region, Tongliao, China
- Beef Cattle Disease Control and Engineering Technology Research Center, Inner Mongolia Autonomous Region, Tongliao, China
| | - Xintong Li
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Xiangyu Lv
- Preventive Veterinary Laboratory, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
- Beef Cattle Disease Control and Engineering Technology Research Center, Inner Mongolia Autonomous Region, Tongliao, China
| | - Kai Liu
- Preventive Veterinary Laboratory, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
- Beef Cattle Disease Control and Engineering Technology Research Center, Inner Mongolia Autonomous Region, Tongliao, China
| | - Jingqiang Ren
- Wenzhou Key Laboratory for Virology and Immunology, Institute of Virology, Wenzhou University, Zhejiang, Wenzhou, China
- *Correspondence: Jingqiang Ren, ; Jingbo Zhai, ; Yang Song,
| | - Jingbo Zhai
- Preventive Veterinary Laboratory, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
- Key Laboratory of Zoonose Prevention and Control, Universities of Inner Mongolia Autonomous Region, Tongliao, China
- *Correspondence: Jingqiang Ren, ; Jingbo Zhai, ; Yang Song,
| | - Yang Song
- Preventive Veterinary Laboratory, College of Animal Science and Technology, Inner Mongolia Minzu University, Tongliao, China
- Key Laboratory of Zoonose Prevention and Control, Universities of Inner Mongolia Autonomous Region, Tongliao, China
- *Correspondence: Jingqiang Ren, ; Jingbo Zhai, ; Yang Song,
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Zou X, Lin F, Yang Y, Chen J, Zhang H, Li L, Ouyang H, Pang D, Tang X. Cholesterol Biosynthesis Modulates CSFV Replication. Viruses 2022; 14:v14071450. [PMID: 35891429 PMCID: PMC9316236 DOI: 10.3390/v14071450] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/22/2022] [Accepted: 06/24/2022] [Indexed: 12/13/2022] Open
Abstract
Classical swine fever (CSF) caused by the classical swine fever virus (CSFV) has resulted in severe losses to the pig industry worldwide. It has been proposed that lipid synthesis is essential for viral replication, and lipids are involved in viral protein maturation and envelope production. However, the specific crosstalk between CSFV and host cell lipid metabolism is still unknown. In this study, we found that CSFV infection increased intracellular cholesterol levels in PK-15 cells. Further analysis demonstrated that CSFV infection upregulated PCSK9 expression to block the uptake of exogenous cholesterol by LDLR and enhanced the cholesterol biosynthesis pathway, which disrupted the type I IFN response in PK-15 cells. Our findings provide new insight into the mechanisms underpinning the pathogenesis of CSFV and hint at methods for controlling the disease.
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Affiliation(s)
- Xiaodong Zou
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
| | - Feng Lin
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
| | - Yang Yang
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
| | - Jiahuan Chen
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
| | - Huanyu Zhang
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
| | - Linquan Li
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
| | - Hongsheng Ouyang
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
- Chongqing Research Institute, Jilin University, Chongqing 401120, China
| | - Daxin Pang
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
- Chongqing Research Institute, Jilin University, Chongqing 401120, China
| | - Xiaochun Tang
- College of Animal Sciences, Jilin University, Changchun 130062, China; (X.Z.); (F.L.); (Y.Y.); (J.C.); (H.Z.); (L.L.); (H.O.); (D.P.)
- Chongqing Research Institute, Jilin University, Chongqing 401120, China
- Correspondence:
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Transcriptomic Analysis of MDBK Cells Infected with Cytopathic and Non-Cytopathic Strains of Bovine Viral Diarrhea Virus (BVDV). Viruses 2022; 14:v14061276. [PMID: 35746747 PMCID: PMC9228727 DOI: 10.3390/v14061276] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 02/04/2023] Open
Abstract
Bovine viral diarrhea virus (BVDV) belongs to the Flaviviridae family and the Pestivirus genus. Infection with BVDV causes a disease with a wide spectrum of clinical symptoms, most often mild, although infections with this virus constitute a serious economic problem all over the world. The virus is characterized by a high genetic variability, while the accumulation of single mutations leads to the formation of its new variants. The aim of this study was to better understand the complicated pathogenesis of this disease at the molecular level via the analysis of the transcriptome of cells infected with this virus. The bovine kidney cell line (MDBK), the cytopathic (cp) reference strain, and two non-cytopathic (ncp) BVD virus field strains were used in transcriptomic studies. The cell transcriptome was tested 24 and 72 h after infection. The results of the microarray analysis revealed changes in the expression levels of numerous genes. Genes with changed expression as a result of infection with the cp strain caused changes in the expression levels of a large number of genes and enriched a number of pathways. Genes with increased expression levels were enriched among other pathways involved in the cell cycle, while genes with reduced expression levels enriched pathways mostly related to metabolism. Genes with increased expression levels as a result of infection with ncp strains enriched a much smaller number of pathways, among them, pathways related to signaling activity 24 h post-infection and serine biosynthetic pathways both 24 and 72 h post-infection. Pathways enriched by genes with reduced expression levels were related to the innate immune response (72 h post-infection) or metabolism (24 and 72 h post-infection). The results of microarray studies can help us to better understand the host’s response to BVDV infection.
