Comparison of helper component-protease RNA silencing suppression activity, subcellular localization, and aggregation of three Korean isolates of Turnip mosaic virus

Virus Genes ◽  
2016 ◽  
Vol 52 (4) ◽  
pp. 592-596 ◽  
Author(s):  
Jae-Yeong Han ◽  
Jinsoo Chung ◽  
Jungkyu Kim ◽  
Eun-Young Seo ◽  
James P. Kilcrease ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Mosaic Virus ◽  
Rna Silencing ◽  
Turnip Mosaic Virus ◽  
Helper Component ◽  
Silencing Suppression

scholarly journals Genetic Analyses of the FRNK Motif Function of Turnip mosaic virus Uncover Multiple and Potentially Interactive Pathways of Cross-Protection

2014 ◽  
Vol 27 (9) ◽  
pp. 944-955 ◽  
Author(s):  
Yi-Jung Kung ◽  
Pin-Chun Lin ◽  
Shyi-Dong Yeh ◽  
Syuan-Fei Hong ◽  
Nam-Hai Chua ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Mosaic Virus ◽  
Rna Silencing ◽  
Turnip Mosaic Virus ◽  
Cross Protection ◽  
Mild Strain ◽  
Silencing Suppression ◽  
Helper Component Proteinase ◽  
Silencing Pathways ◽  
Protection Against Infection

Cross-protection triggered by a mild strain of virus acts as a prophylaxis to prevent subsequent infections by related viruses in plants; however, the underling mechanisms are not fully understood. Through mutagenesis, we isolated a mutant strain of Turnip mosaic virus (TuMV), named Tu-GK, that contains an Arg182Lys substitution in helper component-proteinase (HC-ProK) that confers complete cross-protection against infection by a severe strain of TuMV in Nicotiana benthamiana, Arabidopsis thaliana Col-0, and the Arabidopsis dcl2-4/dcl4-1 double mutant defective in DICER-like ribonuclease (DCL)2/DCL4-mediated silencing. Our analyses showed that HC-ProK loses the ability to interfere with microRNA pathways, although it retains a partial capability for RNA silencing suppression triggered by DCL. We further showed that Tu-GK infection triggers strong salicylic acid (SA)-dependent and SA-independent innate immunity responses. Our data suggest that DCL2/4-dependent and –independent RNA silencing pathways are involved, and may crosstalk with basal innate immunity pathways, in host defense and in cross-protection.

scholarly journals A Single Amino Acid Mutation in the Plum pox virus Helper Component-Proteinase Gene Abolishes Both Synergistic and RNA Silencing Suppression Activities

2005 ◽  
Vol 95 (8) ◽  
pp. 894-901 ◽  
Author(s):  
Pablo González-Jara ◽  
Felix A. Atencio ◽  
Belén Martínez-García ◽  
Daniel Barajas ◽  
Francisco Tenllado ◽  
...  
Keyword(s):  
Amino Acid ◽  
Point Mutation ◽  
Rna Silencing ◽  
Recombinant Virus ◽  
Single Amino Acid ◽  
Single Point Mutation ◽  
Plum Pox Virus ◽  
Helper Component ◽  
Silencing Suppression ◽  
Helper Component Proteinase

The effects on symptom expression of single amino acid mutations in the central region of the Plum pox virus (PPV) helper component-proteinase (HC-Pro) gene were analyzed in Nicotiana benthamiana using Potato virus X (PVX) recombinant viruses. PVX recombinant virus expressing the wild-type variant of PPV HC-Pro induced the expected enhancement of PVX pathogenicity, manifested as necrosis and plant death. Recombinant virus expressing a variant of PPV HC-Pro containing a single point mutation ( HCL134H) was unable to induce this synergistic phenotype. The RNA silencing suppressor activity of PPV HC-Pro was demonstrated in a transient silencing suppression assay. In contrast, the HCL134H mutant showed no such activity. These results indicate that a unique point mutation in PPV HC-Pro impaired its ability to suppress RNA silencing and abolished its capacity to induce synergism, and clearly shows for the first time the link between these two functions in potyvirus HC-Pro. Additionally, we compared the effects on virus accumulation in N. benthamiana plants infected with either the PVX recombinant constructs or with native viruses in double infection experiments. PVX (+) and (-) strand genomic RNA accumulated at similar levels in plants infected with PVX recombinants, leading to an increase in PVX pathology, compared with plants infected with PVX alone. This finding confirms that the enhancement of pathogenicity associated with synergistic interaction is not a consequence of more efficient PVX replication due to RNA silencing suppression by PPV HC-Pro.

scholarly journals Symptom induction and RNA silencing suppression by the cucumber mosaic virus 2b protein

