scholarly journals E2F1, ARID3A/Bright and Oct-2 factors bind to the Epstein–Barr virus C promoter, EBNA1 and oriP, participating in long-distance promoter–enhancer interactions

2012 ◽  
Vol 93 (5) ◽  
pp. 1065-1075 ◽  
Author(s):  
Cecilia Boreström ◽  
Alma Forsman ◽  
Ulla Rüetschi ◽  
Lars Rymo

The Epstein–Barr virus (EBV) C promoter (Cp) regulates several genes required for B-cell proliferation in latent EBV infection. The family of repeats (FR) region of the latent origin of plasmid replication (oriP) functions as an Epstein–Barr nuclear antigen 1 (EBNA1)-dependent distant enhancer of Cp activity, and the enhancer–promoter interaction is mediated by a higher-order multi-protein complex containing several copies of EBNA1. Using DNA-affinity purification with a 170 bp region of the Cp in combination with mass spectrometry, we identified the cell cycle-regulatory protein E2F1, the E2F-binding protein ARID3A, and the B-cell-specific transcription factor Oct-2 as components of this multi-protein complex. Binding of the three factors to the FR region of oriP was determined by DNA-affinity and immunoblot analysis. Co-immunoprecipitation and proximity ligation analysis revealed that the three factors, E2F1, ARID3A and Oct-2, interact with each other as well as with EBNA1 in the nuclei of EBV-positive cells. Using the chromatin immunoprecipitation assay, we showed that E2F1 and Oct-2 interacted with the FR part of oriP and the Cp, but the ARID3A interaction was, however, only detected at the Cp. Our findings support the hypothesis that EBNA1 initiates transcription at the Cp via interactions between multiple EBNA1 homodimers and cellular transcription factors in a large molecular machinery that forms a dynamic interaction between Cp and FR.

2018 ◽  
Vol 92 (9) ◽  
Author(s):  
Chong Wang ◽  
Hufeng Zhou ◽  
Yong Xue ◽  
Jun Liang ◽  
Yohei Narita ◽  
...  

ABSTRACTEpstein-Barr virus nuclear antigen (EBNA) leader protein (EBNALP) is one of the first viral genes expressed upon B-cell infection. EBNALP is essential for EBV-mediated B-cell immortalization. EBNALP is thought to function primarily by coactivating EBNA2-mediated transcription. Chromatin immune precipitation followed by deep sequencing (ChIP-seq) studies highlight that EBNALP frequently cooccupies DNA sites with host cell transcription factors (TFs), in particular, EP300, implicating a broader role in transcription regulation. In this study, we investigated the mechanisms of EBNALP transcription coactivation through EP300. EBNALP greatly enhanced EP300 transcription activation when EP300 was tethered to a promoter. EBNALP coimmunoprecipitated endogenous EP300 from lymphoblastoid cell lines (LCLs). EBNALP W repeat serine residues 34, 36, and 63 were required for EP300 association and coactivation. Deletion of the EP300 histone acetyltransferase (HAT) domain greatly reduced EBNALP coactivation and abolished the EBNALP association. An EP300 bromodomain inhibitor also abolished EBNALP coactivation and blocked the EP300 association with EBNALP. EBNALP sites cooccupied by EP300 had significantly higher ChIP-seq signals for sequence-specific TFs, including SPI1, RelA, EBF1, IRF4, BATF, and PAX5. EBNALP- and EP300-cooccurring sites also had much higher H3K4me1 and H3K27ac signals, indicative of activated enhancers. EBNALP-only sites had much higher signals for DNA looping factors, including CTCF and RAD21. EBNALP coactivated reporters under the control of NF-κB or SPI1. EP300 inhibition abolished EBNALP coactivation of these reporters. Clustered regularly interspaced short palindromic repeat interference targeting of EBNALP enhancer sites significantly reduced target gene expression, including that of EP300 itself. These data suggest a previously unrecognized mechanism by which EBNALP coactivates transcription through subverting of EP300 and thus affects the expression of LCL genes regulated by a broad range of host TFs.IMPORTANCEEpstein-Barr virus was the first human DNA tumor virus discovered over 50 years ago. EBV is causally linked to ∼200,000 human malignancies annually. These cancers include endemic Burkitt lymphoma, Hodgkin lymphoma, lymphoma/lymphoproliferative disease in transplant recipients or HIV-infected people, nasopharyngeal carcinoma, and ∼10% of gastric carcinoma cases. EBV-immortalized human B cells faithfully model key aspects of EBV lymphoproliferative diseases and are useful models of EBV oncogenesis. EBNALP is essential for EBV to transform B cells and transcriptionally coactivates EBNA2 by removing repressors from EBNA2-bound DNA sites. Here, we found that EBNALP can also modulate the activity of the key transcription activator EP300, an acetyltransferase that activates a broad range of transcription factors. Our data suggest that EBNALP regulates a much broader range of host genes than was previously appreciated. A small-molecule inhibitor of EP300 abolished EBNALP coactivation of multiple target genes. These findings suggest novel therapeutic approaches to control EBV-associated lymphoproliferative diseases.


Oncogene ◽  
2019 ◽  
Vol 39 (9) ◽  
pp. 2028-2028
Author(s):  
Jiayu Wang ◽  
Noemi Nagy ◽  
Maria G. Masucci

This article was originally published under Springer Nature’s License to Publish, but has now been made available under a CC BY 4.0 license. The PDF and HTML versions of the paper have been modified accordingly.


