Structure and Coding Content of CST (BART) Family RNAs of Epstein-Barr Virus

ABSTRACT CST (BART BARF0) family viral RNAs are expressed in several types of Epstein-Barr virus (EBV) infection, including EBV-associated cancers. Many different spliced forms of these RNAs have been described; here we have clarified the structures of some of the more abundant splicing patterns. We report the first cDNAs representing a full-length CST mRNA from a clone library and further characterize the transcription start. The relative abundance of splicing patterns and genomic analysis of the open reading frames (ORFs) suggest that, in addition to the much studied BARF0 ORF, there may be important products made from some of the upstream ORFs in the CST RNAs. Potential biological functions are identified for two of these. The product of the RPMS1 ORF is shown to be a nuclear protein that can bind to the CBF1 component of Notch signal transduction. RPMS1 can inhibit the transcription activation induced through CBF1 by NotchIC or EBNA-2. The protein product of another CST ORF, A73, is shown to be a cytoplasmic protein which can interact with the cell RACK1 protein. Since RACK1 modulates signaling from protein kinase C and Src tyrosine kinases, the results suggest a possible role for CST products in growth control, perhaps consistent with the abundant transcription of CST RNAs in cancers such as nasopharyngeal carcinoma.

Download Full-text

Microtubule depolymerization activates the Epstein–Barr virus lytic cycle through protein kinase C pathways in nasopharyngeal carcinoma cells

Journal of General Virology ◽

10.1099/vir.0.058040-0 ◽

2013 ◽

Vol 94 (12) ◽

pp. 2750-2758 ◽

Cited By ~ 8

Author(s):

Yi-Ru Liu ◽

Sheng-Yen Huang ◽

Jen-Yang Chen ◽

Lily Hui-Ching Wang

Keyword(s):

Protein Kinase C ◽

Life Cycle ◽

Protein Kinase ◽

Nasopharyngeal Carcinoma ◽

Epstein Barr Virus ◽

Lytic Cycle ◽

Barr Virus ◽

Kinase C ◽

Epstein Barr ◽

In Cells

Elevated levels of antibodies against Epstein–Barr virus (EBV) and the presence of viral DNA in plasma are reliable biomarkers for the diagnosis of nasopharyngeal carcinoma (NPC) in high-prevalence areas, such as South-East Asia. The presence of these viral markers in the circulation suggests that a minimal level of virus reactivation may have occurred in an infected individual, although the underlying mechanism of reactivation remains to be elucidated. Here, we showed that treatment with nocodazole, which provokes the depolymerization of microtubules, induces the expression of two EBV lytic cycle proteins, Zta and EA-D, in EBV-positive NPC cells. This effect was independent of mitotic arrest, as viral reactivation was not abolished in cells synchronized at interphase. Notably, the induction of Zta by nocodazole was mediated by transcriptional upregulation via protein kinase C (PKC). Pre-treatment with inhibitors for PKC or its downstream signalling partners p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) abolished the nocodazole-mediated induction of Zta and EA-D. Interestingly, the effect of nocodazole, as well as colchicine and vinblastine, on lytic gene expression occurred only in NPC epithelial cells but not in cells derived from lymphocytes. These results establish a novel role of microtubule integrity in controlling the EBV life cycle through PKC and its downstream pathways, which represents a tissue-specific mechanism for controlling the life-cycle switch of EBV.

Download Full-text

Induction of Id1 and Id3 by Latent Membrane Protein 1 of Epstein-Barr Virus and Regulation of p27/Kip and Cyclin-Dependent Kinase 2 in Rodent Fibroblast Transformation

Journal of Virology ◽

10.1128/jvi.78.24.13470-13478.2004 ◽

2004 ◽

Vol 78 (24) ◽

pp. 13470-13478 ◽

Cited By ~ 62

Author(s):

David N. Everly ◽

Bernardo A. Mainou ◽

Nancy Raab-Traub

Keyword(s):

