scholarly journals Intracellular Localization and Movement Phenotypes of Alfalfa mosaic virus Movement Protein Mutants

2001 ◽  
Vol 14 (9) ◽  
pp. 1063-1074 ◽  
Author(s):  
Mei Huang ◽  
Laurian Jongejan ◽  
Huanquan Zheng ◽  
Lee Zhang ◽  
John F. Bol
Keyword(s):  
Mosaic Virus ◽  
Movement Protein ◽  
Intracellular Localization ◽  
Alfalfa Mosaic Virus ◽  
Epidermal Cells ◽  
Tissue Cell ◽  
Tubular Structures ◽  
Suspension Cells ◽  
Long Distance ◽  
Tobacco Suspension Cells

Thirteen mutations were introduced in the movement protein (MP) gene of Alfalfa mosaic virus (AMV) fused to the green fluorescent protein (GFP) gene and the mutant MP-GFP fusions were expressed transiently in tobacco protoplasts, tobacco suspension cells, and epidermal cells of tobacco leaves. In addition, the mutations were introduced in the MP gene of AMV RNA 3 and the mutant RNAs were used to infect tobacco plants. Ten mutants were affected in one or more of the following functions of MP: the formation of tubular structures on the surface of protoplasts, association with the endoplasmic reticulum (ER) of suspension cells and epidermal cells, targeting to punctate structures in the cell wall of epidermis cells, movement from transfected cells to adjacent cells in epidermis tissue, cell-to-cell movement, or long-distance movement in plants. The mutations point to functional domains of the MP and support the proposed order of events in AMV transport. Studies with several inhibitors indicate that actin or microtubule components of the cytoskeleton are not involved in tubule formation by AMV MP. Evidence was obtained that tubular structures on the surface of transfected protoplasts contain ER- or plasmalemma-derived material.

scholarly journals Role of the Alfalfa mosaic virus Movement Protein and Coat Protein in Virus Transport

2001 ◽  
Vol 14 (9) ◽  
pp. 1051-1062 ◽  
Author(s):  
Jesús A. Sánchez-Navarro ◽  
John F. Bol
Keyword(s):  
Amino Acids ◽  
Coat Protein ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Alfalfa Mosaic Virus ◽  
Cell Movement ◽  
Brome Mosaic Virus ◽  
Tubular Structures ◽  
Wild Type ◽  
Virus Transport

The movement protein (MP) and coat protein (CP) encoded by Alfalfa mosaic virus (AMV) RNA 3 are both required for virus transport. RNA 3 vectors that expressed nonfused green fluorescent protein (GFP), MP:GPF fusions, or GFP:CP fusions were used to study the functioning of mutant MP and CP in protoplasts and plants. C-terminal deletions of up to 21 amino acids did not interfere with the function of the CP in cell-to-cell movement, although some of these mutations interfered with virion assembly. Deletion of the N-terminal 11 or C-terminal 45 amino acids did not interfere with the ability of MP to assemble into tubular structures on the protoplast surface. Additionally, N- or C-terminal deletions disrupted tubule formation. A GFP:CP fusion was targeted specifically into tubules consisting of a wild-type MP. All MP deletion mutants that showed cell-to-cell and systemic movement in plants were able to form tubular structures on the surface of protoplasts. Brome mosaic virus (BMV) MP did not support AMV transport. When the C-terminal 48 amino acids were replaced by the C-terminal 44 amino acids of the AMV MP, however, the BMV/AMV chimeric protein permitted wild-type levels of AMV transport. Apparently, the C terminus of the AMV MP, although dispensable for cell-to-cell movement, confers specificity to the transport process.

scholarly journals Association of the Movement Protein of Alfalfa Mosaic Virus with the Endoplasmic Reticulum and Its Trafficking in Epidermal Cells of Onion Bulb Scales

1999 ◽  
Vol 12 (8) ◽  
pp. 680-690 ◽  
Author(s):  
Mei Huang ◽  
Lee Zhang
Keyword(s):  
Endoplasmic Reticulum ◽  
Mosaic Virus ◽  
Time Course ◽  
Insect Cells ◽  
Movement Protein ◽  
Alfalfa Mosaic Virus ◽  
Epidermal Cells ◽  
Onion Bulb ◽  
Cell Cortex ◽  
Intercellular Trafficking

