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Yap WY, Hwang JS. Is Proteolytic Cleavage Essential for the Enhanced Activity of Hydra Pore-Forming Toxin, HALT-4? Toxins (Basel) 2023; 15:396. [PMID: 37368697 DOI: 10.3390/toxins15060396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/07/2023] [Accepted: 06/11/2023] [Indexed: 06/29/2023] Open
Abstract
Hydra actinoporin-like toxin 4 (HALT-4) differs from other actinoporins due to its N-terminal propart that contains approximately 103 additional residues. Within this region, we identified five dibasic residues and assumed that, when cleaved, they could potentially exhibit HALT-4's cytolytic activity. We created five truncated versions of HALT-4 (tKK1, tKK2, tRK3, tKK4 and tKK5) to investigate the role of the N-terminal region and potential cleavage sites on the cytolytic activity of HALT-4. However, our results demonstrated that the propart-containing HALT-4 (proHALT-4), as well as the truncated versions tKK1 and tKK2, exhibited similar cytolytic activity against HeLa cells. In contrast, tRK3, tKK4 and tKK5 failed to kill HeLa cells, indicating that cleavage at the KK1 or KK2 sites did not enhance cytolytic activity but may instead facilitate the sorting of tKK1 and tKK2 to the regulated secretory pathway for eventual deposition in nematocysts. Moreover, RK3, KK4 and KK5 were unlikely to serve as proteolytic cleavage sites, as the amino acids between KK2 and RK3 are also crucial for pore formation.
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Affiliation(s)
- Wei Yuen Yap
- Department of Biological Sciences, School of Medical and Life Sciences, Sunway University, Bandar Sunway 47500, Malaysia
| | - Jung Shan Hwang
- Department of Medical Sciences, School of Medical and Life Sciences, Sunway University, Bandar Sunway 47500, Malaysia
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2
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Acontia, a Specialised Defensive Structure, Has Low Venom Complexity in Calliactis polypus. Toxins (Basel) 2023; 15:toxins15030218. [PMID: 36977109 PMCID: PMC10051995 DOI: 10.3390/toxins15030218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/14/2023] Open
Abstract
Phylum Cnidaria represents a unique group among venomous taxa, with its delivery system organised as individual organelles, known as nematocysts, heterogeneously distributed across morphological structures rather than packaged as a specialised organ. Acontia are packed with large nematocysts that are expelled from sea anemones during aggressive encounters with predatory species and are found in a limited number of species in the superfamily Metridioidea. Little is known about this specialised structure other than the commonly accepted hypothesis of its role in defence and a rudimentary understanding of its toxin content and activity. This study utilised previously published transcriptomic data and new proteomic analyses to expand this knowledge by identifying the venom profile of acontia in Calliactis polypus. Using mass spectrometry, we found limited toxin diversity in the proteome of acontia, with an abundance of a sodium channel toxin type I, and a novel toxin with two ShK-like domains. Additionally, genomic evidence suggests that the proposed novel toxin is ubiquitous across sea anemone lineages. Overall, the venom profile of acontia in Calliactis polypus and the novel toxin identified here provide the basis for future research to define the function of acontial toxins in sea anemones.
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3
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Palacios-Ortega J, García-Linares S, Rivera-de-Torre E, Heras-Márquez D, Gavilanes JG, Slotte JP, Martínez-Del-Pozo Á. Structural foundations of sticholysin functionality. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140696. [PMID: 34246789 DOI: 10.1016/j.bbapap.2021.140696] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 07/05/2021] [Accepted: 07/06/2021] [Indexed: 01/22/2023]
Abstract
Actinoporins constitute a family of α pore-forming toxins produced by sea anemones. The soluble fold of these proteins consists of a β-sandwich flanked by two α-helices. Actinoporins exert their activity by specifically recognizing sphingomyelin at their target membranes. Once there, they penetrate the membrane with their N-terminal α-helices, a process that leads to the formation of cation-selective pores. These pores kill the target cells by provoking an osmotic shock on them. In this review, we examine the role and relevance of the structural features of actinoporins, down to the residue level. We look at the specific amino acids that play significant roles in the function of actinoporins and their fold. Particular emphasis is given to those residues that display a high degree of conservation across the actinoporin sequences known to date. In light of the latest findings in the field, the membrane requirements for pore formation, the effect of lipid composition, and the process of pore formation are also discussed.
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Affiliation(s)
- Juan Palacios-Ortega
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain; Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland.
| | - Sara García-Linares
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - Esperanza Rivera-de-Torre
- Department of Biochemistry and Biotechnology, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Diego Heras-Márquez
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - José G Gavilanes
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
| | - J Peter Slotte
- Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Álvaro Martínez-Del-Pozo
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain
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4
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Toxin-like neuropeptides in the sea anemone Nematostella unravel recruitment from the nervous system to venom. Proc Natl Acad Sci U S A 2020; 117:27481-27492. [PMID: 33060291 DOI: 10.1073/pnas.2011120117] [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] [Indexed: 12/30/2022] Open
Abstract
The sea anemone Nematostella vectensis (Anthozoa, Cnidaria) is a powerful model for characterizing the evolution of genes functioning in venom and nervous systems. Although venom has evolved independently numerous times in animals, the evolutionary origin of many toxins remains unknown. In this work, we pinpoint an ancestral gene giving rise to a new toxin and functionally characterize both genes in the same species. Thus, we report a case of protein recruitment from the cnidarian nervous to venom system. The ShK-like1 peptide has a ShKT cysteine motif, is lethal for fish larvae and packaged into nematocysts, the cnidarian venom-producing stinging capsules. Thus, ShK-like1 is a toxic venom component. Its paralog, ShK-like2, is a neuropeptide localized to neurons and is involved in development. Both peptides exhibit similarities in their functional activities: They provoke contraction in Nematostella polyps and are toxic to fish. Because ShK-like2 but not ShK-like1 is conserved throughout sea anemone phylogeny, we conclude that the two paralogs originated due to a Nematostella-specific duplication of a ShK-like2 ancestor, a neuropeptide-encoding gene, followed by diversification and partial functional specialization. ShK-like2 is represented by two gene isoforms controlled by alternative promoters conferring regulatory flexibility throughout development. Additionally, we characterized the expression patterns of four other peptides with structural similarities to studied venom components and revealed their unexpected neuronal localization. Thus, we employed genomics, transcriptomics, and functional approaches to reveal one venom component, five neuropeptides with two different cysteine motifs, and an evolutionary pathway from nervous to venom system in Cnidaria.
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The Birth and Death of Toxins with Distinct Functions: A Case Study in the Sea Anemone Nematostella. Mol Biol Evol 2019; 36:2001-2012. [DOI: 10.1093/molbev/msz132] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Abstract
The cnidarian Nematostella vectensis has become an established lab model, providing unique opportunities for venom evolution research. The Nematostella venom system is multimodal: involving both nematocytes and ectodermal gland cells, which produce a toxin mixture whose composition changes throughout the life cycle. Additionally, their modes of interaction with predators and prey vary between eggs, larvae, and adults, which is likely shaped by the dynamics of the venom system.
Nv1 is a major component of adult venom, with activity against arthropods (through specific inhibition of sodium channel inactivation) and fish. Nv1 is encoded by a cluster of at least 12 nearly identical genes that were proposed to be undergoing concerted evolution. Surprisingly, we found that Nematostella venom includes several Nv1 paralogs escaping a pattern of general concerted evolution, despite belonging to the Nv1-like family. Here, we show two of these new toxins, Nv4 and Nv5, are lethal for zebrafish larvae but harmless to arthropods, unlike Nv1. Furthermore, unlike Nv1, the newly identified toxins are expressed in early life stages. Using transgenesis and immunostaining, we demonstrate that Nv4 and Nv5 are localized to ectodermal gland cells in larvae.
The evolution of Nv4 and Nv5 can be described either as neofunctionalization or as subfunctionalization. Additionally, the Nv1-like family includes several pseudogenes being an example of nonfunctionalization and venom evolution through birth-and-death mechanism. Our findings reveal the evolutionary history for a toxin radiation and point toward the ecological function of the novel toxins constituting a complex cnidarian venom.
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Babonis LS, DeBiasse MB, Francis WR, Christianson LM, Moss AG, Haddock SHD, Martindale MQ, Ryan JF. Integrating Embryonic Development and Evolutionary History to Characterize Tentacle-Specific Cell Types in a Ctenophore. Mol Biol Evol 2018; 35:2940-2956. [PMID: 30169705 PMCID: PMC6278862 DOI: 10.1093/molbev/msy171] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The origin of novel traits can promote expansion into new niches and drive speciation. Ctenophores (comb jellies) are unified by their possession of a novel cell type: the colloblast, an adhesive cell found only in the tentacles. Although colloblast-laden tentacles are fundamental for prey capture among ctenophores, some species have tentacles lacking colloblasts and others have lost their tentacles completely. We used transcriptomes from 36 ctenophore species to identify gene losses that occurred specifically in lineages lacking colloblasts and tentacles. We cross-referenced these colloblast- and tentacle-specific candidate genes with temporal RNA-Seq during embryogenesis in Mnemiopsis leidyi and found that both sets of candidates are preferentially expressed during tentacle morphogenesis. We also demonstrate significant upregulation of candidates from both data sets in the tentacle bulb of adults. Both sets of candidates were enriched for an N-terminal signal peptide and protein domains associated with secretion; among tentacle candidates we also identified orthologs of cnidarian toxin proteins, presenting tantalizing evidence that ctenophore tentacles may secrete toxins along with their adhesive. Finally, using cell lineage tracing, we demonstrate that colloblasts and neurons share a common progenitor, suggesting the evolution of colloblasts involved co-option of a neurosecretory gene regulatory network. Together these data offer an initial glimpse into the genetic architecture underlying ctenophore cell-type diversity.
