Evidence for cell-specific regulation of transcription of the rat alpha2A-adrenergic receptor gene.
Evidence for cell-specific regulation of transcription of the rat alpha2A-adrenergic receptor gene.
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大鼠 α2A 肾上腺素受体基因转录的细胞特异性调节的证据。
DOI：
10.1161/01.hyp.27.4.1018
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Gavras,H
中科院分区：
文献类型：
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作者：
Handy,DE;Gavras,H
我们研究了大鼠α 2A-肾上腺素能受体基因的-131到-92区域的转录活性。在HT 29细胞中，该区域对转录具有积极影响，而在RINm 5 F细胞中，该区域对转录具有消极影响。-131到-92区域有一个GC盒（GGGGCGG），周围是重叠的GGAGG重复序列。为了分析与该区域结合的核因子，我们在GGAGG重复序列、GC盒或这两个区域中进行了一系列序列替换。凝胶迁移率变动分析表明，野生型−131/−92序列与HT 29或RINm 5 F提取物之间形成的大多数核因子复合物对识别GC盒的Sp1或相关蛋白具有特异性。GGAGG重复序列或GC盒的突变都没有消除Sp1或相关核因子的结合，这表明GGAGG重复序列和GC盒都可以结合Sp1相关因子。这两个位点的突变消除了Sp1相关因子的结合。在没有Sp1结合位点的情况下，该区域对HT 29中的转录有负面影响，对RINm 5 F细胞中的转录有正面影响。这些数据支持Sp1和/或相关因子可能控制正性和负性基因表达的观点，并表明−131/−92区域可能参与调节α 2A肾上腺素能受体基因表达的组织特异性水平。
We investigated the transcriptional activity of the −131 to −92 region of the rat α2A-adrenergic receptor gene. In HT29 cells, this region has a positive effect on transcription, whereas in RINm5F cells, this region has a negative effect on transcription. The −131 to −92 region has a GC box (GGGGCGG) surrounded by overlapping GGAGG repeats. To analyze nuclear factor binding to this region, we made a series of sequence substitutions in the GGAGG repeats, the GC box, or both regions. Gel mobility shift assays indicated that most of the nuclear factor complexes formed between the wild-type −131/−92 sequence and either HT29 or RINm5F extracts were specific for Sp1 or related proteins that recognize a GC box. Mutation of either the GGAGG repeats or the GC box did not eliminate the binding of Sp1 or related nuclear factors, suggesting that both the GGAGG repeats and the GC box could bind Sp1-related factors. Mutation of both these sites eliminated the binding of Sp1-related factors. In the absence of Sp1 binding sites, this region had a negative effect on transcription in HT29 and a positive effect on transcription in RINm5F cells. These data support the notion that Sp1 and/or a related factor may control both positive and negative gene expression and suggest that the −131/−92 region may be involved in regulating tissue-specific levels of α2A-adrenergic receptor gene expression.