Identificação proteômica, expressão heteróloga, citolocalização, estudos de regulação transcricional e traducional da Aconitase Mitocondrial de Paracoccidioides brasiliensis

• Ano de defesa: 2009
• Autor(a) principal: BRITO, Wesley de Almeida
• Orientador(a): SOARES, Célia Maria de Almeida
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Goiás
• Programa de Pós-Graduação: Doutorado em Biologia
• Departamento: Ciencias Biologicas
• País: BR
• Palavras-chave em Português: 1. Paracoccidioides brasiliensis; 2. Aconitase; 3. Proteômica; 1. Paracoccidioides brasiliensis; 2. Aconitase; 3.Proteômica
• Palavras-chave em Inglês: 1. Paracoccidioides brasiliensis; 2. Aconitase; 3. Mass spectrometry; 4. Cellular localization 5. Carbon sources
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BIOQUIMICA::BIOLOGIA MOLECULAR
• Link de acesso: http://repositorio.bc.ufg.br/tede/handle/tde/1018

Paracoccidioides brasiliensis is a thermal-dimorphic fungus, the causative agent of Paracoccidioidomycosis (PCM), an important endemic mycosis in Latin America. A protein species preferentially expressed in yeast cells with a molecular mass of 80kDa and isoeletric point (pI) of 7.79 was isolated from the proteome of P. brasiliensis and characterized as an aconitase (E.C. 4.2.1.3). Aconitase is an enzyme that catalyzes the isomerization of citrate to isocitrate in both the Krebs cycle (KC) and the glyoxylate cycle (GC). We report the cloning and characterization of the cDNA encoding the aconitase of P. brasiliensis (PbACO). The cDNA showed a 2337 bp open reading frame (ORF) and encoded a predicted protein with 779 amino acids. A polyclonal antibody against the purified recombinant PbACO was obtained in order to analyze the subcellular localization of the molecule in P. brasiliensis. The protein is present in the extracellular fluid, cell wall, mitochondria, cytosol and peroxisomes of yeast cells as demonstrated by western blot and immunocytochemistry analysis. The expression analysis of the Pbaco gene was performed through quantitative real time RT-PCR and results demonstrated increasing expression during differentiation from mycelium to yeast cells. Real time RT-PCR assays was also used to evaluate the Pbaco expression when the fungus grows on media with acetate and ethanol as sole carbon sources and in different iron levels. The results demonstrated that Pbaco transcript is over expressed in acetate and ethanol as sole carbon sources and in highiron conditions.