Análise da expressão e das interações da subunidade catalítica da PKA do fungo patogênico Paracoccidioides ssp.

• Autor(a) principal: Teixeira, Mirian Vieira
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5811
• topic: Paracoccidioides; Transição dimórfica; Via cAMP/PKA; Ensaios de pull down; Paracoccidioides; Dimorphic transition; cAMP/PKA pathway; Pull-down assays; GENETICA::GENETICA HUMANA E MEDICA

The Paracoccidioides genus comprises a complex of pathogenic fungi that are the etiologic agents of paracoccidioidomycosis (PCM), the most prevalent systemic mycosis in Latin America. The infection begins after inhalation of fungal propagules, which reach the epithelium of the alveoli where the transition from the mycelial to the pathogenic yeast form. Host elevated temperature triggers the morphological switch, which is necessary for fungal pathogenicity. The cAMP/protein kinase A (PKA) signaling pathway has been shown to be important in controlling morphological changes and the pathogenicity of several pathogenic fungi. Evidence also highlights the importance of the cAMP/PKA pathway in the morphological transition of Paracoccidioides. PKA is the major effector of this signaling pathway. The protein is an inactive tetramer composed of regulatory subunit, encoded by the BCY1 gene; and catalytic subunit, encoded by the TPK2 gene. Upon binding of cAMP to the regulatory subunits, the catalytic subunits dissociate and become active. Activated PKA subsequently phosphorylates protein kinases, transcription factors, and other substrates to control several biological processes. In this study, we evaluated the expression and interactions of Tpk2 protein Paracoccididioides spp. The Tpk2 is present in mycelium decreased during the initial stages of transition phases, and increases again at the end of differentiation, with maximal levels in yeast. We analyzed the interactions of recombinant Tpk2p with Paracoccidioides proteins using pull-down assays followed by MS analysis. Two interacting proteins were identified: the heat shock protein 90 (Hsp90) and a conserved hypothetical protein with a MFS domain. Hsp90 is involved in the regulation of morphogenesis, development and virulence in several thermal dimorphic fungi. These data are important for understanding the mechanisms that trigger the transition phases in Paracoccidioides.