Functional implications of glucocorticoid receptor trafficking.

Abstract

Glucocorticoid hormones affect a variety of cellular processes through their interactions with a soluble intracellular receptor protein, the glucocorticoid receptor (GR). The GR is a member of the nuclear receptor superfamily of ligand-activated transcription factors and regulates the transcriptional activity of a diverse subset of genes via its direct interaction with promoter-linked target sequences or interaction with unique transcription factors (McEwan et al. 1997). In the absence of ligand, GR is located primarily in the cytoplasm in close association with various chaperone proteins, including heat shock protein 90 (hsp90). Upon hormone binding, the hormone-receptor complex becomes activated, forms a homodimer, and moves into the nucleus. For transactivation, the hormone-receptor complex binds to glucocorticoid response elements (GRE) in the promoter region of target genes.