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A Human Endogenous Bornavirus-Like Nucleoprotein Encodes a Mitochondrial Protein Associated with Cell Viability. J Virol 2021; 95:e0203020. [PMID: 33952640 DOI: 10.1128/jvi.02030-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Endogenous retroviruses (ERVs) are sequences in animal genomes that originated from ancient retrovirus infections; they provide genetic novelty in hosts by being coopted as functional genes or elements during evolution. Recently, we demonstrated that endogenous elements from not only from retroviruses but also nonretroviral RNA viruses are a possible source of functional genes in host animals. The remnants of ancient bornavirus infections, called endogenous bornavirus-like elements (EBLs), are present in the genomes of a wide variety of vertebrate species, and some express functional products in host cells. Previous studies have predicted that the human EBL locus derived from bornavirus nucleoprotein, termed hsEBLN-2, expresses mRNA encoding a protein, suggesting that hsEBLN-2 has acquired a cellular function during evolution. However, the detailed function of the hsEBLN-2-derived product remains to be elucidated. In this study, we show that the hsEBLN-2-derived protein E2 acts as a mitochondrial protein that interacts with mitochondrial host factors associated with apoptosis, such as HAX-1. We also demonstrate that knockdown of hsEBLN-2-derived RNA increased the levels of PARP and caspase-3 cleavage and markedly decreased cell viability. In contrast, overexpression of E2 enhanced cell viability, as well as the intracellular stability of HAX-1, under stress conditions. Our results suggest that hsEBLN-2 has been coopted as a host gene, the product of which is involved in cell viability by interacting with mitochondrial proteins. IMPORTANCE Our genomes contain molecular fossils of ancient viruses, called endogenous virus elements (EVEs). Mounting evidence suggests that EVEs derived from nonretroviral RNA viruses have acquired functions in host cells during evolution. Previous studies have revealed that a locus encoding a bornavirus-derived EVE, hsEBLN-2, which was generated approximately 43 million years ago in a human ancestor, may be linked to the development of some tumors. However, the function of hsEBLN-2 has not been determined. In this study, we found that the E2 protein, an expression product of hsEBLN-2, interacts with apoptosis-related host proteins as a mitochondrial protein and affects cell viability. This study suggests that nonretroviral RNA viral EVEs have been coopted by hosts with more diverse functions than previously thought, showing a pivotal role for RNA virus infection in evolution.
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Ma SM, Mao Q, Yi L, Zhao MQ, Chen JD. Apoptosis, Autophagy, and Pyroptosis: Immune Escape Strategies for Persistent Infection and Pathogenesis of Classical Swine Fever Virus. Pathogens 2019; 8:pathogens8040239. [PMID: 31744077 PMCID: PMC6963731 DOI: 10.3390/pathogens8040239] [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: 10/16/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 01/21/2023] Open
Abstract
Classical swine fever (CSF) is a severe acute infectious disease that results from classical swine fever virus (CSFV) infection, which leads to serious economic losses in the porcine industry worldwide. In recent years, numerous studies related to the immune escape mechanism of the persistent infection and pathogenesis of CSFV have been performed. Remarkably, several independent groups have reported that apoptosis, autophagy, and pyroptosis play a significant role in the occurrence and development of CSF, as well as in the immunological process. Apoptosis, autophagy, and pyroptosis are the fundamental biological processes that maintain normal homeostatic and metabolic function in eukaryotic organisms. In general, these three cellular biological processes are always understood as an immune defense response initiated by the organism after perceiving a pathogen infection. Nevertheless, several viruses, including CSFV and other common pathogens such as hepatitis C and influenza A, have evolved strategies for infection and replication using these three cellular biological process mechanisms. In this review, we summarize the known roles of apoptosis, autophagy, and pyroptosis in CSFV infection and how viruses manipulate these three cellular biological processes to evade the immune response.
