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Walker AA, Chin YKY, Guo S, Jin J, Wilbrink E, Goudarzi MH, Wirth H, Gordon E, Weirauch C, King GF. Structure and bioactivity of an insecticidal trans-defensin from assassin bug venom. Structure 2024; 32:1348-1357.e4. [PMID: 38889720 DOI: 10.1016/j.str.2024.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/30/2024] [Accepted: 05/22/2024] [Indexed: 06/20/2024]
Abstract
Disulfide-rich peptides such as defensins play diverse roles in immunity and ion channel modulation, as well as constituting the bioactive components of many animal venoms. We investigated the structure and bioactivity of U-RDTX-Pp19, a peptide previously discovered in venom of the assassin bug Pristhesancus plagipennis. Recombinant Pp19 (rPp19) was found to possess insecticidal activity when injected into Drosophila melanogaster. A bioinformatic search revealed that domains homologous to Pp19 are produced by assassin bugs and diverse other arthropods. rPp19 co-eluted with native Pp19 isolated from P. plagipennis, which we found is more abundant in hemolymph than venom. We solved the three-dimensional structure of rPp19 using 2D 1H NMR spectroscopy, finding that it adopts a disulfide-stabilized structure highly similar to known trans-defensins, with the same cystine connectivity as human α-defensin (I-VI, II-IV, and III-V). The structure of Pp19 is unique among reported structures of arthropod peptides.
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Affiliation(s)
- Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; Centre of Excellence for Innovations in Protein and Peptide Science, St Lucia, QLD 4072, Australia.
| | - Yanni K-Y Chin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Shaodong Guo
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Jiayi Jin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia
| | - Evienne Wilbrink
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; Fontys University of Applied Sciences, Eindhoven 5612 AR, the Netherlands
| | - Mohaddeseh Hedayati Goudarzi
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; Centre of Excellence for Innovations in Protein and Peptide Science, St Lucia, QLD 4072, Australia
| | - Hayden Wirth
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; Centre of Excellence for Innovations in Protein and Peptide Science, St Lucia, QLD 4072, Australia
| | - Eric Gordon
- Department of Entomology, University of California Riverside, Riverside, CA 92521, USA
| | - Christiane Weirauch
- Department of Entomology, University of California Riverside, Riverside, CA 92521, USA
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia; Centre of Excellence for Innovations in Protein and Peptide Science, St Lucia, QLD 4072, Australia.
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Yamashita T, Rhoads DD, Pummill J. A robust genome assembly with transcriptomic data from the striped bark scorpion, Centruroides vittatus. G3 (BETHESDA, MD.) 2024; 14:jkae120. [PMID: 38885085 PMCID: PMC11304958 DOI: 10.1093/g3journal/jkae120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Accepted: 05/21/2024] [Indexed: 06/20/2024]
Abstract
Scorpions, a seemingly primitive, stinging arthropod taxa, are known to exhibit marked diversity in their venom components. These venoms are known for their human pathology, but they are also important as models for therapeutic and drug development applications. In this study, we report a high-quality genome assembly and annotation of the striped bark scorpion, Centruroides vittatus, created with several shotgun libraries. The final assembly is 760 Mb in size, with a BUSCO score of 97.8%, a 30.85% GC, and an N50 of 2.35 Mb. We estimated 36,189 proteins with 37.32% assigned to Gene Ontology (GO) terms in our GO annotation analysis. We mapped venom toxin genes to 18 contigs and 2 scaffolds. We were also able to identify expression differences between venom gland (telson) and body tissue (carapace) with 19 sodium toxin and 14 potassium toxin genes to 18 contigs and 2 scaffolds. This assembly, along with our transcriptomic data, provides further data to investigate scorpion venom genomics.
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Affiliation(s)
- Tsunemi Yamashita
- Department of Biological Sciences, Arkansas Tech University, Russellville, AR 72801, USA
| | - Douglas D Rhoads
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
| | - Jeff Pummill
- High Performance Computing Center, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
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3
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Díaz C, Lomonte B, Chang-Castillo A, Bonilla F, Alfaro-Chinchilla A, Triana F, Angulo D, Fernández J, Sasa M. Venomics of Scorpion Ananteris platnicki (Lourenço, 1993), a New World Buthid That Inhabits Costa Rica and Panama. Toxins (Basel) 2024; 16:327. [PMID: 39195737 PMCID: PMC11360313 DOI: 10.3390/toxins16080327] [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: 06/18/2024] [Revised: 07/12/2024] [Accepted: 07/18/2024] [Indexed: 08/29/2024] Open
Abstract
Ananteris is a scorpion genus that inhabits dry and seasonal areas of South and Central America. It is located in a distinctive morpho-group of Buthids, the 'Ananteris group', which also includes species distributed in the Old World. Because of the lack of information on venom composition, the study of Ananteris species could have biological and medical relevance. We conducted a venomics analysis of Ananteris platnicki, a tiny scorpion that inhabits Panama and Costa Rica, which shows the presence of putative toxins targeting ion channels, as well as proteins with similarity to hyaluronidases, proteinases, phospholipases A2, members of the CAP-domain family, and hemocyanins, among others. Venom proteolytic and hyaluronidase activities were corroborated. The determination of the primary sequences carried out by mass spectrometry evidences that several peptides are similar to the toxins present in venoms from Old World scorpion genera such as Mesobuthus, Lychas, and Isometrus, but others present in Tityus and Centruroides toxins. Even when this venom displays the characteristic protein families found in all Buthids, with a predominance of putative Na+-channel toxins and proteinases, some identified partial sequences are not common in venoms of the New World species, suggesting its differentiation into a distinctive group separated from other Buthids.
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Affiliation(s)
- Cecilia Díaz
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
- Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José 11501-2060, Costa Rica
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Arturo Chang-Castillo
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Fabián Bonilla
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Adriana Alfaro-Chinchilla
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Felipe Triana
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Diego Angulo
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Julián Fernández
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José 11501-2060, Costa Rica; (B.L.); (A.C.-C.); (F.B.); (A.A.-C.); (F.T.); (D.A.); (J.F.); (M.S.)
- Museo de Zoología, Centro de investigación de Biodiversidad y Ecología Tropical, Universidad de Costa Rica, San José 11501-2060, Costa Rica
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Labropoulou V, Wang L, Magkrioti C, Smagghe G, Swevers L. Single domain von Willebrand factor type C "cytokines" and the regulation of the stress/immune response in insects. ARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY 2024; 115:e22071. [PMID: 38288483 DOI: 10.1002/arch.22071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 10/25/2023] [Accepted: 11/01/2023] [Indexed: 02/01/2024]
Abstract
The single domain von Willebrand factor type C (SVWC) appears in small secreted peptides that are arthropod-specific and are produced following environmental stress or pathogen exposure. Most research has focused on proteins with SVWC domain that are induced after virus infection and are hypothesized to function as "cytokines" to regulate the innate immune response. The expansion of SVWC genes in insect species indicates that many other functions remain to be discovered. Research in shrimp has elucidated the adaptability of Vago-like peptides in the innate immune response against bacteria, fungi and viruses after activation by Jak-STAT and/or Toll/Imd pathways in which they can act as pathogen-recognition receptors or cytokine-like signaling molecules. SVWC factors also appear in scorpion venoms and tick saliva, underlining their versatility to acquire new functions. This review discusses the discovery and function of SVWC peptides from insects to crustaceans and chelicerates and reveals the enormous gaps in knowledge that remain to be filled to understand this enigmatic group of secreted peptides.
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Affiliation(s)
- Vassiliki Labropoulou
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, Athens, Greece
| | - Luoluo Wang
- Red Imported Fire Ant Research Center, South China Agricultural University, Guangzhou, China
| | - Christiana Magkrioti
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, Athens, Greece
| | - Guy Smagghe
- Department of Biology, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- Institute of Entomology, Guizhou University, Guizhou, China
- Department of Plants and Crops, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium
| | - Luc Swevers
- Insect Molecular Genetics and Biotechnology, Institute of Biosciences & Applications, Athens, Greece
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5
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Santibáñez-López CE, Ojanguren-Affilastro AA, Graham MR, Sharma PP. Congruence between ultraconserved element-based matrices and phylotranscriptomic datasets in the scorpion Tree of Life. Cladistics 2023; 39:533-547. [PMID: 37401727 DOI: 10.1111/cla.12551] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2023] [Indexed: 07/05/2023] Open
Abstract
Scorpions are ancient and historically renowned for their potent venom. Traditionally, the systematics of this group of arthropods was supported by morphological characters, until recent phylogenomic analyses (using RNAseq data) revealed most of the higher-level taxa to be non-monophyletic. While these phylogenomic hypotheses are stable for almost all lineages, some nodes have been hard to resolve due to minimal taxonomic sampling (e.g. family Chactidae). In the same line, it has been shown that some nodes in the Arachnid Tree of Life show disagreement between hypotheses generated using transcritptomes and other genomic sources such as the ultraconserved elements (UCEs). Here, we compared the phylogenetic signal of transcriptomes vs. UCEs by retrieving UCEs from new and previously published scorpion transcriptomes and genomes, and reconstructed phylogenies using both datasets independently. We reexamined the monophyly and phylogenetic placement of Chactidae, sampling an additional chactid species using both datasets. Our results showed that both sets of genome-scale datasets recovered highly similar topologies, with Chactidae rendered paraphyletic owing to the placement of Nullibrotheas allenii. As a first step toward redressing the systematics of Chactidae, we establish the family Anuroctonidae (new family) to accommodate the genus Anuroctonus.
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Affiliation(s)
| | | | - Matthew R Graham
- Department of Biology, Eastern Connecticut State University, Willimantic, CT, 06226, USA
| | - Prashant P Sharma
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, 53706, USA
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Nystrom GS, Ellsworth SA, Ward MJ, Rokyta DR. Varying Modes of Selection Among Toxin Families in the Venoms of the Giant Desert Hairy Scorpions (Hadrurus). J Mol Evol 2023; 91:935-962. [PMID: 38091038 DOI: 10.1007/s00239-023-10148-7] [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: 06/19/2023] [Accepted: 11/12/2023] [Indexed: 12/21/2023]
Abstract
Venoms are primarily believed to evolve under strong diversifying selection resulting from persistent coevolution between predator and prey. Recent research has challenged this hypothesis, proposing that venoms from younger venomous lineages (e.g., snakes and cone snails) are governed predominantly by diversifying selection, while venoms from older venomous lineages (e.g., centipedes, scorpions, and spiders) are under stronger purifying selection. However, most research in older lineages has tested selection at more diverse phylogenetic scales. Although these tests are important for evaluating broad macroevolutionary trends underlying venom evolution, they are less equipped to detect species-level evolutionary trends, which likely have large impacts on venom variation seen at more diverse phylogenetic scales. To test for selection among closely related species from an older venomous lineage, we generated high-throughput venom-gland transcriptomes and venom proteomes for four populations of Giant Desert Hairy Scorpions (Hadrurus), including three Hadrurus arizonensis populations and one Hadrurus spadix population. We detected significant episodic and pervasive diversifying selection across a highly abundant toxin family that likely has a major role in venom function ([Formula: see text]KTxs), providing a contrast to the stronger purifying selection identified from other studies on scorpion venoms. Conversely, we detected weak episodic diversifying and/or stronger purifying selection in four toxin families (non-disulfide bridged peptides, phospholipase A2s, scorpine-like antimicrobial peptides, and serine proteases), most of which were less abundant and likely have ancillary functional roles. Finally, although we detected several major toxin families at disproportionate transcriptomic and/or proteomic abundances, we did not identify significant sex-based variation in Hadrurus venoms.
