Natural isolates of Brome mosaic virus with the ability to move from cell to cell independently of coat protein

2005 ◽  
Vol 86 (4) ◽  
pp. 1201-1211 ◽  
Author(s):  
Atsushi Takeda ◽  
Wakako Nakamura ◽  
Nobumitsu Sasaki ◽  
Kaku Goto ◽  
Masanori Kaido ◽  
...  
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Mutational Analysis ◽  
Cell Movement ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Single Amino Acid ◽  
In Planta ◽  
C Terminus ◽  
Natural Isolates

Brome mosaic virus (BMV) requires encapsidation-competent coat protein (CP) for cell-to-cell movement and the 3a movement protein (MP) is involved in determining the CP requirement for BMV movement. However, these conclusions have been drawn by using BMV strain M1 (BMV-M1) and a related strain. Here, the ability of the MPs of five other natural BMV strains to mediate the movement of BMV-M1 in the absence of CP was tested. The MP of BMV M2 strain (BMV-M2) efficiently mediated the movement of CP-deficient BMV-M1 and the MPs of two other strains functioned similarly to some extent. Furthermore, BMV-M2 itself moved between cells independently of CP, demonstrating that BMV-M1 and -M2 use different movement modes. Reassortment between CP-deficient BMV-M1 and -M2 showed the involvement of RNA3 in determining the CP requirement for cell-to-cell movement and the involvement of RNAs 1 and 2 in movement efficiency and symptom induction in the absence of CP. Spontaneous BMV MP mutants generated in planta that exhibited CP-independent movement were also isolated and analysed. Comparison of the nucleotide differences of the MP genes of BMV-M1, the natural strains and mutants capable of CP-independent movement, together with further mutational analysis of BMV-M1 MP, revealed that single amino acid differences at the C terminus of MP are sufficient to alter the requirement for CP in the movement of BMV-M1. Based on these findings, a possible virus strategy in which a movement mode is selected in plant viruses to optimize viral infectivity in plants is discussed.

Characterization of a Novel Barley Protein, HCP1, That Interacts with the Brome mosaic virus Coat Protein

2003 ◽  
Vol 16 (4) ◽  
pp. 352-359 ◽  
Author(s):  
Yasushi Okinaka ◽  
Kazuyuki Mise ◽  
Tetsuro Okuno ◽  
Iwao Furusawa
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Brome Mosaic Virus ◽  
Host Factors ◽  
Single Amino Acid ◽  
Cdna Clones ◽  
Long Distance ◽  
C Terminus ◽  
Barley Protein ◽  
Two Hybrid

Brome mosaic virus (BMV) requires the coat protein (CP) not only for encapsidation but also for viral cell-to-cell and long-distance movement in barley plants. This suggests that BMV infection is controlled by interactions of CP with putative host factors as well as with viral components. To identify the host factors that interact with BMV CP, we screened a barley cDNA library containing 2.4 × 106 independent clones, using a yeast two-hybrid system. Using full-length and truncated BMV CPs as baits, four candidate cDNA clones were isolated. One of the candidate cDNAs encodes a unique oxidoreductase enzyme, designated HCP1. HCP1 was found predominantly in the soluble fractions after differential centrifugation of BMV-infected and mock-inoculated barley tissues. A two-hybrid binding assay using a series of truncated BMV CPs demonstrated that a C-terminal portion of CP is essential for its interaction with HCP1. Interestingly, experiments with CP mutants bearing single amino acid substitutions at the C-terminus revealed that the capacity for mutant CP-HCP1 binding correlates well with the infectivity of the corresponding mutant viruses in barley. These results indicate that CP-HCP1 binding controls BMV infection of barley, interacting directly with CP, probably in the cell cytoplasm.

scholarly journals Conversion in the Requirement of Coat Protein in Cell-to-Cell Movement Mediated by the Cucumber Mosaic Virus Movement Protein

2001 ◽  
Vol 75 (17) ◽  
pp. 8045-8053 ◽  
Author(s):  
Hideaki Nagano ◽  
Kazuyuki Mise ◽  
Iwao Furusawa ◽  
Tetsuro Okuno
Keyword(s):  
Amino Acids ◽  
Coat Protein ◽  
Cucumber Mosaic Virus ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Viral Movement ◽  
Intercellular Movement

