scholarly journals Tobamovirus Replicase Coding Region Is Involved in Cell-to-Cell Movement

2001 ◽  
Vol 75 (18) ◽  
pp. 8831-8836 ◽  
Author(s):  
Kyotaro Hirashima ◽  
Yuichiro Watanabe
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Tobacco Mosaic Virus ◽  
Host Range ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Coding Region ◽  
Replicase Proteins ◽  
Viral Movement

ABSTRACT Tobacco mosaic virus (TMV) encodes a 30-kDa movement protein (MP) which enables viral movement from cell to cell. It is, however, unclear whether the 126- and 183-kDa replicase proteins are involved in the cell-to-cell movement of TMV. In the course of our studies into TMV-R, a strain with a host range different from that of TMV-U1, we have obtained an interesting chimeric virus, UR-hel. The amino acid sequence differences between UR-hel and TMV-U1 are located only in the helicase-like domain of the replicase. Interestingly, UR-hel has a defect in its cell-to-cell movement. The replication of UR-hel showed a level of replication of the genome, synthesis, and accumulation of MP similar to that observed in TMV-U1-inoculated protoplasts. Such observations support the hypothesis that the replicase coding region may in some fashion be involved in cell-to-cell movement of TMV.

scholarly journals RNA Helicase Domain of Tobamovirus Replicase Executes Cell-to-Cell Movement Possibly through Collaboration with Its Nonconserved Region

2003 ◽  
Vol 77 (22) ◽  
pp. 12357-12362 ◽  
Author(s):  
Kyotaro Hirashima ◽  
Yuichiro Watanabe
Keyword(s):  
Amino Acid ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Rna Helicase ◽  
Chimeric Virus ◽  
Amino Acid Substitutions ◽  
Helicase Domain ◽  
Phenotypic Reversion

ABSTRACT UR-hel, a chimeric virus obtained by replacement of the RNA helicase domain of tobacco mosaic virus (TMV)-U1 replicase with that from the TMV-R strain, could replicate similarly to TMV-U1 in protoplasts but could not move from cell to cell (K. Hirashima and Y. Watanabe, J. Virol. 75:8831-8836, 2001). It was suggested that TMV recruited both the movement protein (MP) and replicase for cell-to-cell movement by unknown mechanisms. Here, we found that a recombinant, UR-hel/V, in which the nonconserved region was derived from TMV-R in addition to the RNA helicase domain of replicase, could move from cell to cell. We also analyzed revertants isolated from UR-hel, which recovered cell-to-cell movement by their own abilities. We found amino acid substitutions responsible for phenotypic reversion only in the nonconserved region and/or RNA helicase domain but never in MP. Together, these data show that both the nonconserved region and the RNA helicase domain of replicase are involved in cell-to-cell movement. The RNA helicase domain of tobamovirus replicase possibly does not interact directly with MP but interacts with its nonconserved region to execute cell-to-cell movement.

scholarly journals Tobacco mosaic virus: a pioneer to cell–to–cell movement

1999 ◽  
Vol 354 (1383) ◽  
pp. 637-643 ◽  
Author(s):  
Vitaly Citovsky
Keyword(s):  
Cell Wall ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Host Cells ◽  
Specific Cell ◽  
Viral Movement Protein ◽  
Rna Molecules ◽  
Rna Complexes

Cell–to–cell movement of tobacco mosaic virus (TMV) is used to illustrate macromolecular traffic through plant intercellular connections, the plasmodesmata. This transport process is mediated by a specialized viral movement protein, P30. In the initially infected cell, P30 is produced by transcription of a subgenomic RNA derived from the invading virus. Presumably, P30 then associates with a certain proportion of the viral RNA molecules, sequestering them from replication and mediating their transport into neighbouring uninfected host cells. This nucleoprotein complex is targeted to plasmodesmata, possibly via interaction with the host cell cytoskeleton. Prior to passage through a plasmodesma, the plasmodesmal channel is dilated by the movement protein. It is proposed that targeting of P30–TMV RNA complexes to plasmodesmata involves binding to a specific cell wall–associated receptor molecule. In addition, a cell wall–associated protein kinase, phosphorylates P30 at its carboxy–terminus and minimizes P30–induced interference with plasmodesmatal permeability during viral infection.

Die primäre Proteinstruktur von Stämmen des Tabakmosaikvirus

1963 ◽  
Vol 18 (12) ◽  
pp. 1032-1049 ◽  
Author(s):  
B. Wittmann-Liebold ◽  
H. G. Wittmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Amino Acid Sequences ◽  
Tryptic Peptides

The amino acid sequence of dahlemense, a naturally occuring strain of tobacco mosaic virus, has been determined and compared with that of the strain vulgare (Fig. 7). In this communication the experimental details are given for the elucidation of the amino acid sequences within two tryptic peptides with 65 amino acids.

scholarly journals Actin Cytoskeleton Is Involved in Targeting of a Viral Hsp70 Homolog to the Cell Periphery

2005 ◽  
Vol 79 (22) ◽  
pp. 14421-14428 ◽  
Author(s):  
Alexey I. Prokhnevsky ◽  
Valera V. Peremyslov ◽  
Valerian V. Dolja
Keyword(s):  
Actin Cytoskeleton ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Fluorescent Proteins ◽  
Cell Movement ◽  
Plant Viruses ◽  
Cell Periphery ◽  
Virus Particles ◽  
Shock Proteins

ABSTRACT The cell-to-cell movement of plant viruses involves translocation of virus particles or nucleoproteins to and through the plasmodesmata (PDs). As we have shown previously, the movement of the Beet yellows virus requires the concerted action of five viral proteins including a homolog of cellular ∼70-kDa heat shock proteins (Hsp70h). Hsp70h is an integral component of the virus particles and is also found in PDs of the infected cells. Here we investigate subcellular distribution of Hsp70h using transient expression of Hsp70h fused to three spectrally distinct fluorescent proteins. We found that fluorophore-tagged Hsp70h forms motile granules that are associated with actin microfilaments, but not with microtubules. In addition, immobile granules were observed at the cell periphery. A pairwise appearance of these granules at the opposite sides of cell walls and their colocalization with the movement protein of Tobacco mosaic virus indicated an association of Hsp70h with PDs. Treatment with various cytoskeleton-specific drugs revealed that the intact actomyosin motility system is required for trafficking of Hsp70h in cytosol and its targeting to PDs. In contrast, none of the drugs interfered with the PD localization of Tobacco mosaic virus movement protein. Collectively, these findings suggest that Hsp70h is translocated and anchored to PDs in association with the actin cytoskeleton.

Studies on the amino acid sequence of tobacco mosaic virus protein

1964 ◽  
Vol 105 (1) ◽  
pp. 42-50 ◽  
Author(s):  
Chun Ming Tsung ◽  
Gunki Funatsu ◽  
Janis Dillaha Young
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Virus Protein

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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