Regulation of O-GlcNAcylation During Injury

总结 O-连接的β-N-乙酰葡糖胺（O-GlcNAc）对细胞内蛋白质的修饰已经成为一种新的研究热点。 新型细胞保护调节剂1 -4。多种形式的细胞损伤，包括心脏缺血预处理 （急性、长期和远程），导致体内和体外模型中O-GlcNAc水平升高。升降 在诱导细胞损伤之前或之后立即进行O-GlcNAc化在缺血模型中具有保护作用 再灌注（I/R）损伤，以及热应激、氧化应激、内质网应激、缺氧和 trauma veterinary 2，5-8.总之，这些数据表明O-GlcNAc是一种新的内源性心脏保护剂， 剂迄今为止，研究I/R损伤模型中O-GlcNAc修饰的大多数工作集中在 鉴定O-GlcNAc介导心脏保护作用的蛋白质和机制3，4。然而，在这方面， 理解损伤过程中O-GlcNAc修饰的调节是关键的，但尚未研究。目标 这项建议的一个重要目的是绘制循环O-GlcNAc修饰的酶的调控网络， GlcNAc转移酶（OGT）和O-GlcNAc酶（OGA）。具体而言，我们将完成以下目标： 目标1。定义蛋白质-蛋白质相互作用对OGT和OGA活性和底物靶向的影响 在受伤的心。定量质谱法将用于鉴定OGT的蛋白质相互作用物 和OGA。生物化学方法的组合将被用来询问这些效应器的作用， 蛋白质对缺血心脏中O-GlcNAc循环的影响。 目标二。绘制受损心脏中的OGT和OGA共价调节网络。O-GlcNAc OGT和OGA的修饰位点和其他共价调节剂将被鉴定。O的影响- 将在氧化应激和I/R损伤模型中评估GlcNAc化对OGT/OGA功能的影响。 总的来说，我们预计这些研究将确定调节OGT，OGA和O- I/R损伤期间的GlcNAc酰化。这一重要的见解将为研究新的治疗方法提供一个框架。 心肌梗死的靶点，并了解O-GlcNAc介导的应激反应是如何 调节异常导致心血管疾病

Summary The modification of intracellular proteins by O-linked β-N-acetylglucosamine (O-GlcNAc) has emerged as a novel regulator of cytoprotection1-4. Numerous forms of cellular injury, including cardiac ischemic preconditioning (acute, prolonged, and remote), lead to elevated levels of O-GlcNAc in both in vivo and in vitro models. Elevating O-GlcNAcylation before, or immediately after, the induction of cellular injury is protective in models of ischemia reperfusion (I/R) injury, as well as heat stress, oxidative stress, endoplasmic reticulum stress, hypoxia, and trauma hemorrhage2,5-8. Together, these data suggest that O-GlcNAc is a novel endogenous cardioprotective agent. To date, the majority of work studying the O-GlcNAc modification in models of I/R injury has focused on identifying the proteins and mechanisms by which O-GlcNAc mediates cardioprotection3,4. However, understanding the regulation of the O-GlcNAc modification during injury is critical and is yet unstudied. The goal of this proposal is to map the regulatory networks of the enzymes that cycle the O-GlcNAc modification, the O- GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Specifically, we will complete the following aims: Aim 1. Define the impact of protein-protein interactions on OGT and OGA activity and substrate targeting in the injured heart. Quantitative mass spectrometry will be used to identify protein-interactors of OGT and OGA. A combination of biochemical approaches will be used to interrogate the role of these effector- proteins on O-GlcNAc cycling in the ischemic heart. Aim 2. Map the OGT and OGA covalent-regulatory networks in the injured heart. The O-GlcNAc modification sites, and other covalent-regulators, of OGT and OGA will be identified. The impact of O- GlcNAcylation on OGT/OGA function will be assessed in models of oxidative stress and I/R injury. Collectively, we anticipate that these studies will define the pathways that regulate OGT, OGA, and O- GlcNAcylation during I/R injury. This critical insight will provide a framework for investigating novel therapeutic targets for myocardial infarction and an understanding about how the O-GlcNAc-mediated stress response is dysregulated contributing to cardiovascular disease