title: Proteomic and Real-Time PCR analyses of Saccharomyces cerevisiae VL3 exposed to microcystin-LR reveals a set of protein alterations transversal to several eukaryotic models.
abstract: Some of the most common toxins present in freshwater, in particular microcystins (MCs), are produced by cyanobacteria. These toxins have a negative impact on human health, being associated with episodes of acute hepatotoxicity and being considered potentially carcinogenic to humans. To date the exact mechanisms of MC-induced toxicity and tumor promotion were not completely elucidated. To get new insights underlying microcystin-LR (MCLR) molecular mechanisms of toxicity we have performed the proteomic profiling using two-dimensional electrophoresis and MALDI-TOF/TOF of Saccharomyces cerevisiae cells exposed for 4 h-1 nM and 1 μM of MCLR, and compared them to the control (cells not exposed to MCLR). We identified 14 differentially expressed proteins. The identified proteins are involved in metabolism, genotoxicity, cytotoxicity and stress response. Furthermore, we evaluated the relative expression of yeast's PP1 and PP2A genes and also of genes from the Base Excision Repair (BER) DNA-repair system, and observed that three out of the five genes analyzed displayed dose-dependent responses. Overall, the different proteins and genes affected are related to oxidative stress and apoptosis, thus reinforcing that it is probably the main mechanism of MCLR toxicity transversal to several organisms, especially at lower doses. Notwithstanding these MCLR responsive proteins could be object of further studies to evaluate their suitability as biomarkers of exposure to the toxin.
authors.affiliation: Unidade de Água e Solo, Departamento de Saúde Ambiental, Instituto Nacional de Saúde Doutor Ricardo Jorge, Avenida Padre Cruz, 1649-016, Lisboa, Portugal; Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal. Electronic address: elisabete.valerio@insa.min-saude.pt.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Valério
authors.affiliation: Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Campos
authors.affiliation: IPATIMUP - Institute of Molecular Pathology and Immunology of the University of Porto, 4200-465, Porto, Portugal; Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal.
authors.forename: Hugo
authors.initials: H
authors.lastname: Osório
authors.affiliation: Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Universidade do Porto, Rua dos Bragas 289, 4050-123, Porto, Portugal; Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4069-007, Porto, Portugal.
authors.forename: Vitor
authors.initials: V
authors.lastname: Vasconcelos
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001427:Bacterial Toxins / Q000633:toxicity*; D004260:DNA Repair / Q000187:drug effects; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects*; D008387:Marine Toxins / Q000633:toxicity*; D052998:Microcystins / Q000633:toxicity*; D009994:Osmolar Concentration; D018384:Oxidative Stress / Q000187:drug effects; D040901:Proteomics / Q000379:methods; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D057825:Two-Dimensional Difference Gel Electrophoresis
chemical_list: D001427:Bacterial Toxins; D008387:Marine Toxins; D052998:Microcystins; D029701:Saccharomyces cerevisiae Proteins; C057862:cyanoginosin LR
keywords: 2-DE proteomics; Gene expression; Microcystin-LR; Protein expression; RT-qPCR; Saccharomyces cerevisiae