title: The prosence of estrogen receptor in kidneys from normal and androgen-insensitive tfm/y mice.
abstract: In vitro and in vivo binding of [3H]estradiol to cytosol proteins and nuclei was studied in kidneys from normal and androgen-insensitive tfm/y mice. The use of tfm/y mice permitted study of the estrogen-receptor complex in the absence of androgen receptor. A high affinity, [3H]estradiol-labeled, 8S molecule was demonstrated in low salt sucrose gradients. This macromolecule sedimented more slowly in gradients containing KC1 (0.5 M). Binding of [3H]estradiol was inhibited by 100-fold excess estrone, estradiol, or diethylstillbestrol but was not affected by testosterone, androstenedione, or progesterone. Studies of equilibrium-binding kinetics for estradiol indicated a Kd of 1.4 X 10(-9) M and 4.4 X 10(-14) mol of binding sites/mg cytosol protein. Furthermore, the binder was an acidic, heat-labile protein (pI = 4.8) which could be precipitated from cytosol with 33% ammonium sulfate, and needed sulfhydryl groups for activity. The demonstration of an estradiol-binding protein in vitro was correlated with specific [3H]estradiol uptake by tfm/y kidney nuclei in vivo. We concluded that the mouse kidney contains an estradiol-binding protein, distinct from that for androgens, which has many of the characteristics of a steroid receptor. The presence of an estrogen receptor in both normal and tfm/y mice indicates that a genetic defect in one receptor does not influence the properties of another. We concluded that androgen and estrogen receptors are under independent genetic control.
mesh_terms: D000818:Animals; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004351:Drug Resistance; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D008168:Lung / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D009928:Organ Specificity; D011485:Protein Binding; D011506:Proteins / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000187:drug effects; D013739:Testosterone / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D011506:Proteins; D011956:Receptors, Cell Surface; D013739:Testosterone; D004958:Estradiol