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Affiliation(s)
- Leslie S Babonis
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL
| | - Melissa B DeBiasse
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL
| | - Warren R Francis
- Monterey Bay Aquarium Research Institute (MBARI), Moss Landing, CA
| | | | - Anthony G Moss
- Department of Biological Sciences, Auburn University, Auburn, AL
| | | | - Mark Q Martindale
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL
| | - Joseph F Ryan
- Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL
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7
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Leychenko E, Isaeva M, Tkacheva E, Zelepuga E, Kvetkina A, Guzev K, Monastyrnaya M, Kozlovskaya E. Multigene Family of Pore-Forming Toxins from Sea Anemone Heteractis crispa. Mar Drugs 2018; 16:E183. [PMID: 29794988 PMCID: PMC6025637 DOI: 10.3390/md16060183] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 05/21/2018] [Accepted: 05/22/2018] [Indexed: 11/23/2022] Open
Abstract
Sea anemones produce pore-forming toxins, actinoporins, which are interesting as tools for cytoplasmic membranes study, as well as being potential therapeutic agents for cancer therapy. This investigation is devoted to structural and functional study of the Heteractis crispa actinoporins diversity. Here, we described a multigene family consisting of 47 representatives expressed in the sea anemone tentacles as prepropeptide-coding transcripts. The phylogenetic analysis revealed that actinoporin clustering is consistent with the division of sea anemones into superfamilies and families. The transcriptomes of both H. crispa and Heteractis magnifica appear to contain a large repertoire of similar genes representing a rapid expansion of the actinoporin family due to gene duplication and sequence divergence. The presence of the most abundant specific group of actinoporins in H. crispa is the major difference between these species. The functional analysis of six recombinant actinoporins revealed that H. crispa actinoporin grouping was consistent with the different hemolytic activity of their representatives. According to molecular modeling data, we assume that the direction of the N-terminal dipole moment tightly reflects the actinoporins' ability to possess hemolytic activity.
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Affiliation(s)
- Elena Leychenko
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
- School of Natural Sciences, Far Eastern Federal University, Sukhanova Street 8, Vladivostok 690091, Russia.
| | - Marina Isaeva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
- School of Natural Sciences, Far Eastern Federal University, Sukhanova Street 8, Vladivostok 690091, Russia.
| | - Ekaterina Tkacheva
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Elena Zelepuga
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Aleksandra Kvetkina
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Konstantin Guzev
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Margarita Monastyrnaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
| | - Emma Kozlovskaya
- G.B. Elyakov Pacific Institute of Bioorganic Chemistry, Far Eastern Branch, Russian Academy of Sciences, 159, Pr. 100 let Vladivostoku, Vladivostok 690022, Russia.
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8
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Lewis Ames C, Macrander J. Evidence for an Alternative Mechanism of Toxin Production in the Box Jellyfish Alatina alata. Integr Comp Biol 2018; 56:973-988. [PMID: 27880678 DOI: 10.1093/icb/icw113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Cubozoans (box jellyfish) have a reputation as the most venomous animals on the planet. Herein, we provide a review of cubozoan prey capture and digestion informed by the scientific literature. Like all cnidarians, box jellyfish envenomation originates from structures secreted within nematocyte post-Golgi vesicles called nematocysts. When tentacles come in contact with prey or would-be predators, a cocktail of toxins is rapidly deployed from nematocysts via a long spiny tubule that serves to immobilize the target organism. The implication has long been that toxin peptides and proteins making up the venom within the nematocyst capsule are secreted directly by nematocytes during nematogenesis. However, our combined molecular and morphological analysis of the venomous box jellyfish Alatina alata suggests that gland cells with possible dual roles in secreting toxins and toxic-like enzymes are found in the gastric cirri. These putative gland cell assemblages might be functionally important internally (digestion of prey) as well as externally (envenomation) in cubozoans. Despite the absence of nematocysts in the gastric cirri of mature A. alata medusae, this area of the digestive system appears to be the region of the body where venom-implicated gene products are found in highest abundance, challenging the idea that in cnidarians venom is synthesized exclusively in, or nearby, nematocysts. In an effort to uncover evidence for a central area enriched in gland cells associated with the gastric cirri we provide a comparative description of the morphology of the digestive structures of A. alata and Carybdea box jellyfish species. Finally, we conduct a multi-faceted analysis of the gene ontology terms associated with venom-implicated genes expressed in the tentacle/pedalium and gastric cirri, with a particular emphasis on zinc metalloprotease homologs and genes encoding other bioactive proteins that are abundant in the A. alata transcriptome.
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Affiliation(s)
- Cheryl Lewis Ames
- *Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA; .,Biological Sciences Graduate Program, University of Maryland, College Park, MD 20742, USA
| | - Jason Macrander
- Department of Evolution, Ecology, and Organismal Biology, The Ohio State University, Columbus, OH 43215, USA
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9
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Columbus-Shenkar YY, Sachkova MY, Macrander J, Fridrich A, Modepalli V, Reitzel AM, Sunagar K, Moran Y. Dynamics of venom composition across a complex life cycle. eLife 2018; 7:35014. [PMID: 29424690 PMCID: PMC5832418 DOI: 10.7554/elife.35014] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 02/08/2018] [Indexed: 12/16/2022] Open
Abstract
Little is known about venom in young developmental stages of animals. The appearance of toxins and stinging cells during early embryonic stages in the sea anemone Nematostella vectensis suggests that venom is already expressed in eggs and larvae of this species. Here, we harness transcriptomic, biochemical and transgenic tools to study venom production dynamics in Nematostella. We find that venom composition and arsenal of toxin-producing cells change dramatically between developmental stages of this species. These findings can be explained by the vastly different interspecific interactions of each life stage, as individuals develop from a miniature non-feeding mobile planula to a larger sessile polyp that predates on other animals and interact differently with predators. Indeed, behavioral assays involving prey, predators and Nematostella are consistent with this hypothesis. Further, the results of this work suggest a much wider and dynamic venom landscape than initially appreciated in animals with a complex life cycle. Some animals produce a mixture of toxins, commonly known as venom, to protect themselves from predators and catch prey. Cnidarians – a group of animals that includes sea anemones, jellyfish and corals – have stinging cells on their tentacles that inject venom into the animals they touch. The sea anemone Nematostella goes through a complex life cycle. Nematostella start out life in eggs. They then become swimming larvae, barely visible to the naked eye, that do not feed. Adult Nematostella are cylindrical, stationary ‘polyps’ that are several inches long. They use tentacles at the end of their tube-like bodies to capture small aquatic animals. Sea anemones therefore change how they interact with predators and prey at different stages of their life. Most research on venomous animals focuses on adults, so until now it was not clear whether the venom changes along their maturation. Columbus-Shenkar, Sachkova et al. genetically modified Nematostella so that the cells that produce distinct venom components were labeled with different fluorescent markers. The composition of the venom could then be linked to how the anemones interacted with their fish and shrimp predators at each life stage. The results of the experiments showed that Nematostella mothers pass on a toxin to their eggs that makes them unpalatable to predators. Larvae then produce high levels of other toxins that allow them to incapacitate or kill potential predators. Adults have a different mix of toxins that likely help them capture prey. Venom is often studied because the compounds it contains have the potential to be developed into new drugs. The jellyfish and coral relatives of Nematostella may also produce different venoms at different life stages. This means that there are likely to be many toxins that we have not yet identified in these animals. As some jellyfish venoms are very active on humans and reef corals have a pivotal role in ocean ecology, further research into the venoms produced at different life stages could help us to understand and preserve marine ecosystems, as well as having medical benefits.
