LIPID & PROTEIN TRAFFIC & DYNAMICS IN EPITHELIAL CELLS

该计划项目旨在了解和定义一些路径， 涉及分拣、交通和本地化的机制和信号 膜脂和蛋白质对其功能表面域的影响 极化的上皮细胞。6个高度相关的项目，由4个 核心单位将解决和比较分子靶向和 多种极化上皮细胞的定位[MDCK(肾脏 小管上皮)、Caco-2和HT-29(肠上皮)和WIF12-1 (肝细胞)]体外培养。这些项目涉及：1)横向 膜蛋白的组织和该组织的功能 新合成蛋白质的分类和靶向。2)氨基酸 参与决定根尖的分布的序列 (二肽基肽酶-IV)和碱侧(Na，K-ATPase)蛋白，以及 蛋白质(LEP-100)在溶酶体和质膜之间通过 内噬菌体。这些蛋白质在细胞内的不同转运 还将对上皮细胞进行比较。(3)分子和囊泡交通 在不同的上皮细胞类型中，以及这种交通的扰动 由脂类代谢或微管结构的改变引起。 该项目将包括一种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和鉴定 复合膜是细胞类型和极性程度的函数。5) 脂类的分布和运输。我们将特别强调 荧光神经鞘糖脂类似物的分泌运动 细胞鞘磷脂的变化及其对细胞的影响 胆固醇可能会对脂质的分类和运输产生影响。6)组织 微管，生物合成和胞内囊泡运输的途径 以及运输所需的机械酶。 这六个项目将由细胞培养、电子 分子的显微镜和其他成像、荧光测量 行为和管理。结构、中心支持和资源 在这里提出的建议将带来高度协作和互动 关于极性建立和维持问题的探讨 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.