REGULATORY ELEMENTS IN THE 1ST INTRON CONTRIBUTE TO TRANSCRIPTIONAL CONTROL OF THE HUMAN ALPHA-1(I) COLLAGEN GENE
REGULATORY ELEMENTS IN THE 1ST INTRON CONTRIBUTE TO TRANSCRIPTIONAL CONTROL OF THE HUMAN ALPHA-1(I) COLLAGEN GENE
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DOI：
10.1073/pnas.84.24.8869
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发表时间：
1987-12-01
影响因子：
11.1
通讯作者：
GELINAS, RE
中科院分区：
文献类型：
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作者：
BORNSTEIN, P;MCKAY, J;GELINAS, RE
几条证据表明，I型胶原基因转录的调节是复杂的，重要的调节元件位于α 1（I）基因第一内含子的5“处和之内。因此，我们对2.3-内切酶HindIII片段进行了测序，该片段包含α 1（I）人胶原蛋白基因的5 ″侧翼序列、第一外显子和大部分第一内含子的804个碱基对。一个274个碱基对的内含子序列，两侧的Ava I位点（A274），包含一个序列相同的转录因子Sp1和病毒核心增强子序列的高亲和力的癸核苷酸结合位点。DNA酶I保护实验表明，保护区，对应于这些图案。当A274被克隆到氯霉素乙酰转移酶（CAT）基因的5 ″，由α 1（I）胶原启动子序列驱动，并通过转染评估表达时，观察到CAT活性的显著定向特异性抑制。这种作用在鸡腱成纤维细胞中最为明显，其调节培养物中胶原蛋白的合成水平。我们提出α 1（I）胶原基因转录的正常调节是由启动子区和第一内含子内存在的阳性和阴性元件的相互作用引起的。
Several lines of evidence have suggested that the regulation of type I collagen gene transcription is complex and that important regulatory elements reside 5'' to, and within, the first intron of the .alpha.1(I) gene. We therefore sequenced a 2.3-kilobase HindIII fragment that encompasses 804 base pairs of 5'' flanking sequence, the first exon, and most of the first intron of the .alpha.1(I) human collagen gene. A 274-base-pair intronic sequence, flanked by Ava I sites (A274), contained a sequence identical to a high-affinity decanucleotide binding site for transcription factor Sp1 and a viral core enhancer sequence. DNase I protection experiments indicated zones of protection that corresponded to these motifs. When A274 was cloned 5'' to the chloramphenicol acetyltransferase (CAT) gene, driven by an .alpha.1(I) collagen promoter sequence, and expression was assessed by transfection, significant orientation-specific inhibition of CAT activity were observed. This effect was most apparent in chicken tendon fibroblasts, which modulate their level of collagen synthesis in culture. We propose that normal regulation of .alpha.1(I) collagen gene transcription results from an interplay of positive and negative elements present in the promoter region and within the first intron.