Regulation of expression of the Epstein-Barr virus BamHI-A rightward transcripts.
The Epstein-Barr virus (EBV) BamHI-A rightward transcripts, or BARTs, are a family of mRNAs expressed in all EBV latency programs, including EBV-infected B cells in healthy carriers. Despite their ubiquitous expression, the regulation and biological function of BARTs are still unclear. In this study, the BART 5' termini were characterized by using a procedure that selects capped, full-length mRNAs. Two TATA-less promoter regions, designated P1 and P2, were mapped. P1 had relatively high basal activity in both epithelial and B cells, whereas P2 exhibited higher activity in epithelial cells. Upon EBV infection of B cells, transcription from P1 was detected soon after infection, while expression from P2 was delayed. Promoter-reporter assays in transiently transfected cells revealed that P1 and P2 were differentially regulated. Interferon regulatory factor 7 (IRF7) and IRF5 negatively regulated P1 activity. c-Myc and C/EBP family members positively regulated P2. Regulation of P2 by C/EBPs was characterized by electrophoretic mobility shift assay, chromatin immunoprecipitation, and reporter assays. More-abundant BART expression in epithelial cells correlated with the relative expression of positive and negative regulators in these cells.
Chen
Honglin
H
Department of Microbiology, The University of Hong Kong, Hong Kong.
Huang
Jian
J
Wu
Frederick Y
FY
Liao
Gangling
G
Hutt-Fletcher
Lindsey
L
Hayward
S Diane
SD
D001402:B-Lymphocytes / Q000821:virology; D001483:Base Sequence; D002460:Cell Line; D015245:Deoxyribonuclease BamHI / Q000378:metabolism*; D004847:Epithelial Cells / Q000821:virology; D015967:Gene Expression Regulation, Viral; D006367:HeLa Cells / Q000821:virology; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D014158:Transcription, Genetic
D015245:Deoxyribonuclease BamHI