Membrane Protein ◽

Epstein Barr Virus ◽

Kinase Inhibitors ◽

Genomic Analysis ◽

Latent Membrane Protein ◽

Mitogen Activated Protein Kinase ◽

Latent Membrane Protein 1 ◽

Cyclin Dependent Kinase ◽

Barr Virus ◽

Epstein Barr

ABSTRACT Latent membrane protein 1 (LMP1), the Epstein-Barr virus oncoprotein, activates NF-κB, phosphatidylinositol 3-kinase, mitogen-activated protein kinase, and c-Jun N-terminal kinase signaling. To determine global transcriptional changes induced by LMP1 in epithelial cells, genomic analysis of C33A cells stably expressing LMP1 was performed. Relatively few genes were induced by LMP1. Expression of two members of the Id (inhibitor of differentiation) family of proteins, Id1 and Id3, was induced in the presence of LMP1 and confirmed by mRNA and protein in C33A and Rat-1 cells. In Rat-1 foci transformed by LMP1, Id1 protein was also increased. Id proteins are known negative regulators of E-box proteins that positively regulate p16 and potentially other cyclin-dependent kinase inhibitors (cdki's). In LMP1-expressing Rat-1 cells, cdki p27 was specifically downregulated. Decreased p27 was correlated with increased levels of Cdk2 and increased levels of phosphorylated retinoblastoma protein. This study describes new properties of LMP1 that likely contribute to transformation and oncogenesis.

Download Full-text

Effect of Protein Kinase C Inhibitors with Different Action Mechanisms on Epstein-Barr Virus Replication

Intervirology ◽

10.1159/000150254 ◽

1992 ◽

Vol 33 (4) ◽

pp. 217-224 ◽

Cited By ~ 5

Author(s):

Kyoko Hayashi

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Virus Replication ◽

Epstein Barr Virus ◽

Protein Kinase C Inhibitors ◽

Barr Virus ◽

Action Mechanisms ◽

Kinase C ◽

Epstein Barr

Download Full-text

Identification of Protein Tyrosine Kinases Required for B-Cell- Receptor-Mediated Activation of an Epstein-Barr Virus Immediate-Early Gene Promoter

Journal of Virology ◽

10.1128/jvi.78.16.8543-8551.2004 ◽

2004 ◽

Vol 78 (16) ◽

pp. 8543-8551 ◽

Cited By ~ 7

Author(s):

Sandra Lavens ◽

Emmanuel A. Faust ◽

Fang Lu ◽

Michele Jacob ◽

Messele Leta ◽

...

Keyword(s):

Signal Transduction ◽

B Cell ◽

Tyrosine Kinases ◽

Epstein Barr Virus ◽

Cell Receptor ◽

Lytic Cycle ◽

Protein Tyrosine Kinases ◽

Early Gene ◽

Barr Virus ◽

Epstein Barr

ABSTRACT Epstein-Barr Virus (EBV) is a potentially oncogenic herpesvirus that infects >90% of the world's population. EBV exists predominantly as a latent infection in B lymphocytes, with periodic lytic-cycle reactivation essential for cellular and host transmission. Viral reactivation can be stimulated by ligand-induced activation of B-cell-receptor (BCR)-coupled signaling pathways. The critical first step in the transition from latency to the lytic cycle is the expression of the viral immediate-early gene BZLF1 through the transcription activation of its promoter, Zp. However, the BCR-coupled signal transduction cascade(s) leading to the induction of Zp and the expression of the BZLF1 gene product, Zta, is currently unclear. A major obstacle to delineating the relevant signal transduction events has been the lack of a model of EBV infection that is amenable to genetic manipulation. The use of the avian B-cell line DT40 has proven to be a powerful tool for delineating BCR-mediated signal transduction pathways that appear to be highly conserved between avian and mammalian systems. We demonstrate that the DT40 cell line is a robust and genetically tractable system for the study of BCR-mediated signaling pathways leading to transcriptional activation of BZLF1. Using this system, we demonstrate that activation of Zp requires the BCR-coupled protein tyrosine kinases Syk and Btk and that it is positively regulated by Lyn. Thus, the use of DT40 cells has allowed us to delineate the early signaling components required for BCR-dependent reactivation of latent EBV, and this system is likely to prove useful for further dissection of the downstream signaling cascades involved.

Download Full-text

Integrative profiling of Epstein–Barr virus transcriptome using a multiplatform approach

Virology Journal ◽

10.1186/s12985-021-01734-6 ◽

2022 ◽

Vol 19 (1) ◽

Author(s):

Ádám Fülöp ◽

Gábor Torma ◽

Norbert Moldován ◽

Kálmán Szenthe ◽

Ferenc Bánáti ◽

...

