AN S1 NUCLEASE-SENSITIVE HOMOPURINE HOMOPYRIMIDINE DOMAIN IN THE C-KI-RAS PROMOTER INTERACTS WITH A NUCLEAR FACTOR
AN S1 NUCLEASE-SENSITIVE HOMOPURINE HOMOPYRIMIDINE DOMAIN IN THE C-KI-RAS PROMOTER INTERACTS WITH A NUCLEAR FACTOR
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DOI：
10.1073/pnas.87.7.2705
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发表时间：
1990-04-01
影响因子：
11.1
通讯作者：
GEORGE, DL
中科院分区：
文献类型：
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作者：
HOFFMAN, EK;TRUSKO, SP;GEORGE, DL
为了深入了解调节c-ki-ras原癌基因表达的正常对照，我们已经确定了其启动子中对转录活性至关重要的DNA序列元件。利用细菌氯霉素乙酰转移酶基因的瞬时表达分析初步定位了主要启动子功能的区域。5‘’启动子序列的逐步缺失导致报告基因转录驱动能力逐渐降低，提示该启动子由多个顺式作用元件组成。涉及166个碱基对的DNA片段的凝胶迁移率移位和DNA酶保护研究允许识别与这些多个调节元件相对应的蛋白质结合位点。一个显示特殊转录影响的元件存在于高嘌呤/高嘧啶富集区，该区域在体外表现出对S1核酸酶的敏感性，并至少与一种核蛋白结合。来自竞争结合实验的数据表明，这种核因子可能也会对其他重要的生长控制基因的调控产生影响。
To gain insight into the normal controls mediating expression of the c-Ki-ras protooncogene, we have identified DNA sequence elements within its promoter that are essential for transcriptional activity. Transient expression assays using the bacterial chloramphenicol acetyltransferase gene were used initially to localize regions directing primary promoter function. Stepwise deletion of 5'' promoter sequences resulted in a gradual decrease in the ability to drive transcription of the reporter gene, suggesting that this promoter is composed of multiple cis-acting elements. Gel mobility-shift and DNase protection studies involving a 166-base-pair DNA fragment allowed the identification of protein-binding sites corresponding to these multiple regulatory elements. One element demonstrating particular transcriptional influence exists as a homopurine/homopyrimidine-rich region that in vitro exhibits S1 nuclease sensitivity and binds at least one nuclear protein. Data from competition binding experiments suggest that this nuclear factor may be influential in the regulation of other essential growth-control genes as well.