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Zheng JW, Lu Y, Yang YF, Huang D, Li DW, Wang X, Gao Y, Yang WD, Guan Y, Li HY. Systematic dissection of genomic features determining the vast diversity of conotoxins. BMC Genomics 2023; 24:598. [PMID: 37814244 PMCID: PMC10561478 DOI: 10.1186/s12864-023-09689-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 09/20/2023] [Indexed: 10/11/2023] Open
Abstract
BACKGROUND Conus, a highly diverse species of venomous predators, has attracted significant attention in neuroscience and new drug development due to their rich collection of neuroactive peptides called conotoxins. Recent advancements in transcriptome, proteome, and genome analyses have facilitated the identification of conotoxins within Conus' venom glands, providing insights into the genetic features and evolutionary patterns of conotoxin genes. However, the underlying mechanism behind the extraordinary hypervariability of conotoxins remains largely unknown. RESULTS We analyzed the transcriptomes of 34 Conus species, examining various tissues such as the venom duct, venom bulb, and salivary gland, leading to the identification of conotoxin genes. Genetic variation analysis revealed that a subset of these genes (15.78% of the total) in Conus species underwent positive selection (Ka/Ks > 1, p < 0.01). Additionally, we reassembled and annotated the genome of C. betulinus, uncovering 221 conotoxin-encoding genes. These genes primarily consisted of three exons, with a significant portion showing high transcriptional activity in the venom ducts. Importantly, the flanking regions and adjacent introns of conotoxin genes exhibited a higher prevalence of transposon elements, suggesting their potential contribution to the extensive variability observed in conotoxins. Furthermore, we detected genome duplication in C. betulinus, which likely contributed to the expansion of conotoxin gene numbers. Interestingly, our study also provided evidence of introgression among Conus species, indicating that interspecies hybridization may have played a role in shaping the evolution of diverse conotoxin genes. CONCLUSIONS This study highlights the impact of adaptive evolution and introgressive hybridization on the genetic diversity of conotoxin genes and the evolution of Conus. We also propose a hypothesis suggesting that transposable elements might significantly contribute to the remarkable diversity observed in conotoxins. These findings not only enhance our understanding of peptide genetic diversity but also present a novel approach for peptide bioengineering.
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Affiliation(s)
- Jian-Wei Zheng
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
- College of Food Science and Engineering, Foshan University of Science and Technology, Foshan, 528231, China
| | - Yang Lu
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Yu-Feng Yang
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Dan Huang
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Da-Wei Li
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Xiang Wang
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Yang Gao
- Gulou Hospital, Nanjing University, Nanjing, China
| | - Wei-Dong Yang
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China
| | - Yuanfang Guan
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, USA
| | - Hong-Ye Li
- Key Laboratory of Aquatic Eutrophication and Control of Harmful Algal Blooms of Guangdong Higher Education Institute, College of Life Science and Technology, Jinan University, Guangzhou, 510632, China.
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Fedosov A, Zaharias P, Puillandre N. A phylogeny-aware approach reveals unexpected venom components in divergent lineages of cone snails. Proc Biol Sci 2021; 288:20211017. [PMID: 34229491 PMCID: PMC8261202 DOI: 10.1098/rspb.2021.1017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/11/2021] [Indexed: 12/31/2022] Open
Abstract
Marine gastropods of the genus Conus are renowned for their remarkable diversity and deadly venoms. While Conus venoms are increasingly well studied for their biomedical applications, we know surprisingly little about venom composition in other lineages of Conidae. We performed comprehensive venom transcriptomic profiling for Conasprella coriolisi and Pygmaeconus traillii, first time for both respective genera. We complemented reference-based transcriptome annotation by a de novo toxin prediction guided by phylogeny, which involved transcriptomic data on two additional 'divergent' cone snail lineages, Profundiconus, and Californiconus. We identified toxin clusters (SSCs) shared among all or some of the four analysed genera based on the identity of the signal region-a molecular tag present in toxins. In total, 116 and 98 putative toxins represent 29 and 28 toxin gene superfamilies in Conasprella and Pygmaeconus, respectively; about quarter of these only found by semi-manual annotation of the SSCs. Two rare gene superfamilies, originally identified from fish-hunting cone snails, were detected outside Conus rather unexpectedly, so we further investigated their distribution across Conidae radiation. We demonstrate that both these, in fact, are ubiquitous in Conidae, sometimes with extremely high expression. Our findings demonstrate how a phylogeny-aware approach circumvents methodological caveats of similarity-based transcriptome annotation.
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Affiliation(s)
- Alexander Fedosov
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky Prospect 33, 119071 Moscow, Russian Federation
- Institut Systématique Evolution Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP 26, 75005 Paris, France
| | - Paul Zaharias
- Institut Systématique Evolution Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP 26, 75005 Paris, France
- Department of Computer Science, University of Illinois Urbana-Champaign, Urbana, IL 61801, USA
| | - Nicolas Puillandre
- Institut Systématique Evolution Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, 57 rue Cuvier, CP 26, 75005 Paris, France
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3
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Padilla A, Dovell S, Chesnokov O, Hoggard M, Oleinikov AV, Marí F. Conus venom fractions inhibit the adhesion of Plasmodium falciparum erythrocyte membrane protein 1 domains to the host vascular receptors. J Proteomics 2020; 234:104083. [PMID: 33373718 DOI: 10.1016/j.jprot.2020.104083] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/28/2020] [Accepted: 12/20/2020] [Indexed: 11/16/2022]
Abstract
Using high-throughput BioPlex assays, we determined that six fractions from the venom of Conus nux inhibit the adhesion of various recombinant PfEMP-1 protein domains (PF08_0106 CIDR1α3.1, PF11_0521 DBL2β3, and PFL0030c DBL3X and DBL5e) to their corresponding receptors (CD36, ICAM-1, and CSA, respectively). The protein domain-receptor interactions permit P. falciparum-infected erythrocytes (IE) to evade elimination in the spleen by adhering to the microvasculature in various organs including the placenta. The sequences for the main components of the fractions, determined by tandem mass spectrometry, yielded four T-superfamily conotoxins, one (CC-Loop-CC) with I-IV, II-III connectivity and three (CC-Loop-CXaaC) with a I-III, II-IV connectivity. The 3D structure for one of the latter, NuxVA = GCCPAPLTCHCVIY, revealed a novel scaffold defined by double turns forming a hairpin-like structure stabilized by the two disulfide bonds. Two other main fraction components were a miniM conotoxin, and a O2-superfamily conotoxin with cysteine framework VI/VII. This study is the first one of its kind suggesting the use of conotoxins for developing pharmacological tools for anti-adhesion adjunct therapy against malaria. Similarly, mitigation of emerging diseases like AIDS and COVID-19, can also benefit from conotoxins as inhibitors of protein-protein interactions as treatment. BIOLOGICAL SIGNIFICANCE: Among the 850+ species of cone snail species there are hundreds of thousands of diverse venom exopeptides that have been selected throughout several million years of evolution to capture prey and deter predators. They do so by targeting several surface proteins present in target excitable cells. This immense biomolecular library of conopeptides can be explored for potential use as therapeutic leads against persistent and emerging diseases affecting non-excitable systems. We aim to expand the pharmacological reach of conotoxins/conopeptides by revealing their in vitro capacity to disrupt protein-protein and protein-polysaccharide interactions that directly contribute to pathology of Plasmodium falciparum malaria. This is significant for severe forms of malaria, which might be deadly even after treated with current parasite-killing drugs because of persistent cytoadhesion of P. falciparum infected erythrocytes even when parasites within red blood cells are dead. Anti-adhesion adjunct drugs would de-sequester or prevent additional sequestration of infected erythrocytes and may significantly improve survival of malaria patients. These results provide a lead for further investigations into conotoxins and other venom peptides as potential candidates for anti-adhesion or blockade-therapies. This study is the first of its kind and it suggests that conotoxins can be developed as pharmacological tools for anti-adhesion adjunct therapy against malaria. Similarly, mitigation of emerging diseases like AIDS and COVID-19, can also benefit from conotoxins as potential inhibitors of protein-protein interactions as treatment.