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Affiliation(s)
- Yaara Y Columbus-Shenkar
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maria Y Sachkova
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Jason Macrander
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Arie Fridrich
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Vengamanaidu Modepalli
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Adam M Reitzel
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, United States
| | - Kartik Sunagar
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.,Evolutionary Venomics Lab, Centre for Ecological Sciences, Indian Institute of Science, Bangalore, India
| | - Yehu Moran
- Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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10
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Pore-forming toxins in Cnidaria. Semin Cell Dev Biol 2017; 72:133-141. [DOI: 10.1016/j.semcdb.2017.07.026] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 07/14/2017] [Accepted: 07/20/2017] [Indexed: 01/05/2023]
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11
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Kim CH, Lee YJ, Go HJ, Oh HY, Lee TK, Park JB, Park NG. Defensin-neurotoxin dyad in a basally branching metazoan sea anemone. FEBS J 2017; 284:3320-3338. [DOI: 10.1111/febs.14194] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 07/27/2017] [Accepted: 08/07/2017] [Indexed: 11/26/2022]
Affiliation(s)
- Chan-Hee Kim
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
| | - Ye Jin Lee
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
| | - Hye-Jin Go
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
| | - Hye Young Oh
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
| | - Tae Kwan Lee
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
| | - Ji Been Park
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
| | - Nam Gyu Park
- Department of Biotechnology; College of Fisheries Sciences; Pukyong National University; Busan Korea
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12
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Madio B, Undheim EAB, King GF. Revisiting venom of the sea anemone Stichodactyla haddoni: Omics techniques reveal the complete toxin arsenal of a well-studied sea anemone genus. J Proteomics 2017; 166:83-92. [PMID: 28739511 DOI: 10.1016/j.jprot.2017.07.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 07/04/2017] [Accepted: 07/12/2017] [Indexed: 12/14/2022]
Abstract
More than a century of research on sea anemone venoms has shown that they contain a diversity of biologically active proteins and peptides. However, recent omics studies have revealed that much of the venom proteome remains unexplored. We used, for the first time, a combination of proteomic and transcriptomic techniques to obtain a holistic overview of the venom arsenal of the well-studied sea anemone Stichodactyla haddoni. A purely search-based approach to identify putative toxins in a transcriptome from tentacles regenerating after venom extraction identified 508 unique toxin-like transcripts grouped into 63 families. However, proteomic analysis of venom revealed that 52 of these toxin families are likely false positives. In contrast, the combination of transcriptomic and proteomic data enabled positive identification of 23 families of putative toxins, 12 of which have no homology known proteins or peptides. Our data highlight the importance of using proteomics of milked venom to correctly identify venom proteins/peptides, both known and novel, while minimizing false positive identifications from non-toxin homologues identified in transcriptomes of venom-producing tissues. This work lays the foundation for uncovering the role of individual toxins in sea anemone venom and how they contribute to the envenomation of prey, predators, and competitors. BIOLOGICAL SIGNIFICANCE Proteomic analysis of milked venom combined with analysis of a tentacle transcriptome revealed the full extent of the venom arsenal of the sea anemone Stichodactyla haddoni. This combined approach led to the discovery of 12 entirely new families of disulfide-rich peptides and proteins in a genus of anemones that have been studied for over a century.
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Affiliation(s)
- Bruno Madio
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, QLD 4072, Australia
| | - Eivind A B Undheim
- Centre for Advanced Imaging, University of Queensland, St. Lucia, QLD 4072, Australia.
| | - Glenn F King
- Institute for Molecular Bioscience, University of Queensland, St. Lucia, QLD 4072, Australia.
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13
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Huang C, Morlighem JÉR, Zhou H, Lima ÉP, Gomes PB, Cai J, Lou I, Pérez CD, Lee SM, Rádis-Baptista G. The Transcriptome of the Zoanthid Protopalythoa variabilis (Cnidaria, Anthozoa) Predicts a Basal Repertoire of Toxin-like and Venom-Auxiliary Polypeptides. Genome Biol Evol 2016; 8:3045-3064. [PMID: 27566758 PMCID: PMC5630949 DOI: 10.1093/gbe/evw204] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2016] [Indexed: 12/12/2022] Open
Abstract
Protopalythoa is a zoanthid that, together with thousands of predominantly marine species, such as hydra, jellyfish, and sea anemones, composes the oldest eumetazoan phylum, i.e., the Cnidaria. Some of these species, such as sea wasps and sea anemones, are highly venomous organisms that can produce deadly toxins for preying, for defense or for territorial disputes. Despite the fact that hundreds of organic and polypeptide toxins have been characterized from sea anemones and jellyfish, practically nothing is known about the toxin repertoire in zoanthids. Here, based on a transcriptome analysis of the zoanthid Protopalythoa variabilis, numerous predicted polypeptides with canonical venom protein features are identified. These polypeptides comprise putative proteins from different toxin families: neurotoxic peptides, hemostatic and hemorrhagic toxins, membrane-active (pore-forming) proteins, protease inhibitors, mixed-function venom enzymes, and venom auxiliary proteins. The synthesis and functional analysis of two of these predicted toxin products, one related to the ShK/Aurelin family and the other to a recently discovered anthozoan toxin, displayed potent in vivo neurotoxicity that impaired swimming in larval zebrafish. Altogether, the complex array of venom-related transcripts that are identified in P. variabilis, some of which are first reported in Cnidaria, provides novel insight into the toxin distribution among species and might contribute to the understanding of composition and evolution of venom polypeptides in toxiferous animals.
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Affiliation(s)
- Chen Huang
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Jean-Étienne Rl Morlighem
- Northeast Biotechnology Network (RENORBIO), Post-graduation program in Biotechnology, Federal University of Ceará, Fortaleza, Brazil Laboratory of Biochemistry and Biotechnology, Institute for Marine Sciences, Federal University of Ceará, Fortaleza, Brazil
| | - Hefeng Zhou
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Érica P Lima
- Centro Acadêmico de Vitoria, Universidade Federal de Pernambuco, Vitória de Santo Antão, Brazil
| | - Paula B Gomes
- Departamento de Biologia, Universidade Federal Rural de Pernambuco, Recife, Brazil
| | - Jing Cai
- Faculty of Science and Technology, Department of Civil and Environmental Engineering, University of Macau, Macau, China
| | - Inchio Lou
- Faculty of Science and Technology, Department of Civil and Environmental Engineering, University of Macau, Macau, China
| | - Carlos D Pérez
- Centro Acadêmico de Vitoria, Universidade Federal de Pernambuco, Vitória de Santo Antão, Brazil
| | - Simon Ming Lee
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macau, China
| | - Gandhi Rádis-Baptista
- Laboratory of Biochemistry and Biotechnology, Institute for Marine Sciences, Federal University of Ceará, Fortaleza, Brazil
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14
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Valle A, Alvarado-Mesén J, Lanio M, Álvarez C, Barbosa J, Pazos I. The multigene families of actinoporins (part I): Isoforms and genetic structure. Toxicon 2015; 103:176-87. [DOI: 10.1016/j.toxicon.2015.06.028] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 05/31/2015] [Accepted: 06/23/2015] [Indexed: 11/24/2022]
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15
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Glasser E, Rachamim T, Aharonovich D, Sher D. Hydra actinoporin-like toxin-1, an unusual hemolysin from the nematocyst venom of Hydra magnipapillata which belongs to an extended gene family. Toxicon 2014; 91:103-13. [PMID: 24768765 DOI: 10.1016/j.toxicon.2014.04.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Revised: 03/23/2014] [Accepted: 04/08/2014] [Indexed: 01/09/2023]
Abstract
Cnidarians rely on their nematocysts and the venom injected through these unique weaponry systems to catch prey and protect themselves from predators. The development and physiology of the nematocysts of Hydra magnipapillata, a classic model organism, have been intensively studied, yet the composition and biochemical activity of their venom components are mostly unknown. Here, we show that hydra actinoporin-like toxins (HALTs), which have previously been associated with Hydra nematocysts, belong to a multigene family comprising six genes, which have diverged from a single common ancestor. All six genes are expressed in a population of Hydra magnipapillata. When expressed recombinantly, HALT-1 (Δ-HYTX-Hma1a), an actinoporin-like protein found in the stenoteles (the main penetrating nematocysts used in prey capture), reveals hemolytic activity, albeit about two-thirds lower than that of the anemone actinoporin equinatoxin II (EqTII, Δ-AITX-Aeq1a). HALT-1 also differs from EqTII in the size of its pores, and likely does not utilize sphingomyelin as a membrane receptor. We describe features of the HALT-1 sequence which may contribute to this difference in activity, and speculate on the role of this unusual family of pore-forming toxins in the ecology of Hydra.
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Affiliation(s)
- Eliezra Glasser
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 31905 Haifa, Israel
| | - Tamar Rachamim
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 31905 Haifa, Israel
| | - Dikla Aharonovich
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 31905 Haifa, Israel
| | - Daniel Sher
- Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 31905 Haifa, Israel.
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16
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Brinkman DL, Konstantakopoulos N, McInerney BV, Mulvenna J, Seymour JE, Isbister GK, Hodgson WC. Chironex fleckeri (box jellyfish) venom proteins: expansion of a cnidarian toxin family that elicits variable cytolytic and cardiovascular effects. J Biol Chem 2014; 289:4798-812. [PMID: 24403082 DOI: 10.1074/jbc.m113.534149] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The box jellyfish Chironex fleckeri produces extremely potent and rapid-acting venom that is harmful to humans and lethal to prey. Here, we describe the characterization of two C. fleckeri venom proteins, CfTX-A (∼40 kDa) and CfTX-B (∼42 kDa), which were isolated from C. fleckeri venom using size exclusion chromatography and cation exchange chromatography. Full-length cDNA sequences encoding CfTX-A and -B and a third putative toxin, CfTX-Bt, were subsequently retrieved from a C. fleckeri tentacle cDNA library. Bioinformatic analyses revealed that the new toxins belong to a small family of potent cnidarian pore-forming toxins that includes two other C. fleckeri toxins, CfTX-1 and CfTX-2. Phylogenetic inferences from amino acid sequences of the toxin family grouped CfTX-A, -B, and -Bt in a separate clade from CfTX-1 and -2, suggesting that the C. fleckeri toxins have diversified structurally and functionally during evolution. Comparative bioactivity assays revealed that CfTX-1/2 (25 μg kg(-1)) caused profound effects on the cardiovascular system of anesthetized rats, whereas CfTX-A/B elicited only minor effects at the same dose. Conversely, the hemolytic activity of CfTX-A/B (HU50 = 5 ng ml(-1)) was at least 30 times greater than that of CfTX-1/2. Structural homology between the cubozoan toxins and insecticidal three-domain Cry toxins (δ-endotoxins) suggests that the toxins have a similar pore-forming mechanism of action involving α-helices of the N-terminal domain, whereas structural diversification among toxin members may modulate target specificity. Expansion of the cnidarian toxin family therefore provides new insights into the evolutionary diversification of box jellyfish toxins from a structural and functional perspective.
