Kinetic pulse-chase labeling study of the glucocorticoid receptor in mouse lymphoma cells. Effect of glucocorticoid and antiglucocorticoid hormones on intracellular receptor half-life.
A kinetic pulse-chase labeling technique was used to measure the intracellular half-life of the glucocorticoid receptor in S49 mouse lymphoma cells. Cells were pulse-labeled with [35S]methionine for 30 min and then cultured in the presence of unlabeled methionine (chase). Labeled receptors were quantitated at periodic time points during the chase by immunoadsorption to protein A-Sepharose using the BuGR2 monoclonal antireceptor antibody. The decay of labeled receptors during the chase was linear on a semilog plot, consistent with first order kinetics. Receptor half-life was 9 h when cells were cultured in either phenol red-containing medium supplemented with fetal calf serum or in phenol red free-medium supplemented with charcoal extracted serum, indicating that endogenous steroids do not affect receptor half-life. Receptor half-life was also unchanged when cells were cultured in the presence of 0.1 microM dexamethasone, a glucocorticoid hormone, or 0.1 microM RU486 (11 beta-(4-dimethylamino-phenyl)-17 beta-hydroxy-17 alpha-(propynylestra-4,9- diene-3-one), an antiglucocorticoid hormone. We conclude that the intracellular half-life of the glucocorticoid receptor in S49 mouse lymphoma cells is not regulated by either glucocorticoid or antiglucocorticoid hormones.
Distelhorst
C W
CW
Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106.
Howard
K J
KJ
D000818:Animals; D000911:Antibodies, Monoclonal / Q000502:physiology; D003600:Cytosol / Q000378:metabolism*; D003907:Dexamethasone / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D004963:Estrenes / Q000494:pharmacology; D006207:Half-Life; D007700:Kinetics; D008223:Lymphoma / Q000378:metabolism*; D051379:Mice; D015735:Mifepristone; D011965:Receptors, Glucocorticoid / Q000187:drug effects / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D004963:Estrenes; D011965:Receptors, Glucocorticoid; D015735:Mifepristone; D003907:Dexamethasone