2010 ◽  
Vol 5 (6) ◽  
pp. 705-708 ◽  
Author(s):  
Mathew G. Lewsey ◽  
Inmaculada González ◽  
Natalia O. Kalinina ◽  
Peter Palukaitis ◽  
Tomas Canto ◽  
...  
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Rna Silencing ◽  
2B Protein ◽  
Silencing Suppression

scholarly journals Multiple Domains of the Tobacco mosaic virus p126 Protein Can Independently Suppress Local and Systemic RNA Silencing

2012 ◽  
Vol 25 (5) ◽  
pp. 648-657 ◽  
Author(s):  
Li-Ya Wang ◽  
Shih-Shun Lin ◽  
Ting-Hsuan Hung ◽  
Tsai-Kun Li ◽  
Nai-Chun Lin ◽  
...  
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Rna Silencing ◽  
Large Size ◽  
Silencing Suppression ◽  
Systemic Rna ◽  
Multiple Domains ◽  
Region Ii ◽  
Suppressor Of Rna Silencing ◽  
Antiviral Mechanism

Small RNA-mediated RNA silencing is a widespread antiviral mechanism in plants and other organisms. Many viruses encode suppressors of RNA silencing for counter-defense. The p126 protein encoded by Tobacco mosaic virus (TMV) has been reported to be a suppressor of RNA silencing but the mechanism of its function remains unclear. This protein is unique among the known plant viral silencing suppressors because of its large size and multiple domains. Here, we report that the methyltransferase, helicase, and nonconserved region II (NONII) of p126 each has silencing-suppressor function. The silencing-suppression activities of methyltransferase and helicase can be uncoupled from their enzyme activities. Specific amino acids in NONII previously shown to be crucial for viral accumulation and symptom development are also crucial for silencing suppression. These results suggest that some viral proteins have evolved to possess modular structural domains that can independently interfere with host silencing, and that this may be an effective mechanism of increasing the robustness of a virus.

scholarly journals A Spontaneous Complementary Mutation Restores the RNA Silencing Suppression Activity of HC-Pro and the Virulence of Sugarcane Mosaic Virus

2020 ◽  
Vol 11 ◽  
Author(s):  
Xiao-Jie Xu ◽  
Huan-Gai Li ◽  
De-Jie Cheng ◽  
Ling-Zhi Liu ◽  
Chao Geng ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Rna Silencing ◽  
Sugarcane Mosaic Virus ◽  
Silencing Suppression

scholarly journals The Potyvirus Silencing Suppressor Protein VPg Mediates Degradation of SGS3 via Ubiquitination and Autophagy Pathways

2016 ◽  
Vol 91 (1) ◽  
Author(s):  
Xiaofei Cheng ◽  
Aiming Wang
Keyword(s):  
Mosaic Virus ◽  
Rna Silencing ◽  
Plant Viruses ◽  
Turnip Mosaic Virus ◽  
Host Protein ◽  
Ubiquitin Proteasome ◽  
Cellular Pathways ◽  
Viral Suppressors ◽  
Interfering Rna ◽  
Innate Antiviral Immunity

ABSTRACT RNA silencing is an innate antiviral immunity response of plants and animals. To counteract this host immune response, viruses have evolved an effective strategy to protect themselves by the expression of viral suppressors of RNA silencing (VSRs). Most potyviruses encode two VSRs, helper component-proteinase (HC-Pro) and viral genome-linked protein (VPg). The molecular biology of the former has been well characterized, whereas how VPg exerts its function in the suppression of RNA silencing is yet to be understood. In this study, we show that infection by Turnip mosaic virus (TuMV) causes reduced levels of suppressor of gene silencing 3 (SGS3), a key component of the RNA silencing pathway that functions in double-stranded RNA synthesis for virus-derived small interfering RNA (vsiRNA) production. We also demonstrate that among 11 TuMV-encoded viral proteins, VPg is the only one that interacts with SGS3. We furthermore present evidence that the expression of VPg alone, independent of viral infection, is sufficient to induce the degradation of SGS3 and its intimate partner RNA-dependent RNA polymerase 6 (RDR6). Moreover, we discover that the VPg-mediated degradation of SGS3 occurs via both the 20S ubiquitin-proteasome and autophagy pathways. Taken together, our data suggest a role for VPg-mediated degradation of SGS3 in suppression of silencing by VPg. IMPORTANCE Potyviruses represent the largest group of known plant viruses and cause significant losses of many agriculturally important crops in the world. In order to establish infection, potyviruses must overcome the host antiviral silencing response. A viral protein called VPg has been shown to play a role in this process, but how it works is unclear. In this paper, we found that the VPg protein of Turnip mosaic virus (TuMV), which is a potyvirus, interacts with a host protein named SGS3, a key protein in the RNA silencing pathway. Moreover, this interaction leads to the degradation of SGS3 and its interacting and functional partner RDR6, which is another essential component of the RNA silencing pathway. We also identified the cellular pathways that are recruited for the VPg-mediated degradation of SGS3. Therefore, this work reveals a possible mechanism by which VPg sabotages host antiviral RNA silencing to promote virus infection.

