scholarly journals Plant Translation Elongation Factor 1Bβ Facilitates Potato Virus X (PVX) Infection and Interacts with PVX Triple Gene Block Protein 1

PLoS ONE ◽  
2015 ◽  
Vol 10 (5) ◽  
pp. e0128014 ◽  
Author(s):  
JeeNa Hwang ◽  
Seonhee Lee ◽  
Joung-Ho Lee ◽  
Won-Hee Kang ◽  
Jin-Ho Kang ◽  
...  
1991 ◽  
Vol 72 (8) ◽  
pp. 2039-2042 ◽  
Author(s):  
S. Yu. Morozov ◽  
N. A. Miroshnichenko ◽  
A. G. Solovyev ◽  
O. N. Fedorkin ◽  
D. A. Zelenina ◽  
...  

2001 ◽  
Vol 14 (10) ◽  
pp. 1158-1167 ◽  
Author(s):  
Atsushi Tamai ◽  
Tetsuo Meshi

Potato virus X (PVX) requires three proteins, p25, p12, and p8, encoded by the triple gene block plus the coat protein (CP) for cell-to-cell movement. When each of these proteins was co-expressed with a cytosolic green fluorescent protein (GFP) in the epidermal cells of Nicotiana benthamiana by the microprojectile bombardment-mediated gene delivery method, only p12 enhanced diffusion of co-expressed GFP, indicating an ability to alter plasmodesmal permeability. p25, p12, and CP, expressed transiently in the initially infected cells, transcomplemented the corresponding movement-defective mutants to spread through two or more cell boundaries. Thus, these proteins probably move from cell to cell with the genomic RNA. In contrast, p8 only functioned intracellularly and was not absolutely required for cell-to-cell movement. Since overexpression of p12 overcame the p8 deficiency, p8 appears to facilitate the functioning of p12, presumably by mediating its intracellular trafficking. Considering the likelihood that p12 and p8 are membrane proteins, it is suggested that intercellular as well as intracellular movement of PVX involves a membrane-mediated process.


1998 ◽  
Vol 72 (10) ◽  
pp. 8316-8320 ◽  
Author(s):  
Jeanmarie Verchot ◽  
Susan M. Angell ◽  
David C. Baulcombe

ABSTRACT The 25-kilodalton (25K), 12K, and 8K movement proteins of potato virus X are derived from overlapping open reading frames (ORFs). Using an in vivo complementation assay, we have shown that the 25K protein is expressed from a functionally monocistronic mRNA, whereas the 12K and 8K proteins are from a bicistronic mRNA. Translation of the 8K ORF is by leaky ribosome scanning through the 12K ORF.


2009 ◽  
Vol 83 (15) ◽  
pp. 7761-7769 ◽  
Author(s):  
Heidrun-Katharina Draghici ◽  
Mark Varrelmann

ABSTRACT Recombination in RNA viruses, one of the main factors contributing to their genetic variability and evolution, is a widespread phenomenon. In this study, an in vivo assay to characterize RNA recombination in potato virus X (PVX), under high selection pressure, was established. Agrobacterium tumefaciens was used to express in Nicotiana benthamiana leaf tissue both a PVX isolate labeled with green fluorescent protein (GFP) containing a coat protein deletion mutation (ΔCP) and a transcript encoding a functional coat protein +3′-ntr. Coexpression of the constructs led to virus movement and systemic infection; reconstituted recombinants were observed in 92% of inoculated plants. Similar results were obtained using particle bombardment, demonstrating that recombination mediated by A. tumefaciens was not responsible for the occurrence of PXC recombinants. The speed of recombination could be estimated by agroinfection of two PVX mutants lacking the 3′ and 5′ halves of the genome, respectively, with an overlap in the triple gene block 1 gene, allowing GFP expression only in the case of recombination. Ten different pentapeptide insertion scanning replicase mutants with replication abilities comparable to wild-type virus were applied in the different recombination assays. Two neighboring mutants affecting the linker between the methyltransferase and helicase domains were shown to be strongly debilitated in their ability to recombine. The possible functional separation of replication and recombination in the replicase molecule supports the model that RNA recombination represents a distinct function of this protein, although the underlying mechanism still needs to be investigated.


FEBS Journal ◽  
2009 ◽  
Vol 276 (23) ◽  
pp. 7006-7015 ◽  
Author(s):  
Elena Lukashina ◽  
Gennady Badun ◽  
Natalia Fedorova ◽  
Alexander Ksenofontov ◽  
Maria Nemykh ◽  
...  

2008 ◽  
Vol 21 (8) ◽  
pp. 1106-1117 ◽  
Author(s):  
Tefera Mekuria ◽  
Devinka Bamunusinghe ◽  
Mark Payton ◽  
Jeanmarie Verchot-Lubicz

To determine the requirements for viral proteins exiting the phloem, transgenic plants expressing green fluorescent protein (GFP) fused to the Potato virus X (PVX) triple gene block (TGB)p1 and coat protein (CP) genes were prepared. The fused genes were transgenically expressed from the companion cell (CC)-specific Commelina yellow mottle virus (CoYMV) promoter. Transgenic plants were selected for evidence of GFP fluorescence in CC and sieve elements (SE) and proteins were determined to be phloem mobile based on their ability to translocate across a graft union into nontransgenic scions. Petioles and leaves were analyzed to determine the requirements for phloem unloading of the fluorescence proteins. In petioles, fluorescence spread throughout the photosynthetic vascular cells (chlorenchyma) but did not move into the cortex, indicating a specific barrier to proteins exiting the vasculature. In leaves, fluorescence was mainly restricted to the veins. However, in virus-infected plants or leaves treated with a cocktail of proteasome inhibitors, fluorescence spread into leaf mesophyll cells. These data indicate that PVX contributes factors which enable specific unloading of cognate viral proteins and that proteolysis may play a role in limiting proteins in the phloem and surrounding chlorenchyma.


2007 ◽  
Vol 153 (1) ◽  
pp. 223-226 ◽  
Author(s):  
M. Bruun-Rasmussen ◽  
C. T. Madsen ◽  
E. Johansen ◽  
M. Albrechtsen

2003 ◽  
Vol 16 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Ingela Fridborg ◽  
Jef Grainger ◽  
Anthony Page ◽  
Mark Coleman ◽  
Kim Findlay ◽  
...  

The cell-to-cell movement of Potato virus X (PVX) requires four virus-encoded proteins, the triple gene block (TGB) proteins (TGB25K, TGB12K, and TGB8K) and the coat protein. TGB12K increases the plasmodesmal size exclusion limit (SEL) and may, therefore, interact directly with components of the cell wall or with plant proteins associated with bringing about this change. A yeast two-hybrid screen using TGB12K as bait identified three TGB12K-interacting proteins (TIP1, TIP2, and TIP3). All three TIPs interacted specifically with TGB12K but not with TGB25K or TGB8K. Similarly, all three TIPs interacted with β-1,3-glucanase, the enzyme that may regulate plasmodesmal SEL through callose degradation. Sequence analyses revealed that the TIPs encode very similar proteins and that TIP1 corresponds to the tobacco ankyrin repeat-containing protein HBP1. A TIP1::GFP fusion protein localized to the cytoplasm. Coexpression of this fusion protein with TGB12K induced cellular changes manifested as deposits of additional cytoplasm at the cell periphery. This work reports a direct link between a viral movement protein required to increase plasmodesmal SEL and a host factor that has been implicated as a key regulator of plasmodesmal SEL. We propose that the TIPs are susceptibility factors that modulate the plasmodesmal SEL.


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