Figure 3. Schematic diagram showing the synthesis of ghrelin and obestatin from the same precursor, preproghrelin. Preproghrelin is a 117 amino acid precursor encoded at chromosome 3. Cleavage of this protein leads to the production of ghrelin, a 28 amino acid peptide, and obestatin, a 23 amino acid protein. Ghrelin can be present as both des-acyl- and acyl-ghrelin (figure modified from (291)).