Regulation of Glucocorticoid Receptor Function through Assembly of a Receptor-Heat Shock Protein Complex

• Published in: Annals of the New York Academy of Sciences 1993-06, Vol.684 (1), p.35-48
• Main Authors: HUTCHISON, KEVIN A., SCHERRER, LAWRENCE C., CZAR, MICHAEL J., STANCATO, LOUIS F., CHOW, YU-HUA, JOVE, RICHARD, PRATT, WILLIAM B.
• Format: Article
• Language: English
• Subjects: Animals; Cell Line; DNA - metabolism; DNA-Binding Proteins - metabolism; Heat-Shock Proteins - metabolism; Mice; Rats; Receptors, Glucocorticoid - metabolism; Receptors, Glucocorticoid - physiology
• ISSN: 0077-8923; 1749-6632
• DOI: 10.1111/j.1749-6632.1993.tb32269.x

Incubation of immunopurified, hormone-free mouse glucocorticoid receptors with rabbit reticulocyte lysate results in ATP-dependent and monovalent cation-dependent assembly of the GR into a heterocomplex with hsp90, hsp70, and hsp56. Heterocomplex assembly is accompanied by conversion of the receptor from a form that does not bind steroid to a high affinity steroid-binding conformation. Reticulocyte lysate also promotes ATP-dependent dissociation of unliganded receptors from a prebound receptor-DNA complex. Receptor released from DNA has been reconstituted into the heat shock protein heterocomplex and converted to the non-DNA-binding state. The reticulocyte lysate also reconstitutes pp60v-src into a heterocomplex containing hsp90 and p50, both of which are components of the native heterocomplex form of the tyrosine kinase in cytoplasm. Although the c-Raf-1 serine/threonine kinase has never been found in native association with hsp90, it can be assembled into a heat shock protein heterocomplex by the ATP-dependent system in reticulocyte lysate.