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Affiliation(s)
- Alberto Padilla
- Department of Biological Sciences, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA
| | - Sanaz Dovell
- Department of Chemistry & Biochemistry, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA
| | - Olga Chesnokov
- Department of Biomedical Science, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA
| | - Mickelene Hoggard
- Chemical Sciences Division, Hollings Marine Laboratory, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, SC 29412, USA
| | - Andrew V Oleinikov
- Department of Biomedical Science, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL 33431, USA.
| | - Frank Marí
- Chemical Sciences Division, Hollings Marine Laboratory, National Institute of Standards and Technology, 331 Fort Johnson Road, Charleston, SC 29412, USA.
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Lu A, Watkins M, Li Q, Robinson SD, Concepcion GP, Yandell M, Weng Z, Olivera BM, Safavi-Hemami H, Fedosov AE. Transcriptomic Profiling Reveals Extraordinary Diversity of Venom Peptides in Unexplored Predatory Gastropods of the Genus Clavus. Genome Biol Evol 2020; 12:684-700. [PMID: 32333764 PMCID: PMC7259678 DOI: 10.1093/gbe/evaa083] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/20/2020] [Indexed: 12/21/2022] Open
Abstract
Predatory gastropods of the superfamily Conoidea number over 12,000 living species. The evolutionary success of this lineage can be explained by the ability of conoideans to produce complex venoms for hunting, defense, and competitive interactions. Whereas venoms of cone snails (family Conidae) have become increasingly well studied, the venoms of most other conoidean lineages remain largely uncharacterized. In the present study, we present the venom gland transcriptomes of two species of the genus Clavus that belong to the family Drilliidae. Venom gland transcriptomes of two specimens of Clavus canalicularis and two specimens of Clavus davidgilmouri were analyzed, leading to the identification of a total of 1,176 putative venom peptide toxins (drillipeptides). Based on the combined evidence of secretion signal sequence identity, entire precursor similarity search (BLAST), and the orthology inference, putative Clavus toxins were assigned to 158 different gene families. The majority of identified transcripts comprise signal, pro-, mature peptide, and post-regions, with a typically short (<50 amino acids) and cysteine-rich mature peptide region. Thus, drillipeptides are structurally similar to conotoxins. However, convincing homology with known groups of Conus toxins was only detected for very few toxin families. Among these are Clavus counterparts of Conus venom insulins (drillinsulins), porins (drilliporins), and highly diversified lectins (drillilectins). The short size of most drillipeptides and structural similarity to conotoxins were unexpected, given that most related conoidean gastropod families (Terebridae and Turridae) possess longer mature peptide regions. Our findings indicate that, similar to conotoxins, drillipeptides may represent a valuable resource for future pharmacological exploration.
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Affiliation(s)
- Aiping Lu
- Department of Central Laboratory, Shanghai Tenth People’s Hospital of Tongji University, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | | | - Qing Li
- Eccles Institute of Human Genetics, University of Utah
- High-Throughput Genomics and Bioinformatic Analysis Shared Resource, Huntsman Cancer Institute, University of Utah
| | | | - Gisela P Concepcion
- Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines
| | - Mark Yandell
- Eccles Institute of Human Genetics, University of Utah
- Utah Center for Genetic Discovery, University of Utah
| | - Zhiping Weng
- Department of Central Laboratory, Shanghai Tenth People’s Hospital of Tongji University, School of Life Sciences and Technology, Tongji University, Shanghai, China
- Program in Bioinformatics and Integrative Biology, University of Massachusetts Medical School
| | | | - Helena Safavi-Hemami
- Department of Biochemistry, University of Utah
- Department of Biology, University of Copenhagen, Denmark
| | - Alexander E Fedosov
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Science, Moscow, Russia
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Venom Diversity and Evolution in the Most Divergent Cone Snail Genus Profundiconus. Toxins (Basel) 2019; 11:toxins11110623. [PMID: 31661832 PMCID: PMC6891753 DOI: 10.3390/toxins11110623] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 10/24/2019] [Accepted: 10/24/2019] [Indexed: 01/02/2023] Open
Abstract
Profundiconus is the most divergent cone snail genus and its unique phylogenetic position, sister to the rest of the family Conidae, makes it a key taxon for examining venom evolution and diversity. Venom gland and foot transcriptomes of Profundiconus cf. vaubani and Profundiconus neocaledonicus were de novo assembled, annotated, and analyzed for differential expression. One hundred and thirty-seven venom components were identified from P. cf. vaubani and 82 from P. neocaledonicus, with only four shared by both species. The majority of the transcript diversity was composed of putative peptides, including conotoxins, profunditoxins, turripeptides, insulin, and prohormone-4. However, there were also a significant percentage of other putative venom components such as chymotrypsin and L-rhamnose-binding lectin. The large majority of conotoxins appeared to be from new gene superfamilies, three of which are highly different from previously reported venom peptide toxins. Their low conotoxin diversity and the type of insulin found suggested that these species, for which no ecological information are available, have a worm or molluscan diet associated with a narrow dietary breadth. Our results indicate that Profundiconus venom is highly distinct from that of other cone snails, and therefore important for examining venom evolution in the Conidae family.
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Jin AH, Muttenthaler M, Dutertre S, Himaya SWA, Kaas Q, Craik DJ, Lewis RJ, Alewood PF. Conotoxins: Chemistry and Biology. Chem Rev 2019; 119:11510-11549. [PMID: 31633928 DOI: 10.1021/acs.chemrev.9b00207] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The venom of the marine predatory cone snails (genus Conus) has evolved for prey capture and defense, providing the basis for survival and rapid diversification of the now estimated 750+ species. A typical Conus venom contains hundreds to thousands of bioactive peptides known as conotoxins. These mostly disulfide-rich and well-structured peptides act on a wide range of targets such as ion channels, G protein-coupled receptors, transporters, and enzymes. Conotoxins are of interest to neuroscientists as well as drug developers due to their exquisite potency and selectivity, not just against prey but also mammalian targets, thereby providing a rich source of molecular probes and therapeutic leads. The rise of integrated venomics has accelerated conotoxin discovery with now well over 10,000 conotoxin sequences published. However, their structural and pharmacological characterization lags considerably behind. In this review, we highlight the diversity of new conotoxins uncovered since 2014, their three-dimensional structures and folds, novel chemical approaches to their syntheses, and their value as pharmacological tools to unravel complex biology. Additionally, we discuss challenges and future directions for the field.
