Long acyl chain ceramides govern cholesterol and cytoskeleton dependence of membrane outer leaflet dynamics
Long acyl chain ceramides govern cholesterol and cytoskeleton dependence of membrane outer leaflet dynamics
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DOI：
10.1016/j.bbamem.2019.183153
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发表时间：
2020-03-01
影响因子：
3.4
通讯作者：
Wohland, Thorsten
中科院分区：
文献类型：
--
作者：
Gupta, Anjali;Muralidharan, Sneha;Wohland, Thorsten
质膜的时空动态是膜组分之间精细调节的相互作用的结果。然而，维持这种微妙平衡的分子因子的确切身份，即使在细胞膜衍生的模拟物中也丢失了，仍然难以捉摸。在这里，我们使用两种细胞系CHO-K1和RBL-2H3，这两种细胞系在外膜组织、动力学和细胞骨架偶联方面表现出差异，来研究潜在的因素。令我们惊讶的是，在RBL-2H3细胞中丰富但在CHO-K1细胞中不存在的细胞骨架相互作用免疫球蛋白E受体的敲除与脂质限制或细胞骨架偶联无关。随后对两种细胞膜的脂质组学分析揭示了总膜神经酰胺含量（C16至C24）的差异。成像荧光相关光谱分析神经酰胺处理活细胞膜的动力学和组织表明，C24和C16饱和神经酰胺通过促进胆固醇非依赖性结构域的形成和提高叶间偶联来独特地改变膜动力学。
The spatiotemporal dynamics of the plasma membrane is a consequence of fine-tuned interactions between membrane components. However, the precise identity of molecular factors that maintain this delicate balance, which is lost even in cell membrane derived mimics, remains elusive. Here, we use two cell lines, CHO-K1 and RBL-2H3, which show differences in outer membrane organization, dynamics, and cytoskeleton coupling, to investigate the underlying factors. To our surprise, knock-down of the cytoskeleton-interacting Immunoglobulin E receptor, which is abundant in RBL-2H3 but not in CHO-K1 cells, is not responsible for lipid confinement or cytoskeleton coupling. A subsequent lipidomic analysis of the two cell membranes revealed differences in total membrane ceramide content (C16 to C24). Analysis of the dynamics and organization of ceramide treated live cell membranes by imaging fluorescence correlation spectroscopy demonstrates that C24 and C16 saturated ceramides uniquely alter membrane dynamics by promoting the formation of cholesterol-independent domains and by elevating the inter-leaflet coupling.