Sphingolipids involvement in plant endomembrane differentiation: the BY2 case
Sphingolipids involvement in plant endomembrane differentiation: the BY2 case
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DOI：
10.1111/j.1365-313x.2011.04481.x
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发表时间：
2011-03-01
期刊：
影响因子：
7.2
通讯作者：
Satiat-Jeunemaitre, Beatrice
中科院分区：
文献类型：
--
作者：
Aubert, Anne;Marion, Jessica;Satiat-Jeunemaitre, Beatrice
鞘脂在真核生物的分泌途径中起重要作用。它们在植物细胞功能组织中的重要性以前没有被详细研究过。鞘脂合成抑制剂伏马菌素B1（fumonisin B1，FB1）是一种神经酰胺合成酶特异性抑制剂，本文研究了FB1对BY2细胞生长、细胞极性、细胞形态、细胞周期和超微结构的影响。我们使用的细胞系表达不同的GFP标记的标志物的植物细胞室，以及高尔基体标记融合的光转换蛋白Kaede。光镜和电镜结合流式细胞术，用于分析分泌途径的室的形态动力学和架构。结果表明，FB1处理对细胞生长和细胞形状有严重影响，并诱导细胞分裂过程延迟。细胞的变化伴随着内质网（ER）衍生的管状聚集体（FB1诱导的隔间）的形成，以及从ER到高尔基体的货物运输的抑制。生长素转运蛋白PIN 1的极性定位也发生了变化，但内吞过程几乎没有受到影响。电子显微镜研究证实，分子FB1的目标是不同的布雷菲德菌素A（BFA）的目标。我们建议，神经酰胺生物合成的抑制作用的报告反映了鞘脂在细胞生长和建立细胞极性在高等植物细胞的重要性，特别是通过其贡献的ER的功能组织或其分化成不同的车厢。
Sphingolipids play an essential role in the functioning of the secretory pathway in eukaryotic organisms. Their importance in the functional organization of plant cells has not been studied in any detail before. The sphingolipid synthesis inhibitor fumonisin B1 (FB1), a mycotoxin acting as a specific inhibitor of ceramide synthase, was tested for its effects on cell growth, cell polarity, cell shape, cell cycle and on the ultrastructure of BY2 cells. We used cell lines expressing different GFP-tagged markers for plant cell compartments, as well as a Golgi marker fused to the photoconvertible protein Kaede. Light and electron microscopy, combined with flow cytometry, were applied to analyse the morphodynamics and architecture of compartments of the secretory pathway. The results indicate that FB1 treatment had severe effects on cell growth and cell shape, and induced a delay in cell division processes. The cell changes were accompanied by the formation of the endoplasmic reticulum (ER)-derived tubular aggregates (FB1-induced compartments), together with an inhibition of cargo transport from the ER to the Golgi apparatus. A change in polar localization of the auxin transporter PIN1 was also observed, but endocytic processes were little affected. Electron microscopy studies confirmed that molecular FB1 targets were distinct from brefeldin A (BFA) targets. We propose that the reported effects of inhibition of ceramide biosynthesis reflect the importance of sphingolipids during cell growth and establishment of cell polarity in higher plant cells, notably through their contribution to the functional organization of the ER or its differentiation into distinct compartments.