To study the intercellular trafficking potential of alfalfa mosaic virus movement protein (AlMV MP) and the cellular structures that may assist in this activity, the AlMV MP gene was fused with the green fluorescent protein (GFP) gene and delivered into epidermal cells of onion bulb scales and Nicotiana tabacum (BY-2) suspension culture cells by biolistic gene bombardment. Its subcellular distribution as well as intracellular and intercellular trafficking in epidermal cells of onion bulb scales and in insect cells were systematically studied. Cells expressing the MP-GFP showed a fluorescent filamentous network in the cell cortex and fluorescent irregular bodies scattered in the cytoplasm and present in the cell wall. By 44 h post transfection with the MP-GFP construct, 56% of fluorescent sites consisted of clustered cells, whereas the fluorescent sites from cells bombarded with the free GFP construct consisted of isolated cells. Time course experiments demonstrated that the MP-GFP was able to move into adjacent cells from a primarily transfected cell. Optical serial sectioning studies suggested that the MP-GFP could target to the plasmodesmata, and move through them into neighboring cells. Furthermore, detailed fluorescence microscopy analyses of both tobacco and onion cells showed that the MP-GFP co-localized with the endoplasmic reticulum (ER). Subcellular fractionation of insect cells and immunoblotting analysis revealed that the MP-GFP behaves as an integral membrane protein. These results indicate that the MP-GFP is associated with the ER and suggest that the ER association may be important for intracellular and intercellular movement of the AlMV MP.

scholarly journals Alfalfa Mosaic Virus Movement Protein Induces Tubules in Plant Protoplasts

1997 ◽  
Vol 10 (8) ◽  
pp. 1010-1014 ◽  
Author(s):  
Huanquan Zheng ◽  
Guiling Wang ◽  
Lee Zhang
Keyword(s):  
Mosaic Virus ◽  
Movement Protein ◽  
Alfalfa Mosaic Virus ◽  
Green Fluorescence Protein ◽  
Virus Movement ◽  
Plant Protoplasts ◽  
Tubular Structures ◽  
Green Fluorescence ◽  
Tubule Formation ◽  
Fluorescence Protein

The alfalfa mosaic virus (AlMV) movement protein (MP) was fused with the green fluorescence protein (GFP). The MP-GFP fusion was transiently expressed in protoplasts prepared from Nicotiana tabacum, resulting in the production of long, extending, tubular structures protruding from the protoplast surface. Deletions of MP amino acids 1 to 77, 84 to 142, or 226 to 300 all affected tubule formation. Hence, the AlMV MP is solely required for the induction of the tubular structures, and the results suggest that AlMV may move from cell to cell via tubules.

scholarly journals Heterologous Movement Protein Strongly Modifies the Infection Phenotype of Cucumber Mosaic Virus

2002 ◽  
Vol 76 (7) ◽  
pp. 3554-3557 ◽  
Author(s):  
Emese Huppert ◽  
Dénes Szilassy ◽  
Katalin Salánki ◽  
Zoltán Divéki ◽  
Ervin Balázs
Keyword(s):  
Nicotiana Tabacum ◽  
Virus Infection ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Host Plants ◽  
Movement Protein ◽  
Long Distance ◽  
Cucumber Mosaic Cucumovirus ◽  
Nicotiana Debneyi ◽  
Symptom Phenotype

ABSTRACT A hybrid virus (CMVcymMP) constructed by replacing the movement protein (MP) of cucumber mosaic cucumovirus (CMV) with that of cymbidium ringspot tombusvirus (CymRSV) was viable and could efficiently spread both cell to cell and long distance in host plants. The hybrid virus was able to move cell to cell in the absence of functional CP, whereas CP-deficient CMV was restricted to single inoculated cells. In several Chenopodium and Nicotiana species, the symptom phenotype of the hybrid virus infection was clearly determined by the foreign MP gene. In Nicotiana debneyi and Nicotiana tabacum cv. Xanthi, the hybrid virus could move systemically, contrary to CymRSV.

