INTRACELLULAR TRANSLOCATION AND METABOLISM OF LIPIDS

脂质分子的分子机制 合成、分选并运输到各种细胞质中， 将研究动物细胞内的隔室。 一系列 荧光脂质类似物将用于关联 活细胞中脂质代谢物的细胞内分布， 如通过荧光显微镜所测定的， 生化分析 在可能的情况下，将进行类似的研究。 使用放射性标记的脂质及其前体进行。 的 目的是：（一）研究囊泡和非囊泡的作用， 脂质转运至血浆和从血浆转运的囊泡机制 （二）研究代谢、分选和转运 鞘脂通过ER/高尔基复合体;（iii）研究 代谢和运输的一系列荧光和 正常和突变人皮肤中的放射性神经节苷脂 （四）检查一些合成的网站 亚细胞膜鞘脂及其前体 从大鼠肝脏分离的组分;和（v）研究相互作用 脂质体与半完整的细胞内膜 （“穿孔”）细胞。 荧光脂质的研究 活细胞将通过共振能量转移 显微镜，最近在这个实验室开发的。 和毗邻 最近获得的微光数字成像荧光 显微镜 一些研究将依赖于一个数字的合成 具有荧光的脂质类似物（及其立体异构体）。 放射性或光亲和标记。 这些将用于 将各种运输机制彼此区分开来， 有助于识别参与脂质合成的细胞蛋白质， 分类和运输。 本申请中提出的研究 是理解膜组装和调节的基础， 膜脂组成的细胞，是根本的 开发膜或细胞表面的合理处理方法- 相关疾病状态。

The molecular mechanisms by which lipid molecules are synthesized, sorted, and transported to various cytoplasmic compartments within animal cells will be studied. A series of fluorescent lipid analogs will be used to correlate the intracellular distribution of lipid metabolites in living cells, as determined by fluorescence microscopy, with traditional lipid biochemical analyses. Where possible, similar studies will be performed using radiolabeled lipids and their precursors. The goals are to: (i) examine the role of vesicular and non- vesicular mechanisms of lipid transport to and from the plasma membrane; (ii) study the metabolism, sorting, and transport of sphingolipids through the ER/Golgi complex; (iii) study the metabolism and transport of a series of fluorescent and radioactive gangliosides in normal and mutant human skin fibroblasts; (iv) examine the sites of synthesis of some sphingolipids and their precursors in subcellular membrane fractions isolated from rat liver; and (v) study the interactions of liposomes with the intracellular membranes of semi-intact ("perforated") cells. Studies of the fluorescent lipids in living cells will be facilitated by resonance energy transfer microscopy, as recently developed in this laboratory. and by a recently acquired low-light-level digital imaging fluorescence microscope. Some studies will rely on the synthesis of a number of lipid analogs (and their stereoisomers) bearing fluorescent. radioactive, or photoaffinity labels. These will be used to distinguish various transport mechanisms from one another and to help identify the cellular proteins involved in lipid synthesis, sorting, and transport. The studies proposed in this application are basic to understanding membrane assembly and regulation of membrane lipid composition in cells and are fundamental to the development of rational treatments of membrane or cell surface- related disease states.