1
|
Chen Z, Zhang J, Feng T, Wang X, Zhou S, Pan W, Chen Z, Yan Y, Dai J. DDX20 positively regulates the interferon pathway to inhibit viral infection. Antiviral Res 2024; 225:105875. [PMID: 38552910 DOI: 10.1016/j.antiviral.2024.105875] [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: 12/18/2023] [Revised: 03/23/2024] [Accepted: 03/26/2024] [Indexed: 04/04/2024]
Abstract
The DEAD-box (DDX) family comprises RNA helicases characterized by the conserved sequence D(Asp)-E(Glu)-A(Ala)-D(Asp), participating in various RNA metabolism processes. Some DDX family members have been identified for their crucial roles in viral infections. In this study, RNAi library screening of the DDX family unveiled the antiviral activity of DDX20. Knockdown of DDX20 enhanced the replication of viruses such as vesicular stomatitis virus (VSV) and herpes simplex virus type I (HSV-1), while overexpression of DDX20 significantly diminished the replication level of these viruses. Mechanistically, DDX20 elevated the phosphorylation level of IRF3 induced by external stimuli by facilitating the interaction between TBK1 and IRF3, thereby promoting the expression of IFN-β. The increased IFN-β production, in turn, upregulated the expression of interferon-stimulated genes (ISGs), including Cig5 and IFIT1, thereby exerting the antiviral effect. Finally, in an in vivo infection study, Ddx20 gene-deficient mice exhibited increased susceptibility to viral infection. This study provides new evidence that DDX20 positively modulates the interferon pathway and restricts viral infection.
Collapse
Affiliation(s)
- Zhiqiang Chen
- Department of Nuclear Medicine, The First Affiliated Hospital of Soochow University, Suzhou, China; Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China.
| | - Jinyu Zhang
- Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China.
| | - Tingting Feng
- Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China; Central Laboratory, The Fourth Affiliated Hospital of Nanjing Medical University, Nanjing, China.
| | - Xiujuan Wang
- Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China.
| | - Shimeng Zhou
- Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China.
| | - Wen Pan
- Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China.
| | - Zhengrong Chen
- Department of Respiratory Medicine, Children's Hospital of Soochow University, Suzhou, China.
| | - Yongdong Yan
- Department of Respiratory Medicine, Children's Hospital of Soochow University, Suzhou, China.
| | - Jianfeng Dai
- Institute of Biology and Medical Sciences, MOE Key Laboratory of Geriatric Diseases and Immunology, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, China.
| |
Collapse
|
2
|
Olenginski LT, Attionu SK, Henninger EN, LeBlanc RM, Longhini AP, Dayie TK. Hepatitis B Virus Epsilon (ε) RNA Element: Dynamic Regulator of Viral Replication and Attractive Therapeutic Target. Viruses 2023; 15:1913. [PMID: 37766319 PMCID: PMC10534774 DOI: 10.3390/v15091913] [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: 07/01/2023] [Revised: 09/01/2023] [Accepted: 09/05/2023] [Indexed: 09/29/2023] Open
Abstract
Hepatitis B virus (HBV) chronically infects millions of people worldwide, which underscores the importance of discovering and designing novel anti-HBV therapeutics to complement current treatment strategies. An underexploited but attractive therapeutic target is ε, a cis-acting regulatory stem-loop RNA situated within the HBV pregenomic RNA (pgRNA). The binding of ε to the viral polymerase protein (P) is pivotal, as it triggers the packaging of pgRNA and P, as well as the reverse transcription of the viral genome. Consequently, small molecules capable of disrupting this interaction hold the potential to inhibit the early stages of HBV replication. The rational design of such ligands necessitates high-resolution structural information for the ε-P complex or its individual components. While these data are currently unavailable for P, our recent structural elucidation of ε through solution nuclear magnetic resonance spectroscopy marks a significant advancement in this area. In this review, we provide a brief overview of HBV replication and some of the therapeutic strategies to combat chronic HBV infection. These descriptions are intended to contextualize our recent experimental efforts to characterize ε and identify ε-targeting ligands, with the ultimate goal of developing novel anti-HBV therapeutics.
