Separate DNA elements containing ATF/CREB and IE86 binding sites differentially regulate the human cytomegalovirus UL112-113 promoter at early and late times in the infection
Separate DNA elements containing ATF/CREB and IE86 binding sites differentially regulate the human cytomegalovirus UL112-113 promoter at early and late times in the infection
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DOI：
10.1128/jvi.72.4.2697-2707.1998
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发表时间：
1998-04-01
影响因子：
5.4
通讯作者：
Spector, DH
中科院分区：
文献类型：
--
作者：
Rodems, SM;Clark, CL;Spector, DH
人巨细胞病毒（HCMV） UL112-113启动子为研究病毒基因表达的时间调控提供了一个有用的模型，86-kDa即刻早期蛋白（IE86）对该启动子的刺激由核苷酸-113和-59之间的序列控制，该序列包括ATF/CREB和IE86结合位点，在瞬态分析中，ATF/CREB位点是必需的，IE86位点虽然不是必需的，但可以增强转录。我们已经在病毒基因组的背景下评估了这些启动子元件的功能。插入的UL112-113启动子的转录表现出与内源性启动子相同的时间模式，包括在感染后期切换到上游RNA起始位点。删除含有IE86位点的序列导致早期转录水平下降和晚期转录消除，相反，当删除ATF/CREB位点时，早期RNA合成几乎完全被取消，但晚期转录与野生型相当，RNA起始位点下游被删除的核苷酸数量重新定位。用来自主要直接早期启动子的HCMV顺式抑制信号替换-108和-95之间的序列对晚期RNA的水平没有影响，但导致RNA起始位点上游39个核苷酸的重新定位。这些结果表明，ATF/CREB位点仅在早期起作用，而包含IE86位点的序列调节早期rna的水平，并以距离依赖的方式激活晚期转录。
The human cytomegalovirus (HCMV) UL112-113 promoter represents a useful model for studying temporal regulation of viral gene expression, Stimulation of this promoter by the 86-kDa immediate-early protein (IE86) is controlled by sequences between nucleotides -113 and -59, which include both an ATF/CREB and an IE86 binding site, In transient assays, the ATF/CREB site is essential, and the IE86 site, although nonessential, can enhance transcription, With recombinant viruses, we have assessed the function of these promoter elements in the context of the viral genome. Transcription from the inserted UL112-113 promoter shows the same temporal pattern as the endogenous promoter, including the switch to an upstream RNA start site Late in infection. Deletion of sequences containing the IE86 site results in a decrease in the Level of early transcription and elimination of late transcription, In contrast, when the ATF/CREB site is deleted, early RNA synthesis is almost completely abolished, but late transcription is comparable to that of the wild type, with repositioning of the RNA start site downstream by the number of nucleotides deleted. Replacement of sequences between -108 and -95 with the HCMV cis-repression signal from the major immediate-early promoter had no effect on the level of late RNAs but resulted in the repositioning of the RNA start site 39 nucleotides upstream. These results suggest that the ATF/CREB site is functional only at early times, while sequences containing the IE86 site modulate the level of early RNAs and map be required for activating late transcription in a distance-dependent manner.