Nuclear protein that binds sterol regulatory element of low density lipoprotein receptor promoter. I. Identification of the protein and delineation of its target nucleotide sequence.
Nuclear protein that binds sterol regulatory element of low density lipoprotein receptor promoter. I. Identification of the protein and delineation of its target nucleotide sequence.
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发表时间：
1993-07
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通讯作者：
M. Briggs;C. Yokoyama;Xiaodong Wang;Michael S. Brown;J. Goldstein
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作者：
M. Briggs;C. Yokoyama;Xiaodong Wang;Michael S. Brown;J. Goldstein
本文报道了在大鼠肝细胞核中发现的一种与低密度脂蛋白受体基因启动子中的固醇调节元件(SRE-1)结合的蛋白质。10个碱基对的SRE-1被嵌入一个16个碱基对的重复序列2中，该序列位于相关序列重复3的上游。为了证实SRE-1结合蛋白(SREBP)对DNA的识别与固醇调节的转录相关，我们合成了一个人工启动子，它包含两个拷贝的野生型或突变型重复2+3序列，正好位于腺病毒TATA盒的上游。将合成的启动子插入报告基因的上游，并在瞬时转染猴子CV-1细胞后，在没有和存在甾醇的情况下测试转录活性。报告基因具有两个拷贝的野生型重复序列2+3序列，在没有甾醇的细胞中转录活跃，当有甾醇存在时，报告基因被抑制了80%以上。通过凝胶迁移率改变分析，SREBP与SRE-1序列的结合，在逐个核苷酸的基础上，与16个在重复序列2中有点突变的合成启动子的转录活性精确相关。SREBP与9个固醇调节转录阳性的突变启动子结合，而不与9个取消转录的点突变株结合。我们的结论是，SREBP是一种DNA结合蛋白，介导了固醇调节的低密度脂蛋白受体基因的转录。
The current paper reports the identification of a protein in rat liver nuclei that binds to the sterol regulatory element (SRE-1) in the promoter of the gene for the low density lipoprotein receptor. The 10-base pair SRE-1 is embedded within a 16-base pair sequence designated Repeat 2 located immediately upstream of a related sequence designated Repeat 3. To confirm that DNA recognition by the SRE-1 binding protein (SREBP) correlates with sterol-regulated transcription, we synthesized an artificial promoter that contains two copies of wild-type or mutant Repeat 2 + 3 sequences immediately upstream of a TATA box from adenovirus. The synthetic promoters were inserted upstream of a reporter gene and tested for transcriptional activity in the absence and presence of sterols after transient transfection into monkey CV-1 cells. The reporter gene with two copies of the wild-type Repeat 2 + 3 sequence was transcribed actively in sterol-deprived cells and was repressed by more than 80% when sterols were present. Binding of SREBP to the SRE-1 sequence, assessed by gel mobility shift assays, correlated precisely on a nucleotide-by-nucleotide basis with the transcriptional activity of each of 16 synthetic promoters with point mutations in Repeat 2. The SREBP bound to the nine mutant promoters that were positive for sterol-regulated transcription, and it did not bind to any of the nine point mutants that abolished transcription. We conclude that SREBP is a DNA binding protein that mediates sterol-regulated transcription of the low density lipoprotein receptor gene.