Manet E, Gruffat H, Trescol-Biemont M C, Moreno N, Chambard P, Giot J F, Sergeant A
Laboratoire de Virologie Moléculaire, Ecole Normale Supérieure de Lyon, CNRS (UMR13), France.
EMBO J. 1989 Jun;8(6):1819-26. doi: 10.1002/j.1460-2075.1989.tb03576.x.
The Epstein-Barr virus (EBV) genome codes for several transcriptional trans-activators. One of them, the BZLF1 open reading frame (ORF)-encoded product EB1, is able to induce the productive cycle in infected B cells. From the cloning and characterization of full-length cDNAs, we found that EB1 could be made from three overlapping messenger RNAs expressed under the control of two different promoters that we call P1 and P2. The first mRNA, 1 kb long, is made from the P1 promoter and codes for EB1 alone. The two other mRNAs, respectively 3 and 4 kb long and made by facultative splicing, are bicistronic mRNAs. They code not only for the trans-activator EB1 but also for a second EBV transcriptional trans-activator R, encoded by the BRLF1 ORF. In effect, authentic EB1 and R proteins are expressed from the 3 and 4 kb long cDNAs as demonstrated by identification of the proteins with specific antisera. In addition, EB1 and R expressed from the 3 and 4 kb cDNAs activate transcription from their specific targets in the EBV early promoter DR.
爱泼斯坦-巴尔病毒（EBV）基因组编码几种转录反式激活因子。其中之一，即BZLF1开放阅读框（ORF）编码的产物EB1，能够在受感染的B细胞中诱导增殖周期。通过全长cDNA的克隆和表征，我们发现EB1可由在我们称为P1和P2的两个不同启动子控制下表达的三种重叠信使RNA产生。第一种mRNA长1 kb，由P1启动子产生，仅编码EB1。另外两种mRNA分别长3 kb和4 kb，通过选择性剪接产生，是双顺反子mRNA。它们不仅编码反式激活因子EB1，还编码由BRLF1 ORF编码的第二种EBV转录反式激活因子R。实际上，如通过用特异性抗血清鉴定蛋白质所证明的，真正的EB1和R蛋白从3 kb和4 kb长的cDNA中表达。此外，从3 kb和4 kb cDNA表达的EB1和R激活EBV早期启动子DR中其特定靶标的转录。
