Activation of the HOG pathway upon cold stress in Saccharomyces cerevisiae
Activation of the HOG pathway upon cold stress in Saccharomyces cerevisiae
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DOI：
10.1093/jb/mvj089
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发表时间：
2006-04-01
影响因子：
2.7
通讯作者：
Maeda, Tatsuya
中科院分区：
文献类型：
--
作者：
Hayashi, Michio;Maeda, Tatsuya
当酿酒酵母细胞暴露于高渗透胁迫时，高渗透压甘油反应（high- osmoarity glycerol response， HOG）通路被激活，诱导渗透反应。HOG途径包括两个上游渗透传感分支，SLN1和SHO1分支，以及下游MAP激酶级联。尽管这些上游分支向MAP激酶级联传递信号的机制已被很好地理解，但它们感知和响应渗透变化的机制尚不清楚。本研究表明，当细胞暴露于冷应激（0℃处理）时，HOG通路以SLN1分支依赖的方式被激活。二甲亚砜（DMSO）处理，使细胞膜硬化，也以SLN1分支和SHO1分支依赖的方式激活HOG途径。此外，冷胁迫和高渗胁迫与DMSO处理对HOG通路的激活表现出协同效应。另一方面，乙醇处理使细胞膜流化，部分抑制了冷应激诱导的HOG通路激活。我们的研究结果表明，这两个渗透传感分支响应细胞膜的硬化来激活HOG途径。
When Saccharomyces cerevisiae cells are exposed to hyper-osmotic stress, the high-osmolarity glycerol response (HOG) pathway is activated to induce osmotic responses. The HOG pathway consists of two upstream osmosensing branches, the SLN1 and SHO1 branches, and a downstream MAP kinase cascade. Although the mechanisms by which these upstream branches transmit signals to the MAP kinase cascade are well understood, the mechanisms by which they sense and respond to osmotic changes are elusive. Here we show that the HOG pathway is activated in an SLN1 branch-dependent manner when cells are exposed to cold stress (0 degrees C treatment). Dimethyl sulfoxide (DMSO) treatment, which rigidifies the cell membrane, also activates the HOG pathway in both SLN1 branch- and SHO1 branch-dependent manners. Moreover, cold stress, as well as hyperosmotic stress, exhibits a synergistic effect with DMSO treatment on HOG pathway activation. On the other hand, ethanol treatment, which fluidizes the cell membrane, partially represses the cold stress-induced HOG pathway activation. Our results suggest that both osmosensing branches respond to the rigidification of the cell membrane to activate the HOG pathway.