The KSHV latency-associated nuclear antigen: a multifunctional protein

Kaposi's sarcoma(KS)-associated herpes virus (KSHV) or human herpesvirus 8 (HHV-8) is highly associated with KS, primary effusion lymphoma (PEL), and multicentric Castleman's disease, an aggressive lymphoproliferative disorder (1-3). Most tumor cells are latently infected with KSHV in which a small subset of viral genes are expressed (4-6). Of these latently expressed genes, the latency-associated nuclear antigen (LANA1, LNA, or LNA1) is the only protein consistently shown to be highly expressed by in situ hybridization and immunohistochemistry (7-10). In the past few years multiple functions have been demonstrated for LANA1. Here we review LANA1's roles in KSHV infection. Topics discussed include LANA1's roles in episome persistence, regulation of transcription and interaction with cellular proteins.