Transports viral genome to neighboring plant cells directly through plasmosdesmata, without any budding. The movement protein allows efficient cell to cell propagation, by bypassing the host cell wall barrier. Acts by forming tubules structures that increase the size exclusion limit (SEL) of plasmodesmata, thereby allowing viral ribonucleocapsids to spread directly to neighboring cells. Homotrimer, through the coiled-coil domain. Interacts with VAP. May interact (via N-terminus) with host prenylated Rab acceptor protein 1D (PRA1D). Assembles in tubules that are embedded within modified plasmodesmata. Belongs to the caulimoviridae movement protein family.