Identification of unusual peptides with new Cys frameworks in the venom of the cold-water sea anemone Cnidopus japonicus

Abstract

Sea anemones (Actiniaria) are intensely popular objects of study in venomics. Order Actiniaria includes more than 1,000 species, thus presenting almost unlimited opportunities for the discovery of novel biologically active molecules. The venoms of cold-water sea anemones are studied far less than the venoms of tropical sea anemones. In this work, we analysed the molecular venom composition of the cold-water sea anemone Cnidopus japonicus. Two sets of NGS data from two species revealed molecules belonging to a variety of structural classes, including neurotoxins, toxin-like molecules, linear polypeptides (Cys-free), enzymes, and cytolytics. High-throughput proteomic analyses identified 27 compounds that were present in the venoms. Some of the toxin-like polypeptides exhibited novel Cys frameworks. To characterise their function in the venom, we heterologously expressed 3 polypeptides with unusual Cys frameworks (designated CjTL7, CjTL8, and AnmTx Cj 1c-1) in E. coli. Toxicity tests revealed that the CjTL8 polypeptide displays strong crustacean-specific toxicity, while AnmTx Cj 1c-1 is toxic to both crustaceans and insects. Thus, an improved NGS data analysis algorithm assisted in the identification of toxins with unusual Cys frameworks showing no homology according to BLAST. Our study shows the advantage of combining omics analysis with functional tests for active polypeptide discovery.

Therapeutics Approaches of Invertebrate Animal Toxins: A Review

“…Actinoporin show consistent different hemolytic activity in all their representatives [11]. Sea anemones H. crispa is a pore-forming toxin belongs to actinoporins that show hemolytic activity [12]. Pocilopotoxin-Spi1 toxin (α-PCTX-Spi1) isolated from Stylophora pistillata shows hemolytic activity (table 1) [13].…”

“…These successfully control angiogenesis and inhibit cell proliferation in vitro cancer cell cultures. These toxins displayed anticancer effects and inhibit the growth and proliferation of tumor and cancerous cells [1]. A number of toxins purified from anemones, centipedes, bees, or wasps, hornets, snails, spider and scorpion and sea, fish, toads, fry, and the snake has been isolated and screened for their anticancer effects.…”

Discovery of novel peptide neurotoxins from sea anemone species

“…Few studies have reported the transcriptome sequencing of sea anemone venom and identification of venom-related peptides and proteins, which can be used for their structural and functional analyses and venom evolution in the fu-ture (Table 4, Ref. [18,46,87,109,135,136,[141][142][143]) [132,136]. Tentacles are ideal for transcriptomics analysis because the number and level of transcripts encoded by sea anemone peptide neurotoxins from tentacles are much greater than those encoded by sea anemone peptide neurotoxins from other tissues [132].…”

Coelenterate Toxins, Its Pharmaceutical and Therapeutic Effects

“…Sea anemone Urticinagrebelnyi contain Ugr 9-129 amino acid peptides cross-linked by two disulfide bridges shows analgesic activity [52] Ueq 12-1 is a unique peptide potentiator of the TRPA1 receptor. This is isolated from Urticinaeques that produces analgesic activity [53]. The cold-water sea anemone Cnidopus japonicas contain neurotoxins, toxin-like molecules, linear polypeptides (Cys-free), enzymes, which show analgesic effects [60] Sea anemone contains one bioactive peptide named α-AnmTxUeq 12-1 (Ueq 12-1) (fig.…”