scholarly journals Epstein-Barr Virus (EBV) Nuclear Antigen 1 Colocalizes with Cellular Replication Foci in the Absence of EBV Plasmids

2003 ◽  
Vol 77 (6) ◽  
pp. 3824-3831 ◽  
Author(s):  
Sayuri Ito ◽  
Kazuo Yanagi
Keyword(s):  
Epstein Barr Virus ◽  
Short Pulse ◽  
Protein A ◽  
Nuclear Antigen ◽  
Metaphase Chromosomes ◽  
Barr Virus ◽  
Replication Foci ◽  
Epstein Barr ◽  
Cellular Replication ◽  
Cellular Dna

ABSTRACT Epstein-Barr virus (EBV) EBNA-1 is the only EBV-encoded protein that is essential for the once-per-cell-cycle replication and maintenance of EBV plasmids in latently infected cells. EBNA-1 binds to the oriP region of latent EBV plasmids and cellular metaphase chromosomes. In the absence of oriP-containing plasmids, EBNA-1 was highly colocalized with cellular DNA replication foci that were identified by immunostaining S-phase cells for proliferating cell nuclear antigen and replication protein A (RP-A) in combination with DNA short pulse-labeling. For the association of EBNA-1 with the cellular replication focus areas, the EBNA-1 regions of amino acids (aa) 8 to 94 and/or aa 315 to 410, but not the RP-A-interacting carboxy-terminal region, were necessary. These results suggest a new aspect of latent virus-cell interactions.

scholarly journals Architecture of Replication Compartments Formed during Epstein-Barr Virus Lytic Replication

2005 ◽  
Vol 79 (6) ◽  
pp. 3409-3418 ◽  
Author(s):  
Tohru Daikoku ◽  
Ayumi Kudoh ◽  
Masatoshi Fujita ◽  
Yutaka Sugaya ◽  
Hiroki Isomura ◽  
...  
Keyword(s):  
Dna Replication ◽  
Viral Replication ◽  
Epstein Barr Virus ◽  
Protein A ◽  
Lytic Replication ◽  
Viral Dna ◽  
Barr Virus ◽  
Epstein Barr ◽  
Cellular Replication ◽  
Cellular Dna

ABSTRACT Epstein-Barr virus (EBV) productive DNA replication occurs at discrete sites, called replication compartments, in nuclei. In this study we performed comprehensive analyses of the architecture of the replication compartments. The BZLF1 oriLyt binding proteins showed a fine, diffuse pattern of distribution throughout the nuclei at immediate-early stages of induction and then became associated with the replicating EBV genome in the replication compartments during lytic infection. The BMRF1 polymerase (Pol) processivity factor showed a homogenous, not dot-like, distribution in the replication compartments, which completely coincided with the newly synthesized viral DNA. Inhibition of viral DNA replication with phosphonoacetic acid, a viral DNA Pol inhibitor, eliminated the DNA-bound form of the BMRF1 protein, although the protein was sufficiently expressed in the cells. These observations together with the findings that almost all abundantly expressed BMRF1 proteins existed in the DNA-bound form suggest that the BMRF1 proteins not only act at viral replication forks as Pol processive factors but also widely distribute on newly replicated EBV genomic DNA. In contrast, the BALF5 Pol catalytic protein, the BALF2 single-stranded-DNA binding protein, and the BBLF2/3 protein, a component of the helicase-primase complex, were colocalized as distinct dots distributed within replication compartments, representing viral replication factories. Whereas cellular replication factories are constructed based on nonchromatin nuclear structures and nuclear matrix, viral replication factories were easily solubilized by DNase I treatment. Thus, compared with cellular DNA replication, EBV lytic DNA replication factories would be simpler so that construction of the replication domain would be more relaxed.

Repeat arrays in cellular DNA related to the Epstein-Barr virus IR3 repeat

1985 ◽  
Vol 5 (3) ◽  
pp. 457-465
Author(s):  
M Heller ◽  
E Flemington ◽  
E Kieff ◽  
P Deininger
Keyword(s):  
Epstein Barr Virus ◽  
Tandem Repeats ◽  
Protein Domain ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Epstein Barr ◽  
Cellular Dna ◽  
The Relationship ◽  
Simple Sequence ◽  
Tandem Arrays

We isolated clones and determined the sequence of portions of mouse and human cellular DNA which cross-hybridize strongly with the IR3 repetitive region of Epstein-Barr virus. The sequences were found to be tandem arrays of a simple sequence based on the triplet GGA, very similar to the IR3 repeat. The cellular repeats have distinct differences from the viral repeat region, however, and their sequences do not appear capable of being translated into a purely glycine-plus-alanine protein domain like the portion of the Epstein-Barr nuclear antigen coded by IR3. Although the relationship between IR3 and the cellular repeats is left unclear, the cellular repeats have many interesting features. The tandem arrays are about 1 to several kilobases long, much shorter than satellite tandem repeats and larger than other interspersed, tandem repeats. Each of the repeats is a distinct variation, perhaps diverged from a common sequence, (GGA)n. This family is present in the genomes of all species tested and appears to be a ubiquitous feature of all higher eucaryotic genomes.

scholarly journals Repeat arrays in cellular DNA related to the Epstein-Barr virus IR3 repeat.

