Yeast Whi2 and Psr1-phosphatase form a complex and regulate STRE-mediated gene expression
Yeast Whi2 and Psr1-phosphatase form a complex and regulate STRE-mediated gene expression
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DOI：
10.1046/j.1365-2443.2002.00538.x
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发表时间：
2002-06-01
期刊：
影响因子：
2.1
通讯作者：
Kikuchi, Y
中科院分区：
文献类型：
--
作者：
Kaida, D;Yashiroda, H;Kikuchi, Y
背景：为了应对各种应激情况，包括双峰条件，Msn2 和 Msn4 转录因子诱导酿酒酵母中许多应激反应基因的 STRE 介导的基因表达。这称为一般应激反应。处于稳定期的whi2细胞比野生型细胞小。结果：在这里，我们证明在各种应激条件下，whi2细胞中STRE介导的基因表达减少至野生型细胞的一半。当突变细胞进入稳定期时，它也会延迟几个小时。利用双杂交系统，我们分离出了一个WHI2相互作用基因PSR1，它是编码质膜磷酸酶的冗余基因之一，whi2和psr1 psr2突变体具有相似的表型，包括STRE介导的基因表达减少、对钠离子和热休克的敏感性更高以及Msn2的过度磷酸化。 Psr1 的磷酸酶活性对于 STRE 介导的基因表达的完全激活是必要的。此外，Psr1 和 Msn2 均与 Whi2 共免疫沉淀。结论：因此，Whi2 及其结合伴侣 Psr1 磷酸酶是全面激活一般应激反应所必需的，可能是通过 Msn2 的去磷酸化实现的。这些结果可以解释为什么稳定期whi2 细胞很小。
Background: In response to various stressful situations, including diauxic conditions, the Msn2 and Msn4 transcription factors induce STRE-mediated gene expression of many stress responsive genes in Saccharomyces cerevisiae. This is called the general stress response. The whi2 cells in the stationary phase are smaller than wild-type cells.Results: Here we demonstrate that STRE-mediated gene expression in whi2 cells is reduced to half of that in the wild-type cells under various stress conditions. It is also delayed for several hours when the mutant cells enter the stationary phase. Using the two-hybrid system, we isolated a WHI2-interacting gene, PSR1, which is one of the redundant genes encoding plasma membrane phosphatases, whi2 and psr1 psr2 mutants had similar phenotypes, including reduced STRE-mediated gene expression, higher sensitivity to sodium ions and heat shock, and hyper-phosphorylation of Msn2. The phosphatase activity of Psr1 was necessary for the full activation of STRE-mediated gene expression. Furthermore, both Psr1 and Msn2 were co-immunoprecipitated with Whi2.Conclusions: Thus, Whi2 and its binding partner, Psr1-phosphatase, are required for a full activation of the general stress response, possibly through the dephosphorylation of Msn2. These results may explain why stationary phase whi2 cells are small.