scholarly journals The Vesicle-Forming 6K2Protein of Turnip Mosaic Virus Interacts with the COPII Coatomer Sec24a for Viral Systemic Infection

2015 ◽  
Vol 89 (13) ◽  
pp. 6695-6710 ◽  
Author(s):  
Jun Jiang ◽  
Camilo Patarroyo ◽  
Daniel Garcia Cabanillas ◽  
Huanquan Zheng ◽  
Jean-François Laliberté
Keyword(s):  
Arabidopsis Thaliana ◽  
Endoplasmic Reticulum ◽  
Mosaic Virus ◽  
Viral Protein ◽  
Cell Movement ◽  
Systemic Infection ◽  
Turnip Mosaic Virus ◽  
Tryptophan Residue ◽  
Content Type ◽  
Er Export

ABSTRACTPositive-sense RNA viruses remodel host cell endomembranes to generate quasi-organelles known as “viral factories” to coordinate diverse viral processes, such as genome translation and replication. It is also becoming clear that enclosing viral RNA (vRNA) complexes within membranous structures is important for virus cell-to-cell spread throughout the host. In plant cells infected by turnip mosaic virus (TuMV), a member of the familyPotyviridae, peripheral motile endoplasmic reticulum (ER)-derived viral vesicles are produced that carry the vRNA to plasmodesmata for delivery into adjacent noninfected cells. The viral protein 6K2is responsible for the formation of these vesicles, but how 6K2is involved in their biogenesis is unknown. We show here that 6K2is associated with cellular membranes. Deletion mapping and site-directed mutagenesis experiments defined a soluble N-terminal 12-amino-acid stretch, in particular a potyviral highly conserved tryptophan residue and two lysine residues that were important for vesicle formation. When the tryptophan residue was changed into an alanine in the viral polyprotein, virus replication still took place, albeit at a reduced level, but cell-to-cell movement of the virus was abolished. Yeast (Saccharomyces cerevisiae) two-hybrid and coimmunoprecipitation experiments showed that 6K2interacted with Sec24a, a COPII coatomer component. Appropriately, TuMV systemic movement was delayed in anArabidopsis thalianamutant line defective in Sec24a. Intercellular movement of TuMV replication vesicles thus requires ER export of 6K2, which is mediated by the interaction of the N-terminal domain of the viral protein with Sec24a.IMPORTANCEMany plant viruses remodel the endoplasmic reticulum (ER) to generate vesicles that are associated with the virus replication complex. The viral protein 6K2of turnip mosaic virus (TuMV) is known to induce ER-derived vesicles that contain vRNA as well as viral and host proteins required for vRNA synthesis. These vesicles not only sustain vRNA synthesis, they are also involved in the intercellular trafficking of vRNA. In this investigation, we found that the N-terminal soluble domain of 6K2is required for ER export of the protein and for the formation of vesicles. ER export is not absolutely required for vRNA replication but is necessary for virus cell-to-cell movement. Furthermore, we found that 6K2physically interacts with the COPII coatomer Sec24a and that anArabidopsis thalianamutant line with a defective Sec24a shows a delay in the systemic infection by TuMV.

scholarly journals Multiple aromatic amino acids are involved in potyvirus movement by forming π-stackings to maintain coat protein accumulation

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhi-Yong Yan ◽  
Xiao-Jie Xu ◽  
Le Fang ◽  
Chao Geng ◽  
Yan-Ping Tian ◽  
...  
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Infectious Clone ◽  
Three Dimensional ◽  
Cell Movement ◽  
Systemic Infection ◽  
Watermelon Mosaic Virus ◽  
Protein Accumulation ◽  
Three Dimensional Model ◽  
Aromatic Residues

