1
|
Yao G, Peng C, Zhu Y, Fan C, Jiang H, Chen J, Cao Y, Shi Q. High-Throughput Identification and Analysis of Novel Conotoxins from Three Vermivorous Cone Snails by Transcriptome Sequencing. Mar Drugs 2019; 17:md17030193. [PMID: 30917600 PMCID: PMC6471451 DOI: 10.3390/md17030193] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/19/2019] [Accepted: 03/25/2019] [Indexed: 12/13/2022] Open
Abstract
The venom of each Conus species consists of a diverse array of neurophysiologically active peptides, which are mostly unique to the examined species. In this study, we performed high-throughput transcriptome sequencing to extract and analyze putative conotoxin transcripts from the venom ducts of 3 vermivorous cone snails (C. caracteristicus, C. generalis, and C. quercinus), which are resident in offshore waters of the South China Sea. In total, 118, 61, and 48 putative conotoxins (across 22 superfamilies) were identified from the 3 Conus species, respectively; most of them are novel, and some possess new cysteine patterns. Interestingly, a series of 45 unassigned conotoxins presented with a new framework of C-C-C-C-C-C, and their mature regions were sufficiently distinct from any other known conotoxins, most likely representing a new superfamily. O- and M-superfamily conotoxins were the most abundant in transcript number and transcription level, suggesting their critical roles in the venom functions of these vermivorous cone snails. In addition, we identified numerous functional proteins with potential involvement in the biosynthesis, modification, and delivery process of conotoxins, which may shed light on the fundamental mechanisms for the generation of these important conotoxins within the venom duct of cone snails.
Collapse
Affiliation(s)
- Ge Yao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, 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.
| | - Yabing Zhu
- BGI Genomics, BGI-Shenzhen, Shenzhen 518083, China.
| | - Chongxu Fan
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Hui Jiang
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Jisheng Chen
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
| | - Ying Cao
- State Key Laboratory of NBC Protection for Civilian, Beijing 102205, 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.
- Laboratory of Aquatic Genomics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen 518060, China.
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Conotoxin gene superfamilies. Mar Drugs 2014; 12:6058-101. [PMID: 25522317 PMCID: PMC4278219 DOI: 10.3390/md12126058] [Citation(s) in RCA: 130] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 11/29/2014] [Accepted: 12/04/2014] [Indexed: 12/16/2022] Open
Abstract
Conotoxins are the peptidic components of the venoms of marine cone snails (genus Conus). They are remarkably diverse in terms of structure and function. Unique potency and selectivity profiles for a range of neuronal targets have made several conotoxins valuable as research tools, drug leads and even therapeutics, and has resulted in a concerted and increasing drive to identify and characterise new conotoxins. Conotoxins are translated from mRNA as peptide precursors, and cDNA sequencing is now the primary method for identification of new conotoxin sequences. As a result, gene superfamily, a classification based on precursor signal peptide identity, has become the most convenient method of conotoxin classification. Here we review each of the described conotoxin gene superfamilies, with a focus on the structural and functional diversity present in each. This review is intended to serve as a practical guide to conotoxin superfamilies and to facilitate interpretation of the increasing number of conotoxin precursor sequences being identified by targeted-cDNA sequencing and more recently high-throughput transcriptome sequencing.
Collapse
|
4
|
Wu Y, Wang L, Zhou M, Jiang X, Zhu X, Chen Y, Luo S, You Y, Ren Z, Xu A. Soluble expression, purification and functional identification of the framework XV conotoxins derived from different Conus species. Peptides 2014; 56:77-83. [PMID: 24703966 DOI: 10.1016/j.peptides.2014.03.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 03/14/2014] [Accepted: 03/17/2014] [Indexed: 11/15/2022]
Abstract
The conotoxin cysteine framework XV (-C-C-CC-C-C-C-C-), which was named Lt15a, was firstly identified from the cDNA library of Conus litteratus. After that, 18 new framework XV conotoxin sequences were cloned from nine Conus species. Like other conopeptides, the XV-conotoxins have the conserved signal peptide and propeptide, and there are also some conserved residues in their mature peptide. All the framework XV conotoxins were apparently converged into two branches, because of the indel and point mutations occurred in their mature peptides. By fused with thioredoxin and 6×His tag, six XV-conotoxins were successfully expressed in Escherichia coli and purified. Different framework XV conotoxins have distinct biological activities on mice and frogs, and that may be related to the diversity of the toxin sequences. All the six XV-conotoxins had no obvious effects on the sodium currents of DRG neuron cells of Sprague-Dawley (SD) rats. The identification of this framework of conotoxins enriches our understanding of the structural and functional diversity of conotoxin.
