Department of Chemistry, Umeå University, Sweden.
BMC Genomics. 2012 Jun 9;13:230. doi: 10.1186/1471-2164-13-230.
The activity of the yeast activator protein 1 (Yap1p) increases under stress conditions, which leads to enhanced transcription of a number of genes encoding protective enzymes or other proteins. To obtain a global overview of changes in expression of Yap1p-targeted proteins, we compared a Yap1p-overexpressing transformant with a control transformant by triplicate analysis of the proteome using two-dimensional gel electrophoresis (2-DE). Proteins of interest were identified using MALDI-MS or LC-MS/MS.
The relative quantities of 55 proteins were elevated significantly upon overexpression of Yap1p, and most of these proteins were found to have a Yap1p-binding site upstream of their coding sequences. Interestingly, the main metabolic enzymes in the glycolysis and pyruvate-ethanol pathways showed a significant increase in the Yap1p-overexpressing transformant. Moreover, a comparison of our proteome data with transcriptome data from the literature suggested which proteins were regulated at the level of the proteome, and which proteins were regulated at the level of the transcriptome. Eight proteins involved in stress response, including seven heat-shock and chaperone proteins, were significantly more abundant in the Yap1p-overexpressing transformant.
We have investigated the general protein composition in Yap1p-overexpressing S. cerevisiae using proteomic techniques, and quantified the changes in the expression of the potential Yap1p-targeted proteins. Identification of the potential Yap1p targets and analysis of their role in cellular processes not only give a global overview of the ubiquitous cellular changes elicited by Yap1p, but also provide the framework for understanding the mechanisms behind Yap1p-regulated stress response in yeast.
在应激条件下，酵母激活蛋白 1（Yap1p）的活性增加，导致许多编码保护性酶或其他蛋白质的基因的转录增强。为了获得 Yap1p 靶向蛋白表达变化的全局概述，我们通过使用二维凝胶电泳（2-DE）对蛋白质组进行三次重复分析，比较了 Yap1p 过表达转化体和对照转化体。使用 MALDI-MS 或 LC-MS/MS 鉴定感兴趣的蛋白质。
过表达 yap1p 后，有 55 种蛋白质的相对丰度显著升高，其中大多数蛋白质在其编码序列的上游具有 yap1p 结合位点。有趣的是，糖酵解和丙酮酸-乙醇途径中的主要代谢酶在 yap1p 过表达转化体中显著增加。此外，将我们的蛋白质组数据与文献中的转录组数据进行比较表明，哪些蛋白质在蛋白质组水平受到调节，哪些蛋白质在转录组水平受到调节。参与应激反应的 8 种蛋白质，包括 7 种热休克和伴侣蛋白，在 yap1p 过表达转化体中明显更为丰富。
我们使用蛋白质组学技术研究了 yap1p 过表达 S. cerevisiae 中的一般蛋白质组成，并定量分析了潜在 yap1p 靶向蛋白表达的变化。鉴定潜在的 yap1p 靶标并分析它们在细胞过程中的作用，不仅提供了 yap1p 诱导的普遍细胞变化的全局概述，而且为理解酵母中 yap1p 调节的应激反应背后的机制提供了框架。
