Heparin-mediated inactivation and transformation of mammary cytoplasmic glucocorticoid receptor.
Glucocorticoid receptor of lactating mouse mammary gland cytosol was exposed to heparin when the receptor was either steroid-free or steroid-bound. Heparin caused a dose-dependent and time-dependent loss of steroid binding activity (inactivation) of the steroid-free receptor; this heparin-induced inactivation was inhibited by molybdate. In contrast, steroid-bound receptor maintained its steroid binding capacity in the presence of heparin but the heparin caused transformation of receptor as detected by increased binding to DNA-cellulose and ATP-Sepharose. Heparin also converted steroid-bound receptor from the 7-8S form to the 4S form. Molybdate inhibited both the heparin-induced transformation and associated conversion to the 4S form.
D000818:Animals; D003600:Cytosol / Q000378:metabolism; D003907:Dexamethasone / Q000378:metabolism; D005260:Female; D006493:Heparin / Q000494:pharmacology*; D007700:Kinetics; D007774:Lactation; D008321:Mammary Glands, Animal / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011247:Pregnancy; D011965:Receptors, Glucocorticoid / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D011987:Receptors, Steroid / Q000378:metabolism*
D011965:Receptors, Glucocorticoid; D011987:Receptors, Steroid; D003907:Dexamethasone; D006493:Heparin