ABSTRACT Plant viruses have movement protein (MP) gene(s) essential for cell-to-cell movement in hosts. Cucumber mosaic virus (CMV) requires its own coat protein (CP) in addition to the MP for intercellular movement. Our present results using variants of both CMV and a chimeric Brome mosaic virus with the CMV MP gene revealed that CMV MP truncated in its C-terminal 33 amino acids has the ability to mediate viral movement independently of CP. Coexpression of the intact and truncated CMV MPs extremely reduced movement of the chimeric viruses, suggesting that these heterogeneous CMV MPs function antagonistically. Sequential deletion analyses of the CMV MP revealed that the dispensability of CP occurred when the C-terminal deletion ranged between 31 and 36 amino acids and that shorter deletion impaired the ability of the MP to promote viral movement. This is the first report that a region of MP determines the requirement of CP in cell-to-cell movement of a plant virus.

scholarly journals The C terminus of the movement protein of Brome mosaic virus controls the requirement for coat protein in cell-to-cell movement and plays a role in long-distance movement

2004 ◽  
Vol 85 (6) ◽  
pp. 1751-1761 ◽  
Author(s):  
Atsushi Takeda ◽  
Masanori Kaido ◽  
Tetsuro Okuno ◽  
Kazuyuki Mise
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Movement Protein ◽  
Cell Movement ◽  
Brome Mosaic Virus ◽  
Wild Type ◽  
Long Distance ◽  
C Terminus ◽  
Mouth Disease Virus ◽  
Long Distance Movement

The 3a movement protein (MP) plays a central role in the movement of Brome mosaic virus (BMV). To identify the functional regions in BMV MP, 24 alanine-scanning (AS) MP mutants of BMV were constructed. Infectivity of the AS mutants in the host plant Chenopodium quinoa showed that the central region of BMV MP is important for viral movement and both termini of BMV MP have effects on the development of systemic symptoms. A green-fluorescent-protein-expressing RNA3-based BMV vector containing a 2A sequence from Foot-and-mouth disease virus was also constructed. Using this vector, two AS mutants that showed more efficient cell-to-cell movement than wild-type BMV were identified. The MPs of these two AS mutants, which have mutations at their C termini, mediated cell-to-cell movement independently of coat protein (CP), unlike wild-type BMV MP. Furthermore, a BMV mutant with a truncation in the C-terminal 42 amino acids of MP was also able to move from cell to cell without CP, but did not move systemically, even in the presence of CP. These results and an encapsidation analysis suggest that the C terminus of BMV MP is involved in the requirement for CP in cell-to-cell movement and plays a role in long-distance movement. Furthermore, the ability to spread locally and form virions is not sufficient for the long-distance movement of BMV. The roles of MP and CP in BMV movement are discussed.

scholarly journals tRNA-Like Structure Regulates Translation of Brome Mosaic Virus RNA

2004 ◽  
Vol 78 (8) ◽  
pp. 4003-4010 ◽  
Author(s):  
Sharief Barends ◽  
Joëlle Rudinger-Thirion ◽  
Catherine Florentz ◽  
Richard Giegé ◽  
Cornelis W. A. Pleij ◽  
...  
Keyword(s):  
Coat Protein ◽  
Protein Expression ◽  
Mosaic Virus ◽  
Dominant Role ◽  
Initiation Site ◽  
Plant Viruses ◽  
Brome Mosaic Virus ◽  
Trna Synthetase ◽  
Yellow Mosaic Virus ◽  
Genomic Rnas

ABSTRACT For various groups of plant viruses, the genomic RNAs end with a tRNA-like structure (TLS) instead of the 3′ poly(A) tail of common mRNAs. The actual function of these TLSs has long been enigmatic. Recently, however, it became clear that for turnip yellow mosaic virus, a tymovirus, the valylated TLSTYMV of the single genomic RNA functions as a bait for host ribosomes and directs them to the internal initiation site of translation (with N-terminal valine) of the second open reading frame for the polyprotein. This discovery prompted us to investigate whether the much larger TLSs of a different genus of viruses have a comparable function in translation. Brome mosaic virus (BMV), a bromovirus, has a tripartite RNA genome with a subgenomic RNA4 for coat protein expression. All four RNAs carry a highly conserved and bulky 3′ TLSBMV (about 200 nucleotides) with determinants for tyrosylation. We discovered TLSBMV-catalyzed self-tyrosylation of the tyrosyl-tRNA synthetase but could not clearly detect tyrosine incorporation into any virus-encoded protein. We established that BMV proteins do not need TLSBMV tyrosylation for their initiation. However, disruption of the TLSs strongly reduced the translation of genomic RNA1, RNA2, and less strongly, RNA3, whereas coat protein expression from RNA4 remained unaffected. This aberrant translation could be partially restored by providing the TLSBMV in trans. Intriguingly, a subdomain of the TLSBMV could even almost fully restore translation to the original pattern. We discuss here a model with a central and dominant role for the TLSBMV during the BMV infection cycle.

