Cholesterol-dependent phase separation in cell-derived giant plasma-membrane vesicles
Cholesterol-dependent phase separation in cell-derived giant plasma-membrane vesicles
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DOI：
10.1042/bj20091283
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发表时间：
2009-12-01
影响因子：
4.1
通讯作者：
Janmey, Paul A.
中科院分区：
文献类型：
--
作者：
Levental, Ilya;Byfield, Fitzroy J.;Janmey, Paul A.
细胞衍生的 GPMV（巨型质膜囊泡）能够在生理条件下研究具有适当生物复杂性的系统中的脂质相分离，并且在本研究中用于研究结构域形成和稳定性的胆固醇依赖性。胆固醇水平与液体有序相部分的丰度直接相关，液体有序相部分是未经处理的细胞的囊泡中的主要相。混溶性转变温度取决于胆固醇，并与细胞裂解液中去污剂不溶性膜的存在密切相关。荧光相关光谱揭示了相分离的细胞膜来源的囊泡中的两个不同的扩散群体，其扩散率与模型系统和活细胞中的扩散率很好地对应。本研究的结果将先前对纯化脂质系统的观察扩展到质膜的复杂环境，并深入了解胆固醇对脂质相分离和丰度的影响。
Cell-derived GPMVs (giant plasma-membrane vesicles) enable investigation of lipid phase separation in a system with appropriate biological complexity under physiological conditions, and in the present study were used to investigate the cholesterol-dependence of domain formation and stability. The cholesterol level is directly related to the abundance of the liquid-ordered phase fraction, which is the majority phase in vesicles from untreated cells. Miscibility transition temperature depends on cholesterol and correlates strongly with the presence of detergent-insoluble membrane in cell lysates. Fluorescence correlation spectroscopy reveals two distinct diffusing populations in phase-separated cell membrane-derived vesicles whose diffusivities correspond well to diffusivities in both model systems and live cells. The results of the present study extend previous observations in purified lipid systems to the complex environment of the plasma membrane and provide insight into the effect of cholesterol on lipid phase separation and abundance.