Chagas Ronney Fernandes, Bailão Alexandre Melo, Pereira Maristela, Winters Michael S, Smullian Alan George, Deepe George S, de Almeida Soares Célia Maria
Laboratório de Biologia Molecular, Instituto de Ciências Biológicas, Campus II, Universidade Federal de Goiás, 74001-970 Goiânia, Goiás, Brazil.
Fungal Genet Biol. 2008 Nov;45(11):1470-8. doi: 10.1016/j.fgb.2008.08.007. Epub 2008 Aug 30.
Paracoccidioides brasiliensis is a fungal pathogen of humans. The P. brasiliensis response to oxidative stress is largely unexplored. We report the analysis of three catalases, PbCatA, PbCatP and PbCatC. The former are monofunctional catalases and the latter is a catalase-peroxidase. Differential expression of catalases as measured by activity and by quantitative analysis of transcripts was observed in the morphological conversion and in response to different stress conditions. PbCatA manifested higher activity in the mycelial phase, showed increased activity during transition from mycelium to yeast and during conditions of endogenous oxidative stress. Consistent with our previous studies, PbCatP manifested higher activity in yeast cells since it is putatively involved in the control of exogenous reactive oxygen species. P. brasiliensis displays an oxidative stress response following phagocytosis by macrophages, inducing the expression of catalase A and P transcripts. PbCatC displayed a relatively constant pattern of expression, being modestly induced in cells exposed to osmotic and heat stress.
巴西副球孢子菌是一种人类真菌病原体。巴西副球孢子菌对氧化应激的反应在很大程度上尚未得到探索。我们报告了对三种过氧化氢酶PbCatA、PbCatP和PbCatC的分析。前两者是单功能过氧化氢酶，后者是一种过氧化氢酶-过氧化物酶。通过活性以及转录本的定量分析测量，在形态转化和对不同应激条件的反应中观察到了过氧化氢酶的差异表达。PbCatA在菌丝体阶段表现出较高的活性，在从菌丝体向酵母转变期间以及内源性氧化应激条件下活性增加。与我们之前的研究一致，PbCatP在酵母细胞中表现出较高的活性，因为它可能参与对外源活性氧的控制。巴西副球孢子菌在被巨噬细胞吞噬后表现出氧化应激反应，诱导过氧化氢酶A和P转录本的表达。PbCatC表现出相对恒定的表达模式，在暴露于渗透和热应激的细胞中受到适度诱导。
