Previous genome-wide screens identified > 100 host genes affecting tombusvirus replication using yeast model host. One of those factors was Nsr1p (nucleolin), which is an abundant RNA-binding shuttle protein involved in rRNA maturation and ribosome assembly. We find that overexpression of Nsr1p in yeast or in Nicotiana benthamiana inhibited the accumulation of tombusvirus RNA by ∼10-fold. Regulated overexpression of Nsr1p revealed that Nsr1p should be present at the beginning of viral replication for efficient inhibition, suggesting that Nsr1p inhibits an early step in the replication process. In vitro experiments revealed that Nsr1p binds preferably to the 3′ UTR in the viral RNA. The purified recombinant Nsr1p inhibited the in vitro replication of the viral RNA in a yeast cell-free assay when preincubated with the viral RNA before the assay. These data support the model that Nsr1p/nucleolin inhibits tombusvirus replication by interfering with the recruitment of the viral RNA for replication.
|Number of pages||11|
|State||Published - Jan 5 2010|
Bibliographical noteFunding Information:
The authors thank Drs. Judit Pogany and Daniel Barajas. The authors are grateful to Dr. K. Nakamura for sharing plasmid pGWB5 and to Dr. M. Goodin for the At-Fibrillarin1-RFP transgenic N. benthamiana and anti-GFP and anti-chicken antibodies. This work was supported by the National Science Foundation (IOB-0517218), NIH-NIAID 5R21AI072170-02, and the Kentucky Tobacco Research and Development Center.
- Host factor
- Nucleolin, Nicotiana benthamiana
- Tomato bushy stunt virus
ASJC Scopus subject areas