Functional analysis of cis-acting DNA sequences controlling transcription of the human type I collagen genes.
Functional analysis of cis-acting DNA sequences controlling transcription of the human type I collagen genes.
复制标题
DOI：
10.1016/s0021-9258(19)38305-x
复制
发表时间：
1990-08
期刊：
影响因子：
--
通讯作者：
S. Boast;M. Su;F. Ramirez;M. Sánchez;E. Avvedimento
中科院分区：
文献类型：
--
作者：
S. Boast;M. Su;F. Ramirez;M. Sánchez;E. Avvedimento
位于人前α 2（I）胶原基因转录起始位点上游的3500个碱基对区域含有细胞特异性转录所需的所有序列。在瞬时表达试验中，前-α 2（I）胶原启动子指导生产高水平的细菌氯霉素乙酰转移酶的胶原生产的人胎儿成纤维细胞。另一方面，在不产生胶原蛋白的永生化淋巴母细胞提取物中几乎检测不到酶活性。缺失实验将人启动子的活性区段缩小到相对于转录起始位点包含在核苷酸-376和-108之间的遗传学保守序列。在类似的分析中，前α 1（I）胶原基因未能指导细胞特异性转录。作为这项研究的一部分，围绕在人类前-α 1（I）胶原基因的第一个内含子中假定的增强子元件的争议问题也被重新考虑。因此，我们现在提出了一个更严格的定义，这种顺式作用的DNA元件，因为它的行动是发挥在一个方向优选的方式，并具有很强的特异性，其自身的启动子。此外，刺激似乎不是组织特异性的。最后，证据支持的概念，虽然结构不同，明显安排，I型胶原基因的调控序列可能会结合类似的反式作用因子。
The 3500-base pair region located immediately upstream of the transcriptional start site of the human pro-alpha 2(I) collagen gene contains all the sequences necessary for cell-specific transcription. In transient expression assays, the pro-alpha 2(I) collagen promoter directed the production of high levels of bacterial chloramphenicol acetyltransferase in collagen-producing human fetal fibroblasts. Enzyme activity, on the other hand, was nearly undetectable in extracts from collagen-nonproducing immortalized lymphoblasts. Deletion experiments narrowed the active segment of the human promoter to a phylogenetically conserved sequence comprised between nucleotides-376 and -108, relative to the initiation site of transcription. In similar analyses, the pro-alpha 1(I) collagen gene failed to direct cell-specific transcription. As part of this study, the controversial issue surrounding the putative enhancer element in the first intron of the human pro-alpha 1(I) collagen gene also has been reconsidered. Accordingly, we now propose a more restricted definition of this cis-acting DNA element since its action is exerted in an orientation-preferred manner and with a strong specificity for its own promoter. Moreover, stimulation does not appear to be tissue-specific. Finally, evidence is presented supporting the notion that although structurally different and distinctly arranged, the regulatory sequences of the type I collagen genes may bind similar trans-acting factors.