title: Progesterone receptor in the rat ovary: further characterization and localization in the granulosa cell.
abstract: We have recently described a progesterone receptor in the cytosol of ovaries of hypophysectomized, estrogen-primed, immature rats. This progesterone receptor was shown to be a thermolabile, saturable protein, which is specific for progestins (R5020 and progesterone), and elutes at the void volume of a Sephadex G-200 column. In the present study, we performed a more detailed analysis of the biochemical properties of this receptor and examined its cellular localization within the ovary. Treatment of the ovary cytosol with protamine sulfate and N-ethyl maleimide abolishes the specific binding of 3H-R5020, indicating that the receptor is an acidic protein containing cysteine residues necessary for binding. Gel exclusion chromatography shows the progesterone receptor to have a mean Stokes radius of 86 A and a molecular weight of approximately 300,000 daltons. Kinetic analysis indicates that the receptor--R5020 complex dissociates very rapidly, with a t1/2 of 10 minutes. The cytosol of isolated granulosa cells bind 3H-R5020 specifically, demonstrating that the ovarian progesterone receptor is present in the granulosa cell.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel; D003600:Cytosol / Q000378:metabolism; D005260:Female; D006107:Granulosa Cells / Q000032:analysis*; D007700:Kinetics; D008301:Maleimides / Q000494:pharmacology; D008970:Molecular Weight; D009649:Norpregnadienes / Q000378:metabolism*; D010053:Ovary / Q000032:analysis*; D011397:Promegestone / Q000378:metabolism*; D011479:Protamines / Q000494:pharmacology; D051381:Rats; D011980:Receptors, Progesterone / Q000032:analysis* / Q000378:metabolism
chemical_list: D008301:Maleimides; D009649:Norpregnadienes; D011479:Protamines; D011980:Receptors, Progesterone; D011397:Promegestone