Análise dos transportadores Mup1 e Mup3 em Cryptococcus neoformans e sua importância para os fatores de virulência e captação de aminoácidos

• Ano de defesa: 2016
• Autor(a) principal: Martho, Kevin Felipe Cruz [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo
• Palavras-chave em Português: Permease; Amino acid; Cryptococcus Neoformans; Virulence factors; Assimilation; Aminoácidos; Fatores de virulência; Assimilação
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=4100166; https://repositorio.unifesp.br/handle/11600/47545

The increase in immunocompromised population due to invasive medical procedures and AIDS correlates with high incidence of infections, among which stand out those caused by opportunistic fungi. Invasive Fungal Infections (IFIs), which are common in immunosuppressed patients, are difficult to treat due to small number of antifungal drugs, which reflects the reduced number of molecular targets, since the pathogen and the host are both eukaryotes. C. neoformans is opportunistic yeast that causes fungal meningitis, a disease with high mortality rate. Moreover, it is considered a model for virulence and pathogenesis studies, due to the biological features and technological advances. The uptake, biosynthesis and recycling of nutrients by the cell have been identified as useful antifungal drug targets, since these biological processes are divergent between the upper and lower eukaryotes. Cryptococcus group at Microbial Interactions Laboratory at UNIFESP uses C. neoformans and genetic engineering techniques to evaluate the potential of biosynthetic and amino acids uptake pathways as targets for antifungal development. The group demonstrated that methionine and tryptophan biosynthetic pathways are very important for the survival and virulence. In this work we studied two C. neoformans genes which encode proteins with sequence similarity to both high and low affinity methionine permeases in Saccharomyces cerevisiae (Mup1 and Mup3). Gene deletion, separately and in combination (single and double mutants), phenotypic analysis, virulence factors expression, in vitro and in vivo survival and synergism to antifungal agents were used to test if C. neoformans Mup1 and Mup3 would be good targets. The results indicate that the single and double mutations did not cause significant impact on virulence, but they do affect the assimilation of some amino acids as the sole nitrogen source, especially 37°C, suggesting these are not methionine specific, as in S. cerevisiae, but global permeases.