title: Redefining the Epstein-Barr virus-encoded nuclear antigen EBNA-1 gene promoter and transcription initiation site in group I Burkitt lymphoma cell lines.
abstract: The Epstein-Barr virus-encoded nuclear antigen EBNA-1 gene promoter for the restricted Epstein-Barr virus (EBV) latency program operating in group I Burkitt lymphoma (BL) cell lines was previously identified incorrectly. Here we present evidence from RACE (rapid amplification of cDNA ends) cloning, reverse transcription-PCR, and S1 nuclease analyses, which demonstrates that the EBNA-1 gene promoter in group I BL cell lines is located in the viral BamHI Q fragment, immediately upstream of two low-affinity EBNA-1 binding sites. Transcripts initiated from this promoter, referred to as Qp, have the previously reported Q/U/K exon splicing pattern. Qp is active in group I BL cell lines but not in group III BL cell lines or in EBV immortalized B-lymphoblastoid cell lines. In addition, transient transfection of Qp-driven reporter constructs into both an EBV-negative BL cell line and a group I BL cell line gave rise to correctly initiated transcripts. Inspection of Qp revealed that it is a TATA-less promoter whose architecture is similar to the promoters of housekeeping genes, suggesting that Qp may be a default promoter which ensures EBNA-1 expression in cells that cannot run the full viral latency program. Elucidation of the genetic mechanism responsible for the EBNA-1-restricted program of EBV latency is an essential step in understanding control of viral latency in EBV-associated tumors.
mesh_terms: D000956:Antigens, Viral / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D002051:Burkitt Lymphoma / Q000235:genetics*; D003001:Cloning, Molecular; D016172:DNA Fingerprinting; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D018274:Electroporation; D019309:Epstein-Barr Virus Nuclear Antigens; D005091:Exons; D006801:Humans; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012326:RNA Splicing; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured
chemical_list: D000956:Antigens, Viral; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D019309:Epstein-Barr Virus Nuclear Antigens