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Wu Z, Zhang C, Huang Y, Tao N, Wang T, Cai X, Wang Z, Li X. Tryptanthrin Derivative B1 Binds Viral Genome-Linked Protein (VPg) of Potato Virus Y. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:5699-5709. [PMID: 38462724 DOI: 10.1021/acs.jafc.4c01306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Potato virus Y (PVY) is a plant virus that is known to be responsible for substantial economic losses in agriculture. Within the PVY genome, viral genome-linked protein (VPg) plays a pivotal role in the viral translation process. In this study, VPg was used as a potential target for analyzing the antiviral activity of tryptanthrin derivatives. In vitro, the dissociation constants of B1 with PVY VPg were 0.69 μmol/L (measured by microscale thermophoresis) and 4.01 μmol/L (measured via isothermal titration calorimetry). B1 also strongly bound to VPg proteins from three other Potyviruses. Moreover, in vivo experiments demonstrated that B1 effectively suppressed the expression of the PVY gene. Molecular docking experiments revealed that B1 formed a hydrogen bond with N121 and that no specific binding occurred between B1 and the PVY VPgN121A mutant. Therefore, N121 is a key amino acid residue in PVY VPg involved in B1 binding. These results highlight the potential of PVY VPg as a potential target for the development of antiviral agents.
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Affiliation(s)
- Zilin Wu
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Chun Zhang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Yuanqin Huang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Na Tao
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Tao Wang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Xiaobo Cai
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
| | - Zhenchao Wang
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
- College of Pharmacy, Guizhou University, Guiyang 550025, China
| | - Xiangyang Li
- National Key Laboratory of Green Pesticide, Key Laboratory of Green Pesticide and Agricultural Bioengineering, Ministry of Education, Guizhou University, Huaxi District, Guiyang 550025, China
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Dixit K, Karanth NM, Nair S, Kumari K, Chakrabarti KS, Savithri HS, Sarma SP. Aromatic Interactions Drive the Coupled Folding and Binding of the Intrinsically Disordered Sesbania mosaic Virus VPg Protein. Biochemistry 2020; 59:4663-4680. [PMID: 33269926 DOI: 10.1021/acs.biochem.0c00721] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The plant Sesbania mosaic virus [a (+)-ssRNA sobemovirus] VPg protein is intrinsically disordered in solution. For the virus life cycle, the VPg protein is essential for replication and for polyprotein processing that is carried out by a virus-encoded protease. The nuclear magnetic resonance (NMR)-derived tertiary structure of the protease-bound VPg shows it to have a novel tertiary structure with an α-β-β-β topology. The quaternary structure of the high-affinity protease-VPg complex (≈27 kDa) has been determined using HADDOCK protocols with NMR (residual dipolar coupling, dihedral angle, and nuclear Overhauser enhancement) restraints and mutagenesis data as inputs. The geometry of the complex is in excellent agreement with long-range orientational restraints such as residual dipolar couplings and ring-current shifts. A "vein" of aromatic residues on the protease surface is pivotal for the folding of VPg via intermolecular edge-to-face π···π stacking between Trp271 and Trp368 of the protease and VPg, respectively, and for the CH···π interactions between Leu361 of VPg and Trp271 of the protease. The structure of the protease-VPg complex provides a molecular framework for predicting sites of important posttranslational modifications such as RNA linkage and phosphorylation and a better understanding of the coupled folding upon binding of intrinsically disordered proteins. The structural data presented here augment the limited structural data available on viral proteins, given their propensity for structural disorder.
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Affiliation(s)
- Karuna Dixit
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - N Megha Karanth
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Smita Nair
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Khushboo Kumari
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | | | - Handanahal S Savithri
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Siddhartha P Sarma
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka 560012, India
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Borden KLB, Volpon L. The diversity, plasticity, and adaptability of cap-dependent translation initiation and the associated machinery. RNA Biol 2020; 17:1239-1251. [PMID: 32496897 PMCID: PMC7549709 DOI: 10.1080/15476286.2020.1766179] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Translation initiation is a critical facet of gene expression with important impacts that underlie cellular responses to stresses and environmental cues. Its dysregulation in many diseases position this process as an important area for the development of new therapeutics. The gateway translation factor eIF4E is typically considered responsible for ‘global’ or ‘canonical’ m7G cap-dependent translation. However, eIF4E impacts translation of specific transcripts rather than the entire translatome. There are many alternative cap-dependent translation mechanisms that also contribute to the translation capacity of the cell. We review the diversity of these, juxtaposing more recently identified mechanisms with eIF4E-dependent modalities. We also explore the multiplicity of functions played by translation factors, both within and outside protein synthesis, and discuss how these differentially contribute to their ultimate physiological impacts. For comparison, we discuss some modalities for cap-independent translation. In all, this review highlights the diverse mechanisms that engage and control translation in eukaryotes.
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Affiliation(s)
- Katherine L B Borden
- Institute of Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal , Montreal, Québec, Canada
| | - Laurent Volpon
- Institute of Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Université de Montréal , Montreal, Québec, Canada
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Structural studies of the eIF4E-VPg complex reveal a direct competition for capped RNA: Implications for translation. Proc Natl Acad Sci U S A 2019; 116:24056-24065. [PMID: 31712417 DOI: 10.1073/pnas.1904752116] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Viruses have transformed our understanding of mammalian RNA processing, including facilitating the discovery of the methyl-7-guanosine (m7G) cap on the 5' end of RNAs. The m7G cap is required for RNAs to bind the eukaryotic translation initiation factor eIF4E and associate with the translation machinery across plant and animal kingdoms. The potyvirus-derived viral genome-linked protein (VPg) is covalently bound to the 5' end of viral genomic RNA (gRNA) and associates with host eIF4E for successful infection. Divergent models to explain these observations proposed either an unknown mode of eIF4E engagement or a competition of VPg for the m7G cap-binding site. To dissect these possibilities, we resolved the structure of VPg, revealing a previously unknown 3-dimensional (3D) fold, and characterized the VPg-eIF4E complex using NMR and biophysical techniques. VPg directly bound the cap-binding site of eIF4E and competed for m7G cap analog binding. In human cells, VPg inhibited eIF4E-dependent RNA export, translation, and oncogenic transformation. Moreover, VPg formed trimeric complexes with eIF4E-eIF4G, eIF4E bound VPg-luciferase RNA conjugates, and these VPg-RNA conjugates were templates for translation. Informatic analyses revealed structural similarities between VPg and the human kinesin EG5. Consistently, EG5 directly bound eIF4E in a similar manner to VPg, demonstrating that this form of engagement is relevant beyond potyviruses. In all, we revealed an unprecedented modality for control and engagement of eIF4E and show that VPg-RNA conjugates functionally engage eIF4E. As such, potyvirus VPg provides a unique model system to interrogate eIF4E.
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