Interaction of the Mr = 90,000 heat shock protein with the steroid-binding domain of the glucocorticoid receptor.
We have investigated the physiochemical characteristics of trypsin-treated, molybdate-stabilized glucocorticoid-receptor complexes from rat liver in the presence of 10 mM sodium molybdate by high performance ion-exchange chromatography, high performance size-exclusion chromatography, and sedimentation analysis. Trypsin treatment was performed under conditions previously reported to degrade the monomeric Mr approximately 94,000 steroid-binding protein to an Mr approximately 27,000 ligand-binding entity (Wrange, O., and Gustafsson, J.-A. (1978) J. Biol. Chem. 253, 856-865). Also in the presence of molybdate, an Mr approximately 27,000 steroid-binding fragment was obtained by limited trypsinization. However, no major differences in the tested physicochemical parameters were seen when trypsin-treated glucocorticoid-receptor complexes were compared with crude cytosolic complexes. Furthermore, the Mr approximately 27,000 steroid-binding fragment generated in the presence of molybdate could be immunoprecipitated by antibodies specific for the glucocorticoid receptor-associated Mr approximately 90,000 heat shock protein. These results provide direct evidence for an interaction of the Mr approximately 90,000 heat shock protein with the steroid-binding domain of the glucocorticoid receptor, known to correspond to the C-terminal third of the receptor protein.
Denis
M
M
Department of Medical Nutrition, Karolinska Institute, Huddinge University Hospital, Sweden.
Gustafsson
J A
JA
Wikström
A C
AC
D000315:Adrenalectomy; D000818:Animals; D003600:Cytosol / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000302:isolation & purification / Q000378:metabolism*; D014357:Trypsin
D006360:Heat-Shock Proteins; D011965:Receptors, Glucocorticoid; D014357:Trypsin