Protein Structure and Folding
Embryonic Toxin Expression in the Cone Snail Conus victoriae: PRIMED TO KILL OR DIVERGENT FUNCTION?*

https://doi.org/10.1074/jbc.M110.217703Get rights and content
Under a Creative Commons license
open access

Predatory marine cone snails (genus Conus) utilize complex venoms mainly composed of small peptide toxins that target voltage- and ligand-gated ion channels in their prey. Although the venoms of a number of cone snail species have been intensively profiled and functionally characterized, nothing is known about the initiation of venom expression at an early developmental stage. Here, we report on the expression of venom mRNA in embryos of Conus victoriae and the identification of novel α- and O-conotoxin sequences. Embryonic toxin mRNA expression is initiated well before differentiation of the venom gland, the organ of venom biosynthesis. Structural and functional studies revealed that the embryonic α-conotoxins exhibit the same basic three-dimensional structure as the most abundant adult toxin but significantly differ in their neurological targets. Based on these findings, we postulate that the venom repertoire of cone snails undergoes ontogenetic changes most likely reflecting differences in the biotic interactions of these animals with their prey, predators, or competitors. To our knowledge, this is the first study to show toxin mRNA transcripts in embryos, a finding that extends our understanding of the early onset of venom expression in animals and may suggest alternative functions of peptide toxins during development.

Embryo
Mass Spectrometry (MS)
Neurotoxin
NMR
Toxins
Toxin Ontogeny
Toxin Structure Function

Cited by (0)

The nucleotide sequence(s) reported in this paper has been submitted to the Gen-BankTM/EBI Data Bank with accession number(s) GU046308, GU046309, JF433900, JF433901, JF433902, JF433903, JF433904, JF433905, JF433906, JF433907, JF433908, JF433909, JF433910.

*

This work was supported in part by Australian Research Council Grant DP110101331 (to A. W. P. and N. A. W.).

The on-line version of this article (available at http://www.jbc.org) contains supplemental Figs. 1–4 and Table 1.

1

Professorial fellow of the Australian Research Council.

2

Recipient of a National Health and Medical Research Council of Australia principal research fellowship.