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Affiliation(s)
- Diane L Brinkman
- From the Australian Institute of Marine Science, P.M.B. No 3, Townsville Mail Centre, Townsville, Queensland 4810, Australia
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17
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Abstract
Membrane Attack Complex/Perforin (MACPF) and Cholesterol-Dependent Cytolysins (CDC) form the MACPF/CDC superfamily of important effector proteins widespread in nature. MACPFs and CDCs were discovered separately with no sequence similarity at that stage being apparent between the two protein families such that they were not, until recently, considered evolutionary related. The breakthrough showing they are came with recent structural work that also shed light on the molecular mechanism of action of various MACPF proteins. Similarity in structural properties and conserved functional features indicate that both protein families have the same evolutionary origin. We will describe the distribution of MACPF/CDC proteins in nature and discuss briefly their similarity and functional role in different biological processes.
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Affiliation(s)
- Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Hajdrihova 19, 1000, Ljubljana, Slovenia,
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Evidence of accelerated evolution and ectodermal-specific expression of presumptive BDS toxin cDNAs from Anemonia viridis. Mar Drugs 2013; 11:4213-31. [PMID: 24177670 PMCID: PMC3853724 DOI: 10.3390/md11114213] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 09/10/2013] [Accepted: 09/13/2013] [Indexed: 12/14/2022] Open
Abstract
Anemonia viridis is a widespread and extensively studied Mediterranean species of sea anemone from which a large number of polypeptide toxins, such as blood depressing substances (BDS) peptides, have been isolated. The first members of this class, BDS-1 and BDS-2, are polypeptides belonging to the β-defensin fold family and were initially described for their antihypertensive and antiviral activities. BDS-1 and BDS-2 are 43 amino acid peptides characterised by three disulfide bonds that act as neurotoxins affecting Kv3.1, Kv3.2 and Kv3.4 channel gating kinetics. In addition, BDS-1 inactivates the Nav1.7 and Nav1.3 channels. The development of a large dataset of A. viridis expressed sequence tags (ESTs) and the identification of 13 putative BDS-like cDNA sequences has attracted interest, especially as scientific and diagnostic tools. A comparison of BDS cDNA sequences showed that the untranslated regions are more conserved than the protein-coding regions. Moreover, the KA/KS ratios calculated for all pairwise comparisons showed values greater than 1, suggesting mechanisms of accelerated evolution. The structures of the BDS homologs were predicted by molecular modelling. All toxins possess similar 3D structures that consist of a triple-stranded antiparallel β-sheet and an additional small antiparallel β-sheet located downstream of the cleavage/maturation site; however, the orientation of the triple-stranded β-sheet appears to differ among the toxins. To characterise the spatial expression profile of the putative BDS cDNA sequences, tissue-specific cDNA libraries, enriched for BDS transcripts, were constructed. In addition, the proper amplification of ectodermal or endodermal markers ensured the tissue specificity of each library. Sequencing randomly selected clones from each library revealed ectodermal-specific expression of ten BDS transcripts, while transcripts of BDS-8, BDS-13, BDS-14 and BDS-15 failed to be retrieved, likely due to under-representation in our cDNA libraries. The calculation of the relative abundance of BDS transcripts in the cDNA libraries revealed that BDS-1, BDS-3, BDS-4, BDS-5 and BDS-6 are the most represented transcripts.
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Orts DJB, Moran Y, Cologna CT, Peigneur S, Madio B, Praher D, Quinton L, De Pauw E, Bicudo JEPW, Tytgat J, de Freitas JC. BcsTx3 is a founder of a novel sea anemone toxin family of potassium channel blocker. FEBS J 2013; 280:4839-52. [PMID: 23895459 DOI: 10.1111/febs.12456] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 07/17/2013] [Accepted: 07/24/2013] [Indexed: 12/29/2022]
Abstract
Sea anemone venoms have become a rich source of peptide toxins which are invaluable tools for studying the structure and functions of ion channels. In this work, BcsTx3, a toxin found in the venom of a Bunodosoma caissarum (population captured at the Saint Peter and Saint Paul Archipelago, Brazil) was purified and biochemically and pharmacologically characterized. The pharmacological effects were studied on 12 different subtypes of voltage-gated potassium channels (K(V)1.1-K(V)1.6; K(V)2.1; K(V)3.1; K(V)4.2; K(V)4.3; hERG and Shaker IR) and three cloned voltage-gated sodium channel isoforms (Na(V)1.2, Na(V)1.4 and BgNa(V)1.1) expressed in Xenopus laevis oocytes. BcsTx3 shows a high affinity for Drosophila Shaker IR channels over rKv1.2, hKv1.3 and rKv1.6, and is not active on NaV channels. Biochemical characterization reveals that BcsTx3 is a 50 amino acid peptide crosslinked by four disulfide bridges, and sequence comparison allowed BcsTx3 to be classified as a novel type of sea anemone toxin acting on K(V) channels. Moreover, putative toxins homologous to BcsTx3 from two additional actiniarian species suggest an ancient origin of this newly discovered toxin family.
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Affiliation(s)
- Diego J B Orts
- Department of Physiology, Institute of Biosciences, University of São Paulo, Brazil
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20
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Protease inhibitors from marine venomous animals and their counterparts in terrestrial venomous animals. Mar Drugs 2013; 11:2069-112. [PMID: 23771044 PMCID: PMC3721222 DOI: 10.3390/md11062069] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 05/28/2013] [Accepted: 05/30/2013] [Indexed: 01/04/2023] Open
Abstract
The Kunitz-type protease inhibitors are the best-characterized family of serine protease inhibitors, probably due to their abundance in several organisms. These inhibitors consist of a chain of ~60 amino acid residues stabilized by three disulfide bridges, and was first observed in the bovine pancreatic trypsin inhibitor (BPTI)-like protease inhibitors, which strongly inhibit trypsin and chymotrypsin. In this review we present the protease inhibitors (PIs) described to date from marine venomous animals, such as from sea anemone extracts and Conus venom, as well as their counterparts in terrestrial venomous animals, such as snakes, scorpions, spiders, Anurans, and Hymenopterans. More emphasis was given to the Kunitz-type inhibitors, once they are found in all these organisms. Their biological sources, specificity against different proteases, and other molecular blanks (being also K+ channel blockers) are presented, followed by their molecular diversity. Whereas sea anemone, snakes and other venomous animals present mainly Kunitz-type inhibitors, PIs from Anurans present the major variety in structure length and number of Cys residues, with at least six distinguishable classes. A representative alignment of PIs from these venomous animals shows that, despite eventual differences in Cys assignment, the key-residues for the protease inhibitory activity in all of them occupy similar positions in primary sequence. The key-residues for the K+ channel blocking activity was also compared.
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21
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AdE-1, a new inotropic Na+ channel toxin from Aiptasia diaphana, is similar to, yet distinct from, known anemone Na+ channel toxins. Biochem J 2013; 451:81-90. [DOI: 10.1042/bj20121623] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Heart failure is one of the most prevalent causes of death in the western world. Sea anemone contains a myriad of short peptide neurotoxins affecting many pharmacological targets, several of which possess cardiotonic activity. In the present study we describe the isolation and characterization of AdE-1 (ion channel modifier), a novel cardiotonic peptide from the sea anemone Aiptasia diaphana, which differs from other cnidarian toxins. Although AdE-1 has the same cysteine residue arrangement as sea anemone type 1 and 2 Na+ channel toxins, its sequence contains many substitutions in conserved and essential sites and its overall homology to other toxins identified to date is low (<36%). Physiologically, AdE-1 increases the amplitude of cardiomyocyte contraction and slows the late phase of the twitch relaxation velocity with no induction of spontaneous twitching. It increases action potential duration of cardiomyocytes with no effect on its threshold and on the cell's resting potential. Similar to other sea anemone Na+ channel toxins such as Av2 (Anemonia viridis toxin II), AdE-1 markedly inhibits Na+ current inactivation with no significant effect on current activation, suggesting a similar mechanism of action. However, its effects on twitch relaxation velocity, action potential amplitude and on the time to peak suggest that this novel toxin affects cardiomyocyte function via a more complex mechanism. Additionally, Av2's characteristic delayed and early after-depolarizations were not observed. Despite its structural differences, AdE-1 physiologic effectiveness is comparable with Av2 with a similar ED50 value to blowfly larvae. This finding raises questions regarding the extent of the universality of structure–function in sea anemone Na+ channel toxins.
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22
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Urbarova I, Karlsen BO, Okkenhaug S, Seternes OM, Johansen SD, Emblem Å. Digital marine bioprospecting: mining new neurotoxin drug candidates from the transcriptomes of cold-water sea anemones. Mar Drugs 2012; 10:2265-2279. [PMID: 23170083 PMCID: PMC3497022 DOI: 10.3390/md10102265] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Revised: 10/08/2012] [Accepted: 10/10/2012] [Indexed: 11/16/2022] Open
Abstract
Marine bioprospecting is the search for new marine bioactive compounds and large-scale screening in extracts represents the traditional approach. Here, we report an alternative complementary protocol, called digital marine bioprospecting, based on deep sequencing of transcriptomes. We sequenced the transcriptomes from the adult polyp stage of two cold-water sea anemones, Bolocera tuediae and Hormathia digitata. We generated approximately 1.1 million quality-filtered sequencing reads by 454 pyrosequencing, which were assembled into approximately 120,000 contigs and 220,000 single reads. Based on annotation and gene ontology analysis we profiled the expressed mRNA transcripts according to known biological processes. As a proof-of-concept we identified polypeptide toxins with a potential blocking activity on sodium and potassium voltage-gated channels from digital transcriptome libraries.