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Affiliation(s)
- Ai-Hua Jin
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Markus Muttenthaler
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia.,Institute of Biological Chemistry, Faculty of Chemistry , University of Vienna , 1090 Vienna , Austria
| | - Sebastien Dutertre
- Département des Acides Amines, Peptides et Protéines, Unité Mixte de Recherche 5247, Université Montpellier 2-Centre Nationale de la Recherche Scientifique , Institut des Biomolécules Max Mousseron , Place Eugène Bataillon , 34095 Montpellier Cedex 5 , France
| | - S W A Himaya
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Quentin Kaas
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - David J Craik
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Richard J Lewis
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
| | - Paul F Alewood
- Institute for Molecular Bioscience , The University of Queensland , Brisbane Queensland 4072 , Australia
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Conotoxin Diversity in the Venom Gland Transcriptome of the Magician's Cone, Pionoconus magus. Mar Drugs 2019; 17:md17100553. [PMID: 31569823 PMCID: PMC6835573 DOI: 10.3390/md17100553] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 09/24/2019] [Indexed: 12/14/2022] Open
Abstract
The transcriptomes of the venom glands of two individuals of the magician’s cone, Pionoconus magus, from Okinawa (Japan) were sequenced, assembled, and annotated. In addition, RNA-seq raw reads available at the SRA database from one additional specimen of P. magus from the Philippines were also assembled and annotated. The total numbers of identified conotoxin precursors and hormones per specimen were 118, 112, and 93. The three individuals shared only five identical sequences whereas the two specimens from Okinawa had 30 sequences in common. The total number of distinct conotoxin precursors and hormones for P. magus was 275, and were assigned to 53 conotoxin precursor and hormone superfamilies, two of which were new based on their divergent signal region. The superfamilies that had the highest number of precursors were M (42), O1 (34), T (27), A (18), O2 (17), and F (13), accounting for 55% of the total diversity. The D superfamily, previously thought to be exclusive of vermivorous cones was found in P. magus and contained a highly divergent mature region. Similarly, the A superfamily alpha 4/3 was found in P. magus despite the fact that it was previously postulated to be almost exclusive of the genus Rhombiconus. Differential expression analyses of P. magus compared to Chelyconus ermineus, the only fish-hunting cone from the Atlantic Ocean revealed that M and A2 superfamilies appeared to be more expressed in the former whereas the O2 superfamily was more expressed in the latter.
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Mendoza CB, Masacupan DJM, Batoctoy DCR, Yu ET, Lluisma AO, Salvador‐Reyes LA. Conomarphins cause paralysis in mollusk: Critical and tunable structural elements for bioactivity. J Pept Sci 2019; 25:e3179. [DOI: 10.1002/psc.3179] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 05/08/2019] [Accepted: 05/10/2019] [Indexed: 01/09/2023]
Affiliation(s)
- Charmaine B. Mendoza
- Marine Science InstituteUniversity of the Philippines, Diliman Quezon City Philippines
| | | | | | - Eizadora T. Yu
- Institute of ChemistryUniversity of the Philippines, Diliman Quezon City Philippines
- Philippine Genome CenterUniversity of the Philippines Diliman Quezon City Philippines
| | - Arturo O. Lluisma
- Marine Science InstituteUniversity of the Philippines, Diliman Quezon City Philippines
- Philippine Genome CenterUniversity of the Philippines Diliman Quezon City Philippines
| | - Lilibeth A. Salvador‐Reyes
- Marine Science InstituteUniversity of the Philippines, Diliman Quezon City Philippines
- Philippine Genome CenterUniversity of the Philippines Diliman Quezon City Philippines
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Li Q, Watkins M, Robinson SD, Safavi-Hemami H, Yandell M. Discovery of Novel Conotoxin Candidates Using Machine Learning. Toxins (Basel) 2018; 10:toxins10120503. [PMID: 30513724 PMCID: PMC6315676 DOI: 10.3390/toxins10120503] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/12/2018] [Accepted: 11/22/2018] [Indexed: 12/24/2022] Open
Abstract
Cone snails (genus Conus) are venomous marine snails that inject prey with a lethal cocktail of conotoxins, small, secreted, and cysteine-rich peptides. Given the diversity and often high affinity for their molecular targets, consisting of ion channels, receptors or transporters, many conotoxins have become invaluable pharmacological probes, drug leads, and therapeutics. Transcriptome sequencing of Conus venom glands followed by de novo assembly and homology-based toxin identification and annotation is currently the state-of-the-art for discovery of new conotoxins. However, homology-based search techniques, by definition, can only detect novel toxins that are homologous to previously reported conotoxins. To overcome these obstacles for discovery, we have created ConusPipe, a machine learning tool that utilizes prominent chemical characters of conotoxins to predict whether a certain transcript in a Conus transcriptome, which has no otherwise detectable homologs in current reference databases, is a putative conotoxin. By using ConusPipe on RNASeq data of 10 species, we report 5148 new putative conotoxin transcripts that have no homologues in current reference databases. 896 of these were identified by at least three out of four models used. These data significantly expand current publicly available conotoxin datasets and our approach provides a new computational avenue for the discovery of novel toxin families.
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Affiliation(s)
- Qing Li
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
- Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA.
| | - Maren Watkins
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
| | - Samuel D Robinson
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
| | - Helena Safavi-Hemami
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA.
- Department of Biochemistry, University of Utah, Salt Lake City, UT 84112, USA.
| | - Mark Yandell
- Eccles Institute of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA.
- USTAR Center for Genetic Discovery, University of Utah, Salt Lake City, UT 84112, USA.
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Fu Y, Li C, Dong S, Wu Y, Zhangsun D, Luo S. Discovery Methodology of Novel Conotoxins from Conus Species. Mar Drugs 2018; 16:md16110417. [PMID: 30380764 PMCID: PMC6266589 DOI: 10.3390/md16110417] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 10/21/2018] [Accepted: 10/25/2018] [Indexed: 12/17/2022] Open
Abstract
Cone snail venoms provide an ideal resource for neuropharmacological tools and drug candidates discovery, which have become a research hotspot in neuroscience and new drug development. More than 1,000,000 natural peptides are produced by cone snails, but less than 0.1% of the estimated conotoxins has been characterized to date. Hence, the discovery of novel conotoxins from the huge conotoxin resources with high-throughput and sensitive methods becomes a crucial key for the conotoxin-based drug development. In this review, we introduce the discovery methodology of new conotoxins from various Conus species. It focuses on obtaining full N- to C-terminal sequences, regardless of disulfide bond connectivity through crude venom purification, conotoxin precusor gene cloning, venom duct transcriptomics, venom proteomics and multi-omic methods. The protocols, advantages, disadvantages, and developments of different approaches during the last decade are summarized and the promising prospects are discussed as well.
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Affiliation(s)
- Ying Fu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Cheng Li
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Shuai Dong
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Yong Wu
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Dongting Zhangsun
- Key Laboratory of Tropical Biological Resources, Ministry of Education, Hainan University, Haikou 570228, China.
| | - Sulan Luo
- Key Laboratory for Marine Drugs of Haikou, Hainan University, Haikou 570228, China.
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Abalde S, Tenorio MJ, Afonso CML, Zardoya R. Conotoxin Diversity in Chelyconus ermineus (Born, 1778) and the Convergent Origin of Piscivory in the Atlantic and Indo-Pacific Cones. Genome Biol Evol 2018; 10:2643-2662. [PMID: 30060147 PMCID: PMC6178336 DOI: 10.1093/gbe/evy150] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2018] [Indexed: 12/27/2022] Open
Abstract
The transcriptome of the venom duct of the Atlantic piscivorous cone species Chelyconus ermineus (Born, 1778) was determined. The venom repertoire of this species includes at least 378 conotoxin precursors, which could be ascribed to 33 known and 22 new (unassigned) protein superfamilies, respectively. Most abundant superfamilies were T, W, O1, M, O2, and Z, accounting for 57% of all detected diversity. A total of three individuals were sequenced showing considerable intraspecific variation: each individual had many exclusive conotoxin precursors, and only 20% of all inferred mature peptides were common to all individuals. Three different regions (distal, medium, and proximal with respect to the venom bulb) of the venom duct were analyzed independently. Diversity (in terms of number of distinct members) of conotoxin precursor superfamilies increased toward the distal region whereas transcripts detected toward the proximal region showed higher expression levels. Only the superfamilies A and I3 showed statistically significant differential expression across regions of the venom duct. Sequences belonging to the alpha (motor cabal) and kappa (lightning-strike cabal) subfamilies of the superfamily A were mainly detected in the proximal region of the venom duct. The mature peptides of the alpha subfamily had the α4/4 cysteine spacing pattern, which has been shown to selectively target muscle nicotinic-acetylcholine receptors, ultimately producing paralysis. This function is performed by mature peptides having a α3/5 cysteine spacing pattern in piscivorous cone species from the Indo-Pacific region, thereby supporting a convergent evolution of piscivory in cones.
