Safavi-Hemami Helena, Hu Hao, Gorasia Dhana G, Bandyopadhyay Pradip K, Veith Paul D, Young Neil D, Reynolds Eric C, Yandell Mark, Olivera Baldomero M, Purcell Anthony W
Department of Biology and.
Mol Cell Proteomics. 2014 Apr;13(4):938-53. doi: 10.1074/mcp.M113.031351. Epub 2014 Jan 29.
Cone snails are highly successful marine predators that use complex venoms to capture prey. At any given time, hundreds of toxins (conotoxins) are synthesized in the secretory epithelial cells of the venom gland, a long and convoluted organ that can measure 4 times the length of the snail's body. In recent years a number of studies have begun to unveil the transcriptomic, proteomic and peptidomic complexity of the venom and venom glands of a number of cone snail species. By using a combination of DIGE, bottom-up proteomics and next-generation transcriptome sequencing the present study identifies proteins involved in envenomation and conotoxin maturation, significantly extending the repertoire of known (poly)peptides expressed in the venom gland of these remarkable animals. We interrogate the molecular and proteomic composition of different sections of the venom glands of 3 specimens of the fish hunter Conus geographus and demonstrate regional variations in gene expression and protein abundance. DIGE analysis identified 1204 gel spots of which 157 showed significant regional differences in abundance as determined by biological variation analysis. Proteomic interrogation identified 342 unique proteins including those that exhibited greatest fold change. The majority of these proteins also exhibited significant changes in their mRNA expression levels validating the reliability of the experimental approach. Transcriptome sequencing further revealed a yet unknown genetic diversity of several venom gland components. Interestingly, abundant proteins that potentially form part of the injected venom mixture, such as echotoxins, phospholipase A2 and con-ikots-ikots, classified into distinct expression clusters with expression peaking in different parts of the gland. Our findings significantly enhance the known repertoire of venom gland polypeptides and provide molecular and biochemical evidence for the compartmentalization of this organ into distinct functional entities.
芋螺是非常成功的海洋捕食者，它们利用复杂的毒液来捕获猎物。在任何给定时间，毒液腺（一个长而盘绕的器官，长度可达蜗牛身体的4倍）的分泌上皮细胞中会合成数百种毒素（芋螺毒素）。近年来，一些研究已开始揭示多种芋螺物种的毒液和毒液腺在转录组学、蛋白质组学和肽组学方面的复杂性。通过结合使用差异凝胶电泳（DIGE）、自下而上蛋白质组学和新一代转录组测序，本研究确定了参与毒液注入和芋螺毒素成熟的蛋白质，显著扩展了这些非凡动物毒液腺中已知（多）肽的种类。我们研究了3个鱼类捕食者地纹芋螺标本毒液腺不同部位的分子和蛋白质组成，并证明了基因表达和蛋白质丰度的区域差异。DIGE分析确定了1204个凝胶点，其中157个在通过生物学变异分析确定的丰度上显示出显著的区域差异。蛋白质组学研究确定了342种独特蛋白质，包括那些具有最大倍数变化的蛋白质。这些蛋白质中的大多数在mRNA表达水平上也表现出显著变化，验证了实验方法的可靠性。转录组测序进一步揭示了几种毒液腺成分未知的遗传多样性。有趣的是，可能构成注入毒液混合物一部分的丰富蛋白质，如echotoxins、磷脂酶A2和芋螺防御肽，被分类到不同的表达簇中，其表达在腺体的不同部位达到峰值。我们的研究结果显著增加了毒液腺多肽的已知种类，并为该器官划分为不同功能实体提供了分子和生化证据。