scholarly journals The cysteine-rich proteins of beet necrotic yellow vein virus and tobacco rattle virus contribute to efficient suppression of silencing in roots

2012 ◽  
Vol 93 (8) ◽  
pp. 1841-1850 ◽  
Author(s):  
Ida Bagus Andika ◽  
Hideki Kondo ◽  
Masamichi Nishiguchi ◽  
Tetsuo Tamada
Keyword(s):  
Mosaic Virus ◽  
Potato Virus ◽  
Rna Silencing ◽  
Tobacco Rattle Virus ◽  
Potato Virus X ◽  
Plant Viruses ◽  
Yellow Vein ◽  
Negative Strand ◽  
Silencing Suppression ◽  
Leaves And Roots

Many plant viruses encode proteins that suppress RNA silencing, but little is known about the activity of silencing suppressors in roots. This study examined differences in the silencing suppression activity of different viruses in leaves and roots of Nicotiana benthamiana plants. Infection by tobacco mosaic virus, potato virus Y and cucumber mosaic virus but not potato virus X (PVX) resulted in strong silencing suppression activity of a transgene in both leaves and roots, whereas infection by beet necrotic yellow vein virus (BNYVV) and tobacco rattle virus (TRV) showed transgene silencing suppression in roots but not in leaves. For most viruses tested, viral negative-strand RNA accumulated at a very low level in roots, compared with considerable levels of positive-strand genomic RNA. Co-inoculation of leaves with PVX and either BNYVV or TRV produced an increase in PVX negative-strand RNA and subgenomic RNA (sgRNA) accumulation in roots. The cysteine-rich proteins (CRPs) BNYVV p14 and TRV 16K showed weak silencing suppression activity in leaves. However, when either of these CRPs was expressed from a PVX vector, there was an enhancement of PVX negative-strand RNA and sgRNA accumulation in roots compared with PVX alone. Such enhancement of PVX sgRNAs was also observed by expression of CRPs of other viruses and the well-known suppressors HC-Pro and p19 but not of the potato mop-top virus p8 CRP. These results indicate that BNYVV- and TRV-encoded CRPs suppress RNA silencing more efficiently in roots than in leaves.

scholarly journals Purification and Characterization of Turnip Mosaic Virus Helper Component Protein

1999 ◽  
Vol 89 (7) ◽  
pp. 564-567 ◽  
Author(s):  
R. Y. Wang ◽  
T. P. Pirone
Keyword(s):  
Molecular Mass ◽  
Mosaic Virus ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Turnip Mosaic Virus ◽  
Biologically Active ◽  
Helper Component ◽  
Pass Through

The helper component (HC) protein of turnip mosaic virus (TuMV) was concentrated by differential centrifugation followed by ammonium sulfate precipitation. The partially purified HC was then loaded onto a Ni2+-resin column that bound the HC; a histidine tag was not required for binding. The HC eluted from the column migrated as a band of about 50 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In its native state, the HC did not pass through an ultrafiltration membrane with a molecular mass cutoff of 100 kDa, which suggested that the HC is in a multimeric form when it is biologically active. The molecular mass of the multimeric form was determined by gel filtration to be approximately 145 kDa. Purified HC retained its activity for several months at -20°C. Using a protein blotting-overlay protocol, purified HC interacted in vitro with an aphid-transmissible TuMV isolate, but not with a non-aphid-transmissible isolate.

Diverse conserved domains and a positively selected site in the sugarcane streak mosaic virus P1 protein are essential for RNA silencing suppression and protein stability

2020 ◽  
Vol 69 (7) ◽  
pp. 1390-1400
Author(s):  
Jian‐Sheng Chen ◽  
Shan‐Shan Liang ◽  
Sheng‐Ren Sun ◽  
Mona B. Damaj ◽  
Hua‐Ying Fu ◽  
...  
Keyword(s):  
Protein Stability ◽  
Mosaic Virus ◽  
Rna Silencing ◽  
Sugarcane Streak Mosaic Virus ◽  
Conserved Domains ◽  
Silencing Suppression

Sequence variability in the HC-Pro coding regions of Korean soybean mosaic virus isolates is associated with differences in RNA silencing suppression

2014 ◽  
Vol 159 (6) ◽  
pp. 1373-1383 ◽  
Author(s):  
Mei-Jia Li ◽  
Jung-Kyu Kim ◽  
Eun-Young Seo ◽  
Seok Myeong Hong ◽  
Eui-Il Hwang ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Rna Silencing ◽  
Soybean Mosaic Virus ◽  
Sequence Variability ◽  
Coding Regions ◽  
Silencing Suppression ◽  
Virus Isolates
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