Saccharomyces cerevisiae Mid2p is a potential cell wall stress sensor and upstream activator of the PKC1-MPK1 cell integrity pathway
Saccharomyces cerevisiae Mid2p is a potential cell wall stress sensor and upstream activator of the PKC1-MPK1 cell integrity pathway
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DOI：
10.1128/jb.181.11.3330-3340.1999
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发表时间：
1999-06-01
影响因子：
3.2
通讯作者：
Bussey, H
中科院分区：
文献类型：
--
作者：
Ketela, T;Green, R;Bussey, H
酿酒酵母的MID2基因编码一种具有质膜相关细胞壁传感器结构特征的蛋白质。MID2是一个多拷贝的转录因子的激活子。MID2的缺失会导致对钙华白色的抗性，在各种条件下胁迫诱导的细胞壁甲壳素的产生减少，以及一些不同的细胞壁生物合成突变体的生长速度和活性的变化。MID2的过表达导致甲壳素的过度积累和对钙离子白色的敏感性增加，MID2 Delta突变体的α-因子超敏反应可以通过过表达细胞完整性途径的上游元件，包括PKC1、RHO1、WSC1和WSC2来抑制。Mid2p和Wsc1p在维持细胞完整性方面似乎有重叠的作用，因为Mid2 Delta wsc1 Delta突变体在不含渗透压支持的培养基上不能存活。MID2在细胞完整性途径中的作用进一步得到了以下发现的支持：MID2是在暴露于或-因子、钙荧光白或高温时诱导Mpk1p酪氨酸磷酸化所必需的。我们的数据与Mid2p在传感细胞壁压力和激活包括几丁质合成增加和Mpk1p丝裂原活化蛋白激酶细胞完整性通路在内的反应中的作用是一致的。此外，我们还鉴定了一个开放阅读框架MTL1，它编码的蛋白质在结构和功能上都与Mid2p相似。
The MID2 gene of Saccharomyces cerevisiae encodes a protein with structural features indicative of a plasma membrane-associated cell wall sensor. MID2 was isolated as a multicopy activator of the Skn7p transcription factor. Deletion of MID2 causes resistance to calcofluor white, diminished production of stress-induced cell wall chitin under a variety of conditions, and changes in growth rate and viability in a number of different cell wall biosynthesis mutants. Overexpression of MID2 causes hyperaccumulation of chitin and increased sensitivity to calcofluor white, alpha-Factor hypersensitivity of mid2 Delta mutants can be suppressed by overexpression of upstream elements of the cell integrity pathway, including PKC1, RHO1, WSC1, and WSC2. Mid2p and Wsc1p appear to have overlapping roles in maintaining cell integrity since mid2 Delta wsc1 Delta mutants are inviable on medium that does not contain osmotic support. A role for MID2 in the cell integrity pathway is further supported by the finding that MID2 is required for induction of Mpk1p tyrosine phosphorylation during exposure to or-factor, calcofluor white, or high temperature. Our data are consistent with a role for Mid2p in sensing cell wall stress and in activation of a response that includes both increased chitin synthesis and the Mpk1p mitogen-activated protein kinase cell integrity pathway. In addition, we have identified an open reading frame, MTL1, which encodes a protein with both structural and functional similarity to Mid2p.