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Dong W, Lv H, Li C, Liu Y, Wang C, Lin J, Wang Y, Qian G, Guo K, Zhang Y. MAVS induces a host cell defense to inhibit CSFV infection. Arch Virol 2018; 163:1805-1821. [DOI: 10.1007/s00705-018-3804-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 02/13/2018] [Indexed: 01/09/2023]
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Lin J, Wang C, Liang W, Zhang J, Zhang L, Lv H, Dong W, Zhang Y. Rab1A is required for assembly of classical swine fever virus particle. Virology 2017; 514:18-29. [PMID: 29128753 DOI: 10.1016/j.virol.2017.11.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/28/2017] [Accepted: 11/02/2017] [Indexed: 12/20/2022]
Abstract
Rab1A belongs to the small Rab GTPase family and is involved in the lifecycle of numerous viruses. Here, knockdown of Rab1A inhibited CSFV growth. Further study revealed that Rab1A depletion decreased intracellular and extracellular CSFV titers, but did not affect intracellular virus genome copies and E2 protein expression within a virus lifecycle, which suggested that Rab1A is required for CSFV particle assembly rather than for genome replication or virion release. This was proofed by blocking the spread of virus using neutralizing antibodies, through which the negative effects of Rab1A knockdown on multi-cycle replication of CSFV were eliminated. Moreover, co-immunoprecipitation and confocal microscopy assays showed that Rab1A bound to CSFV NS5A protein, indicating that Rab1A and viral NS5A proteins may work cooperatively during CSFV particle assembly. In conclusion, this study demonstrated for the first time that Rab1A is required for CSFV particle assembly and binds to viral particle assembly-related NS5A protein.
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Affiliation(s)
- Jihui Lin
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Chengbao Wang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wulong Liang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China; College of Life Science, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Jing Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Longxiang Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Huifang Lv
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Wang Dong
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F University, Yangling, Shaanxi 712100, China.
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12
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Lin J, Wang C, Zhang L, Wang T, Zhang J, Liang W, Li C, Qian G, Ouyang Y, Guo K, Zhang Y. Rab5 Enhances Classical Swine Fever Virus Proliferation and Interacts with Viral NS4B Protein to Facilitate Formation of NS4B Related Complex. Front Microbiol 2017; 8:1468. [PMID: 28848503 PMCID: PMC5550665 DOI: 10.3389/fmicb.2017.01468] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/20/2017] [Indexed: 11/13/2022] Open
Abstract
Classical swine fever virus (CSFV) is a fatal pig pestivirus and causes serious financial losses to the pig industry. CSFV NS4B protein is one of the most important viral replicase proteins. Rab5, a member of the small Rab GTPase family, is involved in infection and replication of numerous viruses including hepatitis C virus and dengue virus. Until now, the effects of Rab5 on the proliferation of CSFV are poorly defined. In the present study, we showed that Rab5 could enhance CSFV proliferation by utilizing lentivirus-mediated constitutive overexpression and eukaryotic plasmid transient overexpression approaches. On the other hand, lentivirus-mediated short hairpin RNA knockdown of Rab5 dramatically inhibited virus production. Co-immunoprecipitation, glutathione S-transferase pulldown and laser confocal microscopy assays further confirmed the interaction between Rab5 and CSFV NS4B protein. In addition, intracellular distribution of NS4B-Red presented many granular fluorescent signals (GFS) in CSFV infected PK-15 cells. Inhibition of basal Rab5 function with Rab5 dominant negative mutant Rab5S34N resulted in disruption of the GFS. These results indicate that Rab5 plays a critical role in facilitating the formation of the NS4B related complexes. Furthermore, it was observed that NS4B co-localized with viral NS3 and NS5A proteins in the cytoplasm, suggesting that NS3 and NS5A might be components of the NS4B related complex. Taken together, these results demonstrate that Rab5 positively modulates CSFV propagation and interacts with NS4B protein to facilitate the NS4B related complexes formation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Yanming Zhang
- College of Veterinary Medicine, Northwest A&F UniversityYangling, China
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13
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Complex Virus-Host Interactions Involved in the Regulation of Classical Swine Fever Virus Replication: A Minireview. Viruses 2017; 9:v9070171. [PMID: 28678154 PMCID: PMC5537663 DOI: 10.3390/v9070171] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/15/2017] [Accepted: 06/27/2017] [Indexed: 02/06/2023] Open
Abstract
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is one of the most devastating epizootic diseases of pigs in many countries. Viruses are small intracellular parasites and thus rely on the cellular factors for replication. Fundamental aspects of CSFV-host interactions have been well described, such as factors contributing to viral attachment, modulation of genomic replication and translation, antagonism of innate immunity, and inhibition of cell apoptosis. However, those host factors that participate in the viral entry, assembly, and release largely remain to be elucidated. In this review, we summarize recent progress in the virus-host interactions involved in the life cycle of CSFV and analyze the potential mechanisms of viral entry, assembly, and release. We conclude with future perspectives and highlight areas that require further understanding.
