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Chen D, Zhang HY, Hu SM, He Z, Wu YQ, Zhang ZY, Wang Y, Han CG. The P2 protein of wheat yellow mosaic virus acts as a viral suppressor of RNA silencing in Nicotiana benthamiana to facilitate virus infection. PLANT, CELL & ENVIRONMENT 2024. [PMID: 39016637 DOI: 10.1111/pce.15041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/18/2024] [Accepted: 07/08/2024] [Indexed: 07/18/2024]
Abstract
Wheat yellow mosaic virus (WYMV) causes severe viral wheat disease in Asia. The WYMV P1 protein encoded by RNA2 has viral suppressor of RNA silencing (VSR) activity to facilitate virus infection, however, VSR activity has not been identified for P2 protein encoded by RNA2. In this study, P2 protein exhibited strong VSR activity in Nicotiana benthamiana at the four-leaf stage, and point mutants P70A and G230A lost VSR activity. Protein P2 interacted with calmodulin (CaM) protein, a gene-silencing associated protein, while point mutants P70A and G230A did not interact with it. Competitive bimolecular fluorescence complementation and competitive co-immunoprecipitation experiments showed that P2 interfered with the interaction between CaM and calmodulin-binding transcription activator 3 (CAMTA3), but the point mutants P70A and G230A could not. Mechanical inoculation of wheat with in vitro transcripts of WYMV infectious cDNA clone further confirmed that VSR-deficient mutants P70A and G230A decreased WYMV infection in wheat plants compared with the wild type. In addition, RNA silencing, temperature, ubiquitination and autophagy had significant effects on accumulation of P2 protein in N. benthamiana leaves. In conclusion, WYMV P2 plays a VSR role in N. benthamiana and promotes virus infection by interfering with calmodulin-related antiviral RNAi defense.
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Affiliation(s)
- Dao Chen
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Hui-Ying Zhang
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Shu-Ming Hu
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Zheng He
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Yong Qi Wu
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Zong-Ying Zhang
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Ying Wang
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
| | - Cheng-Gui Han
- Ministry of Agriculture and Rural Affairs Key Laboratory of Pest Monitoring and College of Plant Protection, China Agricultural University, Beijing, China
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Hýsková V, Bělonožníková K, Chmelík J, Hoffmeisterová H, Čeřovská N, Moravec T, Ryšlavá H. Potyviral Helper-Component Protease: Multifaced Functions and Interactions with Host Proteins. PLANTS (BASEL, SWITZERLAND) 2024; 13:1236. [PMID: 38732454 PMCID: PMC11085613 DOI: 10.3390/plants13091236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 04/25/2024] [Accepted: 04/26/2024] [Indexed: 05/13/2024]
Abstract
The best-characterized functional motifs of the potyviral Helper-Component protease (HC-Pro) responding for aphid transmission, RNA silencing suppression, movement, symptom development, and replication are gathered in this review. The potential cellular protein targets of plant virus proteases remain largely unknown despite their multifunctionality. The HC-Pro catalytic domain, as a cysteine protease, autoproteolytically cleaves the potyviral polyproteins in the sequence motif YXVG/G and is not expected to act on host targets; however, 146 plant proteins in the Viridiplantae clade containing this motif were searched in the UniProtKB database and are discussed. On the other hand, more than 20 interactions within the entire HC-Pro structure are known. Most of these interactions with host targets (such as the 20S proteasome, methyltransferase, transcription factor eIF4E, and microtubule-associated protein HIP2) modulate the cellular environments for the benefit of virus accumulation or contribute to symptom severity (interactions with MinD, Rubisco, ferredoxin) or participate in the suppression of RNA silencing (host protein VARICOSE, calmodulin-like protein). On the contrary, the interaction of HC-Pro with triacylglycerol lipase, calreticulin, and violaxanthin deepoxidase seems to be beneficial for the host plant. The strength of these interactions between HC-Pro and the corresponding host protein vary with the plant species. Therefore, these interactions may explain the species-specific sensitivity to potyviruses.
