GLUCOCORTICOID INDUCTION OF THE RAT TRYPTOPHAN OXYGENASE GENE IS MEDIATED BY 2 WIDELY SEPARATED GLUCOCORTICOID-RESPONSIVE ELEMENTS
GLUCOCORTICOID INDUCTION OF THE RAT TRYPTOPHAN OXYGENASE GENE IS MEDIATED BY 2 WIDELY SEPARATED GLUCOCORTICOID-RESPONSIVE ELEMENTS
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DOI：
10.1002/j.1460-2075.1987.tb04800.x
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发表时间：
1987-03-01
期刊：
影响因子：
11.4
通讯作者：
RENKAWITZ, R
中科院分区：
文献类型：
--
作者：
DANESCH, U;GLOSS, B;RENKAWITZ, R
糖皮质激素可诱导大鼠肝脏色氨酸加氧酶（TO）基因转录增加10倍。为了鉴定介导糖皮质激素调节的TO基因表达的DNA元件，我们用融合基因转染小鼠L细胞，所述融合基因由连接到氯霉素乙酰转移酶（CAT）基因的编码序列的1.95 kb TO 5“-侧翼序列组成。CAT分析和RNA定位实验表明，TO-CAT融合基因的瞬时和稳定表达都可被地塞米松诱导。对5“-缺失突变体的转录物的分析鉴定了两个糖皮质激素反应元件（GRE），位于帽位点上游450 bp和1.2 kb。纯化的大鼠糖皮质激素受体结合到每个GRE的序列，从足迹实验证明。有趣的是，近端足迹的受保护序列本身不足以进行序列诱导，而是需要位于紧邻上游的序列。
Transcription of the gene coding for tryptophan oxygenase (TO) in rat liver is induced 10-fold by glucocorticoids. To identify DNA elements mediating the glucocorticoid-regulated expression of the TO gene we transfected mouse L cells with a fusion gene consisting of 1.95 kb TO 5''-flanking sequences linked to the coding sequence of the gene for chloramphenicol acetyltransferase (CAT). CAT assay and RNA mapping experiments demonstrate that both transient and stable expression of the TO-CAT fusion gene are inducible by dexamethasone. Analysis of transcripts from 5''-deletion mutants identifies two glucocorticoid-responsive elements (GRE), located 450 bp and 1.2 kb upstream of the cap site. The purified rat glucocorticoid receptor binds to the sequence of each GRE as evidenced from footprinting experiments. Interestingly the protected sequence of the proximal footprint is by itself not sufficient for sequence induction, but requires sequences located immediately upstream.