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Affiliation(s)
- Samuel Abalde
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
| | - Manuel J Tenorio
- Departamento CMIM y Q. Inorgánica-INBIO, Facultad de Ciencias, Universidad de Cadiz, Puerto Real, Spain
| | - Carlos M L Afonso
- Fisheries, Biodiversity and Conervation Group, Centre of Marine Sciences (CCMAR), Universidade do Algarve, Campus de Gambelas, Faro, Portugal
| | - Rafael Zardoya
- Departamento de Biodiversidad y Biología Evolutiva, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
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Prashanth JR, Dutertre S, Lewis RJ. Pharmacology of predatory and defensive venom peptides in cone snails. MOLECULAR BIOSYSTEMS 2018; 13:2453-2465. [PMID: 29090697 DOI: 10.1039/c7mb00511c] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cone snails are predatory gastropods whose neurotoxic venom peptides (conotoxins) have been extensively studied for pharmacological probes, venom evolution mechanisms and potential therapeutics. Conotoxins have a wide range of structural and functional classes that continue to undergo accelerated evolution that underlies the rapid expansion of the genus over their short evolutionary history. A number of pharmacological classes, driven by separately evolved defensive and predatory venoms, have been hypothesised to facilitate shifts in prey that exemplify the adaptability of cone snails. Here we provide an overview of these pharmacological families and discuss their ecological roles and evolutionary impact.
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Affiliation(s)
- Jutty Rajan Prashanth
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, St. Lucia, 4072, Australia.
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13
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Aird SD, Arora J, Barua A, Qiu L, Terada K, Mikheyev AS. Population Genomic Analysis of a Pitviper Reveals Microevolutionary Forces Underlying Venom Chemistry. Genome Biol Evol 2018; 9:2640-2649. [PMID: 29048530 PMCID: PMC5737360 DOI: 10.1093/gbe/evx199] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2017] [Indexed: 12/24/2022] Open
Abstract
Venoms are among the most biologically active secretions known, and are commonly believed to evolve under extreme positive selection. Many venom gene families, however, have undergone duplication, and are often deployed in doses vastly exceeding the LD50 for most prey species, which should reduce the strength of positive selection. Here, we contrast these selective regimes using snake venoms, which consist of rapidly evolving protein formulations. Though decades of extensive studies have found that snake venom proteins are subject to strong positive selection, the greater action of drift has been hypothesized, but never tested. Using a combination of de novo genome sequencing, population genomics, transcriptomics, and proteomics, we compare the two modes of evolution in the pitviper, Protobothrops mucrosquamatus. By partitioning selective constraints and adaptive evolution in a McDonald–Kreitman-type framework, we find support for both hypotheses: venom proteins indeed experience both stronger positive selection, and lower selective constraint than other genes in the genome. Furthermore, the strength of selection may be modulated by expression level, with more abundant proteins experiencing weaker selective constraint, leading to the accumulation of more deleterious mutations. These findings show that snake venoms evolve by a combination of adaptive and neutral mechanisms, both of which explain their extraordinarily high rates of molecular evolution. In addition to positive selection, which optimizes efficacy of the venom in the short term, relaxed selective constraints for deleterious mutations can lead to more rapid turnover of individual proteins, and potentially to exploration of a larger venom phenotypic space.
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Affiliation(s)
- Steven D Aird
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa-ken, Japan
| | - Jigyasa Arora
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa-ken, Japan
| | - Agneesh Barua
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa-ken, Japan
| | - Lijun Qiu
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa-ken, Japan
| | - Kouki Terada
- Okinawa Prefectural Institute of Health and the Environment, Biology and Ecology Group, Nanjo-shi, Okinawa, Japan
| | - Alexander S Mikheyev
- Ecology and Evolution Unit, Okinawa Institute of Science and Technology Graduate University, Kunigami-gun, Okinawa-ken, Japan
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14
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Phuong MA, Mahardika GN. Targeted Sequencing of Venom Genes from Cone Snail Genomes Improves Understanding of Conotoxin Molecular Evolution. Mol Biol Evol 2018; 35:1210-1224. [PMID: 29514313 PMCID: PMC5913681 DOI: 10.1093/molbev/msy034] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To expand our capacity to discover venom sequences from the genomes of venomous organisms, we applied targeted sequencing techniques to selectively recover venom gene superfamilies and nontoxin loci from the genomes of 32 cone snail species (family, Conidae), a diverse group of marine gastropods that capture their prey using a cocktail of neurotoxic peptides (conotoxins). We were able to successfully recover conotoxin gene superfamilies across all species with high confidence (> 100× coverage) and used these data to provide new insights into conotoxin evolution. First, we found that conotoxin gene superfamilies are composed of one to six exons and are typically short in length (mean = ∼85 bp). Second, we expanded our understanding of the following genetic features of conotoxin evolution: 1) positive selection, where exons coding the mature toxin region were often three times more divergent than their adjacent noncoding regions, 2) expression regulation, with comparisons to transcriptome data showing that cone snails only express a fraction of the genes available in their genome (24-63%), and 3) extensive gene turnover, where Conidae species varied from 120 to 859 conotoxin gene copies. Finally, using comparative phylogenetic methods, we found that while diet specificity did not predict patterns of conotoxin evolution, dietary breadth was positively correlated with total conotoxin gene diversity. Overall, the targeted sequencing technique demonstrated here has the potential to radically increase the pace at which venom gene families are sequenced and studied, reshaping our ability to understand the impact of genetic changes on ecologically relevant phenotypes and subsequent diversification.
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Affiliation(s)
- Mark A Phuong
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA
| | - Gusti N Mahardika
- Animal Biomedical and Molecular Biology Laboratory, Faculty of Veterinary Medicine, Udayana University Bali, Denpasar, Bali, Indonesia
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15
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Abstract
Cone snail venoms are considered a treasure trove of bioactive peptides. Despite over 800 species of cone snails being known, each producing over 1000 venom peptides, only about 150 unique venom peptides are structurally and functionally characterized. To overcome the limitations of the traditional low-throughput bio-discovery approaches, multi-omics systems approaches have been introduced to accelerate venom peptide discovery and characterisation. This “venomic” approach is starting to unravel the full complexity of cone snail venoms and to provide new insights into their biology and evolution. The main challenge for venomics is the effective integration of transcriptomics, proteomics, and pharmacological data and the efficient analysis of big datasets. Novel database search tools and visualisation techniques are now being introduced that facilitate data exploration, with ongoing advances in related omics fields being expected to further enhance venomics studies. Despite these challenges and future opportunities, cone snail venomics has already exponentially expanded the number of novel venom peptide sequences identified from the species investigated, although most novel conotoxins remain to be pharmacologically characterised. Therefore, efficient high-throughput peptide production systems and/or banks of miniaturized discovery assays are required to overcome this bottleneck and thus enhance cone snail venom bioprospecting and accelerate the identification of novel drug leads.