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Wolkerstorfer S, Schwaiger E, Rinnerthaler M, Karina Gratz I, Zoegg T, Brandstetter H, Achatz-Straussberger G. HAX1 deletion impairs BCR internalization and leads to delayed BCR-mediated apoptosis. Cell Mol Immunol 2016; 13:451-61. [PMID: 25864916 PMCID: PMC4947813 DOI: 10.1038/cmi.2015.18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 02/11/2015] [Indexed: 12/25/2022] Open
Abstract
Deletion of HAX1 in mice causes a severe reduction in the numbers of lymphocytes in the bone marrow and in the spleen. Additionally, B220(+) B progenitor cells in the bone marrow are reduced, suggesting an important function of HAX1 in B cell development. HAX1 is thought to play a protective role in apoptotic processes; therefore, we investigated the role of HAX1 in bone marrow B progenitor cells and splenic B cells. We did not observe an effect on the survival of Hax1(-/-) bone marrow cells but detected enhanced survival of splenic Hax1(-/-) B cells upon in vitro starvation/growth-factor withdrawal. To explain this apparent inconsistency with previous reports of HAX1 function, we also studied the B cell receptor (BCR)-induced apoptosis of IgM-stimulated splenic naïve B cells and found that apoptosis decreased in these cells. We further found impaired internalization of the BCR from Hax1(-/-) splenic B cells after IgM crosslinking; this impaired internalization may result in decreased BCR signaling and, consequently, decreased BCR-mediated apoptosis. We measured HAX1 binding to the cytoplasmic domains of different Ig subtypes and identified KVKWI(V)F as the putative binding motif for HAX1 within the cytoplasmic domains. Because this motif can be found in almost all Ig subtypes, it is likely that HAX1 plays a general role in BCR-mediated internalization events and BCR-mediated apoptosis.
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Affiliation(s)
| | | | - Mark Rinnerthaler
- Department of Cell Biology, University of Salzburg, Salzburg, Austria
| | - Iris Karina Gratz
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
- Department of Dermatology, University of California San Francisco, CA, USA
- Department of Dermatology, Division of Molecular Dermatology and EB House Austria, Paracelsus Medical University, Salzburg, Austria
| | - Thomas Zoegg
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
| | - Hans Brandstetter
- Department of Molecular Biology, University of Salzburg, Salzburg, Austria
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Abstract
Pestiviruses are among the economically most important pathogens of livestock. The biology of these viruses is characterized by unique and interesting features that are both crucial for their success as pathogens and challenging from a scientific point of view. Elucidation of these features at the molecular level has made striking progress during recent years. The analyses revealed that major aspects of pestivirus biology show significant similarity to the biology of human hepatitis C virus (HCV). The detailed molecular analyses conducted for pestiviruses and HCV supported and complemented each other during the last three decades resulting in elucidation of the functions of viral proteins and RNA elements in replication and virus-host interaction. For pestiviruses, the analyses also helped to shed light on the molecular basis of persistent infection, a special strategy these viruses have evolved to be maintained within their host population. The results of these investigations are summarized in this chapter.
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Affiliation(s)
- Norbert Tautz
- Institute for Virology and Cell Biology, University of Lübeck, Lübeck, Germany
| | - Birke Andrea Tews
- Institut für Immunologie, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany
| | - Gregor Meyers
- Institut für Immunologie, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald-Insel Riems, Germany.