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Affiliation(s)
- Gunnar S Nystrom
- Department of Biological Science, Florida State University, 319 Stadium Dr., Tallahassee, FL, 32306-4295, USA
| | - Schyler A Ellsworth
- Department of Biological Science, Florida State University, 319 Stadium Dr., Tallahassee, FL, 32306-4295, USA
| | - Micaiah J Ward
- Department of Biological Science, Florida State University, 319 Stadium Dr., Tallahassee, FL, 32306-4295, USA
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, 319 Stadium Dr., Tallahassee, FL, 32306-4295, USA.
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Sonoda GG, Tobaruela EDC, Norenburg J, Fabi JP, Andrade SCS. Venomous Noodles: The Evolution of Toxins in Nemertea through Positive Selection and Gene Duplication. Toxins (Basel) 2023; 15:650. [PMID: 37999513 PMCID: PMC10674772 DOI: 10.3390/toxins15110650] [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: 08/30/2023] [Revised: 10/03/2023] [Accepted: 10/11/2023] [Indexed: 11/25/2023] Open
Abstract
Some, probably most and perhaps all, members of the phylum Nemertea are poisonous, documented so far from marine and benthic specimens. Although the toxicity of these animals has been long known, systematic studies on the characterization of toxins, mechanisms of toxicity, and toxin evolution for this group are scarce. Here, we present the first investigation of the molecular evolution of toxins in Nemertea. Using a proteo-transcriptomic approach, we described toxins in the body and poisonous mucus of the pilidiophoran Lineus sanguineus and the hoplonemertean Nemertopsis pamelaroeae. Using these new and publicly available transcriptomes, we investigated the molecular evolution of six selected toxin gene families. In addition, we also characterized in silico the toxin genes found in the interstitial hoplonemertean, Ototyphlonemertes erneba, a meiofaunal taxa. We successfully identified over 200 toxin transcripts in each of these species. Evidence of positive selection and gene duplication was observed in all investigated toxin genes. We hypothesized that the increased rates of gene duplications observed for Pilidiophora could be involved with the expansion of toxin genes. Studies concerning the natural history of Nemertea are still needed to understand the evolution of their toxins. Nevertheless, our results show evolutionary mechanisms similar to other venomous groups.
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Affiliation(s)
- Gabriel Gonzalez Sonoda
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo 05508-090, Brazil;
- Instituto Butantan, São Paulo 05503-900, Brazil
| | - Eric de Castro Tobaruela
- Faculdade de Ciências Farmacêuticas, Food Research Center (FoRC), Universidade de São Paulo, São Paulo 05508-080, Brazil; (E.d.C.T.); (J.P.F.)
| | | | - João Paulo Fabi
- Faculdade de Ciências Farmacêuticas, Food Research Center (FoRC), Universidade de São Paulo, São Paulo 05508-080, Brazil; (E.d.C.T.); (J.P.F.)
| | - Sónia C. S. Andrade
- Departamento de Genética e Biologia Evolutiva, IB-Universidade de São Paulo, São Paulo 05508-090, Brazil;
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Yamashita T, Rhoads DD, Pummill J. A robust genome and assembly with transcriptomic data from the striped scorpion, Centruroides vittatus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.04.551372. [PMID: 37609349 PMCID: PMC10441356 DOI: 10.1101/2023.08.04.551372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
AbstractScorpions, a seemingly primitive, stinging arthropod taxa, are known to exhibit marked diversity in their venom components. These venoms are known for their human pathology, but also important as models for therapeutic and drug development applications. We report a high quality genome assembly and annotation of the striped bark scorpion,Centruroides vittatus, created with several shotgun libraries. The final assembly is 760 Mb in size, with a BUSCO score of 97.8%, a 30.85% GC, and a N50 of 2.35 Mb. We estimated 36,189 proteins with 37.32% assigned to GO terms in our GOanna analysis. We were able to map 2011 and 60 venom toxin genes to contigs and scaffolds, respectively. We were also able to identify expression differences between venom gland (telson) and body tissue (carapace) with 19 Sodium toxin and 14 Potassium toxin genes to 18 contigs and two scaffolds. This assembly along with our transcriptomic data, provides further data to investigate scorpion venom genomics.
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Affiliation(s)
- Tsunemi Yamashita
- Department of Biological Sciences, Arkansas Tech University, Russellville, AR 72801, USA
| | - Douglas D. Rhoads
- Department of Biological Sciences, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
| | - Jeff Pummill
- High Performance Computing Center, University of Arkansas-Fayetteville, Fayetteville, AR 72701, USA
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Çevik YN. A Fast Method for Detection of Fake Venoms and Investigation of Interspecies Variation Using Venoms of Androctonus, Buthus, and Leiurus (Scorpiones: Buthidae) Species. IRANIAN JOURNAL OF PUBLIC HEALTH 2023; 52:1701-1710. [PMID: 37744546 PMCID: PMC10512148 DOI: 10.18502/ijph.v52i8.13408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 05/05/2023] [Indexed: 09/26/2023]
Abstract
Background Within the scorpion family Buthidae, some of the most dangerous venomous genera are Androctonus (A), Buthus (B), and Leiurus (L). This venom is valuable raw material for numerous therapeutic formulations because of its pharmacological potential; however, because of its high prices in the global market, fake "venom mixes" are being made to market illegally, and it is important that these unknown mixes be evaluated. A fast and accurate response to the request for this identification is necessary. Method This study was conducted in Turkey in 2022. Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) is a linear positive-ionization mode was used for identification of scorpion species. The mass spectra of the three scorpion venoms were examined in detail. The peptide and protein profiles in the venoms of congenerous three scorpion venoms and the proportional differences in these venoms were investigated. For interspecific variation, a principal component analysis of all venoms was conducted, and variance values and distance-proximity indices were determined. Results The top three peptide masses in the highest relative abundance for A. australis, B. mardochei, and L. quinquestriatus quinquestriatus, respectively, were 6901, 7431, and 7447; 4238, 5283, and 4055; and 3828, 7868, and 6799 Da. While the variance rate between A. australis and the other two venoms was 40%, this rate was 38% between B. mordochei and L. quinquestriatus quinquestriatus venoms. Conclusion A very simple protocol of species identification using scorpion venom samples was created using recent advances in MALDI-TOF MS.
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Affiliation(s)
- Yasemin Numanoğlu Çevik
- Microbiology Reference Laboratory and Biological Products Department, Ministry of Health, General Directorate of Public Health, Ankara, Turkey
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Monastyrnaya MM, Kalina RS, Kozlovskaya EP. The Sea Anemone Neurotoxins Modulating Sodium Channels: An Insight at Structure and Functional Activity after Four Decades of Investigation. Toxins (Basel) 2022; 15:8. [PMID: 36668828 PMCID: PMC9863223 DOI: 10.3390/toxins15010008] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 12/13/2022] [Accepted: 12/15/2022] [Indexed: 12/24/2022] Open
Abstract
Many human cardiovascular and neurological disorders (such as ischemia, epileptic seizures, traumatic brain injury, neuropathic pain, etc.) are associated with the abnormal functional activity of voltage-gated sodium channels (VGSCs/NaVs). Many natural toxins, including the sea anemone toxins (called neurotoxins), are an indispensable and promising tool in pharmacological researches. They have widely been carried out over the past three decades, in particular, in establishing different NaV subtypes functional properties and a specific role in various pathologies. Therefore, a large number of publications are currently dedicated to the search and study of the structure-functional relationships of new sea anemone natural neurotoxins-potential pharmacologically active compounds that specifically interact with various subtypes of voltage gated sodium channels as drug discovery targets. This review presents and summarizes some updated data on the structure-functional relationships of known sea anemone neurotoxins belonging to four structural types. The review also emphasizes the study of type 2 neurotoxins, produced by the tropical sea anemone Heteractis crispa, five structurally homologous and one unique double-stranded peptide that, due to the absence of a functionally significant Arg14 residue, loses toxicity but retains the ability to modulate several VGSCs subtypes.
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11
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Venomics of the Scorpion Tityus ocelote (Scorpiones, Buthidae): Understanding Venom Evolution in the Subgenus Archaeotityus. Int J Pept Res Ther 2022. [DOI: 10.1007/s10989-022-10476-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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12
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Explanation of Structure and Function of kv1.3 Potent Blocker From Mesobuthus eupeus Venom Gland: A New Promise in Drug Development. Jundishapur J Nat Pharm Prod 2022. [DOI: 10.5812/jjnpp.120271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Scorpions and other venomous animals are sought with great concern because venom is a source of novel peptides with exciting features. Some toxins of scorpion venom are effectors of potassium channels. Previous studies strongly support the importance of potassium channel toxins for use as pharmacological tools or potential drugs. Objectives: Here, a three-dimensional (3-D) structure and function of a potent acidic blocker of the human voltage-gated potassium ion channel, Kv1.3, previously identified in the scorpion Mesobuthus eupeus venom gland, were interpreted. Methods: The 3-D structure of meuK2-2 was generated using homology modeling. The interaction of meuK2-2 with the Kv1.3 channel was evaluated using a computational protocol employing peptide-protein docking experiments, pose clustering, and 100 ns molecular dynamic simulations to make the 3-D models of the meuK2-2/Kv1.3 complex trustworthy. Results: A CSα/β (cysteine-stabilized α-helical and β-sheet) fold was found for the 3-D structure of meuK2-2. In a different mechanism from what was identified so far, meuK2-2 binds to both turret and pore loop of Kv1.3 through two key residues (Ala28 and Ser11) and H-bonds. The binding of meuK2-2 induces some conformational changes to Kv1.3. Eventually, the side chain of a positively charged amino acid (His9) occupies the channel's pore. All together blocks the ion permeation pathway. Conclusions: MeuK2-2 could block Kv1.3 by a new mechanism. So, it could be a unique target for further investigations to develop a pharmacological tool and potential drug.
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Trim CM, Byrne LJ, Trim SA. Utilisation of compounds from venoms in drug discovery. PROGRESS IN MEDICINAL CHEMISTRY 2021; 60:1-66. [PMID: 34147202 DOI: 10.1016/bs.pmch.2021.01.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Difficult drug targets are becoming the normal course of business in drug discovery, sometimes due to large interacting surfaces or only small differences in selectivity regions. For these, a different approach is merited: compounds lying somewhere between the small molecule and the large antibody in terms of many properties including stability, biodistribution and pharmacokinetics. Venoms have evolved over millions of years to be complex mixtures of stable molecules derived from other somatic molecules, the stability comes from the pressure to be ready for delivery at a moment's notice. Snakes, spiders, scorpions, jellyfish, wasps, fish and even mammals have evolved independent venom systems with complex mixtures in their chemical arsenal. These venom-derived molecules have been proven to be useful tools, such as for the development of antihypotensive angiotensin converting enzyme (ACE) inhibitors and have also made successful drugs such as Byetta® (Exenatide), Integrilin® (Eptifibatide) and Echistatin. Only a small percentage of the available chemical space from venoms has been investigated so far and this is growing. In a new era of biological therapeutics, venom peptides present opportunities for larger target engagement surface with greater stability than antibodies or human peptides. There are challenges for oral absorption and target engagement, but there are venom structures that overcome these and thus provide substrate for engineering novel molecules that combine all desired properties. Venom researchers are characterising new venoms, species, and functions all the time, these provide great substrate for solving the challenges presented by today's difficult targets.