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Affiliation(s)
- Ilona Urbarova
- RNA and Transcriptomics Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, N9037 Tromsø, Norway; (I.U.); (B.O.K.); (S.O.); (A.E.)
| | - Bård Ove Karlsen
- RNA and Transcriptomics Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, N9037 Tromsø, Norway; (I.U.); (B.O.K.); (S.O.); (A.E.)
| | - Siri Okkenhaug
- RNA and Transcriptomics Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, N9037 Tromsø, Norway; (I.U.); (B.O.K.); (S.O.); (A.E.)
| | - Ole Morten Seternes
- Pharmacology Group, Department of Pharmacy, Faculty of Health Sciences, University of Tromsø, N9037 Tromsø, Norway;
| | - Steinar D. Johansen
- RNA and Transcriptomics Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, N9037 Tromsø, Norway; (I.U.); (B.O.K.); (S.O.); (A.E.)
- Marine Genomics Group, Faculty of Biosciences and Aquaculture, University of Nordland, N8049 Bodø, Norway
| | - Åse Emblem
- RNA and Transcriptomics Group, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, N9037 Tromsø, Norway; (I.U.); (B.O.K.); (S.O.); (A.E.)
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23
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Frazão B, Vasconcelos V, Antunes A. Sea anemone (Cnidaria, Anthozoa, Actiniaria) toxins: an overview. Mar Drugs 2012; 10:1812-1851. [PMID: 23015776 PMCID: PMC3447340 DOI: 10.3390/md10081812] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2012] [Revised: 07/09/2012] [Accepted: 07/25/2012] [Indexed: 01/20/2023] Open
Abstract
The Cnidaria phylum includes organisms that are among the most venomous animals. The Anthozoa class includes sea anemones, hard corals, soft corals and sea pens. The composition of cnidarian venoms is not known in detail, but they appear to contain a variety of compounds. Currently around 250 of those compounds have been identified (peptides, proteins, enzymes and proteinase inhibitors) and non-proteinaceous substances (purines, quaternary ammonium compounds, biogenic amines and betaines), but very few genes encoding toxins were described and only a few related protein three-dimensional structures are available. Toxins are used for prey acquisition, but also to deter potential predators (with neurotoxicity and cardiotoxicity effects) and even to fight territorial disputes. Cnidaria toxins have been identified on the nematocysts located on the tentacles, acrorhagi and acontia, and in the mucous coat that covers the animal body. Sea anemone toxins comprise mainly proteins and peptides that are cytolytic or neurotoxic with its potency varying with the structure and site of action and are efficient in targeting different animals, such as insects, crustaceans and vertebrates. Sea anemones toxins include voltage-gated Na⁺ and K⁺ channels toxins, acid-sensing ion channel toxins, Cytolysins, toxins with Kunitz-type protease inhibitors activity and toxins with Phospholipase A2 activity. In this review we assessed the phylogentic relationships of sea anemone toxins, characterized such toxins, the genes encoding them and the toxins three-dimensional structures, further providing a state-of-the-art description of the procedures involved in the isolation and purification of bioactive toxins.
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Affiliation(s)
- Bárbara Frazão
- CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 177, 4050-123 Porto, Portugal; (B.F.); (V.V.)
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Vitor Vasconcelos
- CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 177, 4050-123 Porto, Portugal; (B.F.); (V.V.)
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
| | - Agostinho Antunes
- CIMAR/CIIMAR, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Rua dos Bragas 177, 4050-123 Porto, Portugal; (B.F.); (V.V.)
- Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto, Portugal
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24
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Screening and cDNA cloning of Kv1 potassium channel toxins in sea anemones. Mar Drugs 2010; 8:2893-905. [PMID: 21339955 PMCID: PMC3039155 DOI: 10.3390/md8122893] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2010] [Revised: 11/19/2010] [Accepted: 12/01/2010] [Indexed: 12/12/2022] Open
Abstract
When 21 species of sea anemones were screened for Kv1 potassium channel toxins by competitive inhibition of the binding of 125I-α-dendrotoxin to rat synaptosomal membranes, 11 species (two species of Actiniidae, one species of Hormathiidae, five species of Stichodactylidae and three species of Thalassianthidae) were found to be positive. Furthermore, full-length cDNAs encoding type 1 potassium channel toxins from three species of Stichodactylidae and three species of Thalassianthidae were cloned by a combination of RT-PCR, 3′RACE and 5′RACE. The precursors of these six toxins are commonly composed of signal peptide, propart and mature peptide portions. As for the mature peptide (35 amino acid residues), the six toxins share more than 90% sequence identities with one another and with κ1.3-SHTX-She1a (Shk) from Stichodactyla helianthus but only 34–63% identities with the other type 1 potassium channel toxins.
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25
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Maeda M, Honma T, Shiomi K. Isolation and cDNA cloning of type 2 sodium channel peptide toxins from three species of sea anemones (Cryptodendrum adhaesivum, Heterodactyla hemprichii and Thalassianthus aster) belonging to the family Thalassianthidae. Comp Biochem Physiol B Biochem Mol Biol 2010; 157:389-93. [PMID: 20817118 DOI: 10.1016/j.cbpb.2010.08.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2009] [Revised: 08/29/2010] [Accepted: 08/29/2010] [Indexed: 10/19/2022]
Abstract
The crude extracts from three species of sea anemones (Cryptodendrum adhaesivum, Heterodactyla hemprichii and Thalassianthus aster) belonging to the family Thalassianthidae exhibited potent lethality to freshwater crabs (Potamon dehaani). Regardless of the species, high and low molecular weight toxins were found in gel filtration of the crude extract. Following reverse-phase HPLC of the low molecular weight toxin fractions, one toxin (δ-TLTX-Ca1a), two toxins (δ-TLTX-Hh1a and c) and one toxin (δ-TLTX-Ta1a) were isolated from C. adhaesivum, H. hemprichii and T. aster, respectively. Based on the determined N-terminal amino acid sequences, the cDNAs encoding δ-TLTX-Ca1a, δ-TLTX-Hh1x (not assignable to either δ-TLTX-Hh1a or δ-TLTX-Hh1c) and δ-TLTX-Ta1a were successfully cloned by both 3' and 5' RACE methods. In common with the three toxins, the precursor is composed of a signal peptide (19 amino acid residues), propart (16 residues) and mature portion (49 residues), similar to those of many sea anemone peptide toxins. The deduced amino acid sequences showed that the three toxins are closely similar to one another, being all new members of the type 2 sea anemone sodium channel peptide toxin family.
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Affiliation(s)
- Mikiko Maeda
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo, Japan
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26
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27
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Moran Y, Weinberger H, Lazarus N, Gur M, Kahn R, Gordon D, Gurevitz M. Fusion and retrotransposition events in the evolution of the sea anemone Anemonia viridis neurotoxin genes. J Mol Evol 2009; 69:115-24. [PMID: 19609479 DOI: 10.1007/s00239-009-9258-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 06/03/2009] [Accepted: 06/10/2009] [Indexed: 12/01/2022]
Abstract
Sea anemones are sessile predators that use a variety of toxins to paralyze prey and foe. Among these toxins, Types I, II and III are short peptides that affect voltage-gated sodium channels. Anemonia viridis is the only sea anemone species that produces both Types I and III neurotoxin. Although the two toxin types are unrelated in sequence and three-dimensional structure, cloning and comparative analysis of their loci revealed a highly similar sequence at the 5' region, which encodes a signal peptide. This similarity was likely generated by gene fusion and could be advantageous in transcript stability and intracellular trafficking and secretion. In addition, these analyses identified the processed pseudogenes of the two gene families in the genome of A. viridis, probably resulting from retrotransposition events. As presence of processed pseudogenes in the genome requires transcription in germ-line cells, we analyzed oocyte-rich ovaries and found that indeed they contain Types I and III transcripts. This result raises questions regarding the role of toxin transcripts in these tissues. Overall, the retrotransposition and gene fusion events suggest that the genes of both Types I and III neurotoxins evolved in a similar fashion and share a partial common ancestry.
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Affiliation(s)
- Yehu Moran
- Department of Plant Sciences, Tel-Aviv University, Ramat-Aviv, Israel.
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28
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Moran Y, Gordon D, Gurevitz M. Sea anemone toxins affecting voltage-gated sodium channels--molecular and evolutionary features. Toxicon 2009; 54:1089-101. [PMID: 19268682 DOI: 10.1016/j.toxicon.2009.02.028] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The venom of sea anemones is rich in low molecular weight proteinaceous neurotoxins that vary greatly in structure, site of action, and phyletic (insect, crustacean or vertebrate) preference. This toxic versatility likely contributes to the ability of these sessile animals to inhabit marine environments co-habited by a variety of mobile predators. Among these toxins, those that show prominent activity at voltage-gated sodium channels and are critical in predation and defense, have been extensively studied for more than three decades. These studies initially focused on the discovery of new toxins, determination of their covalent and folded structures, understanding of their mechanisms of action on different sodium channels, and identification of the primary sites of interaction of the toxins with their channel receptors. The channel binding site for Type I and the structurally unrelated Type III sea anemone toxins was identified as neurotoxin receptor site 3, a site previously shown to be targeted by scorpion alpha-toxins. The bioactive surfaces of toxin representatives from these two sea anemone types have been characterized by mutagenesis. These analyses pointed to heterogeneity of receptor site 3 at various sodium channels. A turning point in evolutionary studies of sea anemone toxins was the recent release of the genome sequence of Nematostella vectensis, which enabled analysis of the genomic organization of the corresponding genes. This analysis demonstrated that Type I toxins in Nematostella and other species are encoded by gene families and suggested that these genes developed by concerted evolution. The current review provides a brief historical description of the discovery and characterization of sea anemone toxins that affect voltage-gated sodium channels and delineates recent advances in the study of their structure-activity relationship and evolution.
