Participates in the transport of viral RNA to the plasmodesmata. Is probably targeted to plasmodesmata by TGBp3, along with viral RNAs-TGBp1 (RNP complex). Can gate plasmodesmata and increase their size exclusion limit (By similarity). Interacts with movement protein TGB3. localizes to plasmodesmata or plasmodesmata-associated membrane compartments called peripheral membrane bodies (PMBs). Belongs to the virgaviridae/benyvirus TGB2 movement protein family.