Lipid Dynamics in the Golgi Apparatus

项目摘要 细胞的每个细胞器都有独特的脂类和蛋白质组成，赋予其特定的功能。而当 关于调节蛋白质分选到不同细胞器的机制，已经学到了很多 控制细胞器脂质含量的机制在很大程度上是未知的。新的脂肪合成发生在 内质网(ER)、高尔基体和线粒体，然后它们被分配给 细胞器。在协调合成的机制方面存在着巨大的知识空白 和脂类的分布。本项目提出的研究重点是鞘磷脂，一种主要的结构蛋白。 细胞膜的组成部分，以及高尔基体，起到“基于脂质的分类”的作用 将脂类和蛋白质散布到细胞几乎所有细胞器的“站”。多种类型的货物 从高尔基体运输囊泡发芽，人们普遍认为神经鞘脂脂等脂类的结合 而胆固醇是将货物分拣到运输路径的驱动力。初步数据文件 将天然的鞘磷脂结合蛋白改造成生物传感器，使其能够分析 活细胞中的鞘磷脂动力学(合成、运输)。我们将把这一新工具应用于荧光 基于显微镜的实验确定鞘磷脂是否在不同的高尔基体质膜上富含 运输公司。鞘磷脂运输途径的蛋白质“客户”将使用酶来鉴定 邻近标记和蛋白质组学分析，以及神经鞘蛋白依赖的分选机制 蛋白质将会被阐明。这项研究将为监管和发挥作用提供新的见解 细胞内的鞘磷脂。

Project Summary Each organelle of the cell has a unique lipid and protein composition that confers its specific functions. While much has been learned regarding the mechanisms that mediate sorting of proteins to different organelles, the mechanisms that govern the lipid content of organelles are largely unknown. New lipid synthesis occurs in the endoplasmic reticulum (ER), the Golgi apparatus, and the mitochondrion, and they are then distributed to other organelles. There are expansive gaps in knowledge regarding the mechanisms that coordinate the synthesis and distributions of lipids. The research proposed in this project focuses on sphingomyelin, a major structural component of the cellular membranes, and the Golgi apparatus, which functions as a “lipid based sorting station” that disseminates lipids and proteins to nearly all organelles of the cell. Multiple types of cargo transport vesicles bud from the Golgi and it is widely thought that coalescence of lipids such as sphingolipids and cholesterol is a driving force for sorting of cargos into to transport pathways. Preliminary data document the engineering of a natural sphingomyelin-binding protein into a biosensor that enables analyses of sphingomyelin dynamics (synthesis, trafficking) in living cells. We will apply this new tool in fluorescence microscopy-based experiments to determine if sphingomyelin is enriched in distinct Golgi-to-plasma membrane transport carriers. Protein ‘clients’ of the sphingomyelin transport pathway will be identified using enzymatic proximity labeling and proteomic analyses, and sphingomyelin-dependent sorting mechanisms for these proteins will be elucidated. The research will provide new insights into the regulation and roles of sphingomyelin within the cell.