An Epstein-Barr virus transcript from a latently infected, growth-transformed B-cell line encodes a highly repetitive...

By screening a cDNA library prepared from poly(A)+ RNA isolated from an Epstein-Barr virus latently infected, growth-transformed human B-lymphoblastoid cell line, we have recovered a clone corresponding to a highly spliced viral transcript encoded largely by the major internal repeat (IR1). The 5' region contains one copy of a 26-base-pair (bp) exon (W0) [which is 28 bp downstream from a CAATT-(N)34TATAAA sequence (N, unspecified base)] and seven copies of two small exons (W1, 66 bp; W2, 132 bp). In addition, there are three exons from the "unique" region of the BamHI Y fragment of the viral genome. Two other cDNA clones that have been described, corresponding to latent viral transcripts, share homology in their 5' regions with this clone and are clearly divergent at their 3' ends. The cDNA clone described in this paper contains one long open reading frame that extends through the repeat element. In vitro transcription and translation of this open reading frame yielded a 62-kDa polypeptide that could be immunoprecipitated by an Epstein-Barr virus-positive human serum.