Glucagon receptor
Category: Receptors · Last updated
The Glucagon receptor (GCGR) is a class-B Gαs-coupled G-protein-coupled receptor. Its endogenous ligand is glucagon, the 29-residue peptide hormone produced by pancreatic α-cells. GCGR is most highly expressed on hepatocytes but is also present on adipose, renal, cardiac, and central-nervous-system tissues.
Signaling
GCGR activation drives adenylate cyclase → cAMP → PKA. In hepatocytes:
- Glycogenolysis (breakdown of stored glycogen → glucose-6-phosphate)
- Gluconeogenesis (de novo glucose synthesis from amino acids and lactate)
- Increased basal metabolic rate via direct effects on hepatic energy turnover
GCGR is a counter-regulatory hormone receptor relative to insulin; net plasma glucose rises following GCGR activation.
Relevance to research peptides
- Retatrutide · triple GLP-1R / GIPR / GCGR agonist. The GCGR component is the key pharmacological differentiator from Tirzepatide.