scholarly journals Spontaneous Mutation in the Movement Protein of Citrus Leprosis Virus C2, in a Heterologous Virus Infection Context, Increases Cell-to-Cell Transport and Generates Fitness Advantage

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2498
Author(s):  
Mikhail Oliveira Leastro ◽  
David Villar-Álvarez ◽  
Juliana Freitas-Astúa ◽  
Elliot Watanabe Kitajima ◽  
Vicente Pallás ◽  
...  
Keyword(s):  
Movement Protein ◽  
Spontaneous Mutation ◽  
Alfalfa Mosaic Virus ◽  
Viral Fitness ◽  
Viral Population ◽  
Long Distance ◽  
Cell Transport ◽  
Fitness Advantage ◽  
Citrus Leprosis ◽  
Virus C

Previous results using a movement defective alfalfa mosaic virus (AMV) vector revealed that citrus leprosis virus C (CiLV-C) movement protein (MP) generates a more efficient local movement, but not more systemic transport, than citrus leprosis virus C2 (CiLV-C2) MP, MPs belonging to two important viruses for the citrus industry. Here, competition experiment assays in transgenic tobacco plants (P12) between transcripts of AMV constructs expressing the cilevirus MPs, followed by several biological passages, showed the prevalence of the AMV construct carrying the CiLV-C2 MP. The analysis of AMV RNA 3 progeny recovered from P12 plant at the second viral passage revealed the presence of a mix of progeny encompassing the CiLV-C2 MP wild type (MPWT) and two variants carrying serines instead phenylalanines at positions 72 (MPS72F) or 259 (MPS259F), respectively. We evaluated the effects of each modified residue in virus replication, and cell-to-cell and long-distance movements. Results indicated that phenylalanine at position 259 favors viral cell-to-cell transport with an improvement in viral fitness, but has no effect on viral replication, whereas mutation at position 72 (MPS72F) has a penalty in the viral fitness. Our findings indicate that the prevalence of a viral population may be correlated with its greater efficiency in cell-to-cell and systemic movements.

scholarly journals Systemic transport of Alfalfa mosaic virus can be mediated by the movement proteins of several viruses assigned to five genera of the 30K family

2013 ◽  
Vol 94 (3) ◽  
pp. 677-681 ◽  
Author(s):  
Thor V. M. Fajardo ◽  
Ana Peiró ◽  
Vicente Pallás ◽  
Jesús Sánchez-Navarro
Keyword(s):  
Mosaic Virus ◽  
Movement Protein ◽  
Alfalfa Mosaic Virus ◽  
Brome Mosaic Virus ◽  
Virus Movement ◽  
Cell Transport ◽  
Movement Proteins ◽  
C Terminus ◽  
Prunus Necrotic Ringspot Virus ◽  
Systemic Transport

We previously showed that the movement protein (MP) gene of Alfalfa mosaic virus (AMV) is functionally exchangeable for the cell-to-cell transport of the corresponding genes of Tobacco mosaic virus (TMV), Brome mosaic virus, Prunus necrotic ringspot virus, Cucumber mosaic virus and Cowpea mosaic virus. We have analysed the capacity of the heterologous MPs to systemically transport the corresponding chimeric AMV genome. All MPs were competent in systemic transport but required the fusion at their C terminus of the coat protein-interacting C-terminal 44 aa (A44) of the AMV MP. Except for the TMV MP, the presence of the hybrid virus in upper leaves correlated with the capacity to move locally. These results suggest that all the MPs assigned to the 30K superfamily should be exchangeable not only for local virus movement but also for systemic transport when the A44 fragment is present.

Nucleic acid-binding properties of the alfalfa mosaic virus movement protein produced in yeast

Virology ◽  
1992 ◽  
Vol 188 (2) ◽  
pp. 896-899 ◽  
Author(s):  
Fabrice Schoumacher ◽  
Claude Erny ◽  
Anne Berna ◽  
Therese Godefroy-Colburn ◽  
Christiane Stussi-Garaud
Keyword(s):  
Nucleic Acid ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Alfalfa Mosaic Virus ◽  
Virus Movement ◽  
Nucleic Acid Binding ◽  
Binding Properties

scholarly journals Coordinate Replication of Alfalfa Mosaic Virus RNAs 1 and 2 Involves cis- and trans-Acting Functions of the Encoded Helicase-Like and Polymerase-Like Domains

