The SMYD lysine methyltransferase Set6 in signaling and proteostasis

项目摘要 蛋白质稳态，或蛋白质稳态，是通过一个调节网络的翻译， 机器，分子伴侣和蛋白质降解因子，其功能是维持细胞的功能。 大量的细胞蛋白质处于折叠、可溶、非聚集状态。恶化 蛋白质稳态网络是衰老细胞的标志，并且是许多相关疾病的基础。 随着年龄的增长。蛋白质稳态网络中调节因子的一个关键机制是它们的后作用 翻译修饰，包括赖氨酸残基的甲基化。赖氨酸的SMYD家族 甲基转移酶已经显示在不同的系统中与分子伴侣相互作用， 有许多报道的赖氨酸甲基化位点的因素，有助于 蛋白质稳态然而，我们对SMYD靶向的甲基赖氨酸底物的了解 甲基转移酶及其与蛋白质稳态网络的功能相互作用仍然非常重要。 有限公司拟议工作的主要目标是利用蛋白质组学和分子工具 在模型系统Saccharomycescereviasie中定义酵母SMYD的底物 Set6酶，一种很大程度上未表征的蛋白质，并确定其在调节 蛋白质稳态网络在目标I中，我们将使用高分辨率质谱法来识别 靶向Set6蛋白质组，并进行赖氨酸的分子和生物化学表征 新发现的底物上的甲基化。在Aim II中，我们将使用分子和遗传工具 定义Set6在与蛋白质稳态网络相互作用和调节蛋白质稳态网络中的作用， 未折叠蛋白质的积累。总的来说，这项工作将整合蛋白质组学和遗传分析 为了促进我们对SMYD家族赖氨酸之间的机制联系的理解， 甲基转移酶和分子伴侣。我们希望这项工作能为以下方面提供新的见解： 调节机制的关键蛋白质，这可能揭示了新的目标， 对与蛋白质错误折叠和聚集相关的疾病的治疗干预。 此外，这些研究还将开发一个良好表征的遗传模型系统， 剖析SMYD酶促进蛋白质稳定的分子机制， 确定它们的操作如何防止与衰老相关的病理。

PROJECT SUMMARY Protein homeostasis, or proteostasis, is achieved through a regulated network of the translational machinery, molecular chaperones, and protein degradation factors, which function to maintain the abundance of the cell’s proteins in folded, soluble, non-aggregated states. Deterioration of the proteostasis network is a hallmark of aging cells and underlies numerous diseases associated with aging. A key mechanism regulating factors within the proteostasis network is their post- translational modification, including methylation at lysine residues. The SMYD family of lysine methyltransferases has been shown to interact with molecular chaperones in diverse systems, and there are numerous reported lysine methylation sites on factors that contribute to proteostasis. However, our knowledge of the methyl-lysine substrates targeted by SMYD methyltransferases and their functional interactions with the proteostasis network is still very limited. The primary objective of the proposed work is to leverage proteomic and molecular tools in the model system Saccharomyces cereviasie to define the substrates for the yeast SMYD enzyme Set6, a largely uncharacterized protein, and determine its molecular function in regulating the proteostasis network. In Aim I, we will use high-resolution mass spectrometry to identify targets of Set6 proteome-wide and perform molecular and biochemical characterization of lysine methylation on the newly-identified substrates. In Aim II, we will use molecular and genetic tools to define the role of Set6 in interacting with and regulating the proteostasis network to prevent the accumulation of unfolded proteins. In total, this work will integrate proteomic and genetic analyses to advance our understanding of the mechanistic links between the SMYD family lysine methyltransferases and molecular chaperones. We expect this work to provide new insights into regulatory mechanisms critical to proteostasis, which may shed light on new targets for therapeutic interventions into diseases associated with protein misfolding and aggregation. Furthermore, these studies will also develop a well-characterized, genetic model system for dissecting the molecular mechanisms by which SMYD enzymes contribute to proteostasis and determining how their manipulation may prevent aging-associated pathologies.