Systemic invasion of plants by plant viruses depends on compatible interactions between host and virus encoded factors to facilitate genome replication, cell to cell movement via plasmodesmata and long distance transport through the vascular tissue  During these processes the plant activates different types of defense responses, while on the other hand the virus evolves mechanisms to overcome these obstacles. In this complex scenario interaction between plant and viral proteins play an essential role that will define the fate of both virus and plant, thus the importance of researching the virus host
protein protein »interactome«.

The main objective of this proposal is to gain better understanding of the protein interactions in the PVYhost plant system. To do this we will:

–Search and study interactions between PVY particles and selected heterologously expressed viral and potato plant proteins. We will use surface plasmon resonance (SPR) to search for such interactions. We will clone and express virus proteins and selected plant proteins and challenge them to interact among each other and with PVY virus particles.
-Search within plant extracts for new interaction partners. We will prepare plant extracts of different complexity and inject them over a surface of immobilized PVY particles (or selected proteins) in a SPR chip. Bound molecules will be eluted from the chip and identified with mass spectroscopy.

-Obtain protein 3D structural data. We will use crystallization and X ray diffraction together with electron microscopy for resolving 3D structure of CP and possibly other heterologously expressed viral and plant proteins involved in the PVY potato interaction.
-Optimize the production and characterization of PVY VLPs.
We will optimize the assembly of PVY CP into VLPs, purify them and test how different modifications of the CP affect the formation and stability of the VLPs. PVY VLPs will be used in SPR studies to evaluate the impact of different CP mutations on the interaction of VLP with other proteins

All the resulting data including novel interactions as well as structural data will be fed into the model of plant defence signalling using network analysis methodologies to extract novel knowledge on potato in interaction with PVY.

Project ID: J7-7248
Duration: 1.1.2016 – 31.12.2018

Financing: 100,000 eur/year