1985 ◽  
Vol 162 (1) ◽  
pp. 45-59 ◽  
Author(s):  
D A Thorley-Lawson ◽  
K P Mann

We have used Epstein-Barr virus (EBV) infection in vitro to delineate two distinct stages in B cell activation. Previous studies have shown that the BLAST-2 (EBVCS) (EBV cell surface) activation antigen is expressed on a small fraction of B cells within 24 h of stimulation with a variety of agents, including mitogens and EBV. In this study, we have been able to isolate the BLAST-2 (EBVCS)+ cells early after activation/infection with EBV. These cells are small B cells that are actively synthesizing RNA but not DNA, and are, therefore, clearly distinct from large proliferating lymphoblasts. In addition, they contain multiple copies of the EBV genome, express the viral nuclear antigen (EBNA) and, most importantly, proceed to undergo transformation when placed back in culture. By comparison, the BLAST-2 (EBVCS)- population does not undergo transformation, even though a fraction of these cells are activated for RNA synthesis and express EBNA. Thus, using the EBV system, we have been able to show directly that an activated B cell first expresses the BLAST-2 (EBVCS) antigen concomitant with an increase in RNA synthesis, and then subsequently proceeds to differentiate into a proliferating lymphoblast.


2014 ◽  
Vol 112 (2) ◽  
pp. 554-559 ◽  
Author(s):  
Stefanie C. S. Schmidt ◽  
Sizun Jiang ◽  
Hufeng Zhou ◽  
Bradford Willox ◽  
Amy M. Holthaus ◽  
...  

Epstein–Barr Virus (EBV) conversion of B-lymphocytes to Lymphoblastoid Cell Lines (LCLs) requires four EBV nuclear antigen (EBNA) oncoproteins: EBNA2, EBNALP, EBNA3A, and EBNA3C. EBNA2 and EBNALP associate with EBV and cell enhancers, up-regulate the EBNA promoter, MYC, and EBV Latent infection Membrane Proteins (LMPs), which up-regulate BCL2 to protect EBV-infected B-cells from MYC proliferation-induced cell death. LCL proliferation induces p16INK4A and p14ARF-mediated cell senescence. EBNA3A and EBNA3C jointly suppress p16INK4A and p14ARF, enabling continuous cell proliferation. Analyses of the EBNA3A human genome-wide ChIP-seq landscape revealed 37% of 10,000 EBNA3A sites to be at strong enhancers; 28% to be at weak enhancers; 4.4% to be at active promoters; and 6.9% to be at weak and poised promoters. EBNA3A colocalized with BATF-IRF4, ETS-IRF4, RUNX3, and other B-cell Transcription Factors (TFs). EBNA3A sites clustered into seven unique groups, with differing B-cell TFs and epigenetic marks. EBNA3A coincidence with BATF-IRF4 or RUNX3 was associated with stronger EBNA3A ChIP-Seq signals. EBNA3A was at MYC, CDKN2A/B, CCND2, CXCL9/10, and BCL2, together with RUNX3, BATF, IRF4, and SPI1. ChIP-re-ChIP revealed complexes of EBNA3A on DNA with BATF. These data strongly support a model in which EBNA3A is tethered to DNA through a BATF-containing protein complexes to enable continuous cell proliferation.


2011 ◽  
Vol 13 (9) ◽  
pp. 487-496 ◽  
Author(s):  
Ryan P. Flynn ◽  
Jeana Zacharias ◽  
Xianzheng Zhou ◽  
Mark L. Cannon ◽  
Nicola J. Philpott

Blood ◽  
1987 ◽  
Vol 70 (5) ◽  
pp. 1619-1623 ◽  
Author(s):  
S Doi ◽  
H Ohno ◽  
E Tatsumi ◽  
Y Arita ◽  
H Kamesaki ◽  
...  

Abstract A novel cell line, FL-18, was established from the pleural effusion of a patient with follicular small cleaved cell lymphoma. At the same time, an Epstein-Barr virus (EBV) nuclear antigen (EBNA)-positive cell line, FL-18-EB, was established from the EBV-infected culture of the same pleural effusion cells. Both cell lines had the same monoclonal surface immunoglobulin (IgG kappa), and they had the same karyotype as that of the fresh pleural effusion cells in which a reciprocal translocation between the long arm of chromosomes 14 and 18 [t(14;18)(q32;q21)] was detected. Gene rearrangement analysis of immunoglobulin heavy-chain gene (JH) and kappa light-chain gene (J kappa) showed the same rearranged configuration in the two cell lines; however, some morphological and phenotypic differences were found. The FL-18-EB cells, which were morphologically similar to common EBNA- positive lymphoblastoid cell lines of normal B cell origin at the initial phase of culture, were larger than the FL-18 cells and contained multinucleated giant cells. The FL-18 cells lacked cytoplasmic immunoglobulin and were positive for common acute lymphoblastic leukemia antigen (CALLA), whereas the FL-18-EB cells had cytoplasmic immunoglobulin and were negative for CALLA. Thus, the phenotype of FL-18-EB seems to be a result of a shift by EBV infection to a more mature stage in the B cell differentiation pathway than that of FL-18. The paired availability of EBV-free and EBV-infected cell lines of a neoplastic clone is unique and valuable in considering EBV infectibility of neoplastic B cells and resultant phenotypic changes.


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