Mapping of genes in BamHI fragment M of Epstein-Barr virus DNA that may determine the fate of viral infection

Abstract

We used nuclease digestion to map RNA transcripts encoded in the BamHI M fragment of the Epstein-Barr virus (EBV) genome (strain B95-8). Of the five RNAs, three are rightwardly transcribed, have different cap sites but common 3' termini, and are unspliced. The two remaining RNAs are leftwardly transcribed and are 5' and 3' coterminal. One of these transcripts is spliced, resulting in the removal of a small intron from the 5' region of this RNA. We have previously published data which indicated that the BamHI M region is the first actively transcribed region of the viral genome during the replicative cycle, suggesting that one or more genes in this region is important in the initiation of EBV replication. We have now mapped two large EcoRI restriction fragments which span approximately 75% of the P3HR-1 defective genome and which contain DNA from the BamHI M region of the standard genome. The data indicate that only the coding and 5' flanking sequences for the leftwardly transcribed RNAs are intact within the defective genome. Fewer than 500 bases coding for the 3'-most regions of the rightwardly transcribed RNAs are intact, and it is unlikely that these encode functional native polypeptides. Therefore, it seems that transcriptional activation of the BamHI M-region genes is not mediated directly by the rearrangement of M genes in defective P3HR-1 EBV.

Characterization of a cDNA clone corresponding to a transcript from the Epstein-Barr virus BamHI M fragment: evidence for overlapping mRNAs

“…3. These results are in good agreement with Si nuclease mapping experiments for the marmoset cell line B95-8 (20). In both the IB4 and B95-8 cell lines there are three transcripts which map to the left part of the BamHI M fragment: a 3.5-kb message spanning BaRF1, BMRF1, and BMRF2; a 2.5-kb message containing BMRF1 and BMRF2; and a small 1.5-kb message containing only BMRF2.…”

Epstein–Barr virus strains and variations: Geographic or disease‐specific variants?

“…EBV genome contains multiple copies of a 3-kb BamHI-W repeat sequence [Baer et al, 1984;Allan and Rowe, 1989]. Each sequence carries a promoter (Wp) that activates the expression of EBNA-LP and EBNA2 and the W1W2 exons which encode for the active domain of EBNA-LP, thus being important for EBV-associated transformation [Sample et al, 1986;Tierney et al, 2011]. The number of repeats is thought to be functionally important since the number repeats may influence the potential of cell transformation [Tierney et al, 2011].…”

Mta Has Properties of an RNA Export Protein and Increases Cytoplasmic Accumulation of Epstein-Barr Virus Replication Gene mRNA

“…The adjacent convergent mRNA is that for BSLF2/BMLF1 (Mta). The polyadenylation site for this transcript has been mapped to the sequence coincident with the terminus of the BMLF1 ORF (67). An equivalent 853-base RNA that covered the 3Ј 174 bases of the BMLF1 ORF and the region between the BMLF1 and BMRF2 ORFs was also generated to represent a primary Mta transcript.…”