Citation

Hatakeyama T, Kishigawa A, Unno H. Toxicon 2021; ePub(ePub): ePub.

Copyright

(Copyright © 2021, Elsevier Publishing)

DOI

10.1016/j.toxicon.2021.08.006

PMID

unavailable

Abstract

Various proteins are involved in fish venom toxicity, but limited information is available regarding their structure and mode of action. Here, we analyzed RNA transcripts in the dorsal spine of the devil stinger Inimicus japonicus using next-generation sequencing (NGS), and identified two putative protein toxins, a natterin-like protein (Ij-natterin) and a phospholipase A(2) (Ij-PLA(2)), as well as a previously reported stonustoxin-like protein. The deduced amino acid sequence of Ij-natterin suggested that it acts as a pore-forming toxin through the cooperation of the N-terminal lectin-like domain and the C-terminal pore-forming domain. Ij-PLA(2) showed significant homology with secreted Ca(2+)-dependent PLA(2)s from snake venom and mammals (sPLA(2)-I/II). The recombinant Ij-PLA(2) protein exhibited PLA(2) activity in the absence of Ca(2+), in contrast to canonical sPLA(2)-I/II. Comparison of the amino acid sequences of Ij-PLA(2) with the other sPLA(2)-I/II suggests that the C-terminal extended peptide region of Ij-PLA(2) is involved in its Ca(2+)-independent activity.

Language: en

Keywords

fish venom; Inimicus japonicus; natterin; next generation sequencing; phospholipase A(2); pore-forming protein