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Affiliation(s)
- Veronika Hýsková
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague, Czech Republic; (V.H.); (K.B.); or (J.C.)
| | - Kateřina Bělonožníková
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague, Czech Republic; (V.H.); (K.B.); or (J.C.)
| | - Josef Chmelík
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague, Czech Republic; (V.H.); (K.B.); or (J.C.)
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic
| | - Hana Hoffmeisterová
- Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02 Prague, Czech Republic; (H.H.); (N.Č.); (T.M.)
| | - Noemi Čeřovská
- Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02 Prague, Czech Republic; (H.H.); (N.Č.); (T.M.)
| | - Tomáš Moravec
- Institute of Experimental Botany of the Czech Academy of Sciences, Rozvojová 263, 165 02 Prague, Czech Republic; (H.H.); (N.Č.); (T.M.)
| | - Helena Ryšlavá
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 2030, 128 43 Prague, Czech Republic; (V.H.); (K.B.); or (J.C.)
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A Zinc Finger Motif in the P1 N Terminus, Highly Conserved in a Subset of Potyviruses, Is Associated with the Host Range and Fitness of Telosma Mosaic Virus. J Virol 2023; 97:e0144422. [PMID: 36688651 PMCID: PMC9972955 DOI: 10.1128/jvi.01444-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
P1 is the first protein translated from the genomes of most viruses in the family Potyviridae, and it contains a C-terminal serine-protease domain that cis-cleaves the junction between P1 and HCPro in most cases. Intriguingly, P1 is the most divergent among all mature viral factors, and its roles during viral infection are still far from understood. In this study, we found that telosma mosaic virus (TelMV, genus Potyvirus) in passion fruit, unlike TelMV isolates present in other hosts, has two stretches at the P1 N terminus, named N1 and N2, with N1 harboring a Zn finger motif. Further analysis revealed that at least 14 different potyviruses, mostly belonging to the bean common mosaic virus subgroup, encode a domain equivalent to N1. Using the newly developed TelMV infectious cDNA clones from passion fruit, we demonstrated that N1, but not N2, is crucial for viral infection in both Nicotiana benthamiana and passion fruit. The regulatory effects of N1 domain on P1 cis cleavage, as well as the accumulation and RNA silencing suppression (RSS) activity of its cognate HCPro, were comprehensively investigated. We found that N1 deletion decreases HCPro abundance at the posttranslational level, likely by impairing P1 cis cleavage, thus reducing HCPro-mediated RSS activity. Remarkably, disruption of the Zn finger motif in N1 did not impair P1 cis cleavage and HCPro accumulation but severely debilitated TelMV fitness. Therefore, our results suggest that the Zn finger motif in P1s plays a critical role in viral infection that is independent of P1 protease activity and self-release, as well as HCPro accumulation and silencing suppression. IMPORTANCE Viruses belonging to the family Potyviridae represent the largest group of plant-infecting RNA viruses, including a variety of agriculturally and economically important viral pathogens. Like all picorna-like viruses, potyvirids employ polyprotein processing as the gene expression strategy. P1, the first protein translated from most potyvirid genomes, is the most variable viral factor and has attracted great scientific interest. Here, we defined a Zn finger motif-encompassing domain (N1) at the N terminus of P1 among diverse potyviruses phylogenetically related to bean common mosaic virus. Using TelMV as a model virus, we demonstrated that the N1 domain is key for viral infection, as it is involved both in regulating the abundance of its cognate HCPro and in an as-yet-undefined key function unrelated to protease processing and RNA silencing suppression. These results advance our knowledge of the hypervariable potyvirid P1s and highlight the importance for infection of a previously unstudied Zn finger domain at the P1 N terminus.
