Multifunctional protein that plays a role in the replication and long-term persistence of the viral episomal genome in dividing cells. Binds to mitotic chromosomes via its N-terminal region and to a 16-bp imperfect palindrome within the origin of replication (oriP) located in the viral terminal repeat (TR) through its C-terminal. Tethers viral episomes to chromosomes during mitosis. Plays a critical role in the shutdown of lytic gene expression during the early stage of infection by interacting with host TRIM28. Also plays a role in the repression of host NF-kappa-B activity upon TNF-alpha stimulation by promoting the proteasomal degradation of host RELA (PubMed:21697472). Homooligomer (PubMed:25947153). Interacts with host BRD2 (PubMed:16227282). Interacts with host RELA, ELOB, ELOC and CUL5; these interactions induce the proteasomal degradation of host RELA (PubMed:21697472). Interacts with host TRIM28 and NFE2L2/NRF2; these interactions are essential for the shutdown of lytic gene expression during the early stage of infection (PubMed:24741090, PubMed:25995248). Interacts (via N-terminus) with host histones H2A and H2B; these interactions are essential to dock LANA1 onto chromosomes (PubMed:16469929). Interacts with host BUB1 and PCNA (PubMed:26223641). Interacts with host NAP1L1; this interaction is required for LANA1-dependent DNA replication (PubMed:27599637). Colocalizes with viral episomes on host chromosomes.