Expression of the “helper component” protein of potato virus Y (PVY) inE. coli: Possible involvement of a third protease

Virus Genes ◽  
1993 ◽  
Vol 7 (2) ◽  
pp. 151-156 ◽  
Author(s):  
Yehuda Stram ◽  
Aviva Chetsrony ◽  
Hagai Karchi ◽  
Miri Karchi ◽  
Orit Edelbaum ◽  
...  
Keyword(s):  
Potato Virus ◽  
Potato Virus Y ◽  
Helper Component ◽  
Component Protein

scholarly journals Helper Component Mutations in Nonconserved Residues Associated with Aphid Transmission Efficiency of a Pepper Isolate of Potato Virus Y

1999 ◽  
Vol 89 (12) ◽  
pp. 1176-1181 ◽  
Author(s):  
César Llave ◽  
Belén Martínez ◽  
J. R. Díaz-Ruíz ◽  
D. López-Abella
Keyword(s):  
Amino Acid ◽  
Potato Virus ◽  
Potato Virus Y ◽  
Aphid Transmission ◽  
Transmission Efficiency ◽  
Binding Assays ◽  
Helper Component ◽  
Rich Domain ◽  
Pepper Isolate

The aphid transmission properties of a pepper isolate of potato virus Y belonging to the pathotype 1–2 (PVY 1–2) have been characterized. PVY 1–2 was not transmitted in plant-to-plant experiments, although purified virus particles were efficiently transmitted when supplemented with heterologous helper component (HC) of the transmissible isolate PVY 0 AT through membrane acquisition assays, indicating that its coat protein was functional in transmission. Additionally, virions of PVY 1–2 were able to bind to different HCs in in vitro binding assays. Analysis of the sequence of the PVY 1–2 HC gene and comparison with that of PVY 0 AT revealed 19 nucleotide differences, but only 2 resulted in amino acid changes, one of which induced a change of charge. Neither of these two amino acid changes occurred within the cysteine-rich domain, nor did they coincide with conserved motifs of the HC protein known to be involved in aphid transmission and which are present in all known potyvi-ruses. However, both changes are located in positions highly conserved among PVY strains. The possible role of both mutations on the activity of the PVY 1–2 HC in aphid transmission is discussed.

Virus and helper component interactions favour the transmission of recombinant potato virus Y strains

2021 ◽  
Vol 102 (6) ◽  
Author(s):  
Shaonpius Mondal ◽  
William M. Wintermantel ◽  
Stewart M. Gray
Keyword(s):  
Potato Virus ◽  
Potato Virus Y ◽  
Potato Crop ◽  
Virus Binding ◽  
Helper Component ◽  
Recombinant Strains ◽  
Homologous Virus ◽  
The Usa ◽  
Acquisition Order ◽  
Ordinary Strain

In recent years, several recombinant strains of potato virus Y, notably PVYNTN and PVYN:O have displaced the ordinary strain, PVYO, and emerged as the predominant strains affecting the USA potato crop. Previously we reported that recombinant strains were transmitted more efficiently than PVYO when they were acquired sequentially, regardless of acquisition order. In another recent study, we showed that PVYNTN binds preferentially to the aphid stylet over PVYO when aphids feed on a mixture of PVYO and PVYNTN. To understand the mechanism of this transmission bias as well as preferential virus binding, we separated virus and active helper component proteins (HC), mixed them in homologous and heterologous combinations, and then fed them to aphids using Parafilm sachets. Mixtures of PVYO HC with either PVYN:O or PVYNTN resulted in efficient transmission. PVYN:O HC also facilitated the transmission of PVYO and PVYNTN, albeit with reduced efficiency. PVYNTN HC failed to facilitate transmission of either PVYO or PVYN:O. When PVYO HC or PVYN:O HC was mixed with equal amounts of the two viruses, both viruses in all combinations were transmitted at high efficiencies. In contrast, no transmission occurred when combinations of viruses were mixed with PVYNTN HC. Further study evaluated transmission using serial dilutions of purified virus mixed with HCs. While PVYNTN HC only facilitated the transmission of the homologous virus, the HCs of PVYO and PVYN:O facilitated the transmission of all strains tested. This phenomenon has likely contributed to the increase in the recombinant strains affecting the USA potato crop.

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