Characterization of a novel vasopressin/oxytocin superfamily peptide and its receptor from an ascidian, Ciona intestinalis
Characterization of a novel vasopressin/oxytocin superfamily peptide and its receptor from an ascidian, Ciona intestinalis
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DOI：
10.1016/j.peptides.2008.05.030
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发表时间：
2008-10-01
期刊：
影响因子：
3
通讯作者：
Satake, Honoo
中科院分区：
文献类型：
--
作者：
Kawada, Tsuyoshi;Sekiguchi, Toshio;Satake, Honoo
血管加压素（VP）/催产素（OT）超家族肽是分布最广泛的神经肽和/或神经垂体激素之一，但尚未在任何后口无脊椎动物（包括原脊索动物、海鞘）中得到表征。在本研究中，我们显示了一个新的VP/OT超家族肽及其受体的海鞘，玻璃海鞘的鉴定。有趣的是，玻璃海鞘VP/OT相关肽（Ci-VP）与其他9个氨基酸和C-末端酰胺化的VP/OT超家族肽不同，由13个氨基酸组成，并且缺乏C-末端酰胺化。质谱法证实了神经复合物中存在13个残基的Ci-VP。此外，与其他VP/OT对应物相比，14个半胱氨酸中的10个在neurophysin结构域中是保守的。这些结果表明，VP/OT超家族在海鞘中是保守的，但Ci-VP基因编码一个前所未有的VP/OT相关肽和neurophysin蛋白。Ci-VP还显示在生理浓度下激活其内源性受体Ci-VP-R，证实Ci-VP作为内源性配体的功能性。Ci-VP基因仅在脑神经元中表达，而Ci-TK-R mRNA分布在各种组织中，包括神经复合体、消化道、性腺和心脏。这些表达谱表明，Ci-VP，像其他VP/OT超家族肽，作为一个多功能的神经肽。总之，我们的数据揭示了VP/OT超家族在原脊索动物中的进化保守性和特异性分歧。这是VP/OT超家族肽及其同源受体不仅来自海鞘，而且来自后口无脊椎动物的第一个分子表征。(C)2008年爱思唯尔公司All rights reserved.
The vasopressin (VP)/oxytocin (OT) superfamily peptides are one of the most widely distributed neuropeptides and/or neurohypophysial hormones, but have ever not been characterized from any deuterostome invertebrates including protochordates, ascidians. In the present study, we show the identification of a novel VP/OT superfamily peptide and its receptor in the ascidian, Ciona intestinalis. intriguingly, the Ciona VP/OT-related peptide (Ci-VP), unlike other 9-amino acid and C-terminally amidated VP/OT superfamily peptides, consists of 13 amino acids and lacks a C-terminal amidation. Mass spectrometry confirmed the presence of the 13-residue Ci-VP in the neural complex. Furthermore, 10 of 14 cysteines are conserved in the neurophysin domain, compared with other VP/OT counterparts. These results revealed that the VP/OT superfamily is conserved in ascidians, but the Ci-VP gene encodes an unprecedented VP/OT-related peptide and neurophysin protein. Ci-VP was also shown to activate its endogenous receptor, Ci-VP-R, at physiological concentrations, confirming the functionality of Ci-VP as an endogenous ligand. The Ci-VP gene was expressed exclusively in neurons of the brain, whereas the Ci-TK-R mRNA was distributed in various tissues including the neural complex, alimentary tract, gonad, and heart. These expression profiles suggest that Ci-VP, like other VP/OT superfamily peptides, serves as a multifunctional neuropeptides. Altogether, our data revealed both evolutionary conservation and specific divergence of the VP/OT superfamily in protochordates. This is the first molecular characterization of a VP/OT superfamily peptide and its cognate receptor from not only ascidians but also deuterostome invertebrates. (C) 2008 Elsevier Inc. All rights reserved.