Antifungal drug resistance driven by mistranslation in yeast

• Autor(a) principal: Araújo, Ana Rita Dias
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/7942
• topic: Biotecnologia; Agentes antifúngicos; Leveduras; Tradução genética

Antifungal drug resistance has become a severe clinical problem and new targets for the development of new antifungal drugs need to be discovered. Ongoing work in our laboratory indicates that codon mistranslation due to codon ambiguity accelerates antifungal drug resistance in the human pathogen Candida albicans. The present work aimed to elucidate if non pathogenic yeasts behave similarly. Therefore, mistranslation was artificially induced in Saccharomyces cerevisiae strains by the expression of chimeric tRNAs. Each of the constructed strains carried a low-copy number plasmid, containing a C. albicans tRNAUGA Ser gene, whose anticodon was changed by site-directed mutagenesis, in order to replace it by several other anticodons. As the identity elements of the tRNA remained unchanged it was still acylated with serine. These mutant tRNAs are expected to compete with the native ones and have an impact on the proteome. To verify if mistranslation leads to an advantageous phenotype regarding antifungal drug resistance, cells were exposed to different antifungals. Additionally, microarray analyses were performed on non-exposed mutant strains in order to detect a possible predisposition to resist antifungal exposure.