H<sub>2sub>O<sub>2sub> induces rapid biophysical and permeability changes in the plasma membrane of Saccharomyces cerevisiae
- 作者：V ; erlei Folmer ; Nuno Pedroso ; Ana C. Matias ; Sí ; lvia C.D.N. Lopes ; Fern ; o Antunes ; Luí ; sa Cyrne ; H. Susana Marinho
- 关键词：Hydrogen peroxide ; H<sub>2sub>O<sub>2sub> gradient ; H<sub>2sub>O<sub>2sub> adaptation ; Catalase ; Cytochrome c peroxidase ; Plasma membrane fluidity
- 刊名：Biochimica et Biophysica Acta (BBA)/Biomembranes
- 出版年：2008
- 期刊代码：14_00052736
- 类别：bio
- 出版时间：April 2008
- 卷：1778
- 期：4
- 页码：1141-1147
- 文件大小：315 K
摘要
In Saccharomyces cerevisiae, the diffusion rate of hydrogen peroxide (H<sub>2sub>O<sub>2sub>) through the plasma membrane decreases during adaptation to H<sub>2sub>O<sub>2sub> by means of a mechanism that is still unknown. Here, evidence is presented that during adaptation to H<sub>2sub>O<sub>2sub> the anisotropy of the plasma membrane increases. Adaptation to H<sub>2sub>O<sub>2sub> was studied at several times (15min up to 90min) by applying the steady-state H<sub>2sub>O<sub>2sub> delivery model. For wild-type cells, the steady-state fluorescence anisotropy increased after 30min, or 60min, when using 2-(9-anthroyloxy) stearic acid (2-AS), or diphenylhexatriene (DPH) membrane probe, respectively. Moreover, a 40%decrease in plasma membrane permeability to H<sub>2sub>O<sub>2sub> was observed at 15min with a concomitant two-fold increase in catalase activity. Disruption of the ergosterol pathway, by knocking out either ERG3 or ERG6, prevents the changes in anisotropy during H<sub>2sub>O<sub>2sub> adaptation. H<sub>2sub>O<sub>2sub> diffusion through the plasma membrane in S. cerevisiae cells is not mediated by aquaporins since the H<sub>2sub>O<sub>2sub> permeability constant is not altered in the presence of the aquaporin inhibitor mercuric chloride. Altogether, these results indicate that the regulation of the plasma membrane permeability towards H<sub>2sub>O<sub>2sub> is mediated by modulation of the biophysical properties of the plasma membrane.