TY - JOUR

T1 - Embryonic toxin expression in the cone snail Conus victoriae

T2 - primed to kill or divergent function?

AU - Safavi-Hemami, Helena

AU - Siero, William A

AU - Kuang, Zhihe

AU - Williamson, Nicholas A

AU - Karas, John A

AU - Page, Louise R

AU - MacMillan, David

AU - Callaghan, Brid

AU - Kompella, Shiva Nag

AU - Adams, David J

AU - Norton, Raymond S

AU - Purcell, Anthony W

PY - 2011/6/24

Y1 - 2011/6/24

N2 - 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.

AB - 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.

KW - Amino Acid Sequence

KW - Animals

KW - Conotoxins/chemistry

KW - Conus Snail/anatomy & histology

KW - Embryo, Nonmammalian/metabolism

KW - Gene Expression Regulation

KW - Mass Spectrometry

KW - Models, Molecular

KW - Molecular Sequence Data

KW - Neurons/metabolism

KW - Peptide Fragments/chemistry

KW - Protein Conformation

KW - RNA, Messenger/genetics

KW - Sequence Alignment

U2 - 10.1074/jbc.M110.217703

DO - 10.1074/jbc.M110.217703

M3 - Journal article

C2 - 21504902

VL - 286

SP - 22546

EP - 22557

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 25

ER -