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...

Full description

Bibliographic Details
Main Authors: Aldo Nicosia, Teresa Maggio, Salvatore Mazzola, Angela Cuttitta
Format: Article
Language:English
Published: MDPI AG 2013-10-01
Series:Marine Drugs
Subjects:
Online Access:http://www.mdpi.com/1660-3397/11/11/4213
_version_ 1811262794535796736
author Aldo Nicosia
Teresa Maggio
Salvatore Mazzola
Angela Cuttitta
author_facet Aldo Nicosia
Teresa Maggio
Salvatore Mazzola
Angela Cuttitta
author_sort Aldo Nicosia
collection DOAJ
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 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.
first_indexed 2024-04-12T19:32:01Z
format Article
id doaj.art-5d9fb224cedd4734ab4dbfd953810420
institution Directory Open Access Journal
issn 1660-3397
language English
last_indexed 2024-04-12T19:32:01Z
publishDate 2013-10-01
publisher MDPI AG
record_format Article
series Marine Drugs
spelling doaj.art-5d9fb224cedd4734ab4dbfd9538104202022-12-22T03:19:18ZengMDPI AGMarine Drugs1660-33972013-10-0111114213423110.3390/md11114213Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridisAldo NicosiaTeresa MaggioSalvatore MazzolaAngela CuttittaAnemonia 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.http://www.mdpi.com/1660-3397/11/11/4213Anemonia viridisBDS peptidesaccelerated evolutionmolecular modellingtissue-specific librariesgene expression pattern
spellingShingle Aldo Nicosia
Teresa Maggio
Salvatore Mazzola
Angela Cuttitta
Evidence of Accelerated Evolution and Ectodermal-Specific Expression of Presumptive BDS Toxin cDNAs from Anemonia viridis
Marine Drugs
Anemonia viridis
BDS peptides
accelerated evolution
molecular modelling
tissue-specific libraries
gene expression pattern
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 Anemonia viridis
BDS peptides
accelerated evolution
molecular modelling
tissue-specific libraries
gene expression pattern
url http://www.mdpi.com/1660-3397/11/11/4213
work_keys_str_mv AT aldonicosia evidenceofacceleratedevolutionandectodermalspecificexpressionofpresumptivebdstoxincdnasfromanemoniaviridis
AT teresamaggio evidenceofacceleratedevolutionandectodermalspecificexpressionofpresumptivebdstoxincdnasfromanemoniaviridis
AT salvatoremazzola evidenceofacceleratedevolutionandectodermalspecificexpressionofpresumptivebdstoxincdnasfromanemoniaviridis
AT angelacuttitta evidenceofacceleratedevolutionandectodermalspecificexpressionofpresumptivebdstoxincdnasfromanemoniaviridis