Deep venomics reveals the mechanism for expanded peptide diversity in cone snail venom

Dutertre, Sebastien, Jin, Ai-Hua (Jean), Kaas, Quentin, Jones, Alun, Alewood, Paul F. and Lewis, Richard J. (2013) Deep venomics reveals the mechanism for expanded peptide diversity in cone snail venom. Molecular and Cellular Proteomics, 12 2: 312-329. doi:10.1074/mcp.M112.021469


Author Dutertre, Sebastien
Jin, Ai-Hua (Jean)
Kaas, Quentin
Jones, Alun
Alewood, Paul F.
Lewis, Richard J.
Title Deep venomics reveals the mechanism for expanded peptide diversity in cone snail venom
Journal name Molecular and Cellular Proteomics   Check publisher's open access policy
ISSN 1535-9476
1535-9484
Publication date 2013-02-01
Year available 2012
Sub-type Article (original research)
DOI 10.1074/mcp.M112.021469
Open Access Status DOI
Volume 12
Issue 2
Start page 312
End page 329
Total pages 18
Place of publication Bethesda, MD, United States
Publisher American Society for Biochemistry and Molecular Biology
Language eng
Abstract We report the first integrated proteomic and transcriptomic investigation of a crustacean venom. Remipede crustaceans are the venomous sister group of hexapods, and the venom glands of the remipede Xibalbanus tulumensis express a considerably more complex cocktail of proteins and peptides than previously thought. We identified 32 venom protein families, including 13 novel peptide families that we name xibalbins, four of which lack similarities to any known structural class. Our proteomic data confirm the presence in the venom of 19 of the 32 families. The most highly expressed venom components are serine peptidases, chitinase and six of the xibalbins. The xibalbins represent Inhibitory Cystine Knot peptides (ICK), a double ICK peptide, peptides with a putative Cystine-stabilized α-helix/β-sheet motif, a peptide similar to hairpin-like β-sheet forming antimicrobial peptides, two peptides related to different hormone families, and four peptides with unique structural motifs. Remipede venom components represent the full range of evolutionary recruitment frequencies, from families that have been recruited into many animal venoms (serine peptidases, ICKs), to those having a very narrow taxonomic range (double ICKs), to those unique for remipedes. We discuss the most highly expressed venom components to shed light on their possible functional significance in the predatory and defensive use of remipede venom, and to provide testable ideas for any future bioactivity studies.
Formatted abstract
Cone snails produce highly complex venom comprising mostly small biologically active peptides known as conotoxins or conopeptides. Early estimates that suggested 50–200 venom peptides are produced per species have been recently increased at least 10-fold using advanced mass spectrometry. To uncover the mechanism(s) responsible for generating this impressive diversity, we used an integrated approach combining second-generation transcriptome sequencing with high sensitivity proteomics. From the venom gland transcriptome of Conus marmoreus, a total of 105 conopeptide precursor sequences from 13 gene superfamilies were identified. Over 60% of these precursors belonged to the three gene superfamilies O1, T, and M, consistent with their high levels of expression, which suggests these conotoxins play an important role in prey capture and/or defense. Seven gene superfamilies not previously identified in C. marmoreus, including five novel superfamilies, were also discovered. To confirm the expression of toxins identified at the transcript level, the injected venom of C. marmoreus was comprehensively analyzed by mass spectrometry, revealing 2710 and 3172 peptides using MALDI and ESI-MS, respectively, and 6254 peptides using an ESI-MS TripleTOF 5600 instrument. All conopeptides derived from transcriptomic sequences could be matched to masses obtained on the TripleTOF within 100 ppm accuracy, with 66 (63%) providing MS/MS coverage that unambiguously confirmed these matches. Comprehensive integration of transcriptomic and proteomic data revealed for the first time that the vast majority of the conopeptide diversity arises from a more limited set of genes through a process of variable peptide processing, which generates conopeptides with alternative cleavage sites, heterogeneous post-translational modifications, and highly variable N- and C-terminal truncations. Variable peptide processing is expected to contribute to the evolution of venoms, and explains how a limited set of ∼ 100 gene transcripts can generate thousands of conopeptides in a single species of cone snail.
Keyword ICK
Remipedia
anchialine caves
arthropods
crustaceans
venom
venomics
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ
Additional Notes First Published on November 14, 2012

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2013 Collection
Institute for Molecular Bioscience - Publications
 
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Created: Sat, 19 Jan 2013, 00:42:18 EST by Susan Allen on behalf of Institute for Molecular Bioscience