AbstractCoat protein (CP) is required for potyviruses to move and establish a systemic infection in plants. π-stackings formed by aromatic residues play critical roles in maintaining protein stability and functions. As we know, many aromatic residues located in the core region of potyvirus CPs are conserved. However, their roles in potyvirus infection remain largely unknown. Here, through analysis of the three-dimensional model of the tobacco vein banding mosaic virus (TVBMV; genus Potyvirus) CP, 16 aromatic residues were predicated to form π-stackings. The results of transient expression experiments demonstrated that deletion of any of these 16 aromatic residues reduced CP accumulation. Infectivity assays showed that deletion of any of these aromatic residues in the TVBMV infectious clone abolished cell-to-cell movement and reduced replication of the virus. Substitution of Y105 and Y147 individually with non-aromatic residues alanine or glycine reduced CP accumulation, virus replication, and abolished the ability of TVBMV to move intercellularly, while substitution of these two residues individually with aromatic residues phenylalanine or tryptophan, had no or little effect on CP accumulation and TVBMV systemic movement and replication. Similar results were obtained from the CP mutants of watermelon mosaic virus (WMV, genus Potyvirus). Taken together, our results demonstrate that multiple aromatic residues in CP are involved in potyvirus movement by forming π-stackings to maintain CP accumulation.

scholarly journals Comparison of two Turnip mosaic virus P1 proteins in their ability to co-localize with the Arabidopsis thaliana G3BP-2 protein

Virus Genes ◽  
2021 ◽  
Vol 57 (2) ◽  
pp. 233-237
Author(s):  
Hendrik Reuper ◽  
Björn Krenz
Keyword(s):  
Arabidopsis Thaliana ◽  
Mosaic Virus ◽  
Specific Interaction ◽  
Viral Proteins ◽  
Turnip Mosaic Virus ◽  
Stress Conditions ◽  
C Terminus ◽  
Positive Sense ◽  
Key Factor ◽  
Large Host

AbstractTurnip mosaic virus (TuMV), belonging to the genus Potyvirus (family Potyviridae), has a large host range and consists of a single-stranded positive sense RNA genome encoding 12 proteins, including the P1 protease. This protein which is separated from the polyprotein by cis cleavage at its respective C-terminus, has been attributed with different functions during potyviral infection of plants. P1 of Turnip mosaic virus (P1-TuMV) harbors an FGSF-motif and FGSL-motif at its N-terminus. This motif is predicted to be a binding site for the host Ras GTPase-activating protein-binding protein (G3BP), which is a key factor for stress granule (SG) formation in mammalian systems and often targeted by viruses to inhibit SG formation. We therefore hypothesized that P1-TuMV might interact with G3BP to control and regulate plant SGs to optimize cellular conditions for the production of viral proteins. Here, we analyzed the co-localization of the Arabidopsis thaliana G3BP-2 with the P1 of two TuMV isolates, namely UK 1 and DEU 2. Surprisingly, P1-TuMV-DEU 2 co-localized with AtG3BP-2 under abiotic stress conditions, whereas P1-TuMV-UK 1 did not. AtG3BP-2::RFP showed strong SGs formation after stress, while P1-UK 1::eGFP maintained a chloroplastic signal under stress conditions, the signal of P1-DEU 2::eGFP co-localized with that of AtG3BP-2::RFP. This indicates a specific interaction between P1-DEU 2 and the AtG3BP family which is not solely based on the canonical interaction motifs.

scholarly journals The apparent non-host resistance of Ethiopian mustard to a radish-infecting strain of Turnip mosaic virus is largely determined by the C-terminal region of the P3 viral protein

2018 ◽  
Vol 19 (8) ◽  
pp. 1984-1994 ◽  
Author(s):  
Papaiah Sardaru ◽  
Laura Sinausía ◽  
Silvia López-González ◽  
Jelena Zindovic ◽  
Flora Sánchez ◽  
...  
Keyword(s):  
Mosaic Virus ◽  
Host Resistance ◽  
Viral Protein ◽  
Turnip Mosaic Virus ◽  
Terminal Region ◽  
Ethiopian Mustard

scholarly journals Cucumber mosaic virus Establishes Systemic Infection at Increased Temperature Following Viral Entrance Into the Phloem Pathway of Tetragonia expansa

