Melanocortin receptor (mainly Melanocortin 4 receptor for appetite, Melanocortin 1 receptor for pigmentation, with MC3R and MC5R also involved) (MC1R, MC3R, MC4R, MC5R)

α-Melanocyte-stimulating hormone (α-MSH) is a peptide hormone derived from proopiomelanocortin (POMC) that acts as a potent ligand for melanocortin receptors (MC1R–MC5R). α-MSH signaling through these receptors regulates a wide range of biological functions, including appetite suppression and energy expenditure (especially via MC4R in the hypothalamus), pigmentation and photoprotection (via MC1R in melanocytes), antioxidant defense and DNA repair (by activation of p53 and DNA repair enzymes), immune system modulation (by inhibiting inflammatory signaling and promoting regulatory T cell differentiation), and cardiac hypertrophy (through MC5R in heart tissues)[1][2][3][4][5]. Melanocortin receptor signaling is under investigation as a therapeutic target in obesity, metabolic disorders, pigmentary diseases, inflammatory and autoimmune diseases, melanoma, and cardiovascular health. Synthetic analogs and receptor-selective agonists/antagonists are used in research and therapy to modulate these pathways.

Other names

Alpha-melanocyte-stimulating hormone pathwaymelanocortin signaling pathwaymelanocortin receptor signalingcentral melanocortin system

Agonism at melanocortin receptors (MC1R, MC3R, MC4R, MC5R) cAMP/PKA-mediated signal transduction Modulation of p53 phosphorylation and DNA repair enzyme expression Suppression of pro-inflammatory signaling via NF-kB inhibition Induction of Treg cell differentiation from effector T cells