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  • The EMBO Journal (2007) 26, 2169 - 2179
  • doi:10.1038/sj.emboj.7601674

Published online: 5 April 2007

Cajal bodies and the nucleolus are required for a plant virus systemic infection

Sang Hyon Kim1, Eugene V Ryabov2, Natalia O Kalinina1,3, Daria V Rakitina1,3, Trudi Gillespie1, Stuart MacFarlane1, Sophie Haupt4, John WS Brown1 and Michael Taliansky1

  1. Scottish Crop Research Institute, Invergowrie, Dundee, UK
  2. HRI, University of Warwick, Wellesbourne, Warwick, UK
  3. AN Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, Russia
  4. School of Life Sciences, University of Dundee, Dundee, UK

Correspondence to:

Michael Taliansky, Plant Pathology, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK. Tel.: +44 1382 562731; Fax: +44 1382 562426; E-mail: mtalia@scri.sari.ac.uk

Received 25 August 2006; Accepted 13 March 2007

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.

  • Keywords:

    • Cajal bodies,
    • nucleolus,
    • ribonucleoprotein particles,
    • umbravirus