1985 ◽  
Vol 5 (3) ◽  
pp. 457-465 ◽  
Author(s):  
M Heller ◽  
E Flemington ◽  
E Kieff ◽  
P Deininger
Keyword(s):  
Epstein Barr Virus ◽  
Tandem Repeats ◽  
Protein Domain ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Epstein Barr ◽  
Cellular Dna ◽  
The Relationship ◽  
Simple Sequence ◽  
Tandem Arrays

We isolated clones and determined the sequence of portions of mouse and human cellular DNA which cross-hybridize strongly with the IR3 repetitive region of Epstein-Barr virus. The sequences were found to be tandem arrays of a simple sequence based on the triplet GGA, very similar to the IR3 repeat. The cellular repeats have distinct differences from the viral repeat region, however, and their sequences do not appear capable of being translated into a purely glycine-plus-alanine protein domain like the portion of the Epstein-Barr nuclear antigen coded by IR3. Although the relationship between IR3 and the cellular repeats is left unclear, the cellular repeats have many interesting features. The tandem arrays are about 1 to several kilobases long, much shorter than satellite tandem repeats and larger than other interspersed, tandem repeats. Each of the repeats is a distinct variation, perhaps diverged from a common sequence, (GGA)n. This family is present in the genomes of all species tested and appears to be a ubiquitous feature of all higher eucaryotic genomes.

scholarly journals Differential Hyperacetylation of Histones H3 and H4 upon Promoter-Specific Recruitment of EBNA2 in Epstein-Barr Virus Chromatin

2003 ◽  
Vol 77 (14) ◽  
pp. 8166-8172 ◽  
Author(s):  
Nathalie Alazard ◽  
Henri Gruffat ◽  
Edwige Hiriart ◽  
Alain Sergeant ◽  
Evelyne Manet
Keyword(s):  
B Lymphocytes ◽  
Chromatin Immunoprecipitation ◽  
Epstein Barr Virus ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Viral Promoters ◽  
Epstein Barr ◽  
Cellular Dna ◽  
First Time

ABSTRACT Epstein-Barr virus nuclear antigen 2 (EBNA2) is a transcriptional activator involved in the immortalization of B lymphocytes by the virus. EBNA2 is targeted to the promoters of its responsive genes, via interaction with cellular DNA-binding proteins. Using chromatin immunoprecipitation assays, we show for the first time the conditional recruitment of EBNA2 on two specific viral promoters in vivo and demonstrate a correlation between this recruitment and a local change in the acetylation of histones H3 and H4, which is promoter dependent.

scholarly journals Role for G-Quadruplex RNA Binding by Epstein-Barr Virus Nuclear Antigen 1 in DNA Replication and Metaphase Chromosome Attachment

2009 ◽  
Vol 83 (20) ◽  
pp. 10336-10346 ◽  
Author(s):  
Julie Norseen ◽  
F. Brad Johnson ◽  
Paul M. Lieberman
Keyword(s):  
Dna Replication ◽  
Epstein Barr Virus ◽  
Origin Recognition Complex ◽  
Rna Binding ◽  
Binding Capacity ◽  
Nuclear Antigen ◽  
Metaphase Chromosomes ◽  
Barr Virus ◽  
G Quadruplex ◽  
Epstein Barr

ABSTRACT Latent infection by Epstein-Barr virus (EBV) requires both replication and maintenance of the viral genome. EBV nuclear antigen 1 (EBNA1) is a virus-encoded protein that is critical for the replication and maintenance of the genome during latency in proliferating cells. We have previously demonstrated that EBNA1 recruits the cellular origin recognition complex (ORC) through an RNA-dependent interaction with EBNA1 linking region 1 (LR1) and LR2. We now show that LR1 and LR2 bind to G-rich RNA that is predicted to form G-quadruplex structures. Several chemically distinct G-quadruplex-interacting drugs disrupted the interaction between EBNA1 and ORC. The G-quadruplex-interacting compound BRACO-19 inhibited EBNA1-dependent stimulation of viral DNA replication and preferentially blocked proliferation of EBV-positive cells relative to EBV-negative cell lines. BRACO-19 treatment also disrupted the ability of EBNA1 to tether to metaphase chromosomes, suggesting that maintenance function is also mediated through G-quadruplex recognition. These findings suggest that the EBNA1 replication and maintenance function uses a common G-quadruplex binding capacity of LR1 and LR2, which may be targetable by small-molecule inhibitors.

