Glucocorticoid Receptor Signaling

The glucocorticoid hormone, cortisol, passes through the plasma membrane into the cytoplasm where it binds to the specific, high-affinity glucocorticoid receptor (GR). The resulting complex is the non-DNA-binding oligomer of the GR, in which the receptor is complexed with other proteins. In this complex, the DNA-binding domain of the receptor is bound by the heat shock protein 90 (hsp90) dimer. Other proteins in this complex include heat shock protein 70 (hsp70) and FKBP52. Dissociation of the oligomeric complex yields the free cortisol-receptor subunit in the DNA-binding form. The activated receptor forms a homodimer and is translocated to the nucleus through the nucleopore. Inside the nucleus, the receptor complex binds to specific DNA responsive elements (GRE) to activate gene transcription.

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References:

Bruner, K.L., et al., The unliganded mineralocorticoid receptor is associated with heat shock proteins 70 and 90 and the immunophilin FKBP-52. Recept. Signal Transduct., 7, 85-98 (1997).

Drouin, J., et al., Homodimer formation is rate-limiting for high affinity DNA binding by glucocorticoid receptor. Mol Endocrinol., 6, 1299-1309 (1992).