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16
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Pekár S, Petráková L, Šedo O, Korenko S, Zdráhal Z. Trophic niche, capture efficiency and venom profiles of six sympatric ant-eating spider species (Araneae: Zodariidae). Mol Ecol 2018; 27:1053-1064. [DOI: 10.1111/mec.14485] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 12/22/2017] [Indexed: 11/28/2022]
Affiliation(s)
- Stano Pekár
- Department of Botany and Zoology; Faculty of Science; Masaryk University; Brno Czech Republic
| | - Lenka Petráková
- Department of Botany and Zoology; Faculty of Science; Masaryk University; Brno Czech Republic
| | - Ondrej Šedo
- Research Group Proteomics, CEITEC - Central European Institute of Technology; Masaryk University; Brno Czech Republic
- National Centre for Biomolecular Research; Faculty of Science; Masaryk University; Brno Czech Republic
| | - Stanislav Korenko
- Department of Agroecology and Biometeorology; Faculty of Agrobiology, Food and Natural Resources; Czech University of Life Sciences; Prague Czech Republic
| | - Zbyněk Zdráhal
- Research Group Proteomics, CEITEC - Central European Institute of Technology; Masaryk University; Brno Czech Republic
- National Centre for Biomolecular Research; Faculty of Science; Masaryk University; Brno Czech Republic
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17
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Verdes A, Simpson D, Holford M. Are Fireworms Venomous? Evidence for the Convergent Evolution of Toxin Homologs in Three Species of Fireworms (Annelida, Amphinomidae). Genome Biol Evol 2018; 10:249-268. [PMID: 29293976 PMCID: PMC5778601 DOI: 10.1093/gbe/evx279] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2017] [Indexed: 12/14/2022] Open
Abstract
Amphinomids, more commonly known as fireworms, are a basal lineage of marine annelids characterized by the presence of defensive dorsal calcareous chaetae, which break off upon contact. It has long been hypothesized that amphinomids are venomous and use the chaetae to inject a toxic substance. However, studies investigating fireworm venom from a morphological or molecular perspective are scarce and no venom gland has been identified to date, nor any toxin characterized at the molecular level. To investigate this question, we analyzed the transcriptomes of three species of fireworms-Eurythoe complanata, Hermodice carunculata, and Paramphinome jeffreysii-following a venomics approach to identify putative venom compounds. Our venomics pipeline involved de novo transcriptome assembly, open reading frame, and signal sequence prediction, followed by three different homology search strategies: BLAST, HMMER sequence, and HMMER domain. Following this pipeline, we identified 34 clusters of orthologous genes, representing 13 known toxin classes that have been repeatedly recruited into animal venoms. Specifically, the three species share a similar toxin profile with C-type lectins, peptidases, metalloproteinases, spider toxins, and CAP proteins found among the most highly expressed toxin homologs. Despite their great diversity, the putative toxins identified are predominantly involved in three major biological processes: hemostasis, inflammatory response, and allergic reactions, all of which are commonly disrupted after fireworm stings. Although the putative fireworm toxins identified here need to be further validated, our results strongly suggest that fireworms are venomous animals that use a complex mixture of toxins for defense against predators.
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Affiliation(s)
- Aida Verdes
- Department of Chemistry, Hunter College Belfer Research Center, and The Graduate Center, Program in Biology, Chemistry and Biochemistry, City University of New York
- Department of Invertebrate Zoology, Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York
- Departamento de Biología (Zoología), Facultad de Ciencias, Universidad Autónoma de Madrid, Spain
| | - Danny Simpson
- Department of Population Health, New York University School of Medicine
| | - Mandë Holford
- Department of Chemistry, Hunter College Belfer Research Center, and The Graduate Center, Program in Biology, Chemistry and Biochemistry, City University of New York
- Department of Invertebrate Zoology, Sackler Institute for Comparative Genomics, American Museum of Natural History, New York, New York
- Department of Biochemistry, Weill Cornell Medical College, Cornell University
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18
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Gao B, Peng C, Yang J, Yi Y, Zhang J, Shi Q. Cone Snails: A Big Store of Conotoxins for Novel Drug Discovery. Toxins (Basel) 2017; 9:E397. [PMID: 29215605 PMCID: PMC5744117 DOI: 10.3390/toxins9120397] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 11/28/2017] [Accepted: 12/04/2017] [Indexed: 12/11/2022] Open
Abstract
Marine drugs have developed rapidly in recent decades. Cone snails, a group of more than 700 species, have always been one of the focuses for new drug discovery. These venomous snails capture prey using a diverse array of unique bioactive neurotoxins, usually named as conotoxins or conopeptides. These conotoxins have proven to be valuable pharmacological probes and potential drugs due to their high specificity and affinity to ion channels, receptors, and transporters in the nervous systems of target prey and humans. Several research groups, including ours, have examined the venom gland of cone snails using a combination of transcriptomic and proteomic sequencing, and revealed the existence of hundreds of conotoxin transcripts and thousands of conopeptides in each Conus species. Over 2000 nucleotide and 8000 peptide sequences of conotoxins have been published, and the number is still increasing quickly. However, more than 98% of these sequences still lack 3D structural and functional information. With the rapid development of genomics and bioinformatics in recent years, functional predictions and investigations on conotoxins are making great progress in promoting the discovery of novel drugs. For example, ω-MVIIA was approved by the U.S. Food and Drug Administration in 2004 to treat chronic pain, and nine more conotoxins are at various stages of preclinical or clinical evaluation. In short, the genus Conus, the big family of cone snails, has become an important genetic resource for conotoxin identification and drug development.
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Affiliation(s)
- Bingmiao Gao
- Hainan Provincial Key Laboratory of Research and Development of Tropical Medicinal Plants, Hainan Medical University, Haikou 571199, China.
| | - Chao Peng
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Jiaan Yang
- Micro Pharmtech, Ltd., Wuhan 430075, China.
| | - Yunhai Yi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Junqing Zhang
- Hainan Provincial Key Laboratory of Research and Development of Tropical Medicinal Plants, Hainan Medical University, Haikou 571199, China.
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
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19
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Li Q, Barghi N, Lu A, Fedosov AE, Bandyopadhyay PK, Lluisma AO, Concepcion GP, Yandell M, Olivera BM, Safavi-Hemami H. Divergence of the Venom Exogene Repertoire in Two Sister Species of Turriconus. Genome Biol Evol 2017; 9:2211-2225. [PMID: 28922871 PMCID: PMC5604253 DOI: 10.1093/gbe/evx157] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2017] [Indexed: 02/07/2023] Open
Abstract
The genus Conus comprises approximately 700 species of venomous marine cone snails that are highly efficient predators of worms, snails, and fish. In evolutionary terms, cone snails are relatively young with the earliest fossil records occurring in the Lower Eocene, 55 Ma. The rapid radiation of cone snail species has been accompanied by remarkably high rates of toxin diversification. To shed light on the molecular mechanisms that accompany speciation, we investigated the toxin repertoire of two sister species, Conus andremenezi and Conus praecellens, that were until recently considered a single variable species. A total of 196 and 250 toxin sequences were identified in the venom gland transcriptomes of C. andremenezi and C. praecellens belonging to 25 and 29 putative toxin gene superfamilies, respectively. Comparative analysis with closely (Conus tribblei and Conus lenavati) and more distantly related species (Conus geographus) suggests that speciation is associated with significant diversification of individual toxin genes (exogenes) whereas the expression pattern of toxin gene superfamilies within lineages remains largely conserved. Thus, changes within individual toxin sequences can serve as a sensitive indicator for recent speciation whereas changes in the expression pattern of gene superfamilies are likely to reflect more dramatic differences in a species' interaction with its prey, predators, and competitors.