Keyword(s):

Epstein Barr Virus ◽

Open Reading Frames ◽

Integrative Approach ◽

Splice Isoforms ◽

Sequencing Platform ◽

Barr Virus ◽

Pacific Biosciences ◽

Sequencing Technologies ◽

Long Read ◽

Epstein Barr

Abstract Background Epstein–Barr virus (EBV) is an important human pathogenic gammaherpesvirus with carcinogenic potential. The EBV transcriptome has previously been analyzed using both Illumina-based short read-sequencing and Pacific Biosciences RS II-based long-read sequencing technologies. Since the various sequencing methods have distinct strengths and limitations, the use of multiplatform approaches have proven to be valuable. The aim of this study is to provide a more complete picture on the transcriptomic architecture of EBV. Methods In this work, we apply the Oxford Nanopore Technologies MinION (long-read sequencing) platform for the generation of novel transcriptomic data, and integrate these with other’s data generated by another LRS approach, Pacific BioSciences RSII sequencing and Illumina CAGE-Seq and Poly(A)-Seq approaches. Both amplified and non-amplified cDNA sequencings were applied for the generation of sequencing reads, including both oligo-d(T) and random oligonucleotide-primed reverse transcription. EBV transcripts are identified and annotated using the LoRTIA software suite developed in our laboratory. Results This study detected novel genes embedded into longer host genes containing 5′-truncated in-frame open reading frames, which potentially encode N-terminally truncated proteins. We also detected a number of novel non-coding RNAs and transcript length isoforms encoded by the same genes but differing in their start and/or end sites. This study also reports the discovery of novel splice isoforms, many of which may represent altered coding potential, and of novel replication-origin-associated transcripts. Additionally, novel mono- and multigenic transcripts were identified. An intricate meshwork of transcriptional overlaps was revealed. Conclusions An integrative approach applying multi-technique sequencing technologies is suitable for reliable identification of complex transcriptomes because each techniques has different advantages and limitations, and the they can be used for the validation of the results obtained by a particular approach.

Download Full-text

Expression of Epstein-Barr Virus BamHI-A Rightward Transcripts in Latently Infected B Cells From Peripheral Blood

Blood ◽

10.1182/blood.v93.9.3026.409k28_3026_3032 ◽

1999 ◽

Vol 93 (9) ◽

pp. 3026-3032 ◽

Cited By ~ 7

Author(s):

Honglin Chen ◽

Paul Smith ◽

Richard F. Ambinder ◽

S. Diane Hayward

Keyword(s):

B Cells ◽

Peripheral Blood ◽

Epstein Barr Virus ◽

Open Reading Frames ◽

Viral Gene ◽

Barr Virus ◽

Restricted Form ◽

Latently Infected ◽

Epstein Barr

In addition to the Epstein-Barr virus (EBV) EBNA and LMP latency genes, there is a family of alternatively spliced BamHI-A rightward transcripts (BARTs). These latency transcripts are highly expressed in the EBV-associated malignancies nasopharyngeal carcinoma and Burkitt’s lymphoma, and are expressed at lower levels in latently EBV-infected B-cell lines. The contribution of the BARTs to EBV biology or pathogenesis is unknown. Resting B cells have recently been recognized as a reservoir for EBV persistence in the peripheral blood. In these cells, EBV gene expression is tightly restricted and the only viral gene known to be consistently expressed is LMP2A. We used cell sorting and reverse-transcriptase polymerase chain reaction (RT-PCR) to examine whether BARTs are expressed in the restricted form of in vivo latency. Our results demonstrated that RNAs with splicing diagnostic for transcripts containing the BART RPMS1 and BARFO open-reading frames (ORFs) were expressed in CD19+ but not in CD23+ B cells isolated from peripheral blood of healthy individuals. The product of the proximal RPMS1 ORF has not previously been characterized. The RPMS1 ORF was shown to encode a 15-kD protein that localized to the nucleus of transfected cells. Expression of the BARTs in peripheral blood B cells suggests that the proteins encoded by these transcripts are likely to be important for maintenance of in vivo latency.

