scholarly journals Epstein–Barr virus nuclear antigen 3A partially coincides with EBNA3C genome-wide and is tethered to DNA through BATF complexes

2014 ◽  
Vol 112 (2) ◽  
pp. 554-559 ◽  
Author(s):  
Stefanie C. S. Schmidt ◽  
Sizun Jiang ◽  
Hufeng Zhou ◽  
Bradford Willox ◽  
Amy M. Holthaus ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Latent Infection ◽  
Protein Complexes ◽  
Nuclear Antigen ◽  
Lymphoblastoid Cell Lines ◽  
Barr Virus ◽  
Genome Wide ◽  
Epstein Barr

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.

scholarly journals Structural, Functional, and Genetic Comparisons of Epstein-Barr Virus Nuclear Antigen 3A, 3B, and 3C Homologues Encoded by the Rhesus Lymphocryptovirus

2000 ◽  
Vol 74 (13) ◽  
pp. 5921-5932 ◽  
Author(s):  
Hua Jiang ◽  
Young-gyu Cho ◽  
Fred Wang
Keyword(s):  
B Cell ◽  
Transcriptional Activation ◽  
Rhesus Monkeys ◽  
Epstein Barr Virus ◽  
Latent Infection ◽  
Nuclear Antigen ◽  
In Vitro Assays ◽  
Barr Virus ◽  
Cell Immortalization ◽  
Epstein Barr

ABSTRACT EBNA-3A, -3B, and -3C are three latent infection nuclear proteins important for Epstein-Barr virus (EBV)-induced B-cell immortalization and the immune response to EBV infection. All three are hypothesized to function as transcriptional transactivators, but little is known about their precise mechanism of action or their role in EBV pathogenesis. We have cloned and studied the three EBNA-3 homologues from a closely related lymphocryptovirus (LCV) which naturally infects rhesus monkeys. The rhesus LCV EBNA-3A, -3B, and -3C homologues have 37, 40, and 36% amino acid identity with the EBV genes, respectively. Function, as measured by in vitro assays, also appears to be conserved with the EBV genes, since the rhesus LCV EBNA-3s can interact with the transcription factor RBP-Jκ and the rhesus LCV EBNA-3C encodes a Q/P-rich domain with transcriptional activation properties. In order to better understand the relationship between these EBV and rhesus LCV latent infection genes, we asked if the rhesus LCV EBNA-3 locus could be recombined into the EBV genome and if it could substitute for the EBV EBNA-3s when assayed for human B-cell immortalization. Recombination between the EBV genome and rhesus LCV DNA was reasonably efficient. However, these studies suggest that the rhesus LCV EBNA-3 locus was not completely interchangeable with the EBV EBNA-3 locus for B-cell immortalization and that at least one determinant of the species restriction for LCV-induced B-cell immortalization maps to the EBNA-3 locus. The overall conservation of EBNA-3 structure and function between EBV and rhesus LCV indicates that rhesus LCV infection of rhesus monkeys can provide an important animal model for studying the role of the EBNA-3 genes in LCV pathogenesis.

scholarly journals Epstein-Barr Virus (EBV) Latent Protein EBNA3A Directly Targets and Silences the STK39 Gene in B Cells Infected by EBV

2018 ◽  
Vol 92 (7) ◽  
Author(s):  
Quentin Bazot ◽  
Kostas Paschos ◽  
Martin J. Allday
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Lines ◽  
Epstein Barr Virus ◽  
Nuclear Antigen ◽  
Lymphoblastoid Cell Lines ◽  
Barr Virus ◽  
Cellular Genes ◽  
Wide Range ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) establishes latent infection in human B cells and is associated with a wide range of cancers. The EBV nuclear antigen 3 (EBNA3) family proteins are critical for B cell transformation and function as transcriptional regulators. It is well established that EBNA3A and EBNA3C cooperate in the regulation of cellular genes. Here, we demonstrate that the gene STK39 is repressed only by EBNA3A. This is the first example of a gene regulated only by EBNA3A in EBV-transformed lymphoblastoid cell lines (LCLs) without the help of EBNA3C. This was demonstrated using a variety of LCLs carrying either knockout, revertant, or conditional EBNA3 recombinants. Investigating the kinetics of EBNA3A-mediated changes in STK39 expression showed that STK39 becomes derepressed quickly after EBNA3A inactivation. This derepression is reversible as EBNA3A reactivation represses STK39 in the same cells expressing a conditional EBNA3A. STK39 is silenced shortly after primary B cell infection by EBV, and no STK39 -encoded protein (SPAK) is detected 3 weeks postinfection. Chromatin immunoprecipitation (ChIP) analysis indicates that EBNA3A directly binds to a regulatory region downstream of the STK39 transcription start site. For the first time, we demonstrated that the polycomb repressive complex 2 with the deposition of the repressive mark H3K27me3 is not only important for the maintenance of an EBNA3A target gene ( STK39 ) but is also essential for the initial establishment of its silencing. Finally, we showed that DNA methyltransferases are involved in the EBNA3A-mediated repression of STK39 . IMPORTANCE EBV is well known for its ability to transform B lymphocytes to continuously proliferating lymphoblastoid cell lines. This is achieved in part by the reprogramming of cellular gene transcription by EBV transcription factors, including the EBNA3 proteins that play a crucial role in this process. In the present study, we found that EBNA3A epigenetically silences STK39 . This is the first gene where EBNA3A has been found to exert its repressive role by itself, without needing its coregulators EBNA3B and EBNA3C. Furthermore, we demonstrated that the polycomb repressor complex is essential for EBNA3A-mediated repression of STK39 . Findings in this study provide new insights into the regulation of cellular genes by the transcription factor EBNA3A.

