title: EBNA-1, a bifunctional transcriptional activator.
abstract: Transient-transfection assays have been used to identify transcription factors, and genetic analyses of these factors can allow a dissection of their mechanism of activation. Epstein-Barr nuclear antigen 1 (EBNA-1) has been shown to activate transcription from transfected templates, but its ability to activate transcription from nuclear templates has been controversial. We have established cells with integrated EBNA-1-responsive templates and have shown that EBNA-1 activates transcription from these chromatin-embedded templates dose dependently. A mutational analysis of EBNA-1 has identified a domain required for transcriptional activation of integrated templates, but not of transfected templates. The ability of EBNA-1 to activate transcription from both integrated and transfected templates can be inhibited by a derivative of EBNA-1 lacking the amino acids required for activation from integrated templates. EBNA-1's mode of activating transfected templates is therefore genetically distinct from that acting on integrated templates.
authors.affiliation: McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA.
authors.forename: Gregory
authors.initials: G
authors.lastname: Kennedy
authors.forename: Bill
authors.initials: B
authors.lastname: Sugden
mesh_terms: D000595:Amino Acid Sequence; D001402:B-Lymphocytes / Q000378:metabolism / Q000821:virology*; D002461:Cell Line, Transformed; D004261:DNA Replication; D019309:Epstein-Barr Virus Nuclear Antigens / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D005814:Genes, Viral; D004854:Herpesvirus 4, Human / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D013698:Templates, Genetic; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: D019309:Epstein-Barr Virus Nuclear Antigens; D015534:Trans-Activators; C417029:EBV-encoded nuclear antigen 1