Proglucagon is a protein that is cleaved from preproglucagon. Preproglucagon in humans is encoded by the GCG gene. Proglucagon is a precursor of glucagon, and several other components. It is generated in the alpha cells of the pancreas and in the intestinal L cells in the distal ileum and colon. It is also cleaved into the following components in different organs: Signal peptide (1-20) – removed from preproglucagon to form proglucagon Glicentin (21–89) Glicentin-related pancreatic polypeptide (GRPP, 21-50) Oxyntomodulin (OXY or OXM, 53–89) Glucagon (53–81) Glucagon-like peptide 1 (GLP-1, 92–128) – first seven residues further cleaved Glucagon-like peptide 2 (GLP-2, 146–178) Proglucagon itself is a protein with three repeats of slightly different secretin family hormones to be cleaved to form mature hormones. References Further reading External links Pancreatic hormones Precursor proteins