scholarly journals Cellular Transcription Factor Oct-1 Interacts with the Epstein-Barr Virus BRLF1 Protein To Promote Disruption of Viral Latency

2011 ◽  
Vol 85 (17) ◽  
pp. 8940-8953 ◽  
Author(s):  
A. R. Robinson ◽  
S. S. Kwek ◽  
S. R. Hagemeier ◽  
C. K. Wille ◽  
S. C. Kenney
Keyword(s):  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Viral Latency ◽  
Cellular Transcription Factor ◽  
Barr Virus ◽  
Epstein Barr ◽  
Cellular Transcription

scholarly journals Epstein-Barr Virus Immediate-Early Proteins BZLF1 and BRLF1 Activate the ATF2 Transcription Factor by Increasing the Levels of Phosphorylated p38 and c-Jun N-Terminal Kinases

2000 ◽  
Vol 74 (3) ◽  
pp. 1224-1233 ◽  
Author(s):  
Amy L. Adamson ◽  
Dayle Darr ◽  
Elizabeth Holley-Guthrie ◽  
Robert A. Johnson ◽  
Amy Mauser ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Viral Latency ◽  
Immediate Early ◽  
Expression Vectors ◽  
Protein Z ◽  
Barr Virus ◽  
Ebv Infection ◽  
Early Protein ◽  
Epstein Barr

ABSTRACT Expression of either Epstein-Barr virus (EBV) immediate-early protein BZLF1 (Z) or BRLF1 (R) is sufficient to convert EBV infection from the latent to lytic form. Disruption of viral latency requires transcriptional activation of the Z and R promoters. The Z and R proteins are transcriptional activators, and each immediate-early protein activates expression of the other immediate-early protein. Z activates the R promoter through a direct binding mechanism. However, R does not bind directly to the Z promoter. In this study, we demonstrate that the ZII element (a cyclic AMP response element site) in the Z promoter is required for efficient activation by R. The ZII element has been shown to be important for induction of lytic EBV infection by tetradecanoyl phorbol acetate and surface immunoglobulin cross-linking and is activated by Z through an indirect mechanism. We demonstrate that both R and Z activate the cellular stress mitogen-activated protein (MAP) kinases, p38 and JNK, resulting in phosphorylation (and activation) of the cellular transcription factor ATF2. Furthermore, we show that the ability of R to induce lytic EBV infection in latently infected cells is significantly reduced by inhibition of either the p38 kinase or JNK pathways. In contrast, inhibition of stress MAP kinase pathways does not impair the ability of Z expression vectors to disrupt viral latency, presumably because expression of Z under the control of a strong heterologous promoter bypasses the need to activate Z transcription. Thus, both R and Z can activate the Z promoter indirectly by inducing ATF2 phosphorylation, and this activity appears to be important for R-induced disruption of viral latency.

scholarly journals HCF1 and OCT2 Cooperate with EBNA1 To Enhance OriP-Dependent Transcription and Episome Maintenance of Latent Epstein-Barr Virus

2016 ◽  
Vol 90 (11) ◽  
pp. 5353-5367 ◽  
Author(s):  
Jayaraju Dheekollu ◽  
Andreas Wiedmer ◽  
Daniel Sentana-Lledo ◽  
Joel Cassel ◽  
Troy Messick ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Epstein Barr Virus ◽  
Histone H3 ◽  
Type I ◽  
Barr Virus ◽  
Cellular Factors ◽  
Epstein Barr ◽  
Simplex Virus

