Steroid hormone receptors and signal transduction processes

Abstract

Steroid hormones, i.e., androgens, estrogens, glucocorticoids, mineralocorticoids, and progestins, bind with high affinity to their respective steroid hormone receptors (SR). SRs are members of a family of nuclear receptors (NR). Ligand-activated SRs dissociate from hsp90 chaperone complexes in the cytoplasm and enter the nucleus where they bind to specific DNA sequences: hormone response elements (HREs). SRs interact with coregulator proteins (coactivators and corepressors) as well as chromatin remodeling complexes to regulate target gene expression. In addition, some SRs are also associated with the plasma membrane (PM) and PM proteins. Hormone binding to PM-associated SRs activates G-protein coupled receptors (GPCR) and intracellular signaling pathways ultimately regulating gene transcription and other downstream sequelae. This chapter will review of SR/NR including protein structure, ligand activation, gene regulation, examples of rapid “non-genomic” signaling, and the roles of these receptors in human health and disease.