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Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis

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...

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Autores principales: Nicosia, Aldo, Maggio, Teresa, Mazzola, Salvatore, Cuttitta, Angela
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853724/
https://www.ncbi.nlm.nih.gov/pubmed/24177670
http://dx.doi.org/10.3390/md11114213
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author Nicosia, Aldo
Maggio, Teresa
Mazzola, Salvatore
Cuttitta, Angela
author_facet Nicosia, Aldo
Maggio, Teresa
Mazzola, Salvatore
Cuttitta, Angela
author_sort Nicosia, Aldo
collection PubMed
description 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 K(A)/K(S) 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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spelling pubmed-38537242013-12-06 Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis Nicosia, Aldo Maggio, Teresa Mazzola, Salvatore Cuttitta, Angela Mar Drugs Article 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 K(A)/K(S) 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. MDPI 2013-10-30 /pmc/articles/PMC3853724/ /pubmed/24177670 http://dx.doi.org/10.3390/md11114213 Text en © 2013 by the authors; licensee MDPI, Basel, Switzerland. http://creativecommons.org/licenses/by/3.0/ This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Article
Nicosia, Aldo
Maggio, Teresa
Mazzola, Salvatore
Cuttitta, Angela
Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
title Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
title_full Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
title_fullStr Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
title_full_unstemmed Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
title_short Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
title_sort evidence of accelerated evolution and ectodermal-specific expression of presumptive bds toxin cdnas from anemonia viridis
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3853724/
https://www.ncbi.nlm.nih.gov/pubmed/24177670
http://dx.doi.org/10.3390/md11114213
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