Collapse
Affiliation(s)
- Lukasz T. Olenginski
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA (R.M.L.)
- Department of Biochemistry, University of Colorado, Boulder, CO 80309, USA
| | - Solomon K. Attionu
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA (R.M.L.)
| | - Erica N. Henninger
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA (R.M.L.)
| | - Regan M. LeBlanc
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA (R.M.L.)
| | - Andrew P. Longhini
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA (R.M.L.)
- Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - Theodore K. Dayie
- Center for Biomolecular Structure and Organization, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA (R.M.L.)
| |
Collapse
|
3
|
Bonaventure B, Goujon C. DExH/D-box helicases at the frontline of intrinsic and innate immunity against viral infections. J Gen Virol 2022; 103. [PMID: 36006669 DOI: 10.1099/jgv.0.001766] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022] Open
Abstract
DExH/D-box helicases are essential nucleic acid and ribonucleoprotein remodelers involved in all aspects of nucleic acid metabolism including replication, gene expression and post-transcriptional modifications. In parallel to their importance in basic cellular functions, DExH/D-box helicases play multiple roles in viral life cycles, with some of them highjacked by viruses or negatively regulating innate immune activation. However, other DExH/D-box helicases have recurrently been highlighted as direct antiviral effectors or as positive regulators of innate immune activation. Innate immunity relies on the ability of Pathogen Recognition Receptors to recognize viral signatures and trigger the production of interferons (IFNs) and pro-inflammatory cytokines. Secreted IFNs interact with their receptors to establish antiviral cellular reprogramming via expression regulation of the interferon-stimulated genes (ISGs). Several DExH/D-box helicases have been reported to act as viral sensors (DDX3, DDX41, DHX9, DDX1/DDX21/DHX36 complex), and others to play roles in innate immune activation (DDX60, DDX60L, DDX23). In contrast, the DDX39A, DDX46, DDX5 and DDX24 helicases act as negative regulators and impede IFN production upon viral infection. Beyond their role in viral sensing, the ISGs DDX60 and DDX60L act as viral inhibitors. Interestingly, the constitutively expressed DEAD-box helicases DDX56, DDX17, DDX42 intrinsically restrict viral replication. Hence, DExH/D-box helicases appear to form a multilayer network of primary and secondary factors involved in both intrinsic and innate antiviral immunity. In this review, we highlight recent findings on the extent of antiviral defences played by helicases and emphasize the need to better understand their immune functions as well as their complex interplay.
Collapse
Affiliation(s)
- Boris Bonaventure
- IRIM, CNRS, Montpellier University, France.,Present address: Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | |
Collapse
|
4
|
Rao S, Mahmoudi T. DEAD-ly Affairs: The Roles of DEAD-Box Proteins on HIV-1 Viral RNA Metabolism. Front Cell Dev Biol 2022; 10:917599. [PMID: 35769258 PMCID: PMC9234453 DOI: 10.3389/fcell.2022.917599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/23/2022] [Indexed: 11/13/2022] Open
Abstract
In order to ensure viral gene expression, Human Immunodeficiency virus type-1 (HIV-1) recruits numerous host proteins that promote optimal RNA metabolism of the HIV-1 viral RNAs (vRNAs), such as the proteins of the DEAD-box family. The DEAD-box family of RNA helicases regulates multiple steps of RNA metabolism and processing, including transcription, splicing, nucleocytoplasmic export, trafficking, translation and turnover, mediated by their ATP-dependent RNA unwinding ability. In this review, we provide an overview of the functions and role of all DEAD-box family protein members thus far described to influence various aspects of HIV-1 vRNA metabolism. We describe the molecular mechanisms by which HIV-1 hijacks these host proteins to promote its gene expression and we discuss the implications of these interactions during viral infection, their possible roles in the maintenance of viral latency and in inducing cell death. We also speculate on the emerging potential of pharmacological inhibitors of DEAD-box proteins as novel therapeutics to control the HIV-1 pandemic.
