scholarly journals Identification of Epstein-Barr Virus RK-BARF0-Interacting Proteins and Characterization of Expression Pattern

2004 ◽  
Vol 78 (23) ◽  
pp. 12848-12856 ◽  
Author(s):  
Natalie J. Thornburg ◽  
Shuichi Kusano ◽  
Nancy Raab-Traub
Keyword(s):  
Cell Lines ◽  
Epstein Barr Virus ◽  
Interacting Proteins ◽  
Cellular Functions ◽  
Barr Virus ◽  
Acid Protein ◽  
Infected Cells ◽  
Epstein Barr ◽  
Endoplasmic Reticulum Targeting

ABSTRACT The Epstein-Barr virus (EBV) BamHI A transcripts are a family of transcripts that are differentially spliced and can be detected in multiple EBV-associated malignancies. Several of the transcripts may encode proteins. One transcript of interest, RK-BARF0, is proposed to encode a 279-amino-acid protein with a possible endoplasmic reticulum-targeting sequence. In this study, the properties of RK-BARF0 were examined through identification of cellular-interacting proteins through yeast two-hybrid analysis and characterization of its expression in EBV-infected cells and tumors. In addition to the interaction previously identified with cellular Notch, it was determined that RK-BARF0 also bound cellular human I-mfa domain-containing protein (HIC), epithelin, and scramblase. An interaction between RK-BARF0 and Notch or epithelin induced proteasome-dependent degradation of Notch and epithelin but not of HIC or scramblase. Low levels of endogenous Notch expression in EBV-positive cell lines may correlate with RK-BARF0 expression. However, a screen of EBV-positive cell lines and tumors with an affinity-purified α-RK-BARF0 antiserum did not consistently detect RK-BARF0. These data suggest that while RK-BARF0 may have important cellular functions during EBV infection, and while the phenotype of EBV-positive cells suggest its expression, RK-BARF0 levels may be too low to detect.

Subcellular localization of the latent membrane protein LMP-1 in Epstein-Barr virus infected cells by immunogold EM

1994 ◽  
Vol 52 ◽  
pp. 248-249
Author(s):  
D. N. Misra ◽  
R. M. Agostini ◽  
E. J. Yunis
Keyword(s):  
Membrane Protein ◽  
Subcellular Localization ◽  
Cell Lines ◽  
Epstein Barr Virus ◽  
Hodgkin’S Disease ◽  
Burkitt’S Lymphoma ◽  
Latent Membrane Protein ◽  
Barr Virus ◽  
Infected Cells ◽  
Epstein Barr

Epstein-Barr virus (EBV) infection, prevalent in all human populations, is clinically silent in general, but causes infectious mononucleosis in some adolescents and B-lymphocyte proliferative disorders (LPDs) in immunocompromised individuals (e.g. AIDS infected; allograft recipients). EBV is also etiologically associated with African Burkitt’s lymphoma, nasopharyngeal carcinoma, and Hodgkin’s disease. The virus infects B lymphocytes and transforms them into lymphoblastoid cells which proliferate indefinitely in culture. The latently infected cells express an array of EBV gene products including 6 nuclear antigens (EBNAs), terminal proteins LMP-2A and LMP-2B, latent membrane protein LMP-1, and untranslated RNAs EBER 1 and EBER 2. These components are being extensively studied since they are involved in latency or proliferative transformation; LMP-1 has also shown oncogenic properties. In this work, we have used immunogold electron microscopy for precise subcellular localization of LMP-1 in EBV infected cell lines.Two human cell lines, P3HR-1 (Burkitt’s lymphoma) and CCL-113 (Hodgkin’s disease), obtained from ATCC, were grown in RPMI 1640 containing 20% fetal calf serum, 100 U/ml penicillin and 100 μg/ml streptomycin.

Characterization of epstein-barr virus-infected cells in benign lymphadenopathy of patients seropositive for human immunodeficiency virus

1996 ◽  
Vol 27 (3) ◽  
pp. 263-268 ◽  
Author(s):  
Pierre Brousset ◽  
Daniel Schlaifer ◽  
Daniel Roda ◽  
Patrice Massip ◽  
Bruno Marchou ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Epstein Barr Virus ◽  
Barr Virus ◽  
Immunodeficiency Virus ◽  
Infected Cells ◽  
Epstein Barr

scholarly journals Autorepression of Epstein-Barr Virus Nuclear Antigen 1 Expression by Inhibition of Pre-mRNA Processing

2007 ◽  
Vol 82 (4) ◽  
pp. 1679-1687 ◽  
Author(s):  
Mikio Yoshioka ◽  
Michelle M. Crum ◽  
Jeffery T. Sample
Keyword(s):  
Cell Lines ◽  
Epstein Barr Virus ◽  
Rna Binding ◽  
Cytotoxic T Cells ◽  
Nuclear Antigen ◽  
Genome Maintenance ◽  
Barr Virus ◽  
Latently Infected ◽  
Infected Cells ◽  
Epstein Barr

ABSTRACT Epstein-Barr virus (EBV) latent infection, and its associated oncogenic potential, is dependent on genome maintenance functions of EBV nuclear antigen 1 (EBNA-1), one of six EBNAs expressed from a common promoter (Wp and then Cp) upon infection of naive B cells. Subsequent host-mediated silencing, however, necessitates the expression of EBNA-1 from the EBNA-1-specific promoter Qp to ensure against genome loss during cell division, including EBV-associated malignancy. Here we addressed the mechanism by which EBNA-1 represses Qp through binding downstream of the transcription start site and the role of this autoregulatory function in EBV latency. Our results revealed that EBNA-1 does not inhibit transcription from Qp, as previously predicted, but acts post- or cotranscriptionally to block the processing of primary transcripts. This does not, however, require the RGG motifs responsible for strong but nonspecific RNA binding by EBNA-1. Within isogenic B-cell lines using either Cp/Wp or Qp, EBNA-1 occupancy of Qp is equivalent, suggesting that autoregulation occurs, albeit to different degrees, during full and restricted EBV latency programs. Finally, in cell lines using Cp or Wp for EBNA expression, unprocessed transcripts from Qp are detectable in the absence of corresponding mRNAs, providing further evidence that this novel mechanism of EBNA-1 action functions during latency. This posttranscriptional mechanism of regulation would provide an efficient means to monitor and regulate EBNA-1 expression from Qp, ensuring levels adequate for genome maintenance but, perhaps more importantly, below an immunogenic threshold above which latently infected cells may be at risk for elimination by EBNA-1-specific cytotoxic T cells.

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