Plays a role in the translocation of the P40 subunit of host Arp2/3 to the nucleus. The robust nuclear accumulation of Arp2/3 induces nuclear actin polymerization to assist in virus replication. Mechanistically, subverts the host CRM1-dependent nuclear export pathway leading to Arp2/3 acumulation in the host nucleus. Interacts with host proteins P40, P34 ands P20.