Protein Kinase Activity Associated with a Cell Cycle Regulated, Membrane-Bound Epstein-Barr Virus Induced Early Antigen

Intervirology ◽  
1990 ◽  
Vol 31 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Malda M. Kocache ◽  
Gary R. Pearson
Keyword(s):  
Cell Cycle ◽  
Protein Kinase ◽  
Epstein Barr Virus ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Early Antigen ◽  
Barr Virus ◽  
A Cell ◽  
Membrane Bound ◽  
Epstein Barr

scholarly journals A Protein Kinase Activity Associated with Epstein-Barr Virus BGLF4 Phosphorylates the Viral Early Antigen EA-D In Vitro

2000 ◽  
Vol 74 (7) ◽  
pp. 3093-3104 ◽  
Author(s):  
Mei-Ru Chen ◽  
Shin-Jye Chang ◽  
Hsiaowen Huang ◽  
Jen-Yang Chen
Keyword(s):  
Protein Kinase ◽  
Epstein Barr Virus ◽  
Kinase Activity ◽  
Kinase Assay ◽  
Specific Antiserum ◽  
Protein Kinase Activity ◽  
Early Antigen ◽  
Barr Virus ◽  
Epstein Barr

ABSTRACT The Epstein-Barr virus (EBV) open reading frame BGLF4 was identified as a potential Ser/Thr protein kinase gene through the recognition of amino acid sequence motifs characteristic of conserved regions within the catalytic domains of protein kinases. In order to investigate this potential kinase activity, BGLF4 was expressed inEscherichia coli and the purified protein was used to generate a specific antiserum. Recombinant vaccinia virus vTF7-3, which expresses the T7 RNA polymerase, was used to infect 293 and 293T cells after transient transfection with a plasmid containing BGLF4 under the control of the T7 promoter. Autophosphorylation of the BGLF4 protein was demonstrated using the specific antiserum in an immune complex kinase assay. In addition, EBNA-1-tagged BGLF4 and EBNA-1 monoclonal antibody 5C11 were used to demonstrate the specificity of the kinase activity and to locate BGLF4 in the cytoplasm of transfected cells. Manganese ions were found to be essential for autophosphorylation of BGLF4, and magnesium can stimulate the activity. BGLF4 can utilize GTP, in addition to ATP, as a phosphate donor in this assay. BGLF4 can phosphorylate histone and casein in vitro. Among the potential viral protein substrates we examined, the EBV early antigen (EA-D, BMRF1), a DNA polymerase accessory factor and an important transactivator during lytic infection, was found to be phosphorylated by BGLF4 in vitro. Amino acids 1 to 26 of BGLF4, but not the predicted conserved catalytic domain, were found to be essential for autophosphorylation of BGLF4.

Protein kinase activity associated with Epstein-Barr virus-determined nuclear antigen

Virology ◽  
1981 ◽  
Vol 113 (2) ◽  
pp. 512-520 ◽  
Author(s):  
Tohru Kamata ◽  
Kazutaka Takaki ◽  
Yorio Hinuma ◽  
Yasushi Watanabe
Keyword(s):  
Protein Kinase ◽  
Epstein Barr Virus ◽  
Kinase Activity ◽  
Nuclear Antigen ◽  
Protein Kinase Activity ◽  
Barr Virus ◽  
Epstein Barr

scholarly journals Cell Cycle Association of the Retinoblastoma Protein Rb and the Histone Demethylase LSD1 with the Epstein-Barr Virus Latency Promoter Cp

2008 ◽  
Vol 82 (7) ◽  
pp. 3428-3437 ◽  
Author(s):  
Charles M. Chau ◽  
Zhong Deng ◽  
Hyojueng Kang ◽  
Paul M. Lieberman
Keyword(s):  
Cell Cycle ◽  
Epstein Barr Virus ◽  
Affinity Purification ◽  
Histone H3 ◽  
Histone Demethylase ◽  
Stable Complex ◽  
Dependent Manner ◽  
Barr Virus ◽  
A Cell ◽  
Epstein Barr

ABSTRACT The Epstein-Barr virus C promoter (Cp) regulates the major multicistronic transcript encoding the EBNA-LP, 1, 2, and 3 genes required for B-cell proliferation during latency. The growth-transforming potential of these viral genes suggests that they must be tightly regulated with the host cell cycle and differentiation process. To better understand Cp regulation, we used DNA affinity purification to identify cellular and viral proteins that bind to Cp in latently infected cells. Several previously unknown factors were identified, including the cell cycle regulatory proteins E2F1 and Rb. E2F1 bound to a specific site in Cp located in the core Cp region 3′ of the known EBNA2-responsive RBP-Jk (CSL, CBF1) binding site. The histone H3 K4 demethylase LSD1 (BCC110) was also identified by DNA affinity and was shown to form a stable complex with Rb. Coimmunoprecipitation assays demonstrated that E2F1, Rb, and LSD1 bind to Cp in a cell cycle-dependent manner. Rb and LSD1 binding to Cp increased after the S phase, corresponding to a decrease in histone H3 K4 methylation and Cp transcription. Coimmunoprecipitation and immunofluorescence assays reveal that LSD1 interacts with Rb. Surprisingly, LSD1 did not coimmunoprecipitate with E2F1, suggesting that it associates with Rb independently of E2F1. Depletion of LSD1 by small interfering RNAs inhibited Cp basal transcription levels, and overexpression of LSD1 altered the cell cycle profile in p53-positive (p53+), but not p53-negative (p53−), HCT cells. These findings indicate that Cp is a cell cycle-regulated promoter that is under the control of Rb and the histone demethylase LSD1 in multiple latency types.

