Caracterização de anidrases carbônicas do fungo Paracoccidioides brasiliensis

• Autor(a) principal: Tomazett, Mariana Vieira
• Data de Publicação: 2011
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/4533
• topic: Paracoccidioides brasiliensis; Anidrase carbônica; Hipóxia; Paracoccidioides brasiliensis; Carbonic anhydrases; Hypoxia; CIENCIAS BIOLOGICAS::BIOLOGIA GERAL

Paracoccidioidomycosis (PCM) is the most important endemic deep mycosis in Latin America. Understanding of the complex interactions between the fungus and host must include the identification of gene expression patterns during infection. Carbonic anhydrase (CA) belongs to the family of zinc metalloenzymes that catalyzes the reversible hydratation of carbon dioxide to bicarbonate. Transcriptional studies have shown that carbonic anhydrase of P. brasiliensis is expressed in yeast cells recovered from liver of infected mice. In the present work, we characterized the cDNAs encoding for four carbonic anhydrases of P.brasiliensis (PbCA1, PbCA2, PbCA3, PbCA4). Recombinant PbCA1, 3 and 4 were obtained in heterologous systems with 33 kDa, 28 kDa and 32 kDa respectively. Mass spectrometry analysis confirmed the sequences of the produced proteins. The expression of PbCAs transcripts was evaluated by using real-time RT-PCR in mycelium, yeast cells and mycelium to yeast transition, in yeast cells exposed to CO2 and yeast cells recovery directly from liver and spleen. In the presence of CO2, PbCA1, PbCA2 and PbCA4 gene expression was reduced in the course of time. PbCA1 transcript expression was induced during the mycelium to yeast transition. PbCA2 and PbCA4 gene expression was higher in yeast cells, when compared to mycelium and mycelium to yeast transition. Pbca1 was induced yeast cells recovery directly from liver and spleen while the transcripts for Pbca2 and Pbca4 were repressed in all condictions. The gene expression data suggest differential roles of the CAs in the fungal physiology.