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Affiliation(s)
- Yehu Moran
- Department of Plant Sciences, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel.
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Honma T, Kawahata S, Ishida M, Nagai H, Nagashima Y, Shiomi K. Novel peptide toxins from the sea anemone Stichodactyla haddoni. Peptides 2008; 29:536-44. [PMID: 18243416 DOI: 10.1016/j.peptides.2007.12.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2007] [Revised: 12/13/2007] [Accepted: 12/14/2007] [Indexed: 11/24/2022]
Abstract
Four peptide toxins, SHTX I-III with crab-paralyzing activity and SHTX IV with crab lethality, were isolated from the sea anemone Stichodactyla haddoni and their primary structures elucidated by protein sequencing and cDNA cloning. SHTX I (new toxin, 28 residues), II (analogue of SHTX I, 28 residues) and III (Kunitz-type protease inhibitor, 62 residues) are potassium channel toxins and SHTX IV (48 residues) is a member of the type 2 sea anemone sodium channel toxins. The precursor protein of SHTX IV is composed of a signal peptide, propart and mature peptide, while the propart is missing in that of SHTX III. In addition to these four toxins, an epidermal growth factor-like peptide was detected in S. haddoni by RT-PCR.
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Affiliation(s)
- Tomohiro Honma
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Tokyo 108-8477, Japan
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30
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Hwang JS, Ohyanagi H, Hayakawa S, Osato N, Nishimiya-Fujisawa C, Ikeo K, David CN, Fujisawa T, Gojobori T. The evolutionary emergence of cell type-specific genes inferred from the gene expression analysis of Hydra. Proc Natl Acad Sci U S A 2007; 104:14735-40. [PMID: 17766437 PMCID: PMC1963347 DOI: 10.1073/pnas.0703331104] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell lineages of cnidarians including Hydra represent the fundamental cell types of metazoans and provides us a unique opportunity to study the evolutionary diversification of cell type in the animal kingdom. Hydra contains epithelial cells as well as a multipotent interstitial cell (I-cell) that gives rise to nematocytes, nerve cells, gland cells, and germ-line cells. We used cDNA microarrays to identify cell type-specific genes by comparing gene expression in normal Hydra with animals lacking the I-cell lineage, so-called epithelial Hydra. We then performed in situ hybridization to localize expression to specific cell types. Eighty-six genes were shown to be expressed in specific cell types of the I-cell lineage. An additional 29 genes were expressed in epithelial cells and were down-regulated in epithelial animals lacking I-cells. Based on the above information, we constructed a database (http://hydra.lab.nig.ac.jp/hydra/), which describes the expression patterns of cell type-specific genes in Hydra. Most genes expressed specifically in either I-cells or epithelial cells have homologues in higher metazoans. By comparison, most nematocyte-specific genes and approximately half of the gland cell- and nerve cell-specific genes are unique to the cnidarian lineage. Because nematocytes, gland cells, and nerve cells appeared along with the emergence of cnidarians, this suggests that lineage-specific genes arose in cnidarians in conjunction with the evolution of new cell types required by the cnidarians.
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Affiliation(s)
| | - Hajime Ohyanagi
- *Center for Information Biology and DNA Data Bank of Japan
- Tsukuba Division, Mitsubishi Space Software Co., Ltd., 1-6-1 Takezono, Tsukuba, Ibaraki 305-0032, Japan; and
| | - Shiho Hayakawa
- *Center for Information Biology and DNA Data Bank of Japan
| | - Naoki Osato
- *Center for Information Biology and DNA Data Bank of Japan
| | - Chiemi Nishimiya-Fujisawa
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Shizuoka 411-8540 Japan
| | - Kazuho Ikeo
- *Center for Information Biology and DNA Data Bank of Japan
| | - Charles N. David
- Department Biologie II, Ludwig Maximilians University, Grosshadernerstrasse 2, D-82152 Planegg/Martinsried, Germany
| | - Toshitaka Fujisawa
- Department of Developmental Genetics, National Institute of Genetics, Mishima, Shizuoka 411-8540 Japan
| | - Takashi Gojobori
- *Center for Information Biology and DNA Data Bank of Japan
- To whom correspondence should be addressed. E-mail:
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Hasegawa Y, Honma T, Nagai H, Ishida M, Nagashima Y, Shiomi K. Isolation and cDNA cloning of a potassium channel peptide toxin from the sea anemone Anemonia erythraea. Toxicon 2006; 48:536-42. [PMID: 16905168 DOI: 10.1016/j.toxicon.2006.07.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 06/26/2006] [Accepted: 07/03/2006] [Indexed: 12/01/2022]
Abstract
A potassium channel peptide toxin (AETX K) was isolated from the sea anemone Anemonia erythraea by gel filtration on Sephadex G-50, reverse-phase HPLC on TSKgel ODS-120T and anion-exchange HPLC on Mono Q. AETX K inhibited the binding of (125)I-alpha-dendrotoxin to rat synaptosomal membranes, although much less potently than alpha-dendrotoxin. Based on the determined N-terminal amino acid sequence, the nucleotide sequence of the full-length cDNA (609bp) encoding AETX K was elucidated by a combination of degenerate RT-PCR, 3'RACE and 5'RACE. The precursor protein of AETX K is composed of a signal peptide (22 residues), a propart (27 residues) ended with a pair of basic residues (Lys-Arg) and a mature peptide (34 residues). AETX K is the sixth member of the type 1 potassium channel toxins from sea anemones, showing especially high sequence identities with HmK from Heteractis magnifica and ShK from Stichodactyla helianthus. It has six Cys residues at the same position as the known type 1 toxins. In addition, the dyad comprising Lys and Tyr, which is considered to be essential for the binding of the known type 1 toxins to potassium channels, is also conserved in AETX K.
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Affiliation(s)
- Yuichi Hasegawa
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Minato-ku, Tokyo 108-8477, Japan
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32
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Gutiérrez-Aguirre I, Trontelj P, Maček P, Lakey J, Anderluh G. Membrane binding of zebrafish actinoporin-like protein: AF domains, a novel superfamily of cell membrane binding domains. Biochem J 2006; 398:381-92. [PMID: 16737440 PMCID: PMC1559445 DOI: 10.1042/bj20060206] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Actinoporins are potent eukaryotic pore-forming toxins specific for sphingomyelin-containing membranes. They are structurally similar to members of the fungal fruit-body lectin family that bind cell-surface exposed Thomsen-Friedenreich antigen. In the present study we found a number of sequences in public databases with similarity to actinoporins. They originate from three animal and two plant phyla and can be classified in three families according to phylogenetic analysis. The sequence similarity is confined to a region from the C-terminal half of the actinoporin molecule and comprises the membrane binding site with a highly conserved P-[WYF]-D pattern. A member of this novel actinoporin-like protein family from zebrafish was cloned and expressed in Escherichia coli. It displays membrane-binding behaviour but does not have permeabilizing activity or sphingomyelin specificity, two properties typical of actinoporins. We propose that the three families of actinoporin-like proteins and the fungal fruit-body lectin family comprise a novel superfamily of membrane binding proteins, tentatively called AF domains (abbreviated from actinoporin-like proteins and fungal fruit-body lectins).
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Affiliation(s)
- Ion Gutiérrez-Aguirre
- *Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Peter Trontelj
- *Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Peter Maček
- *Department of Biology, Biotechnical Faculty, University of Ljubljana, Večna pot 111, 1000 Ljubljana, Slovenia
| | - Jeremy H. Lakey
- †Institute for Cell and Molecular Biosciences, University of Newcastle upon Tyne, Framlington Place, Newcastle upon Tyne NE2 4HH, U.K
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Ovchinnikova TV, Balandin SV, Aleshina GM, Tagaev AA, Leonova YF, Krasnodembsky ED, Men'shenin AV, Kokryakov VN. Aurelin, a novel antimicrobial peptide from jellyfish Aurelia aurita with structural features of defensins and channel-blocking toxins. Biochem Biophys Res Commun 2006; 348:514-23. [PMID: 16890198 DOI: 10.1016/j.bbrc.2006.07.078] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2006] [Accepted: 07/15/2006] [Indexed: 10/24/2022]
Abstract
A novel 40-residue antimicrobial peptide, aurelin, exhibiting activity against Gram-positive and Gram-negative bacteria, was purified from the mesoglea of a scyphoid jellyfish Aurelia aurita by preparative gel electrophoresis and RP-HPLC. Molecular mass (4296.95 Da) and complete amino acid sequence of aurelin (AACSDRAHGHICESFKSFCKDSGRNGVKLRANCKKTCGLC) were determined. Aurelin has six cysteines forming three disulfide bonds. The total RNA was isolated from the jellyfish mesoglea, RT-PCR and cloning were performed, and cDNA was sequenced. A 84-residue preproaurelin contains a putative signal peptide (22 amino acids) and a propiece of the same size (22 amino acids). Aurelin has no structural homology with any previously identified antimicrobial peptides but reveals partial similarity both with defensins and K+ channel-blocking toxins of sea anemones and belongs to ShKT domain family.
