Genomic location and organization of the human glucocorticoid receptor. The human glucocorticoid receptor is located on chromosome 5q31–32 locus. (A) GR undergoes alternative processing to yield multiple functionally distinct subtypes of GR. GR contains 9 exons with the protein coding region formed by exons 2–9. Exon 1 forms the 5’-untranslated region. Alternative splicing of GR generates hGRα and hGRβ isoforms, which differ in their C-termini. (B) The GRα isoform undergoes alternative translation initiation in exon 2, generating eight additional isoforms of GR with truncated N-termini (GRα-A, GRα-B, GRα-C1, GRα-C2, GRα-C3, GRα-D1, GRα-D2, and GRα-D3). GR β is predicted to also generate eight β isoforms similar to hGRα. (C) GR is a modular protein containing an N-terminal transactivation domain (NTD), a central DNA-binding domain (DBD), a C-terminal ligand-binding domain (LBD), and a flexible “hinge region” separating the DBD and the LBD. The NTD has strong transcriptional activation function (AF1), which allows for the recruitment of coregulators and transcription machinery. Glucocorticoids bind the hydrophobic pocket of the LBD causing the second activation function (AF2), located in the LBD itself, to interact with coregulators. The DBD/hinge region junction and the LBD, each contain a nuclear localization signal that allows translocation to the nucleus. (D) GR undergoes multiple posttranslational modifications including phosphorylation (P), SUMOylation (S), ubiquitination (U) and acetylation (A).