EBNA-1: a virally induced nuclear antigen of primate lymphocytes and its expression in Drosophila cells.

EBNA-1 is a nuclear antigen of lymphocytes infected by Epstein-Barr virus and whose size polymorphism correlates only with the strain of infecting virus and the length of the glycine-alanine copolymer encoded by the third internal repeat of the viral genome. The major antigenic determinant(s) also appear to reside in this region. We have been able to obtain efficient expression of this nuclear antigen in cultured Drosophila cells transfected with a cosmid carrying the EBNA-1 coding region, indicating that insect mechanisms recognise control sequences and transcripts of the herpes virus. The association of a vimertin-like protein of mol. wt. 46,000 with Drosophila cell nuclei has been found to vary with culture conditions and heat shock. We now find that the level and nuclear association of this protein also increase after transfection with either EBNA-1 or yolk protein DNA.