Collapse
Affiliation(s)
- Shringar Rao
- Department of Biochemistry, Erasmus University Medical Centre, Rotterdam, Netherlands
- *Correspondence: Shringar Rao, ; Tokameh Mahmoudi,
| | - Tokameh Mahmoudi
- Department of Biochemistry, Erasmus University Medical Centre, Rotterdam, Netherlands
- Department of Pathology, Erasmus University Medical Centre, Rotterdam, Netherlands
- Department of Urology, Erasmus University Medical Centre, Rotterdam, Netherlands
- *Correspondence: Shringar Rao, ; Tokameh Mahmoudi,
| |
Collapse
|
5
|
Xu S, Xie J, Zhang X, Chen L, Bi Y, Li X, Idris A, Feng R. DDX56 antagonizes IFN-β production to enhance EMCV replication by inhibiting IRF3 nuclear translocation. Vet Microbiol 2021; 264:109304. [PMID: 34922148 DOI: 10.1016/j.vetmic.2021.109304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/07/2021] [Accepted: 12/11/2021] [Indexed: 12/23/2022]
Abstract
DEAD (Asp-Glu-Ala-Asp)-box RNA helicases (DDX) play important roles in viral infection, either as cytosolic viral nucleic acids sensors or as essential host factors for viral replication. In this study, we identified DDX56 as a positive regulator for encephalomyocarditis virus (EMCV) replication. EMCV infection promotes DDX56 expression via its viral proteins, VP3 and 3C. We showed that DDX56 overexpression promotes EMCV replication whereas its loss dampened EMCV replication. Consequently, knockdown of DDX56 increases type I interferon (IFN) expression during EMCV infection. We also showed that DDX56 interrupts IFN regulatory factor 3 (IRF3) phosphorylation and its nucleus translocation by directly targeting KPNA3 and KPNA4 in an EMCV-triggered MDA5 signaling activation cascade leading to the blockade of IFN-β production. Overall, we showed that DDX56 is a novel negative regulator of EMCV-mediated IFN-β responses and that DDX56 plays a critical role in EMCV replication. These findings reveal a novel strategy for EMCV to utilize a host factor to evade the host innate immune response and provide us new insight into the function of DDX56.
Collapse
Affiliation(s)
- Shujuan Xu
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Jingying Xie
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Xiangbo Zhang
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Lei Chen
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Yingjie Bi
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Xiangrong Li
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China
| | - Adi Idris
- Menzies Health Institute Queensland, School of Pharmacy and Medical Science, Griffith University, Southport, Queensland, Australia
| | - Ruofei Feng
- Key Laboratory of Biotechnology and Bioengineering of State Ethnic Affairs Commission, Biomedical Research Center, Northwest Minzu University, Lanzhou, China; Gansu Tech Innovation Center of Animal Cell, Biomedical Research Center, Northwest Minzu University, Lanzhou, China.
| |
Collapse
|
6
|
DEAD/H-box helicases:Anti-viral and pro-viral roles during infections. Virus Res 2021; 309:198658. [PMID: 34929216 DOI: 10.1016/j.virusres.2021.198658] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/26/2021] [Accepted: 12/14/2021] [Indexed: 02/08/2023]
Abstract
DEAD/H-box RNA helicases make the prominent family of helicases super family-2 which take part in almost all RNA-related processes, from initiation of transcription to RNA decay pathways. In addition to these RNA-related activities, in recent years a certain number of these helicases are reported to play important roles in anti-viral immunity through various ways. Along with RLHs, endosomal TLRs, and cytosolic DNA receptors, many RNA helicases including DDX3, DHX9, DDX6, DDX41, DHX33, DDX60, DHX36 and DDX1-DDX21-DHX36 complex act as viral nucleic acid sensors or co-sensors. These helicases mostly follow RLHs-MAVS and STING mediated signaling cascades to trigger induction of type-I interferons and pro-inflammatory cytokines. Many of them also function as downstream adaptor molecules (DDX3), segments of stress and processing bodies (DDX3 and DDX6) or negative regulators (DDX19, DDX24, DDX25, DDX39A and DDX46). On the contrary, many studies indicated that several DEAD/H-box helicases such as DDX1, DDX3, DDX6, DDX24, and DHX9 could be exploited by viruses to evade innate immune responses, suggesting that these helicases seem to have a dual function as anti-viral innate immune mediators and viral replication cofactors. In this review, we summarized the current knowledge on several representative DEAD/H-box helicases, with an emphasis on their functions in innate immunity responses, involved in their anti-viral and pro-viral roles.
