Receptors
The five receptors
MC1R through MC5R — five G-protein-coupled receptors that read the melanocortin signal in different tissues.
The melanocortin peptides act through five receptors, each with its own tissue distribution, ligand preferences, and physiology. Each now has a full reference page — select one below, or trace which ligands hit which receptor in the interactive explorer.
Switches melanocytes from red/yellow pheomelanin toward brown/black eumelanin — the master control of pigmentation and UV response.
The ACTH receptor — drives adrenal steroidogenesis and cortisol output at the bottom of the HPA stress axis.
Tunes energy partitioning, the timing of puberty and growth, and natriuresis; a brake complementing MC4R.
The central rheostat of appetite and body weight — and the target of the anti-obesity agent setmelanotide.
Regulates exocrine secretion — notably sebum and lipid production — and contributes to immune modulation.