An Epstein-Barr virus nuclear protein 2 domain essential for transformation is a direct transcriptional activator.
Epstein-Barr virus nuclear protein 2 (EBNA-2) increases mRNA levels of specific viral and cellular genes through direct or indirect effects on upstream regulatory elements. The EBNA-2 domains essential for these effects have been partially defined and correlate with domains important for B-cell growth transformation. To determine whether EBNA-2 has a direct transcriptional activating domain, gene fusions between the DNA-binding domain of GAL4 and EBNA-2 were tested in CHO and B-lymphoma cells for the ability to activate transcription from target plasmids containing GAL4 recognition sites upstream of an adenovirus or murine mammary tumor virus promoter. In B-lymphoma cells, a 37-amino-acid EBNA-2 domain previously identified to be essential for transformation was nearly as strong a transcriptional activator as the activating domain of herpes simplex virus trans-inducing factor VP16. A quadradecapeptide had about 25% of the activating activity of the longer peptide. This first evidence that EBNA-2 directly activates transcription should facilitate the identification of nuclear factors with which EBNA-2 interacts in transactivation and transformation.
Cohen
J I
JI
Medical Virology Section, National Institutes of Health, Bethesda, Maryland 20892.
Kieff
E
E
D000818:Animals; D000956:Antigens, Viral / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D016466:CHO Cells; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D019309:Epstein-Barr Virus Nuclear Antigens; D004854:Herpesvirus 4, Human / Q000235:genetics* / Q000276:immunology; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides; D016366:Open Reading Frames; D010957:Plasmids; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D015534:Trans-Activators / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection
D000956:Antigens, Viral; D019309:Epstein-Barr Virus Nuclear Antigens; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D015534:Trans-Activators; D015500:Chloramphenicol O-Acetyltransferase