H2O2 induces rapid biophysical and permeability changes in the plasma membrane of Saccharomyces cerevisiae
H2O2 induces rapid biophysical and permeability changes in the plasma membrane of Saccharomyces cerevisiae
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DOI：
10.1016/j.bbamem.2007.12.008
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发表时间：
2008-04-01
影响因子：
3.4
通讯作者：
Marinho, H. Susana
中科院分区：
文献类型：
--
作者：
Folmer, Vanderlei;Pedroso, Nuno;Marinho, H. Susana
在酿酒酵母（Saccharomyces cerevisiae）中，过氧化氢（H2O2）通过质膜的扩散速率在适应H2O2过程中降低，其机制尚不清楚。本研究表明，在适应h2o2的过程中，质膜的各向异性增加。采用稳态h2o2输送模型，研究了不同时间（15min ~ 90min）对h2o2的适应性。对于野生型细胞，分别使用2-（9-邻基氧基）硬脂酸（2- as）和二苯己三烯（DPH）膜探针，在30min和60min后，稳态荧光各向异性增加。此外，在15min时，质膜对h2o2的通透性降低40%，同时过氧化氢酶活性增加两倍。通过敲除ERG3或ERG6来破坏麦角甾醇通路，可以阻止h2o2适应过程中各向异性的变化。h2o2在酿酒酵母细胞中通过质膜的扩散不是由水通道蛋白介导的，因为在水通道蛋白抑制剂氯化汞的存在下，h2o2的渗透常数没有改变。综上所述，这些结果表明，质膜对h2o2的通透性调节是通过调节质膜的生物物理性质来实现的。
In Saccharomyces cerevisiae, the diffusion rate of hydrogen peroxide (H2O2) through the plasma membrane decreases during adaptation to H2O2by means of a mechanism that is still unknown. Here, evidence is presented that during adaptation to H2O2the anisotropy of the plasma membrane increases. Adaptation to H2O2was studied at several times (15min up to 90min) by applying the steady-state H2O2delivery 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 H2O2was 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 H2O2adaptation. H2O2diffusion through the plasma membrane in S. cerevisiae cells is not mediated by aquaporins since the H2O2permeability 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 H2O2is mediated by modulation of the biophysical properties of the plasma membrane.