LATERAL ORGANIZATION OF EPITHELIAL CELL SURFACES

上皮细胞，占体内所有细胞的50%[和 占所有人类癌症的90%]具有定义功能 创建和维护身体的生理隔间。 它们在功能和形态上被极化，以便 执行此功能。脂类锚定蛋白，GPI=蛋白和 糖鞘糖脂主要集中在大多数牙根尖表面。 极化的上皮细胞。我们建议使用生物物理 研究分类的形成和组织的技巧 高尔基体和质膜中GPI-蛋白的单位 比较MDCK细胞中的分选单元，其中GPI-蛋白是 直接输送到根尖表面，在WIF-B肝细胞中， 其中顶端蛋白通过间接途径到达顶端 浮出水面。我们还将比较不同组织的横向组织 MDCK细胞和脂质体中的GPI-蛋白。以下问题 将讨论：1)GPI-蛋白和GSL是如何浓缩的 与高尔基体中的其他蛋白质分离？2)什么是细胞& GPI-蛋白聚集性和极性的蛋白质特异性 在完全培养的细胞中生长，并在细胞中消除它们的极性 被剥夺了低密度脂蛋白？我们解决这些问题的技术包括 荧光光漂白和恢复，荧光损失 光漂白、翻转和成像荧光共振能量 转移，烦躁。

Epithelial cells, which comprise 50% of all cells in the body [and account for 90% of all human cancers] have as a defining function the creation and maintenance of physiological compartments of the body. They are functionally and morphologically polarized in order to perform this function. Lipid-anchored proteins, GPI=proteins and glycosphingolipids are concentrated at the apical surfaces of most polarized epithelial cells. We propose to use biophysical techniques to study the formation, and organization of the sorting units for GPI-proteins in the Golgi and plasma membranes and to compare the sorting units in MDCK cells, in which GPI-proteins are delivered directly to the apical surface, and in WIF-B hepatocytes, in which apical proteins take an indirect route to the apical surface. We will also compare the lateral organization of different GPI-proteins in MDCK cells and in liposomes. The following questions will be address: 1) How are GPI-proteins and GSL concentrated and segregated from other proteins in the Golgi? 2) What are the cell & protein specificities of the clustering and polarity of GPI-proteins in cells grown in complete medium and abolish their polarity in cells deprived of LDL? Our techniques to address these questions include fluorescence photo bleaching and recovery, FPR, fluorescence loss in photo bleaching, FLIP, and imaging fluorescence resonance energy transfer, FRET.