CCKAR

CCKAR, short for cholecystokinin A receptor, is a human gene that encodes a member of the G protein-coupled receptor (GPCR) family. The receptor is also known as the CCK1 receptor (CCK1R) and is one of two main receptors for the peptide hormone cholecystokinin (CCK), the other being CCKBR (CCK2 receptor). CCKAR is a class A GPCR that, upon binding CCK, primarily couples to Gq/11 proteins to activate phospholipase C, leading to inositol trisphosphate (IP3) production, calcium mobilization, and protein kinase C activation.

Expression of CCKAR is strongest in peripheral tissues involved in digestion, particularly pancreatic acinar cells and gallbladder smooth muscle, where it mediates digestive and biliary responses. It is also present in certain neurons, contributing to neuromodulatory effects. Through these tissues, CCKAR participates in physiological processes such as pancreatic enzyme secretion, gallbladder contraction, and regulation of gastric motility and satiety.

Physiological and potential clinical roles of CCKAR include modulation of appetite and digestion, as well as involvement in neurobehavioral processes linked to anxiety and pain in some contexts. Genetic variation in CCKAR has been investigated for associations with obesity and appetite regulation, while pharmacological modulation of CCKAR has been explored in preclinical and clinical settings for obesity and various gastrointestinal conditions. Overall, CCKAR functions as a key mediator of CCK signaling in the digestive system and contributes to broader gut–brain interactions.