HAUSP/USP7 as an Epstein–Barr virus target

2004 ◽  
Vol 32 (5) ◽  
pp. 731-732 ◽  
Author(s):  
M.N. Holowaty ◽  
L. Frappier
Keyword(s):  
Epstein Barr Virus ◽  
Latent Infection ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
High Affinity ◽  
Cellular Immortalization ◽  
Epstein Barr ◽  
Epstein Barr Nuclear Antigen

USP7 (also called HAUSP) is a de-ubiquitinating enzyme recently identified as a key regulator of the p53–mdm2 pathway, which stabilizes both p53 and mdm2. We have discovered that the Epstein–Barr nuclear antigen 1 protein of Epstein–Barr virus binds with high affinity to USP7 and disrupts the USP7–p53 interaction. The results have important implications for the role of Epstein–Barr nuclear antigen 1 in the cellular immortalization that is typical of an Epstein–Barr virus latent infection.

scholarly journals Epstein-Barr Virus Nuclear Antigen 1 Does Not Cause Lymphoma in C57BL/6J Mice

2008 ◽  
Vol 82 (8) ◽  
pp. 4180-4183 ◽  
Author(s):  
Myung-Soo Kang ◽  
Vishal Soni ◽  
Roderick Bronson ◽  
Elliott Kieff
Keyword(s):  
Transgenic Mice ◽  
Epstein Barr Virus ◽  
Latent Infection ◽  
Nuclear Antigen ◽  
Barr Virus ◽  
Epstein Barr ◽  
Negative Controls ◽  
Mouse Lymphocytes

ABSTRACT To test whether transgenic Epstein-Barr virus nuclear antigen 1 (EBNA1) expression in C57BL/6 mouse lymphocytes causes lymphoma, EBNA1 expressed in three FVB lineages at two or three times the level of latent infection was crossed up to six successive times into C57BL/6J mice. After five or six crosses, 14/36, (38%) EBNA1 transgenic mice, 11/31 (36%) littermate EBNA1-negative controls, and 9/25 (36%) inbred C57BL/6J mice housed in the same facility had lymphoma. These data indicate that EBNA1 does not significantly increase lymphoma prevalence in C57BL/6J mice.

Genetic loci for Epstein-Barr virus nuclear antigen-1 are associated with risk of multiple sclerosis

2016 ◽  
Vol 22 (13) ◽  
pp. 1655-1664 ◽  
Author(s):  
Yuan Zhou ◽  
Gu Zhu ◽  
Jac C Charlesworth ◽  
Steve Simpson ◽  
Rohina Rubicz ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Genetic Risk ◽  
Epstein Barr Virus ◽  
Meta Analysis ◽  
Nuclear Antigen ◽  
Genetic Loci ◽  
Polygenic Risk ◽  
Barr Virus ◽  
Genome Wide ◽  
Epstein Barr

Background: Infection with the Epstein-Barr virus (EBV) is associated with an increased risk of multiple sclerosis (MS). Objective: We sought genetic loci influencing EBV nuclear antigen-1 (EBNA-1) IgG titers and hypothesized that they may play a role in MS risk. Methods: We performed a genome-wide association study (GWAS) of anti-EBNA-1 IgG titers in 3599 individuals from an unselected twin family cohort, followed by a meta-analysis with data from an independent EBNA-1 GWAS. We then examined the shared polygenic risk between the EBNA-1 GWAS (effective sample size ( Neff) = 5555) and a large MS GWAS ( Neff = 15,231). Results: We identified one locus of strong association within the human leukocyte antigen (HLA) region, of which the most significantly associated genotyped single nucleotide polymorphism (SNP) was rs2516049 ( p = 4.11 × 10−9). A meta-analysis including data from another EBNA-1 GWAS in a cohort of Mexican-American families confirmed that rs2516049 remained the most significantly associated SNP ( p = 3.32 × 10−20). By examining the shared polygenic risk, we show that the genetic risk for elevated anti-EBNA-1 titers is positively correlated with the development of MS, and that elevated EBNA-1 titers are not an epiphenomena secondary to MS. In the joint meta-analysis of EBNA-1 titers and MS, loci at 1p22.1, 3p24.1, 3q13.33, and 10p15.1 reached genome-wide significance ( p < 5 × 10−8). Conclusions: Our results suggest that apart from the confirmed HLA region, the association of anti-EBNA-1 IgG titer with MS risk is also mediated through non-HLA genes, and that studies aimed at identifying genetic loci influencing EBNA immune response provides a novel opportunity to identify new and characterize existing genetic risk factors for MS.

scholarly journals Epstein-Barr Virus Nuclear Antigen Leader Protein Coactivates EP300

2018 ◽  
Vol 92 (9) ◽  
Author(s):  
Chong Wang ◽  
Hufeng Zhou ◽  
Yong Xue ◽  
Jun Liang ◽  
Yohei Narita ◽  
...  
Keyword(s):  
Transcription Factors ◽  
B Cells ◽  
B Cell ◽  
Epstein Barr Virus ◽  
Nuclear Antigen ◽  
Transcription Activator ◽  
Lymphoproliferative Diseases ◽  
Barr Virus ◽  
Leader Protein ◽  
Epstein Barr

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.

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