Collapse
Affiliation(s)
- Yun Wu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Lei Wang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Maojun Zhou
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Xiuhua Jiang
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Xiaoyan Zhu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Yu Chen
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Shaonan Luo
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Yuwen You
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Zhenghua Ren
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China
| | - Anlong Xu
- State Key Laboratory of Biocontrol, Guangdong Province Key Laboratory of Pharmaceutical Functional Genes, National Engineering Research Center of South China Sea Marine Biotechnology, Department of Biochemistry, College of Life Sciences, Sun Yat-sen University, Guangzhou 510275, People's Republic of China; Beijing University of Chinese Medicine, 11 Dong Shan Huan Road, Beijing 100029, People's Republic of China.
| |
Collapse
|
5
|
Zamora-Bustillos R, Rivera-Reyes R, Aguilar MB, Michel-Morfín E, Landa-Jaime V, Falcón A, Heimer EP. Identification, by RT-PCR, of eight novel I₂-conotoxins from the worm-hunting cone snails Conus brunneus, Conus nux, and Conus princeps from the eastern Pacific (Mexico). Peptides 2014; 53:22-9. [PMID: 24486530 DOI: 10.1016/j.peptides.2014.01.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Revised: 01/12/2014] [Accepted: 01/13/2014] [Indexed: 10/25/2022]
Abstract
Marine snails of the genus Conus (∼500 species) are tropical predators that produce venoms for capturing prey, defense and competitive interactions. These venoms contain 50-200 different peptides ("conotoxins") that generally comprise 7-40 amino acid residues (including 0-5 disulfide bridges), and that frequently contain diverse posttranslational modifications, some of which have been demonstrated to be important for folding, stability, and biological activity. Most conotoxins affect voltage- and ligand-gated ion channels, G protein-coupled receptors, and neurotransmitter transporters, generally with high affinity and specificity. Due to these features, several conotoxins are used as molecular tools, diagnostic agents, medicines, and models for drug design. Based on the signal sequence of their precursors, conotoxins have been classified into genetic superfamilies, whereas their molecular targets allow them to be classified into pharmacological families. The objective of this work was to identify and analyze partial cDNAs encoding precursors of conotoxins belonging to I superfamily from three vermivorous species of the Mexican Pacific coast: C. brunneus, C. nux and C. princeps. The precursors identified contain diverse numbers of amino acid residues (C. brunneus, 65 or 71; C. nux, 70; C. princeps, 72 or 73), and all include a highly conserved signal peptide, a C-terminal propeptide, and a mature toxin. All the latter have one of the typical Cys frameworks of the I-conotoxins (C-C-CC-CC-C-C). The prepropeptides belong to the I2-superfamily, and encode eight different hydrophilic and acidic mature toxins, rather similar among them, and some of which have similarity with I2-conotoxins targeting voltage- and voltage-and-calcium-gated potassium channels.
Collapse
Affiliation(s)
- R Zamora-Bustillos
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro 76230, Mexico; Laboratorio de Genética Molecular, Instituto Tecnológico de Conkal, Conkal, Yucatán 97345, Mexico
| | - R Rivera-Reyes
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro 76230, Mexico
| | - M B Aguilar
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro 76230, Mexico.
