Proglucagon
Proglucagon is a protein that is a precursor of glucagon and several other components. It is cleaved from preproglucagon.
Proglucagon is generated in the alpha cells of the pancreas and in the intestinal L cells in the distal ileum and colon.
Preproglucagon in humans is encoded by the GCG gene and is composed of 180 amino-acid residues.
More specifically, preproglucagon is cleaved into the following components in different organs:
- Signal peptide - removed from preproglucagon to form proglucagon
- Glicentin
- Glicentin-related pancreatic polypeptide
- Oxyntomodulin
- Glucagon
- Glucagon-like peptide 1 - first seven residues further cleaved
- Glucagon-like peptide 2