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Affiliation(s)
- Qing Li
- Eccles Institute of Human Genetics, University of Utah
| | - Neda Barghi
- Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines
- Institute für Populationsgenetik, Vetmeduni, Vienna, 1210, Austria
| | - Aiping Lu
- School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Alexander E. Fedosov
- A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Science, Moscow, Russia
| | | | - Arturo O. Lluisma
- Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines
- Philippine Genome Center, University of the Philippines, Quezon City, Philippines
| | - Gisela P. Concepcion
- Marine Science Institute, University of the Philippines-Diliman, Quezon City, Philippines
- Philippine Genome Center, University of the Philippines, Quezon City, Philippines
| | - Mark Yandell
- Eccles Institute of Human Genetics, University of Utah
- USTAR Center for Genetic Discovery, University of Utah
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20
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Huang Y, Peng C, Yi Y, Gao B, Shi Q. A Transcriptomic Survey of Ion Channel-Based Conotoxins in the Chinese Tubular Cone Snail (Conus betulinus). Mar Drugs 2017; 15:md15070228. [PMID: 28718820 PMCID: PMC5532670 DOI: 10.3390/md15070228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 07/10/2017] [Accepted: 07/13/2017] [Indexed: 02/06/2023] Open
Abstract
Conotoxins in the venom of cone snails (Conus spp.) are a mixture of active peptides that work as blockers, agonists, antagonists, or inactivators of various ion channels. Recently we reported a high-throughput method to identify 215 conotoxin transcripts from the Chinese tubular cone snail, C. betulinus. Here, based on the previous datasets of four transcriptomes from three venom ducts and one venom bulb, we explored ion channel-based conotoxins and predicted their related ion channel receptors. Homologous analysis was also performed for the most abundant ion channel protein, voltage-gated potassium (Kv; with Kv1.1 as the representative), and the most studied ion channel receptor, nicotinic acetylcholine receptor (nAChR; with α2-nAChR as the representative), in different animals. Our transcriptomic survey demonstrated that ion channel-based conotoxins and related ion channel proteins/receptors transcribe differentially between the venom duct and the venom bulb. In addition, we observed that putative κ-conotoxins were the most common conotoxins with the highest transcription levels in the examined C. betulinus. Furthermore, Kv1.1 and α2-nAChR were conserved in their functional domains of deduced protein sequences, suggesting similar effects of conotoxins via the ion channels in various species, including human beings. In a word, our present work suggests a high-throughput way to develop conotoxins as potential drugs for treatment of ion channel-associated human diseases.
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Affiliation(s)
- Yu Huang
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Chao Peng
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Yunhai Yi
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
| | - Bingmiao Gao
- Hainan Provincial Key Laboratory of Research and Development of Tropical Medicinal Plants, Hainan Medical University, Haikou 571199, China.
| | - Qiong Shi
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, BGI Marine, BGI, Shenzhen 518083, China.
- Laboratory of Aquatic Genomics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
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21
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Franklin JB, Rajesh RP, Vinithkumar NV, Kirubagaran R. Identification of short single disulfide-containing contryphans from the venom of cone snails using de novo mass spectrometry-based sequencing methods. Toxicon 2017; 132:50-54. [PMID: 28400262 DOI: 10.1016/j.toxicon.2017.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/05/2017] [Accepted: 04/06/2017] [Indexed: 12/24/2022]
Affiliation(s)
- Jayaseelan Benjamin Franklin
- Andaman and Nicobar Centre for Ocean Science and Technology, National Institute of Ocean Technology, Ministry of Earth Sciences, Government of India, Dollygunj, Port Blair 744103, India.
| | | | - Nambali Valsalan Vinithkumar
- Andaman and Nicobar Centre for Ocean Science and Technology, National Institute of Ocean Technology, Ministry of Earth Sciences, Government of India, Dollygunj, Port Blair 744103, India
| | - Ramalingam Kirubagaran
- Marine Biotechnology Division, Ocean Science and Technology for Islands, National Institute of Ocean Technology, Ministry of Earth Sciences, Government of India, Pallikaranai, Chennai 600100, India
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22
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Olivera BM, Raghuraman S, Schmidt EW, Safavi-Hemami H. Linking neuroethology to the chemical biology of natural products: interactions between cone snails and their fish prey, a case study. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:717-735. [PMID: 28551870 DOI: 10.1007/s00359-017-1183-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 05/12/2017] [Accepted: 05/13/2017] [Indexed: 11/24/2022]
Abstract
From a biological perspective, a natural product can be defined as a compound evolved by an organism for chemical interactions with another organism including prey, predator, competitor, pathogen, symbiont or host. Natural products hold tremendous potential as drug leads and have been extensively studied by chemists and biochemists in the pharmaceutical industry. However, the biological purpose for which a natural product evolved is rarely addressed. By focusing on a well-studied group of natural products-venom components from predatory marine cone snails-this review provides a rationale for why a better understanding of the evolution, biology and biochemistry of natural products will facilitate both neuroscience and the potential for drug leads. The larger goal is to establish a new sub-discipline in the broader field of neuroethology that we refer to as "Chemical Neuroethology", linking the substantial work carried out by chemists on natural products with accelerating advances in neuroethology.
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Affiliation(s)
| | | | - Eric W Schmidt
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Helena Safavi-Hemami
- Department of Biology, University of Utah, Salt Lake City, UT, 84112, USA. .,Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200, Copenhagen, Denmark.
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23
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The Venom Repertoire of Conus gloriamaris (Chemnitz, 1777), the Glory of the Sea. Mar Drugs 2017; 15:md15050145. [PMID: 28531118 PMCID: PMC5450551 DOI: 10.3390/md15050145] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 05/15/2017] [Accepted: 05/17/2017] [Indexed: 12/15/2022] Open
Abstract
The marine cone snail Conus gloriamaris is an iconic species. For over two centuries, its shell was one of the most prized and valuable natural history objects in the world. Today, cone snails have attracted attention for their remarkable venom components. Many conotoxins are proving valuable as research tools, drug leads, and drugs. In this article, we present the venom gland transcriptome of C. gloriamaris, revealing this species' conotoxin repertoire. More than 100 conotoxin sequences were identified, representing a valuable resource for future drug discovery efforts.
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24
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Marine genomics: News and views. Mar Genomics 2017; 31:1-8. [DOI: 10.1016/j.margen.2016.09.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Revised: 09/08/2016] [Accepted: 09/09/2016] [Indexed: 11/23/2022]
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25
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Baten A, Ngangbam AK, Waters DLE, Benkendorff K. Transcriptome of the Australian Mollusc Dicathais orbita Provides Insights into the Biosynthesis of Indoles and Choline Esters. Mar Drugs 2016; 14:md14070135. [PMID: 27447649 PMCID: PMC4962025 DOI: 10.3390/md14070135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 07/08/2016] [Accepted: 07/12/2016] [Indexed: 12/25/2022] Open
Abstract
Dicathais orbita is a mollusc of the Muricidae family and is well known for the production of the expensive dye Tyrian purple and its brominated precursors that have anticancer properties, in addition to choline esters with muscle-relaxing properties. However, the biosynthetic pathways that produce these secondary metabolites in D. orbita are not known. Illumina HiSeq 2000 transcriptome sequencing of hypobranchial glands, prostate glands, albumen glands, capsule glands, and mantle and foot tissues of D. orbita generated over 201 million high quality reads that were de novo assembled into 219,437 contigs. Annotation with reference to the Nr, Swiss-Prot and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases identified candidate-coding regions in 76,152 of these contigs, with transcripts for many enzymes in various metabolic pathways associated with secondary metabolite biosynthesis represented. This study revealed that D. orbita expresses a number of genes associated with indole, sulfur and histidine metabolism pathways that are relevant to Tyrian purple precursor biosynthesis, and many of which were not found in the fully annotated genomes of three other molluscs in the KEGG database. However, there were no matches to known bromoperoxidase enzymes within the D. orbita transcripts. These transcriptome data provide a significant molecular resource for gastropod research in general and Tyrian purple producing Muricidae in particular.
