Melanocortin 3 receptor

Melanocortin 3 receptor (MC3R) is a protein that in humans is encoded by the MC3R gene. It is one of the five known melanocortin receptors, which are members of the G protein-coupled receptor family. MC3R is primarily expressed in the brain, particularly in the hypothalamus, and has been implicated in the regulation of energy homeostasis and body weight.

Structure[edit | edit source]

MC3R is a seven-transmembrane domain G protein-coupled receptor that interacts with melanocortin peptides. The receptor is characterized by a large extracellular N-terminal domain and a short intracellular C-terminal tail. The N-terminal domain is thought to play a role in ligand binding, while the C-terminal tail is involved in receptor activation.

Function[edit | edit source]

MC3R is involved in the regulation of energy homeostasis and body weight. It is activated by melanocortin peptides, including alpha-melanocyte-stimulating hormone (α-MSH) and adrenocorticotropic hormone (ACTH). Activation of MC3R leads to increased cAMP levels and activation of adenylyl cyclase, resulting in increased energy expenditure and decreased food intake.

Clinical significance[edit | edit source]

Mutations in the MC3R gene have been associated with obesity and insulin resistance. Some studies have suggested that these mutations may increase the risk of type 2 diabetes and cardiovascular disease. However, the exact role of MC3R in these conditions is still not fully understood.