Characterization of the Minimal Replicator of Kaposi's Sarcoma-Associated Herpesvirus Latent Origin

Division of Hematology/Oncology and Department of Molecular Genetics and Microbiology, Case Western Reserve University, Cleveland, OH, USA.
Journal of Virology (Impact Factor: 4.44). 03/2005; 79(4):2637-42. DOI: 10.1128/JVI.79.4.2637-2642.2005
Source: PubMed


The latency-associated nuclear antigen (LANA) of Kaposi's sarcoma-associated herpesvirus (KSHV) binds to two sites within the 801-bp-long terminal repeat (TR) and is the only viral protein required for episomal maintenance. While two or more copies of TR are required for long-term maintenance, a single TR confers LANA-dependent origin activity on plasmid DNA. Deletion mapping revealed a 71-bp-long minimal replicator containing two distinctive sequence elements: LANA binding sites (LBS1/2) and an adjacent 29- to 32-bp-long GC-rich sequence which we termed the replication element. Furthermore, the transcription factor Sp1 can bind to TR outside the minimal replicator and contributes to TR's previously reported enhancer activity.

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Available from: Rolf Renne, Mar 04, 2014
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    • "LANA has two binding sites called LANA binding sequences (LBS) in TR and replication origin of the KSHV genome in latency (ori-P) consists of the LBS and the following 32bp GCrich segment (32GC) (Garber, Hu, and Renne, 2002; Garber et al., 2001). One of two LBS is required for the viral replication at least but it is not enough, i.e., 32GC is also required (Hu and Renne, 2005). Though it remains to be solved how the viral ori-P is determined among repeated TR sequences and how 32GC is functioning, LANA has been reported to interact with components of cellular replication machinery; origin recognition complex 1 to 6 (ORC1~ORC6) (Verma et al., 2006). "

    Herpesviridae - A Look Into This Unique Family of Viruses, 03/2012; , ISBN: 978-953-51-0186-4
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    • "This observation suggests that the KSHV genome uses cellular replication machinery so that viral DNA replication synchronizes with the cell cycle. The KSHV origin of replication in latency, called ori-P, consists of two LANA-binding sites (LBS), in which LBS1 has a higher affinity with LANA (Garber et al., 2002), and the following 32 bp GC-rich segment (termed 32GC in this manuscript) and the ori-P is in the TR region of the KSHV episome (Hu and Renne, 2005; Figure 1). LANA directly binds to LBS and supports viral DNA replication (Garber et al., 2002; Hu et al., 2002; Fejer et al., 2003; Grundhoff and Ganem, 2003). "
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    ABSTRACT: Kaposi's sarcoma-associated herpesvirus (KSHV) is thought to be an oncogenic member of the γ-herpesvirus subfamily. The virus usually establishes latency upon infection as a default infection pattern. The viral genome replicates according to the host cell cycle by recruiting the host cellular replication machinery. Among the latently expressing viral factors, LANA plays pivotal roles in viral genome replication, partitioning, and maintenance. LANA binds with two LANA-binding sites (LBS1/2) within a terminal repeat (TR) sequence and is indispensable for viral genome replication in latency. The nuclear matrix region seems to be important as a replication site, since LANA as well as cellular replication factors accumulate there and recruit the viral replication origin in latency (ori-P) by its binding activity to LBS. KSHV ori-P consists of LBS followed by a 32-bp GC-rich segment (32GC). Although it has been reported that LANA recruits cellular pre-replication complexes (pre-RC) such as origin recognition complexes (ORCs) to the ori-P through its interaction with ORCs, this mechanism does not account completely for the requirement of the 32GC. On the other hand, there are few reports about the partitioning and maintenance of the viral genome. LANA interacts with many kinds of chromosomal proteins, including Brd2/RING3, core histones, such as H2A/H2B and histone H1, and so on. The detailed molecular mechanisms by which LANA enables KSHV genome partitioning and maintenance still remain obscure. By integrating the findings reported thus far on KSHV genome replication, partitioning, and maintenance in latency, we will summarize what we know now, discuss what questions remain to be answered, and determine what needs to be done next to understand the mechanisms underlying viral replication, partitioning, and maintenance strategy.
    Frontiers in Microbiology 01/2012; 3:7. DOI:10.3389/fmicb.2012.00007 · 3.99 Impact Factor
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    • "In an attempt to identify the minimal DNA element required for replication at the TR, Hu et al. performed short-term replication assays with the deletion mutants of the TR and mapped a 71-bp unit of the TR as the minimal replicator element (Hu and Renne, 2005). This unit comprises LBS1/2 and an adjacent 29-to 32-bp-long GC-rich element referred to as replication element (RE) upstream of the LBSs (Hu and Renne, 2005). We recently identified a latent replication origin in the long unique region of the viral genome, which initiates replication independent of viral proteins in trans, suggesting that this is an autonomously replicating element in the LUR (Verma et al., 2007a). "
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    ABSTRACT: Kaposi's Sarcoma-associated Herpesvirus (KSHV), also known as human herpesvirus 8 (HHV-8), is the most recently identified human tumor virus,and is associated with the pathogenesis of Kaposi's sarcoma and two lymphoproliferative disorders known to occur frequently in AIDS patients-primary effusion lymphoma and multicentric Castleman disease. In the 15 years since its discovery, intense studies have demonstrated an etiologic role for KSHV in the development of these malignancies. Here, we review the recent advances linked to understanding KSHV latent and lytic life cycle and the molecular mechanisms of KSHV-mediated oncogenesis in terms of transformation, cell signaling, cell growth and survival, angiogenesis, immune invasion and response to microenvironmental stress, and highlight the potential therapeutic targets for blocking KSHV tumorigenesis.
    Advances in Virus Research 01/2010; 78:87-142. DOI:10.1016/B978-0-12-385032-4.00003-3 · 4.57 Impact Factor
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