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Special Issue "Genomics and Proteomics of Cyanotoxins"

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A special issue of Toxins (ISSN 2072-6651).

Deadline for manuscript submissions: closed (30 April 2014)

Special Issue Editors

Guest Editor
Prof. Dr. Vítor Vasconcelos

Faculty of Sciences, University of Porto, Rua do Campo Alegre, 4069-007 Porto, Portugal
Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Terminal de Cruzeiros do Porto de Leixões, Av. General Norton de Matos, s/n, 4450-208 Matosinhos, Portugal
Website | E-Mail
Phone: +351 223401814
Fax: +351 223380609
Interests: blue-biotechnology; emerging marine toxins; bioassay-guided approach; cyanobacteria bioactive compounds
Guest Editor
Dr. Agostinho Antunes

Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Rua dos Bragas, 289, 4050-123 Porto, Portugal and Department of Biology, Faculty of Sciences, Porto University, Rua do Campo Alegre 4069-007 Porto
E-Mail
Fax: +351 22 3390 608
Interests: genomics, evolution and bioinformatics; ecotoxicogenomics; diversity of toxin and venom compounds; blue-biotechnology
Guest Editor
Dr. Alexandre Campos

Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), Rua dos Bragas, 289, 4050-123 Porto, Portugal
Website | E-Mail
Fax: +351 223390608
Interests: proteomics; toxicology; emerging water pollutants; cyanobacteria bioactive metabolites and enzymes

Special Issue Information

Dear Colleagues,

Cyanobacteria toxins have a diversity of modes of action that are only partially known. Studies on protein differential expression may help us to map new targets for some of these toxins and the pathways of their detoxication metabolism. Advances in genomic approaches have also enhanced the way we understand toxin production and regulation, including the phylogeny of cyanotoxins.

This Special Issue will cover all aspects related to genomics and proteomics approaches on the study of cyanotoxins.

Prof. Dr. Vítor Vasconcelos
Dr. Agostinho Antunes
Dr. Alexandre Campos
Guest Editors

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxins is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1400 CHF (Swiss Francs).


Keywords

  • comparative proteomics and genomics
  • mechanisms of action of cyanotoxins and toxin–protein interactions
  • method development and identification of novel cyanotoxins
  • molecular evolution of cyanotoxins
  • de novo sequencing and posttranslational modifications of cyanotoxins
  • Cyanotoxins biosynthetic pathways
  • metagenomics of cyanotoxins
  • phylogenetics of cyanotoxins
  • molecular evolution of polyketide synthase [PKS] and nonribosomal peptide synthase [NRPS]
  • molecular diversity of cyanotoxins

Published Papers (4 papers)

