Cholecystokinin type A receptor (CCK1R)

The **Cholecystokinin type A receptor (CCK1R)** is a G protein-coupled receptor predominantly expressed in the gastrointestinal system (gallbladder, pancreas, GI tract) and in discrete regions of the central and peripheral nervous system[2][4][5]. It selectively binds sulfated forms of the hormone cholecystokinin (CCK), activating downstream Gq protein signaling pathways. This results in increased intracellular calcium, leading to stimulation of pancreatic enzyme secretion, gallbladder contraction, and inhibition of gastric emptying. In the brain, CCK1R mediates satiety, modulates feeding behavior, and interacts with dopaminergic neurotransmission. Dysregulation or altered sensitivity of CCK1R is implicated in obesity, gastrointestinal motility disorders, and possibly in certain neuropsychiatric conditions. The receptor features seven transmembrane domains typical of Family A GPCRs and exhibits significant selectivity in ligand recognition and activation, differentiating it from CCK2R (Cholecystokinin type B receptor)[2][3][4][5][6].

Other names

Cholecystokinin A receptorCCK1 receptorCCKARCCK-A receptor

Agonists (e.g., cholecystokinin) bind to the receptor, activating Gq-mediated signaling, stimulating phospholipase C, increasing intracellular calcium, and leading to physiological effects such as enzyme secretion and muscle contraction[5]. Antagonists inhibit this pathway, blocking satiety signals, gallbladder contraction, and pancreatic secretion, and have been explored for indications from appetite suppression to gastrointestinal disorders[2][4][5].