Elasmobranchs express separate cholecystokinin and gastrin genes

AUTOR(ES)

Johnsen, Anders H.

FONTE

The National Academy of Sciences of the USA

RESUMO

The peptide hormone gastrin was long believed to be specific for higher vertebrates, whereas its homologue, cholecystokinin (CCK), has been assumed to represent the original ancestor of the CCK/gastrin family. To trace the divergence of the CCK/gastrin family beyond birds, reptiles, and amphibians we have now examined sharks. Distinct CCK and gastrin peptides were identified in two shark species, the spiny dogfish (Squalus acanthias) and the porbeagle (Lamna cornubica). The corresponding genes and cDNAs were isolated and sequenced from the spiny dogfish. Comparison with several vertebrate species show that the CCK gene and peptide structures have been considerably more conserved than the corresponding gastrin structures. Alignment of the dogfish prepropeptides displays similarities that support the hypothesis that they share a common ancestor. Our findings move the CCK/gastrin family segregation back to at least 350 million years ago. This event must have occurred before, or perhaps during, the evolution of cartilagenous fishes, probably concomitant with the occurrence of gastric acid secretion.

Documentos Relacionados

• Gastrin and cholecystokinin in pituitary neurons.
• Antiproliferative gastrin/cholecystokinin receptor antagonists target the 78-kDa gastrin-binding protein.
• Inter- and intraspecies polymorphisms in the cholecystokinin-B/gastrin receptor alter drug efficacy
• Cholecystokinin-B/gastrin receptors enhance wound healing in the rat gastric mucosa
• Immunohistochemical localization of cholecystokinin- and gastrin-like peptides in the brain and hypophysis of the rat