Melanocortin receptor

Melanocortin receptors are members of the rhodopsin family of 7-transmembrane G protein-coupled receptors.

There are five known members of the melanocortin receptor system each with differing specificities for melanocortins:

• MC1R. MC1R is associated with pigmentation genetics.
• MC2R. MC2R is also known as the ACTH receptor or corticotropin receptor because it is specific for ACTH alone.
• MC3R. MC3R is associated with childhood growth, accrual of lean mass and onset of puberty.
• MC4R. Defects in MC4R are a cause of autosomal dominant obesity, accounting for 6% of all cases of early-onset obesity.
• MC5R. MC5R

These receptors are inhibited by endogenous inverse agonists agouti signalling peptide and agouti-related peptide, and activated by synthetic (i.e. afamelanotide) and endogenous agonist melanocyte-stimulating hormones.