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Affiliation(s)
- Carol M Trim
- Faculty of Science, Engineering and Social Sciences, Natural and Applied Sciences, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, Kent, United Kingdom
| | - Lee J Byrne
- Faculty of Science, Engineering and Social Sciences, Natural and Applied Sciences, School of Psychology and Life Sciences, Canterbury Christ Church University, Canterbury, Kent, United Kingdom
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14
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The evolutionary dynamics of venom toxins made by insects and other animals. Biochem Soc Trans 2021; 48:1353-1365. [PMID: 32756910 DOI: 10.1042/bst20190820] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/11/2020] [Accepted: 07/14/2020] [Indexed: 12/15/2022]
Abstract
Animal venoms are recognised as unique biological systems in which to study molecular evolution. Venom use has evolved numerous times among the insects, and insects today use venom to capture prey, defend themselves from predators, or to subdue and modulate host responses during parasitism. However, little is known about most insect venom toxins or the mode and tempo by which they evolve. Here, I review the evolutionary dynamics of insect venom toxins, and argue that insects offer many opportunities to examine novel aspects of toxin evolution. The key questions addressed are: How do venomous animals evolve from non-venomous animals, and how does this path effect the composition and pharmacology of the venom? What genetic processes (gene duplication, co-option, neofunctionalisation) are most important in toxin evolution? What kinds of selection pressures are acting on toxin-encoding genes and their cognate targets in envenomated animals? The emerging evidence highlights that venom composition and pharmacology adapts quickly in response to changing selection pressures resulting from new ecological interactions, and that such evolution occurs through a stunning variety of genetic mechanisms. Insects offer many opportunities to investigate the evolutionary dynamics of venom toxins due to their evolutionary history rich in venom-related adaptations, and their quick generation time and suitability for culture in the laboratory.
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15
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Daoudi K, Malosse C, Lafnoune A, Darkaoui B, Chakir S, Sabatier JM, Chamot-Rooke J, Cadi R, Oukkache N. Mass spectrometry-based top-down and bottom-up approaches for proteomic analysis of the Moroccan Buthus occitanus scorpion venom. FEBS Open Bio 2021; 11:1867-1892. [PMID: 33715301 PMCID: PMC8255848 DOI: 10.1002/2211-5463.13143] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/18/2021] [Accepted: 03/11/2021] [Indexed: 12/18/2022] Open
Abstract
Buthus occitanus (B. occitanus) is one of the most dangerous scorpions in the world. Despite the involvement of B. occitanus scorpion in severe cases of envenomation in Morocco, no study has focused yet on the proteomic composition of the Moroccan B. occitanus scorpion venom. Mass spectrometry‐based proteomic techniques are commonly used in the study of scorpion venoms. The implementation of top‐down and bottom‐up approaches for proteomic analyses facilitates screening by allowing a global view of the structural aspects of such complex matrices. Here, we provide a partial overview of the venom of B. occitanus scorpion, in order to explore the diversity of its toxins and hereafter understand their effects. To this end, a combination of top‐down and bottom‐up approaches was applied using nano‐high liquid chromatography coupled to nano‐electrospray tandem mass spectrometry (nano‐LC‐ESI MS/MS). The LC‐MS results showed that B. occitanus venom contains around 200 molecular masses ranging from 1868 to 16 720 Da, the most representative of which are those between 5000 and 8000 Da. Interestingly, combined top‐down and bottom‐up LC‐MS/MS results allowed the identification of several toxins, which were mainly those acting on ion channels, including those targeting sodium (NaScTxs), potassium (KScTxs), chloride (ClScTxs), and calcium channels (CaScTx), as well as antimicrobial peptides (AMPs), amphipathic peptides, myotropic neuropeptides, and hypothetical secreted proteins. This study reveals the molecular diversity of B. occitanus scorpion venom and identifies components that may have useful pharmacological activities.
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Affiliation(s)
- Khadija Daoudi
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca, Morocco.,Laboratory of Molecular Genetics, Physiopathology and Biotechnology, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Morocco
| | - Christian Malosse
- Mass spectrometry for Biology Unit, Institut Pasteur, CNRS USR 2000, Paris, France
| | - Ayoub Lafnoune
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca, Morocco.,Laboratory of Molecular Genetics, Physiopathology and Biotechnology, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Morocco
| | - Bouchra Darkaoui
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca, Morocco.,Laboratory of Molecular Genetics, Physiopathology and Biotechnology, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Morocco
| | - Salma Chakir
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca, Morocco
| | | | - Julia Chamot-Rooke
- Mass spectrometry for Biology Unit, Institut Pasteur, CNRS USR 2000, Paris, France
| | - Rachida Cadi
- Laboratory of Molecular Genetics, Physiopathology and Biotechnology, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, Morocco
| | - Naoual Oukkache
- Laboratory of Venoms and Toxins, Pasteur Institute of Morocco, Casablanca, Morocco
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16
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Toledo EB, Lucas DR, Simão TLBV, Calixto SD, Lassounskaia E, Muzitano MF, Damica FZ, Gomes VM, de Oliveira Carvalho A. Design of improved synthetic antifungal peptides with targeted variations in charge, hydrophobicity and chirality based on a correlation study between biological activity and primary structure of plant defensin γ-cores. Amino Acids 2021; 53:219-237. [PMID: 33483849 DOI: 10.1007/s00726-020-02929-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/07/2020] [Indexed: 12/30/2022]
Abstract
Microbial resistance to available drugs is a growing health threat imposing the need for the development of new drugs. The scaffold of plant defensins, including their γ-cores, are particularly good candidates for drug design. This work aimed to improve the antifungal activity of a previous design peptide, named A36,42,44γ32-46VuDef (for short DD) against yeasts by altering its biochemical parameters. We explore the correlation of the biological activity and structure of plant defensins and compared their primary structures by superimposition with VuDef1 and DD which indicated us the favorable position and the amino acid to be changed. Three new peptides with modifications in charge, hydrophobicity (RR and WR) and chirality (D-RR) were designed and tested against pathogenic yeasts. Inhibition was determined by absorbance. Viability of mammalian cells was determined by MTT. The three designed peptides had better inhibitory activity against the yeasts with better potency and spectrum of yeast species inhibition, with low toxicity to mammalian cells. WR, the most hydrophobic and cationic, exhibited better antifungal activity and lower toxicity. Our study provides experimental evidence that targeted changes in the primary structure of peptides based on plant defensins γ-core primary structures prove to be a good tool for the synthesis of new compounds that may be useful as alternative antifungal drugs. The method described did not have the drawback of synthesis of several peptides, because alterations are guided. When compared to other methods, the design process described is efficient and viable to those with scarce resources.
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Affiliation(s)
- Estefany Braz Toledo
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, nº 2000, Campos dos Goytacazes, RJ, CEP 28013-602, Brazil
| | - Douglas Ribeiro Lucas
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, nº 2000, Campos dos Goytacazes, RJ, CEP 28013-602, Brazil
| | - Thatiana Lopes Biá Ventura Simão
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brazil
| | - Sanderson Dias Calixto
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brazil
| | - Elena Lassounskaia
- Laboratório de Biologia do Reconhecer, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, 28013-602, Brazil
| | - Michele Frazão Muzitano
- Laboratório de Produtos Bioativos, Curso de Farmácia, Universidade Federal do Rio de Janeiro, Campus Macaé, Pólo Novo Cavaleiro-IMMT, Macaé, RJ, 27933-378, Brazil
| | - Filipe Zanirati Damica
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, nº 2000, Campos dos Goytacazes, RJ, CEP 28013-602, Brazil
| | - Valdirene Moreira Gomes
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, nº 2000, Campos dos Goytacazes, RJ, CEP 28013-602, Brazil
| | - André de Oliveira Carvalho
- Laboratório de Fisiologia e Bioquímica de Microrganismos, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, nº 2000, Campos dos Goytacazes, RJ, CEP 28013-602, Brazil.
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17
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Günther A, Monod L, Wirkner CS. Comparative morphology of scorpion metasomata: Muscles and cuticle. ARTHROPOD STRUCTURE & DEVELOPMENT 2021; 60:101003. [PMID: 33444929 DOI: 10.1016/j.asd.2020.101003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 10/01/2020] [Accepted: 10/14/2020] [Indexed: 06/12/2023]
Abstract
Scorpions are among the most popular research objects within Arachnida and there is an impressive body of knowledge about their biology, distribution, morphology, etc. Although the poison sting has gained a lot of attention due to its potential lethal effects to humans, hitherto, there has been no comparative morphological study on the metasoma, the body part that delivers the poisonous injection. The metasoma always consists of five body segments terminated by a poison sting, but it presents significant morphological variations, both between sexes and between species. Its form ranges from long and thin to short and rather reduced to thick and dominant. In this study, we investigated species representing major scorpion clades and most of the known morphological disparity. Using high-resolution micro-computer-tomography and 3D-reconstruction, we present the first 3D visualizations of metasomal exo-skeletal elements in combination with their musculature. Despite of morphological varying metasomal forms, in all investigated species, a repeating pattern of muscles was found: four pairs of muscles in metasomal segment one to four and two pairs of muscles in metasomal segment five. However, the metasomal muscles are characterized by an antero-posterior change in their shapes and sizes and interspecific variation was also found in the extrinsic metasomal musculature, i.e. the muscles that link metasoma to mesosoma.
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Affiliation(s)
- Alice Günther
- Allgemeine & Spezielle Zoologie, Institut für Biowissenschaften, Universität Rostock, Germany.
| | - Lionel Monod
- Secteur Invertébrés, Muséum d'histoire Naturelle, Route de Malagnou 1, 1208, Genève, Switzerland
| | - Christian S Wirkner
- Allgemeine & Spezielle Zoologie, Institut für Biowissenschaften, Universität Rostock, Germany
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18
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Kalapothakis Y, Miranda K, Pereira AH, Witt ASA, Marani C, Martins AP, Leal HG, Campos-Júnior E, Pimenta AMC, Borges A, Chávez-Olórtegui C, Kalapothakis E. Novel components of Tityus serrulatus venom: A transcriptomic approach. Toxicon 2020; 189:91-104. [PMID: 33181162 DOI: 10.1016/j.toxicon.2020.11.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 10/01/2020] [Accepted: 11/08/2020] [Indexed: 12/13/2022]
Abstract
Several research groups have studied the components produced by the venom gland of the scorpion Tityus serrulatus, which has one of the most lethal venoms in the world. Various methodologies have been employed to clarify the complex mechanisms of action of these components, especially neurotoxins and enzymes. Transcriptomes and proteomes have provided important information for pharmacological, biochemical, and immunological research. Next-generation sequencing (NGS) has allowed the description of new transcripts and completion of partial sequence descriptions for peptides, especially those with low expression levels. In the present work, after NGS sequencing, we searched for new putative venom components. We present a total of nine new transcripts with neurotoxic potential (Ts33-41) and describe the sequences of one hyaluronidase (TsHyal_4); three enzymes involved in amidation (peptidyl-glycine alpha-amidating monooxygenase A, peptidyl-alpha-hydroxyglycine alpha-amidating lyase, and peptidylglycine alpha-hydroxylating monooxygenase), which increases the lethal potential of neurotoxins; and also the enzyme Ts_Chitinase1, which may be involved in the venom's digestive action. In addition, we determined the level of transcription of five groups: toxins, metalloproteases, hyaluronidases, chitinases and amidation enzymes, including new components found in this study. Toxins are the predominant group with an expression level of 91.945%, followed by metalloproteases with only 7.790% and other groups representing 0.265%.