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Affiliation(s)
- Tatiana V Ovchinnikova
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya str. 16/10, 117997 Moscow, Russia.
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Honma T, Minagawa S, Nagai H, Ishida M, Nagashima Y, Shiomi K. Novel peptide toxins from acrorhagi, aggressive organs of the sea anemone Actinia equina. Toxicon 2005; 46:768-74. [PMID: 16183092 DOI: 10.1016/j.toxicon.2005.08.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2005] [Accepted: 08/02/2005] [Indexed: 11/25/2022]
Abstract
Two peptide toxins, acrorhagin I (50 residues) and II (44 residues), were isolated from special aggressive organs (acrorhagi) of the sea anemone Actinia equina by gel filtration on Sephadex G-50 and reverse-phase HPLC on TSKgel ODS-120T. The LD50 against crabs of acrorhagin I and II were estimated to be 520 and 80 microg/kg, respectively. 3'- and 5'-RACE established the amino acid sequences of the acrorhagin precursors. The precursor of acrorhagin I is composed of both signal and mature peptides and that of acrorhagin II has an additional sequence (propart) between signal and mature peptides. Acrorhagin I has no sequence homologies with any toxins, while acrorhagin II is somewhat similar to spider neurotoxins (hainantoxin-I from Selenocosmia hainana and Tx 3-2 from Phoneutria nigriventer) and cone snail neurotoxin (omega-conotoxin MVIIB from Conus magus). In addition, analogous peptides (acrorhagin Ia and IIa) were also cloned during RT-PCR experiments performed to confirm the nucleotide sequences of acrorhagins. This is the first to demonstrate the existence of novel peptide toxins in the sea anemone acrorhagi.
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Affiliation(s)
- Tomohiro Honma
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Minato-ku, Tokyo 108-8477, Japan
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35
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Honma T, Hasegawa Y, Ishida M, Nagai H, Nagashima Y, Shiomi K. Isolation and molecular cloning of novel peptide toxins from the sea anemone Antheopsis maculata. Toxicon 2005; 45:33-41. [PMID: 15581681 DOI: 10.1016/j.toxicon.2004.09.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2004] [Accepted: 09/16/2004] [Indexed: 10/26/2022]
Abstract
Three peptide toxins (Am I-III) with crab toxicity were isolated from the sea anemone Anthopleura maculata by gel filtration and reverse-phase HPLC. Am I was weakly lethal to crabs (LD50 830 microg/kg) and Am III was potently lethal (LD50 70 microg/kg), while Am II was only paralytic (ED50 420 microg/kg). The complete amino acid sequences of the three toxins were determined by cDNA cloning based on 3'-Race and 5'-Race. Although Am III (47 residues) is an analogue of the well-known type 1 sea anemone sodium channel toxins, both Am I (27 residues) and II (46 residues) are structurally novel peptide toxins. Am I is a new toxin having no sequence homologies with any toxins. Am II shares 28-39% identity with the recently characterized sea anemone toxins inhibiting specialized ion channels, BDS-I and II from Anemonia sulcata and APETx1 and 2 from Anthopleura elegantissima. The precursor proteins of the three toxins are commonly composed of a signal peptide, a propart with a pair of basic residues (Lys-Arg) at the end and the remaining portion. Very interestingly, the Am I precursor protein contains as many as six copies of Am I.
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Affiliation(s)
- Tomohiro Honma
- Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Konan-4, Minato-ku, Tokyo 108-8477, Japan
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36
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Abstract
Arthropods are the most diverse animal group on the planet. Their ability to inhabit a vast array of ecological niches has inevitably brought them into conflict with humans. Although only a small minority are classified as pest species, they nevertheless destroy about a quarter of the world's annual crop production and transmit an impressive array of pathogens of human and veterinary public health importance. Arthropod pests have been controlled almost exclusively with chemical insecticides since the introduction of DDT in the 1940s. However, the evolution of resistance to many insecticides, coupled with increased awareness of the potential environmental and human and animal health impacts of these chemicals, has stimulated the search for new insecticidal compounds, novel molecular targets, and alternative control methods. Spider venoms are complex chemical cocktails that have evolved to kill or paralyze arthropod prey, and they represent a largely untapped reservoir of insecticidal compounds. This review focuses on several families of invertebrate-specific peptide neurotoxins that were isolated from the venom of Australian funnel-web spiders. These peptides are promising insecticide leads because of their selectivity for invertebrates and activity on previously unvalidated targets. These toxins should facilitate the development of novel target-based screens for new insecticide leads, while their mapped pharmacophores will provide templates for rational design of mimetics that act at these target sites. Furthermore, genes encoding these toxins can be used to improve the efficacy of insect-specific viruses.
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Affiliation(s)
- Hugo W Tedford
- Department of Molecular, Microbial, and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06032-3305, USA
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37
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Honma T, Nagai H, Nagashima Y, Shiomi K. Molecular cloning of an epidermal growth factor-like toxin and two sodium channel toxins from the sea anemone Stichodactyla gigantea. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1652:103-6. [PMID: 14644045 DOI: 10.1016/j.bbapap.2003.08.007] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An epidermal growth factor (EGF)-like toxin (gigantoxin I) and two sodium channel toxins (gigantoxins II and III), previously isolated from the sea anemone Stichodactyla gigantea, were cloned for their cDNAs. The precursor protein of gigantoxin I is composed of a signal peptide, propart and mature peptide, similar to those of gigantoxins II and III, and is much simpler in structure than those of mammalian EGFs. In addition, gigantoxin I as well as gigantoxins II and III was demonstrated to be contained in nematocysts, suggesting that gigantoxin I functions as a toxin in S. gigantea.
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Affiliation(s)
- Tomohiro Honma
- Department of Food Science and Technology, Tokyo University of Fisheries, Konan-4, Minato, Tokyo 108-8477, Japan
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38
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Zhang M, Fishman Y, Sher D, Zlotkin E. Hydralysin, a novel animal group-selective paralytic and cytolytic protein from a noncnidocystic origin in hydra. Biochemistry 2003; 42:8939-44. [PMID: 12885226 DOI: 10.1021/bi0343929] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In Cnidaria, the production of neurotoxic polypeptides is attributed to the ectodermal stinging cells (cnidocytes), which are discharged for offensive (prey capture) and/or defensive purposes. In this study, a new paralysis-inducing (neurotoxic) protein from the green hydra Chlorohydra viridissima was purified, cloned, and expressed. This paralytic protein is unique in that it (1) is derived from a noncnidocystic origin, (2) reveals a clear animal group-selective toxicity, (3) possesses an uncommon primary structure, remindful of pore-forming toxins, and (4) has a fast cytotoxic effect on insect cells but not on the tested mammalian cells. The possible biological role of such a noncnidocystic toxin is discussed.
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Affiliation(s)
- Mingliang Zhang
- Department of Cell and Animal Biology, Silberman Institute of Life Sciences, Hebrew University, Jerusalem 91904, Israel
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39
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Liu WH, Wang L, Wang YL, Peng LS, Wu WY, Peng WL, Jiang XY, Tu HB, Chen HP, Ou-Yang P, Xu AL. Cloning and characterization of a novel neurotoxin from the sea anemone Anthopleura sp. Toxicon 2003; 41:793-801. [PMID: 12782079 DOI: 10.1016/s0041-0101(03)00033-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A full-length cDNA of neurotoxin (Hk2a) was isolated by RT-PCR of total RNA isolated from tentacles of Anthopleura sp. using degenerate oligonucleotide primers and 3',5'-RACE. The cDNA sequence of Hk2a encoded a polypeptide of 47 amino acids, which lacks a typical N-terminal signal sequences commonly found in proteins that are secreted via endoplasmic reticulum-Golgi pathway, indicating the possibility of secretion via a non-classical pathway. The neurotoxin has a predicted molecular mass of 4.8 kDa and a pI value of 7.62. The amino acid sequence of Hk2a is very similar to Anthopleurin C (Ap-C) and Neurotoxin I (Af I), and shares 95% amino acid sequence similarity to Ap-C. The coding region for the matured Hk2a toxin was cloned into the thioredoxin (TRX) fusion expression vector (pTRX) for the fusion expression in Escherichia coli. The recombinant polypeptide of Hk2a (rHk2a) was purified by the affinity chromatography, 15 mg/l of rHk2a was obtained after the digestion with protease 3C and further purification. The molecular weight of rHk2a (5.078 kDa) obtained by MALDI-TOF was very close to that (5Da) calculated from the sequence. The results of the UV-circular dichroism spectra of rHk2a indicates that its secondary structure is similar to that of Ap-B (), having 61.7% beta-sheet and no alpha-helix. Investigation on pharmacological effects of rHk2a in vitro was undertaken, and it was found that LD(50) of rHk2a was 1.4 mg/kg on NIH mice (i.p.). The rHk2a was demonstrated to increase contracting activity on isolated SD rat atria with the enhancing degree reaching 343.5+/-160.5%. The increase in contractile amplitude reached a plateau value within 3-5 min after addition of this toxin.
