CCKAR

CCKAR Full Name

cholecystokinin A receptor

CCKAR Introduction

Cholecystokinin A receptor (CCKAR), also known as CCK1R, is a G protein–coupled receptor (GPCR) that plays a central role in translating gastrointestinal hormone signals into coordinated physiological responses. It is primarily expressed in the pancreas, gallbladder, gastrointestinal tract, and specific regions of the central nervous system, where it binds the peptide hormone cholecystokinin (CCK). For researchers and drug developers, one of the key challenges is understanding how a single receptor can mediate such diverse biological effects—from digestion to satiety—while maintaining signaling specificity. Advances in structural biology, including high-resolution cryo-EM studies, have revealed that CCKAR adopts distinct conformations depending on ligand type (peptide agonists versus small-molecule antagonists), enabling selective coupling to different G proteins. This structural and functional versatility positions CCKAR as a highly tunable pharmacological target, especially in efforts to design biased ligands that can fine-tune downstream signaling pathways without triggering unwanted side effects.

Functionally, CCKAR is best known for its role in activating the canonical Gαq/PLC/IP3-DAG signaling cascade, which leads to intracellular calcium mobilization and protein kinase C (PKC) activation. This signaling axis drives gallbladder contraction, pancreatic enzyme secretion, and modulation of gastric emptying—processes essential for efficient digestion. However, a common pain point in both research and clinical translation is that CCKAR signaling extends far beyond classical digestive functions. Emerging evidence shows that it also contributes to neurogenesis, appetite regulation, and maintenance of mucosal integrity, linking peripheral metabolic control with central nervous system signaling. Importantly, the receptor exhibits "biased signaling," meaning that different ligands can preferentially activate Gq, Gi, or Gs pathways, adding another layer of complexity but also opportunity for therapeutic precision. Understanding these pathway preferences is critical for developing next-generation drugs aimed at metabolic disorders or gastrointestinal dysfunction.

Clinically, dysregulation of CCKAR is strongly associated with several disease states, most notably gallstone disease, where it has been identified as a key genetic determinant (Lith13). Impaired or absent CCKAR function leads to reduced gallbladder motility, bile stasis, and accelerated cholesterol crystal nucleation—hallmarks of gallstone formation. This creates a significant unmet need for targeted therapies that can restore or modulate receptor activity. Beyond gallstones, altered CCKAR expression and signaling have been implicated in obesity, due to its role in satiety signaling, and in certain cancers, where aberrant receptor expression may influence tumor cell proliferation and survival. Additionally, genetic and promoter-level variations affecting CCKAR expression can directly impact feeding behavior and metabolic efficiency, as demonstrated in animal models. Together, these findings highlight CCKAR not only as a key physiological regulator but also as a promising therapeutic target whose precise modulation could address multiple high-burden diseases with improved specificity and efficacy.

Alternate Names for CCKAR

CCKAR; cholecystokinin A receptor; cholecystokinin receptor type A; CCK-AR; CCK-A receptor; cholecystokinin-1 receptor; cholecystokinin type-A receptor; CCK-A; CCKRA; CCK1-R;

• 1.Zeng Q, et al.; Gastrin, Cholecystokinin, Signaling, and Biological Activities in Cellular Processes. Front Endocrinol (Lausanne). 2020, 11:112.
  2.Wang HH, et al.; An Update on the Lithogenic Mechanisms of Cholecystokinin a Receptor (CCKAR), an Important Gallstone Gene for Lith13. Genes (Basel). 2020, 11(12):1438.