Cholecystokinin b receptor

Cholecystokinin B receptor
PDB rendering based on 1l4t.
Available structures
PDB Ortholog search: RCSB
Identifiers
CCKBR Gene
RNA expression pattern

The cholecystokinin B receptor also known as CCKBR or CCK2 is a protein[1] that in humans is encoded by the CCKBR gene.[2]

This gene encodes a G protein-coupled receptor for gastrin and cholecystokinin (CCK),[3][4][5] regulatory peptides of the brain and gastrointestinal tract. This protein is a type B gastrin receptor, which has a high affinity for both sulfated and nonsulfated CCK analogs and is found principally in the central nervous system and the gastrointestinal tract. A misspliced transcript variant including an intron has been observed in cells from colorectal and pancreatic tumors.[6]

CNS effects

CCK receptors significantly influence neurotransmission in the brain, regulating anxiety, feeding, and locomotion. CCK-B expression may correlate parallel to anxiety and depression phenotypes in humans. CCK-B receptors possess a complex regulation of dopamine activity in the brain. CCK-B activation appears to possess a general inhibitory action on dopamine activity in the brain, opposing the dopamine-enhancing effects of CCK-A. However, the effects of CCK-B on dopamine activity vary depending on location.[7] CCK-B antagonism enhances dopamine release in rat striatum.[8] Activation enhances GABA release in rat anterior nucleus accumbens.[9] CCK-B receptors modulate dopamine release, and influence the development of tolerance to opioids.[10] CCK-B activation decreases amphetamine-induced DA release, and contributes to individual variability in response to amphetamine.[11]

In rats, CCK-B antagonism prevents the stress-induced reactivation of cocaine-induced conditioned place preference, and prevents the long-term maintenance and reinstatement of morphine-induced CPP.[12] Blockade of CCK-B potentiates cocaine-induced dopamine overflow in rat striatum.[8] CCK-B may pose a modulatory role in parkinson's disease. Blockade of CCK-B in dopamine-depleted squirrel monkeys induces significant enhancement of locomotor response to L-DOPA.[13]

Gastrointestinal Tract

The cholecystokinin B receptor is stimulated by CCK and gastrin in the stomach during digestion.

Selective Ligands

The cholecystokinin B receptor responds to a number of ligands.

Agonists

Antagonists

  • Proglumide
  • CI-988
  • CI-1015
  • L-365,260
  • L-369,293
  • YF-476
  • YM-022
  • RP-69758
  • LY-225,910
  • LY-288,513
  • PD-135,158
  • PD-145,942

Inverse agonists

  • L-740,093

See also

References

Further reading

This article incorporates text from the United States National Library of Medicine, which is in the public domain.