Molecular interactions of a plant virus genome with virus-coded and host cell proteins involved in intercellular virus transport: high-resolution imaging of protein-protein and protein-RNA complexes

Project Co-ordinator Prof. Michael Taliansky

General description

Virus-encoded movement proteins (MP) are essential for cell-to-cell translocation of plant viral genomes. It is widely believed that intra- and intercellular trafficking of viral MP and transport RNP non-virion (MP-RNA) or virion (CP-RNA) complexes depend on their interactions with cellular receptors, the MP-binding proteins (MPBPs). The proposed interdisciplinary research will identify and characterize the architecture and structure of cellular MPBPs complexes with viral MPs and transport RNP complexes by atomic force microscopy (AFM) and Biacore system, and elucidating the changes in the structure of complexes following phosphorylation in relation to their functions.

These include:

  • Complexes formed by the MPs and host-plant-coded MPBPs.
  • Purified MPBPs, in particular, the pectin methylesterase (PME).
  • Complexes formed by MPBPs and "MP-RNA" ribonucleoproteins (RNPs).
  • Nontranslatable non-virion "MP-RNA" or virion "CP-RNA" RNP-complexes, and the same RNPs converted into a translatable form after phosphorylation of the MP (or CP).
  • Native and phosphorylated viral genome-linked protein (VPg) exposed on the surface of the potato virus A. A putative complex formed by the virion VPg with cellular proteins.

Research Programme

Task 1. To image and measure by AFM the structure of cellular MPBPs, their complexes with viral MPs and nucleoprotein transport complexes (MP-RNA and CP-RNA) formed in vitro.

Task 2. To study by AFM the structural changes induced upon translational activation of: (i) TMV MP-RNA and encapsidated PVX RNA by proteins phosphorylation; (ii) encapsidated PVX RNA by binding the TGBp1 MP molecules to one end of the virions.

Task 3. To visualize by AFM and/or by cryoelectron microscopy the location of VPg on the surface of PVA potyvirus virions and the complexes formed by the virion VPg with cellular proteins; to study the effect of VPg phosphorylation on the structure of virus particles and RNA translatability.

Task 4. The aims are to determine the rate of association and dissociation of complexes and the effects of modifications on binding strength and complex stability.

Participating teams

1. Scottish Crop Research Institute, Division of Pathology, Unit of Virology
team leader Prof. Michael Taliansky

2. University of Helsinki, Institute of Biotechnology
team leader Dr. Kristiina Makinen

3. M.V.Lomonosov Moscow State University, Plant Virology Department
team leader Prof. Josheph Atabekov

4. Advanced Technology Center
team leader Dr. Olga Kiselyova

5. Centre of Bioengineering, Laboratory of Genetic Engineering
team leader Prof. Konstantin Skryabin