Plays a role in the activation of the host NF-kappa-B pathway by interacting with and thus activating the component MAP3K7. Interacts with host KRT18 (PubMed:11765921). Interacts with host MAP3K7; this interaction induces host NF-kappa-B pathway (PubMed:28827540). Found in association with the nuclear matrix of infected cells. Belongs to the herpesviridae HHV-1 US2 protein family.