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Research

Jump to: Review

Open AccessArticle Impact of Nitrogen Sources on Gene Expression and Toxin Production in the Diazotroph Cylindrospermopsis raciborskii CS-505 and Non-Diazotroph Raphidiopsis brookii D9
Toxins 2014, 6(6), 1896-1915; doi:10.3390/toxins6061896
Received: 1 May 2014 / Revised: 31 May 2014 / Accepted: 9 June 2014 / Published: 20 June 2014
Cited by 12 | PDF Full-text (1136 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Different environmental nitrogen sources play selective roles in the development of cyanobacterial blooms and noxious effects are often exacerbated when toxic cyanobacteria are dominant. Cylindrospermopsis raciborskii CS-505 (heterocystous, nitrogen fixing) and Raphidiopsis brookii D9 (non-N2 fixing) produce the nitrogenous toxins cylindrospermopsin (CYN)
[...] Read more.
Different environmental nitrogen sources play selective roles in the development of cyanobacterial blooms and noxious effects are often exacerbated when toxic cyanobacteria are dominant. Cylindrospermopsis raciborskii CS-505 (heterocystous, nitrogen fixing) and Raphidiopsis brookii D9 (non-N2 fixing) produce the nitrogenous toxins cylindrospermopsin (CYN) and paralytic shellfish toxins (PSTs), respectively. These toxin groups are biosynthesized constitutively by two independent putative gene clusters, whose flanking genes are target for nitrogen (N) regulation. It is not yet known how or if toxin biosynthetic genes are regulated, particularly by N-source dependency. Here we show that binding boxes for NtcA, the master regulator of N metabolism, are located within both gene clusters as potential regulators of toxin biosynthesis. Quantification of intra- and extracellular toxin content in cultures at early stages of growth under nitrate, ammonium, urea and N-free media showed that N-sources influence neither CYN nor PST production. However, CYN and PST profiles were altered under N-free medium resulting in a decrease in the predicted precursor toxins (doCYN and STX, respectively). Reduced STX amounts were also observed under growth in ammonium. Quantification of toxin biosynthesis and transport gene transcripts revealed a constitutive transcription under all tested N-sources. Our data support the hypothesis that PSTs and CYN are constitutive metabolites whose biosynthesis is correlated to cyanobacterial growth rather than directly to specific environmental conditions. Overall, the constant biosynthesis of toxins and expression of the putative toxin-biosynthesis genes supports the usage of qPCR probes in water quality monitoring of toxic cyanobacteria. Full article
(This article belongs to the Special Issue Genomics and Proteomics of Cyanotoxins)
Open AccessArticle Exposure of Lycopersicon Esculentum to Microcystin-LR: Effects in the Leaf Proteome and Toxin Translocation from Water to Leaves and Fruits
Toxins 2014, 6(6), 1837-1854; doi:10.3390/toxins6061837
Received: 26 March 2014 / Revised: 30 May 2014 / Accepted: 3 June 2014 / Published: 11 June 2014
Cited by 7 | PDF Full-text (990 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Natural toxins such as those produced by freshwater cyanobacteria have been regarded as an emergent environmental threat. However, the impact of these water contaminants in agriculture is not yet fully understood. The aim of this work was to investigate microcystin-LR (MC-LR) toxicity in
[...] Read more.
Natural toxins such as those produced by freshwater cyanobacteria have been regarded as an emergent environmental threat. However, the impact of these water contaminants in agriculture is not yet fully understood. The aim of this work was to investigate microcystin-LR (MC-LR) toxicity in Lycopersicon esculentum and the toxin accumulation in this horticultural crop. Adult plants (2 month-old) grown in a greenhouse environment were exposed for 2 weeks to either pure MC-LR (100 μg/L) or Microcystis aeruginosa crude extracts containing 100 μg/L MC-LR. Chlorophyll fluorescence was measured, leaf proteome investigated with two-dimensional gel electrophoresis and Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF)/TOF, and toxin bioaccumulation assessed by liquid chromatography-mass spectrometry (LC-MS)/MS. Variations in several protein markers (ATP synthase subunits, Cytochrome b6-f complex iron-sulfur, oxygen-evolving enhancer proteins) highlight the decrease of the capacity of plants to synthesize ATP and to perform photosynthesis, whereas variations in other proteins (ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit and ribose-5-phosphate isomerase) suggest an increase of carbon fixation and decrease of carbohydrate metabolism reactions in plants exposed to pure MC-LR and cyanobacterial extracts, respectively. MC-LR was found in roots (1635.21 μg/kg fw), green tomatoes (5.15–5.41 μg/kg fw), mature tomatoes (10.52–10.83 μg/kg fw), and leaves (12,298.18 μg/kg fw). The results raise concerns relative to food safety and point to the necessity of monitoring the bioaccumulation of water toxins in agricultural systems affected by cyanotoxin contamination. Full article
(This article belongs to the Special Issue Genomics and Proteomics of Cyanotoxins)