Download Full-text

Roles of Epstein-Barr virus BGLF3.5 gene and two upstream open reading frames in lytic viral replication in HEK293 cells

Virology ◽

10.1016/j.virol.2015.04.007 ◽

2015 ◽

Vol 483 ◽

pp. 44-53 ◽

Cited By ~ 8

Author(s):

Takahiro Watanabe ◽

Kenshiro Fuse ◽

Takahiro Takano ◽

Yohei Narita ◽

Fumi Goshima ◽

...

Keyword(s):

Viral Replication ◽

Epstein Barr Virus ◽

Open Reading Frames ◽

Hek293 Cells ◽

Barr Virus ◽

Upstream Open Reading Frames ◽

Epstein Barr ◽

Reading Frames

Download Full-text

Latent Membrane Protein 2A of Epstein-Barr Virus Binds WW Domain E3 Protein-Ubiquitin Ligases That Ubiquitinate B-Cell Tyrosine Kinases

Molecular and Cellular Biology ◽

10.1128/mcb.20.22.8526-8535.2000 ◽

2000 ◽

Vol 20 (22) ◽

pp. 8526-8535 ◽

Cited By ~ 117

Author(s):

Gösta Winberg ◽

Liudmila Matskova ◽

Fu Chen ◽

Pamela Plant ◽

Daniela Rotin ◽

...

Keyword(s):

Membrane Protein ◽

B Cell ◽

Tyrosine Kinases ◽

Epstein Barr Virus ◽

Ubiquitin Ligases ◽

Latent Membrane Protein ◽

Ww Domains ◽

Barr Virus ◽

B Cell Signaling ◽

Epstein Barr

ABSTRACT The latent membrane protein (LMP) 2A of Epstein-Barr virus (EBV) is implicated in the maintenance of viral latency and appears to function in part by inhibiting B-cell receptor (BCR) signaling. The N-terminal cytoplasmic region of LMP2A has multiple tyrosine residues that upon phosphorylation bind the SH2 domains of the Syk tyrosine kinase and the Src family kinase Lyn. The LMP2A N-terminal region also has two conserved PPPPY motifs. Here we show that the PPPPY motifs of LMP2A bind multiple WW domains of E3 protein-ubiquitin ligases of the Nedd4 family, including AIP4 and KIAA0439, and demonstrate that AIP4 and KIAA0439 form physiological complexes with LMP2A in EBV-positive B cells. In addition to a C2 domain and four WW domains, these proteins have a C-terminal Hect catalytic domain implicated in the ubiquitination of target proteins. LMP2A enhances Lyn and Syk ubiquitination in vivo in a fashion that depends on the activity of Nedd4 family members and correlates with destabilization of the Lyn tyrosine kinase. These results suggest that LMP2A serves as a molecular scaffold to recruit both B-cell tyrosine kinases and C2/WW/Hect domain E3 protein-ubiquitin ligases. This may promote Lyn and Syk ubiquitination in a fashion that contributes to a block in B-cell signaling. LMP2A may potentiate a normal mechanism by which Nedd4 family E3 enzymes regulate B-cell signaling.

Download Full-text

Complete Nucleotide Sequence of the Rhesus Lymphocryptovirus: Genetic Validation for an Epstein-Barr Virus Animal Model

Journal of Virology ◽

10.1128/jvi.76.1.421-426.2002 ◽

2002 ◽

Vol 76 (1) ◽

pp. 421-426 ◽

Cited By ~ 91

Author(s):

Pierre Rivailler ◽

Hua Jiang ◽

Young-gyu Cho ◽

Carol Quink ◽

Fred Wang

Keyword(s):

Animal Model ◽

Epstein Barr Virus ◽

Interleukin 10 ◽

Open Reading Frames ◽

Gene Repertoire ◽

Barr Virus ◽

Viral Glycoproteins ◽

Epstein Barr ◽

Stimulating Factor ◽

Reading Frames

ABSTRACT We sequenced the rhesus lymphocryptovirus (LCV) genome in order to determine its genetic similarity to Epstein-Barr virus (EBV). The rhesus LCV encodes a repertoire identical to that of EBV, with 80 open reading frames, including cellular interleukin-10, bcl-2, and colony-stimulating factor 1 receptor homologues and an equivalent set of viral glycoproteins. The highly conserved rhesus LCV gene repertoire provides a unique animal model for the study of EBV pathogenesis.

Download Full-text