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 Epstein–Barr virus transcription factor Zta acts through distal regulatory elements to directly control cellular gene expression

2015 ◽  
Vol 43 (7) ◽  
pp. 3563-3577 ◽  
Author(s):  
Sharada Ramasubramanyan ◽  
Kay Osborn ◽  
Rajaei Al-Mohammad ◽  
Ijiel B. Naranjo Perez-Fernandez ◽  
Jianmin Zuo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Epstein Barr Virus ◽  
Regulatory Elements ◽  
Cellular Gene ◽  
Cellular Gene Expression ◽  
Barr Virus ◽  
Virus Transcription ◽  
Epstein Barr ◽  
Distal Regulatory Elements

scholarly journals Functional Interaction of Nuclear Factor Y and Sp1 Is Required for Activation of the Epstein-Barr Virus C Promoter

2003 ◽  
Vol 77 (2) ◽  
pp. 821-829 ◽  
Author(s):  
Cecilia Boreström ◽  
Henrik Zetterberg ◽  
Kristian Liff ◽  
Lars Rymo
Keyword(s):  
Epstein Barr Virus ◽  
Cell Transformation ◽  
Dominant Negative ◽  
Nuclear Antigen ◽  
Nuclear Factor ◽  
Barr Virus ◽  
Nuclear Factor Y ◽  
Epstein Barr ◽  
B Lymphoid ◽  
Virus C

ABSTRACT Two Epstein-Barr virus (EBV) latent cycle promoters, Wp and Cp, are activated sequentially during virus-induced transformation of primary B lymphocytes. Immediately postinfection, viral transcription initiates from Wp, leading to expression of EBV nuclear antigen 2 (EBNA2) and EBNA5. Within 36 h, there is a switch in promoter usage from Wp to the upstream Cp, which leads to expression of EBNA1 to EBNA6. EBNA2 appears to be required for the Wp-to-Cp switch, but the switching mechanism is not fully understood at the molecular level. In a previous investigation we showed that there is an EBNA2-independent activity of reporter constructs containing deletion fragments of Cp in B-lymphoid cell lines, and we demonstrated that Cp activity is highly dependent on several cellular transcription factors, including nuclear factor Y (NF-Y) and Sp1. In the present work, we analyzed the effect of NF-Y on Cp activity in greater detail. We demonstrate that (i) a dominant negative analogue of NF-Y abolishes Cp activity, (ii) NF-Y and Sp1 costimulate Cp, and (iii) the oriPI-EBNA1-induced transactivation of Cp requires concomitant expression of NF-Y and Sp1, although additional factors seem necessary for optimal activation. Furthermore, using the lymphoblastoid cell line EREB2-5, in which EBNA2 function is regulated by estrogen, we demonstrate that inactivation of EBNA2 results in decreased expression of NF-Y and down-regulation of Cp. On reconstitution of the EBNA2 function, the cells enter the cell cycle, NF-Y levels increase, and a concomitant Wp-to-Cp switch occurs. Taken together, our results suggest that NF-Y is essential for Cp activation and that up-regulation of NF-Y may contribute to a successful Wp-to-Cp switch during B-cell transformation.

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 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 Deletion of Epstein-Barr Virus Regulatory Sequences Upstream of the EBNA Gene Promoter Wp1 Is Unfavorable for B-Cell Immortalization

2002 ◽  
Vol 76 (22) ◽  
pp. 11763-11769 ◽  
Author(s):  
Lina I. Yoo ◽  
Josh Woloszynek ◽  
Steven Templeton ◽  
Samuel H. Speck
Keyword(s):  
B Cell ◽  
Transcription Initiation ◽  
Epstein Barr Virus ◽  
Regulatory Region ◽  
Regulatory Sequences ◽  
Recombinant Viruses ◽  
Barr Virus ◽  
Cell Immortalization ◽  
Epstein Barr ◽  
The Impact

ABSTRACT Transcription of the six Epstein-Barr virus (EBV) EBNA genes is coordinately regulated, being driven by either the Cp promoter, which is encoded within the unique region just upstream of the EBV major internal repeat (IR-1), or by the Wp promoter, which is encoded within the IR-1 repeat and thus present in multiple copies. Previous analyses of Cp- and Wp-initiated transcription have identified a shared cis-regulatory element mapping to the region extending from −169 to −369 bp upstream of the Wp transcription initiation site (M. T. Puglielli, N. Desai, and S. H. Speck, J. Virol. 71:120-128, 1997). To assess the impact of this regulatory region on Cp and Wp activity in the context of the viral genome, we attempted to delete this regulatory region upstream of the first copy of Wp (Wp1). While 10 recombinant viruses were obtained in which this deletion was incorporated in the interior of the IR-1 repeat, only a single lymphoblastoid cell line (LCL) immortalized by a recombinant EBV harboring the deletion upstream of Wp1 was recovered. In contrast, using a control targeting vector in which the Wp regulatory sequences were intact but which contained a sequence tag within the W0 exon, we demonstrated that of the five recombinant viruses analyzed in which the crossover event had occurred upstream of the Wp sequence tag, four had incorporated the tagged sequences into Wp1 of the virus. Taken together, these results indicate that deletion of the regulatory sequences from −369 to −169 bp upstream of Wp1 is unfavorable for EBV-driven B-cell immortalization but is tolerated within the interior of the IR-1 repeat. Analysis of promoter usage in the clone 9-60 LCL, in which the W enhancer sequences were deleted upstream of Wp1, revealed the following: (i) the level of Cp-initiated transcription was significantly diminished compared to that of wild-type LCLs; (ii) the decreased Cp-initiated transcription was not efficiently compensated by transcription initiation from Wp1; and (iii) transcription initiation from downstream Wp promoters was detectable. This is the first report of an LCL in which transcription initiation from a Wp downstream of Wp1 has been documented.

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
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