Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, Victoria, 3052, Australia.
Sciences Department, Museum Victoria, G.P.O. Box 666, Melbourne, Victoria, 3001, Australia.
Mar Biotechnol (NY). 2020 Apr;22(2):207-219. doi: 10.1007/s10126-020-09945-8. Epub 2020 Jan 24.
Cnidarians are one of the oldest known animal lineages (ca. 700 million years), with a unique envenomation apparatus to deliver a potent mixture of peptides and proteins. Some peptide toxins from cnidarian venom have proven therapeutic potential. Here, we use a transcriptomic/proteomic strategy to identify sequences with similarity to known venom protein families in the tentacles of the endemic Australian 'speckled anemone' (Oulactis sp.). Illumina RNASeq data were assembled de novo. Annotated sequences in the library were verified by cross-referencing individuals' transcriptomes or protein expression evidence from LC-MS/MS data. Sequences include pore-forming toxins, phospholipases, peptidases, neurotoxins (sodium and potassium channel modulators), cysteine-rich secretory proteins and defensins (antimicrobial peptides). Fewer than 4% of the sequences in the library occurred across the three individuals examined, demonstrating high sequence variability of an individual's arsenal. We searched for actinoporins in Oulactis sp. to assess sequence similarity to the only described toxins (OR-A and -G) for this genus and examined the domain architecture of venom-related peptides and proteins. The novel putative actinoporin of Oulactis sp. has a greater similarity to other species in the Actiniidae family than to O. orientalis. Venom-related sequences have an architecture that occurs in single, repeat or multi-domain combinations of venom-related (e.g. ShK-like) and non-venom (e.g. whey acid protein) domains. This study has produced the first transcriptomes for an endemic Australian sea anemone species and the genus Oulactis, while identifying nearly 400 novel venom-related peptides and proteins for future structural and functional analyses and venom evolution studies.
刺胞动物是已知最古老的动物谱系之一（约 7 亿年），具有独特的毒液输送装置，可输送强效的肽和蛋白质混合物。一些来自刺胞动物毒液的肽毒素已被证明具有治疗潜力。在这里，我们使用转录组/蛋白质组学策略来鉴定与澳大利亚特有“斑点海葵”（Oulactis sp.）触须中已知毒液蛋白家族具有相似性的序列。使用 Illumina RNA-Seq 数据进行从头组装。文库中注释的序列通过交叉引用个体的转录组或 LC-MS/MS 数据中的蛋白质表达证据进行验证。序列包括成孔毒素、磷脂酶、肽酶、神经毒素（钠和钾通道调节剂）、富含半胱氨酸的分泌蛋白和防御素（抗菌肽）。文库中不到 4%的序列在三个个体中都存在，这表明个体的武器库的序列可变性很高。我们在 Oulactis sp. 中搜索了 actinoporins，以评估与该属唯一描述的毒素（OR-A 和 -G）的序列相似性，并检查了与毒液相关的肽和蛋白质的结构域架构。Oulactis sp. 的新型推定的 actinoporin 与 Actiniidae 科的其他物种具有更高的相似性，而不是与 O. orientalis。毒液相关序列具有发生在单个、重复或多结构域组合中的结构域架构，包括毒液相关（例如 ShK 样）和非毒液（例如乳清酸蛋白）结构域。本研究首次产生了澳大利亚特有海葵物种和 Oulactis 属的转录组，同时鉴定了近 400 种新型与毒液相关的肽和蛋白质，用于未来的结构和功能分析以及毒液进化研究。
