Tryptophan permease gene TAT2 confers high-pressure growth in Saccharomyces cerevisiae
Tryptophan permease gene TAT2 confers high-pressure growth in Saccharomyces cerevisiae
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DOI：
10.1128/mcb.20.21.8093-8102.2000
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发表时间：
2000-11-01
影响因子：
5.3
通讯作者：
Horikoshi, K
中科院分区：
文献类型：
--
作者：
Abe, F;Horikoshi, K
发现在15至25 MPa范围内的静水压力导致酿酒酵母的指数生长培养物中的细胞周期停滞在G（1）期，而50 MPa的压力则没有。Ne发现，携带TAT 2基因的质粒（该基因编码高亲和力色氨酸通透酶）使细胞能够在15至25 MPa的压力条件下生长。此外，高水平表达Tat 2蛋白的细胞被赋予了在10或15摄氏度的低温条件下以及在高压下生长的能力。静水压力显著抑制色氨酸摄入细胞，Tat 2蛋白水平下调高压。发现与色氨酸摄取相关的活化体积是一个大的正值，46.2 +/- 3.85 ml/mol，表明在色氨酸输入的限速步骤中存在净体积增加。显示细胞周期停滞在G（1）期和Tat 2蛋白的去调节的结果似乎与用免疫抑制药物雷帕霉素处理细胞时观察到的结果相似。虽然雷帕霉素处理引起Npr 1的快速去磷酸化和诱导Gap 1的表达，静水压力并不影响Npr 1的磷酸化状态，它降低了Gap 1蛋白的水平，这表明压力传感途径可能是独立的Npr 1功能。在这里，我们描述了高压传感在酵母中的TOR信号通路的比较，并讨论了一个重要的因素参与适应生物体的高压环境。
Hydrostatic pressure in the range of 15 to 25 MPa was found to cause arrest of the cell cycle in G(1) phase in an exponentially growing culture of Saccharomyces cerevisiae, whereas a pressure of 50 MPa did not. Ne found that a plasmid carrying the TAT2 gene, which encodes a high-affinity tryptophan permease, enabled the cells to grow under conditions of pressure in the range of 15 to 25 MPa. Additionally, cells expressing the Tat2 protein at high levels became endowed with the ability to grow under low-temperature conditions at 10 or 15 degrees C as well as at high pressure. Hydrostatic pressure significantly inhibited tryptophan uptake into the cells, and the Tat2 protein level was down-regulated by high pressure. The activation volume associated with tryptophan uptake was found to be a large positive value, 46.2 +/- 3.85 ml/mol, indicating that there was a net volume increase in a rate-limiting step in tryptophan import. The results showing cell cycle arrest in G(1) phase and dean-regulation of the Tat2 protein seem to be similar to those observed upon treatment of cells with the immunosuppressive drug rapamycin. Although rapamycin treatment elicited the rapid dephosphorylation of Npr1 and induction of Gap1 expression, hydrostatic pressure did not affect the phosphorylation state of Npr1 and it decreased the level of Gap1 protein, suggesting that the pressure sensing pathway may be independent of Npr1 function. Here we describe high-pressure sensing in yeast in comparison with the TOR-signaling pathway and discuss an important factor involved in adaptation of organisms to high-pressure environments.