Plant virus movement protein dynamics probed with a GFP-protein fusion.

A genetic fusion between the gene encoding green fluorescent protein (GFP) from the jellyfish Aequorea victoria, with that of the Ob-tobamovirus movement protein (MP) resulted in the expression of a fluorescent fusion protein (MP::GFP) that was fully biologically active in mediating the cell-to-cell spread of the Ob-virus. The MP::GFP fusion was used to follow in planta the subcellular trafficking of MP. GFP-tagged MP was transiently expressed and found to be associated with several subcellular compartments and structures including trans-wall structures, presumably plasmodesmata, and filament structures. The MP::GFP fusion can be used to monitor MP association with host proteins and structures, and for the isolation of interacting host components.