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Affiliation(s)
- Yan Kalapothakis
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Kelton Miranda
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Adriana Heloísa Pereira
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Amanda S A Witt
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Camila Marani
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Ana Paula Martins
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Hortênsia Gomes Leal
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Edimar Campos-Júnior
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Adriano M C Pimenta
- Departamento de Bioquímica-Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Adolfo Borges
- Centro para el Desarrollo de la Investigación Científica (CEDIC), Manduvirá 635 c/15 de Agosto, Asunción, Paraguay
| | - Carlos Chávez-Olórtegui
- Departamento de Bioquímica-Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Evanguedes Kalapothakis
- Departamento de Genética, Ecologia e Evolução, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil.
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19
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Borges A, Lomonte B, Angulo Y, Acosta de Patiño H, Pascale JM, Otero R, Miranda RJ, De Sousa L, Graham MR, Gómez A, Pardal PP, Ishikawa E, Bonilla F, Castillo A, de Avila RAM, Gómez JP, Caro-López JA. Venom diversity in the Neotropical scorpion genus Tityus: Implications for antivenom design emerging from molecular and immunochemical analyses across endemic areas of scorpionism. Acta Trop 2020; 204:105346. [PMID: 31982434 DOI: 10.1016/j.actatropica.2020.105346] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 01/14/2020] [Accepted: 01/14/2020] [Indexed: 10/25/2022]
Abstract
Scorpions of the Neotropical genus Tityus are responsible for most severe envenomations in the Caribbean, South America, and Lower Central America (LCA). Although Tityus is taxonomically complex, contains high toxin polymorphism, and produces variable clinical manifestations, treatment is limited to antivenoms produced against species with restricted distributions. In this study, we explored the compositional and antigenic diversity of Tityus venoms to provide improved guidelines for the use of available antivenoms at a broader geographic scale. We used immunoblotting, competitive ELISA, and in vivo studies to compare reactivity against commercial antivenoms from Brazil, Venezuela, and Mexico, as well as MALDI-TOF mass spectrometry, cDNA sequencing, and phylogenetic analyses to assess venom sodium channel-active toxin (NaTx) content from medically important Tityus populations inhabiting Brazil, Colombia, Costa Rica, Ecuador, Panama, Trinidad and Tobago, and Venezuela. Additionally, we raised rabbit antibodies against Tityus venoms from LCA to test for cross-reactivity with congeneric species. The results suggest that Tityus spp. possess high venom antigenic diversity, underlying the existence of four toxinological regions in Tropical America, based on venom composition and immunochemical criteria: LCA/Colombia/Amazonia (Region I), Venezuela (Region II), southeast South America (Region III), and a fourth region encompassing species related to toxinologically divergent Tityus cerroazul. Importantly, our molecular and cross-reactivity results highlight the need for new antivenoms against species inhabiting Region I, where scorpions may produce venoms that are not significantly reactive against available antivenoms.
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20
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Jin J, Agwa AJ, Szanto TG, Csóti A, Panyi G, Schroeder CI, Walker AA, King GF. Weaponisation 'on the fly': Convergent recruitment of knottin and defensin peptide scaffolds into the venom of predatory assassin flies. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2020; 118:103310. [PMID: 31870846 DOI: 10.1016/j.ibmb.2019.103310] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/12/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Many arthropod venom peptides have potential as bioinsecticides, drug leads, and pharmacological tools due to their specific neuromodulatory functions. Assassin flies (Asilidae) are a family of predaceous dipterans that produce a unique and complex peptide-rich venom for killing insect prey and deterring predators. However, very little is known about the structure and function of their venom peptides. We therefore used an E. coli periplasmic expression system to express four disulfide-rich peptides that we previously reported to exist in venom of the giant assassin fly Dolopus genitalis. After purification, each recombinant peptide eluted from a C18 column at a position closely matching its natural counterpart, strongly suggesting adoption of the native tertiary fold. Injection of purified recombinant peptides into blowflies (Lucilia cuprina) and crickets (Acheta domestica) revealed that two of the four recombinant peptides, named rDg3b and rDg12, inhibited escape behaviour in a manner that was rapid in onset (<1 min) and reversible. Homonuclear NMR solution structures revealed that rDg3b and rDg12 adopt cystine-stabilised α/ß defensin and inhibitor cystine knot folds, respectively. Although the closest known homologues of rDg3b at the level of primary structure are dipteran antimicrobial peptides such as sapecin and lucifensin, a DALI search showed that the tertiary structure of rDg3b most closely resembles the KV11.1-specific α-potassium channel toxin CnErg1 from venom of the scorpion Centruroides noxius. This is mainly due to the deletion of a large, unstructured loop between the first and second cysteine residues present in Dg3b homologues from non-asiloid, but not existing in asiloid, species. Patch-clamp electrophysiology experiments revealed that rDg3b shifts the voltage-dependence of KV11.1 channel activation to more depolarised potentials, but has no effect on KV1.3, KV2.1, KV10.1, KCa1.1, or the Drosophila Shaker channel. Although rDg12 shares the inhibitor cystine knot structure of many gating modifier toxins, rDg12 did not affect any of these KV channel subtypes. Our results demonstrate that multiple disulfide-rich peptide scaffolds have been convergently recruited into asilid and other animal venoms, and they provide insight into the molecular evolution accompanying their weaponisation.
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Affiliation(s)
- Jiayi Jin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Akello J Agwa
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Tibor G Szanto
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Agota Csóti
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, H-4032, Hungary
| | - Christina I Schroeder
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia.
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21
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Chow CY, Chin YKY, Walker AA, Guo S, Blomster LV, Ward MJ, Herzig V, Rokyta DR, King GF. Venom Peptides with Dual Modulatory Activity on the Voltage-Gated Sodium Channel Na V1.1 Provide Novel Leads for Development of Antiepileptic Drugs. ACS Pharmacol Transl Sci 2019; 3:119-134. [PMID: 32259093 DOI: 10.1021/acsptsci.9b00079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Indexed: 01/14/2023]
Abstract
Voltage-gated sodium (NaV) channels play a fundamental role in normal neurological function, especially via the initiation and propagation of action potentials. The NaV1.1 subtype is found in inhibitory interneurons of the brain and it is essential for maintaining a balance between excitation and inhibition in neuronal networks. Heterozygous loss-of-function mutations of SCN1A, the gene encoding NaV1.1, underlie Dravet syndrome (DS), a severe pediatric epilepsy. We recently demonstrated that selective inhibition of NaV1.1 inactivation prevents seizures and premature death in a mouse model of DS. Thus, selective modulators of NaV1.1 might be useful therapeutics for treatment of DS as they target the underlying molecular deficit. Numerous scorpion-venom peptides have been shown to modulate the activity of NaV channels, but little is known about their activity at NaV1.1. Here we report the isolation, sequence, three-dimensional structure, recombinant production, and functional characterization of two peptidic modulators of NaV1.1 from venom of the buthid scorpion Hottentotta jayakari. These peptides, Hj1a and Hj2a, are potent agonists of NaV1.1 (EC50 of 17 and 32 nM, respectively), and they present dual α/β activity by modifying both the activation and inactivation properties of the channel. NMR studies of rHj1a indicate that it adopts a cystine-stabilized αβ fold similar to known scorpion toxins. Although Hj1a and Hj2a have only limited selectivity for NaV1.1, their unusual dual mode of action provides an alternative approach to the development of selective NaV1.1 modulators for the treatment of DS.
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Affiliation(s)
- Chun Yuen Chow
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Yanni K-Y Chin
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Shaodong Guo
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Linda V Blomster
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Micaiah J Ward
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Darin R Rokyta
- Department of Biological Science, Florida State University, Tallahassee, Florida 32306, United States
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
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22
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Hadrurid Scorpion Toxins: Evolutionary Conservation and Selective Pressures. Toxins (Basel) 2019; 11:toxins11110637. [PMID: 31683932 PMCID: PMC6891616 DOI: 10.3390/toxins11110637] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/30/2019] [Accepted: 10/30/2019] [Indexed: 12/18/2022] Open
Abstract
Scorpion toxins are thought to have originated from ancestral housekeeping genes that underwent diversification and neofunctionalization, as a result of positive selection. Our understanding of the evolutionary origin of these peptides is hindered by the patchiness of existing taxonomic sampling. While recent studies have shown phylogenetic inertia in some scorpion toxins at higher systematic levels, evolutionary dynamics of toxins among closely related taxa remain unexplored. In this study, we used new and previously published transcriptomic resources to assess evolutionary relationships of closely related scorpions from the family Hadruridae and their toxins. In addition, we surveyed the incidence of scorpine-like peptides (SLP, a type of potassium channel toxin), which were previously known from 21 scorpion species. We demonstrate that scorpine-like peptides exhibit gene duplications. Our molecular analyses demonstrate that only eight sites of two SLP copies found in scorpions are evolving under positive selection, with more sites evolving under negative selection, in contrast to previous findings. These results show evolutionary conservation in toxin diversity at shallow taxonomic scale.
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Spider Venom: Components, Modes of Action, and Novel Strategies in Transcriptomic and Proteomic Analyses. Toxins (Basel) 2019; 11:toxins11100611. [PMID: 31652611 PMCID: PMC6832493 DOI: 10.3390/toxins11100611] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 10/18/2019] [Indexed: 12/19/2022] Open
Abstract
This review gives an overview on the development of research on spider venoms with a focus on structure and function of venom components and techniques of analysis. Major venom component groups are small molecular mass compounds, antimicrobial (also called cytolytic, or cationic) peptides (only in some spider families), cysteine-rich (neurotoxic) peptides, and enzymes and proteins. Cysteine-rich peptides are reviewed with respect to various structural motifs, their targets (ion channels, membrane receptors), nomenclature, and molecular binding. We further describe the latest findings concerning the maturation of antimicrobial, and cysteine-rich peptides that are in most known cases expressed as propeptide-containing precursors. Today, venom research, increasingly employs transcriptomic and mass spectrometric techniques. Pros and cons of venom gland transcriptome analysis with Sanger, 454, and Illumina sequencing are discussed and an overview on so far published transcriptome studies is given. In this respect, we also discuss the only recently described cross contamination arising from multiplexing in Illumina sequencing and its possible impacts on venom studies. High throughput mass spectrometric analysis of venom proteomes (bottom-up, top-down) are reviewed.
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Díaz C, Rivera J, Lomonte B, Bonilla F, Diego-García E, Camacho E, Tytgat J, Sasa M. Venom characterization of the bark scorpion Centruroides edwardsii (Gervais 1843): Composition, biochemical activities and in vivo toxicity for potential prey. Toxicon 2019; 171:7-19. [PMID: 31585140 DOI: 10.1016/j.toxicon.2019.09.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/21/2019] [Accepted: 09/25/2019] [Indexed: 02/07/2023]
Abstract
In this study, we characterize the venom of Centruroides edwardsii, one of the most abundant scorpions in urban and rural areas of Costa Rica, in terms of its biochemical constituents and their biological activities. C. edwardsii venom is rich in peptides but also contains some higher molecular weight protein components. No phospholipase A2, hemolytic or fibrinogenolytic activities were found, but the presence of proteolytic and hyaluronidase enzymes was evidenced by zymography. Venom proteomic analysis indicates the presence of a hyaluronidase, several cysteine-rich secretory proteins, metalloproteinases and a peptidylglycine α-hydroxylating monooxygenase like-enzyme. It also includes peptides similar to the K+-channel blocker margatoxin, a dominant toxin in the venom of the related scorpion C. margaritatus. MS and N-terminal sequencing analysis also reveals the presence of Na+-channel-modulating peptides with sequence similarity to orthologs present in other scorpion species of the genera Centruroides and Tityus. We purified the hyaluronidase (which co-eluted with an allergen 5-like CRiSP) and sequenced ~60% of this enzyme. We also sequenced some venom gland transcripts that include other cysteine-containing peptides and a Non-Disulfide Bridged Peptide (NDBP). Our in vivo experiments characterizing the effects on potential predators and prey show that C. edwardsii venom induces paralysis in several species of arthropods and geckos; crickets being the most sensitive and cockroaches and scorpions the most resistant organisms tested. Envenomation signs were also observed in mice, but no lethality was reached by intraperitoneal administration of this venom up to 120 μg/g body weight.