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Affiliation(s)
- Abdul Baten
- Southern Cross Plant Science, Southern Cross University, Lismore NSW 2480, Australia.
| | - Ajit Kumar Ngangbam
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore NSW 2480, Australia.
| | - Daniel L E Waters
- Southern Cross Plant Science, Southern Cross University, Lismore NSW 2480, Australia.
| | - Kirsten Benkendorff
- Marine Ecology Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore NSW 2480, Australia.
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26
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Phuong MA, Mahardika GN, Alfaro ME. Dietary breadth is positively correlated with venom complexity in cone snails. BMC Genomics 2016; 17:401. [PMID: 27229931 PMCID: PMC4880860 DOI: 10.1186/s12864-016-2755-6] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 05/19/2016] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Although diet is believed to be a major factor underlying the evolution of venom, few comparative studies examine both venom composition and diet across a radiation of venomous species. Cone snails within the family, Conidae, comprise more than 700 species of carnivorous marine snails that capture their prey by using a cocktail of venomous neurotoxins (conotoxins or conopeptides). Venom composition across species has been previously hypothesized to be shaped by (a) prey taxonomic class (i.e., worms, molluscs, or fish) and (b) dietary breadth. We tested these hypotheses under a comparative phylogenetic framework using ecological data from past studies in conjunction with venom duct transcriptomes sequenced from 12 phylogenetically disparate cone snail species, including 10 vermivores (worm-eating), one molluscivore, and one generalist. RESULTS We discovered 2223 unique conotoxin precursor peptides that encoded 1864 unique mature toxins across all species, >90 % of which are new to this study. In addition, we identified two novel gene superfamilies and 16 novel cysteine frameworks. Each species exhibited unique venom profiles, with venom composition and expression patterns among species dominated by a restricted set of gene superfamilies and mature toxins. In contrast with the dominant paradigm for interpreting Conidae venom evolution, prey taxonomic class did not predict venom composition patterns among species. We also found a significant positive relationship between dietary breadth and measures of conotoxin complexity. CONCLUSIONS The poor performance of prey taxonomic class in predicting venom components suggests that cone snails have either evolved species-specific expression patterns likely as a consequence of the rapid evolution of conotoxin genes, or that traditional means of categorizing prey type (i.e., worms, mollusc, or fish) and conotoxins (i.e., by gene superfamily) do not accurately encapsulate evolutionary dynamics between diet and venom composition. We also show that species with more generalized diets tend to have more complex venoms and utilize a greater number of venom genes for prey capture. Whether this increased gene diversity confers an increased capacity for evolutionary change remains to be tested. Overall, our results corroborate the key role of diet in influencing patterns of venom evolution in cone snails and other venomous radiations.
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Affiliation(s)
- Mark A Phuong
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA.
| | - Gusti N Mahardika
- Animal Biomedical and Molecular Biology Laboratory, Faculty of Veterinary Medicine, Udayana University Bali, Jl Sesetan-Markisa 6, Denpasar, Bali, 80225, Indonesia
| | - Michael E Alfaro
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA, 90095, USA
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27
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Verdes A, Anand P, Gorson J, Jannetti S, Kelly P, Leffler A, Simpson D, Ramrattan G, Holford M. From Mollusks to Medicine: A Venomics Approach for the Discovery and Characterization of Therapeutics from Terebridae Peptide Toxins. Toxins (Basel) 2016; 8:117. [PMID: 27104567 PMCID: PMC4848642 DOI: 10.3390/toxins8040117] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 04/06/2016] [Accepted: 04/07/2016] [Indexed: 12/21/2022] Open
Abstract
Animal venoms comprise a diversity of peptide toxins that manipulate molecular targets such as ion channels and receptors, making venom peptides attractive candidates for the development of therapeutics to benefit human health. However, identifying bioactive venom peptides remains a significant challenge. In this review we describe our particular venomics strategy for the discovery, characterization, and optimization of Terebridae venom peptides, teretoxins. Our strategy reflects the scientific path from mollusks to medicine in an integrative sequential approach with the following steps: (1) delimitation of venomous Terebridae lineages through taxonomic and phylogenetic analyses; (2) identification and classification of putative teretoxins through omics methodologies, including genomics, transcriptomics, and proteomics; (3) chemical and recombinant synthesis of promising peptide toxins; (4) structural characterization through experimental and computational methods; (5) determination of teretoxin bioactivity and molecular function through biological assays and computational modeling; (6) optimization of peptide toxin affinity and selectivity to molecular target; and (7) development of strategies for effective delivery of venom peptide therapeutics. While our research focuses on terebrids, the venomics approach outlined here can be applied to the discovery and characterization of peptide toxins from any venomous taxa.
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Affiliation(s)
- Aida Verdes
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- The Graduate Center, City University of New York, 365 5th Ave, New York, NY 10016, USA.
- Sackler Institute for Comparative Genomics, Invertebrate Zoology, American Museum of Natural History, Central Park West & 79th St, New York, NY 10024, USA.
| | - Prachi Anand
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
| | - Juliette Gorson
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- The Graduate Center, City University of New York, 365 5th Ave, New York, NY 10016, USA.
- Sackler Institute for Comparative Genomics, Invertebrate Zoology, American Museum of Natural History, Central Park West & 79th St, New York, NY 10024, USA.
| | - Stephen Jannetti
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- The Graduate Center, City University of New York, 365 5th Ave, New York, NY 10016, USA.
| | - Patrick Kelly
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- The Graduate Center, City University of New York, 365 5th Ave, New York, NY 10016, USA.
| | - Abba Leffler
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- Sackler Institute of Graduate Biomedical Sciences, New York University School of Medicine 550 1st Avenue, New York, NY 10016, USA.
| | - Danny Simpson
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- Tandon School of Engineering, New York University 6 MetroTech Center, Brooklyn, NY 11201, USA.
| | - Girish Ramrattan
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
| | - Mandë Holford
- Hunter College, The City University of New York, Belfer Research Building, 413 E. 69th Street, New York, NY 10021, USA.
- The Graduate Center, City University of New York, 365 5th Ave, New York, NY 10016, USA.
- Sackler Institute for Comparative Genomics, Invertebrate Zoology, American Museum of Natural History, Central Park West & 79th St, New York, NY 10024, USA.
