Androgen Receptor

The androgen receptor (AR) (NR3C4, nuclear receptor subfamily 3, group C, gene 4), a ligand-dependent nuclear transcription factor, belongs to the steroid hormone group of nuclear receptors with the estrogen receptor (ER), glucocorticoid receptor (GR), progesterone receptor (PR) and mineralocorticoid receptor (MR). Like other members of the nuclear receptor family, the AR comprises three main functional domains: the N-terminal transcriptional regulation domain, the DNA binding domain (DBD) and the ligand binding domain. The AR is cytoplasmic, associated with heat-shock and other chaperone proteins in the absence of ligand. The interaction of androgens and AR results in a conformational change, dissociation of chaperone proteins and exposure of the NLS (NLS). The androgen/AR complex translocates to the nucleus where it dimerises and binds to AREs within classical target genes to modulate gene transcription. The transcriptional regulatory effects of the AR include pathways involved in cell growth and proliferation, cell cycle progression, protein synthesis, and cell death.