Collapse
|
7
|
Su C, Tang YD, Zheng C. DExD/H-box helicases: multifunctional regulators in antiviral innate immunity. Cell Mol Life Sci 2021; 79:2. [PMID: 34910251 PMCID: PMC8671602 DOI: 10.1007/s00018-021-04072-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/29/2021] [Accepted: 12/01/2021] [Indexed: 02/07/2023]
Abstract
DExD/H-box helicases play critical roles in multiple cellular processes, including transcription, cellular RNA metabolism, translation, and infections. Several seminal studies over the past decades have delineated the distinct functions of DExD/H-box helicases in regulating antiviral innate immune signaling pathways, including Toll-like receptors, retinoic acid-inducible gene I-like receptors, cyclic GMP-AMP synthase-the stimulator of interferon gene, and NOD-like receptors signaling pathways. Besides the prominent regulatory roles, there is increasing attention on their functions as nucleic acid sensors involved in antiviral innate immunity. Here we summarize the complex regulatory roles of DExD/H-box helicases in antiviral innate immunity. A better understanding of the underlying molecular mechanisms of DExD/H-box helicases' regulatory roles is vital for developing new therapeutics targeting DExD/H-box helicases and their mediated signaling transduction in viral infectious diseases.
Collapse
Affiliation(s)
- Chenhe Su
- Department of Immunology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China
- The Wistar Institute, Philadelphia, PA, USA
| | - Yan-Dong Tang
- State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China
| | - Chunfu Zheng
- Department of Immunology, School of Basic Medical Sciences, Fujian Medical University, Fuzhou, China.
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada.
| |
Collapse
|
8
|
Zhang R, Cheng M, Liu B, Yuan M, Chen D, Wang Y, Wu Z. DEAD-Box Helicase DDX6 Facilitated RIG-I-Mediated Type-I Interferon Response to EV71 Infection. Front Cell Infect Microbiol 2021; 11:725392. [PMID: 34485180 PMCID: PMC8414799 DOI: 10.3389/fcimb.2021.725392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 07/28/2021] [Indexed: 12/24/2022] Open
Abstract
Previous studies have shown that DEAD (Glu-Asp-Ala-Glu)-box RNA helicases play important roles in viral infection, either as cytosolic sensors of pathogenic molecules or as essential host factors against viral infection. In the current study, we found that DDX6, an RNA helicase belonging to the DEAD-box family of helicase, exhibited anti-Enterovirus 71 activity through augmenting RIG-I-mediated type-I IFN response. Moreover, DDX6 binds viral RNA to form an RNA-protein complex to positively regulate the RIG-I-mediated interferon response; however, EV71 has evolved a strategy to antagonize the antiviral effect of DDX6 by proteolytic degradation of the molecule through its non-structural protein 2A, a virus-encoded protease.