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Affiliation(s)
- Wen-Hua Liu
- The Open Laboratory for Marine Functional Genomics of State High-Tech Development, Department of Biochemistry, College of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China
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Ozbek S, Pertz O, Schwager M, Lustig A, Holstein T, Engel J. Structure/function relationships in the minicollagen of Hydra nematocysts. J Biol Chem 2002; 277:49200-4. [PMID: 12368276 DOI: 10.1074/jbc.m209401200] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The minicollagens found in the inner layer of the Hydra nematocyst walls are the smallest collagens known with 12-16 Gly-X-Y repeats. Minicollagen-1, the best characterized member of this protein family so far, consists of a central collagen triple helix of 12 nm in length flanked at both ends by a polyproline stretch and a conserved cysteine-rich domain. The cysteine-rich tails are proposed to function in the assembly of soluble minicollagen trimers to high molecular structures by a switch of the disulfide linkage from intramolecular to intermolecular bonds. In this study, we investigate the trimeric nature of minicollagen-1 and its capacity to form disulfide-linked polymers in vitro. A fusion protein of minicollagen-1 with maltose-binding protein is secreted as a soluble trimer with only intrachain and no interchain disulfide bridges as confirmed by melting the collagen triple helix under reducing and non-reducing conditions. The conversion of minicollagen-1 trimers to monomers takes place between 40 and 55 degrees C with the melting point being approximately 45 degrees C. Oxidative reshuffling of the minicollagen-1 trimers leads to the formation of high molecular aggregates, which upon reduction show distinct polytrimeric states. Minicollagen trimers in isolated nematocyst capsules proved to be sensitive to SDS and were engaged in polymeric structures with additional cross-links that were resistant to reducing agent.
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Affiliation(s)
- Suat Ozbek
- Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
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Jiang XY, Yang WL, Chen HP, Tu HB, Wu WY, Wei JW, Wang J, Liu WH, Xu AL. Cloning and characterization of an acidic cytolysin cDNA from sea anemone Sagartia rosea. Toxicon 2002; 40:1563-9. [PMID: 12419507 DOI: 10.1016/s0041-0101(02)00173-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A full-length cDNA of cytolysin (Src I) was isolated from the tentacle of Sagartia rosea (a representative species in China) by reverse transcription polymerase chain reaction. The cDNA with an open reading frame of 648 bp encodes a precursor protein of 216 amino acids, which contains a prepropeptide of 38 amino acids including a signal peptide of 19 amino acids and a propart of 19 amino acids. Lys-Pro at C-terminus of propart is a cleavage site for proline-endopeptidase-like protease. The mature cytolysin has a molecular mass of 19.6 kDa and a pI value of 4.8. Src I is an acidic cytolysin found in sea anemone and shares 75% amino acid sequence similarity to equinatoxin II (Eqt II). The predicted secondary structure of the mature cytolysin comprises 15% alpha-helix, 45% beta-sheet, and 40% random coil. The characteristic amphiphilic alpha-helix of cytolysin is located at the N-terminus of the processed Src I.
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Affiliation(s)
- Xiao-Yu Jiang
- The Open Laboratory for Marine Functional Genomics of National High-Tech Development, Department of Biochemistry, College of Life Sciences, Zhongshan (Sun Yat-Sen) University, Guangzhou 510275, People's Republic of China
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42
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Engel U, Ozbek S, Streitwolf-Engel R, Petri B, Lottspeich F, Holstein TW, Oezbek S, Engel R. Nowa, a novel protein with minicollagen Cys-rich domains, is involved in nematocyst formation in Hydra. J Cell Sci 2002; 115:3923-34. [PMID: 12244130 DOI: 10.1242/jcs.00084] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The novel protein Nowa was identified in nematocysts, explosive organelles of Hydra, jellyfish, corals and other Cnidaria. Biogenesis of these organelles is complex and involves assembly of proteins inside a post-Golgi vesicle to form a double-layered capsule with a long tubule. Nowa is the major component of the outer wall, which is formed very early in morphogenesis. The high molecular weight glycoprotein has a modular structure with an N-terminal sperm coating glycoprotein domain, a central C-type lectin-like domain, and an eightfold repeated cysteine-rich domain at the C-terminus. Interestingly, the cysteine-rich domains are homologous to the cysteine-rich domains of minicollagens. We have previously shown that the cysteines of these minicollagen cysteine-rich domains undergo an isomerization process from intra- to intermolecular disulfide bonds, which mediates the crosslinking of minicollagens to networks in the inner wall of the capsule. The minicollagen cysteine-rich domains present in both proteins provide a potential link between Nowa in the outer wall and minicollagens in the inner wall. We propose a model for nematocyst formation that integrates cytoskeleton rearrangements around the post-Golgi vesicle and protein assembly inside the vesicle to generate a complex structure that is stabilized by intermolecular disulfide bonds.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/metabolism
- Antigens, Surface/chemistry
- Antigens, Surface/metabolism
- Collagen/chemistry
- Collagen/metabolism
- Cysteine/chemistry
- Disulfides/chemistry
- Electrophoresis, Gel, Two-Dimensional
- Escherichia coli/genetics
- Glycoproteins/chemistry
- Glycoproteins/metabolism
- Glycosylation
- Hydra/cytology
- Hydra/metabolism
- Hydra/ultrastructure
- Microtubules/metabolism
- Microtubules/ultrastructure
- Models, Biological
- Molecular Sequence Data
- Molecular Weight
- Protein Conformation
- Protein Folding
- Protein Structure, Tertiary
- Protein Transport
- RNA, Messenger/metabolism
- Recombinant Proteins/metabolism
- Repetitive Sequences, Amino Acid
- Sequence Homology, Amino Acid
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Affiliation(s)
- Ulrike Engel
- Institute of Zoology, Darmstadt University of Technology, 64287 Darmstadt, Germany
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43
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Abstract
More than 32 species of sea anemones have been reported to produce lethal cytolytic peptides and proteins. Based on their primary structure and functional properties, cytolysins have been classified into four polypeptide groups. Group I consists of 5-8 kDa peptides, represented by those from the sea anemones Tealia felina and Radianthus macrodactylus. These peptides form pores in phosphatidylcholine containing membranes. The most numerous is group II comprising 20 kDa basic proteins, actinoporins, isolated from several genera of the fam. Actiniidae and Stichodactylidae. Equinatoxins, sticholysins, and magnificalysins from Actinia equina, Stichodactyla helianthus, and Heteractis magnifica, respectively, have been studied mostly. They associate typically with sphingomyelin containing membranes and create cation-selective pores. The crystal structure of equinatoxin II has been determined at 1.9A resolution. Lethal 30-40 kDa cytolytic phospholipases A(2) from Aiptasia pallida (fam. Aiptasiidae) and a similar cytolysin, which is devoid of enzymatic activity, from Urticina piscivora, form group III. A thiol-activated cytolysin, metridiolysin, with a mass of 80 kDa from Metridium senile (fam. Metridiidae) is a single representative of the fourth family. Its activity is inhibited by cholesterol or phosphatides. Biological, structure-function, and pharmacological characteristics of these cytolysins are reviewed.
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Affiliation(s)
- Gregor Anderluh
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Vecna pot 111,1000 Ljubljana, Slovenia
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Engel U, Pertz O, Fauser C, Engel J, David CN, Holstein TW. A switch in disulfide linkage during minicollagen assembly in Hydra nematocysts. EMBO J 2001; 20:3063-73. [PMID: 11406583 PMCID: PMC150192 DOI: 10.1093/emboj/20.12.3063] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The smallest known collagens with only 14 Gly-X-Y repeats referred to as minicollagens are the main constituents of the capsule wall of nematocysts. These are explosive organelles found in Hydra, jellyfish, corals and other Cnidaria. Minicollagen-1 of Hydra recombinantly expressed in mammalian 293 cells contains disulfide bonds within its N- and C-terminal Cys-rich domains but no interchain cross-links. It is soluble and self-associates through non-covalent interactions to form 25-nm-long trimeric helical rod-like molecules. We have used a polyclonal antibody prepared against the recombinant protein to follow the maturation of minicollagens from soluble precursors present in the endoplasmic reticulum and post-Golgi vacuoles to the disulfide-linked insoluble assembly form of the wall. The switch from intra- to intermolecular disulfide bonds is associated with 'hardening' of the capsule wall and provides an explanation for its high tensile strength and elasticity. The process is comparable to disulfide reshuffling between the NC1 domains of collagen IV in mammalian basement membranes.
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Affiliation(s)
| | - Olivier Pertz
- Institute of Zoology, Technical University of Darmstadt, Schnittspahnstrasse 10, D-64287 Darmstadt,
Institute of Zoology, University of Munich, Luisenstrasse 14, D-80333 Munich, Germany and Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland Present address: Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA Corresponding author e-mail:
U.Engel and O.Pertz contributed equally to this work
| | - Charlotte Fauser
- Institute of Zoology, Technical University of Darmstadt, Schnittspahnstrasse 10, D-64287 Darmstadt,
Institute of Zoology, University of Munich, Luisenstrasse 14, D-80333 Munich, Germany and Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland Present address: Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA Corresponding author e-mail:
U.Engel and O.Pertz contributed equally to this work
| | - Jürgen Engel
- Institute of Zoology, Technical University of Darmstadt, Schnittspahnstrasse 10, D-64287 Darmstadt,
Institute of Zoology, University of Munich, Luisenstrasse 14, D-80333 Munich, Germany and Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland Present address: Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA Corresponding author e-mail:
U.Engel and O.Pertz contributed equally to this work
| | - Charles N. David
- Institute of Zoology, Technical University of Darmstadt, Schnittspahnstrasse 10, D-64287 Darmstadt,
Institute of Zoology, University of Munich, Luisenstrasse 14, D-80333 Munich, Germany and Department of Biophysical Chemistry, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland Present address: Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA Corresponding author e-mail:
U.Engel and O.Pertz contributed equally to this work
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