scholarly journals Epstein–Barr virus-encoded protein kinase BGLF4 mediates hyperphosphorylation of cellular elongation factor 1δ (EF-1δ): EF-1δ is universally modified by conserved protein kinases of herpesviruses in mammalian cells

2001 ◽  
Vol 82 (6) ◽  
pp. 1457-1463 ◽  
Author(s):  
Kentaro Kato ◽  
Yasushi Kawaguchi ◽  
Michiko Tanaka ◽  
Mie Igarashi ◽  
Akihiko Yokoyama ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinases ◽  
Mammalian Cells ◽  
Epstein Barr Virus ◽  
Elongation Factor ◽  
Protein Kinase Activity ◽  
Translation Elongation ◽  
Barr Virus ◽  
Epstein Barr ◽  
Simplex Virus

Translation elongation factor 1δ (EF-1δ) is hyperphosphorylated in various mammalian cells infected with alpha-, beta- and gammaherpesviruses and EF-1δ modification is mediated by viral protein kinases, including UL13 of herpes simplex virus type 1 and UL97 of human cytomegalovirus. In this study, the following is reported. (i) BGLF4 encoded by the prototype gammaherpesvirus Epstein–Barr virus was purified as a fusion protein that was labelled with [γ-32P]ATP and labelling was eliminated by phosphatase. (ii) The ratio of the hyperphosphorylated form of human EF-1δ was increased both in Sf9 cells after infection with baculoviruses expressing GST–BGLF4 fusion proteins and in COS-7 cells after transfection with a BGLF4 expression plasmid. These results indicate that purified BGLF4 possesses protein kinase activity and mediates EF-1δ hyperphosphorylation. These data also support the hypothesis that the protein kinases that are conserved by herpesviruses universally mediate EF-1δ modification in mammalian cells.

scholarly journals Epstein-Barr Virus miR-BART1-3p Regulates the miR-17-92 Cluster by Targeting E2F3

2021 ◽  
Vol 22 (20) ◽  
pp. 10936
Author(s):  
Myung Chan Park ◽  
Hyoji Kim ◽  
Hoyun Choi ◽  
Mee Soo Chang ◽  
Suk Kyeong Lee
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Gastric Carcinoma ◽  
Epstein Barr Virus ◽  
Carcinoma Cells ◽  
G1 Arrest ◽  
Protein Levels ◽  
Barr Virus ◽  
A Cell ◽  
Epstein Barr

Epstein-Barr virus (EBV) is associated with several tumors and generates BamHI A rightward transcript (BART) microRNAs (miRNAs) from BART transcript introns. These BART miRNAs are expressed at higher levels in EBV-associated epithelial malignancies than in EBV-infected B lymphomas. To test the effects of EBV miRNA on the cell cycle and cell growth, we transfected miR-BART1-3p, a highly expressed EBV-associated miRNA, into gastric carcinoma cells. We found that miR-BART1-3p induced G0/G1 arrest and suppressed cell growth in gastric carcinoma cells. As our microarray analyses showed that E2F3, a cell cycle regulator, was inhibited by EBV infection, we hypothesized that miR-BART1-3p regulates E2F3. Luciferase assays revealed that miR-BART1-3p directly targeted the 3′-UTR of E2F3 mRNA. Both E2F3 mRNA and encoded protein levels were reduced following miR-BART1-3p transfection. In contrast, E2F3 expression in AGS-EBV cells transfected with a miR-BART1-3p inhibitor was enhanced. As E2F3 has been shown to regulate the expression of highly conserved miR-17-92 clusters in vertebrates, we examined whether this expression is affected by miR-BART1-3p, which can downregulate E2F3. The expression of E2F3, miR-17-92a-1 cluster host gene (MIR17HG), and miR-17-92 cluster miRNAs was significantly reduced in EBV-associated gastric carcinoma (EBVaGC) patients compared with EBV-negative gastric carcinoma (EBVnGC) patients. Further, miR-BART1-3p as well as the siRNA specific to E2F3 inhibited the expression of the miR-17-92 cluster, while inhibition of miR-BART1-3p enhanced the expression of the miR-17-92 cluster in cultured GC cells. Our results suggest a possible role of miR-BART1-3p in cell cycle regulation and in regulation of the miR-17-92 cluster through E2F3 suppression.

scholarly journals Recurrent Erythema Annulare Centrifugum due to Influenza Type A

2021 ◽  
pp. 134-140
Author(s):  
Luca Ena ◽  
Vittorio Mazzarello ◽  
Marco Ferrari ◽  
Pasquale Ena
Keyword(s):  
Epstein Barr Virus ◽  
Local Treatment ◽  
Type A ◽  
Barr Virus ◽  
Ebv Infection ◽  
Influenza Type ◽  
Erythema Annulare Centrifugum ◽  
A Cell ◽  
Epstein Barr ◽  
Calcipotriol Betamethasone

Erythema annulare centrifugum (EAC) is a rare erythema characterized by erythematous and urticarial papules or annular plaques that enlarges centrifugally. The lesions usually involve the thighs and the legs. Several disorders are occasionally associated with EAC, infections, including mycoses, bacteria, or viruses and drugs have also been regarded as possible causes of this eruption. We present a 42-year-old dark-skinned woman affected by recurrent EAC that appeared secondary to influenza type A (H1N1). Histopathology showed a superficial form of EAC. In our case, a previous cytomegalovirus and Epstein-Barr virus (EBV) infection were identified and no underlying other diseases were found. Clarithromycin with calcipotriol betamethasone treatment was temporarily efficacious. In the last 3 years, the lesions started to appear every 2 weeks and tended to regress with local treatment after a variable period. We believe that the latent cytomegalovirus and the reactivity induced by EBV combined with influenza can determine, in our case, a cell mediate cutaneous immune response, which leads to the peculiar inflammatory disease known as EAC.

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