Glucagon is found in the pancreas and is considered a peptide hormone. It plays an integral role in the body and is strongly linked to blood sugar and fatty acids. The main function of this hormone is to increase the concentration of glucose and fatty acids in the bloodstream. For this reason, it is widely seen as the primary catabolic hormone of the body.
Glucagon is produced by proglucagon and is encoded by the GCG gene. It is a 29-amino acid polypeptide and has a molecular mass of 3485 Daltons. As a peptide hormone, this means it is considered a non-steroid. Production of this hormone begins in the pancreatic alpha cells where proglucagon is cleavage by proprotein convertase 2.
Glucagon Mechanism & Function
Glucose binds to the glucagon receptor in the plasma membrane of the cell. This activates G proteins, which interact with the receptor and institute a change that replaces the GDP molecule that was bonded to the alpha subunit.
The main function of glucagon is to increase the concentration of glucose in the bloodstream. It manages this by facilitating the promotion of both gluconeogenesis and glycogenolysis. Glucagon will also decrease fatty acid synthesis in adipose tissue and in the liver. Alongside that, it's shown to boost lipolysis and release fatty acids into the bloodstream. From here, these acids can be used to generate energy for skeletal muscles.
Glucagon primarily interacts with cells and receptors in the pancreas and liver. It will also interact with adipose tissues and fatty acids in the human body.