Metabolismo do propionato em Paracoccidioides lutzii
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2015-01-30
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Universidade Federal de Goiás
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Pathogens can find different carbon sources in host niches generating propionyl-CoA, among them propionate. This compound is toxic to the organism if accumulated within the cell, and can be generated in the host tissue by the metabolism of amino acids isoleucine, valine and methionine, or by the metabolism of odd-chain fatty acids. Therefore, during infection, the propionyl-CoA metabolism to nontoxic nutrient and usable energetically is of great relevance. Nonetheless, there are no studies about the propionyl-CoA metabolization pathway in fungi of the genus Paracoccidioides, causer of paracoccidioidomycosis, a systemic mycosis of high incidence in Latin America. Thus, to characterize of which metabolic pathway this fungus utilizes to propionyl-CoA metabolization, it was made a search the genes coding to enzymes of methylcitrate cycle in genome of Paracoccidioides spp. and were identified genes coding to the three exclusive enzymes of this cycle, which are methylcitrate synthase, methylcitrate dehydrogenase and methylcitrate lyase. After analysis of growth and viability, which demonstrated that Paracoccidioides lutzii utilizes propionate as carbon source, it was made gene expression analysis of enzymes of methylcitrate cycle and was observed that are regulated in response to propionate. Additionally, the enzymatic activity of the MCS showed that this enzyme is active inside of fungal cells and also when is secreted, as well as its dual capacity of to act with a citrate synthase and metylcitrate synthase. Finally, the proteomic profile of P. lutzii in propionate showed enzymes induction of methylcitrate cycle, glyoxylate cycle, amino acid metabolism and gluconeogenesis, and the repression of glycolytic pathway, fermentation and fatty acid synthesis, which demonstrated of metabolic rearrangement to supply the cellular energetic demand, metabolizing propionate. In this sense, to understand the mechanism of propionyl-CoA metabolism in P. lutzii provides data for visualization of metabolic adaptation that this fungus makes use in different colonization of niches.
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SANTOS, L. P. A. Metabolismo do propionato em Paracoccidioides lutzii. 2015. 88 f. Dissertação (Mestrado em Medicina Tropical e Saúde Pública) - Universidade Federal de Goiás, Goiânia, 2015.