The gastric inhibitory polypeptide receptor (GIP-R) also known as the glucose-dependent insulinotropic polypeptide receptor is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the GIPR gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. The GIP-R is seven-transmembrane proteins found on beta-cells in the pancreas

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

.

Function

Gastric inhibitory polypeptide (GIP), 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.