ABSTRACTEpstein-Barr virus (EBV) establishes latent infections as multicopy episomes with complex patterns of viral gene transcription and chromatin structure. The EBV origin of plasmid replication (OriP) has been implicated as a critical control element for viral transcription, as well as viral DNA replication and episome maintenance. Here, we examine cellular factors that bind OriP and regulate histone modification, transcription regulation, and episome maintenance. We found that OriP is enriched for histone H3 lysine 4 (H3K4) methylation in multiple cell types and latency types. Host cell factor 1 (HCF1), a component of the mixed-lineage leukemia (MLL) histone methyltransferase complex, and transcription factor OCT2 (octamer-binding transcription factor 2) bound cooperatively with EBNA1 (Epstein-Barr virus nuclear antigen 1) at OriP. Depletion of OCT2 or HCF1 deregulated latency transcription and histone modifications at OriP, as well as the OriP-regulated latency type-dependent C promoter (Cp) and Q promoter (Qp). HCF1 depletion led to a loss of histone H3K4me3 (trimethylation of histone H3 at lysine 4) and H3 acetylation at Cp in type III latency and Qp in type I latency, as well as an increase in heterochromatic H3K9me3 at these sites. HCF1 depletion resulted in the loss of EBV episomes from Burkitt's lymphoma cells with type I latency and reactivation from lymphoblastoid cells (LCLs) with type III latency. These findings indicate that HCF1 and OCT2 function at OriP to regulate viral transcription, histone modifications, and episome maintenance. As HCF1 is best known for its function in herpes simplex virus 1 (HSV-1) immediate early gene transcription, our findings suggest that EBV latency transcription shares unexpected features with HSV gene regulation.IMPORTANCEEBV latency is associated with several human cancers. Viral latent cycle gene expression is regulated by the epigenetic control of the OriP enhancer region. Here, we show that cellular factors OCT2 and HCF1 bind OriP in association with EBNA1 to maintain elevated histone H3K4me3 and transcriptional enhancer function. HCF1 is known as a transcriptional coactivator of herpes simplex virus (HSV) immediate early (IE) transcription, suggesting that OriP enhancer shares aspects of HSV IE transcription control.

scholarly journals Promoter-Proximal Regulatory Elements Involved in oriP-EBNA1-Independent and -Dependent Activation of the Epstein-Barr Virus C Promoter in B-Lymphoid Cell Lines

2001 ◽  
Vol 75 (13) ◽  
pp. 5796-5811 ◽  
Author(s):  
Tina Nilsson ◽  
Henrik Zetterberg ◽  
Yuyan Camilla Wang ◽  
Lars Rymo
Keyword(s):  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Regulatory Elements ◽  
Negative Regulator ◽  
Regulatory Sequences ◽  
Barr Virus ◽  
Group I ◽  
Epstein Barr ◽  
B Lymphoid ◽  
Virus C

ABSTRACT The identification of the cellular factors that control the transcription regulatory activity of the Epstein-Barr virus C promoter (Cp) is fundamental to the understanding of the molecular mechanisms that control virus latent gene expression. Using transient transfection of reporter plasmids in group I phenotype B-lymphoid cells, we have previously shown that the −248 to −55 region (−248/−55 region) of Cp contains elements that are essential fororiPI-EBNA1-dependent as well asoriPI-EBNA1-independent activation of the promoter. We now establish the importance of this region by a detailed mutational analysis of reporter plasmids carrying Cp regulatory sequences together with or without oriPI. The reporter plasmids were transfected into group I phenotype Rael cells and group III phenotype cbc-Rael cells, and the Cp activity measured was correlated with the binding of candidate transcription factors in electrophoretic mobility shift assays and further assessed in cotransfection experiments. We show that the NF-Y transcription factor interacts with the previously identified CCAAT box in the −71/−63 Cp region (M. T. Puglielli, M. Woisetschlaeger, and S. H. Speck, J. Virol. 70:5758–5768, 1996). We also show that members of the C/EBP transcription factor family interact with a C/EBP consensus sequence in the −119/−112 region of Cp and that this interaction is important for promoter activity. A central finding is the identification of a GC-rich sequence in the −99/−91 Cp region that is essential fororiPI-EBNA1-independent as well asoriPI-EBNA1-dependent activity of the promoter. This region contains overlapping binding sites for Sp1 and Egr-1, and our results suggest that Sp1 is a positive and Egr-1 is a negative regulator of Cp activity. Furthermore, we demonstrate that a reporter plasmid that in addition to oriPI contains only the −111/+76 region of Cp still retains the ability to be activated by EBNA1.

scholarly journals The BRRF1 Early Gene of Epstein-Barr Virus Encodes a Transcription Factor That Enhances Induction of Lytic Infection by BRLF1

