Regulation of neuronal cholecystokinin gene transcription

Cholecystokinin (CCK) is a neuroendocrine peptide expressed in I-cells of t he small intestine and in central and peripheral neurons. Whereas intestina l CCK is involved in the release of pancreatic enzymes and the contraction of the gallbladder, cerebral CCK is implicated in a variety of functions, s uch as feeding behaviour, anxiety and memory. The expression of CCK is deve lopmentally regulated. Brain CCK mRNA levels are low before birth, but incr ease markedly shortly after birth and reach adult like patterns of expressi on three weeks after birth during the final maturation of the central nervo us system. In the adult, several substances induce neuronal CCK mRNA expres sion via activation of transcription factors binding to regulatory elements in the CCK promoter. Recent studies have examined the signaling pathways, transcription factors and regulatory elements involved in cAMP, fibroblast growth factor-2, and calcium-induced CCK gene transcription in neuronal cel ls. The review describes the signaling pathways and transcription factors i nvolved in neuronal CCK gene transcription.