The gastric inhibitory polypeptide receptor (GIP-R), also known as the glucose-dependent insulinotropic polypeptide receptor, is a
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respon ...
that in humans is encoded by the ''GIPR''
gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...
.
GIP-R is a member of the 7-transmembrane protein family, a class of
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 p ...
s.
GIP-R is found on
beta-cells
Beta cells (β-cells) are a type of cell found in pancreatic islets that synthesize and secrete insulin and amylin. Beta cells make up 50–70% of the cells in human islets. In patients with Type 1 diabetes, beta-cell mass and function are dimi ...
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 en ...
where it serves as the receptor for the hormone
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 ...
(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 subsequently was demonstrated to stimulate insulin release potently in the presence of elevated glucose. The insulinotropic effect on pancreatic islet beta-cells was then recognized to be the principal physiologic action of GIP. Together with glucagon-like peptide-1, GIP is largely responsible for the secretion of insulin after eating. It is involved in several other facets of the anabolic response.
References
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{{NLM content
G protein-coupled receptors