Review

Jump to: Research

Open AccessReview Impact of Environmental Factors on the Regulation of Cyanotoxin Production
Toxins 2014, 6(7), 1951-1978; doi:10.3390/toxins6071951
Received: 30 April 2014 / Revised: 6 June 2014 / Accepted: 17 June 2014 / Published: 25 June 2014
Cited by 23 | PDF Full-text (1005 KB) | HTML Full-text | XML Full-text
Abstract
Cyanobacteria are capable of thriving in almost all environments. Recent changes in climatic conditions due to increased human activities favor the occurrence and severity of harmful cyanobacterial bloom all over the world. Knowledge of the regulation of cyanotoxins by the various environmental factors
[...] Read more.
Cyanobacteria are capable of thriving in almost all environments. Recent changes in climatic conditions due to increased human activities favor the occurrence and severity of harmful cyanobacterial bloom all over the world. Knowledge of the regulation of cyanotoxins by the various environmental factors is essential for effective management of toxic cyanobacterial bloom. In recent years, progress in the field of molecular mechanisms involved in cyanotoxin production has paved the way for assessing the role of various factors on the cyanotoxin production. In this review, we present an overview of the influence of various environmental factors on the production of major group of cyanotoxins, including microcystins, nodularin, cylindrospermopsin, anatoxins and saxitoxins. Full article
(This article belongs to the Special Issue Genomics and Proteomics of Cyanotoxins)
Open AccessReview Oligopeptides as Biomarkers of Cyanobacterial Subpopulations. Toward an Understanding of Their Biological Role
Toxins 2014, 6(6), 1929-1950; doi:10.3390/toxins6061929
Received: 23 April 2014 / Revised: 9 June 2014 / Accepted: 16 June 2014 / Published: 23 June 2014
Cited by 13 | PDF Full-text (552 KB) | HTML Full-text | XML Full-text
Abstract
Cyanobacterial oligopeptides comprise a wide range of bioactive and/or toxic compounds. While current research is strongly focused on exploring new oligopeptide variants and their bioactive properties, the biological role of these compounds remains elusive. Oligopeptides production abilities show a remarkably patchy distribution among
[...] Read more.
Cyanobacterial oligopeptides comprise a wide range of bioactive and/or toxic compounds. While current research is strongly focused on exploring new oligopeptide variants and their bioactive properties, the biological role of these compounds remains elusive. Oligopeptides production abilities show a remarkably patchy distribution among conspecific strains. This observation has prompted alternative approaches to unveil their adaptive value, based on the use of cellular oligopeptide compositions as biomarkers of intraspecific subpopulations or chemotypes in freshwater cyanobacteria. Studies addressing the diversity, distribution, and dynamics of chemotypes in natural systems have provided important insights into the structure and ecology of cyanobacterial populations and the adaptive value of oligopeptides. This review presents an overview of the fundamentals of this emerging approach and its most relevant findings, and discusses our current understanding of the role of oligopeptides in the ecology of cyanobacteria. Full article
(This article belongs to the Special Issue Genomics and Proteomics of Cyanotoxins)

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Type of Paper: Review
Title:
Oligopeptides as Biomarkers of Cyanobacterial Subpopulations. Unraveling Their Biological Role
Authors:
Ramsy Agha and Antonio Quesada
Affiliation:
Departamento de Biología, Universidad Autónoma de Madrid, 28049 Madrid, Spain; E-Mail: antonio.quesada@uam.es (A.Q.)
Abstract
: Cyanobacterial oligopeptides comprise a wide range of bioactive and/or toxic compounds. While current research is strongly focused on describing new oligopeptide variants and their bioactive properties, the biological role of these compounds remains elusive. The distribution of oligopeptides production abilities among conspecific strains is remarkably heterogeneous. This observation has prompted in the last years the use oligopeptide compositions as biomarkers of coexisting intraspecific subpopulations or chemotypes. Studies addressing the diversity, distribution and dynamics of chemotypes in natural systems have provided important insights into the structure and ecology of cyanobacterial populations and the adaptive value of oligopeptides. This review presents an overview of the main findings obtained from this emerging approach and critically discusses our current understanding on the role of oligopeptides in the ecology of cyanobacteria.