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Affiliation(s)
- Cecilia Díaz
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica; Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica.
| | - Jennifer Rivera
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Fabián Bonilla
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Elia Diego-García
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Belgium
| | - Erika Camacho
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Belgium
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiología, San José, Costa Rica; Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
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Lin King JV, Emrick JJ, Kelly MJS, Herzig V, King GF, Medzihradszky KF, Julius D. A Cell-Penetrating Scorpion Toxin Enables Mode-Specific Modulation of TRPA1 and Pain. Cell 2019; 178:1362-1374.e16. [PMID: 31447178 DOI: 10.1016/j.cell.2019.07.014] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/23/2019] [Accepted: 07/11/2019] [Indexed: 02/01/2023]
Abstract
TRPA1 is a chemosensory ion channel that functions as a sentinel for structurally diverse electrophilic irritants. Channel activation occurs through an unusual mechanism involving covalent modification of cysteine residues clustered within an amino-terminal cytoplasmic domain. Here, we describe a peptidergic scorpion toxin (WaTx) that activates TRPA1 by penetrating the plasma membrane to access the same intracellular site modified by reactive electrophiles. WaTx stabilizes TRPA1 in a biophysically distinct active state characterized by prolonged channel openings and low Ca2+ permeability. Consequently, WaTx elicits acute pain and pain hypersensitivity but fails to trigger efferent release of neuropeptides and neurogenic inflammation typically produced by noxious electrophiles. These findings provide a striking example of convergent evolution whereby chemically disparate animal- and plant-derived irritants target the same key allosteric regulatory site to differentially modulate channel activity. WaTx is a unique pharmacological probe for dissecting TRPA1 function and its contribution to acute and persistent pain.
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Affiliation(s)
- John V Lin King
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Joshua J Emrick
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA; Oral and Craniofacial Sciences Program, School of Dentistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Mark J S Kelly
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Volker Herzig
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Glenn F King
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Katalin F Medzihradszky
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David Julius
- Department of Physiology, University of California, San Francisco, San Francisco, CA 94143, USA.
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Grashof DGB, Kerkkamp HMI, Afonso S, Archer J, Harris DJ, Richardson MK, Vonk FJ, van der Meijden A. Transcriptome annotation and characterization of novel toxins in six scorpion species. BMC Genomics 2019; 20:645. [PMID: 31409288 PMCID: PMC6693263 DOI: 10.1186/s12864-019-6013-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 08/02/2019] [Indexed: 02/08/2023] Open
Abstract
Background Venom has evolved in parallel in multiple animals for the purpose of self-defense, prey capture or both. These venoms typically consist of highly complex mixtures of toxins: diverse bioactive peptides and/or proteins each with a specific pharmacological activity. Because of their specificity, they can be used as experimental tools to study cell mechanisms and develop novel medicines and drugs. It is therefore potentially valuable to explore the venoms of various animals to characterize their toxins and identify novel toxin-families. This study focuses on the annotation and exploration of the transcriptomes of six scorpion species from three different families. The transcriptomes were annotated with a custom-built automated pipeline, primarily consisting of Basic Local Alignment Search Tool searches against UniProt databases and filter steps based on transcript coverage. Results We annotated the transcriptomes of four scorpions from the family Buthidae, one from Iuridae and one from Diplocentridae using our annotation pipeline. We found that the four buthid scorpions primarily produce disulfide-bridged ion-channel targeting toxins, while the non-buthid scorpions have a higher abundance of non-disulfide-bridged toxins. Furthermore, analysis of the “unidentified” transcripts resulted in the discovery of six novel putative toxin families containing a total of 37 novel putative toxins. Additionally, 33 novel toxins in existing toxin-families were found. Lastly, 19 novel putative secreted proteins without toxin-like disulfide bonds were found. Conclusions We were able to assign most transcripts to a toxin family and classify the venom composition for all six scorpions. In addition to advancing our fundamental knowledge of scorpion venomics, this study may serve as a starting point for future research by facilitating the identification of the venom composition of scorpions and identifying novel putative toxin families. Electronic supplementary material The online version of this article (10.1186/s12864-019-6013-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | | | - Freek J Vonk
- IBL, Leiden University, Leiden, The Netherlands.,Naturalis Biodiversity Center Leiden, Leiden, The Netherlands
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Evans ERJ, Northfield TD, Daly NL, Wilson DT. Venom Costs and Optimization in Scorpions. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00196] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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Yao T, Lu J, Ye L, Wang J. Molecular characterization and immune analysis of a defensin from small abalone, Haliotis diversicolor. Comp Biochem Physiol B Biochem Mol Biol 2019; 235:1-7. [PMID: 31078702 DOI: 10.1016/j.cbpb.2019.05.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 04/18/2019] [Accepted: 05/06/2019] [Indexed: 01/09/2023]
Abstract
As one of antimicrobial peptides (AMPs), defensins are involved in invertebrate innate immunity against invading pathogens. In this study, a member of the invertebrate defensins was cloned and characterized from the small abalone Haliotis diversicolor, designated HdDef-2. The HdDef-2 cDNA contained a 201 bp open reading frame encoding 66 amino acids including a signal peptide of 18 amino acids and a mature peptide of 48 amino acids. The mature peptide of HdDef-2 possessed similar features to other AMPs, such as lower molecular mass, net positive charge (+1), and a high hydrophobic residue ratio (45%). In addition, six cysteines in the mature peptide were arranged in the pattern C-X16-C-X3-C-X9-C-X4-C-X1-C and stabilized the α-helix/β-sheet motif (CSαβ) with three disulfide bonds (C1-C4, C2-C5 and C3-C6) in the predicted tertiary structure. Moreover, the similar three-dimensional structure to Anopheles gambiae defensin and a phylogenetic analysis suggest that HdDef-2 may be a new member of the arthropod defensin family. Quantitative real-time PCR analysis revealed that HdDef-2 transcripts were constitutively expressed in the mantle, gill, hepatopancreas, and foot, with the highest level in the hepatopancreas. It was observed that HdDef-2 transcripts were significantly induced in the hepatopancreas after infection by Vibrio harveyi. These results indicate that HdDef-2 may be involved in the immune response against invading pathogenic bacteria, but future work is needed to verify its antimicrobial activity in protein level and elucidate the underlying mechanisms.
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Affiliation(s)
- Tuo Yao
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou Guangdong 510300, PR China
| | - Jie Lu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou Guangdong 510300, PR China
| | - Lingtong Ye
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou Guangdong 510300, PR China
| | - Jiangyong Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou Guangdong 510300, PR China.
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Surm JM, Smith HL, Madio B, Undheim EA, King GF, Hamilton BR, Burg CA, Pavasovic A, Prentis PJ. A process of convergent amplification and tissue‐specific expression dominates the evolution of toxin and toxin‐like genes in sea anemones. Mol Ecol 2019; 28:2272-2289. [DOI: 10.1111/mec.15084] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/09/2019] [Accepted: 03/18/2019] [Indexed: 02/06/2023]
Affiliation(s)
- Joachim M. Surm
- Faculty of Health, School of Biomedical Sciences Queensland University of Technology Kelvin Grove Queensland Australia
- Institute of Health and Biomedical Innovation Queensland University of Technology Kelvin Grove Queensland Australia
| | - Hayden L. Smith
- Science and Engineering Faculty, School of Earth, Environmental and Biological Sciences Queensland University of Technology Brisbane Queensland Australia
- Institute for Future Environments Queensland University of Technology Brisbane Queensland Australia
| | - Bruno Madio
- Institute for Molecular Bioscience University of Queensland Brisbane Queensland Australia
| | - Eivind A.B. Undheim
- Centre for Advanced Imaging University of Queensland Saint Lucia Queensland Australia
| | - Glenn F. King
- Institute for Molecular Bioscience University of Queensland Brisbane Queensland Australia
| | - Brett R. Hamilton
- Centre for Advanced Imaging University of Queensland Saint Lucia Queensland Australia
- Centre for Microscopy and Microanalysis University of Queensland Saint Lucia Queensland Australia
| | - Chloé A. Burg
- Faculty of Health, School of Biomedical Sciences Queensland University of Technology Kelvin Grove Queensland Australia
- Institute of Health and Biomedical Innovation Queensland University of Technology Kelvin Grove Queensland Australia
| | - Ana Pavasovic
- Faculty of Health, School of Biomedical Sciences Queensland University of Technology Kelvin Grove Queensland Australia
| | - Peter J. Prentis
- Science and Engineering Faculty, School of Earth, Environmental and Biological Sciences Queensland University of Technology Brisbane Queensland Australia
- Institute for Future Environments Queensland University of Technology Brisbane Queensland Australia
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Rojas-Azofeifa D, Sasa M, Lomonte B, Diego-García E, Ortiz N, Bonilla F, Murillo R, Tytgat J, Díaz C. Biochemical characterization of the venom of Central American scorpion Didymocentrus krausi Francke, 1978 (Diplocentridae) and its toxic effects in vivo and in vitro. Comp Biochem Physiol C Toxicol Pharmacol 2019; 217:54-67. [PMID: 30517877 DOI: 10.1016/j.cbpc.2018.11.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/27/2018] [Accepted: 11/28/2018] [Indexed: 11/28/2022]
Abstract
Venoms of medically important scorpions from Buthidae family have been intensively studied, in contrast to non-buthid venoms, for which knowledge is scarce. In this work, we characterized the venom of a Diplocentridae species, Didymocentrus krausi, a small fossorial scorpion that inhabits the Tropical Dry Forest of Central America. D. krausi venom soluble fraction contains proteases with enzymatic activity on gelatin and casein. Mass spectrometry and venomic analysis confirmed the presence of elastase-like, cathepsin-O-like proteases and a neprilysin-like metalloproteinase. We did not detect phospholipase A2, C or D, nor hyaluronidase activity in the venom. By homology-based venom gland transcriptomic analysis, NDBPs, a β-KTx-like peptide, and other putative toxin transcripts were found, which, together with a p-benzoquinone compound present in the venom, could potentially explain its direct hemolytic and cytotoxic effects in several mammalian cell lines. Cytotoxicity of D. krausi venom was higher than the effect of venoms from two buthid scorpion species distributed in Costa Rica, Centruroides edwardsii and Tityus pachyurus. Even though D. krausi venom was not lethal to mice or crickets, when injected in mouse gastrocnemius muscle at high doses it induced pathological effects at 24 h, which include myonecrosis, weak hemorrhage, and inflammatory infiltration. We observed an apparent thrombotic effect in the skin blood vessels, but no in vitro fibrinogenolytic activity was detected. In crickets, D. krausi venom induced toxicity and paralysis in short periods of time.
