IDENTIFICATION OF A CYCLIC-AMP-RESPONSIVE ELEMENT WITHIN THE RAT SOMATOSTATIN GENE
IDENTIFICATION OF A CYCLIC-AMP-RESPONSIVE ELEMENT WITHIN THE RAT SOMATOSTATIN GENE
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DOI：
10.1073/pnas.83.18.6682
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发表时间：
1986-09-01
影响因子：
11.1
通讯作者：
GOODMAN, RH
中科院分区：
文献类型：
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作者：
MONTMINY, MR;SEVARINO, KA;GOODMAN, RH
我们研究了生长抑素基因表达的调节cAMP在PC 12大鼠嗜铬细胞瘤细胞转染大鼠生长抑素基因。在稳定转染的细胞中，10 μ M的毛喉素在处理4小时内引起生长抑素mRNA水平的4倍增加。嵌合基因含有生长抑素基因启动子融合细菌报告基因编码氯霉素乙酰转移酶也诱导cAMP在PC 12细胞。为了描述cAMP应答所需的序列，我们构建了一系列启动子缺失突变体。我们的研究确定了一个区域之间的60和29个碱基对上游的转录起始位点，赋予cAMP的反应时，放置在邻近的猿猴病毒40启动子。在生长抑素基因的cAMP反应元件中，我们观察到一个8碱基回文，5“-TGACGTCA-3”，它在许多其他基因中高度保守，这些基因的表达受cAMP调节。当生长抑素融合基因转染到突变型PC 12细胞系A126- 1B 2中时，cAMP反应性大大降低，该细胞系缺乏cAMP依赖性蛋白激酶2。我们的研究表明，生长抑素基因cAMP的转录调控需要蛋白激酶2的活性，并可能依赖于一个高度保守的启动子元件。
We have examined the regulation of somatostatin gene expression by cAMP in PC12 rat pheochromocytoma cells transfected with the rat somatostatin gene. Forskolin at 10 .mu.M caused a 4-fold increase in somatostatin mRNA levels within 4 hr of treatment in stably transfected cells. Chimeric genes containing the somatostatin gene promoter fused to the bacterial reporter gene encoding chloramphenicol acetyltransferase were also induced by cAMP in PC12 cells. To delineate the seqeunces required for response to cAMP, we constructed a series of promoter deletion mutants. Our studies defined a region between 60 and 29 base pairs upstream from the transcriptional initiation site that conferred cAMP responsiveness when placed adjacent to the simian virus 40 promoter. Within the cAMP-responsive element of the somatostatin gene, we observed an 8-base palindrome, 5''-TGACGTCA-3'', which is highly conserved in many other genes whose expression is regulated by cAMP. cAMP responsiveness was greatly reduced when the somatostatin fusion genes were transfected into the mutant PC12 line A126-1B2, which is deficient in cAMP-dependent protein kinase 2. Our studies indicate that transcriptional regulation of the somatostatin gene cAMP requires protein kinase 2 activity and may depend upon a highly conserved promoter element.