Molecular cloning and expression of cDNA encoding brain preprocholecystokinin in goldfish.

A cholecystokinin (CCK) precursor cDNA of 782 bp was identified from goldfish brain. The open reading frame (369 bp) encodes the 123 amino acid precursor which contains mono- and di-basic amino acid endoproteolytic cleavage, C-terminal alpha-amidation and tyrosyl sulfation sites. Expression studies revealed the presence of preproCCK mRNA in the gastrointestinal tract, pituitary and a wide range of brain areas from the olfactory bulbs to the posterior brain region. We have also confirmed the presence of CCK mRNA in the posterior ventrolateral hypothalamus by in situ hybridization, supporting a role of CCK in feeding behavior and regulation of pituitary hormone secretion.