Identifying the mechanisms and biological impact of ERK lipidation in metabolic signaling

项目摘要/摘要 在细胞水平上，受损的信号级联既是代谢综合征的原因，也是代谢综合征的特征， 一系列相互关联的疾病，包括高脂血症和高血糖。然而，这些机制 发病机制是复杂的，多因素的，并且不完全被描述。最近的研究表明， 蛋白质S-棕榈酰化，一种影响蛋白质功能和蛋白质功能的动态脂质翻译后修饰 活动，在代谢信号事件的调节中。因为将棕榈酸酯类脂添加到半胱氨酸中 依赖于脂类水平--在代谢综合征中脂类水平会发生变化--蛋白质脂化代表着一种 营养因子异常与信号蛋白活性变化之间潜在的机制联系。我们有 观察到细胞外信号调节激酶(ERK)，其信号反应活性调节 细胞代谢/能量动态平衡在代谢综合征中发生改变，受到快速、信号- 诱导棕榈酰化的增加。此外，ERK棕榈酰化的基础水平在小鼠中增加 肥胖模型，证实其脂肪代谢状态对饮食敏感。在这个项目中，以ERK为焦点 ，我们的目标是绘制调节性S棕榈酰化、信号转导和后遗症之间的联系 新陈代谢综合症。在目标1中，我们将使用分子生物学、生化和化学的组合 确定ERK棕榈酰化的分子机制并阐明其影响的方法 ERK介导的信号转导中的动态S棕榈酰化。为了评估增加的贡献 ERK棕榈酰化为代谢综合征，在目的2我们将开发一种ERK的化学抑制剂S-棕榈酰化。 然后，我们将把它应用于代谢综合征的小鼠模型，评估ERK活性和 减轻代谢综合征的标志物，包括胰岛素抵抗和循环脂肪酸水平。这 这项工作将为ERK建立一个新的监管框架，以及探测 其活动的机制和后果。它还将提供一个模型，说明动态蛋白质脂肪化如何 在细胞信号事件中发挥作用，并对细胞的病理生理做出贡献。 好了！

Project Summary/Abstract At the cellular level, impaired signaling cascades both contribute to and are characteristic of metabolic syndrome, a constellation of interrelated disorders including hyperlipidemia and hyperglycemia. However, the mechanisms of pathogenesis are complex, multifactorial, and incompletely described. Recent studies suggest a role for protein S-palmitoylation, a dynamic lipid post-translational modification (PTM) that affects protein function and activity, in the regulation of metabolic signaling events. As the addition of the palmitate lipid to cysteine is dependent on lipid levels – which are in turn altered in metabolic syndrome – protein lipidation represents a potential mechanistic link between aberrant nutrient factors and changes in signaling protein activity. We have observed that the extracellular signal-regulated kinase (ERK), whose signaling-responsive activity regulates cellular metabolism/energy homeostasis and is altered in metabolic syndrome, is subject to a rapid, signaling- induced increase in palmitoylation. Moreover, the basal level of ERK palmitoylation is increased in a mouse model of obesity, confirming that its lipidation status is sensitive to diet. In this project, with ERK as the focal point, we aim to map the connections between regulatory S-palmitoylation, signal transduction, and the sequelae of metabolic syndrome. In Aim 1, we will use a combination of molecular biological, biochemical, and chemical approaches to determine the molecular mechanisms of ERK palmitoylation and to elucidate the impact of dynamic S-palmitoylation on ERK-mediated signal transduction. In order to assess the contribution of increased ERK palmitoylation to metabolic syndrome, in Aim 2 we will develop a chemical inhibitor of ERK S-palmitoylation. We will then employ it in a mouse model of metabolic syndrome, evaluating changes in ERK activity and the mitigation of markers of metabolic syndrome, including insulin resistance and circulating fatty acid levels. This work will establish a novel regulatory framework for ERK, as well as new chemical tools for probing the mechanisms and consequences of its activity. It will also provide a model for how dynamic protein lipidation can function in cell signaling events and contribute to cellular pathophysiologies. !