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16
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HAX1 deletion impairs BCR internalization and leads to delayed BCR-mediated apoptosis. Cell Mol Immunol 2015. [DOI: 10.1038/cmi.2015.018] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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17
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Yang Z, Shi Z, Guo H, Qu H, Zhang Y, Tu C. Annexin 2 is a host protein binding to classical swine fever virus E2 glycoprotein and promoting viral growth in PK-15 cells. Virus Res 2015; 201:16-23. [PMID: 25701745 DOI: 10.1016/j.virusres.2015.02.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 02/09/2015] [Accepted: 02/11/2015] [Indexed: 12/15/2022]
Abstract
Glycoprotein E2 of classical swine fever virus (CSFV) is a key determinant and major immunogen for viral entry and immunity, but little is known about its interaction with host proteins. In a previous study, we showed by proteomic analysis that cellular membrane protein annexin 2 (Anx2) was up-regulated in PK-15 cells following CSFV infection, but its function in CSFV replication remains unknown. In the present study we observed the interaction of Anx2 with CSFV E2 following infection of PK-15 cells by co-immunoprecipitation (Co-IP), mass spectrometry, Western blot and confocal laser scanning microscopy. The interaction between CSFV E2 and Anx2 was further confirmed in an E2-expressing PK-15 cell line, in which up-regulation of Anx2 was also observed, indicating that E2 alone can interact with, and increase, the expression of Anx2 protein. Further studies showed that siRNA-mediated knock-down and plasmid-mediated over-expression of Anx2 in PK-15 cells inhibited and increased CSFV replication and proliferation respectively. Remarkably, treatment of PK-15 cells with Anx2-specific polyclonal antibody prior to virus infection significantly inhibited CSFV multiplication, indicating that Anx2 is a cellular membrane protein likely associated with CSFV entry into cells. In conclusion, Anx2 is the novel host protein identified to interact with CSFV E2 and promote CSFV multiplication. These observations provide support for the potential use of Anx2 as a cellular target for the development of novel anti-CSFV therapies.
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Affiliation(s)
- Zhi Yang
- Veterinary College of Jilin University, Xi An Road 5333, Changchun 130062, China; Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary, Academy of Military Medical Sciences, Liuying West Road 666, Changchun 130122, China
| | - Zixue Shi
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary, Academy of Military Medical Sciences, Liuying West Road 666, Changchun 130122, China
| | - Huancheng Guo
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary, Academy of Military Medical Sciences, Liuying West Road 666, Changchun 130122, China
| | - Hui Qu
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary, Academy of Military Medical Sciences, Liuying West Road 666, Changchun 130122, China
| | - Yan Zhang
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary, Academy of Military Medical Sciences, Liuying West Road 666, Changchun 130122, China
| | - Changchun Tu
- Key Laboratory of Jilin Province for Zoonosis Prevention and Control, Institute of Military Veterinary, Academy of Military Medical Sciences, Liuying West Road 666, Changchun 130122, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
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18
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Ji W, Guo Z, Ding NZ, He CQ. Studying classical swine fever virus: Making the best of a bad virus. Virus Res 2015; 197:35-47. [DOI: 10.1016/j.virusres.2014.12.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 12/02/2014] [Accepted: 12/04/2014] [Indexed: 01/04/2023]
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19
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Screening of cellular proteins that interact with the classical swine fever virus non-structural protein 5A by yeast two-hybrid analysis. J Biosci 2014; 39:63-74. [PMID: 24499791 DOI: 10.1007/s12038-013-9411-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Classical swine fever virus (CSFV), the pathogen of classical swine fever (CSF), causes severe hemorrhagic fever and vascular necrosis in domestic pigs and wild boar. A large number of evidence has proven that non-structural 5A (NS5A) is not only a very important part of viral replication complex, but also can regulate host cell's function; however, the underlying mechanisms remain poorly understood. In the current study, aiming to find more clues in understanding the molecular mechanisms of CSFV NS5A's function, the yeast two-hybrid (Y2H) system was adopted to screen for CSFV NS5A interactive proteins in the cDNA library of the swine umbilical vein endothelial cell (SUVEC). Alignment with the NCBI database revealed 16 interactive proteins: DDX5, PSMC3, NAV1, PHF5A, GNB2L1, CSDE1, HSPA8, BRMS1, PPP2R3C, AIP, TMED10, POLR1C, TMEM70, METAP2, CHORDC1 and COPS6. These proteins are mostly related to gene transcription, protein folding, protein degradation and metabolism. The interactions detected by the Y2H system should be considered as preliminary results. Since identifying novel pathways and host targets, which play essential roles during infection, may provide potential targets for therapeutic development. The finding of proteins obtained from the SUVEC cDNA library that interact with the CSFV NS5A protein provide valuable information for better understanding the interactions between this viral protein and the host target proteins.
