Regulation of Ceramide Synthase by Protein-Protein Interaction

标题：蛋白质-蛋白质相互作用对神经酰胺合成酶的调节 摘要： 神经酰胺是所有鞘糖脂的主干，神经酰胺合成酶(CERs)是关键酶。 用于神经酰胺的从头生产。尽管CERs在神经酰胺的产生中起着关键作用，但有一个严重的 对这些酶是如何调节的缺乏了解。这个项目的长期目标是发现 并了解CERs酶如何受到调控的基本分子机制。使用 通过蛋白质组学的方法，我们发现小分子热休克蛋白Hsp27与CerS1特异地相互作用。 基于我们的初步数据，我们产生了新的假设，即Hsp27是CerS1的负调控因子 通过p38-MK2 MAPK介导的Hsp27磷酸化调节的直接相互作用的活性，以及 Hsp27的下调可诱导CerS1/C18：0神经酰胺介导的细胞反应。为了测试这一点 假设，我们提出以下具体目标：目标1：确定Hsp27的生物化学意义 调节神经鞘脂脂代谢和信号转导的CerS1基因。目标2：定义 Hsp27介导的CerS1调控的生物学意义目的3：确定Hsp27的作用机制 CerS1蛋白与蛋白质的相互作用。总体而言，这些研究将确定Hsp27是一种内源性调节因子 CerS1，揭示了Hsp27调控CerS1和CerS1/C18的新机制：0-神经酰胺 有丝分裂和癌细胞死亡。本研究所产生的知识将有助于基于机构的设计 抗癌和其他病理的新疗法，其中C18：0-神经酰胺是关键的介质，通过识别 调节CerS1活性的新方法。

Title: REGULATION OF CERAMIDE SYNTHASE BY PROTEIN-PROTEIN INTERACTION Abstract: Ceramides form the backbone of all sphingolipids, and ceramide synthases (CerS) are critical enzymes for de novo production of ceramides. In spite of the key role of CerS in ceramide generation, there is a serious deficiency in understanding how these enzymes are regulated. The long-term goal of this project is to uncover and understand the fundamental molecular mechanisms of how CerS enzymes are regulated. Using a proteomics approach, we discovered that the small heat shock protein Hsp27 interacts specifically with CerS1. Based on our preliminary data we generated the novel hypothesis that Hsp27 is a negative regulator of CerS1 activity via direct interaction that can be modulated by p38-MK2 MAPK mediated phosphorylation of Hsp27, and that down-regulation of Hsp27 induces CerS1/C18:0-ceramide mediated cellular responses. To test this hypothesis, we propose the following Specific Aims: Aim 1: Define the biochemical significance of Hsp27 mediated CerS1 regulation in cells with respect to sphingolipid metabolism and signal transduction. Aim 2: Define the biological significance of Hsp27 mediated CerS1 regulation. Aim 3: Determine the mechanism of Hsp27- CerS1 protein-protein interaction. Overall, these studies will establish Hsp27 as an endogenous modulator of CerS1 and uncover a novel mechanism of how Hsp27 regulates CerS1 and CerS1/C18:0-ceramide governed mitophagy and cancer cell death. The knowledge generated from this study will help design mechanism-based novel therapies against cancer and other pathologies in which C18:0-ceramide is the key mediator by identifying new methods to modulate CerS1 activity.