scholarly journals Phosphorylation of Coat Protein by Protein Kinase CK2 Regulates Cell-to-Cell Movement of Bamboo mosaic virus Through Modulating RNA Binding

2014 ◽  
Vol 27 (11) ◽  
pp. 1211-1225 ◽  
Author(s):  
Chien-Jen Hung ◽  
Ying-Wen Huang ◽  
Ming-Ru Liou ◽  
Ya-Chien Lee ◽  
Na-Sheng Lin ◽  
...  
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Binding Affinity ◽  
Rna Binding ◽  
Cell Movement ◽  
Viral Rna ◽  
In Planta ◽  
Binding Preference ◽  
Fine Regulation ◽  
Kinase Ck2

In this study, we investigated the fine regulation of cell-to-cell movement of Bamboo mosaic virus (BaMV). We report that the coat protein (CP) of BaMV is phosphorylated in planta at position serine 241 (S241), in a process involving Nicotiana benthamiana casein kinase 2α (NbCK2α). BaMV CP and NbCK2α colocalize at the plasmodesmata, suggesting that phosphorylation of BaMV may be involved in its movement. S241 was mutated to examine the effects of temporal and spatial dysregulation of phosphorylation on i) the interactions between CP and viral RNA and ii) the regulation of cell-to-cell movement. Replacement of S241 with alanine did not affect RNA binding affinity but moderately impaired cell-to-cell movement. A negative charge at position 241 reduced the ability of CP to bind RNA and severely interfered with cell-to-cell movement. Deletion of residues 240 to 242 increased the affinity of CP to viral RNA and dramatically impaired cell-to-cell movement. A threonine at position 241 changed the binding preference of CP toward genomic RNA and inhibited cell-to-cell movement. Together, these results reveal a fine regulatory mechanism for the cell-to-cell movement of BaMV, which involves the modulation of RNA binding affinity through appropriate phosphorylation of CP by NbCK2α.

scholarly journals The C Terminus of Brome Mosaic Virus Coat Protein Controls Viral Cell-to-Cell and Long-Distance Movement

2001 ◽  
Vol 75 (11) ◽  
pp. 5385-5390 ◽  
Author(s):  
Yasushi Okinaka ◽  
Kazuyuki Mise ◽  
Eri Suzuki ◽  
Tetsuro Okuno ◽  
Iwao Furusawa
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Plant Species ◽  
Rna Virus ◽  
Brome Mosaic Virus ◽  
Long Distance ◽  
C Terminus ◽  
Specific Factors ◽  
Virus Coat ◽  
Long Distance Movement

ABSTRACT To investigate the functional domains of the coat protein (CP; 189 amino acids) of Brome mosaic virus, a plant RNA virus, 19 alanine-scanning mutants were constructed and tested for their infectivity in barley and Nicotiana benthamiana. Despite its apparent normal replicative competence and CP production, the C-terminal mutant F184A produced no virions. Furthermore, virion-forming C-terminal mutants P178A and D182A failed to move from cell to cell in both plant species, and mutants D181A and V187A showed host-specific movement. These results indicate that the C-terminal region of CP plays some important roles in virus movement and encapsidation. The specificity of certain mutations for viral movement in two different plant species is evidence for the involvement of host-specific factors.

scholarly journals The charged residues in the surface-exposed C-terminus of the Soybean mosaic virus coat protein are critical for cell-to-cell movement

Virology ◽  
2013 ◽  
Vol 446 (1-2) ◽  
pp. 95-101 ◽  
Author(s):  
Jang-Kyun Seo ◽  
Mi Sa Vo Phan ◽  
Sung-Hwan Kang ◽  
Hong-Soo Choi ◽  
Kook-Hyung Kim
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Soybean Mosaic Virus ◽  
Cell Movement ◽  
Virus Coat Protein ◽  
C Terminus ◽  
Charged Residues ◽  
Virus Coat
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