| | - E Michel-Morfín
- Departamento de Estudios para el Desarrollo Sustentable de Zonas Costeras. CUCSUR-Universidad de Guadalajara, San Patricio-Melaque, Jalisco 48980, Mexico
| | - V Landa-Jaime
- Departamento de Estudios para el Desarrollo Sustentable de Zonas Costeras. CUCSUR-Universidad de Guadalajara, San Patricio-Melaque, Jalisco 48980, Mexico; Posgrado en Ciencias Biológicas y Agropecuarias, Universidad Autónoma de Nayarit, Mexico
| | - A Falcón
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro 76230, Mexico
| | - E P Heimer
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM Juriquilla, Querétaro 76230, Mexico
| |
Collapse
|
6
|
Robinson SD, Safavi-Hemami H, McIntosh LD, Purcell AW, Norton RS, Papenfuss AT. Diversity of conotoxin gene superfamilies in the venomous snail, Conus victoriae. PLoS One 2014; 9:e87648. [PMID: 24505301 PMCID: PMC3914837 DOI: 10.1371/journal.pone.0087648] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/28/2013] [Indexed: 12/31/2022] Open
Abstract
Animal venoms represent a vast library of bioactive peptides and proteins with proven potential, not only as research tools but also as drug leads and therapeutics. This is illustrated clearly by marine cone snails (genus Conus), whose venoms consist of mixtures of hundreds of peptides (conotoxins) with a diverse array of molecular targets, including voltage- and ligand-gated ion channels, G-protein coupled receptors and neurotransmitter transporters. Several conotoxins have found applications as research tools, with some being used or developed as therapeutics. The primary objective of this study was the large-scale discovery of conotoxin sequences from the venom gland of an Australian cone snail species, Conus victoriae. Using cDNA library normalization, high-throughput 454 sequencing, de novo transcriptome assembly and annotation with BLASTX and profile hidden Markov models, we discovered over 100 unique conotoxin sequences from 20 gene superfamilies, the highest diversity of conotoxins so far reported in a single study. Many of the sequences identified are new members of known conotoxin superfamilies, some help to redefine these superfamilies and others represent altogether new classes of conotoxins. In addition, we have demonstrated an efficient combination of methods to mine an animal venom gland and generate a library of sequences encoding bioactive peptides.
Collapse
Affiliation(s)
- Samuel D. Robinson
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
- * E-mail: (SDR); (HSH)
| | - Helena Safavi-Hemami
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, VIC, Australia
- * E-mail: (SDR); (HSH)
| | - Lachlan D. McIntosh
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia
| | - Anthony W. Purcell
- Department of Biochemistry and Molecular Biology, Bio21 Institute, University of Melbourne, Parkville, VIC, Australia
| | - Raymond S. Norton
- Medicinal Chemistry, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Anthony T. Papenfuss
- Bioinformatics Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Melbourne, VIC, Australia
| |
Collapse
|
7
|
Molecular evolution and diversity of Conus peptide toxins, as revealed by gene structure and intron sequence analyses. PLoS One 2013; 8:e82495. [PMID: 24349297 PMCID: PMC3862624 DOI: 10.1371/journal.pone.0082495] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 10/25/2013] [Indexed: 11/19/2022] Open
Abstract
Cone snails, which are predatory marine gastropods, produce a cocktail of venoms used for predation, defense and competition. The major venom component, conotoxin, has received significant attention because it is useful in neuroscience research, drug development and molecular diversity studies. In this study, we report the genomic characterization of nine conotoxin gene superfamilies from 18 Conus species and investigate the relationships among conotoxin gene structure, molecular evolution and diversity. The I1, I2, M, O2, O3, P, S, and T superfamily precursors all contain three exons and two introns, while A superfamily members contain two exons and one intron. The introns are conserved within a certain gene superfamily, and also conserved across different Conus species, but divergent among different superfamilies. The intronic sequences contain many simple repeat sequences and regulatory elements that may influence conotoxin gene expression. Furthermore, due to the unique gene structure of conotoxins, the base substitution rates and the number of positively selected sites vary greatly among exons. Many more point mutations and trinucleotide indels were observed in the mature peptide exon than in the other exons. In addition, the first example of alternative splicing in conotoxin genes was found. These results suggest that the diversity of conotoxin genes has been shaped by point mutations and indels, as well as rare gene recombination or alternative splicing events, and that the unique gene structures could have made a contribution to the evolution of conotoxin genes.
