Molecular Dissection of the Organization and the Dynamics of Intracellular Lipid Domains

组织的分子解剖和细胞内脂质结构域的动力学

基本信息

批准号：
12672143
负责人：
KOBAYASHI Toshihide
金额：
$ 2.24万
依托单位：
RIKEN
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

项目摘要

I. Involvement of mitochondrial cardiolipin domains in apoptosis.Cytochrome c is a proapoptotic factor that binds preferentially to cardiolipin (CL), a mitochondrial lipid, but not to cardiolipin hydroperoxide (Cl-OOH). Our studies using overexpression of mitochondrial phospholipid hydroperoxide glutathione peroxidase (PHGPx) suggests that the generation of CL-OOH in mitochondria might be a primary event that triggers the release of cytochrome c.II. Characterization of lysobisphosphatidic acid domain in late endosomes.Late endosomes accumulates internal membranes within the lumen of the organelle. These intemal membranes are enriched in the specific lipid, Iysobisphosphatidic acid (LBPA). Using LBPA-specific monoclonal antibody and fluorescence correlation spectroscopy, we have determined that LBPA domain is exclusively localized in the lumen of late endosomes.III. Caveolae and glycosylphosphatidylinositol domain.Most mammalian cells have in their membrane at least two types of lipid m … More icrodomains, non-invaginated lipid rafts and caveolae. Glycosylphosphatidylinositol (GPI)-anchored proteins constitute a class of proteins that are enriched in rafts but not caveolae at steady state. By using GPI-deficient cells and the cells overexpressing caveolin-1, we showed there is an inverse correlation between the expression of GPI-anchored proteins and caveolin-1.IV. Sphingomyelin-specific proteinLysenin is a novel 4lkDa sphingomyelin-binding protein obtained from coelomic fluid of the earthworrn Eisenia foetida. We have developed recombinant lysenin and examined the distribution of sphingomyelin under electron microscope. Sphingomyelin was accumulated in caveolae in endothelial cells. Sphingomyelin was also distributed in endosomes and the trans-Golgi network but excluded from the Golgi cistemae. We also examined sphingomyelin in Niemann-Pick type A (NPA) fibroblpsts, which accumulate sphingomyelin intracellularly Sphingomyelin is accumuiated in late endosomes lysosomes in NPA. Interestingly, other lipid raft components such as ganglioside GM1, and cholesterol were aiso accumulated in the same organelle. Our results suggest that re-distribution of lipid raft occurs in NPA. Less

I. 线粒体心磷脂结构域参与细胞凋亡。细胞色素 c 是一种促凋亡因子，优先与心磷脂 (CL)（一种线粒体脂质）结合，但不与心磷脂氢过氧化物 (Cl-OOH) 结合。我们的研究使用线粒体磷脂氢过氧化物谷胱甘肽过氧化物酶的过表达。 (PHGPx) 表明线粒体中 CL-OOH 的产生可能是触发细胞色素释放的主要事件c.II. 晚期内涵体中溶血二磷脂酸结构域的表征。晚期内涵体在细胞器腔内积累内膜，这些内膜富含特定脂质溶血二磷脂酸 (LBPA)。通过光谱学，我们确定LBPA结构域仅位于晚期内涵体的管腔中。小凹和糖基磷脂酰肌醇结构域。大多数哺乳动物细胞的膜上至少有两种类型的脂质微结构域：非内陷脂筏和糖基磷脂酰肌醇 (GPI) 锚定蛋白构成一类富含脂筏但不富集的蛋白质。通过使用 GPI 缺陷的细胞和过度表达的细胞。 Caveolin-1，我们发现 GPI 锚定蛋白和 Caveolin-1 的表达之间存在负相关。IV。Lysenin 是一种从土爱胜蚓的体腔液中获得的新型 4lkDa 鞘磷脂结合蛋白。开发了重组溶素并在电子显微镜下检查了鞘磷脂的分布。内皮细胞中的鞘磷脂也分布在内体和跨高尔基体网络中，但排除在高尔基池之外。在 NPA 中，暗示其他筏脂质成分，例如神经节苷脂 GM1 和胆固醇也积聚在同一细胞器中，我们的结果表明 NPA 中脂筏的重新分布较少。