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20
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Jefferson M, Donaszi-Ivanov A, Pollen S, Dalmay T, Saalbach G, Powell PP. Host factors that interact with the pestivirus N-terminal protease, Npro, are components of the ribonucleoprotein complex. J Virol 2014; 88:10340-53. [PMID: 24965446 PMCID: PMC4178888 DOI: 10.1128/jvi.00984-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 06/18/2014] [Indexed: 12/22/2022] Open
Abstract
UNLABELLED The viral N-terminal protease N(pro) of pestiviruses counteracts cellular antiviral defenses through inhibition of IRF3. Here we used mass spectrometry to identify a new role for N(pro) through its interaction with over 55 associated proteins, mainly ribosomal proteins and ribonucleoproteins, including RNA helicase A (DHX9), Y-box binding protein (YBX1), DDX3, DDX5, eIF3, IGF2BP1, multiple myeloma tumor protein 2, interleukin enhancer binding factor 3 (IEBP3), guanine nucleotide binding protein 3, and polyadenylate-binding protein 1 (PABP-1). These are components of the translation machinery, ribonucleoprotein particles (RNPs), and stress granules. Significantly, we found that stress granule formation was inhibited in MDBK cells infected with a noncytopathic bovine viral diarrhea virus (BVDV) strain, Kyle. However, ribonucleoproteins binding to N(pro) did not inhibit these proteins from aggregating into stress granules. N(pro) interacted with YBX1 though its TRASH domain, since the mutant C112R protein with an inactive TRASH domain no longer redistributed to stress granules. Interestingly, RNA helicase A and La autoantigen relocated from a nuclear location to form cytoplasmic granules with N(pro). To address a proviral role for N(pro) in RNP granules, we investigated whether N(pro) affected RNA interference (RNAi), since interacting proteins are involved in RISC function during RNA silencing. Using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) silencing with small interfering RNAs (siRNAs) followed by Northern blotting of GAPDH, expression of N(pro) had no effect on RNAi silencing activity, contrasting with other viral suppressors of interferon. We propose that N(pro) is involved with virus RNA translation in the cytoplasm for virus particle production, and when translation is inhibited following stress, it redistributes to the replication complex. IMPORTANCE Although the pestivirus N-terminal protease, N(pro), has been shown to have an important role in degrading IRF3 to prevent apoptosis and interferon production during infection, the function of this unique viral protease in the pestivirus life cycle remains to be elucidated. We used proteomic mass spectrometry to identify novel interacting proteins and have shown that N(pro) is present in ribosomal and ribonucleoprotein particles (RNPs), indicating a translational role in virus particle production. The virus itself can prevent stress granule assembly from these complexes, but this inhibition is not due to N(pro). A proviral role to subvert RNA silencing through binding of these host RNP proteins was not identified for this viral suppressor of interferon.
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Affiliation(s)
- Matthew Jefferson
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Andras Donaszi-Ivanov
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
| | - Sean Pollen
- Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Tamas Dalmay
- Biological Sciences, University of East Anglia, Norwich, United Kingdom
| | - Gerhard Saalbach
- John Innes Centre, Norwich Research Park, Colney, Norwich, United Kingdom
| | - Penny P Powell
- Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich, Norfolk, United Kingdom
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21
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Hsu WL, Chen CL, Huang SW, Wu CC, Chen IH, Nadar M, Su YP, Tsai CH. The untranslated regions of classic swine fever virus RNA trigger apoptosis. PLoS One 2014; 9:e88863. [PMID: 24533157 PMCID: PMC3923050 DOI: 10.1371/journal.pone.0088863] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 01/13/2014] [Indexed: 11/23/2022] Open
Abstract
Classical swine fever virus (CSFV) causes a broad range of disease in pigs, from acute symptoms including high fever and hemorrhages, to chronic disease or unapparent infection, depending on the virus strain. CSFV belongs to the genus Pestivirus of the family Flaviviridae. It carries a single-stranded positive-sense RNA genome. An internal ribosomal entry site (IRES) in the 5' untranslated region (UTR) drives the translation of a single open reading frame encoding a 3898 amino acid long polypeptide chain. The open reading frame is followed by a 3' UTR comprising four highly structured stem-loops. In the present study, a synthetic RNA composed of the 5' and 3' UTRs of the CSFV genome devoid of any viral coding sequence and separated by a luciferase gene cassette (designated 5'UTR-Luc-3'UTR) triggered apoptotic cell death as early as 4 h post-transfection. The apoptosis was measured by DNA laddering analysis, TUNEL assay, annexin-V binding determined by flow cytometry, and by analysis of caspase activation. Contrasting with this, only trace DNA laddering was observed in cells transfected with the individual 5' or 3' UTR RNA; even when the 5' UTR and 3' UTR were co-transfected as separate RNA molecules, DNA laddering did not reach the level induced by the chimeric 5'UTR-Luc-3'UTR RNA. Interestingly, RNA composed of the 5'UTR and of stem-loop I of the 3'UTR triggered much stronger apoptosis than the 5' or 3'UTR alone. These results indicate that the 5' and 3' UTRs act together in cis induce apoptosis. We furthered obtained evidence that the UTR-mediated apoptosis required double-stranded RNA and involved translation shutoff possibly through activation of PKR.