2003 ◽  
Vol 93 (11) ◽  
pp. 1445-1451 ◽  
Author(s):  
Takashi Kobori ◽  
Takeshi Osaki ◽  
Satoshi T. Ohki
Keyword(s):  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Cell Movement ◽  
Systemic Infection ◽  
Regulatory Site ◽  
Mesophyll Cells ◽  
Increased Temperature ◽  
Tetragonia Expansa ◽  
Internal Phloem

A potential regulatory site for Cucumber mosaic virus (CMV, pepo strain) movement necessary to establish systemic infection was identified through immunological and hybridization studies on Tetragonia expansa, which was systemically infected by CMV at 36°C but not at 24°C. In inoculated leaves, cell-to-cell movement of CMV was enhanced at 36°C compared with that observed at 24°C. CMV was distributed in the phloem cells of minor veins as well as epidermal and mesophyll cells at both 36 and 24°C. CMV was detected in the petioles of inoculated leaves, stems, and petioles of uninoculated upper leaves at 36°C, whereas CMV was detected only in the petioles of inoculated leaves and in stems at 24°C. CMV moved into the phloem and was transported to the stem within 24 h postinoculation (hpi) at 36°C. However, it did not accumulate in the petioles of the upper leaves until 36 hpi. In petioles of inoculated leaves at 24°C, CMV was detected in the external phloem but not in the internal phloem. From these results, we conclude that systemic infection is established after viral entrance into the phloem pathway in T. expansa at 36°C.

scholarly journals The Rate of Cell-to-Cell Movement in Squash of Cucumber Mosaic Virus Is Affected by Sequences of the Capsid Protein

1999 ◽  
Vol 12 (7) ◽  
pp. 628-632 ◽  
Author(s):  
Sek-Man Wong ◽  
Sharon Swee-Chin Thio ◽  
Michael H. Shintaku ◽  
Peter Palukaitis
Keyword(s):  
Amino Acids ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Capsid Protein ◽  
Cell Movement ◽  
Systemic Infection ◽  
Long Distance ◽  
Local Movement ◽  
Long Distance Movement

The M strain of cucumber mosaic virus (CMV) does not infect squash plants systemically and moves very slowly in inoculated cotyledons. Systemic infection and an increase in the rate of local movement were observed when amino acids 129 or 214 of the M-CMV capsid protein (CP) were altered to those present in the Fny strain of CMV. While the opposite alterations to the CP of Fny-CMV inhibited systemic infection of squash, they did not show the same effects on the rates of both cell-to-cell and long-distance movement. However, the ability of CMV to infect squash systemically was affected by the rate of cell-to-cell movement.

scholarly journals Dysfunctionality of a tobacco mosaic virus movement protein mutant mimicking threonine 104 phosphorylation

2003 ◽  
Vol 84 (3) ◽  
pp. 727-732 ◽  
Author(s):  
E. M. Karger ◽  
O. Yu. Frolova ◽  
N. V. Fedorova ◽  
L. A. Baratova ◽  
T. V. Ovchinnikova ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Specific Protein ◽  
Virus Movement ◽  
Wild Type ◽  
Molecular Masses

Replication of tobacco mosaic virus (TMV) is connected with endoplasmic reticulum (ER)-associated membranes at early stages of infection. This study reports that TMV movement protein (MP)-specific protein kinases (PKs) associated with the ER of tobacco were capable of phosphorylating Thr104 in TMV MP. The MP-specific PKs with apparent molecular masses of about 45–50 kDa and 38 kDa were revealed by gel PK assays. Two types of mutations were introduced in TMV MP gene of wild-type TMV U1 genome to substitute Thr104 by neutral Ala or by negatively charged Asp. Mutation of Thr104 to Ala did not affect the size of necrotic lesions induced by the mutant virus in Nicotiana tabacum Xanthi nc. plants. Conversely, mutation of Thr to Asp mimicking Thr104 phosphorylation strongly inhibited cell-to-cell movement. The possible role of Thr104 phosphorylation in TMV MP function is discussed.

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