Regulation of 21-hydroxylase gene expression.-猫眼课题宝

21-羟化酶基因表达的调节。

DOI：

发表时间：

1989

期刊：

Endocrine Research

影响因子：

2.1

通讯作者：

中科院分区：

医学4区

文献类型：

作者：

J. Handler;B. Schimmer;T. R. Flynn;M. Szyf;D. Rice;K. Parker

类固醇21-羟化酶（21-OH）基因选择性地在肾上腺皮质中表达，并受ACTH的转录调节。我们通过分析21-OH的5 '-侧翼序列在转染到Y1小鼠肾上腺皮质肿瘤细胞中后指导人生长激素（hGH）报告基因表达的能力，检查了21-OH的5'-侧翼序列在这种调节表达中的作用。330 bp的5 '-侧翼序列指导Y1细胞中hGH的基础表达和生殖诱导表达，但不指导I-10小鼠睾丸Leydig细胞中的表达。组成型和细胞诱导型表达都需要功能性cAMP依赖性蛋白激酶。这些结果表明，21-OH基因的5 ′侧翼序列的前330 bp含有足够的细胞特异性和神经调节表达的信息，并且这种表达需要cAMP依赖性蛋白激酶的完整性。当将156 bp的5 '-侧翼序列置于报告基因之前时，观察到hGH的表达显著降低，表明-330和-156之间的序列对于表达是必需的。在p-156 GH质粒中以正确或相反方向加入-330至-150的序列，可使启动子活性恢复到大约用330 bp的5 ′-侧翼序列获得的水平。此外，添加-230至-150的序列使由异源胸苷激酶启动子驱动的hGH表达增加5倍。基于这些结果，我们得出结论，增强子元件包含在转录起始位点上游230至150 bp的序列内。

The steroid 21-hydroxylase (21-OH) gene is selectively expressed in the adrenal cortex and is transcriptionally regulated by ACTH. We examined the role of the 5'-flanking sequences of 21-OH in this regulated expression by analyzing their ability to direct the expression of a human growth hormone (hGH) reporter gene upon transfection into Y1 mouse adrenocortical tumor cells. The 330 bp of 5'-flanking sequences directed basal and hormonally-inducible expression of hGH in Y1 cells, but did not direct expression in I-10 mouse testicular Leydig cells. Both constitutive and hormonally-inducible expression required a functional cAMP-dependent protein kinase. These results indicate that the first 330 bp of 5'-flanking sequences of the 21-OH gene contain sufficient information for cell-specific and hormonally regulated expression, and that this expression requires the integrity of cAMP-dependent protein kinase. Markedly lower expression of hGH was seen when 156 bp of 5'-flanking sequences were placed in front of the reporter gene, suggesting that sequences between -330 and -156 are essential for expression. The addition of sequences from -330 to -150 to the p-156GH plasmid, in either the correct or the reverse orientation, restored promoter activity to approximately the level obtained with the 330 bp of 5'-flanking sequences. Moreover, the addition of sequences from -230 to -150 increased by 5-fold the expression of hGH driven by the heterologous thymidine kinase promoter. Based on these results, we conclude that an enhancer element is contained within the sequences from 230 to 150 bp upstream of the transcription initiation site.