2003 ◽  
Vol 77 (20) ◽  
pp. 10790-10798 ◽  
Author(s):  
A. Corina Vlot ◽  
Sebastiaan M. Laros ◽  
John F. Bol
Keyword(s):  
Mosaic Virus ◽  
Movement Protein ◽  
Alfalfa Mosaic Virus ◽  
Plant Leaves ◽  
Wild Type ◽  
Viral Rnas ◽  
Replicase Proteins ◽  
Gdd Motif ◽  
Cis And Trans ◽  
Competition Assays

ABSTRACT RNAs 1 and 2 of the tripartite genome of alfalfa mosaic virus encode the replicase proteins P1 and P2, respectively, whereas RNA 3 encodes the movement protein and coat protein. Transient expression of wild-type (wt) and mutant viral RNAs and proteins by agroinfiltration of plant leaves was used to study cis- and trans-acting functions of the helicase-like domain in P1 and the polymerase-like domain in P2. Three mutations in conserved motifs of the helicase-like domain of P1 affected one or more steps leading to synthesis of minus-strand RNAs 1, 2, and 3. In leaves containing transiently expressed P1 and P2, replication of wt but not mutant RNA 1 was observed. Apparently, the transiently expressed P1 could not complement the defect in replication of the RNA 1 mutant. Moreover, the transiently expressed wt replicase supported replication of RNA 2, but this replication was blocked in trans by coexpression of mutant RNA 1. However, expression of mutant RNA 1 did not interfere with the replication of RNA 3 by the wt replicase. Similarly, a mutation in the GDD motif encoded by RNA 2 could not be complemented in trans and affected the replication of RNA 1 by a wt replicase, while replication of RNA 3 remained unaffected. In competition assays, the transient wt replicase preferentially replicated RNA 3 over RNAs 1 and 2. The results indicate that one or more functions of P1 and P2 act in cis and point to the existence of a mechanism that coordinates the replication of RNAs 1 and 2.

scholarly journals The N-Terminal Domain of PMTV TGB1 Movement Protein Is Required for Nucleolar Localization, Microtubule Association, and Long-Distance Movement

2010 ◽  
Vol 23 (11) ◽  
pp. 1486-1497 ◽  
Author(s):  
Kathryn M. Wright ◽  
Graham H. Cowan ◽  
Nina I. Lukhovitskaya ◽  
Jens Tilsner ◽  
Alison G. Roberts ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fluorescent Protein ◽  
Movement Protein ◽  
Leading Edge ◽  
Epidermal Cells ◽  
Viral Rna ◽  
Nucleolar Localization ◽  
Long Distance ◽  
Long Distance Movement ◽  
In Cells

The triple-gene-block (TGB)1 protein of Potato mop-top virus (PMTV) was fused to fluorescent proteins and expressed in epidermal cells of Nicotiana benthamiana under the control of the 35S promoter. TGB1 fluorescence was observed in the cytoplasm, nucleus, and nucleolus and occasionally associated with microtubules. When expressed from a modified virus (PMTV.YFP-TGB1) which formed local lesions but was not competent for systemic movement, yellow fluorescent protein (YFP)-TGB1 labeled plasmodesmata in cells at the leading edge of the lesion and plasmodesmata, microtubules, nuclei, and nucleoli in cells immediately behind the leading edge. Deletion of 84 amino acids from the N-terminus of unlabeled TGB1 within the PMTV genome abolished movement of viral RNA to noninoculated leaves. When the same deletion was introduced into PMTV.YFP-TGB1, labeling of microtubules and nucleoli was abolished. The N-terminal 84 amino acids of TGB1 were fused to green fluorescent protein (GFP) and expressed in epidermal cells where GFP localized strongly to the nucleolus (not seen with unfused GFP), indicating that these amino acids contain a nucleolar localization signal; the fusion protein did not label microtubules. This is the first report of nucleolar and microtubule association of a TGB movement protein. The results suggest that PMTV TGB1 requires interaction with nuclear components and, possibly, microtubules for long-distance movement of viral RNA.

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