Optimized deep-targeted proteotranscriptomic profiling reveals unexplored Conus toxin diversity and novel cysteine frameworks
Optimized deep-targeted proteotranscriptomic profiling reveals unexplored Conus toxin diversity and novel cysteine frameworks
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DOI：
10.1073/pnas.1501334112
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发表时间：
2015-07-21
影响因子：
11.1
通讯作者：
Alewood, Paul F.
中科院分区：
文献类型：
--
作者：
Lavergne, Vincent;Harliwong, Ivon;Alewood, Paul F.
锥螺是捕食性海洋腹足类动物，其特征在于复杂的毒液装置负责合成和递送富含半胱氨酸的毒素肽的复杂混合物。这些芋螺毒素折叠成小的高度结构化的框架，使它们能够有效地和选择性地与异源离子通道和受体相互作用。迄今为止，已在芋螺属中鉴定了来自估计数量> 70，000种生物活性肽的约2，000种毒素。在这里，我们描述了一个高分辨率的审讯的转录组（可在www.ddbj.nig.ac.jp）和蛋白质组的不同舱室的芋螺毒液装置。使用生物化学和生物信息学工具，我们发现了迄今为止在单个芋螺标本中发现的最高数量的芋螺肽，其中3，305个新的前体毒素序列被分类为9个已知的超家族（A，I1，I2，M，O 1，O2，S，T，Z），并鉴定了16个新的超家族，显示出独特的信号肽特征。我们还能够描述含有具有生物活性的C-C-CC-C-C抑制剂胱氨酸结和CC-C-C基序（分别为168和44种毒素）的毒液肽的最大群体，以及显示来自已知芋螺毒素基序的奇数个半胱氨酸残基的208种新芋螺毒素。重要的是，揭示了六种新的富含半胱氨酸的框架，这些框架可能具有新的药理学。最后，芋螺毒素转录本的密码子使用偏好和RNA编辑过程的分析表明，在核酸水平上的半胱氨酸骨架的特定保守性，并提供了新的见解的起源在成熟的毒素区域的序列高变。
Cone snails are predatory marine gastropods characterized by a sophisticated venom apparatus responsible for the biosynthesis and delivery of complex mixtures of cysteine-rich toxin peptides. These conotoxins fold into small highly structured frameworks, allowing them to potently and selectively interact with heterologous ion channels and receptors. Approximately 2,000 toxins from an estimated number of >70,000 bioactive peptides have been identified in the genus Conus to date. Here, we describe a high-resolution interrogation of the transcriptomes (available at www.ddbj.nig.ac.jp) and proteomes of the diverse compartments of the Conus episcopatus venom apparatus. Using biochemical and bioinformatic tools, we found the highest number of conopeptides yet discovered in a single Conus specimen, with 3,305 novel precursor toxin sequences classified into 9 known superfamilies (A, I1, I2, M, O1, O2, S, T, Z), and identified 16 new superfamilies showing unique signal peptide signatures. We were also able to depict the largest population of venom peptides containing the pharmacologically active C-C-CC-C-C inhibitor cystine knot and CC-C-C motifs (168 and 44 toxins, respectively), as well as 208 new conotoxins displaying odd numbers of cysteine residues derived from known conotoxin motifs. Importantly, six novel cysteine-rich frameworks were revealed which may have novel pharmacology. Finally, analyses of codon usage bias and RNA-editing processes of the conotoxin transcripts demonstrate a specific conservation of the cysteine skeleton at the nucleic acid level and provide new insights about the origin of sequence hypervariablity in mature toxin regions.