Direct observation of the nanoscale dynamics of membrane lipids in a living cell
Direct observation of the nanoscale dynamics of membrane lipids in a living cell
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DOI：
10.1038/nature07596
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发表时间：
2009-02-26
期刊：
影响因子：
64.8
通讯作者：
Hell, Stefan W.
中科院分区：
文献类型：
--
作者：
Eggeling, Christian;Ringemann, Christian;Hell, Stefan W.
胆固醇介导的脂质相互作用被认为在许多膜相关过程中具有功能性作用，例如信号传导事件（1-5）。虽然有几个实验表明它们的存在，但由于缺乏活细胞中合适的检测技术，脂质纳米结构域（“筏”）仍然存在争议（4，6 -9）。这一争议反映在它们的假定尺寸为5-200 nm，跨越了蛋白质复合物的范围和光学显微镜的分辨率极限之间的范围。在这里，我们证明了受激发射耗尽（STED）远场荧光纳米显微镜（10）检测活细胞质膜中纳米尺寸区域中单个扩散（脂质）分子的能力。将探测区域调整到类似于衍射屏障以下70倍的斑点大小，揭示了与磷酸甘油脂不同，鞘脂和糖基磷脂酰肌醇锚定蛋白质被短暂地（类似于10-20 ms）捕获在胆固醇介导的分子复合物中，所述分子复合物驻留在
Cholesterol-mediated lipid interactions are thought to have a functional role in many membrane-associated processes such as signalling events(1-5). Although several experiments indicate their existence, lipid nanodomains ('rafts') remain controversial owing to the lack of suitable detection techniques in living cells(4,6-9). The controversy is reflected in their putative size of 5-200 nm, spanning the range between the extent of a protein complex and the resolution limit of optical microscopy. Here we demonstrate the ability of stimulated emission depletion (STED) far-field fluorescence nanoscopy(10) to detect single diffusing (lipid) molecules in nanosized areas in the plasma membrane of living cells. Tuning of the probed area to spot sizes similar to 70-fold below the diffraction barrier reveals that unlike phosphoglycerolipids, sphingolipids and glycosylphosphatidylinositol-anchored proteins are transiently (similar to 10-20 ms) trapped in cholesterol-mediated molecular complexes dwelling within