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28
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Peng C, Yao G, Gao BM, Fan CX, Bian C, Wang J, Cao Y, Wen B, Zhu Y, Ruan Z, Zhao X, You X, Bai J, Li J, Lin Z, Zou S, Zhang X, Qiu Y, Chen J, Coon SL, Yang J, Chen JS, Shi Q. High-throughput identification of novel conotoxins from the Chinese tubular cone snail (Conus betulinus) by multi-transcriptome sequencing. Gigascience 2016; 5:17. [PMID: 27087938 PMCID: PMC4832519 DOI: 10.1186/s13742-016-0122-9] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Accepted: 04/07/2016] [Indexed: 01/06/2023] Open
Abstract
Background The venom of predatory marine cone snails mainly contains a diverse array of unique bioactive peptides commonly referred to as conopeptides or conotoxins. These peptides have proven to be valuable pharmacological probes and potential drugs because of their high specificity and affinity to important ion channels, receptors and transporters of the nervous system. Most previous studies have focused specifically on the conopeptides from piscivorous and molluscivorous cone snails, but little attention has been devoted to the dominant vermivorous species. Results The vermivorous Chinese tubular cone snail, Conus betulinus, is the dominant Conus species inhabiting the South China Sea. The transcriptomes of venom ducts and venom bulbs from a variety of specimens of this species were sequenced using both next-generation sequencing and traditional Sanger sequencing technologies, resulting in the identification of a total of 215 distinct conopeptides. Among these, 183 were novel conopeptides, including nine new superfamilies. It appeared that most of the identified conopeptides were synthesized in the venom duct, while a handful of conopeptides were identified only in the venom bulb and at very low levels. Conclusions We identified 215 unique putative conopeptide transcripts from the combination of five transcriptomes and one EST sequencing dataset. Variation in conopeptides from different specimens of C. betulinus was observed, which suggested the presence of intraspecific variability in toxin production at the genetic level. These novel conopeptides provide a potentially fertile resource for the development of new pharmaceuticals, and a pathway for the discovery of new conotoxins. Electronic supplementary material The online version of this article (doi:10.1186/s13742-016-0122-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chao Peng
- BGI-Shenzhen, Shenzhen, 518083 China
| | - Ge Yao
- Research Institute of Pharmaceutical Chemistry, Beijing, 102205 China
| | - Bing-Miao Gao
- School of Pharmaceutical Sciences, Hainan Medical University, Haikou, 571199 China
| | - Chong-Xu Fan
- Research Institute of Pharmaceutical Chemistry, Beijing, 102205 China
| | - Chao Bian
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | | | - Ying Cao
- Research Institute of Pharmaceutical Chemistry, Beijing, 102205 China
| | - Bo Wen
- BGI-Shenzhen, Shenzhen, 518083 China
| | | | - Zhiqiang Ruan
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | | | - Xinxin You
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | - Jie Bai
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | - Jia Li
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | | | | | - Xinhui Zhang
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | - Ying Qiu
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | - Jieming Chen
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China
| | - Steven L Coon
- Molecular Genomics Laboratory, National Institutes of Health, Bethesda, MD 20892 USA
| | - Jiaan Yang
- Micro Pharmatech Ltd, Wuhan, 430075 China
| | - Ji-Sheng Chen
- Research Institute of Pharmaceutical Chemistry, Beijing, 102205 China
| | - Qiong Shi
- BGI-Shenzhen, Shenzhen, 518083 China ; Shenzhen Key Laboratory of Marine Genomics, Guangdong Provincial Key Laboratory of Molecular Breeding in Marine Economic Animals, State Key Laboratory of Agricultural Genomics, Shenzhen, 518083 China ; BGI-Zhenjiang Institute of Hydrobiology, Zhenjiang, 212000 China
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29
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Prashanth JR, Dutertre S, Jin AH, Lavergne V, Hamilton B, Cardoso FC, Griffin J, Venter DJ, Alewood PF, Lewis RJ. The role of defensive ecological interactions in the evolution of conotoxins. Mol Ecol 2016; 25:598-615. [PMID: 26614983 DOI: 10.1111/mec.13504] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 11/23/2015] [Accepted: 11/24/2015] [Indexed: 10/22/2022]
Abstract
Venoms comprise of complex mixtures of peptides evolved for predation and defensive purposes. Remarkably, some carnivorous cone snails can inject two distinct venoms in response to predatory or defensive stimuli, providing a unique opportunity to study separately how different ecological pressures contribute to toxin diversification. Here, we report the extraordinary defensive strategy of the Rhizoconus subgenus of cone snails. The defensive venom from this worm-hunting subgenus is unusually simple, almost exclusively composed of αD-conotoxins instead of the ubiquitous αA-conotoxins found in the more complex defensive venom of mollusc- and fish-hunting cone snails. A similarly compartmentalized venom gland as those observed in the other dietary groups facilitates the deployment of this defensive venom. Transcriptomic analysis of a Conus vexillum venom gland revealed the αD-conotoxins as the major transcripts, with lower amounts of 15 known and four new conotoxin superfamilies also detected with likely roles in prey capture. Our phylogenetic and molecular evolution analysis of the αD-conotoxins from five subgenera of cone snails suggests they evolved episodically as part of a defensive strategy in the Rhizoconus subgenus. Thus, our results demonstrate an important role for defence in the evolution of conotoxins.
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Affiliation(s)
- J R Prashanth
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - S Dutertre
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia.,Institut des Biomolécules Max Mousseron, UMR 5247, Université Montpellier-CNRS, Place Eugène Bataillon, 34095, Montpellier Cedex 5, France
| | - A H Jin
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - V Lavergne
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - B Hamilton
- Pathology, Mater Health Services, Raymond Terrace, South Brisbane, Qld, 4101, Australia.,Mater Research Institute, The University of Queensland, St. Lucia, Qld, 4072, Australia
| | - F C Cardoso
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - J Griffin
- ACRF Microscopy Facility, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - D J Venter
- Pathology, Mater Health Services, Raymond Terrace, South Brisbane, Qld, 4101, Australia.,Mater Research Institute, The University of Queensland, St. Lucia, Qld, 4072, Australia.,School of Medicine, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - P F Alewood
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
| | - R J Lewis
- Centre for Pain Research, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Qld, 4072, Australia
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30
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Barghi N, Concepcion GP, Olivera BM, Lluisma AO. Structural features of conopeptide genes inferred from partial sequences of the Conus tribblei genome. Mol Genet Genomics 2015; 291:411-22. [PMID: 26423067 DOI: 10.1007/s00438-015-1119-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2015] [Accepted: 09/18/2015] [Indexed: 10/23/2022]
Abstract
The evolvability of venom components (in particular, the gene-encoded peptide toxins) in venomous species serves as an adaptive strategy allowing them to target new prey types or respond to changes in the prey field. The structure, organization, and expression of the venom peptide genes may provide insights into the molecular mechanisms that drive the evolution of such genes. Conus is a particularly interesting group given the high chemical diversity of their venom peptides, and the rapid evolution of the conopeptide-encoding genes. Conus genomes, however, are large and characterized by a high proportion of repetitive sequences. As a result, the structure and organization of conopeptide genes have remained poorly known. In this study, a survey of the genome of Conus tribblei was undertaken to address this gap. A partial assembly of C. tribblei genome was generated; the assembly, though consisting of a large number of fragments, accounted for 2160.5 Mb of sequence. A large number of repetitive genomic elements consisting of 642.6 Mb of retrotransposable elements, simple repeats, and novel interspersed repeats were observed. We characterized the structural organization and distribution of conotoxin genes in the genome. A significant number of conopeptide genes (estimated to be between 148 and 193) belonging to different superfamilies with complete or nearly complete exon regions were observed, ~60 % of which were expressed. The unexpressed conopeptide genes represent hidden but significant conotoxin diversity. The conotoxin genes also differed in the frequency and length of the introns. The interruption of exons by long introns in the conopeptide genes and the presence of repeats in the introns may indicate the importance of introns in facilitating recombination, evolution and diversification of conotoxins. These findings advance our understanding of the structural framework that promotes the gene-level molecular evolution of venom peptides.
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Affiliation(s)
- Neda Barghi
- Marine Science Institute, University of the Philippines-Diliman, 1101, Quezon City, Philippines.,Institut für Populationsgenetik, Vetmeduni Vienna, Vienna, Austria
| | - Gisela P Concepcion
- Marine Science Institute, University of the Philippines-Diliman, 1101, Quezon City, Philippines.,Philippine Genome Center, University of the Philippines, 1101, Quezon City, Philippines
| | | | - Arturo O Lluisma
- Marine Science Institute, University of the Philippines-Diliman, 1101, Quezon City, Philippines. .,Philippine Genome Center, University of the Philippines, 1101, Quezon City, Philippines.
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