Epstein-Barr virus latent messages with shuffled leader exons: remnants of circumgenomic transcription?
Epstein-Barr virus latent messages with shuffled leader exons: remnants of circumgenomic transcription?
复制标题
带有改组的前导外显子的 Epstein-Barr 病毒潜在信息：环基因组转录的残余物？
DOI：
10.1128/jvi.69.2.1050-1058.1995
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Rowe,DT
中科院分区：
文献类型：
--
作者：
Qu,L;Rowe,DT
在EB病毒永生化的潜伏感染的B淋巴细胞中有活性的EBNA转录单位覆盖172-kb基因组的约60%。由于基因组作为环状双链DNA分子存在于潜伏感染的细胞中，因此可以想象在转录过程中会产生完整的拷贝。我们没有尝试直接检测巨大的RNA分子，而是使用RNA-PCR来检测前导外显子以改组顺序并入mRNA。在自发性淋巴母细胞样细胞系、限制性表型BL细胞系Wanyanyi和Wewak 2以及B 95 -8、Raji和Akata细胞的多聚腺苷酸化RNA组分中，检测到下游U前导外显子剪接在内部重复前导外显子W1和W2的上游。定量竞争性RNA-PCR显示，U外显子的EBNA 1信息的U外显子改组的领导人的信息的比例约为10：1，与大的变化，从细胞系到细胞系，并不受诱导的裂解周期在B 95 -8，Raji，或Akata细胞。具有改组外显子的信息仅包含C2 W1选择性剪接，其不产生用于EBNA 4基因表达的起始AUG甲硫氨酸密码子。结果为长距离外显子跳跃提供了证据，并暗示基因组长度的转录物可能会发生并参与潜伏期的病毒基因表达。
The EBNA transcription unit which is active in Epstein-Barr virus-immortalized latently infected B lymphocytes covers approximately 60% of the 172-kb genome. Since the genome exists as a circular double-stranded DNA molecule in latently infected cells, it is conceivable that complete copies are made during transcription. Rather than attempt to detect gigantic RNA molecules directly, we used RNA-PCR to detect incorporation of leader exons into mRNA in a shuffled order. The downstream U leader exon was detected spliced upstream of the internal repeat leader exons W1 and W2 in the polyadenylated RNA fraction of spontaneous lymphoblastoid cell lines, restricted phenotype BL cell lines Wanyanyi and Wewak2, and in B95-8, Raji, and Akata cells. Quantitative competitive RNA-PCR showed that the ratio of U exon-containing EBNA1 messages to U exon-shuffled leader messages was approximately 10:1, with large variation from cell line to cell line, and was not affected by induction of the lytic cycle in B95-8, Raji, or Akata cells. Messages with shuffled exons contained only the C2W1 alternative splice, which does not produce an initiator AUG methionine codon for EBNA4 gene expression. The results provide evidence for long-range exon skipping and imply that genome-length transcripts may occur and participate in viral gene expression in latency.