Characterization of the intercellular trafficking of Tobacco mosaic cirus movement protein and identification of interacting factors

• Applicant: Dr. Katrin Brandner
• Subject Area: Plant Genetics and Genomics
• Term: Funded in 2006
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 25903731

Plant cells communicate via plasmodesmata (PD), channels in the plant cell wall that provide cytoplasmic continuity between adjoining cells. With connected phloem in the plant veins and stems, the system of PD represents a cell-cell and systemic communication network that controls the trafficking of a variety of molecules, including regulatory proteins and RNA molecules that play a role in plant development and defence against pathogens. Plant RNA viruses have adapted to this communication network and encode movement proteins (MPs) that facilitate the spread of the viral RNA genome (vRNA) between cells. Thus, studying viral transport and the interaction partners of vira! movement proteins provides an excellent opportunity to investigate the intercellular communication machinery. I wish to apply biochemical studies to identify novel interaction partners of viral MP and to apply novel approaches in life cell microscopy, such as Bimolecular Fluorescence Complementation (BiFC) and photo-activatable GFP, to investigate dynamic protein:protein and protein:vRNA interactions and their trafficking in vivo. Moreover, based on previous reports indicating that the MP is degraded by the ubiquitin/26S proteasome pathway, I will apply BiFC also to investigate the formation and intracellular location of ubiquitinylated MP during infection. In essence, the proposed studies will elucidate viral host cell functions that are involved in RNA transport and therefore will allow to gain new insights in cell-cell communication and viral pathogenesis.

• DFG Programme: Research Fellowships
• International Connection: France
• Host: Professor Dr. Manfred Heinlein