Peptidomic Analysis of the Central Nervous System of the Protochordate, Ciona intestinalis: Homologs and Prototypes of Vertebrate Peptides and Novel Peptides
Peptidomic Analysis of the Central Nervous System of the Protochordate, Ciona intestinalis: Homologs and Prototypes of Vertebrate Peptides and Novel Peptides
复制标题
DOI：
10.1210/en.2010-1348
复制
发表时间：
2011-06-01
期刊：
影响因子：
4.8
通讯作者：
Satake, Honoo
中科院分区：
文献类型：
--
作者：
Kawada, Tsuyoshi;Ogasawara, Michio;Satake, Honoo
海鞘作为最接近脊椎动物的脊索类无脊椎动物的系统发育位置表明，它们可能具有脊椎动物肽激素和神经肽的同源物和/或原型，以及海鞘特异性肽。然而，到目前为止，在海鞘中只鉴定出少数肽。在本研究中，我们鉴定了海鞘中多种多肽。基于质谱的肽组学分析检测到33个多肽，其中包括26个新多肽。海鞘肽主要分为三类：1)脊椎动物肽的原型和同源物，如从未在任何无脊椎动物中发现的丙氨酸/丙氨酸样肽；2)与脊椎动物多肽部分同源的肽，包括新型神经鞘样肽；3)新多肽。这些结果不仅证明了C. ninteinalis具有多种脊椎动物神经肽和肽激素的同源物和原型，而且表明其中一些肽可能在海鞘特异性进化谱系中分化。所有的Ciona肽基因都在神经复合体中表达，而一些肽基因转录本也分布在包括卵巢在内的外周组织中。此外，一种名为C. ninteinalis的神经紧张素样肽6 （neurotensin样peptide 6）可下调琼脂娜卵黄源性卵母细胞的生长。这些结果表明，Ciona肽不仅在神经组织中作为神经肽，而且在非神经组织中作为激素，并且与其他无脊椎动物（如线虫、昆虫和海胆）不同，海鞘建立了具有特定分子多样性的神经肽能神经内分泌、内分泌和神经系统的进化起源。（内分泌学152:2416-2427,2011）
The phylogenetic position of ascidians as the chordate invertebrates closest to vertebrates suggests that they might possess homologs and/or prototypes of vertebrate peptide hormones and neuropeptides as well as ascidian-specific peptides. However, only a small number of peptides have so far been identified in ascidians. In the present study, we have identified various peptides in the ascidian, Ciona intestinalis. Mass spectrometry-based peptidomic analysis detected 33 peptides, including 26 novel peptides, from C. intestinalis. The ascidian peptides are largely classified into three categories: 1) prototypes and homologs of vertebrate peptides, such as galanin/galanin-like peptide, which have never been identified in any invertebrates; 2) peptides partially homologous with vertebrate peptides, including novel neurotesin-like peptides; 3) novel peptides. These results not only provide evidence that C. intestinalis possesses various homologs and prototypes of vertebrate neuropeptides and peptide hormones but also suggest that several of these peptides might have diverged in the ascidian-specific evolutionary lineage. All Ciona peptide genes were expressed in the neural complex, whereas several peptide gene transcripts were also distributed in peripheral tissues, including the ovary. Furthermore, a Ciona neurotensin-like peptide, C. intestinalis neurotensin-like peptide 6, was shown to down-regulate growth of Ciona vitellogenic oocytes. These results suggest that the Ciona peptides act not only as neuropeptides in the neural tissue but also as hormones in nonneuronal tissues and that ascidians, unlike other invertebrates, such as nematodes, insects, and sea urchins, established an evolutionary origin of the peptidergic neuroendocrine, endocrine, and nervous systems of vertebrates with certain specific molecular diversity. (Endocrinology 152: 2416-2427, 2011)