UMR 6035 CNRS, Institut de Recherche sur la Biologie de l'Insecte, Faculté des Sciences et Techniques, Université François-Rabelais, Parc Grandmont, 37200 Tours, France.
BMC Genomics. 2010 Dec 7;11:693. doi: 10.1186/1471-2164-11-693.
Parasitic wasps constitute one of the largest group of venomous animals. Although some physiological effects of their venoms are well documented, relatively little is known at the molecular level on the protein composition of these secretions. To identify the majority of the venom proteins of the endoparasitoid wasp Chelonus inanitus (Hymenoptera: Braconidae), we have randomly sequenced 2111 expressed sequence tags (ESTs) from a cDNA library of venom gland. In parallel, proteins from pure venom were separated by gel electrophoresis and individually submitted to a nano-LC-MS/MS analysis allowing comparison of peptides and ESTs sequences.
About 60% of sequenced ESTs encoded proteins whose presence in venom was attested by mass spectrometry. Most of the remaining ESTs corresponded to gene products likely involved in the transcriptional and translational machinery of venom gland cells. In addition, a small number of transcripts were found to encode proteins that share sequence similarity with well-known venom constituents of social hymenopteran species, such as hyaluronidase-like proteins and an Allergen-5 protein.An overall number of 29 venom proteins could be identified through the combination of ESTs sequencing and proteomic analyses. The most highly redundant set of ESTs encoded a protein that shared sequence similarity with a venom protein of unknown function potentially specific of the Chelonus lineage. Venom components specific to C. inanitus included a C-type lectin domain containing protein, a chemosensory protein-like protein, a protein related to yellow-e3 and ten new proteins which shared no significant sequence similarity with known sequences. In addition, several venom proteins potentially able to interact with chitin were also identified including a chitinase, an imaginal disc growth factor-like protein and two putative mucin-like peritrophins.
The use of the combined approaches has allowed to discriminate between cellular and truly venom proteins. The venom of C. inanitus appears as a mixture of conserved venom components and of potentially lineage-specific proteins. These new molecular data enrich our knowledge on parasitoid venoms and more generally, might contribute to a better understanding of the evolution and functional diversity of venom proteins within Hymenoptera.
寄生蜂构成了最大的有毒动物群体之一。尽管它们毒液的一些生理效应已有详细记录，但在分子水平上对这些分泌物的蛋白质组成知之甚少。为了鉴定内寄生蜂Chelonus inanitus（膜翅目：Braconidae）毒液的大多数毒液蛋白，我们从毒液腺的 cDNA 文库中随机测序了 2111 个表达序列标签（EST）。同时，通过凝胶电泳分离纯毒液中的蛋白质，并分别进行纳升液相色谱-串联质谱（nano-LC-MS/MS）分析，比较肽和 EST 序列。
约 60%测序的 EST 编码的蛋白质在质谱中得到证实。其余的 EST 大多对应于毒液腺细胞转录和翻译机制中可能涉及的基因产物。此外，还发现一小部分转录本编码的蛋白质与社会性膜翅目物种的已知毒液成分具有序列相似性，例如透明质酸酶样蛋白和过敏原 5 蛋白。通过 EST 测序和蛋白质组学分析的组合，可以鉴定出 29 种毒液蛋白。EST 编码的高度冗余集编码一种蛋白质，该蛋白质与 Chelonus 谱系特有的未知功能的毒液蛋白具有序列相似性。特定于 C. inanitus 的毒液成分包括一种含有 C 型凝集素结构域的蛋白、一种化学感觉蛋白样蛋白、一种与 yellow-e3 相关的蛋白和 10 种新蛋白，它们与已知序列没有显著的序列相似性。此外，还鉴定出几种可能与几丁质相互作用的毒液蛋白，包括几丁质酶、 imaginal disc growth factor-like 蛋白和两种假定的粘液层蛋白。
联合方法的使用能够区分细胞和真正的毒液蛋白。C. inanitus 的毒液是保守的毒液成分和潜在谱系特异性蛋白的混合物。这些新的分子数据丰富了我们对寄生蜂毒液的认识，更普遍地，可能有助于更好地理解膜翅目毒液蛋白的进化和功能多样性。
