Involvement of SSRP1 in latent replication of Kaposi's sarcoma-associated herpesvirus.

TitleInvolvement of SSRP1 in latent replication of Kaposi's sarcoma-associated herpesvirus.
Publication TypeJournal Article
Year of Publication2009
AuthorsHu, J, Liu, E, Renne, R
JournalJ Virol
Date Published2009 Nov
KeywordsAnimals, Antigens, Viral, Binding Sites, Cell Line, DNA Replication, DNA, Viral, DNA-Binding Proteins, Genome, Viral, Herpesviridae Infections, Herpesvirus 8, Human, High Mobility Group Proteins, Humans, Molecular Sequence Data, Nuclear Proteins, RNA, Small Interfering, Terminal Repeat Sequences, Transcriptional Elongation Factors, Virus Latency, Virus Replication

Kaposi's sarcoma-associated herpesvirus (also named human herpesvirus 8) is a gamma-herpesvirus that undergoes both lytic and latent infection. During latent infection, two viral elements are required: latency-associated nuclear antigen (LANA), which functions as an origin binding protein, and the latent origin, which resides within the terminal repeats (TRs) of the viral genome. Previously, we identified two cis-elements within the TRs which are required for latent DNA replication: two LANA binding sites (LBS1 and LBS2 [LBS1/2]) and a GC-rich replication element (RE) upstream of LBS1/2. To further characterize the RE, we constructed a 71-bp minimal replicon (MR) and performed a detailed mutational analysis. Our data indicate that the first 8 nucleotides within the RE are critical for replication. Moreover, both the position and the distance between the RE and LBS1/2 can affect origin replication activity, suggesting that the RE may function as a loading pad for cellular proteins involved in replication. Using biotinylated DNA fragments of wild-type or mutant MRs as probes, we identified 30 proteins that preferentially bind to the origin. Among these proteins, structure-specific recognition protein 1 (SSRP1), a subunit of the FACT complex, and telomeric repeat binding factor 2 (TRF2) formed complexes with LANA at the MR region. Furthermore, the small interfering RNA-based knockdown of SSRP1, but not the dominant-negative-based knockdown of TRF2, significantly decreased the efficiency of LANA-dependent DNA replication. These results indicate that SSRP1 is a novel cellular protein involved in LANA-dependent DNA replication.

Alternate JournalJ. Virol.
PubMed ID19710137
PubMed Central IDPMC2772803
Grant ListR01 CA088763 / CA / NCI NIH HHS / United States
CA88763 / CA / NCI NIH HHS / United States