Characterization of lipid rafts from Medicago truncatula root plasma membranes: a proteomic study reveals the presence of a raft-associated redox system.
Several studies have provided new insights into the role of sphingolipid/sterol-rich domains so-called lipid rafts of the plasma membrane (PM) from mammalian cells, and more recently from leaves, cell cultures, and seedlings of higher plants. Here we show that lipid raft domains, defined as Triton X-100-insoluble membranes, can also be prepared from Medicago truncatula root PMs. These domains have been extensively characterized by ultrastructural studies as well as by analysis of their content in lipids and proteins. M. truncatula lipid domains are shown to be enriched in sphingolipids and Delta(7)-sterols, with spinasterol as the major compound, but also in steryl glycosides and acyl-steryl glycosides. A large number of proteins (i.e. 270) have been identified. Among them, receptor kinases and proteins related to signaling, cellular trafficking, and cell wall functioning were well represented whereas those involved in transport and metabolism were poorly represented. Evidence is also given for the presence of a complete PM redox system in the lipid rafts.
Lefebvre
Benoit
B
Laboratoire des Interactions Plantes Micro-organismes, Unité Mixte de Recherche, Centre National de la Recherche Scientifique-Institut National de la Recherche Agronomique 2594/441, 31326 Castanet-Tolosan cedex, France.
Furt
Fabienne
F
Hartmann
Marie-Andrée
MA
Michaelson
Louise V
LV
Carde
Jean-Pierre
JP
Sargueil-Boiron
Françoise
F
Rossignol
Michel
M
Napier
Johnathan A
JA
Cullimore
Julie
J
Bessoule
Jean-Jacques
JJ
Mongrand
Sébastien
S
D002458:Cell Fractionation; D046913:Medicago truncatula / Q000378:metabolism* / Q000648:ultrastructure; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D021962:Membrane Microdomains / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D010084:Oxidation-Reduction; D010940:Plant Proteins / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism / Q000648:ultrastructure; D040901:Proteomics; D012995:Solubility; D013265:Stigmasterol / Q000031:analogs & derivatives / Q000378:metabolism
D008563:Membrane Lipids; D010940:Plant Proteins; C031312:spinasterol; D013265:Stigmasterol