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Affiliation(s)
- Daniela Rojas-Azofeifa
- Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica; Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Mahmood Sasa
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica; Escuela de Biología, Universidad de Costa Rica, San José, Costa Rica
| | - Bruno Lomonte
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Elia Diego-García
- Cátedras CONACYT-El Colegio de la Frontera Sur (ECOSUR), Tapachula, Chiapas, Mexico; Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Belgium
| | - Natalia Ortiz
- Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica; Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Fabián Bonilla
- Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica
| | - Renato Murillo
- Centro de Investigaciones en Productos Naturales, Universidad de Costa Rica, San José, Costa Rica
| | - Jan Tytgat
- Department of Pharmaceutical and Pharmacological Sciences, University of Leuven, Belgium
| | - Cecilia Díaz
- Departamento de Bioquímica, Escuela de Medicina, Universidad de Costa Rica, San José, Costa Rica; Instituto Clodomiro Picado, Facultad de Microbiología, Universidad de Costa Rica, San José, Costa Rica.
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Silva F, Huang Y, Yang V, Mu X, Shi Q, Antunes A. Transcriptomic Characterization of the South American Freshwater Stingray Potamotrygon motoro Venom Apparatus. Toxins (Basel) 2018; 10:E544. [PMID: 30567320 PMCID: PMC6315956 DOI: 10.3390/toxins10120544] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/14/2018] [Accepted: 12/14/2018] [Indexed: 01/16/2023] Open
Abstract
Venomous animals are found through a wide taxonomic range including cartilaginous fish such as the freshwater stingray Potamotrygon motoro occurring in South America, which can injure people and cause venom-related symptoms. Ensuring the efficacy of drug development to treat stingray injuries can be assisted by the knowledge of the venom composition. Here we performed a detailed transcriptomic characterization of the venom gland of the South American freshwater stingray Potamotrygon motoro. The transcripts retrieved showed 418 hits to venom components (comparably to 426 and 396 hits in other two Potamotrygon species), with high expression levels of hyaluronidase, cystatin and calglandulin along with hits uniquely found in P. motoro such as DELTA-alicitoxin-Pse1b, Augerpeptide hhe53 and PI-actitoxin-Aeq3a. We also identified undescribed molecules with extremely high expression values with sequence similarity to the SE-cephalotoxin and Rapunzel genes. Comparative analyses showed that despite being closely related, there may be significant variation among the venoms of freshwater stingrays, highlighting the importance of considering elicit care in handling different envenomation cases. Since hyaluronidase represents a major component of fish venom, we have performed phylogenetic and selective pressure analyses of this gene/protein across all fish with the available information. Results indicated an independent recruitment of the hyaluronidase into the stingray venom relative to that of venomous bony fish. The hyaluronidase residues were found to be mostly under negative selection, but 18 sites showed evidence of diversifying positive selection (P < 0.05). Our data provides new insight into stingray venom variation, composition, and selective pressure in hyaluronidase.
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Affiliation(s)
- Filipe Silva
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal.
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal.
| | - Yu Huang
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI Academy of Marine Sciences, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Vítor Yang
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal.
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal.
| | - Xidong Mu
- Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Key Laboratory of Recreational Fisheries, Ministry of Agriculture, Guangdong Engineering Technology Research Center for Advanced Recreational Fisheries, Guangzhou 510380, 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, Shenzhen 518083, China.
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen 518083, China.
| | - Agostinho Antunes
- CIIMAR/CIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Av. General Norton de Matos, s/n, 4450-208 Porto, Portugal.
- Department of Biology, Faculty of Sciences, University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal.
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Arthropod venoms: Biochemistry, ecology and evolution. Toxicon 2018; 158:84-103. [PMID: 30529476 DOI: 10.1016/j.toxicon.2018.11.433] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Revised: 11/20/2018] [Accepted: 11/26/2018] [Indexed: 12/17/2022]
Abstract
Comprising of over a million described species of highly diverse invertebrates, Arthropoda is amongst the most successful animal lineages to have colonized aerial, terrestrial, and aquatic domains. Venom, one of the many fascinating traits to have evolved in various members of this phylum, has underpinned their adaptation to diverse habitats. Over millions of years of evolution, arthropods have evolved ingenious ways of delivering venom in their targets for self-defence and predation. The morphological diversity of venom delivery apparatus in arthropods is astounding, and includes extensively modified pedipalps, tail (telson), mouth parts (hypostome), fangs, appendages (maxillulae), proboscis, ovipositor (stinger), and hair (urticating bristles). Recent investigations have also unravelled an astonishing venom biocomplexity with molecular scaffolds being recruited from a multitude of protein families. Venoms are a remarkable bioresource for discovering lead compounds in targeted therapeutics. Several components with prospective applications in the development of advanced lifesaving drugs and environment friendly bio-insecticides have been discovered from arthropod venoms. Despite these fascinating features, the composition, bioactivity, and molecular evolution of venom in several arthropod lineages remains largely understudied. This review highlights the prevalence of venom, its mode of toxic action, and the evolutionary dynamics of venom in Arthropoda, the most speciose phylum in the animal kingdom.
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Santibáñez-López CE, Kriebel R, Ballesteros JA, Rush N, Witter Z, Williams J, Janies DA, Sharma PP. Integration of phylogenomics and molecular modeling reveals lineage-specific diversification of toxins in scorpions. PeerJ 2018; 6:e5902. [PMID: 30479892 PMCID: PMC6240337 DOI: 10.7717/peerj.5902] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 10/09/2018] [Indexed: 12/25/2022] Open
Abstract
Scorpions have evolved a variety of toxins with a plethora of biological targets, but characterizing their evolution has been limited by the lack of a comprehensive phylogenetic hypothesis of scorpion relationships grounded in modern, genome-scale datasets. Disagreements over scorpion higher-level systematics have also incurred challenges to previous interpretations of venom families as ancestral or derived. To redress these gaps, we assessed the phylogenomic relationships of scorpions using the most comprehensive taxonomic sampling to date. We surveyed genomic resources for the incidence of calcins (a type of calcium channel toxin), which were previously known only from 16 scorpion species. Here, we show that calcins are diverse, but phylogenetically restricted only to parvorder Iurida, one of the two basal branches of scorpions. The other branch of scorpions, Buthida, bear the related LKTx toxins (absent in Iurida), but lack calcins entirely. Analysis of sequences and molecular models demonstrates remarkable phylogenetic inertia within both calcins and LKTx genes. These results provide the first synapomorphies (shared derived traits) for the recently redefined clades Buthida and Iurida, constituting the only known case of such traits defined from the morphology of molecules.
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Affiliation(s)
| | - Ricardo Kriebel
- Department of Botany, University of Wisconsin-Madison, Madison, WI, USA
| | - Jesús A. Ballesteros
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Nathaniel Rush
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Zachary Witter
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - John Williams
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Daniel A. Janies
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, USA
| | - Prashant P. Sharma
- Department of Integrative Biology, University of Wisconsin-Madison, Madison, WI, USA
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Walker AA, Dobson J, Jin J, Robinson SD, Herzig V, Vetter I, King GF, Fry BG. Buzz Kill: Function and Proteomic Composition of Venom from the Giant Assassin Fly Dolopus genitalis (Diptera: Asilidae). Toxins (Basel) 2018; 10:toxins10110456. [PMID: 30400621 PMCID: PMC6266666 DOI: 10.3390/toxins10110456] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 10/31/2018] [Accepted: 11/01/2018] [Indexed: 11/24/2022] Open
Abstract
Assassin flies (Diptera: Asilidae) inject paralysing venom into insect prey during hunting, but their venoms are poorly characterised in comparison to those produced by spiders, scorpions, or hymenopteran insects. Here we investigated the composition of the venom of the giant Australian assassin fly Dolopus genitalis using a combination of insect microinjection assays, calcium imaging assays of mammalian sensory neurons, proteomics and transcriptomics. Injection of venom into blowflies (Lucilia cuprina) produced rapid contractile paralysis (PD50 at 1 min = 3.1 μg per fly) followed by death, and also caused immediate activation of mouse dorsal root ganglion neurons (at 50 ng/μL). These results are consistent with venom use for both prey capture and predator deterrence. Paragon searches of tandem mass spectra of venom against a translated thoracic gland RNA-Seq database identified 122 polypeptides present in the venom, including six linear and 21 disulfide-rich peptides. Some of these disulfide-rich peptides display sequence homology to peptide families independently recruited into other animal venoms, including inhibitor cystine knots, cystine-stabilised α/β defensins, Kazal peptides, and von Willebrand factors. Numerous enzymes are present in the venom, including 35 proteases of the S1 family, proteases of the S10, C1A, M12A, M14, and M17 families, and phosphatase, amylase, hydrolase, nuclease, and dehydrogenase-like proteins. These results highlight convergent molecular evolution between the assassin flies and other venomous animals, as well as the unique and rich molecular composition of assassin fly venom.
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Affiliation(s)
- Andrew A Walker
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - James Dobson
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Jiayi Jin
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Samuel D Robinson
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.
- Centre for Advanced Imaging, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Volker Herzig
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Irina Vetter
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.
- School of Pharmacy, The University of Queensland, Woolloongabba, QLD 4102, Australia.
| | - Glenn F King
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD 4072, Australia.
| | - Bryan G Fry
- Venom Evolution Lab, School of Biological Sciences, The University of Queensland, St Lucia, QLD 4072, Australia.
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B Orts DJ, Peigneur S, Silva-Gonçalves LC, Arcisio-Miranda M, P W Bicudo JE, Tytgat J. AbeTx1 Is a Novel Sea Anemone Toxin with a Dual Mechanism of Action on Shaker-Type K⁺ Channels Activation. Mar Drugs 2018; 16:md16100360. [PMID: 30275388 PMCID: PMC6213216 DOI: 10.3390/md16100360] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 09/25/2018] [Accepted: 09/29/2018] [Indexed: 12/19/2022] Open
Abstract
Voltage-gated potassium (KV) channels regulate diverse physiological processes and are an important target for developing novel therapeutic approaches. Sea anemone (Cnidaria, Anthozoa) venoms comprise a highly complex mixture of peptide toxins with diverse and selective pharmacology on KV channels. From the nematocysts of the sea anemone Actinia bermudensis, a peptide that we named AbeTx1 was purified and functionally characterized on 12 different subtypes of KV channels (KV1.1⁻KV1.6; KV2.1; KV3.1; KV4.2; KV4.3; KV11.1; and, Shaker IR), and three voltage-gated sodium channel isoforms (NaV1.2, NaV1.4, and BgNaV). AbeTx1 was selective for Shaker-related K⁺ channels and is capable of inhibiting K⁺ currents, not only by blocking the K⁺ current of KV1.2 subtype, but by altering the energetics of activation of KV1.1 and KV1.6. Moreover, experiments using six synthetic alanine point-mutated analogs further showed that a ring of basic amino acids acts as a multipoint interaction for the binding of the toxin to the channel. The AbeTx1 primary sequence is composed of 17 amino acids with a high proportion of lysines and arginines, including two disulfide bridges (Cys1⁻Cys4 and Cys2⁻Cys3), and it is devoid of aromatic or aliphatic amino acids. Secondary structure analysis reveals that AbeTx1 has a highly flexible, random-coil-like conformation, but with a tendency of structuring in the beta sheet. Its overall structure is similar to open-ended cyclic peptides found on the scorpion κ-KTx toxins family, cone snail venoms, and antimicrobial peptides.
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Affiliation(s)
- Diego J B Orts
- Department of Physiology, Institute of Biosciences, University of São Paulo, 05508-090 São Paulo, Brazil.
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
| | - Laíz Costa Silva-Gonçalves
- Laboratório de Neurobiologia Estrutural e Funcional (LaNEF), Departamento de Biofísica, Universidade Federal de São Paulo, 04023-062 São Paulo, Brazil.
| | - Manoel Arcisio-Miranda
- Laboratório de Neurobiologia Estrutural e Funcional (LaNEF), Departamento de Biofísica, Universidade Federal de São Paulo, 04023-062 São Paulo, Brazil.
| | - José Eduardo P W Bicudo
- Department of Physiology, Institute of Biosciences, University of São Paulo, 05508-090 São Paulo, Brazil.
