Lipid Dynamics in the Golgi Apparatus

项目摘要 细胞的每个细胞器都有独特的脂质和蛋白质组成，赋予其特定的功能。而 关于介导蛋白质分选到不同细胞器的机制， 控制细胞器的脂质含量的机制在很大程度上是未知的。新的脂质合成发生在 内质网（ER），高尔基体，和神经元，然后它们被分配到其他 细胞器在协调综合的机制方面存在着巨大的知识空白 和脂质的分布。该项目中提出的研究重点是鞘磷脂，一种主要的结构 细胞膜的组成部分，以及高尔基体，其功能是“基于脂质的分选 “站”，将脂质和蛋白质散布到细胞的几乎所有细胞器。多种货物类型 运输囊泡从高尔基体出芽，人们普遍认为鞘脂等脂质的聚结 胆固醇是将货物分类到运输途径的驱动力。初步数据文件 将天然鞘磷脂结合蛋白工程改造成生物传感器， 活细胞中的鞘磷脂动力学（合成、运输）。我们将把这个新工具应用于荧光 基于显微镜的实验，以确定鞘磷脂是否富集在不同的高尔基体-质膜 运输承运人。鞘磷脂转运途径的蛋白质“客户”将通过酶促 邻近标记和蛋白质组学分析，以及这些的鞘磷脂依赖性分选机制 蛋白质将被解析。这项研究将为监管和作用提供新的见解， 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.