scholarly journals Epstein–Barr virus nuclear antigen-1 is highly colocalized with interphase chromatin and its newly replicated regions in particular

2002 ◽  
Vol 83 (10) ◽  
pp. 2377-2383 ◽  
Author(s):  
Sayuri Ito ◽  
Eisuke Gotoh ◽  
Shigeru Ozawa ◽  
Kazuo Yanagi
Keyword(s):  
Epstein Barr Virus ◽  
Fluorescent Protein ◽  
Chromosomal Localization ◽  
Nuclear Antigen ◽  
Interphase Chromatin ◽  
Premature Chromosome Condensation ◽  
Metaphase Chromosomes ◽  
Barr Virus ◽  
Epstein Barr ◽  
Green Fluorescent

Epstein–Barr virus (EBV) nuclear antigen-1 (EBNA-1), which binds to both the EBV origin of replication (oriP) and metaphase chromosomes, is essential for the replication/retention and segregation/partition of oriP-containing plasmids. Here the chromosomal localization of EBNA-1 fused to green fluorescent protein (GFP–EBNA-1) is examined by confocal microscopy combined with a ‘premature chromosome condensation’ (PCC) procedure. Analyses show that GFP–EBNA-1 expressed in living cells that lack oriP plasmids is associated with cellular chromatin that has been condensed rapidly by the PCC procedure into identifiable forms that are unique to each phase of interphase as well as metaphase chromosomes. Studies of cellular chromosomal DNAs labelled with BrdU or Cy3-dUTP indicate that GFP–EBNA-1 colocalizes highly with the labelled, newly replicated regions of interphase chromatin in cells. These results suggest that EBNA-1 is associated not only with cellular metaphase chromosomes but also with condensing chromatin/chromosomes and probably with interphase chromatin, especially with its newly replicated regions.

scholarly journals The Amino Terminus of Epstein-Barr Virus (EBV) Nuclear Antigen 1 Contains AT Hooks That Facilitate the Replication and Partitioning of Latent EBV Genomes by Tethering Them to Cellular Chromosomes

2004 ◽  
Vol 78 (21) ◽  
pp. 11487-11505 ◽  
Author(s):  
John Sears ◽  
Maki Ujihara ◽  
Samantha Wong ◽  
Christopher Ott ◽  
Jaap Middeldorp ◽  
...  
Keyword(s):  
Epstein Barr Virus ◽  
Human Cells ◽  
Nuclear Antigen ◽  
Amino Terminus ◽  
Binding Motif ◽  
Metaphase Chromosomes ◽  
Barr Virus ◽  
Binding Domains ◽  
Epstein Barr ◽  
Chromosome Binding

ABSTRACT During latency, Epstein-Barr virus (EBV) is stably maintained as a circular plasmid that is replicated once per cell cycle and partitioned at mitosis. Both these processes require a single viral protein, EBV nuclear antigen 1 (EBNA1), which binds two clusters of cognate binding sites within the latent viral origin, oriP. EBNA1 is known to associate with cellular metaphase chromosomes through chromosome-binding domains within its amino terminus, an association that we have determined to be required not only for the partitioning of oriP plasmids but also for their replication. One of the chromosome-binding domains of EBNA1 associates with a cellular nucleolar protein, EBP2, and it has been proposed that this interaction underlies that ability of EBNA1 to bind metaphase chromosomes. Here we demonstrate that EBNA1's chromosome-binding domains are AT hooks, a DNA-binding motif found in a family of proteins that bind the scaffold-associated regions on metaphase chromosomes. Further, we demonstrate that the ability of EBNA1 to stably replicate and partition oriP plasmids correlates with its AT hook activity and not its association with EBP2. Finally, we examine the contributions of EBP2 toward the ability of EBNA1 to associate with metaphase chromosomes in human cells, as well as support the replication and partitioning of oriP plasmids in human cells. Our results indicate that it is unlikely that EBP2 directly mediates these activities of EBNA1 in human cells.

scholarly journals Characteristics of Epstein-Barr virus activation of human B lymphocytes.

