Activation of [3H]estradiol--and [3H]H1285-receptor complexes: effect of salt versus ATP on molybdate-stabilized estrogen receptors.
The activation by salt or ATP of [3H]estradiol- and [3H]H1285-receptor complexes from rabbit uterus and their binding capacity to DNA-cellulose, phosphocellulose and ATP-Sepharose has been studied. The estrogen-receptor was prepared in 1 mM molybdate which stabilized the receptor; but both salt- and ATP-transformation of estrogen receptors occurred. The binding of molybdate-stabilized cytosol [3H]estradiol-receptor complexes to the various resins revealed that salt-activation by 0.3 M KCl caused the greatest binding (5-6-fold) to DNA-cellulose as compared to other resins. However, 5 mM ATP-dependent activation of receptor-complexes resulted in preferential binding to ATP-Sepharose. Activated cytosol [3H]H1285-receptor complexes bound all the resins to a lesser degree when compared to [3H]estradiol-receptor complexes. Partially purified receptor complexes also showed different resin-binding patterns for salt- and ATP-mediated activation. These findings suggest that salt-activation is different than ATP-activation. Further, the differential magnitude of [3H]estradiol- and [3H]H1285-receptor activation suggests that estrogen-receptor complexes are "fully" activated as compared to "partially" activated antiestrogen-receptor complexes.
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D004958:Estradiol / Q000378:metabolism*; D005260:Female; D007700:Kinetics; D008982:Molybdenum / Q000494:pharmacology*; D009994:Osmolar Concentration; D011189:Potassium Chloride / Q000494:pharmacology*; D011817:Rabbits; D011960:Receptors, Estrogen / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D012116:Resins, Plant; D013629:Tamoxifen / Q000031:analogs & derivatives* / Q000378:metabolism; D014599:Uterus / Q000378:metabolism*
D011960:Receptors, Estrogen; D012116:Resins, Plant; D013629:Tamoxifen; D004958:Estradiol; D011189:Potassium Chloride; C039305:H 1285; D008982:Molybdenum; D000255:Adenosine Triphosphate; C024687:sodium molybdate(VI)