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Affiliation(s)
- Wei-Li Hsu
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taichung, Taiwan
| | - Chung-Lun Chen
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Shi-Wei Huang
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Chia-Chen Wu
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taichung, Taiwan
| | - I-Hsuan Chen
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Muthukumar Nadar
- Department of Biotechnology, School of Biotechnology and Health Sciences, Karunya University, Coimbatore, Tamil Nadu, India
| | - Yin-Peng Su
- Graduate Institute of Microbiology and Public Health, National Chung Hsing University, Taichung, Taichung, Taiwan
| | - Ching-Hsiu Tsai
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
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22
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Gottipati K, Ruggli N, Gerber M, Tratschin JD, Benning M, Bellamy H, Choi KH. The structure of classical swine fever virus N(pro): a novel cysteine Autoprotease and zinc-binding protein involved in subversion of type I interferon induction. PLoS Pathog 2013; 9:e1003704. [PMID: 24146623 PMCID: PMC3798407 DOI: 10.1371/journal.ppat.1003704] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 08/24/2013] [Indexed: 12/17/2022] Open
Abstract
Pestiviruses express their genome as a single polypeptide that is subsequently cleaved into individual proteins by host- and virus-encoded proteases. The pestivirus N-terminal protease (Npro) is a cysteine autoprotease that cleaves between its own C-terminus and the N-terminus of the core protein. Due to its unique sequence and catalytic site, it forms its own cysteine protease family C53. After self-cleavage, Npro is no longer active as a protease. The released Npro suppresses the induction of the host's type-I interferon-α/β (IFN-α/β) response. Npro binds interferon regulatory factor-3 (IRF3), the key transcriptional activator of IFN-α/β genes, and promotes degradation of IRF3 by the proteasome, thus preventing induction of the IFN-α/β response to pestivirus infection. Here we report the crystal structures of pestivirus Npro. Npro is structurally distinct from other known cysteine proteases and has a novel “clam shell” fold consisting of a protease domain and a zinc-binding domain. The unique fold of Npro allows auto-catalysis at its C-terminus and subsequently conceals the cleavage site in the active site of the protease. Although many viruses interfere with type I IFN induction by targeting the IRF3 pathway, little information is available regarding structure or mechanism of action of viral proteins that interact with IRF3. The distribution of amino acids on the surface of Npro involved in targeting IRF3 for proteasomal degradation provides insight into the nature of Npro's interaction with IRF3. The structures thus establish the mechanism of auto-catalysis and subsequent auto-inhibition of trans-activity of Npro, and its role in subversion of host immune response. Mammalian cells respond to viral infection by inducing an innate immune response involving interferon-α/β that mediates cellular antiviral defenses. Viruses, in turn, have evolved mechanisms to counter the host's innate immune response by inhibiting the interferon response. Pestiviruses use the virally encoded N-terminal protease (Npro) to suppress interferon-α/β induction. Npro first cleaves itself off from the viral polyprotein using its own cysteine protease activity. Released Npro then interacts with interferon regulatory factor-3 (IRF3), a transcriptional activator of interferon-β, and induces proteasome-mediated degradation of IRF3. We have determined the crystal structure of Npro from classical swine fever virus. Npro has a unique protease fold consisting of two domains. The N-terminal domain carries the protease active site and has the C-terminus, the auto-cleavage site, bound in the active site. Thus, following auto-cleavage at the C-terminus, Npro obstructs the catalytic site preventing further activity, making the protease active only once in its lifetime. The C-terminal domain carries a zinc-binding site that is required for interaction with IRF3. Surface mapping of the Npro residues essential for subversion of interferon induction provides insight into the interaction with IRF3 and its subsequent degradation. To our knowledge, this is the first structure of a direct IRF3 antagonist.
