Replication of Tomato bushy stunt virus (TBSV) RNA takes place on the cytosolic membrane surface of peroxisomes in plants and in yeast, a model host. To identify the host proteins involved in assisting the peroxisomal localization of the tombusvirus p33 replication protein, we tested if p33 could bind directly to yeast proteins involved in peroxisomal transport in vitro. This work has led to the demonstration of Pex19p-p33 interaction via pull-down and co-purification experiments. Pex19p was also detected in the tombusvirus replicase after protein cross-linking, suggesting that Pex19p transiently binds to the replicase as could be expected from a transporter. To validate the importance of Pex19p-p33 interaction in TBSV replication in yeast, we re-targeted Pex19p to the mitochondria, which resulted in the re-distribution of a large fraction of p33 to the mitochondria. The expression of the mitochondrial-targeted Pex19p inhibited TBSV RNA accumulation by 2-4-fold in vivo and reduced the in vitro activity of the tombusvirus replicase by 80%. These data support the model that Pex19p is a cellular transporter for localization of p33 replication protein to the host peroxisomal membranes.
|Number of pages||12|
|State||Published - Sep 30 2008|
Bibliographical noteFunding Information:
The authors thank Dr. Judit Pogany and Kai Xu for valuable comments. Dr. Robert Wang for his help with Confocal laser microscopy and Dr. Li for his help with the co-purification experiments. The authors are grateful to Drs. R. Sopko and B. Andrews, University of Toronto, Ontario, Canada for the yeast GST-ORF over-expression library, to Dr. R. Erdmann, Bochum, Germany for the anti-Pex19 antibody. This work was supported by the National Science Foundation (IOB-0517218), and the Kentucky Tobacco Research and Development Center. KBP was also supported by Philip Morris fellowship.
- Dominant negative
- Host-virus interaction
- RNA virus
- Tomato bushy stunt virus
ASJC Scopus subject areas