MULTIPLE FUNCTIONAL MOTIFS IN THE CHICKEN U1 RNA GENE ENHANCER
MULTIPLE FUNCTIONAL MOTIFS IN THE CHICKEN U1 RNA GENE ENHANCER
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DOI：
10.1128/mcb.7.12.4185
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发表时间：
1987-12-01
影响因子：
5.3
通讯作者：
STUMPH, WE
中科院分区：
文献类型：
--
作者：
ROEBUCK, KA;WALKER, RJ;STUMPH, WE
鸡U1 RNA基因表达的DNA序列的要求已被检查在卵母细胞转录系统。U1 RNA基因有效表达所需的增强子区域包含在转录起始位点上游跨越核苷酸位置-230至-183的保守DNA序列区域内。这些DNA序列可以被分成至少两个不同的亚区或结构域，它们协同作用以提供大于20倍的U1 RNA合成刺激。第一结构域含有八聚体序列。ATGCAAAT，并承认的DNA结合因子存在于HeLa细胞提取物。第二个结构域（SPH结构域）由紧邻八聚体下游的保守序列组成，并且是增强子的必需组分。在卵母细胞中，SPH结构域的DNA序列能够在没有八聚体结构域的情况下增强基因表达至少10倍。相比之下，八聚体结构域，虽然需要完整的U1 RNA基因的活性，不能刺激表达的情况下，相邻的下游DNA序列。这些发现表明，八聚体的3“位序列在鸡U1 RNA基因增强子的功能中起主要作用。这一概念得到了转录竞争研究的支持，其中克隆的鸡U4 B RNA基因被用于竞争卵母细胞中的限制性转录因子。脊椎动物核小RNA基因增强子的一个普遍特征是具有多种顺式连接结构的多序列基序。
The DNA sequence requirements of chicken U1 RNA gene expression have been examined in an oocyte transcription system. An enhancer region, which was required for efficient U1 RNA gene expression, is contained within a region of conserved DNA sequences spanning nucleotide positions -230 to -183, upstream of the transcriptional initiation site. These DNA sequences can be divided into at least two distinct subregions or domains that acted synergistically to provide a greater than 20-fold stimulation of U1 RNA synthesis. The first domain contains the octamer sequence. ATGCAAAT and was recognized by a DNA-binding factor present in HeLa cell extracts. The second domain (the SPH domain) consists of conserved sequences immediately downstream of the octamer and is an essential component of the enhancer. In the oocyte, the DNA sequences of the SPH domain were able to enhance gene expression at least 10-fold in the absence of the octamer domain. In contrast, the octamer domain, although required for full U1 RNA gene activity, was unable to stimulate expression in the absence of the adjacent downstream DNA sequences. These findings imply that sequences 3'' of the octamer play a major role in the function of the chicken U1 RNA gene enhancer. This concept was supported by transcriptional competition studies in which a cloned chicken U4B RNA gene was used to compete for limiting transcription factors in oocytes. Multiple sequence motifs that can function in a variety of cis-linked configurations may be a general feature of vertebrate small nuclear RNA gene enhancers.