Cholecystokinin Receptor 1 Antibodies

The cholecystokinin type 1 receptor (CCK₁), formerly known as CCK-A and encoded by CCKAR, is a class A G protein-coupled receptor that responds preferentially to sulfated forms of cholecystokinin (CCK). It couples predominantly to Gq/11, activating phospholipase C and increasing intracellular calcium. CCK₁ is expressed in gallbladder smooth muscle, the gastrointestinal tract, and vagal afferent neurons. Dietary fats and proteins stimulate intestinal CCK release, and activation of CCK₁ promotes gallbladder contraction and pancreatic enzyme secretion. CCK₁ signaling in vagal afferents also slows gastric emptying and contributes to meal-induced satiation. Agonist exposure can induce receptor phosphorylation, desensitization, and internalization, limiting responsiveness during sustained stimulation. The synthetic sulfated CCK octapeptide sincalide is approved in the United States for diagnostic use, including stimulation of gallbladder contraction during hepatobiliary imaging. The selective CCK₁ antagonist dexloxiglumide has been evaluated in clinical trials for irritable bowel syndrome. CCK1 receptor desensitization, β-arrestin recruitment and internalization are regulated by phosphorylation of carboxyl-terminal threonine408/threonine409 (pT408/pT409-CCK1), serine412/serine414 (pS412/pS414-CCK1) and serine417/serine419 (pS417/pS419-CCK1). This nomenclature refers to the human CCK1. This phosphorylation motif is conserved across species but corresponds to pT416-CCK1, pS420/pS422-CCK1 and pS425/pS427-CCK1 in mice. For more information on CCK1 pharmacology please refer to the IUPHAR database. For further reading refer to:

Noble F, Wank SA, Crawley JN, Bradwejn J, Seroogy KB, Hamon M, Roques BP. International Union of Pharmacology. XXI. Structure, distribution, and functions of cholecystokinin receptors. Pharmacol Rev. 1999 Dec;51(4):745-81. Erratum in: Pharmacol Rev 2000 Mar;52(1):177. PMID: 10581329.

Dufresne M, Seva C, Fourmy D. Cholecystokinin and gastrin receptors. Physiol Rev. 2006 Jul;86(3):805-47. doi: 10.1152/physrev.00014.2005. PMID: 16816139.