Collapse
Affiliation(s)
- Rui Zhang
- Center for Public Health Research, Medical School, Nanjing University, Nanjing, China
| | - Min Cheng
- Center for Public Health Research, Medical School, Nanjing University, Nanjing, China
| | - Bingxin Liu
- Center for Public Health Research, Medical School, Nanjing University, Nanjing, China
| | - Meng Yuan
- Center for Public Health Research, Medical School, Nanjing University, Nanjing, China
| | - Deyan Chen
- Center for Public Health Research, Medical School, Nanjing University, Nanjing, China
| | - Yujiong Wang
- School of Life Sciences, Ningxia University, Yinchuan, China
| | - Zhiwei Wu
- Center for Public Health Research, Medical School, Nanjing University, Nanjing, China
- School of Life Sciences, Ningxia University, Yinchuan, China
- Medical School and Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, China
- State Key Lab of Analytical Chemistry for Life Science, Nanjing University, Nanjing, China
| |
Collapse
|
9
|
Takaoka A, Yamada T. Regulation of signaling mediated by nucleic acid sensors for innate interferon-mediated responses during viral infection. Int Immunol 2019; 31:477-488. [PMID: 30985869 PMCID: PMC7110195 DOI: 10.1093/intimm/dxz034] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 04/12/2019] [Indexed: 12/17/2022] Open
Abstract
Type I and type III interferons are important anti-viral cytokines that are massively induced during viral infection. This dynamic process is regulated by many executors and regulators for efficient eradication of invading viruses and protection from harmful, excessive responses. An array of innate sensors recognizes virus-derived nucleic acids to activate their downstream signaling to evoke cytokine responses including interferons. In particular, a cytoplasmic RNA sensor RIG-I (retinoic acid-inducible gene I) is involved in the detection of multiple types of not only RNA viruses but also DNA viruses. Accumulating findings have revealed that activation of nucleic acid sensors and the related signaling mediators is regulated on the basis of post-translational modification such as ubiquitination, phosphorylation and ADP-ribosylation. In addition, long non-coding RNAs (lncRNAs) have been implicated as a new class of regulators in innate signaling. A comprehensive understanding of the regulatory mechanisms of innate sensor activation and its signaling in host-virus interaction will provide a better therapeutic strategy to efficiently control viral infection and maintain immune homeostasis.
Collapse
Affiliation(s)
- Akinori Takaoka
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
- Correspondence to: A. Takaoka; E-mail:
| | - Taisho Yamada
- Division of Signaling in Cancer and Immunology, Institute for Genetic Medicine, Hokkaido University, Sapporo, Hokkaido, Japan
| |
Collapse
|
10
|
Zou C, Huang C, Zhang J, Wu Q, Ni X, Sun J, Dai J. Virulence difference of five type I dengue viruses and the intrinsic molecular mechanism. PLoS Negl Trop Dis 2019; 13:e0007202. [PMID: 30830907 PMCID: PMC6417740 DOI: 10.1371/journal.pntd.0007202] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 03/14/2019] [Accepted: 01/30/2019] [Indexed: 12/23/2022] Open
Abstract
Dengue virus (DENV) is the most important vector-borne virus globally. The safe and effective vaccines are still under development and there are no antiviral drugs for DENV induced diseases. In this study, we obtained five DENV1 isolates (DENV1 A to E) from the outbreak of dengue fever in 2014 of Guangzhou, China, and analyzed their replication efficiency and virulence in vitro and in vivo. The results suggested that among the five DENV1 strains, DENV1 B has the highest replication efficiency in both human and mosquito cells in vitro, also causes the highest mortality to suckling mice. Further study suggested that nonstructural proteins from DENV1B have higher capacity to suppress host interferon signaling. In addition, the NS2B3 protease from DENV1B has higher enzymatic activity compared with that from DENV1 E. Finally, we identified that the 64th amino acid of NS2A and the 55th amino acid of NS2B were two virulence determining sites for DENV1. This study provided new evidences of the molecular mechanisms of DENV virulence. Dengue is the most important vector-borne viral infection that endangers an estimated 2.5 billion people globally. The recently licensed dengue vaccine has major weaknesses and there are no antiviral drugs for the treatment of dengue related diseases. Identifying the virulence determinants is important for understanding the molecule bases of viral life cycle, also contributing to vaccine design and development. In this study, we analyzed the virulence differences among five DENV1 strains that obtained from the 2014 DENV outbreak in Guangzhou, China, and identified two novel virulence determining sites for DENV1. This study provides new ideas for investigation of DENV protein function, pathogenic mechanism and novel attenuated vaccine.
