Cajal bodies and the nucleolus are required for a plant virus systemic infection.
The nucleolus and Cajal bodies (CBs) are prominent interacting subnuclear domains involved in a number of crucial aspects of cell function. Certain viruses interact with these compartments but the functions of such interactions are largely uncharacterized. Here, we show that the ability of the groundnut rosette virus open reading frame (ORF) 3 protein to move viral RNA long distances through the phloem strictly depends on its interaction with CBs and the nucleolus. The ORF3 protein targets and reorganizes CBs into multiple CB-like structures and then enters the nucleolus by causing fusion of these structures with the nucleolus. The nucleolar localization of the ORF3 protein is essential for subsequent formation of viral ribonucleoprotein (RNP) particles capable of virus long-distance movement and systemic infection. We provide a model whereby the ORF3 protein utilizes trafficking pathways involving CBs to enter the nucleolus and, along with fibrillarin, exit the nucleus to form viral 'transport-competent' RNP particles in the cytoplasm.
Kim
Sang Hyon
SH
Scottish Crop Research Institute, Invergowrie, Dundee, UK.
Ryabov
Eugene V
EV
Kalinina
Natalia O
NO
Rakitina
Daria V
DV
Gillespie
Trudi
T
MacFarlane
Stuart
S
Haupt
Sophie
S
Brown
John W S
JW
Taliansky
Michael
M
D001483:Base Sequence; D002466:Cell Nucleolus / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics; D020541:Coiled Bodies / Q000378:metabolism*; D008854:Microscopy, Electron; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008969:Molecular Sequence Data; D010935:Plant Diseases / Q000821:virology*; D018515:Plant Leaves / Q000648:ultrastructure / Q000821:virology; D010942:Plant Viruses / Q000472:pathogenicity*; D021381:Protein Transport / Q000502:physiology; D012367:RNA, Viral / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014026:Nicotiana; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D002868:Chromosomal Proteins, Non-Histone; D012367:RNA, Viral; D014764:Viral Proteins; C047458:fibrillarin