Glucocorticoid receptor

Nuclear receptor subfamily 3, group C, member 1 (glucocorticoid receptor)
Crystallographic structures of the glucocorticoid receptor DNA binding domain (DBD, left, PDB: 1R4O​ bound to DNA) and ligand binding domain [LBD, right, 1M2Z bound to dexamethasone (white sticks) and the TIF2 coactivator protein (red)]. Dashed yellow lines represent hydrogen bonding interactions between the receptor and ligand. The 2D structure of dexamethasone is also depicted in the lower right hand side of the picture for reference.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1M2Z, 1NHZ, 1P93, 3BQD, 3CLD, 3E7C, 3H52, 3K22, 3K23, 4CSJ, 4HN5, 4HN6, 4LSJ, 4MDD, 4P6W, 4P6X
Identifiers
Symbols	NR3C1 ; GCCR; GCR; GCRST; GR; GRL
External IDs	OMIM: 138040 MGI: 95824 HomoloGene: 30960 IUPHAR: 625 ChEMBL: 2034 GeneCards: NR3C1 Gene
Gene ontology Molecular function • RNA polymerase II core promoter proximal region sequence-specific DNA binding • RNA polymerase II core promoter proximal region sequence-specific DNA binding transcription factor activity involved in positive regulation of transcription • sequence-specific DNA binding transcription factor activity • glucocorticoid receptor activity • steroid binding • protein binding • zinc ion binding • glucocorticoid-activated RNA polymerase II transcription factor binding transcription factor activity • protein dimerization activity • steroid hormone binding Cellular component • nucleus • nucleoplasm • cytoplasm • mitochondrial matrix • cytosol • membrane Biological process • regulation of gluconeogenesis • transcription, DNA-templated • regulation of transcription, DNA-templated • transcription from RNA polymerase II promoter • transcription initiation from RNA polymerase II promoter • signal transduction • glucocorticoid metabolic process • gene expression • chromatin modification • adrenal gland development • regulation of glucocorticoid biosynthetic process • maternal behavior • glucocorticoid receptor signaling pathway • glucocorticoid mediated signaling pathway • positive regulation of neuron apoptotic process • positive regulation of transcription from RNA polymerase II promoter • mammary gland duct morphogenesis • cellular response to steroid hormone stimulus • negative regulation of glucocorticoid mediated signaling pathway Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	2908	14815
Ensembl	ENSG00000113580	ENSMUSG00000024431
UniProt	P04150	n/a
RefSeq (mRNA)	NM_000176	NM_008173
RefSeq (protein)	NP_000167	NP_032199
Location (UCSC)	Chr 5: 143.28 – 143.44 Mb	Chr 18: 39.41 – 39.49 Mb
PubMed search	[1]	[2]

The glucocorticoid receptor (GR, or GCR) also known as NR3C1 (nuclear receptor subfamily 3, group C, member 1) is the receptor to which cortisol and other glucocorticoids bind.

The GR is expressed in almost every cell in the body and regulates genes controlling the development, metabolism, and immune response. Because the receptor gene is expressed in several forms, it has many different (pleiotropic) effects in different parts of the body.

When the GR binds to glucocorticoids, its primary mechanism of action is the regulation of gene transcription. The unbound receptor resides in the cytosol of the cell. After the receptor is bound to glucocorticoid, the receptor-glucorticoid complex can take either of two paths. The activated GR complex up-regulates the expression of anti-inflammatory proteins in the nucleus or represses the expression of pro-inflammatory proteins in the cytosol (by preventing the translocation of other transcription factors from the cytosol into the nucleus).

In humans, the GR protein is encoded by NR3C1 gene which is located on chromosome 5 (5q31).

Structure

Like the other steroid receptors, the glucocorticoid receptor is modular in structure and contains the following domains (labeled A - F):

• A/B - N-terminal regulatory domain
• C - DNA-binding domain (DBD)
• D - hinge region
• E - ligand-binding domain (LBD)
• F - C-terminal domain

Ligand binding and response

In the absence of hormone, the glucocorticoid receptor (GR) resides in the cytosol complexed with a variety of proteins including heat shock protein 90 (hsp90), the heat shock protein 70 (hsp70) and the protein FKBP52 (FK506-binding protein 52). The endogenous glucocorticoid hormone cortisol diffuses through the cell membrane into the cytoplasm and binds to the glucocorticoid receptor (GR) resulting in release of the heat shock proteins. The resulting activated form GR has two principle mechanisms of action, transactivation and transrepression, described below.

Transactivation

A direct mechanism of action involves homodimerization of the receptor, translocation via active transport into the nucleus, and binding to specific DNA responsive elements activating gene transcription. This mechanism of action is referred to as transactivation. The biologic response depends on the cell type.

Transrepression

In the absence of activated GR, other transcription factors such as NF-κB or AP-1 themselves are able to transactivate target genes. However activated GR can complex with these other transcription factors and prevent them from binding their target genes and hence repress the expression of genes that are normally upregulated by NF-κB or AP-1. This indirect mechanism of action is referred to as transrepression.

Clinical significance

The GR is abnormal in familial glucocorticoid resistance.

In central nervous system structures, the glucocorticoid receptor is gaining interest as a novel representative of neuroendocrine integration, functioning as a major component of endocrine influence - specifically the stress response - upon the brain. The receptor is now implicated in both short and long-term adaptations seen in response to stressors and may be critical to the understanding of psychological disorders, including some or all subtypes of depression and post-traumatic stress disorder (PTSD). Indeed, long-standing observations such as the mood dysregulations typical of Cushing's disease demonstrate the role of corticosteroids in regulating psychologic state; recent advances have demonstrated interactions with norepinephrine and serotonin at the neural level.

Agonists and antagonists

Dexamethasone and other corticosteroids are agonists, and mifepristone and ketoconazole are antagonists of the GR.

Interactions

Glucocorticoid receptor has been shown to interact with:

• BAG1,
• CEBPB,
• CREBBP,
• DAP3,
• DAXX,
• HSP90AA1,
• HNRPU,
• MED1,
• MED14,
• Mineralocorticoid receptor,
• NRIP1,
• NCOR1,
• NCOA1,
• NCOA2,
• NCOA3,
• POU2F1,
• RANBP9,
• RELA,
• SMAD3,
• SMARCD1,
• SMARCA4
• STAT3,
• STAT5B,
• Thioredoxin,
• TRIM28, and
• YWHAH.

See also

• Membrane glucocorticoid receptor
• Familial/sporadic glucocorticoid resistance (Chrousos Syndrome)
• Selective glucocorticoid receptor agonist (SEGRA)

External links

• Human Protein Reference Database
• Glucocorticoid receptors at the US National Library of Medicine Medical Subject Headings (MeSH)
• FactorBook GR