Identification of a receptor for annetocin,invertebrate oxytocin/vasopressin superfamily peptide

摘要

Oxytocin(OT)and vasopressin(VP)are homologous mammalian neurohypophysial peptide hormones(Table 1).Both families are widely distributed in various vertebrate species.The OT family and VP family peptides are classified by the amino acid residue of position 8:VP family peptides contain a basic amino acid,and OT family peptides contain neutral one.OT family participates in uterotonic and milk-ejection processes of the reproductive behavior of mammals,whereas VP is responsible for the control of osmotic balance.In invertebrates,OT/VP-related peptides have also been isolated from several species.An annelid structurally OT-related peptide,annetocin(Table 1),was identified in the earthworm Eisenia foetida.The peptide sequence and precursor organization of annetocin are highly similar to those of OT and VP,revealing that the OT/VP superfamily peptides are evolutionarily conserved in annelida.Moreover,injection of annetocin into earthworms induces egg-laying behavior that is responsible for reproduction.