scholarly journals The conserved aromatic residue W 122 is a determinant of potyviral coat protein stability, replication, and cell‐to‐cell movement in plants

2020 ◽  
Author(s):  
Zhi‐Yong Yan ◽  
De‐Jie Cheng ◽  
Ling‐Zhi Liu ◽  
Chao Geng ◽  
Yan‐Ping Tian ◽  
...  
Keyword(s):  
Coat Protein ◽  
Protein Stability ◽  
Cell Movement ◽  
Aromatic Residue

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 Compatibility of the movement protein and the coat protein of cucumoviruses is required for cell-to-cell movement

2004 ◽  
Vol 85 (4) ◽  
pp. 1039-1048 ◽  
Author(s):  
Katalin Salánki ◽  
Ákos Gellért ◽  
Emese Huppert ◽  
Gábor Náray-Szabó ◽  
Ervin Balázs
Keyword(s):  
Coat Protein ◽  
Movement Protein ◽  
Point Mutations ◽  
Cell Movement ◽  
Virus Movement ◽  
Tomato Aspermy Virus ◽  
Sequence Encoding ◽  
Surface Electrostatic Potential ◽  
Test Plants ◽  
Insight Into

For the cell-to-cell movement of cucumoviruses both the movement protein (MP) and the coat protein (CP) are required. These are not reversibly exchangeable between Cucumber mosaic virus (CMV) and Tomato aspermy virus (TAV). The MP of CMV is able to function with the TAV CP (chimera RT), but TAV MP is unable to promote the cell-to-cell movement in the presence of CMV CP (chimera TR). To gain further insight into the non-infectious nature of the TR recombinant, RNA 3 chimeras were constructed with recombinant MPs and CPs. The chimeric MP and one of the CP recombinants were infectious. The other recombinant CP enabled virus movement only after the introduction of two point mutations (Glu→Lys and Lys→Arg at aa 62 and 65, respectively). The mutations served to correct the CP surface electrostatic potential that was altered by the recombination. The infectivity of the TR virus on different test plants was restored by replacing the sequence encoding the C-terminal 29 aa of the MP with the corresponding sequence of the CMV MP gene or by exchanging the sequence encoding the C-terminal 15 aa of the CP with the same region of TAV. The analysis of the recombinant clones suggests a requirement for compatibility between the C-terminal 29 aa of the MP and the C-terminal two-thirds of the CP for cell-to-cell movement of cucumoviruses.

Viral coat protein is targeted to, but does not gate, plasmodesmata during cell-to-cell movement of potato virus X

1996 ◽  
Vol 10 (5) ◽  
pp. 805-813 ◽  
Author(s):  
K.J. Oparka ◽  
A.G. Roberts ◽  
I.M. Roberts ◽  
D.A.M. Prior ◽  
S. Cruz
Keyword(s):  
Coat Protein ◽  
Potato Virus ◽  
Cell Movement ◽  
Potato Virus X ◽  
Viral Coat Protein ◽  
Viral Coat

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 Reciprocal function of movement proteins and complementation of long-distance movement of Cymbidium mosaic virus RNA by Odontoglossum ringspot virus coat protein

2005 ◽  
Vol 86 (5) ◽  
pp. 1543-1553 ◽  
Author(s):  
Prabha Ajjikuttira ◽  
Chiang-Shiong Loh ◽  
Sek-Man Wong
Keyword(s):  
Coat Protein ◽  
Transgenic Plants ◽  
Mosaic Virus ◽  
Cell Movement ◽  
Ringspot Virus ◽  
Deficient Mutant ◽  
Long Distance ◽  
Cymbidium Mosaic Virus ◽  
Odontoglossum Ringspot Virus ◽  
Long Distance Movement

Complementation of movement and coat proteins of the orchid-infecting potexvirus Cymbidium mosaic virus (CymMV) and tobamovirus Odontoglossum ringspot virus (ORSV) was investigated. Nicotiana benthamiana, which is susceptible to both CymMV and ORSV, was used as a model system. Four transgenic lines, each harbouring one of the movement protein (MP) or coat protein (CP) genes of CymMV or ORSV, were constructed. The MP of CymMV consists of three overlapping open reading frames, together called the triple-gene block (TGB). CymMV and ORSV mutants, each carrying an inactivated MP or CP, were generated from the respective biologically active full-length cDNA clones. Complementation was studied by infecting transgenic plants with in vitro transcripts generated from these mutants. The cell-to-cell movement of a movement-deficient CymMV was restored in transgenic plants carrying the ORSV MP transgene. Similarly, CymMV TGB1 transgenic plants were able to rescue the cell-to-cell movement of a movement-deficient ORSV mutant. ORSV CP transgenic plants supported systemic movement of a CymMV CP-deficient mutant. However, in these plants, neither encapsidation of CymMV RNA with ORSV CP nor CymMV CP expression was detected. Long-distance movement of an ORSV CP-deficient mutant was not supported by CymMV CP. The complementation of MPs and CPs of CymMV and ORSV facilitates movement of these viruses in plants, except for long-distance movement of ORSV RNA by CymMV CP.

