Differential Effect of Plant Lipids on Membrane Organization SPECIFICITIES OF PHYTOSPHINGOLIPIDS AND PHYTOSTEROLS
Differential Effect of Plant Lipids on Membrane Organization SPECIFICITIES OF PHYTOSPHINGOLIPIDS AND PHYTOSTEROLS
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DOI：
10.1074/jbc.m114.598805
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发表时间：
2015-02-27
影响因子：
4.8
通讯作者：
Gerbeau-Pissot, Patricia
中科院分区：
文献类型：
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作者：
Grosjean, Kevin;Mongrand, Sebastien;Gerbeau-Pissot, Patricia
植物脂质混合物的高度多样性提出了它们各自参与膜组织定义的问题。对于植物质膜来说尤其如此，质膜富含特定的脂质，如游离和共轭形式的植物甾醇和典型的植物鞘脂质，如糖基肌醇磷酸神经酰胺。这个问题在这里得到了广泛的解决，通过表征膜的有序水平，从使用各种植物脂质混合物制备的囊泡和环境敏感探针标记。荧光光谱实验表明，在主要植物甾醇中，油菜甾醇比β -谷甾醇和豆甾醇表现出更强的模式膜排序能力。通过多光谱共聚焦显微镜对膜组织进行空间分析，结果表明油菜甾醇具有促进有序结构域形成和组织其在膜表面空间分布的强大能力。缀合甾醇形式，单独或与游离甾醇协同作用，表现出惊人的膜有序能力。植物鞘脂，特别是糖基肌醇磷酸神经酰胺，增强了甾醇诱导的有序效应，强调了甾醇依赖有序结构域的形成并增加了其大小。总之，我们的研究结果支持了自由和共轭植物甾醇在有序结构域形成中的不同参与，并表明植物脂的多样性，允许脂类的不同局部组合，可能是膜组织的主要因素，特别是通过鞘脂-甾醇相互作用结构域的形成。
The high diversity of the plant lipid mixture raises the question of their respective involvement in the definition of membrane organization. This is particularly the case for plant plasma membrane, which is enriched in specific lipids, such as free and conjugated forms of phytosterols and typical phytosphingolipids, such as glycosylinositolphosphoceramides. This question was here addressed extensively by characterizing the order level of membrane from vesicles prepared using various plant lipid mixtures and labeled with an environment-sensitive probe. Fluorescence spectroscopy experiments showed that among major phytosterols, campesterol exhibits a stronger ability than beta-sitosterol and stigmasterol to order model membranes. Multispectral confocal microscopy, allowing spatial analysis of membrane organization, demonstrated accordingly the strong ability of campesterol to promote ordered domain formation and to organize their spatial distribution at the membrane surface. Conjugated sterol forms, alone and in synergy with free sterols, exhibit a striking ability to order membrane. Plant sphingolipids, particularly glycosylinositolphosphoceramides, enhanced the sterol-induced ordering effect, emphasizing the formation and increasing the size of sterol-dependent ordered domains. Altogether, our results support a differential involvement of free and conjugated phytosterols in the formation of ordered domains and suggest that the diversity of plant lipids, allowing various local combinations of lipid species, could be a major contributor to membrane organization in particular through the formation of sphingolipid-sterol interacting domains.