Phase transition and stage-specific protein synthesis in the dimorphic fungus Paracoccidioides brasiliensis

Morphological and molecular aspects of the dimorphic pathogenic fungus Paracoccidioides brasiliensis, strain Pb 01, were investigated in vitro. Morphological alterations during temperature shifts were preceded by significant changes in protein synthesis during the yeast → mycelium (36°C → 26°C) transition. The reverse process, mycelium → yeast differentiation (26°C → 36°C) is characterized by alterations in the synthesis of few proteins. We have also reported the occurrence of some stage-specific proteins in both yeast and mycelium forms; the classical heat shock protein hsp70 is detected only in yeast cells. The dimorphic characteristics of P. brasiliensis make it an attractive model for gene expression and cellular differentiation studies.