过氧化氢诱导酿酒酵母细胞膜透性和组成的变化

H2O2 induces changes in the plasma membrane of Saccharomyces cerevisiae

摘要:

以下简述了过氧化氢(H2O2)作为一种信号分子诱导并调节酿酒酵母(Saccharomyces cerevisiae)细胞膜的变化。h2o2是一种强氧化剂, 可以跨膜扩散进入细胞中, 形成跨膜梯度; 当外源H2O2达到亚致死剂量时, 酿酒酵母的细胞膜透性和流动性降低, 产生跨膜梯度, 从而限制H2O2向细胞内的扩散速率, 保护细胞免受氧化胁迫的伤害。研究表明, 由H2O2引起的膜透性和流动性的变化与膜的组成有关: 当酵母细胞对H2O2产生适应时, 与膜组成和微区域变化有关的几个基因的表达发生了改变。膜组成的变化和微区域的调整还可能与H2O2依赖的信号途径有关, 即以H2O2为信号分子, 调节膜的变化并赋予细胞对氧化压力更高的适应性, 但这种信号分子的具体传递途径及机制还需要进一步研究。

关键词:过氧化氢, 酿酒酵母, 膜透性, 膜流动性, 膜组成, 适应性

Abstract:

This article reviews the recent studies on h2o2 adaptation of Saccharomyces cerevisiae. When the cell exposed in the h2o2 sub-lethal doses, the plasma membrane permeability decreased, meanwhile the plasma membrane fluidity is minished. These changes resulted in a gradient across the plasma membrane, which conferring a higher resistance to oxidative stress. Recent work has also shown that the yeast cells adapted to H2O2 would lead to several changes in the expression of genes coding the key enzymes involved in the biosynthesis of lipid profile and in the organization of lipid microdomains of the plasma membrane, which finally decreased its’ permeability and fluidity. The reorganization of the plasma membrane might be the major mechanism of the h2o2 adaptation. Once the yeast cells adapted to the external h2o2, changes in plasma occurred. The h2o2 dependent signaling pathways in the plasma membrane might be activated by high levels of h2o2. But the details of the signaling events should still be further studies.

Key words:hydrogen peroxide (H2O2), Saccharomyces cerevisiae, plasma membrane permeability, plasma membrane fluidity, plasma membrane composition, adaptation