Type of Paper: Article
Title:
Impact of Nitrogen Sources on Gene Expression and Toxin Production in the Diazotroph Cylindrospermopsis raciborskii CS-505 and Non-diazotroph Raphidiopsis brookii D9
Authors:
Karina Stucken 1, Uwe John 1, Allan Cembella 1, Katia Soto-Liebe 2,3 and Mónica Vásquez 2,3,*
Affiliations:
1 Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany; E-Mails: kstucken@ifam.uni-kiel.de (K.S.); Uwe.John@awi.de (U.J.)
2 Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile
3 Millenium Nucleus EMBA, Alameda 340, Santiago, Chile
Abstract: Different environmental nitrogen sources play selective roles in the development of cyanobacterial blooms and noxious effects are often exacerbated when toxic cyanobacteria are dominant. Cylindrospermopsis raciborskii CS-505 (heterocystous, nitrogen fixing) and Raphidiopsis brookii D9 (non-N2 fixing) produce the nitrogenous toxins cylindrospermopsin (CYN) and paralytic shellfish toxins (PSTs), respectively. These toxin groups are biosynthesized constitutively by two independent putative gene clusters, whose flanking genes are target for nitrogen (N) regulation. So far it is not known how or if toxin biosynthetic genes are regulated, particularly by N-source dependency. Here we show that binding boxes for NtcA, the master regulator of N metabolism are located within both gene clusters, as potential regulator of toxin biosynthesis. Quantification of intra- and extracellular toxin content in cultures at early stages of growth under nitrate, ammonium, urea and N-deprivation free medium showed that N-sources influence neither CYN nor PSTs production. However, CYN and PSTs profiles were altered under N deprivation resulting in a decrease in the predicted precursor toxins (doCYN and STX, respectively). Reduced STX amounts were also observed under growth in ammonium. Quantification of toxin biosynthesis and transport gene transcripts revealed a constitutive transcription under all N-sources. Our data support the hypothesis that PSTs and CYN are constitutive metabolites whose biosynthesis is correlated to cyanobacterial growth rather than directly to specific environmental conditions. Overall, the constant toxin biosynthesis and gene expression supports the usage of qPCR probes in water quality monitoring of toxic cyanobacteria.

Title: Proteomic Analysis of Anatoxin-a Acute Toxicity in Zebrafish Reveals Major Gender Specific Responses and Additional Mechanisms of Cell Stress
Authors: Mariana Carneiro 1, Daniel Gutiérrez-Praena 2, Hugo Osório 3,4, Vitor Vasconcelos 1,5, António Paulo Carvalho 1,5,* and Alexandre Campos 1
Affiliations:
1 Interdisciplinary Centre of Marine and Environmental Research, CIIMAR/CIMAR, Porto, Portugal; E-Mail address: apcarval@fc.up.pt (A.P.C.)
2 Area of Toxicology, Faculty of Pharmacy, University of Seville, Seville, Spain
3 Institute of Molecular Pathology and Immunology of the University of Porto, IPATIMUP, Porto, Portugal
4 Faculty of Medicine, University of Porto, Porto, Portugal
5 Department of Biology, Faculty of Sciences of the University of Porto, Porto, Portugal
Abstract
: Anatoxin-a is a potent neurotoxin produced by several genus of cyanobacteria known to form blooms in fresh and brackish waters, with a widespread geographic distribution. A number of deaths of wild and domestic animals due to anatoxin-a exposure has been reported. However, information on the mechanisms of toxicity and effects of this neurotoxin, particularly on aquatic animals, is still scarce. The present work aimed at evaluating proteome changes in brain and muscle of zebrafish (Danio rerio), caused by exposure to anatoxin-a. In this regard a test group of male and female zebrafish received an intraperitoneal (i.p.) injection of an anatoxin-a dose of 0.8 µg g-1 of fish body weight (bw), in phosphate buffered saline solution (PBS), while the control group received an i.p. injection of PBS only. After 5 minutes, fish were sacrificed and brain and muscle tissues were collected and processed with two-dimensional gel electrophoresis (2DE). Qualitative and statistical analyses of protein expression, using gel image tools, allowed the detection of differences between the proteome of control and exposed fish groups, as well as differences between the proteome of male and female fish (gender specific responses). The posterior MALDI-TOF mass spectrometry analysis, allowed to identify the up- and down regulated proteins. Alterations in proteins involved in carbohydrate metabolism and energy production, ATP synthesis, cell structure maintenance, cellular transport, protein folding and stress response, detoxification and protease inhibition, were reported, providing novel mechanistic insights relative to the action of anatoxin-a in fish.

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