Collapse
|
8
|
A novel inhibitor of α9α10 nicotinic acetylcholine receptors from Conus vexillum delineates a new conotoxin superfamily. PLoS One 2013; 8:e54648. [PMID: 23382933 PMCID: PMC3559828 DOI: 10.1371/journal.pone.0054648] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 12/13/2012] [Indexed: 11/19/2022] Open
Abstract
Conotoxins (CTxs) selectively target a range of ion channels and receptors, making them widely used tools for probing nervous system function. Conotoxins have been previously grouped into superfamilies according to signal sequence and into families based on their cysteine framework and biological target. Here we describe the cloning and characterization of a new conotoxin, from Conus vexillum, named αB-conotoxin VxXXIVA. The peptide does not belong to any previously described conotoxin superfamily and its arrangement of Cys residues is unique among conopeptides. Moreover, in contrast to previously characterized conopeptide toxins, which are expressed initially as prepropeptide precursors with a signal sequence, a ‘‘pro’’ region, and the toxin-encoding region, the precursor sequence of αB-VxXXIVA lacks a ‘‘pro’’ region. The predicted 40-residue mature peptide, which contains four Cys, was synthesized in each of the three possible disulfide arrangements. Investigation of the mechanism of action of αB-VxXXIVA revealed that the peptide is a nicotinic acetylcholine receptor (nAChR) antagonist with greatest potency against the α9α10 subtype. 1H nuclear magnetic resonance (NMR) spectra indicated that all three αB-VxXXIVA isomers were poorly structured in aqueous solution. This was consistent with circular dichroism (CD) results which showed that the peptides were unstructured in buffer, but adopted partially helical conformations in aqueous trifluoroethanol (TFE) solution. The α9α10 nAChR is an important target for the development of analgesics and cancer chemotherapeutics, and αB-VxXXIVA represents a novel ligand with which to probe the structure and function of this protein.
Collapse
|
9
|
Conotoxins that confer therapeutic possibilities. Mar Drugs 2012; 10:1244-1265. [PMID: 22822370 PMCID: PMC3397437 DOI: 10.3390/md10061244] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/24/2012] [Accepted: 05/24/2012] [Indexed: 12/19/2022] Open
Abstract
Cone snails produce a distinctive repertoire of venom peptides that are used both as a defense mechanism and also to facilitate the immobilization and digestion of prey. These peptides target a wide variety of voltage- and ligand-gated ion channels, which make them an invaluable resource for studying the properties of these ion channels in normal and diseased states, as well as being a collection of compounds of potential pharmacological use in their own right. Examples include the United States Food and Drug Administration (FDA) approved pharmaceutical drug, Ziconotide (Prialt®; Elan Pharmaceuticals, Inc.) that is the synthetic equivalent of the naturally occurring ω-conotoxin MVIIA, whilst several other conotoxins are currently being used as standard research tools and screened as potential therapeutic drugs in pre-clinical or clinical trials. These developments highlight the importance of driving conotoxin-related research. A PubMed query from 1 January 2007 to 31 August 2011 combined with hand-curation of the retrieved articles allowed for the collation of 98 recently identified conotoxins with therapeutic potential which are selectively discussed in this review. Protein sequence similarity analysis tentatively assigned uncharacterized conotoxins to predicted functional classes. Furthermore, conotoxin therapeutic potential for neurodegenerative disorders (NDD) was also inferred.
Collapse
|
10
|
Lluisma AO, Milash BA, Moore B, Olivera BM, Bandyopadhyay PK. Novel venom peptides from the cone snail Conus pulicarius discovered through next-generation sequencing of its venom duct transcriptome. Mar Genomics 2012; 5:43-51. [PMID: 22325721 DOI: 10.1016/j.margen.2011.09.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Revised: 09/09/2011] [Accepted: 09/16/2011] [Indexed: 10/14/2022]
Abstract
The venom peptides (i.e., conotoxins or conopeptides) that species in the genus Conus collectively produce are remarkably diverse, estimated to be around 50,000 to 140,000, but the pace of discovery and characterization of these peptides have been rather slow. To date, only a minor fraction have been identified and studied. However, the advent of next-generation DNA sequencing technologies has opened up opportunities for expediting the exploration of this diversity. The whole transcriptome of a venom duct from the vermivorous marine snail C. pulicarius was sequenced using the 454 sequencing platform. Analysis of the data set resulted in the identification of over eighty unique putative conopeptide sequences, the highest number discovered so far from a Conus venom duct transcriptome. More importantly, majority of the sequences were potentially novel, many with unexpected structural features, hinting at the vastness of the diversity of Conus venom peptides that remains to be explored. The sequences represented at least 14 major superfamilies/types (disulfide- and non-disulfide-rich), indicating the structural and functional diversity of conotoxins in the venom of C. pulicarius. In addition, the contryphans were surprisingly more diverse than what is currently known. Comparative analysis of the O-superfamily sequences also revealed insights into the complexity of the processes that drive the evolution and diversification of conotoxins.
