Over-expression of putative transcriptional coactivator KELP interferes with Tomato mosaic virus cell-to-cell movement.
Tomato mosaic virus (ToMV) encodes a movement protein (MP) that is necessary for virus cell-to-cell movement. We have demonstrated previously that KELP, a putative transcriptional coactivator of Arabidopsis thaliana, and its orthologue from Brassica campestris can bind to ToMV MP in vitro. In this study, we examined the effects of the transient over-expression of KELP on ToMV infection and the intracellular localization of MP in Nicotiana benthamiana, an experimental host of the virus. In co-bombardment experiments, the over-expression of KELP inhibited virus cell-to-cell movement. The N-terminal half of KELP (KELPdC), which had been shown to bind to MP, was sufficient for inhibition. Furthermore, the over-expression of KELP and KELPdC, both of which were co-localized with ToMV MP, led to a reduction in the plasmodesmal association of MP. In the absence of MP expression, KELP was localized in the nucleus and the cytoplasm by the localization signal in its N-terminal half. It was also shown that ToMV amplified normally in protoplasts prepared from leaf tissue that expressed KELP transiently. These results indicate that over-expressed KELP interacts with MP in vivo and exerts an inhibitory effect on MP function for virus cell-to-cell movement, but not on virus amplification in individual cells.
Sasaki
Nobumitsu
N
Gene Research Centre, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509, Japan.
Ogata
Takuya
T
Deguchi
Masakazu
M
Nagai
Shoko
S
Tamai
Atsushi
A
Meshi
Tetsuo
T
Kawakami
Shigeki
S
Watanabe
Yuichiro
Y
Matsushita
Yasuhiko
Y
Nyunoya
Hiroshi
H
D029681:Arabidopsis Proteins / Q000378:metabolism*; D036022:Capsid Proteins / Q000378:metabolism; D042541:Intracellular Space / Q000378:metabolism / Q000821:virology; D053830:Plant Viral Movement Proteins / Q000378:metabolism; D010942:Plant Viruses / Q000502:physiology*; D021381:Protein Transport; D011523:Protoplasts / Q000821:virology; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D014026:Nicotiana / Q000166:cytology* / Q000821:virology*; D015534:Trans-Activators / Q000378:metabolism*; D014779:Virus Replication
D029681:Arabidopsis Proteins; D036022:Capsid Proteins; C113673:KELP protein, Arabidopsis; D053830:Plant Viral Movement Proteins; D011993:Recombinant Fusion Proteins; D015534:Trans-Activators