Plays a role in virus cell-to-cell and plant-to-plant transmission. Interacts with virion icosahedral capsid and movement protein, thereby facilitating virion cell-to-cell transmission throug plasmodesmata opned by viral movement protein. Alsointeracts with aphid transmission factor, attaching the virion to aphid stylet when the animal feeds on an virus infected plant. Aphid saliva may later detach the virion, inducing release of infectious particles when the animal feeds on a new plant (By similarity).