FUNCTIONAL CHARACTERIZATIONS OF THE ANDROGEN RECEPTOR CONFIRM THAT THE MOLECULAR-BASIS OF ANDROGEN ACTION IS TRANSCRIPTIONAL REGULATION
FUNCTIONAL CHARACTERIZATIONS OF THE ANDROGEN RECEPTOR CONFIRM THAT THE MOLECULAR-BASIS OF ANDROGEN ACTION IS TRANSCRIPTIONAL REGULATION
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DOI：
10.1210/mend-4-5-708
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发表时间：
1990-05-01
影响因子：
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通讯作者：
MIESFELD, RL
中科院分区：
文献类型：
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作者：
RUNDLETT, SE;WU, XP;MIESFELD, RL
为了了解雄激素在前列腺中作用的分子基础，我们从大鼠腹侧前列腺细胞中分离出雄激素受体（AR）cDNA，并在共转染试验中分析了编码蛋白的转录调控活性。我们发现，AR能够诱导氯霉素乙酰转移酶活性超过20倍，使用小鼠乳腺肿瘤病毒LTR作为雄激素反应元件的来源。在猴CV 1细胞和人HeLa细胞中均观察到这种诱导，这两种细胞均不含内源性功能性AR，并且完全依赖于添加的雄激素。缺失作图研究表明，约250个氨基酸的羧基末端缺失将AR转化为组成型转录激活剂。此外，嵌合受体蛋白的氨基末端和DNA结合域的AR融合到先前定义的糖皮质激素受体的结构域被发现是完全功能的地塞米松诱导的氯霉素乙酰转移酶活性的基础上。我们的研究结果支持雄激素调节转录起始速率的预测，表明雄激素的转录后效应是次级反应。此外，这些数据表明，像其他类固醇受体一样，AR包含许多对正常活动重要的不同调节区域。完全AR序列的分离和表征将有助于使用分子遗传学来研究靶组织（如前列腺）中复杂的雄激素反应。
In an effort to understand the molecular basis of androgen action in the prostate, we isolated androgen receptor (AR) cDNA from rat ventral prostate cells and analyzed the transcriptional regulatory activity of the encoded protein in a cotransfection assay. We found that AR is capable of inducing chloramphenicol acetyltransferase activity more than 20-fold using the mouse mammary tumor virus LTR as a source of androgen response elements. This induction was observed in both monkey CV 1 cells and human HeLa cells, neither of which contains endogenous functional AR, and was entirely dependent on added androgens. Deletion mapping studies showed that carboxy-terminal deletions of .apprx.250 amino acids convert AR into a constitutive activator of transcrition. In addition, a chimeric receptor protein containing the amino-terminus and DNA-binding domains of AR fused to the previously defined domain of the glucocorticoid receptor was found to be fully functional based on dexamethasone-induced chloramphenicol acetyltransferase activity. Our results support the prediction that androgens modulate rates of transcriptional initiation, suggesting that posttranscriptional effects of androgens are secondary responses. Moreover, these data reval that, like other steroid receptors, AR contains a number of distinct regulatory regions important for normal activity. The isolation and characterization of fully AR sequences will facilitate the use of molecular genetics to study complex androgen responses in target tissues such as the prostate.