Study of calcitonin (CT) family in an amphioxus, Branchiostoma floridae : Coevolution among CT peptide, CT receptor, and receptor activity- modifying protein.

降钙素(CT)家族在脊椎动物中表现出高分子和功能的多样性。为了阐明CT家族的起源，从文昌鱼(Branchiostoma Floridae)中鉴定了CT肽、CT受体(CTR)和受体活性修饰蛋白(RAMP)。此外，对CTR和RAMP在哺乳动物细胞中表达的分析表明，CTR和RAMP的共表达是CT多肽的配体活性所必需的，而RAMP是CTR细胞表面转位所必需的。这些结果表明，文昌鱼和脊椎动物的共同祖先中已经存在CT肽、CTR和RAMP。

Calcitonin (CT) family shows high molecular and functional diversification in vertebrates. To elucidate the origin of CT family, CT peptide, CT receptor (CTR), and receptor activity-modifying protein (RAMP) were identified from an amphioxus, Branchiostoma floridae, which is close animal of vertebrates. Furthermore, analysis ofCTR and RAMP expressed in mammalian cell line demonstrated that co-expression of CTR and RAMP is required for ligand activity of CT peptide, and that RAMP is necessary for cell-surface translocation of CTR. These results let us conclusion that CT peptide, CTR, and RAMP have already existed in the common ancestor between vertebrates and amphioxus.