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Carbon sources and XlnR-dependent transcriptional landscape of CAZymes in the industrial fungus Talaromyces versatilis: when exception seems to be the rule.
Llanos, Agustina; Déjean, Sébastien; Neugnot-Roux, Virginie; François, Jean M; Parrou, Jean-Luc.
Afiliação
  • Llanos A; LISBP, Université de Toulouse, INSA, INRA, CNRS, Toulouse, France.
  • Déjean S; Adisseo France S.A.S, 135 Avenue de Rangueil, 31077, Toulouse, France.
  • Neugnot-Roux V; Institut de Mathématiques de Toulouse, UMR5219-Université de Toulouse; CNRS-UPS, 31062, Toulouse Cedex 9, France.
  • François JM; Adisseo France S.A.S, 135 Avenue de Rangueil, 31077, Toulouse, France.
  • Parrou JL; LISBP, Université de Toulouse, INSA, INRA, CNRS, Toulouse, France.
Microb Cell Fact ; 18(1): 14, 2019 Jan 28.
Article em En | MEDLINE | ID: mdl-30691469
BACKGROUND: Research on filamentous fungi emphasized the remarkable redundancy in genes encoding hydrolytic enzymes, the similarities but also the large differences in their expression, especially through the role of the XlnR/XYR1 transcriptional activator. The purpose of this study was to evaluate the specificities of the industrial fungus Talaromyces versatilis, getting clues into the role of XlnR and the importance of glucose repression at the transcriptional level, to provide further levers for cocktail production. RESULTS: By studying a set of 62 redundant genes representative of several categories of enzymes, our results underlined the huge plasticity of transcriptional responses when changing nutritional status. As a general trend, the more heterogeneous the substrate, the more efficient to trigger activation. Genetic modifications of xlnR led to significant reorganisation of transcriptional patterns. Just a minimal set of genes actually fitted in a simplistic model of regulation by a transcriptional activator, and this under specific substrates. On the contrary, the diversity of xlnR+ versus ΔxlnR responses illustrated the existence of complex and unpredicted patterns of co-regulated genes that were highly dependent on the culture condition, even between genes that encode members of a functional category of enzymes. They notably revealed a dual, substrate-dependant repressor-activator role of XlnR, with counter-intuitive transcripts regulations that targeted specific genes. About glucose, it appeared as a formal repressive sugar as we observed a massive repression of most genes upon glucose addition to the mycelium grown on wheat straw. However, we also noticed a positive role of this sugar on the basal expression of a few genes, (notably those encoding cellulases), showing again the strong dependence of these regulatory mechanisms upon promoter and nutritional contexts. CONCLUSIONS: The diversity of transcriptional patterns appeared to be the rule, while common and stable behaviour, both within gene families and with fungal literature, the exception. The setup of a new biotechnological process to reach optimized, if not customized expression patterns of enzymes, hence appeared tricky just relying on published data that can lead, in the best scenario, to approximate trends. We instead encourage preliminary experimental assays, carried out in the context of interest to reassess gene responses, as a mandatory step before thinking in (genetic) strategies for the improvement of enzyme production in fungi.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Transcrição Gênica / Proteínas Fúngicas / Carbono / Regulação Enzimológica da Expressão Gênica / Transativadores / Talaromyces Tipo de estudo: Prognostic_studies Idioma: En Revista: Microb Cell Fact Assunto da revista: BIOTECNOLOGIA / MICROBIOLOGIA Ano de publicação: 2019 Tipo de documento: Article País de afiliação: França

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Transcrição Gênica / Proteínas Fúngicas / Carbono / Regulação Enzimológica da Expressão Gênica / Transativadores / Talaromyces Tipo de estudo: Prognostic_studies Idioma: En Revista: Microb Cell Fact Assunto da revista: BIOTECNOLOGIA / MICROBIOLOGIA Ano de publicação: 2019 Tipo de documento: Article País de afiliação: França