Activation of the U2 snRNA promoter by the octamer motif defines a new class of RNA polymerase II enhancer elements.
Activation of the U2 snRNA promoter by the octamer motif defines a new class of RNA polymerase II enhancer elements.
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八聚体基序激活 U2 snRNA 启动子定义了一类新的 RNA 聚合酶 II 增强子元件。
DOI：
10.1101/gad.2.12b.1764
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发表时间：
1988
影响因子：
10.5
通讯作者：
Hernandez,N
中科院分区：
文献类型：
--
作者：
Tanaka,M;Grossniklaus,U;Herr,W;Hernandez,N
最近的发现，转录激活因子（如GAL 4）从一些物种的激活结构域是可互换的，导致了一个一般的RNA聚合酶II基因的激活机制的概念。我们已经研究了SV 40八聚体基序ATGCAAAG在B细胞和HeLa细胞中的不同活性，无论是β-珠蛋白启动子，TATA盒含有mRNA启动子，或U2 snRNA启动子，其中含有snRNA特异性近端元件。在β-珠蛋白启动子的背景下，八聚体基序是B细胞特异性增强子元件，而它是U2 snRNA启动子的普遍存在的增强子元件。U2启动子是独特的，因为它不被激活β-珠蛋白启动子的增强子元件激活，并且含有上游激活序列UASG的杂合U2启动子不被酵母GAL 4反式激活因子激活。总之，这些观察结果表明，在U2启动子的上下文中，八聚体基序定义了一类新的RNA聚合酶II增强子元件，其结合转录因子，所述转录因子通过与上述一般机制不同的机制反式激活基因表达。这些结果进行了讨论的可能性，无处不在的八聚体结合蛋白的Oct-1和B细胞特异性八聚体结合蛋白的Oct-2参与的U2和β-珠蛋白启动子的激活，分别。
The recent discovery that the activation domains of transcriptional activators (eg, GAL4) from a number of species are interchangeable has led to the concept of a general mechanism for activation of RNA polymerase II genes. We have examined the different activities of the SV40 octamer motif ATGCAAAG in B cells and in HeLa cells in the context of either the beta-globin promoter, a TATA-box-containing mRNA promoter, or the U2 snRNA promoter, which contains a snRNA-specific proximal element. In the context of the beta-globin promoter, the octamer motif is a B-cell-specific enhancer element, whereas it is a ubiquitous enhancer element for the U2 snRNA promoter. The U2 promoter is unique in that it is not activated by enhancer elements that activate the beta-globin promoter, and a hybrid U2 promoter containing the upstream activating sequence UASG is not stimulated by a yeast GAL4 trans-activator. Together, these observations suggest that in the context of the U2 promoter, the octamer motif defines a new class of RNA polymerase II enhancer elements, which bind transcription factors that trans-activate gene expression by a different mechanism than the general mechanism mentioned above. These results are discussed in light of the possibility that the ubiquitous octamer binding protein Oct-1 and the B-cell-specific octamer binding protein Oct-2 are involved in the activation of the U2 and beta-globin promoters, respectively.