雄激素受体配体结合结构域可稳定活细胞中的DNA结合。

The androgen receptor ligand-binding domain stabilizes DNA binding in living cells.

作者信息

Farla Pascal, Hersmus Remko, Geverts Bart, Mari Pierre O, Nigg Alex L, Dubbink Hendrikus J, Trapman Jan, Houtsmuller Adriaan B

机构信息

Department of Pathology, Josephine Nefkens Institute, Erasmus MC, University Medical Center Rotterdam, P.O. Box 1738, 3000 DR Rotterdam, The Netherlands.

出版信息

J Struct Biol. 2004 Jul;147(1):50-61. doi: 10.1016/j.jsb.2004.01.002.

DOI:10.1016/j.jsb.2004.01.002

PMID:15109605

Abstract

The androgen receptor (AR) is a member of the steroid receptor family, a group of transcription factors that activate steroid-regulated genes. Live cell studies of several steroid receptors have shown that the mobility of the liganded receptor is strongly reduced compared to the unliganded receptor. To investigate the nature of this reduced mobility, we generated Hep3B cells stably expressing green fluorescent protein (GFP)-AR at physiological levels. Computer-aided analysis of photobleaching experiments showed that in the presence of ligand on average one out of five ARs is immobilized, each individual AR being immobile for 1-2 min. This immobilization depended on DNA binding since GFP-ARs mutated in the DNA-binding domain were not immobilized. Interestingly, a truncated AR lacking the ligand-binding domain (LBD) displayed substantially shorter immobilizations, in the order of seconds, although its transcriptional activation function was stronger. Our data suggest the LBD has a role in maintaining the stability of AR-DNA complexes.

摘要

雄激素受体（AR）是类固醇受体家族的成员，类固醇受体家族是一组激活类固醇调节基因的转录因子。对几种类固醇受体的活细胞研究表明，与未结合配体的受体相比，结合配体的受体的迁移率大幅降低。为了研究这种迁移率降低的本质，我们构建了在生理水平稳定表达绿色荧光蛋白（GFP）-AR的Hep3B细胞。对光漂白实验的计算机辅助分析表明，在有配体存在的情况下，平均每五个AR中有一个被固定，每个单独的AR固定1-2分钟。这种固定依赖于DNA结合，因为在DNA结合结构域发生突变的GFP-AR没有被固定。有趣的是，一个缺少配体结合结构域（LBD）的截短型AR显示出明显更短的固定时间，约为几秒，尽管其转录激活功能更强。我们的数据表明，LBD在维持AR-DNA复合物的稳定性方面发挥作用。