Late gene expression from the Epstein-Barr virus BcLF1 and BFRF3 promoters does not require DNA replication in cis.
Late gene expression from the Epstein-Barr virus BcLF1 and BFRF3 promoters does not require DNA replication in cis.
复制标题
Epstein-Barr 病毒 BcLF1 和 BFRF3 启动子的晚期基因表达不需要顺式 DNA 复制。
DOI：
10.1128/jvi.71.11.8726-8734.1997
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发表时间：
1997
影响因子：
5.4
通讯作者：
Miller,G
中科院分区：
文献类型：
--
作者：
Serio,TR;Kolman,JL;Miller,G
晚期基因表达跟随并依赖于病毒基因组的裂解复制。尽管缺乏实验证据，但裂解病毒DNA复制被认为可以从基因组中移除修饰或结合因子，这些修饰或结合因子在潜伏期或裂解早期周期中用于抑制晚期基因的表达。我们已经开发了一种报告试验，以开始表征调控EB病毒(EBV)晚期基因表达的机制。在这个模型系统中，在裂解周期的不同阶段，瞬时转染表达EBV的组织培养细胞后，检测晚期启动子-报告融合的活性。该系统忠实地概括了内源性病毒的晚期表达模式，暗示了特定的顺式活性序列在控制晚期基因表达中的作用。此外，这些启动子只对病毒的即刻-早期反式激活因子斑马产生间接反应。这种间接反应是由裂解级联中斑马下游的其他病毒或病毒诱导的活动介导的。在这个系统中，晚期基因表达对病毒DNA聚合酶的抑制剂如磷酸很敏感，尽管报告缺乏真核复制来源，并且在检测条件下不复制。因此，转录模板的复制不是晚期动力学表达的先决条件，这一发现与目前假设裂解的EBV DNA复制和晚期基因表达之间存在顺式活性关系的模型不一致。相反，对这一系统的分析揭示了晚期基因表达和病毒DNA复制之间的反式关系，并突出了这两个事件之间的间接和复杂联系。
Late gene expression follows and is dependent upon lytic replication of the viral genome. Although experimental evidence is lacking, lytic viral DNA replication is believed to remove modifications or binding factors from the genome which serve to repress late gene expression during latency or the early lytic cycle. We have developed a reporter assay to begin characterizing the mechanisms that regulate late gene expression in Epstein-Barr virus (EBV). In this model system, the activities of late promoter-reporter fusions are measured following transient transfection into tissue culture cells expressing EBV during different stages of the lytic cycle. This system faithfully recapitulates late expression patterns from the endogenous virus, implicating specific cis-active sequences in the control of late gene expression. In addition, these promoters respond only indirectly to the viral immediate-early transactivator, ZEBRA. This indirect response is mediated by other viral or virally induced activities downstream of ZEBRA in the lytic cascade. In this system, late gene expression is sensitive to inhibitors of the viral DNA polymerase such as phosphonoacetic acid, although the reporters lack a eukaryotic origin of replication and are not replicated under the assay conditions. Thus, replication of the transcriptional template is not a prerequisite for expression with late kinetics, a finding inconsistent with the current models which posit a cis-active relationship between lytic EBV DNA replication and late gene expression. Rather, analysis of this system has revealed a trans relationship between late gene expression and viral DNA replication and highlights the indirect and complex link between these two events.