Analysis of viral cis elements conferring Kaposi's sarcoma-associated herpesvirus episome partitioning and maintenance.

TitleAnalysis of viral cis elements conferring Kaposi's sarcoma-associated herpesvirus episome partitioning and maintenance.
Publication TypeJournal Article
Year of Publication2007
AuthorsSkalsky, RL, Hu, J, Renne, R
JournalJ Virol
Date Published2007 Sep
KeywordsAntigens, Viral, Binding Sites, Cell Line, Genetic Complementation Test, Genome, Viral, Herpesviridae Infections, Herpesvirus 4, Human, Herpesvirus 8, Human, Histones, Humans, Lymphocytes, Nuclear Proteins, Plasmids, Replicon, Terminal Repeat Sequences, Viral Proteins, Virus Latency, Virus Replication

Maintenance of Kaposi's sarcoma-associated herpesvirus (KSHV) episomes in latently infected cells is dependent on the latency-associated nuclear antigen (LANA). LANA binds to the viral terminal repeats (TR), leading to recruitment of cellular origin recognition complex proteins. Additionally, LANA tethers episomes to chromosomes via interactions with histones H2A and H2B (A. J. Barbera et al., Science 311:856-861, 2006). Despite these molecular details, less is known about how episomes are established after de novo infection. To address this, we measured short-term retention rates of green fluorescent protein-expressing replicons in proliferating lymphoid cells. In the absence of antibiotic selection, LANA significantly reduced the loss rate of TR-containing replicons. Additionally, we found that LANA can support long-term stability of KSHV replicons for more than 2 months under nonselective conditions. Analysis of cis elements within TR that confer episome replication and partitioning revealed that these activities can occur independently, and furthermore, both events contribute to episome stability. We found that replication-deficient plasmids containing LANA binding sites (LBS1/2) exhibited measurable retention rates in the presence of LANA. To confirm these observations, we uncoupled KSHV replication and partitioning by constructing hybrid origins containing the Epstein-Barr virus (EBV) dyad symmetry for plasmid replication and KSHV LBS1/2. We demonstrate that multiple LBS1/2 function in a manner analogous to that of the EBV family of repeats by forming an array of LANA binding sites for partitioning of KSHV genomes. Our data suggest that the efficiency with which KSHV establishes latency is dependent on multiple LANA activities, which stabilize viral genomes early after de novo infection.

Alternate JournalJ Virol
PubMed ID17626102
PubMed Central IDPMC2045406
Grant List5T32 CA 009126-30 / CA / NCI NIH HHS / United States
R21 CA097939 / CA / NCI NIH HHS / United States
CA 097939 / CA / NCI NIH HHS / United States
T32 CA009126 / CA / NCI NIH HHS / United States
R01 CA088763 / CA / NCI NIH HHS / United States
CA 88763 / CA / NCI NIH HHS / United States