Sanchez E R, Meshinchi S, Tienrungroj W, Schlesinger M J, Toft D O, Pratt W B
J Biol Chem. 1987 May 25;262(15):6986-91.
Incubation of molybdate-stabilized L cell cytosol with a monoclonal antibody directed against the 100-kDa glucocorticoid-binding protein causes the immune-specific adsorption to protein A-Sepharose of both the 100-kDa glucocorticoid receptor and the 90-kDa murine heat shock protein (hsp90) (Sanchez, E. R., Toft, D. O., Schlesinger, M. J., and Pratt, W. B. (1985) J. Biol. Chem. 260, 12398-12401). When the glucocorticoid receptor in cytosol is transformed to the DNA-binding state, hsp90 dissociates. In this paper, we show that temperature-mediated dissociation of hsp90 from the receptor is a hormone-dependent event in the same manner as temperature-mediated transformation to the DNA-binding state. In contrast to temperature-mediated transformation, ammonium sulfate causes both dissociation of hsp90 from the receptor and conversion of the receptor to the DNA-binding form in a manner that does not require the presence of steroid. The untransformed form of the glucocorticoid receptor and the strongly negatively charged hsp90 protein behave similarly on DEAE-cellulose chromatography, suggesting that the hsp90 component may contribute significantly to the net negative charge behavior of the non-DNA-binding form of the receptor complex.
用针对100 kDa糖皮质激素结合蛋白的单克隆抗体孵育钼酸盐稳定的L细胞胞质溶胶，会导致100 kDa糖皮质激素受体和90 kDa小鼠热休克蛋白（hsp90）免疫特异性吸附到蛋白A-琼脂糖上（桑切斯，E.R.，托夫特，D.O.，施莱辛格，M.J.，和普拉特，W.B.（1985年）《生物化学杂志》260，12398 - 12401）。当胞质溶胶中的糖皮质激素受体转变为DNA结合状态时，hsp90会解离。在本文中，我们表明，hsp90从受体上的温度介导解离与温度介导的转变为DNA结合状态一样，是一个激素依赖性事件。与温度介导的转变不同，硫酸铵会导致hsp90从受体上解离，同时使受体转变为DNA结合形式，且这种方式不需要类固醇的存在。糖皮质激素受体的未转变形式和带强负电荷的hsp90蛋白在DEAE - 纤维素色谱上表现相似，这表明hsp90组分可能对受体复合物非DNA结合形式的净负电荷行为有显著贡献。
