Glucagon
Glucagon is a pancreatic peptide hormone derived from the proglucagon precursor encoded by the GCG gene, which also gives rise to GLP-1, GLP-2 and a glicentin-like peptide. It opposes the glucose-lowering action of insulin and is a ligand for the glucagon receptor. Browse Assay Genie's current range of Glucagon research reagents below, or read on for the biology behind the target.
The GCG gene encodes pro-glucagon, a precursor that is cleaved into four distinct mature peptides. Glucagon itself is a pancreatic hormone that counteracts the glucose-lowering action of insulin by stimulating glycogenolysis and gluconeogenesis in the liver. During prolonged fasting or stress it also promotes lipolysis and ketone body formation. Its secretion is stimulated by low blood glucose and inhibited by high glucose or insulin. Glucagon binds a specific G-protein linked receptor, the glucagon receptor, which activates the Gs protein-adenylate cyclase-cAMP-protein kinase A pathway to regulate carbohydrate and lipid metabolism.
The other products of proglucagon are produced by intestinal L-cells and secreted in response to nutrient ingestion. Glucagon-like peptide-1 (GLP-1) enhances glucose-dependent insulin secretion, suppresses glucagon release, slows gastric emptying and promotes satiety, which makes it a key incretin hormone for maintaining postprandial glucose levels. Glucagon-like peptide-2 (GLP-2) acts mainly on the gut, promoting intestinal growth, enhancing nutrient absorption and supporting mucosal integrity. Each signals through its own G-protein-coupled receptor, GLP-1 receptor and GLP-2 receptor respectively. The fourth peptide resembles glicentin, an enteroglucagon made in L-cells, and is thought to influence intestinal growth, gut motility and the secretion of other gut hormones.
Pro-glucagon is a secreted protein that belongs to the glucagon family, and HGNC classes the gene among receptor ligands. UniProt notes that it may modulate gastric acid secretion and gastro-pyloro-duodenal activity, and may contribute to intestinal mucosal growth early in life. Analogues of GLP-1 are used clinically to treat type 2 diabetes and obesity. Mouse and rat both carry a Gcg ortholog.
Glucagon opposes insulin by stimulating hepatic glycogenolysis and gluconeogenesis, and its release is governed by blood glucose and insulin levels.
GLP-1 enhances glucose-dependent insulin secretion and suppresses glucagon, and its analogues are used clinically for type 2 diabetes and obesity.
Glucagon promotes lipolysis and ketone body formation during prolonged fasting or stress, acting through the glucagon receptor and cAMP-PKA signalling.
GLP-2 and glicentin-like peptides support intestinal growth, nutrient absorption, mucosal integrity and gut motility.
Glucagon is a pancreatic hormone that counteracts insulin by stimulating glycogenolysis and gluconeogenesis in the liver. It also promotes lipolysis and ketone body formation during prolonged fasting or stress. It signals through the glucagon receptor, activating Gs, adenylate cyclase, cAMP and protein kinase A.
The GCG gene encodes a proglucagon precursor that is cleaved into four peptides: glucagon, glucagon-like peptide-1, glucagon-like peptide-2 and a glicentin-like peptide. Aliases such as GLP1, GLP2 and GRPP reflect these products. Tissue-specific processing yields pancreatic glucagon or intestinal L-cell peptides.
Mouse and rat each have a Gcg ortholog of the human GCG gene, so glucagon biology can be studied in rodent models. Check the datasheet of any product for its validated reactivity.
Other proglucagon-derived peptides, their receptors and insulin, which together regulate glucose metabolism and gut physiology.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P01275; product specifications from Assay Genie datasheets.