Plays a role in the transport and release of virions form the host cytoplasm to the extracellular space. Relocalizes host NEDD4, a cytosolic E3 ligase, to cytoplasmic vesicles. Interacts with host ITCH; this interaction induces ubiquitination and degradation of ITCH (PubMed:20682038). Interacts with host NEDD4; this interaction increases NEDD4 ubiquitination (PubMed:18353951). Interacts with UL11 (PubMed:16604447). If expressed alone, is predominantly present in host trans-Golgi network (TGN) and partially in Golgi complex and early endosomes. Late-budding domains (L domains) are short sequence motifs essential for viral particle budding. They recruit proteins of the host ESCRT machinery (Endosomal Sorting Complex Required for Transport) or ESCRT-associated proteins. UL56 contains three L domains: the PPXY motifs which are involved in the interaction with ITCH, a member of the NEDD4 family. Belongs to the herpesviridae UL56 family.