Embryonic Toxin Expression in the Cone Snail Conus victoriae PRIMED TO KILL OR DIVERGENT FUNCTION?

Safavi-Hemami, H; Siero, WA; Kuang, ZH; Williamson, NA; Karas, JA; Page, LR; MacMillan, D; Callaghan, B; Kompella, SN; Adams, DJ; Norton, RS; Purcell, AW

Author(s): Safavi-Hemami, H; Siero, WA; Kuang, ZH; Williamson, NA; Karas, JA; Page, LR; MacMillan, D; Callaghan, B; Kompella, SN; Adams, DJ; Norton, RS; Purcell, AW;
Details: Publication Year 2011-06-24,Volume 286,Issue #25,Page 22546-22557
Journal Title: JOURNAL OF BIOLOGICAL CHEMISTRY
Publication Type: Journal Article
Abstract: 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 alpha- 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 alpha-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.
Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Keywords: NICOTINIC ACETYLCHOLINE-RECEPTORS; PERFORMANCE LIQUID-CHROMATOGRAPHY; ALPHA-CONOTOXINS VC1.1; TORSION ANGLE DYNAMICS; ROOT GANGLION NEURONS; MASS-SPECTROMETRY; POSTTRANSLATIONAL MODIFICATIONS; STRUCTURAL-CHARACTERIZATION; PROTEIN STRUCTURES; CALCIUM-CHANNELS
Publisher's Version: https://doi.org/10.1074/jbc.M110.217703
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2011-06-24 12:00:00