Collapse
Affiliation(s)
- Arturo O Lluisma
- Department of Biology, University of Utah, Salt Lake City, UT 84112, USA
| | | | | | | | | |
Collapse
|
11
|
Blunt JW, Copp BR, Munro MHG, Northcote PT, Prinsep MR. Marine natural products. Nat Prod Rep 2010; 28:196-268. [PMID: 21152619 DOI: 10.1039/c005001f] [Citation(s) in RCA: 343] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- John W Blunt
- Department of Chemistry, University of Canterbury, Christchurch, New Zealand.
| | | | | | | | | |
Collapse
|
12
|
Liu Z, Yu Z, Liu N, Zhao C, Hu J, Dai Q. cDNA cloning of conotoxins with framework XII from several Conus species. Acta Biochim Biophys Sin (Shanghai) 2010; 42:656-61. [PMID: 20732855 DOI: 10.1093/abbs/gmq066] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In our efforts for cloning novel I(2)-superfamily conotoxins using the signal peptide sequence, we identified a novel conotoxin Lt12.4 from Conus litteratus. This gene has a framework XII (-C-C-C-C-CC-C-C-), which is distinct from the cysteine pattern I(2)-superfamily conotoxin (-C-C-CC-CC-C-C-). Subsequently, we found the signal peptide sequence of Lt12.4 by 5'-RACE. Using this new sequence, we identified another five novel conotoxins with this cysteine pattern from four Conus species (Conus eburneus, Conus imperialis, Conus marmoreus, and C. litteratus). These novel conotoxins have the same cysteine pattern as the reported Gla-TxX and Gla-MII, and may contain Gla residues. Furthermore, they have the highly conserved signal peptide and hypervariable mature peptide sequences, and widely exist in Conus species. Therefore, it could be defined as a new superfamily of E-conotoxins.
Collapse
Affiliation(s)
- Zhuguo Liu
- Beijing Institute of Biotechnology, China
| | | | | | | | | | | |
Collapse
|
13
|
Kaas Q, Westermann JC, Craik DJ. Conopeptide characterization and classifications: an analysis using ConoServer. Toxicon 2010; 55:1491-509. [PMID: 20211197 DOI: 10.1016/j.toxicon.2010.03.002] [Citation(s) in RCA: 160] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 02/25/2010] [Accepted: 03/01/2010] [Indexed: 10/19/2022]
Abstract
Cone snails are carnivorous marine gastropods that have evolved potent venoms to capture their prey. These venoms comprise a rich and diverse cocktail of peptide toxins, or conopeptides, whose high diversity has arisen from an efficient hypermutation mechanism, combined with a high frequency of post-translational modifications. Conopeptides bind with high specificity to distinct membrane receptors, ion channels, and transporters of the central and muscular nervous system. As well as serving their natural function in prey capture, conopeptides have been utilized as versatile tools in neuroscience and have proven valuable as drug leads that target the nervous system in humans. This paper examines current knowledge on conopeptide sequences based on an analysis of gene and peptide sequences in ConoServer (http://www.conoserver.org), a specialized database of conopeptide sequences and three-dimensional structures. We describe updates to the content and organization of ConoServer and discuss correlations between gene superfamilies, cysteine frameworks, pharmacological families targeted by conopeptides, and the phylogeny, habitat, and diet of cone snails. The study identifies gaps in current knowledge of conopeptides and points to potential directions for future research.
