The role of sulfhydryl groups in permitting transformation and DNA binding of the glucocorticoid receptor.

作者：W Tienrungroj, Soheil Meshinchi, Edwin R. Sánchez, Sean E. Pratt, Joseph F. Grippo, Arne Holmgren, William B. Pratt · 发表于：Journal of Biological Chemistry · 年份：1987 · DOI：10.1016/s0021-9258(18)48192-6 · 被引用次数：65 · 研究领域：Hormonal Regulation and Hypertension、Estrogen and related hormone effects、Stress Responses and Cortisol

Treatment of rat liver cytosol containing temperature-transformed, [3H]dexamethasone-bound receptors at 0 degree C with the sulfhydryl-modifying reagent methyl methanethiosulfonate (MMTS) inhibits the DNA-binding activity of the receptor, and DNA-binding activity is restored after addition of dithiothreitol (DTT). When cytosol containing untransformed receptors is heated at 25 degrees C in the presence of MMTS, the 90-kDa heat shock protein dissociates from the receptor in the same manner as in the absence of MMTS, and the receptor will bind to DNA-cellulose if DTT is added subsequently at 0 degree C. These observations are consistent with the conclusion of Bodwell et al. (Bodwell, J. E., Holbrook. N. J. and Munck, A. (1984) Biochemistry 23, 1392-1398) that sulfhydryl moieties on the receptor are absolutely required for the receptor to bind to DNA, and they show that the sulfhydryl-modifying reagent does not inhibit the temperature-mediated dissociation of the heteromeric receptor complex that accompanies transformation to the DNA-binding state. When steroid-receptor complexes that are prebound to DNA-cellulose are exposed to MMTS, the steroid rapidly dissociates, but the receptor remains bound to DNA. Thus, the presence of steroid is not required for the receptor to remain bound to DNA in a high affinity manner. Treatment of cytosol containing transformed glucocorticoid-receptor complexes at 0 degrees C with 20 mM hydrogen peroxide also inactivates the DNA-binding activity o...