Glucagon receptors

Abstract

Glucagon is a pancreatic peptide hormone that, as a counterregulatory hormone for insulin, stimulates glucose release by the liver and maintains glucose homeostasis. First described as a glucagon binding entity functionally linked to adenylyl cyclase, the glucagon receptor is a member of the family B receptors within the G protein coupled superfamily of seven transmembrane-spanning receptors. During the past decade, considerable progress has been made in the identification of the molecular determinants of the glucagon receptor that are important for ligand binding and signal transduction, in the development of glucagon analogs and of nonpeptide small molecules acting as receptor antagonists, and in the characterization of the mechanisms involved in the regulation of expression of the glucagon receptor gene. In the present review, the current knowledge of glucagon receptor structure, function and expression is described, with emphasis on the metabolic fate of glucagon and on the endocytosis and cell itinerary of both ligand and receptor.

The Involvement of Cholesterol in Sepsis and Tolerance to Lipopolysaccharide Highlighted by the Transcriptome Analysis of Zebrafish (Danio rerio)

“…This is consistent with reports in mammals because insulin regulates the inflammatory response either directly or indirectly. [65][66][67][68][69][70][71][72] As in the case of the lethal LPS treatment, the lipid metabolism-related genes were affected: the low-density lipoprotein receptor (LDLR) was the most up-modulated gene at 4 dpf. Because LPS can be bound by triglyceride-rich lipoproteins (TRL) that may be internalized through the LDLR pathway, the internalization of lipoprotein bound endotoxin (TRL-LPS) could attenuate the systemic inflammatory response.…”

Identification of plasma protease derived metabolites of glucagon and their formation under typical laboratory sample handling conditions

“…6 minutes in diabetic subjects [2] . The liver and kidney are primarily responsible for glucagon metabolism in vivo, although some metabolism also occurs in the blood compartment, and a wide range of metabolites have been identified [3] .…”

“…For example, glucagon , glucagon , and glucagon [1][2][3][4][5][6][7][8][9][10][11][12][13] are formed by hepatocytes in the liver [4] [5] . Glucagon [1][2][3][4][5][6][7][8][9][10][11][12][13] and glucagon [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] , and the minor metabolites glucagon [1][2][3][4][5][6][7][8]…”

“…Glucagon [1][2][3][4][5][6][7][8][9][10][11][12][13] and glucagon [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] , and the minor metabolites glucagon [1][2][3][4][5][6][7][8][9][10] , glucagon [14][15][16][17][18][19][20][21][22][23][24][25] and glucagon [23][24]…”

“…For example, although the C-terminal region of glucagon improves receptor binding, peptides lacking this region, such as glucagon and glucagon [1][2][3][4][5][6] , are essentially fully active glucagon derivatives, but with lower potency [12] . In contrast, modifications at the amino-terminus of glucagon, including removal of the His residue, have a greater effect on receptor binding affinity and biological activity [13] .…”