Cloning and characterization of androgen receptor coactivator, ARA55, in human prostate
Cloning and characterization of androgen receptor coactivator, ARA55, in human prostate
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DOI：
10.1074/jbc.274.12.8316
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发表时间：
1999-03-19
影响因子：
4.8
通讯作者：
Chang, CS
中科院分区：
文献类型：
--
作者：
Fujimoto, N;Yeh, SY;Chang, CS
雄激素受体（AR）是一种激素激活的转录因子，可以与雄激素反应元件结合，并通过可能涉及辅因子的机制调节靶基因的转录。我们在这里报告了使用酵母双杂交系统克隆新型 AR 共激活剂 ARA55。 ARA55由444个氨基酸组成，预计分子量为55 kDa，其序列与小鼠hic5（一种TGF-β1诱导基因）具有非常高的同源性。酵母和哺乳动物双杂交系统和免疫共沉淀实验均证明ARA55可以以配体依赖性方式与AR结合。前列腺癌 DU145 细胞中的瞬时转染测定进一步表明，在 1 nM 二氢睾酮或其拮抗剂（例如 100 nM 17 β-雌二醇或 1 muM 羟基氟他胺）存在下，ARA55 可以增强 AR 转录活性。我们的数据还表明 ARA55 的 C 端一半（包括三个 LIM 基序）足以与 AR 相互作用。 Northern blot和聚合酶链反应定量显示ARA55在正常前列腺和前列腺肿瘤细胞中表达不同。总之，我们的数据表明，ARA55 可能通过调节 AR 反式激活在前列腺癌的进展中发挥非常重要的作用。
Androgen receptor (AR) is a hormone-activated transcriptional factor that can bind to androgen response elements and that regulates the transcription of target genes via a mechanism that presumably involves cofactors. We report here the cloning of a novel AR coactivator ARA55 using a yeast two-hybrid system. ARA55 consists of 444 amino acids with the predicted molecular mass of 55 kDa and its sequence shows very high homology to mouse hic5, a TGF-beta 1-inducible gene. Yeast and mammalian two-hybrid systems and co immunoprecipitation assays all prove ARA55 can bind to AR in a ligand-dependent manner. Transient transfection assay in prostate cancer DU145 cells further demonstrates that ARA55 can enhance AR transcriptional activity in the presence of 1 nM dihydrotestosterone or its antagonists such as 100 nM 17 beta-estradiol or 1 mu M hydroxyflutamide, Our data also suggest the C-terminal half of ARA55, which includes three LIM motifs, is sufficient to interact with AR. Northern blot and polymerase chain reaction quantitation showed ARA55 can be expressed differently in normal prostate and prostate tumor cells. Together, our data suggests that ARA55 may play very important roles in the progression of prostate cancer by the modulation of AR transactivation.