Insights into the Role of Specific Lipids in the Formation and Delivery of Lipid Microdomains to the Plasma Membrane of Plant Cells

• Published in: Plant physiology (Bethesda) Vol. 143; no. 1; pp. 461 - 472
• Main Authors: Laloi, Maryse, Perret, Anne-Marie, Chatre, Laurent, Melser, Su, Cantrel, Catherine, Vaultier, Marie-Noëlle, Zachowski, Alain, Bathany, Katell, Schmitter, Jean-Marie, Vallet, Myriam, Lessire, René, Hartmann, Marie-Andrèe, Moreau, Patrick
• Format: Journal Article
• Language: English
• Published: Rockville, MD American Society of Plant Biologists 01.01.2007; American Society of Plant Physiologists; Oxford University Press ; American Society of Plant Biologists
• Subjects: Animal cells; Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - metabolism; Biochemical Processes and Macromolecular Structures; Biological and medical sciences; Biological Transport - physiology; Cell lines; Cell Membrane - drug effects; Cell Membrane - metabolism; Cell membranes; Cell physiology; Cells, Cultured; Cellular Biology; Fatty acids; Fens; Fundamental and applied biological sciences. Psychology; Leeks; Life Sciences; Lipids; Membrane Lipids - metabolism; Membrane Lipids - physiology; Membrane Microdomains - metabolism; Microsomes - metabolism; Morpholines - pharmacology; Mutation; Onions - drug effects; Onions - metabolism; Phospholipids - metabolism; Plant cells; Plant physiology and development; Plasma membrane and permeation; Seedlings; Seedlings - drug effects; Seedlings - metabolism; Steroid Isomerases - antagonists & inhibitors; Sterols; Sterols - metabolism; Subcellular Fractions; Lipids; Plasma membrane
• ISSN: 0032-0889; 1532-2548; 1532-2548
• DOI: 10.1104/pp.106.091496

The existence of sphingolipid- and sterol-enriched microdomains, known as lipid rafts, in the plasma membrane (PM) of eukaryotic cells is well documented. To obtain more insight into the lipid molecular species required for the formation of microdomains in plants, we have isolated detergent (Triton X-100)-resistant membranes (DRMs) from the PM of Arabidopsis (Arabidopsis thaliana) and leek (Allium porrum) seedlings as well as from Arabidopsis cell cultures. Here, we show that all DRM preparations are enriched in sterols, sterylglucosides, and glucosylceramides (GluCer) and depleted in glycerophospholipids. The GluCer of DRMs from leek seedlings contain hydroxypalmitic acid. We investigated the role of sterols in DRM formation along the secretory pathway in leek seedlings. We present evidence for the presence of DRMs in both the PM and the Golgi apparatus but not in the endoplasmic reticulum. In leek seedlings treated with fenpropimorph, a sterol biosynthesis inhibitor, the usual Δ⁵-sterols are replaced by 9δ,19-cyclopropylsterols. In these plants, sterols and hydroxypalmitic acid-containing GluCer do not reach the PM, and most DRMs are recovered from the Golgi apparatus, indicating that Δ⁵-sterols and GluCer play a crucial role in lipid microdomain formation and delivery to the PM. In addition, DRM formation in Arabidopsis cells is shown to depend on the unsaturation degree of fatty acyl chains as evidenced by the dramatic decrease in the amount of DRMs prepared from the Arabidopsis mutants, fad2 and Fad3+, affected in their fatty acid desaturases.