Binding of activated progesterone receptor to microsomes.
Specific binding of steroid hormones to microsomes has been reported for several tissues. In the hen oviduct, this receptor appears to be very similar to activated cytosolic receptor. The microsomal receptor is readily solubilized, and resembles the cytosolic receptor in all physico-chemical characteristics: sedimentation coefficient approximately 4 S, Stokes radius 5.5 nm, slow dissociation rate of the complex, adsorption to polyanions. It is precipitated by an antibody to the cytosolic receptor. Microsomes display saturable binding of cytosolic receptor, with a Bmax of approximately 300 fmol/mg protein. This binding is also observed using microsomes from non-target tissues, and is decreased by treatment with RNase. It seems likely that microsomal binding is due to the high affinity of activated cytosolic receptor for RNA.
D000818:Animals; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002645:Chickens; D003600:Cytosol / Q000032:analysis; D005260:Female; D007163:Immunosorbent Techniques; D008861:Microsomes / Q000378:metabolism*; D010057:Oviducts / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism; D011980:Receptors, Progesterone / Q000187:drug effects / Q000378:metabolism*; D012260:Ribonucleases / Q000494:pharmacology; D012995:Solubility
D011980:Receptors, Progesterone; D011374:Progesterone; D012260:Ribonucleases