ACTH receptor

The adrenocorticotropic hormone receptor or ACTH receptor also known as the melanocortin receptor 2 or MC2 receptor is a type of is_associated_with::melanocortin receptor (type 2) which is specific for is_associated_with::ACTH.

Structure
Both human and bovine ACTH receptors are synthesized as 297 residue long proteins. There is 81% homology between human and bovine sequences. The full length sequence includes seven hydrophobic domains that are predicted as transmembrane segments. In the third intracellular loop of the receptor a protein kinase A and protein kinase c phosphorylation motifs have been detected.

Tissue and subcellular localization
ACTH receptor is found in the is_associated_with::zona fasciculata of the human is_associated_with::adrenal cortex. Binding of the receptor by ACTH stimulates the production of is_associated_with::cortisol. (By contrast, is_associated_with::aldosterone production from the is_associated_with::zona glomerulosa is stimulated primarily by is_associated_with::angiotensin II.)

Protein recognition at the receptor uses energy obtained from the dephosphorylation of ATP to cAMP by adenylate cyclase. ACTH receptors are located on the plasma membrane, and are is_associated_with::G protein-coupled receptors.

The ACTH receptor uses cAMP as a secondary messenger.

Pathology
Mutations in this receptor cause is_associated_with::familial glucocorticoid deficiency type 1, in which patients have high levels of serum ACTH and low levels of cortisol.