Agouti-related peptide (AgRP) is a neuropeptide produced in the brain in the arcuate nucleus of the hypothalamus. It is an endogenous antagonist of melanocortin receptors (MC3-R and MC4-R) which plays a critical role in energy balance.
It was identified independently by two teams based on sequence similarity with Agouti signalling peptide, a protein synthesized in the skin that controls coat color1,2. 
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