Proglucagon Explained

Proglucagon is a protein that is cleaved from preproglucagon. Preproglucagon in humans is encoded by the GCG gene.^{[1] [2]}

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.^[3]

Further reading

• Drucker DJ . Biologic actions and therapeutic potential of the proglucagon-derived peptides . Nature Clinical Practice. Endocrinology & Metabolism . 1 . 1 . 22–31 . November 2005 . 16929363 . 10.1038/ncpendmet0017 . 18101345 .

External links

• Web site: Molecular and Cellular Mechanisms of Glucagon Synthesis and Secretion . Dhanvantari S . https://web.archive.org/web/20070929165337/http://www.lawsonimaging.ca/investigators/sdhanvan/research2.htm . 29 September 2007 . lawsonimaging.ca .
• Web site: PC1 Cleavage Sites . https://web.archive.org/web/20051228091634/http://www.phoenixpeptide.com/Catalog%20Files/GLP-1/ee0929017001.gif . 28 December 2005 . phoenixpeptide.com .
• Web site: GLP-1 is Derived From Proglucagon . medscape.com .
• Web site: Pro-glucagon . PDBe-KB Aggregated Views of Proteins . EMBL-EBI . Wellcome Genome Campus, Hinxton, Cambridgeshire .

Notes and References

1. Schroeder WT, Lopez LC, Harper ME, Saunders GF . Localization of the human glucagon gene (GCG) to chromosome segment 2q36–37 . Cytogenetics and Cell Genetics . 38 . 1 . 76–79 . 1984 . 6546710 . 10.1159/000132034 .
2. White JW, Saunders GF . Structure of the human glucagon gene . Nucleic Acids Research . 14 . 12 . 4719–4730 . June 1986 . 3725587 . 311486 . 10.1093/nar/14.12.4719 .
3. Pollock HG, Hamilton JW, Rouse JB, Ebner KE, Rawitch AB . Isolation of peptide hormones from the pancreas of the bullfrog (Rana catesbeiana). Amino acid sequences of pancreatic polypeptide, oxyntomodulin, and two glucagon-like peptides . The Journal of Biological Chemistry . 263 . 20 . 9746–9751 . July 1988 . 3260236 . 10.1016/S0021-9258(19)81581-8 . free .