Actin filaments attachment at the plasma membrane in live cells cause the formation of ordered lipid domains
Actin filaments attachment at the plasma membrane in live cells cause the formation of ordered lipid domains
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DOI：
10.1016/j.bbamem.2012.12.004
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发表时间：
2013-03-01
影响因子：
3.4
通讯作者：
Parmryd, Ingela
中科院分区：
文献类型：
--
作者：
Dinic, Jelena;Ashrafzadeh, Parham;Parmryd, Ingela
有序质膜纳米结构域（称为脂筏）和肌动蛋白丝之间的关系是本研究的重点。在37℃的活细胞中，使用laurdan和di-4-ANEPPDHQ报告脂质堆积情况，遵循质膜顺序。破坏肌动蛋白聚合减少了有序结构域的比例，这有力地证明未受刺激的细胞具有基础水平的有序结构域。稳定肌动蛋白丝具有相反的效果，增加了有序结构域的比例。降低4-磷酸肌苷的质膜水平降低了肌动蛋白丝的附着点数量，降低了有序结构域的比例。质膜分子的聚集，包括脂筏和非脂筏标记，导致有序结构域的形成。有序结构域的增加与质膜下肌动蛋白丝的增加有关。在与肌动蛋白丝分离的活细胞膜泡中，有序结构域的比例很低，GM1不能被修补形成有序结构域。我们得出结论，当肌动蛋白丝附着在质膜上时，形成有序结构域。这淡化了脂质相互作用作为体内有序膜结构域形成背后的主要驱动力，而更加突出了膜-细胞内丝的相互作用。(C) 2012 Elsevier B.V.版权所有
The relationship between ordered plasma membrane nanodomains, known as lipid rafts, and actin filaments is the focus of this study. Plasma membrane order was followed in live cells at 37 degrees C using laurdan and di-4-ANEPPDHQ to report on lipid packing. Disrupting actin polymerisation decreased the fraction of ordered domains, which strongly argue that unstimulated cells have a basal level of ordered domains. Stabilising actin filaments had the opposite effect and increased the proportion of ordered domains. Decreasing the plasma membrane level of 4-phosphate-inositides lowers the number of attachment points for actin filaments and reduced the proportion of ordered domains. Aggregation of plasma membrane molecules, both lipid raft and non-lipid raft markers, lead to the formation of ordered domains. The increase in ordered domains was correlated with an increase in actin filaments just beneath the plasma membrane. In live cell plasma membrane blebs, which are detached from the underlying actin filaments, the fraction of ordered domains was low and GM1 could not be patched to form ordered domains. We conclude that ordered domains form when actin filaments attach to the plasma membrane. This downplays lipid-lipid interactions as the main driving force behind the formation of ordered membrane domains in vivo, giving greater prominence to membrane-intracellular filament interactions. (C) 2012 Elsevier B.V. All rights reserved.