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.线粒体心脂蛋白结构域在凋亡中的参与。CytoChromeC是一种促凋亡因子，优先结合了Cardiolipin（CL），即线粒体脂质，但与心霉素氢氧化氢（CL-OOH）不相同。我们使用线粒体磷脂氢过氧化物谷胱甘肽过氧化物酶（PHGPX）的过表达的研究表明，线粒体中CL-OOH的产生可能是触发细胞色素c.ii的释放的主要事件。内体晚期内体的溶血磷脂酸结构域的表征。内体累积了细胞器管腔内的内膜。这些无膜膜富集在特定的脂质二异糖磷脂酸（LBPA）中。使用LBPA特异性的单克隆抗体和荧光相关光谱，我们确定LBPA结构域仅位于后期内体的腔内中。小窝和糖基磷脂酰肌醇结构域。大多数哺乳动物细胞在其膜中至少具有两种类型的脂质M…更多的红色菌群，非疾病的脂质木筏和小窝。糖基磷脂酰肌醇（GPI）锚定的蛋白质构成一类蛋白质，这些蛋白质富含木筏，但在稳定状态下不富含小窝。通过使用gpi特殊细胞和过表达小窝蛋白-1的细胞，我们表明GPI锚定蛋白的表达与小窝蛋白1.IV之间存在逆相关性。鞘磷脂特异性蛋白赖森蛋白是一种新型的4LKDA鞘磷脂结合蛋白，该蛋白质从fore虫的卵巢液中获得。我们已经开发了重组溶素，并检查了电子显微镜下鞘磷脂的分布。鞘磷脂也分布在内体和反式高尔基网络中，但被排除在高尔基体cistemae中。我们还检查了niemann-pick型A型（NPA）fibroBLPST中的鞘磷脂，这些鞘磷脂积聚在NPA的晚期内体溶酶体中积累细胞内鞘磷脂。有趣的是，其他脂质筏成分（例如神经节苷脂GM1和胆固醇）在同一细胞器中积聚。我们的结果表明，NPA发生脂质筏的重新分布。较少的