|
Glucagon Receptor Family
The glucagon receptor family is a group of closely related G-protein coupled receptors which include: * Glucagon receptor * Glucagon-like peptide 1 receptor * Glucagon-like peptide 2 receptor * Gastric inhibitory polypeptide receptor The first three receptors bind closely related peptide hormones (glucagon, glucagon-like peptide-1, glucagon-like peptide-2) derived from the proglucagon polypeptide. The last receptor binds gastric inhibitory polypeptide Glucose-dependent insulinotropic polypeptide (GIP), also known as Gastric inhibitory polypeptide or gastric inhibitory peptide (also abbreviated as GIP), is an inhibiting hormone of the secretin family of hormones. While it is a weak inhibitor .... References External links * {{G protein-coupled receptors G protein-coupled receptors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-protein Coupled Receptor
G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily-related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses. Coupling with G proteins, they are called seven-transmembrane receptors because they pass through the cell membrane seven times. Text was copied from this source, which is available under Attribution 2.5 Generic (CC BY 2.5) license. Ligands can bind either to extracellular N-terminus and loops (e.g. glutamate receptors) or to the binding site within transmembrane helices (Rhodopsin-like family). They are all activated by agonists although a spontaneous auto-activation of an empty receptor can also be observed. G protein-coupled receptors are found only in eukaryotes, including yeast, choanoflagellates, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon Receptor
The glucagon receptor is a 62 kDa protein that is activated by glucagon and is a member of the class B G-protein coupled family of receptors, coupled to G alpha i, Gs and to a lesser extent G alpha q. Stimulation of the receptor results in the activation of adenylate cyclase and phospholipase C and in increased levels of the secondary messengers intracellular cAMP and calcium. In humans, the glucagon receptor is encoded by the gene. Glucagon receptors are mainly expressed in liver and in kidney with lesser amounts found in heart, adipose tissue, spleen, thymus, adrenal glands, pancreas, cerebral cortex, and gastrointestinal tract. Signal transduction pathway A glucagon receptor, upon binding with the signaling molecule glucagon, initiates a signal transduction pathway that begins with the activation of adenylate cyclase, which in turn produces cyclic AMP (cAMP). Protein kinase A, whose activation is dependent on the increased levels of cAMP, is responsible f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon-like Peptide 1 Receptor
The glucagon-like peptide-1 receptor (GLP1R) is a receptor protein found on beta cells of the pancreas and on neurons of the brain. It is involved in the control of blood sugar level by enhancing insulin secretion. In humans it is synthesised by the gene ''GLP1R'', which is present on chromosome 6. It is a member of the glucagon receptor family of G protein-coupled receptors. GLP1R is composed of two domains, one extracellular (ECD) that binds the C-terminal helix of GLP-1, and one transmembrane (TMD) domain that binds the N-terminal region of GLP-1. In the TMD domain there is a fulcrum of polar residues that regulates the biased signaling of the receptor while the transmembrane helical boundaries and extracellular surface are a trigger for biased agonism. Human receptor ligands GLP1R binds glucagon-like peptide-1 (GLP1) and glucagon as its natural endogenous agonists. Receptor agonists: * GLP-1 – endogenous in humans *glucagon – endogenous in humans * Oxyntomodulin * ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon-like Peptide 2 Receptor
Glucagon-like peptide-2 receptor (GLP-2R) is a protein that in human is encoded by the ''GLP2R'' gene located on chromosome 17. Function The GLP2 receptor (GLP2R) is a G protein-coupled receptor superfamily member closely related to the glucagon receptor ( GLP1 receptor). Glucagon-like peptide-2 (GLP2) is a 33-amino acid proglucagon-derived peptide produced by intestinal enteroendocrine cells. Like glucagon-like peptide-1 (GLP1) and glucagon itself, it is derived from the proglucagon peptide encoded by the GCG gene. GLP2 stimulates intestinal growth and upregulates villus height in the small intestine, concomitant with increased crypt cell proliferation and decreased enterocyte apoptosis. Moreover, GLP2 prevents intestinal hypoplasia resulting from total parenteral nutrition. GLP2R, a G protein-coupled receptor superfamily member is expressed in the gut and closely related to the glucagon receptor (GCGR) and the receptor for GLP1 (GLP1R). See also *Glucagon-like peptide-2 Gluca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Inhibitory Polypeptide Receptor
