Chinpaisal C, Chang L, Hu X, Lee C H, Wen W N, Wei L N
Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
Biochemistry. 1997 Nov 18;36(46):14088-95. doi: 10.1021/bi971598z.
The mouse orphan nuclear receptor TR2-11-f suppressed the expression of reporters fused to a hormone response element of the mouse cellular retinoic acid-binding protein I gene promoter. TR2-11-f was able to bind to a direct repeat with four nucleotides in the spacer (5'TGACCTTTGGGGACCT3') located within this hormone response element as homodimers. The specificity of protein-DNA interactions was demonstrated by competition in gel retardation and antibody-mediated supershift reactions. The residues critical for TR2-11-f binding were mapped to both repeated sequences, whereas the spacer and the flanking sequences were less important. The Kd and Bmax of TR2-11-f homodimer binding to this direct repeat were determined to be 2.6 nM and 0.012 nM, respectively. By using a yeast two-hybrid system, it was demonstrated that dimerization of TR2-11-f was mediated by its ligand-binding domain. The actions of TR2-11-f in regulating cellular retinoic acid-binding protein I gene will likely influence retinoic action and availability within the cells.
小鼠孤儿核受体TR2-11-f抑制了与小鼠细胞视黄酸结合蛋白I基因启动子的激素反应元件融合的报告基因的表达。TR2-11-f能够以同二聚体的形式与位于该激素反应元件内的间隔区有四个核苷酸的直接重复序列（5'TGACCTTTGGGGACCT3'）结合。蛋白质-DNA相互作用的特异性通过凝胶阻滞竞争和抗体介导的超迁移反应得以证明。对TR2-11-f结合至关重要的残基定位于两个重复序列，而间隔区和侧翼序列的重要性较低。TR2-11-f同二聚体与该直接重复序列结合的解离常数（Kd）和最大结合量（Bmax）分别测定为2.6 nM和0.012 nM。通过酵母双杂交系统证明，TR2-11-f的二聚化由其配体结合结构域介导。TR2-11-f在调节细胞视黄酸结合蛋白I基因方面的作用可能会影响细胞内视黄酸的作用和可用性。