2004 ◽  
Vol 78 (10) ◽  
pp. 4983-4992 ◽  
Author(s):  
Gregory K. Hong ◽  
Henri-Jacques Delecluse ◽  
Henri Gruffat ◽  
Thomas E. Morrison ◽  
Wen-Hai Feng ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Cell Types ◽  
Early Gene ◽  
Barr Virus ◽  
Ebv Infection ◽  
Early Protein ◽  
293 Cells ◽  
Latently Infected ◽  
Epstein Barr

ABSTRACT The switch from the latent to the lytic form of Epstein-Barr virus (EBV) infection is mediated by expression of the viral immediate-early (IE) proteins, BZLF1 (Z) and BRLF1 (R). An EBV early protein, BRRF1 (Na), is encoded by the opposite strand of the BRLF1 intron, but the function of this nuclear protein in the viral life cycle is unknown. Here we demonstrate that Na enhances the R-mediated induction of lytic EBV infection in 293 cells latently infected with a recombinant EBV (R-KO) defective for the expression of both R and Na. Na also enhances R-induced lytic infections in a gastric carcinoma line (AGS) carrying the R-KO virus, although it has no effect in a Burkitt lymphoma line (BL-30) stably infected with the same mutant virus. We show that Na is a transcription factor that increases the ability of R to activate Z expression from the R-KO viral genome in 293 cells and that Na by itself activates the Z promoter (Zp) in EBV-negative cells. Na activation of Zp requires a CRE motif (ZII), and a consensus CRE motif is sufficient to transfer Na responsiveness to the heterologous E1b promoter. Furthermore, we show that Na enhances the transactivator function of a Gal4-c-Jun fusion protein but does not increase the transactivator function of other transcription factors (including ATF-1, ATF-2, and CREB) known to bind CRE motifs. Na expression in cells results in increased levels of a hyperphosphorylated form of c-Jun, suggesting a mechanism by which Na activates c-Jun. Our results indicate that Na is a transcription factor that activates the EBV Zp IE promoter through its effects on c-Jun and suggest that Na cooperates with BRLF1 to induce the lytic form of EBV infection in certain cell types.

scholarly journals The interaction of Epstein-Barr virus encoded transcription factor EBNA2 with multiple sclerosis risk loci is dependent on the risk genotype

EBioMedicine ◽  
2021 ◽  
Vol 71 ◽  
pp. 103572 ◽  
Author(s):  
Jeremy Thomas Keane ◽  
Ali Afrasiabi ◽  
Stephen Donald Schibeci ◽  
Sanjay Swaminathan ◽  
Grant Peter Parnell ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Risk Genotype ◽  
Barr Virus ◽  
Multiple Sclerosis Risk ◽  
Epstein Barr

scholarly journals Induction of the Early Growth Response 1 Gene by Epstein-Barr Virus Lytic Transactivator Zta

2006 ◽  
Vol 80 (15) ◽  
pp. 7748-7755 ◽  
Author(s):  
Yao Chang ◽  
Heng-Huan Lee ◽  
Yu-Te Chen ◽  
Jean Lu ◽  
Shih-Yi Wu ◽  
...  
Keyword(s):  
Epstein Barr Virus ◽  
Growth Response ◽  
Early Growth ◽  
Early Growth Response ◽  
Cellular Transcription Factor ◽  
Barr Virus ◽  
Ebv Reactivation ◽  
Epstein Barr ◽  
Spontaneous Expression ◽  
Early Growth Response 1

ABSTRACT Early growth response 1 (Egr-1) is a cellular transcription factor involved in diverse biologic functions. Egr-1 has been associated with Epstein-Barr virus (EBV) infection, but it is still unknown whether any EBV protein regulates Egr-1 expression. In this study, we first showed that EBV reactivation is involved in upregulation of Egr-1 and that Egr-1 can be induced by Zta, an EBV lytic transactivator. Zta not only binds to the Egr-1 promoter but also activates the ERK signaling pathway to trigger binding of Elk-1 to the Egr-1 promoter. In addition, knockdown of Egr-1 significantly reduces the spontaneous expression of Zta and Rta in EBV-infected 293 cells, suggesting that a positive-feedback network involving Egr-1 is required for EBV reactivation. This study also implies that Zta has the potential to affect expression of certain genes through Egr-1.

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