Structure of the glucocorticoid receptor in intact cells in the absence of hormone.
The nonactivated glucocorticoid receptor (Mr approximately 330,000, Strokes radius = 82 A) contained in cell extracts and complexed with a steroidal ligand was previously investigated by chemical cross-linking. It was identified as a heterotetramer composed of one receptor polypeptide, two molecules of the 90-kDa heat shock protein hsp90, and one 59-kDa protein subunit (Rexin, M., Busch, W., and Gehring, U. (1991) J. Biol. Chem. 266, 24601-24605). We now have used the cross-linking technique to investigate the receptor structure in intact WEHI-7 mouse lymphoma cells at 37 degrees C and under steroid-free conditions. Using immunochemical methods we show that the receptor present in whole cells likewise exists as a high molecular weight structure of Strokes radius 82 A. It has a subunit composition identical to that of the nonactivated receptor-steroid complex in cell extracts. This is the first account of a steroid hormone receptor in its native state as it is contained in target cells under physiological conditions and before a hormonal signal is received.
Rexin
M
M
Institut für Biologische Chemie, Universität Heidelberg, Germany.
Busch
W
W
Segnitz
B
B
Gehring
U
U
D000818:Animals; D002460:Cell Line; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D008223:Lymphoma; D046911:Macromolecular Substances; D051379:Mice; D008970:Molecular Weight; D011487:Protein Conformation; D011965:Receptors, Glucocorticoid / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D014407:Tumor Cells, Cultured
D046911:Macromolecular Substances; D011965:Receptors, Glucocorticoid