Specialisation of the Venom Gland Proteome in Predatory Cone Snails Reveals Functional Diversification of the Conotoxin Biosynthetic Pathway

Safavi-­Hemami, Helena; Siero, William A.; Gorasia, Dhana G.; Young, Neil D.; Macmillan, David L.; Williamson, Nicholas A.; Purcell, Anthony W.

doi:10.1021/pr1012976

Cited by 41 publications

(45 citation statements)

References 71 publications

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“…We showed that all three enzymes, PDI, PPI B, and BiP, efficiently assist in the oxidative folding of ␣-GI and ␣-ImI. PDI represents one of the most abundant soluble proteins in the venom gland of several cone snail species (16,37) and has previously been shown to improve in vitro folding rates of conotoxin substrates (18). We confirm this finding and further demonstrate the ability of PDI to efficiently unfold disulfide bonds in conotoxins under reducing conditions.…”

Section: Discussionsupporting

confidence: 77%

“…8Bii), with the main PDI isoform migrating at ϳ90 kDa. In a previous study (16), immunoblotting of two-dimensional gels revealed the presence of larger molecular weight isoforms of PDI in the venom glands of C. victoriae and C. novaehollandiae. Whether the 90 kDa band represents a different PDI isoform remains to be determined because proteins excised from BN-PAGE can exhibit deviating migration patterns due to the presence of encasing BN gel matrices.…”

Section: Resultsmentioning

confidence: 76%

“…Although PDI and PPI have been identified in the venom gland of Conus (16) and are known to play a role in the in vitro folding of conotoxins (17,18), their combined effect has not been investigated. We recently sequenced Conus BiP from the venom gland of Conus novaehollandiae and demonstrated it to be highly expressed in the venom glandular cells (16). Whether BiP plays a functional role in the folding of conotoxins was not addressed in our earlier study.…”

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confidence: 99%

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Modulation of Conotoxin Structure and Function Is Achieved through a Multienzyme Complex in the Venom Glands of Cone Snails

Safavi-Hemami

Gorasia

Steiner

et al. 2012

Journal of Biological Chemistry

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Background: Conotoxins can be utilized to investigate enzyme-assisted folding of disulfide-rich peptides. Results: Various ER-resident cone snail enzymes act in concert to accelerate the oxidative folding of conotoxins and modulate their conformation by reconfiguring disulfide connectivities. Conclusion:The folding of conotoxins is a tightly regulated multienzyme-assisted process. Significance: Modulation of the conformation of conotoxins increases their molecular and functional diversity.

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Section: Discussionsupporting

confidence: 77%

Section: Resultsmentioning

confidence: 76%

mentioning

confidence: 99%

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Modulation of Conotoxin Structure and Function Is Achieved through a Multienzyme Complex in the Venom Glands of Cone Snails

Safavi-Hemami

Gorasia

Steiner

et al. 2012

Journal of Biological Chemistry

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“…The milky appeareance is mainly due to the presence of secretory granules ( Fig. 4C) that appear similar to those found in the venom duct of another molluscivorous cone snail, C. victoriae (34). The volume of the injected venom seems to vary according to the size of the animal, and generally 10 -20 l were collected per milking, with six different individuals pooled for our proteomic analysis.…”

Section: Resultssupporting

confidence: 55%

Deep Venomics Reveals the Mechanism for Expanded Peptide Diversity in Cone Snail Venom

Dutertre

Jin

Kaas

et al. 2013

Molecular & Cellular Proteomics

195

316

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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 ϳ 100 gene transcripts can generate thousands of conopeptides in a single species of cone snail. Molecular & Cellular

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“…Two other conopeptides have entered human clinical trials for the treatment of neuropathic pain (12) and others are in preclinical evaluation. Furthermore, numerous fundamental biological studies focused on understanding the maturation of the venom (13), the influence of environment or cone snail development stage on conopeptide expression (14–16) and the phylogenetic relationships between toxins (17,18) have been published.…”

Section: Introductionmentioning

confidence: 99%

ConoServer: updated content, knowledge, and discovery tools in the conopeptide database

Kaas¹,

Yu²,

Jin³

et al. 2011

Nucleic Acids Research

318

371

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ConoServer (http://www.conoserver.org) is a database specializing in the sequences and structures of conopeptides, which are toxins expressed by marine cone snails. Cone snails are carnivorous gastropods, which hunt their prey using a cocktail of toxins that potently subvert nervous system function. The ability of these toxins to specifically target receptors, channels and transporters of the nervous system has attracted considerable interest for their use in physiological research and as drug leads. Since the founding publication on ConoServer in 2008, the number of entries in the database has nearly doubled, the interface has been redesigned and new annotations have been added, including a more detailed description of cone snail species, biological activity measurements and information regarding the identification of each sequence. Automatically updated statistics on classification schemes, three-dimensional structures, conopeptide-bearing species and endoplasmic reticulum signal sequence conservation trends, provide a convenient overview of current knowledge on conopeptides. Transcriptomics and proteomics have began generating massive numbers of new conopeptide sequences, and two dedicated tools have been recently implemented in ConoServer to standardize the analysis of conopeptide precursor sequences and to help in the identification by mass spectrometry of toxins whose sequences were predicted at the nucleic acid level.

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Specialisation of the Venom Gland Proteome in Predatory Cone Snails Reveals Functional Diversification of the Conotoxin Biosynthetic Pathway

Cited by 41 publications

References 71 publications

Modulation of Conotoxin Structure and Function Is Achieved through a Multienzyme Complex in the Venom Glands of Cone Snails

Modulation of Conotoxin Structure and Function Is Achieved through a Multienzyme Complex in the Venom Glands of Cone Snails

Deep Venomics Reveals the Mechanism for Expanded Peptide Diversity in Cone Snail Venom

ConoServer: updated content, knowledge, and discovery tools in the conopeptide database

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