Involvement of a non-hormone-binding 90-kilodalton protein in the nontransformed 8S form of the rabbit uterus progesterone receptor.
Nontransformed 8S progesterone receptor (8S-PR) was purified by hormone-specific affinity chromatography from rabbit uterine low-salt cytosol containing 20 mM molybdate. In the eluate obtained with radioactive progestin, sodium dodecyl sulfate-polyacrylamide electrophoresis (SDS-PAGE) showed the presence of several bands, including three that corresponded to approximately 90-, approximately 120-, and approximately 85-kDa proteins. None of these three proteins was found in the eluate of the affinity column when the molybdate-containing cytosol was chromatographed in the presence of nonradioactive progesterone ("mock purification"). Subsequent purification of the affinity eluate by DEAE-Sephacel chromatography gave a single radioactive receptor peak at 0.15 M KCl (approximately 20% yield, 19% purity on the basis of one binding site per approximately 100 kDa) with a sedimentation coefficient of 8.5 S. Silver staining after SDS-PAGE revealed that this purified 8S-PR fraction contained mainly the 120-, 90-, and 85-kDa proteins. [3H]R5020-labeled 8S-PR purified by DEAE-Sephacel column chromatography was UV irradiated, and after SDS-PAGE the 120- and 85-kDa proteins were revealed, but the 90-kDa protein was not.(ABSTRACT TRUNCATED AT 250 WORDS)
D000818:Animals; D002846:Chromatography, Affinity; D003600:Cytosol / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D007700:Kinetics; D046911:Macromolecular Substances; D008970:Molecular Weight; D011374:Progesterone / Q000378:metabolism; D011817:Rabbits; D011980:Receptors, Progesterone / Q000302:isolation & purification / Q000378:metabolism*; D014599:Uterus / Q000378:metabolism*
D046911:Macromolecular Substances; D011980:Receptors, Progesterone; D011374:Progesterone