title: Identification of new intrinsic proteins in Arabidopsis plasma membrane proteome.
abstract: Identification and characterization of anion channel genes in plants represent a goal for a better understanding of their central role in cell signaling, osmoregulation, nutrition, and metabolism. Though channel activities have been well characterized in plasma membrane by electrophysiology, the corresponding molecular entities are little documented. Indeed, the hydrophobic protein equipment of plant plasma membrane still remains largely unknown, though several proteomic approaches have been reported. To identify new putative transport systems, we developed a new proteomic strategy based on mass spectrometry analyses of a plasma membrane fraction enriched in hydrophobic proteins. We produced from Arabidopsis cell suspensions a highly purified plasma membrane fraction and characterized it in detail by immunological and enzymatic tests. Using complementary methods for the extraction of hydrophobic proteins and mass spectrometry analyses on mono-dimensional gels, about 100 proteins have been identified, 95% of which had never been found in previous proteomic studies. The inventory of the plasma membrane proteome generated by this approach contains numerous plasma membrane integral proteins, one-third displaying at least four transmembrane segments. The plasma membrane localization was confirmed for several proteins, therefore validating such proteomic strategy. An in silico analysis shows a correlation between the putative functions of the identified proteins and the expected roles for plasma membrane in transport, signaling, cellular traffic, and metabolism. This analysis also reveals 10 proteins that display structural properties compatible with transport functions and will constitute interesting targets for further functional studies.
authors.affiliation: Institut des Sciences du Végétal, Centre National de la Recherche Scientifique-Unité Propre de Recherche, 91198 Gif sur Yvette Cedex, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Marmagne
authors.forename: Marie-Aude
authors.initials: MA
authors.lastname: Rouet
authors.forename: Myriam
authors.initials: M
authors.lastname: Ferro
authors.forename: Norbert
authors.initials: N
authors.lastname: Rolland
authors.forename: Carine
authors.initials: C
authors.lastname: Alcon
authors.forename: Jacques
authors.initials: J
authors.lastname: Joyard
authors.forename: Jérome
authors.initials: J
authors.lastname: Garin
authors.forename: Hélène
authors.initials: H
authors.lastname: Barbier-Brygoo
authors.forename: Geneviève
authors.initials: G
authors.lastname: Ephritikhine
mesh_terms: D017360:Arabidopsis / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D002458:Cell Fractionation; D002462:Cell Membrane / Q000378:metabolism*; D030562:Databases, Protein; D004591:Electrophoresis, Polyacrylamide Gel; D013058:Mass Spectrometry; D020543:Proteome
chemical_list: D029681:Arabidopsis Proteins; D020543:Proteome