A conserved dimorphism-regulating histidine kinase controls the dimorphic switching in Paracoccidioides brasiliensis.
Paracoccidioides brasiliensis and P. lutzii, thermally dimorphic fungi, are the causative agents of paracoccidioidomycosis (PCM). Paracoccidioides infection occurs when conidia or mycelium fragments are inhaled by the host, which causes the Paracoccidioides cells to transition to the yeast form. The development of disease requires conidia inside the host alveoli to differentiate into yeast cells in a temperature-dependent manner. We describe the presence of a two-component signal transduction system in P. brasiliensis, which we investigated by expression analysis of a hypothetical protein gene (PADG_07579) that showed high similarity with the dimorphism-regulating histidine kinase (DRK1) gene of Blastomyces dermatitidis and Histoplasma capsulatum This gene was sensitive to environmental redox changes, which was demonstrated by a dose-dependent decrease in transcript levels after peroxide stimulation and a subtler decrease in transcript levels after NO stimulation. Furthermore, the higher PbDRK1 levels after treatment with increasing NaCl concentrations suggest that this histidine kinase can play a role as osmosensing. In the mycelium-yeast (M→Y) transition, PbDRK1 mRNA expression increased 14-fold after 24 h incubation at 37°C, consistent with similar observations in other virulent fungi. These results demonstrate that the PbDRK1 gene is differentially expressed during the dimorphic M→Y transition. Finally, when P. brasiliensis mycelium cells were exposed to a histidine kinase inhibitor and incubated at 37°C, there was a delay in the dimorphic M→Y transition, suggesting that histidine kinases could be targets of interest for PCM therapy.
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Unidade José Alencar, Street São Nicolau, nº210, 4º floor, São Paulo 04023-900, Brazil.
Alison F A
AF
Chaves
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Unidade José Alencar, Street São Nicolau, nº210, 4º floor, São Paulo 04023-900, Brazil.
Marina V
MV
Navarro
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Unidade José Alencar, Street São Nicolau, nº210, 4º floor, São Paulo 04023-900, Brazil.
Daniele G
DG
Castilho
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Unidade José Alencar, Street São Nicolau, nº210, 4º floor, São Paulo 04023-900, Brazil.
Juliana C P
JC
Calado
Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo, Diadema 09913-030, São Paulo, Brazil.
Palloma M
PM
Conceição
Departamento de Microbiologia, Imunologia e Parasitologia, Universidade Federal de São Paulo, Unidade José Alencar, Street São Nicolau, nº210, 4º floor, São Paulo 04023-900, Brazil Departamento de Ciências Farmacêuticas, Universidade Federal de São Paulo, Diadema 09913-030, São Paulo, Brazil batista@unifesp.br.
Wagner L
WL
Batista
D015966:Gene Expression Regulation, Fungal; D000071677:Histidine Kinase / Q000378:metabolism*; D016877:Oxidants / Q000378:metabolism; D010228:Paracoccidioides / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D015398:Signal Transduction; D012965:Sodium Chloride / Q000378:metabolism; D013696:Temperature
D016877:Oxidants; D012965:Sodium Chloride; D000071677:Histidine Kinase
Paracoccidioides; dimorphism; histidine kinase; phosphorelay