Mechanism and physiology of DUF1222-assisted lipase maturation

描述： 脂蛋白脂肪酶(LPL)对三酰甘油的降解是维持正常血脂所必需的 新陈代谢。LPL在没有新识别的情况下不能正常折叠和工作， 跨膜蛋白，脂肪酶成熟因子(LMF1)。LMF1本质上是 没有特征；事实上，它属于一个蛋白质家族，具有类似的“结构域 未知的功能“(Duf1222)。这个项目的主要目标是研究 LPL和LMF1之间的相互作用。类比于具有结构特征的脂肪酶 与LPL相似，我们认为LMF1是LPL的“专用折叠酶”。在《目标1》中，我将 使用生化分析和细胞中的分析来确定为什么LPL需要折叠 以及LMF1如何帮助LPL折叠。目标2包括对膜的分析 LMF1的拓扑结构。最后，目标3侧重于观察到许多 人类病原体具有Duf1222蛋白；因此，我将使用计算和 用生物化学方法确定Duf1222蛋白是否代表 折叠酶-脂肪酶对。在指导阶段，我将在我的初步工作基础上 建立了LMF1膜拓扑结构的模型。另外，我将开始 LMF-LPL相互作用的生化和结构分析，并开始初步 目标3。对于独立阶段，我将继续LMF1的结构分析 并将我的生化分析扩展到其他物种的Duf1222蛋白质，以确定 它们在脂质代谢中起着重要作用。

Description: Hydrolysis of triacylglycerols by lipoprotein lipase (LPL) is essential for normal lipid metabolism. LPL does not fold and function properly without a newly identified, transmembrane protein, lipase maturation factor (LMF1). LMF1 is essentially uncharacterized; in fact it belongs to a family of proteins with a similar "domain of unknown function" (Duf1222). The major goal of this project is to investigate the interaction between LPL and LMF1. By analogy to lipases with structural characteristics similar to LPL, we propose that LMF1 acts as a "private foldase" for LPL. In Aim 1, I will use biochemical assays and assays in cells to determine why LPL needs folding assistance and how LMF1 helps LPL fold. Aim 2 consists of analysis of the membrane topology and structure of LMF1. Finally, Aim 3 focuses on the observation that many human pathogens have Duf1222 proteins; therefore I will use computational and biochemical approaches to determine if the Duf1222 protein represents one-half of a foldase-lipase pair. During the mentored phase, I will build on my preliminary observations to develop a model for LMF1 membrane topology. Additionally I will begin biochemical and structural analyses of the LMF-LPL interaction, and begin preliminary work on aim 3. For the independent phase, I will continue structural analysis of LMF1 and expand my biochemical analysis to Duf1222 proteins in other species to determine if they have important roles in lipid metabolism.