Raft-based interactions of gangliosides with a GPI-anchored receptor
Raft-based interactions of gangliosides with a GPI-anchored receptor
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DOI：
10.1038/nchembio.2059
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发表时间：
2016-06-01
影响因子：
14.8
通讯作者：
Kiso, Makoto
中科院分区：
文献类型：
--
作者：
Komura, Naoko;Suzuki, Kenichi G. N.;Kiso, Makoto
神经节苷脂是糖链上含有一个或多个唾液酸的鞘糖脂，参与细胞膜的多种重要生理和病理过程。然而，它们的确切功能知之甚少，主要是因为缺乏合适的荧光神经节苷脂类似物。在这里，我们开发了系统地合成类似物的方法，这些类似物在分配成筏相关的膜结构域或制剂方面表现得像它们的天然对应物。活细胞质膜中的单荧光分子成像揭示了荧光神经节苷脂类似物与荧光标记的糖基磷脂酰肌醇（GPI）锚定蛋白（人CD 59）的明确但短暂的共定位和共扩散，CD 59单体的寿命为12 ms，静止细胞中CD 59的瞬时同源二聚体筏为40 ms，而粘附的CD 59簇筏为48 ms，以胆固醇和GPI锚定依赖的方式。神经节苷脂分子在静止细胞中总是移动的。这些结果表明，神经节苷脂连续和动态交换之间的筏域和散装域，表明筏域是动态实体。
Gangliosides, glycosphingolipids containing one or more sialic acid(s) in the glyco-chain, are involved in various important physiological and pathological processes in the plasma membrane. However, their exact functions are poorly understood, primarily because of the scarcity of suitable fluorescent ganglioside analogs. Here, we developed methods for systematically synthesizing analogs that behave like their native counterparts in regard to partitioning into raft-related membrane domains or preparations. Single-fluorescent-molecule imaging in the live-cell plasma membrane revealed the clear but transient colocalization and codiffusion of fluorescent ganglioside analogs with a fluorescently labeled glycosylphosphatidylinisotol (GPI)-anchored protein, human CD59, with lifetimes of 12 ms for CD59 monomers, 40 ms for CD59's transient homodimer rafts in quiescent cells, and 48 ms for engaged-CD59-cluster rafts, in cholesterol-and GPI-anchoring-dependent manners. The ganglioside molecules were always mobile in quiescent cells. These results show that gangliosides continually and dynamically exchange between raft domains and the bulk domain, indicating that raft domains are dynamic entities.