Plasma and vacuolar membrane sphingolipidomes: composition and insights on the role of main molecular species
Plasma and vacuolar membrane sphingolipidomes: composition and insights on the role of main molecular species
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DOI：
10.1093/plphys/kiab064
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发表时间：
2021-02-11
期刊：
影响因子：
7.4
通讯作者：
Gavilanes-Ruiz, Marina
中科院分区：
文献类型：
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作者：
Carmona-Salazar, Laura;Cahoon, Rebecca E.;Gavilanes-Ruiz, Marina
脂质结构影响膜的生物物理特性，例如厚度、稳定性、渗透性、曲率、流动性、不对称性和交错性，从而有助于膜功能。鞘脂在植物内膜和质膜 (PM) 中含量丰富，包括四类：神经酰胺、羟基神经酰胺、葡萄糖基神经酰胺和糖基肌醇磷酸神经酰胺 (GIPC)。它们构成了一系列化学结构，其在植物膜中的分布尚不清楚。为了描述鞘脂的疏水部分，从拟南芥 (Arabidopsis thaliana) 叶子中分离出微粒体 (MIC)、液泡 (VM)、PM 和耐洗涤剂膜 (DRM) 的 18 种制剂。在这些膜中对鞘脂种类（包括长链碱基和脂肪酸的配对）进行了鉴定和定量。使用单变量和多变量分析比较鞘脂浓度，以评估鞘脂多样性、丰度和跨膜优势。四种鞘脂类在每个膜中以不同的水平存在：VM 富含葡萄糖神经酰胺、羟基神经酰胺和 GIPC；VM 富含葡萄糖神经酰胺、羟基神经酰胺和 GIPC； GIPC 中的 PM，与其在信号识别和传感中的关键作用一致； GIPC 中的 DRM 和 DRM，如其在纳米域形成中的功能所报道的。虽然在 MIC、VM、PM 和 DRM 中总共鉴定出 84 种鞘脂，但只有 34 种选择性分布在四种膜类型中。相反，每个膜包含不同数量的主要物种（VM 中 11 个、PM 中 6 个、DRM 中 17 个）。这项研究表明，MIC、VM、PM 和 DRM 包含相同的鞘脂种类，但每种膜源都包含基于鞘脂种类的比例和单个种类的优势的特定分类。
Lipid structures affect membrane biophysical properties such as thickness, stability, permeability, curvature, fluidity, asymmetry, and interdigitation, contributing to membrane function. Sphingolipids are abundant in plant endomembranes and plasma membranes (PMs) and comprise four classes: ceramides, hydroxyceramides, glucosylceramides, and glycosylinositolphosphoceramides (GIPCs). They constitute an array of chemical structures whose distribution in plant membranes is unknown. With the aim of describing the hydrophobic portion of sphingolipids, 18 preparations from microsomal (MIC), vacuolar (VM), PM, and detergent-resistant membranes (DRM) were isolated from Arabidopsis (Arabidopsis thaliana) leaves. Sphingolipid species, encompassing pairing of long-chain bases and fatty acids, were identified and quantified in these membranes. Sphingolipid concentrations were compared using univariate and multivariate analysis to assess sphingolipid diversity, abundance, and predominance across membranes. The four sphingolipid classes were present at different levels in each membrane: VM was enriched in glucosylceramides, hydroxyceramides, and GIPCs; PM in GIPCs, in agreement with their key role in signal recognition and sensing; and DRM in GIPCs, as reported by their function in nanodomain formation. While a total of 84 sphingolipid species was identified in MIC, VM, PM, and DRM, only 34 were selectively distributed in the four membrane types. Conversely, every membrane contained a different number of predominant species (11 in VM, 6 in PM, and 17 in DRM). This study reveals that MIC, VM, PM, and DRM contain the same set of sphingolipid species but every membrane source contains its own specific assortment based on the proportion of sphingolipid classes and on the predominance of individual species.