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg O&N2, Herestraat 49, P.O. Box 922, 3000 Leuven, Belgium.
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The diversity of venom components of the scorpion species Paravaejovis schwenkmeyeri (Scorpiones: Vaejovidae) revealed by transcriptome and proteome analyses. Toxicon 2018; 151:47-62. [DOI: 10.1016/j.toxicon.2018.06.085] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 06/20/2018] [Accepted: 06/25/2018] [Indexed: 12/11/2022]
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37
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Structural diversity of arthropod venom toxins. Toxicon 2018; 152:46-56. [DOI: 10.1016/j.toxicon.2018.07.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 06/29/2018] [Accepted: 07/19/2018] [Indexed: 11/19/2022]
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38
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Baumann K, Dashevsky D, Sunagar K, Fry B. Scratching the Surface of an Itch: Molecular Evolution of Aculeata Venom Allergens. J Mol Evol 2018; 86:484-500. [DOI: 10.1007/s00239-018-9860-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
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The role of the arginine residue in site RC for the analgesic activity of the recombinant Chinese scorpion Buthus martensii Karsch, BmK AGP-SYPU1. Comput Biol Chem 2018; 74:247-252. [PMID: 29665474 DOI: 10.1016/j.compbiolchem.2018.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/03/2018] [Accepted: 04/08/2018] [Indexed: 01/05/2023]
Abstract
Scorpion venom is composed of a large number of bioactive peptides which display important pharmacological activities. In this study we have carried out a study of the functional role of the arginine residue at position 58 in the site RC comprising the reverse turn (8-12) and C-terminal residues 58-64. A polymerase chain reaction was used to substitute this arginine residue with a single amino acid such as alanine, glycine and lysine. The mutants were expressed in soluble form in E. coli, and purified by affinity chromatography. After target peptide purity identification, the recombinant peptides underwent a circular dichroism analysis and a study of their analgesic activity in mice. The results indicated that a single residue modification can affect the pharmacological activity. Our efforts establish a sound basis for further study of the structure-function determinants of the analgesic effect.
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40
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Pienaar R, Neitz AWH, Mans BJ. Tick Paralysis: Solving an Enigma. Vet Sci 2018; 5:E53. [PMID: 29757990 PMCID: PMC6024606 DOI: 10.3390/vetsci5020053] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Revised: 05/04/2018] [Accepted: 05/09/2018] [Indexed: 11/17/2022] Open
Abstract
In comparison to other arachnids, ticks are major vectors of disease, but less than 8% of the known species are capable of inducing paralysis, as compared to the ~99⁻100% arachnids that belong to venomous classes. When considering the potential monophyly of venomous Arachnida, this review reflects on the implications regarding the classification of ticks as venomous animals and the possible origin of toxins. The origin of tick toxins is compared with scorpion and spider toxins and venoms based on their significance, functionality, and structure in the search to find homologous venomous characters. Phenotypic evaluation of paralysis, as caused by different ticks, demonstrated the need for expansion on existing molecular data of pure isolated tick toxins because of differences and discrepancies in available data. The use of in-vivo, in-vitro, and in-silico assays for the purification and characterization of paralysis toxins were critically considered, in view of what may be considered to be a paralysis toxin. Purified toxins should exhibit physiologically relevant activity to distinguish them from other tick-derived proteins. A reductionist approach to identify defined tick proteins will remain as paramount in the search for defined anti-paralysis vaccines.
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Affiliation(s)
- Ronel Pienaar
- Epidemiology, Parasites and Vectors, Agricultural Research Council⁻Onderstepoort Veterinary Research, Onderstepoort, Pretoria 0110, South Africa.
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa.
| | - Albert W H Neitz
- Division of Biochemistry, University of Pretoria, Hatfield, Pretoria 0028, South Africa.
| | - Ben J Mans
- Epidemiology, Parasites and Vectors, Agricultural Research Council⁻Onderstepoort Veterinary Research, Onderstepoort, Pretoria 0110, South Africa.
- Department of Veterinary Tropical Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, Pretoria 0110, South Africa.
- Department of Life and Consumer Sciences, University of South Africa, Florida, Johannesburg 1710, South Africa.
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41
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Ojeda PG, Ramírez D, Alzate-Morales J, Caballero J, Kaas Q, González W. Computational Studies of Snake Venom Toxins. Toxins (Basel) 2017; 10:E8. [PMID: 29271884 PMCID: PMC5793095 DOI: 10.3390/toxins10010008] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 12/09/2017] [Accepted: 12/18/2017] [Indexed: 12/17/2022] Open
Abstract
Most snake venom toxins are proteins, and participate to envenomation through a diverse array of bioactivities, such as bleeding, inflammation, and pain, cytotoxic, cardiotoxic or neurotoxic effects. The venom of a single snake species contains hundreds of toxins, and the venoms of the 725 species of venomous snakes represent a large pool of potentially bioactive proteins. Despite considerable discovery efforts, most of the snake venom toxins are still uncharacterized. Modern bioinformatics tools have been recently developed to mine snake venoms, helping focus experimental research on the most potentially interesting toxins. Some computational techniques predict toxin molecular targets, and the binding mode to these targets. This review gives an overview of current knowledge on the ~2200 sequences, and more than 400 three-dimensional structures of snake toxins deposited in public repositories, as well as of molecular modeling studies of the interaction between these toxins and their molecular targets. We also describe how modern bioinformatics have been used to study the snake venom protein phospholipase A2, the small basic myotoxin Crotamine, and the three-finger peptide Mambalgin.
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Affiliation(s)
- Paola G Ojeda
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, 3460000 Talca, Chile.
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomedicas, Universidad Autonoma de Chile, 3460000 Talca, Chile.
| | - David Ramírez
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, 3460000 Talca, Chile.
- Facultad de Ciencias de la Salud, Instituto de Ciencias Biomedicas, Universidad Autonoma de Chile, 3460000 Talca, Chile.
| | - Jans Alzate-Morales
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, 3460000 Talca, Chile.
| | - Julio Caballero
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, 3460000 Talca, Chile.
| | - Quentin Kaas
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - Wendy González
- Center for Bioinformatics and Molecular Simulations (CBSM), Universidad de Talca, 3460000 Talca, Chile.
- Millennium Nucleus of Ion Channels-Associated Diseases (MiNICAD), Universidad de Talca, 3460000 Talca, Chile.
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42
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Molecular characterization and expression analysis of CSαβ defensin genes from the scorpion Mesobuthus martensii. Biosci Rep 2017; 37:BSR20171282. [PMID: 29162666 PMCID: PMC6435467 DOI: 10.1042/bsr20171282] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 11/11/2017] [Accepted: 11/14/2017] [Indexed: 11/25/2022] Open
Abstract
Defensins are important components of innate host defence system against bacteria, fungi, parasites and viruses. Here, we predicted six potential defensin genes from the genome of the scorpion Mesobuthus martensii and then validated four genes from them via the combination of PCR and genomic sequence analysis. These four scorpion defensin genes share the same gene organization and structure of two exons and one phase-I intron with the GT-AG rule. Conserved motif and phylogenetic analysis showed that they belonged to the members of the invertebrate cysteine-stabilized α-helix/β-sheet motif defensin (CSαβ) defensin family. All these four CSαβ defensin genes have the expression feature of constitutive transcription (CON) by the whole scorpion infection model, promoter sequence analysis and dual luciferase assays. Further evolution and comparison analysis found that the invertebrate CSαβ defensin genes from most of arachnids and mollusks appear to share the expression pattern of CON, but those from insects and lower invertebrates (nematodes, annelids, cnidarians and sponges) seem to have identical inducible transcription (IND) after being challenged by microorganisms. Together, we identified four scorpion CSαβ defensin genes with the expression feature of CON, and characterized the diversified expression patterns of the invertebrate CSαβ defensin genes, which will shed insights into the evolution of the invertebrate CSαβ defensin genes and their expression patterns.
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43
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Li H, Xia Y. Recombinant production of the insecticidal scorpion toxin BjαIT in Escherichia coli. Protein Expr Purif 2017; 142:62-67. [PMID: 28988146 DOI: 10.1016/j.pep.2017.10.003] [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: 06/05/2017] [Revised: 09/26/2017] [Accepted: 10/01/2017] [Indexed: 01/28/2023]
Abstract
Scorpion long-chain insect neurotoxins have important potential application value in agricultural pest control. The difficulty of obtaining natural toxins is the major obstacle preventing analyses of their insecticidal activity against more agricultural insect pests. Here we cloned the insect neurotoxin BjαIT gene into the pET32 expression vector and expressed the resulting thioredoxin (Trx)-BjαIT fusion protein in Escherichia coli. Soluble Trx-BjαIT was expressed at a high level when induced at 18 °C with 0.1 mM isopropyl β-d-1-thiogalactopyranoside, and it was purified by Ni2+-nitriloacetic acid affinity chromatography. After cleaving the Trx tag with recombinant enterokinase, the digestion products were purified by CM Sepharose FF ion-exchange chromatography, and 1.5 mg of purified recombinant BjαIT (rBjαIT) was obtained from 100 ml of induced bacterial cells. Injecting rBjαIT induced obvious neurotoxic symptoms and led to death in locust (Locusta migratoria) larvae. Dietary toxicity was not observed in locusts. The results demonstrate that active rBjαIT could be obtained efficiently from an E. coli expression system, which is helpful for determining its insecticidal activity against agricultural insect pests.
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Affiliation(s)
- Hongbo Li
- The Key Laboratory of Research and Utilization of Ethnomedicinal Plant Resources of Hunan Province, College of Biological and Food Engineering, Huaihua University, Huaihua 418008, China; Genetic Engineering Research Center, College of Life Sciences, Chongqing University, Chongqing 400030, China
| | - Yuxian Xia
- Genetic Engineering Research Center, College of Life Sciences, Chongqing University, Chongqing 400030, China.
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44
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Luna-Ramirez K, Skaljac M, Grotmann J, Kirfel P, Vilcinskas A. Orally Delivered Scorpion Antimicrobial Peptides Exhibit Activity against Pea Aphid (Acyrthosiphon pisum) and Its Bacterial Symbionts. Toxins (Basel) 2017; 9:toxins9090261. [PMID: 28837113 PMCID: PMC5618194 DOI: 10.3390/toxins9090261] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 08/03/2017] [Accepted: 08/22/2017] [Indexed: 11/16/2022] Open
Abstract
Aphids are severe agricultural pests that damage crops by feeding on phloem sap and vectoring plant pathogens. Chemical insecticides provide an important aphid control strategy, but alternative and sustainable control measures are required to avoid rapidly emerging resistance, environmental contamination, and the risk to humans and beneficial organisms. Aphids are dependent on bacterial symbionts, which enable them to survive on phloem sap lacking essential nutrients, as well as conferring environmental stress tolerance and resistance to parasites. The evolution of aphids has been accompanied by the loss of many immunity-related genes, such as those encoding antibacterial peptides, which are prevalent in other insects, probably because any harm to the bacterial symbionts would inevitably affect the aphids themselves. This suggests that antimicrobial peptides (AMPs) could replace or at least complement conventional insecticides for aphid control. We fed the pea aphids (Acyrthosiphon pisum) with AMPs from the venom glands of scorpions. The AMPs reduced aphid survival, delayed their reproduction, displayed in vitro activity against aphid bacterial symbionts, and reduced the number of symbionts in vivo. Remarkably, we found that some of the scorpion AMPs compromised the aphid bacteriome, a specialized organ that harbours bacterial symbionts. Our data suggest that scorpion AMPs holds the potential to be developed as bio-insecticides, and are promising candidates for the engineering of aphid-resistant crops.
