Multifunctional regulator of the expression of viral genes that mediates nuclear export of viral intronless mRNAs. This immediate early (EI) protein promotes the nuclear export of viral intronless mRNAs by interacting with mRNAs and host NXF1/TAP (By similarity). Associates in a complex with RNA, and host export factors NXF1/TAP and ALYREF; these interactions allow nuclear export of viral transcripts. Shuttles between the nucleus and the cytoplasm. Belongs to the HHV-1 ICP27 protein family.