Cell cycle dependent changes in membrane stored curvature elastic energy: evidence from lipidomic studies
Cell cycle dependent changes in membrane stored curvature elastic energy: evidence from lipidomic studies
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DOI：
10.1039/c2fd20078c
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发表时间：
2013-01-01
影响因子：
3.4
通讯作者：
Dymond, Marcus K.
中科院分区：
文献类型：
--
作者：
Hague, Charlotte V.;Postle, Anthony D.;Dymond, Marcus K.
最成熟的磷脂动态平衡理论之一是内在曲率假说，广义地说，该假说假设细胞调节其脂质成分，以保持膜储存的曲率弹性能量不变。这一假设的含义是，脂类组成由一个比率控制函数决定，该比率控制函数由分子中II型脂类浓度的加权和和分母中0型脂类浓度的加权和组成。在以前的工作中，我们使用数据驱动的方法，基于来自异步细胞培养的脂体组数据，确定一个标准，允许不同的脂类被分配到0型或II型脂类的集合，从而构建一个比率控制函数，作为体内脂类对总膜存储曲率弹性能的贡献的替代。在这里，我们应用曲率弹性能量代理来分析来自同步HeLa细胞的脂类成分数据，因为它们遍历了细胞周期。我们的分析表明，HeLa细胞在细胞周期中改变了其膜存储的弹性能量。在S期，0型脂质最丰富，而在G2期，II型脂最丰富。我们的膜储存弹性能的变化与HeLa细胞分裂前后膜曲率相关的过程有关，这为个体脂质和蛋白质对膜自由能的贡献之间的相互作用提供了一些见解。
One of the most developed theories of phospholipid homeostasis is the intrinsic curvature hypothesis, which, in broad terms, postulates that cells regulate their lipid composition so as to keep constant the membrane stored curvature elastic energy. The implication of this hypothesis is that lipid composition is determined by a ratio control function consisting of the weighted sum of concentrations of type II lipids in the numerator and the weighted sum of concentrations of Type 0 lipids in the denominator. In previous work we used a data-driven approach, based on lipidomic data from asynchronous cell cultures, to determine a criterion that allows the different lipid species to be assigned to the set of type 0 or of type II lipids, and hence construct a ratio control function that serves as a proxy for the lipid contribution to total membrane stored curvature elastic energy in vivo. Here we apply the curvature elastic energy proxy to the analysis of lipid composition data from synchronous HeLa cells as they traverse the cell cycle. Our analysis suggests HeLa cells modify their membrane stored elastic energy through the cell cycle. In S-phase type 0 lipids are the most abundant, whilst in G2 type II lipids are most abundant. Changes in our proxy for membrane stored elastic energy correlate with membrane curvature dependent processes in the HeLa cell around division, providing some insights into the interplay between the individual lipid and protein contributions to membrane free energy.