Movement protein involved in the cell-to-cell and systemic transport of viral genomic DNA. Begomoviruses use 2 proteins to transport their DNA from cell to cell. The nuclear shuttle protein (NSP) shuttles it between nucleus and cytoplasm and the movement protein (MP) probably transports the DNA-NSP complex to the cell periphery and facilitates further movement across the cell wall (By similarity). Binds to dimeric supercoiled plasmid DNA. Found on ER-derived vesicles. Phosphorylated. Belongs to the begomovirus movement protein BC1 family.