5α-Dihydrotestosterone Binding Protein in Rat Ventral Prostate; Purification, Nuclear Incorporation, and Subnuclear Localization

Treatment of cytosol from the rat ventral prostate with cold acetone (-20°C) evoked a 8-10-fold increase in the binding capacity with 5α-dihydrotestosterone (DHT). Starting from the extract of acetone-dried prostate cytosol, some 400-500-fold purification of the DHT-binding protein complex was achieved by (NH4) 2SO4 fractionation, DEAE-cellulose chromatography and gel-filtration with Sephadex G-200. The purified 3H-DHT-binding protein complex was incorporated into the nuclei from the ventral prostate in a temperature dependent manner. The similar incorporation was also observed in nuclei from the liver and the kidney. Separation of prostate nuclei into subnuclear fractions revealed that the majority of the incorporated 3H-DHT-binding protein complex was located in the fraction of heterochromatin and a relatively small amount of 3H-DHT-binding protein complex was observed in the fraction of nucleolei. A slightly different pattern of distribution of 3H-DHT-binding protein complex among subnuclear fractions was observed in nuclei from rat liver.