The gastric inhibitory polypeptide receptor (GIP-R), also known as the glucose-dependent insulinotropic polypeptide receptor, is a protein that in humans is encoded by the ''GIPR'' gene. GIP-R is a member of the 7-transmembrane protein family, a class of G protein coupled receptors. GIP-R is found on beta-cells in the pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an end ... where it serves as the receptor for the hormone Gastric inhibitory polypeptide (GIP). Function Gastric inhibitory polypeptide, also called glucose-dependent insulinotropic polypeptide, is a 42-amino acid polypeptide synthesized by K cells of the duodenum and small intestine. It was originally identified as an activity in gut extracts that inhibited gastric acid secretion and gastrin release, but subsequ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon
Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises concentration of glucose and fatty acids in the bloodstream, and is considered to be the main catabolic hormone of the body. It is also used as a medication to treat a number of health conditions. Its effect is opposite to that of insulin, which lowers extracellular glucose. It is produced from proglucagon, encoded by the ''GCG'' gene. The pancreas releases glucagon when the amount of glucose in the bloodstream is too low. Glucagon causes the liver to engage in glycogenolysis: converting stored glycogen into glucose, which is released into the bloodstream. High blood-glucose levels, on the other hand, stimulate the release of insulin. Insulin allows glucose to be taken up and used by insulin-dependent tissues. Thus, glucagon and insulin are part of a feedback system that keeps blood glucose levels stable. Glucagon increases energy expenditure and is elevated under conditions of stress. Glucagon belon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon-like Peptide-1
Glucagon-like peptide-1 (GLP-1) is a 30- or 31-amino-acid-long peptide hormone deriving from the tissue-specific posttranslational processing of the proglucagon peptide. It is produced and secreted by intestinal enteroendocrine L-cells and certain neurons within the nucleus of the solitary tract in the brainstem upon food consumption. The initial product GLP-1 (1–37) is susceptible to amidation and proteolytic cleavage, which gives rise to the two truncated and equipotent biologically active forms, GLP-1 (7–36) amide and GLP-1 (7–37). Active GLP-1 protein secondary structure includes two α-helices from amino acid position 13–20 and 24–35 separated by a linker region. Alongside glucose-dependent insulinotropic peptide (GIP), GLP-1 is an incretin; thus, it has the ability to decrease blood sugar levels in a glucose-dependent manner by enhancing the secretion of insulin. Beside the insulinotropic effects, GLP-1 has been associated with numerous regulatory and protec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucagon-like Peptide-2
Glucagon-like peptide-2 (GLP-2) is a 33 amino acid peptide with the sequence HADGSFSDEMNTILDNLAARDFINWLIQTKITD (see Proteinogenic amino acid) in humans. GLP-2 is created by specific post-translational proteolytic cleavage of proglucagon in a process that also liberates the related glucagon-like peptide-1 (GLP-1). GLP-2 is produced by the intestinal endocrine L cell and by various neurons in the central nervous system. Intestinal GLP-2 is co-secreted along with GLP-1 upon nutrient ingestion. When externally administered, GLP-2 produces a number of effects in humans and rodents, including intestinal growth, enhancement of intestinal function, reduction in bone breakdown and neuroprotection. GLP-2 may act in an endocrine fashion to link intestinal growth and metabolism with nutrient intake. GLP-2 and related analogs may be treatments for short bowel syndrome, Crohn's disease, osteoporosis and as adjuvant therapy during cancer chemotherapy. GLP-2 has an antidepressant effect in a mou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastric Inhibitory Polypeptide
Glucose-dependent insulinotropic polypeptide (GIP), also known as Gastric inhibitory polypeptide or gastric inhibitory peptide (also abbreviated as GIP), is an inhibiting hormone of the secretin family of hormones. While it is a weak inhibitor of gastric acid secretion, its main role is to stimulate insulin secretion. GIP, along with glucagon-like peptide-1 (GLP-1), belongs to a class of molecules referred to as incretins. Synthesis and transport GIP is derived from a 153-amino acid proprotein encoded by the GIP gene and circulates as a biologically active 42-amino acid peptide. It is synthesized by K cells, which are found in the mucosa of the duodenum and the jejunum of the gastrointestinal tract. Like all endocrine hormones, it is transported by blood. Gastric inhibitory polypeptide receptors are seven-transmembrane proteins found on beta-cells in the pancreas. Functions It has traditionally been named ''gastrointestinal inhibitory peptide'' or ''gastric inhibitory pept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
