XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:120-1

Poster (Painel)

120-1	Analysis of the promoter region of genes 1,3-β-glucan਀ 猀礀渀琀栀愀猀攀愀渀搀挀栀椀琀椀渀猀礀渀琀栀愀猀攀㐀漀昀倀愀爀愀挀漀挀挀椀搀椀漀椀搀攀猀戀爀愀猀椀氀椀攀渀猀椀猀戀礀䔀䴀匀䄀
Authors:	Tatiane Araujo Costa (UNB - UNIVERSIDADE DE BRASÍLIA) ; Thiago Machado Mello de Sousa (UNB - UNIVERSIDADE DE BRASÍLIA) ; Marcio Jose Poças Fonseca (UNB - UNIVERSIDADE DE BRASÍLIA) ; Ildinete Silva Pereira (UNB - UNIVERSIDADE DE BRASÍLIA)

Abstract

Paracoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis (PCM), is a thermal dimorphic fungus which grows as a mycelium at room temperature and differentiates to yeast in cultures at 37°C and in the host tissueis. The pathogenicity of the fungus appears to be linked directly to the process of dimorphic transition and cell wall changes. In P. brasiliensis, a homologous gene of 1,3-β-glucan synthase (Pbfks1) and six genes for chitin synthase (Pbchs1, Pbchs2, Pbchs3, Pbchs4, Pbchs5 and Pbchs6) were identified. In this study, we investigated the promoter region of genes Pbfks1 and Pbchs4 and by means of Electrophoretic Mobility Shift Assay (EMSA), we analyzed probes referring to the promoters of these two genes and identify likely regulatory sites. Analysis of gene promoter Pbfks1. indicates one TATA Box that can be functional and other tests performed with probes that contained a site for the transcription factors that mediates repression CreA gene in the presence of glucose and that PacC regulates gene expression in response the pH showed a specific protein-DNA interaction between the PacC domain and the recombinant protein PacC P. brasiliensis and no interaction between the transcription factor CreA and DNA binding domain of the Humicola grisea CreA. By conducting trials using the extract of mycelium of P. brasiliensis, we observed that the extract recognizes a binding domain but the results suggest that this domain is not related to sites CreA and PacC. By analyzing the promoter region of the gene Pbchs4 suggest that this gene may be being controlled by the stress response element (STRE). They also demonstrate that the DNA binding domain of PacC P. brasiliensis described recognizes a site for PacC of A. nidulans, however, the protein did not recognize a consensus sequence variation in this gene promoter Pbchs4. Since the tests performed with a probe containing a site for the transcription factor CreA demonstrated no interaction between this site and DNA binding domain of the Humicola grisea. CreA, but specific DNA-protein interactions in yeast and mycelial phases were observed. The work in our research group can contribute to understanding the regulation of gene expression promoter 1.3-β-glucan synthase and chitin synthase 4 in P. brasiliensis.

Keyword: Paracoccidioides brasiliensis, Regulation of gene expression, EMSA, Cell wall

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