Langley E, Zhou Z X, Wilson E M
Laboratory for Reproductive Biology, University of North Carolina, Chapel Hill 27599, USA.
J Biol Chem. 1995 Dec 15;270(50):29983-90. doi: 10.1074/jbc.270.50.29983.
Domain interactions of the human androgen receptor (AR) dimer were investigated using a protein-protein interaction assay in which the NH2- and carboxyl-terminal regions of human AR were fused to the Saccharomyces cerevisiae GAL4 DNA-binding domain and herpes simplex virus VP16 transactivation domain to produce chimeric proteins. Transcriptional activation of a GAL4 luciferase reporter vector up to 100-fold was greater than Fos/Jun leucine zipper binding, indicating stable AR interaction between AR NH2-terminal residues 1-503 and steroid-binding domain residues 624-919 that was specific for and dependent on androgen binding to the steroid-binding domain and was inhibited by anti-androgen binding. Deletion mutagenesis within the NH2-terminal region indicated transactivation domain residues 142-337 were not required for dimerization, whereas deletions near the NH2 terminus (delta 14-150) or NH2-terminal to the DNA-binding domain (delta 339-499) reduced or eliminated the AR interaction, respectively. An NH2-/NH2-terminal interaction was also observed, but no interaction was detected between ligand-free or bound steroid-binding domains. The results indicate that high affinity androgen binding promotes interactions between the NH2-terminal and steroid-binding domains of human AR, raising the possibility of an androgen-induced anti-parallel AR dimer.
使用蛋白质-蛋白质相互作用分析方法研究了人雄激素受体（AR）二聚体的结构域相互作用，其中将人AR的氨基末端和羧基末端区域分别与酿酒酵母GAL4 DNA结合结构域和单纯疱疹病毒VP16反式激活结构域融合，以产生嵌合蛋白。GAL4荧光素酶报告载体的转录激活比Fos/Jun亮氨酸拉链结合高100倍，这表明AR氨基末端残基1-503与类固醇结合结构域残基624-919之间存在稳定的AR相互作用，这种相互作用对雄激素与类固醇结合结构域的结合具有特异性且依赖于此，并且会被抗雄激素结合所抑制。氨基末端区域内的缺失诱变表明，反式激活结构域残基142-337对于二聚化不是必需的，而氨基末端附近的缺失（δ14-150）或DNA结合结构域氨基末端的缺失（δ339-499）分别减少或消除了AR相互作用。还观察到了氨基末端/氨基末端相互作用，但在无配体或结合配体的类固醇结合结构域之间未检测到相互作用。结果表明，高亲和力的雄激素结合促进了人AR氨基末端和类固醇结合结构域之间的相互作用，增加了雄激素诱导的反平行AR二聚体形成的可能性。
