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The Epstein-Barr virus major latent promoter Qp is constitutively active, hypomethylated, and methylation sensitive.
J Virol. 1998 Sep; 72(9):7075-83.JV

Abstract

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is indispensable for viral DNA replication and episome maintenance in latency. Four promoters, Cp, Wp, Qp, and Fp, are known to drive EBNA1 expression. Here we show that the TATA-less Qp is constitutively active in a variety of EBV-positive [EBV(+)] tumors and cell lines, irrespective of the activities of other EBNA1 promoters, the type of viral latency, and the cell type. The transcription of highly regulated promoters such as the EBV Cp is known to be directly regulated by CpG methylation. To characterize the role of CpG methylation in the regulation of the constitutively active Qp, we performed bisulfite genomic sequencing and functional analyses using a methylation cassette transcriptional reporter assay. Twenty consecutive CpG sites (16 proximal to the Qp initiation site and 4 upstream of the adjacent Fp initiation site) were studied by bisulfite sequencing of DNA extracted from EBV(+) tumors and cell lines. Eighteen EBV(+) tumors of lymphoid (B, T, and NK cell) or epithelial origin and five Burkitt's lymphoma cell lines were studied. The 16 CpG sites proximal to Qp were virtually all unmethylated, but the 4 CpG sites upstream of the Fp initiation site were variably methylated. The methylation cassette assay showed that in vitro methylation of the Qp cassette (-172 to +32) resulted in strong repression of Qp activity in transient transfection. Thus, Qp is susceptible to repression by methylation but was found to be consistently hypomethylated and expressed in all tumors and tumor-derived cell lines studied.

Authors+Show Affiliations

Oncology Center, Johns Hopkins School of Medicine, Baltimore, Maryland, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

9696800

Citation

Tao, Q, et al. "The Epstein-Barr Virus Major Latent Promoter Qp Is Constitutively Active, Hypomethylated, and Methylation Sensitive." Journal of Virology, vol. 72, no. 9, 1998, pp. 7075-83.
Tao Q, Robertson KD, Manns A, et al. The Epstein-Barr virus major latent promoter Qp is constitutively active, hypomethylated, and methylation sensitive. J Virol. 1998;72(9):7075-83.
Tao, Q., Robertson, K. D., Manns, A., Hildesheim, A., & Ambinder, R. F. (1998). The Epstein-Barr virus major latent promoter Qp is constitutively active, hypomethylated, and methylation sensitive. Journal of Virology, 72(9), 7075-83.
Tao Q, et al. The Epstein-Barr Virus Major Latent Promoter Qp Is Constitutively Active, Hypomethylated, and Methylation Sensitive. J Virol. 1998;72(9):7075-83. PubMed PMID: 9696800.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - The Epstein-Barr virus major latent promoter Qp is constitutively active, hypomethylated, and methylation sensitive. AU - Tao,Q, AU - Robertson,K D, AU - Manns,A, AU - Hildesheim,A, AU - Ambinder,R F, PY - 1998/8/8/pubmed PY - 1998/8/8/medline PY - 1998/8/8/entrez SP - 7075 EP - 83 JF - Journal of virology JO - J. Virol. VL - 72 IS - 9 N2 - Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is indispensable for viral DNA replication and episome maintenance in latency. Four promoters, Cp, Wp, Qp, and Fp, are known to drive EBNA1 expression. Here we show that the TATA-less Qp is constitutively active in a variety of EBV-positive [EBV(+)] tumors and cell lines, irrespective of the activities of other EBNA1 promoters, the type of viral latency, and the cell type. The transcription of highly regulated promoters such as the EBV Cp is known to be directly regulated by CpG methylation. To characterize the role of CpG methylation in the regulation of the constitutively active Qp, we performed bisulfite genomic sequencing and functional analyses using a methylation cassette transcriptional reporter assay. Twenty consecutive CpG sites (16 proximal to the Qp initiation site and 4 upstream of the adjacent Fp initiation site) were studied by bisulfite sequencing of DNA extracted from EBV(+) tumors and cell lines. Eighteen EBV(+) tumors of lymphoid (B, T, and NK cell) or epithelial origin and five Burkitt's lymphoma cell lines were studied. The 16 CpG sites proximal to Qp were virtually all unmethylated, but the 4 CpG sites upstream of the Fp initiation site were variably methylated. The methylation cassette assay showed that in vitro methylation of the Qp cassette (-172 to +32) resulted in strong repression of Qp activity in transient transfection. Thus, Qp is susceptible to repression by methylation but was found to be consistently hypomethylated and expressed in all tumors and tumor-derived cell lines studied. SN - 0022-538X UR - https://www.unboundmedicine.com/medline/citation/9696800/The_Epstein_Barr_virus_major_latent_promoter_Qp_is_constitutively_active_hypomethylated_and_methylation_sensitive_ L2 - http://jvi.asm.org/cgi/pmidlookup?view=long&pmid=9696800 DB - PRIME DP - Unbound Medicine ER -