A Role for the Internal Repeat of the Kaposi's Sarcoma-Associated Herpesvirus Latent Nuclear Antigen in the Persistence of an Episomal Viral Genome

The latent nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV) is required for the replication and partitioning of latent viral genomes. It contains an extended internal repeat (IR) region whose function is only incompletely understood. We constructed KSHV genomes lacking either LANA (KSHV-Delta LANA) or the IR region of LANA (KSHV-LANA Delta 329-931). Although still capable of replicating a plasmid containing a latent origin of replication, LANA Delta 329-931 does not support the establishment of stable cell lines containing a KSHV genome. These findings suggest a role for the LANA IR in KSHV episomal maintenance without its being required for replication.