title: Ribosomal protein S6 interacts with the latency-associated nuclear antigen of Kaposi's sarcoma-associated herpesvirus.
abstract: The latency-associated nuclear antigen (LANA) is central to the maintenance of Kaposi's sarcoma-associated herpesvirus (KSHV) and to the survival of KSHV-carrying tumor cells. In an effort to identify interaction partners of LANA, we purified authentic high-molecular-weight complexes of LANA by conventional chromatography followed by immunoprecipitation from the BC-3 cell line. This is the first analysis of LANA-interacting partners that is not based on forced ectopic expression of LANA. Subsequent tandem mass spectrometry (MS/MS) analysis identified many of the known LANA-interacting proteins. We confirmed LANA's interactions with histones. Three classes of proteins survived our stringent four-step purification procedure (size, heparin, anion, and immunoaffinity chromatography): two heat shock proteins (Hsp70 and Hsp96 precursor), signal recognition particle 72 (SRP72), and 10 different ribosomal proteins. These proteins are likely involved in structural interactions within LANA high-molecular-weight complexes. Here, we show that ribosomal protein S6 (RPS6) interacts with LANA. This interaction is mediated by the N-terminal domain of LANA and does not require DNA or RNA. Depletion of RPS6 from primary effusion lymphoma (PEL) cells dramatically decreases the half-life of full-length LANA. The fact that RPS6 has a well-established nuclear function beyond its role in ribosome assembly suggests that RPS6 (and by extension other ribosomal proteins) contributes to the extraordinary stability of LANA.
authors: University of North Carolina at Chapel Hill, CB 7290, 715 Mary Ellen Jones Bldg., Chapel Hill, NC 27599-7290, USA.
authors: Wuguo
authors: W
authors: Chen
authors: Dirk P
authors: DP
authors: Dittmer
mesh_terms: D000956:Antigens, Viral / Q000378:metabolism*; D002460:Cell Line; D002845:Chromatography; D019288:Herpesvirus 8, Human / Q000472:pathogenicity*; D054884:Host-Pathogen Interactions; D006801:Humans; D047468:Immunoprecipitation; D008214:Lymphocytes / Q000737:chemistry / Q000821:virology; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D025941:Protein Interaction Mapping; D055503:Protein Multimerization; D038601:Ribosomal Protein S6 / Q000378:metabolism*; D053719:Tandem Mass Spectrometry
chemical_list: D000956:Antigens, Viral; D009687:Nuclear Proteins; D038601:Ribosomal Protein S6; C109540:latency-associated nuclear antigen