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Affiliation(s)
- Keerthi Gottipati
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
| | - Nicolas Ruggli
- Institute of Virology and Immunology, Mittelhäusern, Switzerland
| | - Markus Gerber
- Institute of Virology and Immunology, Mittelhäusern, Switzerland
| | | | | | - Henry Bellamy
- Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, Louisiana, United States of America
| | - Kyung H. Choi
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, The University of Texas Medical Branch at Galveston, Galveston, Texas, United States of America
- * E-mail:
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Zögg T, Sponring M, Schindler S, Koll M, Schneider R, Brandstetter H, Auer B. Crystal structures of the viral protease Npro imply distinct roles for the catalytic water in catalysis. Structure 2013; 21:929-38. [PMID: 23643950 PMCID: PMC3677099 DOI: 10.1016/j.str.2013.04.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Revised: 03/22/2013] [Accepted: 04/01/2013] [Indexed: 11/30/2022]
Abstract
Npro is a key effector protein of pestiviruses such as bovine viral diarrhea virus and abolishes host cell antiviral defense mechanisms. Synthesized as the N-terminal part of the viral polyprotein, Npro releases itself via an autoproteolytic cleavage, triggering its immunological functions. However, the mechanisms of its proteolytic action and its immune escape were unclear. Here, we present the crystal structures of Npro to 1.25 Å resolution. Structures of pre- and postcleavage intermediates identify three catalytically relevant elements. The trapping of the putative catalytic water reveals its distinct roles as a base, acid, and nucleophile. The presentation of the substrate further explains the enigmatic latency of the protease, ensuring a single in cis cleavage. Additionally, we identified a zinc-free, disulfide-linked conformation of the TRASH motif, an interaction hub of immune factors. The structure opens additional opportunities in utilizing Npro as an autocleaving fusion protein and as a pharmaceutical target. Putative catalytic water reveals distinct roles as a base, acid, and nucleophile The structural mechanism explains a single in cis cleavage The bimodular architecture reflects proteolytic and immunological functions The structure provides two orthogonal targets for therapy
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Affiliation(s)
- Thomas Zögg
- Department of Molecular Biology, University of Salzburg, Billrothstraße 11, 5020 Salzburg, Austria
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24
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Down-regulation of cellular protein heme oxygenase 1 inhibits proliferation of classical swine fever virus in PK-15 cells. Virus Res 2013; 173:315-20. [DOI: 10.1016/j.virusres.2013.01.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 01/15/2013] [Accepted: 01/16/2013] [Indexed: 01/22/2023]
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25
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Boztug K, Klein C. Genetics and Pathophysiology of Severe Congenital Neutropenia Syndromes Unrelated to Neutrophil Elastase. Hematol Oncol Clin North Am 2013; 27:43-60, vii. [DOI: 10.1016/j.hoc.2012.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Peterhans E, Schweizer M. BVDV: A pestivirus inducing tolerance of the innate immune response. Biologicals 2013; 41:39-51. [DOI: 10.1016/j.biologicals.2012.07.006] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 07/16/2012] [Indexed: 12/14/2022] Open
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Poly(C)-binding protein 1, a novel N(pro)-interacting protein involved in classical swine fever virus growth. J Virol 2012; 87:2072-80. [PMID: 23221550 DOI: 10.1128/jvi.02807-12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
N(pro) is a multifunctional autoprotease unique to pestiviruses. The interacting partners of the N(pro) protein of classical swine fever virus (CSFV), a swine pestivirus, have been insufficiently defined. Using a yeast two-hybrid screen, we identified poly(C)-binding protein 1 (PCBP1) as a novel interacting partner of the CSFV N(pro) protein and confirmed this by coimmunoprecipitation, glutathione S-transferase (GST) pulldown, and confocal assays. Knockdown of PCBP1 by small interfering RNA suppressed CSFV growth, while overexpression of PCBP1 promoted CSFV growth. Furthermore, we showed that type I interferon was downregulated by PCBP1, as well as N(pro). Our results suggest that cellular PCBP1 positively modulates CSFV growth.
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Klein C. Genetic defects in severe congenital neutropenia: emerging insights into life and death of human neutrophil granulocytes. Annu Rev Immunol 2011; 29:399-413. [PMID: 21219176 DOI: 10.1146/annurev-immunol-030409-101259] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The discovery of genetic defects causing congenital neutropenia has illuminated mechanisms controlling differentiation, circulation, and decay of neutrophil granulocytes. Deficiency of the mitochondrial proteins HAX1 and AK2 cause premature apoptosis of myeloid progenitor cells associated with dissipation of the mitochondrial membrane potential, whereas mutations in ELA2/ELANE and G6PC3 are associated with signs of increased endoplasmic reticulum stress. Mutations in the transcriptional repressor GFI1 and the cytoskeletal regulator WASP also lead to defective neutrophil production. This unexpected diversity of factors suggests that multiple pathways are involved in the pathogenesis of congenital neutropenia.
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Affiliation(s)
- Christoph Klein
- Department of Pediatric Hematology/Oncology, Hannover Medical School, Germany.
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