Collapse
Affiliation(s)
- Quentin Kaas
- The University of Queensland, Institute for Molecular Bioscience, Division of Chemistry and Structural Biology, Brisbane, 4072 QLD, Australia
| | | | | |
Collapse
|
14
|
Zamora-Bustillos R, Aguilar MB, Falcón A. Identification, by molecular cloning, of a novel type of I2-superfamily conotoxin precursor and two novel I2-conotoxins from the worm-hunter snail Conus spurius from the Gulf of México. Peptides 2010; 31:384-93. [PMID: 19836429 DOI: 10.1016/j.peptides.2009.10.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2009] [Revised: 10/03/2009] [Accepted: 10/06/2009] [Indexed: 11/24/2022]
Abstract
cDNA was prepared from the venom duct of a single Conus spurius specimen collected near the coast of Campeche, México. From it, PCR products were generated aiming to clone I-conotoxin precursors. Thirty clones were sequenced and predicted to encode ten distinct precursors: seven of I(2)-conotoxins and three of I(2)-like-conotoxins. These precursors contain three different, mature toxins, sr11a, sr11b and sr11c, of which two are novel and one (sr11a) has been previously purified and characterized from the venom of this species. The precursors include a 26- (I(2)) or 23- residue signal peptide (I(2)-like), a 31-residue "pro" region (I(2)-like), and a 32-residue mature toxin region (I(2) and I(2)-like). In addition, all the precursors have a 13-residue "post" region which contains a gamma-carboxylation recognition sequence that directs the gamma-carboxylation of Glu-9 and Glu-10 of toxin sr11a and, possibly, Glu-13 of toxin sr11b and Glu-9 of toxin sr11c. This is the first time that a "post" region has been found in precursors of I-conotoxins that also contain a "pro" region. The "post" peptide is enzymatically processed to yield the amidated mature toxin sr11a, which implies that gamma-carboxylation occurs before amidation. Phylogenetic analysis at the whole precursor level indicates that the I(2)-like-conotoxins of C. spurius are more related to I(2)-conotoxins than to I(1)- and I(3)-conotoxins from other species, and that they might represent a new subgroup of the I(2)-superfamily. The three I-conotoxins from C. spurius have charge differences at seven to nine positions, suggesting that they might have different molecular target types or subtypes.
Collapse
Affiliation(s)
- Roberto Zamora-Bustillos
- Laboratorio de Neurofarmacología Marina, Departamento de Neurobiología Celular y Molecular, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus Juriquilla, Querétaro 76230, Mexico
| | | | | |
Collapse
|
15
|
Liu Z, Xu N, Hu J, Zhao C, Yu Z, Dai Q. Identification of novel I-superfamily conopeptides from several clades of Conus species found in the South China Sea. Peptides 2009; 30:1782-7. [PMID: 19595726 DOI: 10.1016/j.peptides.2009.06.036] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/26/2009] [Accepted: 06/26/2009] [Indexed: 11/20/2022]
Abstract
The I-superfamily of Conus peptides represents a new class of peptides with four disulfide bridges (-C-C-CC-CC-C-C-) that falls into three (I1, I2 and I3) categories according to the different signal peptide sequences. The I-superfamily has received increasing attention because it targets K+ ion channels, a function that is relatively rare in conotoxins. Herein we report 11 novel I-superfamily conotoxins from the venom ducts of five Cone snails (Conus eburneus, Conus imperialis, Conus vitulinus, Conus emaciatus and Conus litteratus) native to the South China Sea using a primer designed according to the N-terminus of the signal sequence of I2-superfamily conotoxins. The alignment of sequences revealed that signal regions exhibited moderate conservation with the exception of Eb11.3 from C. eburneus with homologies of 21.1%, 38.5% and 30.0% to the signal peptides of I1, I2 and I3 superfamily conotoxins, respectively. The mature peptides ranged from almost identical to highly divergent between species. Analyses of the evolutionary trees of these peptides with those of reported I-superfamily conotoxins showed that nine of them fall in I2 superfamily clades, but two of them were neither I1- and I2- nor I3-superfamily clades. Notably, some peptides exhibited significantly different amino acid residues in the intercysteine loops compared with group A, B and C of I-superfamily conopeptides, suggesting that they may have different bioactivities and functions.
Collapse
Affiliation(s)
- Zhuguo Liu
- Beijing Institute of Biotechnology, Beijing 100071, People's Republic of China
| | | | | | | | | | | |
Collapse
|