XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:8-1

Poster (Painel)

8-1	Gene expression analysis of the cAMP-dependent protein kinase (PKA) catalytic subunits during the morphological transition of Paracoccioidiodes brasiliensis.
Authors:	Camila Borges Mesquita (UFG - Universidade Federal de Goiás) ; Dayane Cristiny Rodrigues Araújo (UFG - Universidade Federal de Goiás) ; Juliana Parente (UFG - Universidade Federal de Goiás) ; Célia Maria de Almeida Soares (UFG - Universidade Federal de Goiás) ; Silvia Maria Salem Izacc (UFG - Universidade Federal de Goiás)

Abstract

Paracoccidioides brasiliensis, the aetiological agent of paracoccidioidomycosis (PCM), is a human pathogenic fungus that switches from a saprobic mycelium to a pathogenic yeast. Despite the great epidemiological relevance of PCM, little is known about the molecular mechanisms involved in the recognition and transmission of the signals that trigger the mycelium to yeast transition in P. brasiliensis. Several studies regarding the fungal transcriptome set up in the last few years show that different signal transduction pathways are active in P. brasiliensis, for instance: cAMP/PKA; MAP kinases; ras proteins; calmodulin-calcineurin; and the target of rapamycin. The cAMP/PKA signalling pathway is activated during the transition from mycelium to yeast in P. brasiliensis. Consistent with the morphological transition being regulated by this signalling pathway, there is an increase in cellular cAMP levels during the transition to the yeast form, and this transition can be modulated by exogenous cAMP. As described to P. Brasiliensis, the cAMP/PKA signalling pathway has been implicated in controlling morphological changes and the virulence of a number of fungi, like Candida albicans, C. neoformans and A. fumigatus. Here, we show the transcriptional profiling of P. brasiliensis PKA catalytic subunits, named PbPKAc1 and PbPKAc2, in different times of the mycelium to yeast transition. We also show an in silico analysis of the transcripts and the corresponding amino acid sequences of PbPKAc1 e PbPKAc2. Both are serine/threonine protein kinases presenting the STKC_AGC and PKc domains. The PKA catalytic subunits show high identity/similarity to the PKA of other fungi. However, only PbPKAc1 is similar to the alpha and beta subunits of human PKA. The PbPKAc1 and PbPKAc2 cDNAs were cloned in an expression vector and the interaction of these subunits with other proteins of P. brasiliensis is under investigation. This sutdies constitutes the first approach to elucidate the role of PKA in P. brasiliensis signaling process. ਀䄀瀀漀椀漀䘀椀渀愀渀挀攀椀爀漀㨀䌀一倀焀

Keyword: PKA, phase transition, P. brasiliensis

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