LIPID & PROTEIN TRAFFIC & DYNAMICS IN EPITHELIAL CELLS

这个项目的目的是了解和定义一些途径， 在分类、交通和定位中涉及的机制和信号 膜脂质和蛋白质到它们的功能表面结构域， 极化上皮细胞 由4个机构提供服务的6个高度相关的项目 核心单元将解决和比较分子靶向和 在各种极化上皮细胞中的定位[MDCK（肾 小管上皮）、Caco-2和HT-29（肠上皮）和WIF 12 -1 （肝细胞）]。 这些项目涉及：1）横向 膜蛋白的组织和这种组织在 新合成蛋白质的分类和定位。 2)的氨基酸 序列参与决定顶端的分布 （二肽基肽酶-IV）和基底外侧（Na，K-ATP酶）蛋白以及 蛋白质（LEP-100）在溶酶体和质膜之间循环， 核内体 这些蛋白质的细胞内转运差异 还将比较上皮细胞。 (3)分子和囊泡运输 在不同的上皮细胞类型中， 由脂质代谢或微管结构的变化引起。 该项目将包括新衍生的肝细胞系的工作 WIF12-1 4)顺式和反式高尔基体的分离与鉴定 复杂的膜作为细胞类型和极性程度的函数。 第五章） 脂质的分布和运输。 将特别强调 对荧光鞘脂类似物沿着分泌运动的影响 细胞鞘脂的改变和 胆固醇可能对脂质的分选和运输有影响。 6)本组织 微管，生物合成和内吞囊泡运输的途径 以及这种运输所需的机械酶。 这六个项目将得到细胞培养、电子 显微镜和其他成像，分子的荧光测量 行为和管理。 结构、中央支助和资源 这里提出的将导致高度协作和互动 极性建立和维持问题的探讨 的上皮细胞。

This program project aims to understand and define some of the pathways, mechanisms and signals involved in the sorting, traffic and localization of membrane lipids and proteins to their functional surface domains in polarized epithelial cells. Six highly interrelated projects served by 4 core units will address and compare the problems of molecular targeting and localization in a variety of polarized epithelial cells [MDCK (kidney tubule epithelium), Caco-2 and HT-29 (intestinal epithelium) and WIF12-1 (hepatocyte)] in vitro. These projects address: 1) The lateral organization of membrane proteins and the function of this organization in the sorting and targeting of newly synthesized proteins. 2) The amino acid sequences involved in determining the distribution of an apical (dipeptidylpeptidase-IV) and a basolateral (Na,K-ATPase) protein and of a protein (LEP-100) cycling between lysosomes and the plasma membrane via endosomes. The intracellular transport of these proteins in differential epithelial cells will also be compared. (3) Molecule and vesicle traffic in different epithelial cell types, and the perturbation of this traffic resulting from changes in lipid metabolism or in microtubule architecture. This project will include work on a newly-derived hepatocyte cell line WIF12-1. 4) The isolation and characterization of cis- and trans- Golgi complex membranes as a function of cell type and extent of polarity. 5) The distribution and transport of lipids. Special emphasis will be placed on the movement of fluorescent sphingolipid analogs along secretory pathways and the effects which alterations in cellular sphingolipids and cholesterol may have on lipid sorting and transport. 6) The organization of microtubules, the routes of biosynthetic and endocytic vesicle transport and the mechanoenzymes required for this transport. These six projects will be supported by cores for cell culture, electron microscopy and other imaging, fluorescence measurements of molecular behavior, and administration. The structure, central support and resources proposed here will result in a highly collaborative and interactive approach to the problems of the establishment and maintenance of polarity of epithelial cells.