Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection
Kim, Sang Hyon, MacFarlane, Stuart, Kalinina, Natalia O., Rakitina, Daria V., Ryabov, Eugene V., Gillespie, Trudi, Haupt, Sophie, Brown, John W. S. and Taliansky, Michael. (2007) Interaction of a plant virus-encoded protein with the major nucleolar protein fibrillarin is required for systemic virus infection. Proceedings of the National Academy of Sciences of the United States of America, Vol.104 (No.26). pp. 11115-11120. ISSN 0027-8424Full text not available from this repository.
Official URL: http://dx.doi.org/10.1073/pnas.0704632104
The nucleolus and specific nucleolar proteins are involved in the life cycles of some plant and animal viruses, but the functions of these proteins and of nucleolar trafficking in virus infections are largely unknown. The ORF3 protein of the plant virus, groundnut rosette virus (an umbravirus), has been shown to cycle through the nucleus, passing through Cajal bodies to the nucleolus and then exiting back into the cytoplasm. This journey is absolutely required for the formation of viral ribonucleoprotein particles (RNPs) that, themselves, are essential for the spread of the virus to noninoculated leaves of the shoot tip. Here, we show that these processes rely on the interaction of the ORF3 protein with fibrillarin, a major nucleolar protein. Silencing of the fibrillarin gene prevents long-distance movement of groundnut rosette virus but does not affect viral replication or cell-to-cell movement. Repressing fibrillarin production also localizes the ORF3 protein to multiple Cajal body-like aggregates that fail to fuse with the nucleolus. Umbraviral ORF3 protein and fibrillarin interact in vitro and, when mixed with umbravirus RNA, form an RNP complex. This complex has a filamentous structure with some regular helical features, resembling the RNP complex formed in vivo during umbravirus infection. The filaments formed in vitro are infectious when inoculated to plants, and their infectivity is resistant to RNase. These results demonstrate previously undescribed functions for fibrillarin as an essential component of translocatable viral RNPs and may have implications for other plant and animal viruses that interact with the nucleolus.
|Item Type:||Journal Article|
|Divisions:||Faculty of Science > Life Sciences (2010- ) > Warwick HRI (2004-2010)|
|Journal or Publication Title:||Proceedings of the National Academy of Sciences of the United States of America|
|Publisher:||National Academy of Sciences|
|Official Date:||26 June 2007|
|Number of Pages:||6|
|Page Range:||pp. 11115-11120|
|Access rights to Published version:||Restricted or Subscription Access|
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