Plays a crucial role for reactivation of the virus from latency, early viral gene expression and virus production. Modulates host signaling pathways including activation of MAP kinases c-JUN-N-terminal kinase (JNK), ERK2, and NF-kappa-B resulting in the activation of AP-1 and NFAT-dependent gene expression in B-lymphocytes. When expressed in epithelial cells, induces the expression of several inflammatory and angiogenic genes. Interferes also with B-lymphocytes signaling through interaction with host LYN kinase. Interacts with host LYN; this interaction modulates B-cells signaling. Interacts with host ITSN2. Localizes to the trans-Golgi network (TGN) compartment during latency and relocalizes to the cell periphery when the lytic program is induced.