Collapse
Affiliation(s)
- Chunling Zou
- Institutes of Biology and Medical Sciences, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, P. R. China
| | - Chenxiao Huang
- Institutes of Biology and Medical Sciences, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, P. R. China
| | - Jinyu Zhang
- Institutes of Biology and Medical Sciences, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, P. R. China
| | - Qihan Wu
- NHC Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Fudan University, Shanghai, P.R. China
| | - Xiaohua Ni
- NHC Key Lab of Reproduction Regulation (Shanghai Institute of Planned Parenthood Research), Fudan University, Shanghai, P.R. China
- * E-mail: (XN) ; (JS) ; (JD)
| | - Jiufeng Sun
- Guangdong Provincial Institute of Public Health, Guangdong Provincial Center for Disease Control and Prevention, Guangzhou, P.R. China
- * E-mail: (XN) ; (JS) ; (JD)
| | - Jianfeng Dai
- Institutes of Biology and Medical Sciences, Jiangsu Key Laboratory of Infection and Immunity, Soochow University, Suzhou, P. R. China
- * E-mail: (XN) ; (JS) ; (JD)
| |
Collapse
|
11
|
Perčulija V, Ouyang S. Diverse Roles of DEAD/DEAH-Box Helicases in Innate Immunity and Diseases. HELICASES FROM ALL DOMAINS OF LIFE 2019. [PMCID: PMC7158350 DOI: 10.1016/b978-0-12-814685-9.00009-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
DEAD/DEAH-box helicases are enzymes that belong to the DEAD/H-box family of SF2 helicase superfamily. These enzymes are essential in RNA metabolism, where they are involved in a number of processes that require manipulation of RNA structure. Recent studies have found that some DEAD/DEAH-box helicases play important roles in innate immunity, where they act as sensors of cytosolic DNA/RNA, as adaptor proteins, or as regulators of signaling and gene expression. In spite of their function in immunity, DEAD/DEAH-box helicases can also be hijacked and exploited by viruses to circumvent detection and aid in viral replication. These findings not only imply that DEAD/DEAH-box helicases have a broader function than previously thought, but also give us a much better understanding of immune mechanisms and diseases that arise due to the dysregulation or evasion thereof. In this chapter, we demonstrate the known scope of activities of human DEAD/DEAH-box helicases in innate immunity and interaction with viruses or other pathogens. Additionally, we give an outline of diseases in which they are, or may be, involved in the context of immunity.
Collapse
|
12
|
Núñez RD, Budt M, Saenger S, Paki K, Arnold U, Sadewasser A, Wolff T. The RNA Helicase DDX6 Associates with RIG-I to Augment Induction of Antiviral Signaling. Int J Mol Sci 2018; 19:E1877. [PMID: 29949917 PMCID: PMC6073104 DOI: 10.3390/ijms19071877] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Revised: 04/13/2018] [Accepted: 06/22/2018] [Indexed: 12/25/2022] Open
Abstract
Virus infections induce sensitive antiviral responses within the host cell. The RNA helicase retinoic acid-inducible gene I (RIG-I) is a key sensor of influenza virus RNA that induces the expression of antiviral type I interferons. Recent evidence suggests a complex pattern of RIG-I regulation involving multiple interactions and cellular sites. In an approach employing affinity purification and quantitative mass spectrometry, we identified proteins with increased binding to RIG-I in response to influenza B virus infection. Among them was the RIG-I related RNA helicase DEAD box helicase 6 (DDX6), a known component of cytoplasmic mRNA-ribonucleoprotein (mRNP) granules like P-bodies and stress granules (SGs). RIG-I and DDX6 both localized to the cytosol and were detected in virus-induced SGs. Coimmunoprecipitation assays detected a basal level of complexes harboring RIG-I and DDX6 that increased after infection. Functionally, DDX6 augmented RIG-I mediated induction of interferon (IFN)-β expression. Notably, DDX6 was found to bind viral RNA capable to stimulate RIG-I. These findings imply a novel function for DDX6 as an RNA co-sensor and signaling enhancer for RIG-I.
Collapse
Affiliation(s)
- Rocío Daviña Núñez
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| | - Matthias Budt
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| | - Sandra Saenger
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| | - Katharina Paki
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| | - Ulrike Arnold
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| | - Anne Sadewasser
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| | - Thorsten Wolff
- Robert Koch-Institut, FG17-Division of Influenza Viruses and other Respiratory Viruses, 13353 Berlin, Germany.
| |
Collapse
|