scholarly journals Maintenance of coat protein N-terminal net charge and not primary sequence is essential for zucchini yellow mosaic virus systemic infectivity

2004 ◽  
Vol 85 (11) ◽  
pp. 3421-3430 ◽  
Author(s):  
Boaz Kimalov ◽  
Amit Gal-On ◽  
Ran Stav ◽  
Eduard Belausov ◽  
Tzahi Arazi
Keyword(s):  
Coat Protein ◽  
Mosaic Virus ◽  
Zucchini Yellow Mosaic Virus ◽  
Cell Movement ◽  
Yellow Mosaic Virus ◽  
Virus Infectivity ◽  
Amino Acid Residues ◽  
Primary Sequence ◽  
Net Charge ◽  
Truncation Mutant

Zucchini yellow mosaic virus (ZYMV) surface exposed coat protein (CP) N-terminal domain (Nt) is 43 aa long and contains an equal number of positively and negatively charged amino acid residues (CP-Nt net charge=0). A ZYMV-AGII truncation mutant lacking the first 20 aa of its CP-Nt (AGII-CPΔ20; CP-Nt net charge=+2) was found to be systemically non-infectious even though AGII mutants harbouring larger CP-Nt deletions were previously demonstrated to be fully infectious. Nevertheless, AGII-CPΔ20 infectivity was restored by fusion to its CP-Nt two Asp residues or a negatively charged Myc peptide, both predicted to neutralize CP-Nt net positive charge. To evaluate further the significance of CP-Nt net charge for AGII infectivity, a series of CP-Nt net charge mutants was generated and analysed for systemic infectivity of squash plants. AGII-CPKKK harbouring a CP-Nt amino fusion of three Lys residues (CP-Nt net charge=+3) was not systemically infectious. Addition of up to four Asp residues to CP-Nt did not abolish virus infectivity, although certain mutants were genetically unstable and had delayed infectivity. Addition of five negatively charged residues abolished infectivity (AGII-CPDDDDD; CP-Nt net charge=−5) even though a recombinant CPDDDDD could assemble into potyviral-like particle in bacteria. Neutralization of CP-Nt net charge by fusing Asp or Lys residues recovered infectivity of AGII-CPKKK and AGII-CPDDDDD. GFP-tagging of these mutants has demonstrated that both viruses have defective cell-to-cell movement. Together, these findings suggest that maintenance of CP-Nt net charge and not primary sequence is essential for ZYMV infectivity.

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.

scholarly journals Cell-to-Cell Movement of Potexviruses: Evidence for a Ribonucleoprotein Complex Involving the Coat Protein and First Triple Gene Block Protein

2000 ◽  
Vol 13 (9) ◽  
pp. 962-974 ◽  
Author(s):  
Tony J. Lough ◽  
Natalie E. Netzler ◽  
Sarah J. Emerson ◽  
Paul Sutherland ◽  
Fiona Carr ◽  
...  
Keyword(s):  
Coat Protein ◽  
Intracellular Transport ◽  
Microprojectile Bombardment ◽  
Triple Gene Block ◽  
Cell Movement ◽  
Limiting Factor ◽  
Ribonucleoprotein Complex ◽  
Gene Block ◽  
Cellular Machinery ◽  
Mode Of Transport

The triple gene block proteins (TGBp1-3) and coat protein (CP) of potexviruses are required for cell-to-cell movement. Separate models have been proposed for inter-cellular movement of two of these viruses, transport of intact virions, or a ribonucleoprotein complex (RNP) comprising genomic RNA, TGBp1, and the CP. At issue therefore, is the form(s) in which RNA transport occurs and the roles of TGBp1-3 and the CP in movement. Evidence is presented that, based on microprojectile bombardment studies, TGBp1 and the CP, but not TGBp2 or TGBp3, are co-translocated between cells with viral RNA. In addition, cell-to-cell movement and encapsidation functions of the CP were shown to be separable, and the rate-limiting factor of potexvirus movement was shown not to be virion accumulation, but rather, the presence of TGBp1-3 and the CP in the infected cell. These findings are consistent with a common mode of transport for potex-viruses, involving a non-virion RNP, and show that TGBp1 is the movement protein, whereas TGBp2 and TGBp3 are either involved in intracellular transport or interact with the cellular machinery/docking sites at the plasmodesmata.

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