Functional characterization of the human hypoxanthine phosphoribosyltransferase gene promoter: evidence for a negative regulatory element.
Functional characterization of the human hypoxanthine phosphoribosyltransferase gene promoter: evidence for a negative regulatory element.
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人次黄嘌呤磷酸核糖基转移酶基因启动子的功能特征：负调控元件的证据。
DOI：
10.1128/mcb.11.8.4157-4164.1991
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发表时间：
1991
影响因子：
5.3
通讯作者：
Patel,PI
中科院分区：
文献类型：
--
作者：
Rincón-Limas,DE;Krueger,DA;Patel,PI
次黄嘌呤磷酸核糖基转移酶（HPRT）催化嘌呤碱基次黄嘌呤和鸟嘌呤的代谢补救。我们以前的特点的基因组结构的humanHPRT基因和描述其启动子序列。在本报告中，我们通过将不同的5 ′-侧翼序列连接到细菌氯霉素乙酰转移酶基因上，鉴定了人HPRT基因的顺式作用转录控制区。相对于翻译起始位点的位置-219至-122的序列是该基因最大表达所需的，并且其在正常和反向方向上的功能相同。此外，在位置-570至-388之间的区域中存在起酸作用的负性元素。该负元件还可以抑制异源基因的启动子，例如腺苷脱氨酶和二氢叶酸还原酶的启动子，其在结构和功能上与人HPRT启动子相似。此外，这种阻遏元件的功能独立于其方向，但似乎是距离依赖性的。体内竞争实验表明，与该负性元件结合的反式作用因子特异性抑制人HPRT启动子活性。两者合计，这些数据localizecis-作用序列在人类HPRT基因表达的调节中很重要，应该允许蛋白质-DNA相互作用的研究，调节该基因的转录。
The enzyme hypoxanthine phosphoribosyltransferase (HPRT) catalyzes the metabolic salvage of the purine bases hypoxanthine and guanine. We previously characterized the genomic structure of the humanHPRTgene and described its promoter sequence. In this report, we identifycis-acting transcriptional control regions of the humanHPRTgene by linking various5′-flanking sequences to the bacterial chloramphenicol acetyltransferase gene. The sequence from positions —219 to —122 relative to the translation initiation site is required for maximal expression of this gene, and it functions equally in both normal and reverse orientations. In addition, acis-acting negative element is present in the region spanning from positions —570 to —388. This negative element can also repress promoters of heterologous genes, such as those of adenosine deaminase and dihydrofolate reductase, which are structurally and functionally similar to the human HPRT promoter. Furthermore, this repressor element functions independently of its orientation but appears to be distance dependent. In vivo competition assays demonstrated that thetrans-acting factor(s) that binds to this negative element specifically inhibits human HPRT promoter activity. Taken together, these data localizecis-acting sequences important in the regulation of humanHPRTgene expression and should allow the study of protein-DNA interactions which modulate the transcription of this gene.