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Pasin F, Daròs JA, Tzanetakis IE. OUP accepted manuscript. FEMS Microbiol Rev 2022; 46:6534904. [PMID: 35195244 PMCID: PMC9249622 DOI: 10.1093/femsre/fuac011] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 11/17/2022] Open
Abstract
Potyviridae, the largest family of known RNA viruses (realm Riboviria), belongs to the picorna-like supergroup and has important agricultural and ecological impacts. Potyvirid genomes are translated into polyproteins, which are in turn hydrolyzed to release mature products. Recent sequencing efforts revealed an unprecedented number of potyvirids with a rich variability in gene content and genomic layouts. Here, we review the heterogeneity of non-core modules that expand the structural and functional diversity of the potyvirid proteomes. We provide a family-wide classification of P1 proteinases into the functional Types A and B, and discuss pretty interesting sweet potato potyviral ORF (PISPO), putative zinc fingers, and alkylation B (AlkB)—non-core modules found within P1 cistrons. The atypical inosine triphosphate pyrophosphatase (ITPase/HAM1), as well as the pseudo tobacco mosaic virus-like coat protein (TMV-like CP) are discussed alongside homologs of unrelated virus taxa. Family-wide abundance of the multitasking helper component proteinase (HC-pro) is revised. Functional connections between non-core modules are highlighted to support host niche adaptation and immune evasion as main drivers of the Potyviridae evolutionary radiation. Potential biotechnological and synthetic biology applications of potyvirid leader proteinases and non-core modules are finally explored.
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Affiliation(s)
- Fabio Pasin
- Corresponding author: Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València (CSIC-UPV), UPV Building 8E, Ingeniero Fausto Elio, 46011 Valencia, Spain. E-mail:
| | - José-Antonio Daròs
- Instituto de Biología Molecular y Celular de Plantas (IBMCP), Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València (CSIC-UPV), 46011 Valencia, Spain
| | - Ioannis E Tzanetakis
- Department of Entomology and Plant Pathology, Division of Agriculture, University of Arkansas System, 72701 Fayetteville, AR, USA
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Wang Y, Shen W, Dai Z, Gou B, Liu H, Hu W, Qin L, Li Z, Tuo D, Cui H. Biological and Molecular Characterization of Two Closely Related Arepaviruses and Their Antagonistic Interaction in Nicotiana benthamiana. Front Microbiol 2021; 12:755156. [PMID: 34733264 PMCID: PMC8558625 DOI: 10.3389/fmicb.2021.755156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Accepted: 09/22/2021] [Indexed: 11/25/2022] Open
Abstract
Previously, our group characterized two closely related viruses from Areca catechu, areca palm necrotic ringspot virus (ANRSV) and areca palm necrotic spindle-spot virus (ANSSV). These two viruses share a distinct genomic organization of leader proteases and represent the only two species of the newly established genus Arepavirus of the family Potyviridae. The biological features of the two viruses are largely unknown. In this study, we investigated the pathological properties, functional compatibility of viral elements, and interspecies interactions in the model plant, Nicotiana benthamiana. Using a newly obtained infectious clone of ANRSV, we showed that this virus induces more severe symptoms compared with ANSSV and that this is related to a rapid virus multiplication in planta. A series of hybrid viruses were constructed via the substitution of multiple elements in the ANRSV infectious clone with the counterparts of ANSSV. The replacement of either 5′-UTR-HCPro1–HCPro2 or CI effectively supported replication and systemic infection of ANRSV, whereas individual substitution of P3-7K, 9K-NIa, and NIb-CP-3′-UTR abolished viral infectivity. Finally, we demonstrated that ANRSV confers effective exclusion of ANSSV both in coinfection and super-infection assays. These results advance our understanding of fundamental aspects of these two distinct but closely related arepaviruses.
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Affiliation(s)
- Yaodi Wang
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Wentao Shen
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Zhaoji Dai
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Bei Gou
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Hongjun Liu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Weiyao Hu
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Li Qin
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Zengping Li
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
| | - Decai Tuo
- Institute of Tropical Bioscience and Biotechnology, Chinese Academy of Tropical Agricultural Sciences, Haikou, China
| | - Hongguang Cui
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and Pests, Ministry of Education and College of Plant Protection, Hainan University, Haikou, China
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