1981 ◽  
Vol 154 (3) ◽  
pp. 832-839 ◽  
Author(s):  
A G Bird ◽  
S Britton ◽  
I Ernberg ◽  
K Nilsson
Keyword(s):  
Epstein Barr Virus ◽  
De Novo ◽  
Human Peripheral Blood ◽  
Protein A ◽  
Plaque Assay ◽  
Nuclear Antigen ◽  
Immunoglobulin Secretion ◽  
Barr Virus ◽  
Epstein Barr

Epstein-Barr virus (EBV) will infect at least every third cell if exposed in vitro to an extensively purified B cell population from human peripheral blood. About 10% of such infected cells will be driven into immunoglobulin synthesis and secretion, as judged by the indirect protein A plaque assay. The appearance of EB nuclear antigen, de novo DNA synthesis, and immunoglobulin secretion are linked phenomena accompanying infection as judged by viral dilution experiments, which yield kinetics of a one-hit order. Induction of immunoglobulin secretion in B cells by EBV requires de novo synthesis of DNA, and consequently, nontransforming EBV (P3HR1) will not induce immunoglobulin secretion and will also specifically block such induction from subsequently added EBV. The termination of immunoglobulin induction by EBV in short-term cultures appears to be T cell dependent.

scholarly journals High Avidity Binding to DNA Protects Ubiquitylated Substrates from Proteasomal Degradation

2011 ◽  
Vol 286 (22) ◽  
pp. 19565-19575 ◽  
Author(s):  
Giuseppe Coppotelli ◽  
Nouman Mughal ◽  
Diego Marescotti ◽  
Maria G. Masucci
Keyword(s):  
Epstein Barr Virus ◽  
Protein Domains ◽  
Proteasomal Degradation ◽  
Nuclear Antigen ◽  
High Avidity ◽  
Dna Protection ◽  
Barr Virus ◽  
Detergent Extraction ◽  
Epstein Barr ◽  
Cellular Dna

Protein domains that act as degradation and stabilization signals regulate the rate of turnover of proteasomal substrates. Here we report that the bipartite Gly-Arg repeat of the Epstein-Barr virus (EBV) nuclear antigen (EBNA)-1 acts as a stabilization signal that inhibits proteasomal degradation in the nucleus by promoting binding to cellular DNA. Protection can be transferred by grafting the domain to unrelated proteasomal substrates and does not involve changes of ubiquitylation. Protection is also afforded by other protein domains that, similar to the Gly-Arg repeat, mediate high avidity binding to DNA, as exemplified by resistance to detergent extraction. Our findings identify high avidity binding to DNA as a portable inhibitory signal that counteracts proteasomal degradation.

scholarly journals Epstein-Barr Virus Nuclear Antigen 3C Putative Repression Domain Mediates Coactivation of the LMP1 Promoter with EBNA-2

2002 ◽  
Vol 76 (1) ◽  
pp. 232-242 ◽  
Author(s):  
Jeffrey Lin ◽  
Eric Johannsen ◽  
Erle Robertson ◽  
Elliott Kieff
Keyword(s):  
Epstein Barr Virus ◽  
Nuclear Antigen ◽  
Raji Cells ◽  
Barr Virus ◽  
Epstein Barr ◽  
Cellular Dna ◽  
High Level ◽  
Necessary And Sufficient ◽  
Two Hybrid ◽  
Repression Domain

ABSTRACT The Epstein-Barr virus (EBV) nuclear antigen 3C (EBNA-3C) regulates virus and cell genes and is essential for EBV-mediated transformation of primary B lymphocytes. EBNA-3C associates with the cellular DNA sequence-specific transcription factors RBP-Jκ and PU.1 and coactivates the EBV LMP1 promoter with EBNA-2 in BL2 and Raji cells under conditions of restrictive growth. We now find that EBNA-3C is similar to EBNA-LP in coactivating the LMP1 promoter with EBNA-2 in non-EBV-infected Burkitt lymphoma cells under conditions of maximal cell growth, whereas the EBV Cp promoter is repressed under the same conditions. EBNA-3A and EBNA-3B coactivation are at most 40% that of EBNA-3C. The RBP-Jκ binding sites of EBNA-2 and the LMP1 promoter are not required for EBNA-3C coactivation, whereas the PU.1 site in the LMP1 promoter is required for EBNA-2-mediated activation and EBNA-3C coactivation. EBNA-3C amino acids (aa) 365 to 545, including most of the previously identified repression domain (M. Bain, R. J. Watson, P. J. Farrell, and M. J. Allday, J. Virol. 70:2481–2489, 1996), are necessary and sufficient for coactivation with wild-type EBNA-2. EBNA-3C can also coactivate with the EBNA-2 acidic activating domain; this activation does not require aa 343 to 545. These data indicate that there are at least two mechanisms by which EBNA-3C coactivates the LMP1 promoter with EBNA-2. Of the proteins that interact with EBNA-3C in a yeast two-hybrid screen, only the ubiquitin-like proteins SUMO-1 and SUMO-3/hSMT3B map to aa 365 to 545, implicating these molecules in EBNA-3C coactivation. In addition, SUMO-1 associates at a high level with EBNA-3C in lymphoblasts. Promoter coactivation by EBNA-3C is likely to be important in ensuring adequate levels of LMP1, while inhibition of the EBNA-Cp promoter under the same conditions prevents uncontrolled up-regulation of EBNA expression from a positive-feedback loop.

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