PDF(Pubmed)
Abstract：
Venom plays a crucial role in the defense and predation of venomous animals. Spiders (Araneae) are among the most successful predators and have a fascinating venom composition. Their venom mainly contains disulfide-rich peptides and large proteins. Here, we analyzed spider venom protein families, utilizing transcriptomic and genomic data, and highlighted their similarities and differences. We show that spiders have specific combinations of toxins for better predation and defense, typically comprising a core toxin expressed alongside several auxiliary toxins. Among them, the CAP superfamily is widely distributed and highly expressed in web-building Araneoidea spiders. Our analysis of evolutionary relationships revealed four subfamilies (subA-subD) of the CAP superfamily that differ in structure and potential functions. CAP proteins are composed of a conserved CAP domain and diverse C-terminal domains. CAP subC shares similar domains with the snake ion channel regulator svCRISP proteins, while CAP subD possesses a sequence similar to that of insect venom allergen 5 (Ag5). Furthermore, we show that gene duplication and selective expression lead to increased expression of CAP subD, making it a core member of the CAP superfamily. This study sheds light on the functional diversity of CAP subfamilies and their evolutionary history, which has important implications for fully understanding the composition of spider venom proteins and the core toxin components of web-building spiders.
摘要：
毒液在有毒动物的防御和捕食中起着至关重要的作用。蜘蛛（Araneae）是最成功的捕食者之一，具有迷人的毒液成分。它们的毒液主要含有富含二硫键的肽和大蛋白质。这里,我们分析了蜘蛛毒蛋白家族，利用转录组和基因组数据，并强调了它们的异同。我们证明蜘蛛具有特定的毒素组合，可以更好地捕食和防御，通常包含与几种辅助毒素一起表达的核心毒素。其中,CAP超家族在网络构建的Araneoidea蜘蛛中分布广泛，表达很高。我们对进化关系的分析揭示了CAP超家族的四个亚家族（subA-subD），它们的结构和潜在功能不同。CAP蛋白由保守的CAP结构域和不同的C末端结构域组成。CAPsubC与蛇离子通道调节蛋白svCRISP共享相似的结构域，而CAPsubD具有与昆虫毒液过敏原5（Ag5）相似的序列。此外，我们表明基因复制和选择性表达导致CAPsubD的表达增加，使其成为CAP超家族的核心成员.本研究揭示了CAP亚家族的功能多样性及其进化史,这对于充分理解蜘蛛毒液蛋白的组成和网络构建蜘蛛的核心毒素成分具有重要意义。