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Affiliation(s)
- Karen Luna-Ramirez
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Bioresources Project Group, Winchesterstrasse 2, 35394 Giessen, Germany.
| | - Marisa Skaljac
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Bioresources Project Group, Winchesterstrasse 2, 35394 Giessen, Germany.
| | - Jens Grotmann
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Bioresources Project Group, Winchesterstrasse 2, 35394 Giessen, Germany.
| | - Phillipp Kirfel
- Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Bioresources Project Group, Winchesterstrasse 2, 35394 Giessen, Germany.
| | - Andreas Vilcinskas
- Institute for Insect Biotechnology, Justus Liebig University of Giessen, Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany.
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45
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Melo MMA, Daniele-Silva A, Teixeira DG, Estrela AB, Melo KRT, Oliveira VS, Rocha HAO, Ferreira LDS, Pontes DL, Lima JPMS, Silva-Júnior AA, Barbosa EG, Carvalho E, Fernandes-Pedrosa MF. Structure and in vitro activities of a Copper II-chelating anionic peptide from the venom of the scorpion Tityus stigmurus. Peptides 2017; 94:91-98. [PMID: 28552408 DOI: 10.1016/j.peptides.2017.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 05/21/2017] [Accepted: 05/22/2017] [Indexed: 01/09/2023]
Abstract
Anionic Peptides are molecules rich in aspartic acid (Asp) and/or glutamic acid (Glu) residues in the primary structure. This work presents, for the first time, structural characterization and biological activity assays of an anionic peptide from the venom of the scorpion Tityus stigmurus, named TanP. The three-dimensional structure of TanP was obtained by computational modeling and refined by molecular dynamic (MD) simulations. Furthermore, we have performed circular dichroism (CD) analysis to predict TanP secondary structure, and UV-vis spectroscopy to evaluate its chelating activity. CD indicated predominance of random coil conformation in aqueous medium, as well as changes in structure depending on pH and temperature. TanP has chelating activity on copper ions, which modified the peptide's secondary structure. These results were corroborated by MD data. The molar ratio of binding (TanP:copper) depends on the concentration of peptide: at lower TanP concentration, the molar ratio was 1:5 (TanP:Cu2+), whereas in concentrated TanP solution, the molar ratio was 1:3 (TanP:Cu2+). TanP was not cytotoxic to non-neoplastic or cancer cell lines, and showed an ability to inhibit the in vitro release of nitric oxide by LPS-stimulated macrophages. Altogether, the results suggest TanP is a promising peptide for therapeutic application as a chelating agent.
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Affiliation(s)
- Menilla M A Melo
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, UFRN, Natal, RN, Brazil
| | - Alessandra Daniele-Silva
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Diego G Teixeira
- Laboratório de Sistemas Metabólicos, Centro de Biociências, UFRN, Natal, RN, Brazil
| | - Andréia B Estrela
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil
| | - Karolline R T Melo
- Laboratório de Biotecnologia de Polímeros Naturais, UFRN, Natal, RN, Brazil
| | | | - Hugo A O Rocha
- Laboratório de Biotecnologia de Polímeros Naturais, UFRN, Natal, RN, Brazil
| | | | - Daniel L Pontes
- Laboratório de Química de Coordenação e Polímeros, UFRN, Natal, RN, Brazil
| | - João P M S Lima
- Laboratório de Sistemas Metabólicos, Centro de Biociências, UFRN, Natal, RN, Brazil
| | - Arnóbio A Silva-Júnior
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, UFRN, Natal, RN, Brazil
| | - Euzebio G Barbosa
- Programa de Pós-Graduação em Ciências Farmacêuticas, UFRN, Natal, RN, Brazil; Laboratório de Química Farmacêutica, UFRN, Natal, RN, Brazil
| | - Eneas Carvalho
- Centro de Biotecnologia, Instituto Butantan, São Paulo, SP, Brazil
| | - Matheus F Fernandes-Pedrosa
- Laboratório de Tecnologia e Biotecnologia Farmacêutica, Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, UFRN, Natal, RN, Brazil.
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46
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Venom gland transcriptomic and venom proteomic analyses of the scorpion Megacormus gertschi Díaz-Najera, 1966 (Scorpiones: Euscorpiidae: Megacorminae). Toxicon 2017; 133:95-109. [DOI: 10.1016/j.toxicon.2017.05.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 04/20/2017] [Accepted: 05/01/2017] [Indexed: 12/31/2022]
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47
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Xie B, Huang Y, Baumann K, Fry BG, Shi Q. From Marine Venoms to Drugs: Efficiently Supported by a Combination of Transcriptomics and Proteomics. Mar Drugs 2017; 15:md15040103. [PMID: 28358320 PMCID: PMC5408249 DOI: 10.3390/md15040103] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/20/2017] [Accepted: 03/29/2017] [Indexed: 11/16/2022] Open
Abstract
The potential of marine natural products to become new drugs is vast; however, research is still in its infancy. The chemical and biological diversity of marine toxins is immeasurable and as such an extraordinary resource for the discovery of new drugs. With the rapid development of next-generation sequencing (NGS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS), it has been much easier and faster to identify more toxins and predict their functions with bioinformatics pipelines, which pave the way for novel drug developments. Here we provide an overview of related bioinformatics pipelines that have been supported by a combination of transcriptomics and proteomics for identification and function prediction of novel marine toxins.
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Affiliation(s)
- Bing Xie
- Venomics Research Group, BGI-Shenzhen, Shenzhen 518083, China.
| | - Yu Huang
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI, Shenzhen 518083, China.
| | - Kate Baumann
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Bryan Grieg Fry
- Venom Evolution Lab, School of Biological Sciences, University of Queensland, St. Lucia 4072, Australia.
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, BGI, Shenzhen 518083, China.
- BGI Shenzhen Academy of Marine Sciences, BGI Fisheries, BGI, Shenzhen 518083, China.
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48
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Shafee TMA, Lay FT, Phan TK, Anderson MA, Hulett MD. Convergent evolution of defensin sequence, structure and function. Cell Mol Life Sci 2017; 74:663-682. [PMID: 27557668 PMCID: PMC11107677 DOI: 10.1007/s00018-016-2344-5] [Citation(s) in RCA: 123] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 07/27/2016] [Accepted: 08/15/2016] [Indexed: 02/06/2023]
Abstract
Defensins are a well-characterised group of small, disulphide-rich, cationic peptides that are produced by essentially all eukaryotes and are highly diverse in their sequences and structures. Most display broad range antimicrobial activity at low micromolar concentrations, whereas others have other diverse roles, including cell signalling (e.g. immune cell recruitment, self/non-self-recognition), ion channel perturbation, toxic functions, and enzyme inhibition. The defensins consist of two superfamilies, each derived from an independent evolutionary origin, which have subsequently undergone extensive divergent evolution in their sequence, structure and function. Referred to as the cis- and trans-defensin superfamilies, they are classified based on their secondary structure orientation, cysteine motifs and disulphide bond connectivities, tertiary structure similarities and precursor gene sequence. The utility of displaying loops on a stable, compact, disulphide-rich core has been exploited by evolution on multiple occasions. The defensin superfamilies represent a case where the ensuing convergent evolution of sequence, structure and function has been particularly extreme. Here, we discuss the extent, causes and significance of these convergent features, drawing examples from across the eukaryotes.
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Affiliation(s)
- Thomas M A Shafee
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Fung T Lay
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Thanh Kha Phan
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia
| | - Marilyn A Anderson
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
| | - Mark D Hulett
- Department of Biochemistry and Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, VIC, 3086, Australia.
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Luna-Ramirez K, Tonk M, Rahnamaeian M, Vilcinskas A. Bioactivity of Natural and Engineered Antimicrobial Peptides from Venom of the Scorpions Urodacus yaschenkoi and U. manicatus. Toxins (Basel) 2017; 9:toxins9010022. [PMID: 28067810 PMCID: PMC5308254 DOI: 10.3390/toxins9010022] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2016] [Revised: 12/26/2016] [Accepted: 12/29/2016] [Indexed: 12/30/2022] Open
Abstract
The spread of multidrug-resistant human pathogens has drawn attention towards antimicrobial peptides (AMPs), which are major players in the innate immune systems of many organisms, including vertebrates, invertebrates, plants and microbes. Scorpion venom is an abundant source of novel and potent AMPs. Here, we investigated natural and engineered AMPs from the scorpions Urodacus yaschenkoi and U. manicatus to determine their antimicrobial spectra as well as their hemolytic/cytotoxic activity. None of the AMPs were active against fungi, but many of them were active at low concentrations (0.25–30 µM) against seven different bacteria. Hemolytic and cytotoxic activities were determined using pig erythrocytes and baby hamster kidney cells, respectively. The amino acid substitutions in the engineered AMPs did not inhibit cytotoxicity, but reduced hemolysis and therefore increased the therapeutic indices. The phylogenetic analysis of scorpion AMPs revealed they are closely related and the GXK motif is highly conserved. The engineered scorpion AMPs offer a promising alternative for the treatment of multidrug-resistant bacterial infections and could be modified further to reduce their hemolytic/cytotoxic activity.
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Affiliation(s)
- Karen Luna-Ramirez
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Winchester Strasse 2, D-35394 Giessen, Germany.
| | - Miray Tonk
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Winchester Strasse 2, D-35394 Giessen, Germany.
| | - Mohammad Rahnamaeian
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Winchester Strasse 2, D-35394 Giessen, Germany.
| | - Andreas Vilcinskas
- Fraunhofer Institute for Molecular Biology and Applied Ecology, Winchester Strasse 2, D-35394 Giessen, Germany.
- Institute for Insect Biotechnology, Justus Liebig University of Giessen, D-35392 Giessen, Germany.
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50
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Wang X, Gao B, Zhu S. Exon Shuffling and Origin of Scorpion Venom Biodiversity. Toxins (Basel) 2016; 9:toxins9010010. [PMID: 28035955 PMCID: PMC5308243 DOI: 10.3390/toxins9010010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 12/13/2016] [Accepted: 12/21/2016] [Indexed: 12/01/2022] Open
Abstract
Scorpion venom is a complex combinatorial library of peptides and proteins with multiple biological functions. A combination of transcriptomic and proteomic techniques has revealed its enormous molecular diversity, as identified by the presence of a large number of ion channel-targeted neurotoxins with different folds, membrane-active antimicrobial peptides, proteases, and protease inhibitors. Although the biodiversity of scorpion venom has long been known, how it arises remains unsolved. In this work, we analyzed the exon-intron structures of an array of scorpion venom protein-encoding genes and unexpectedly found that nearly all of these genes possess a phase-1 intron (one intron located between the first and second nucleotides of a codon) near the cleavage site of a signal sequence despite their mature peptides remarkably differ. This observation matches a theory of exon shuffling in the origin of new genes and suggests that recruitment of different folds into scorpion venom might be achieved via shuffling between body protein-coding genes and ancestral venom gland-specific genes that presumably contributed tissue-specific regulatory elements and secretory signal sequences.
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Affiliation(s)
- Xueli Wang
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Bin Gao
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Shunyi Zhu
- Group of Peptide Biology and Evolution, State Key Laboratory of Integrated Management of Pest Insects & Rodents, Institute of Zoology, Chinese Academy of Sciences, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
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