title: Free-flow electrophoresis for fractionation of Arabidopsis thaliana membranes.
abstract: Highly purified tonoplast and plasma membrane vesicles were isolated from microsomes of Arabidopsis thaliana by preparative free-flow electrophoresis. The most electronegative fractions were identified as tonoplast using nitrate-inhibited Mg2+-ATPase as enzyme marker. The least electronegative fractions were identified as plasma membrane using glucan-synthase II, UDPG: sterol-glucosyl-transferase, and vanadate-inhibited Mg2+-ATPase as enzyme markers. Other membrane markers, latent inosine-5'-diphosphatase (Golgi), NADPH-cytochrome-c reductase (endoplasmic reticulum) and cytochrome-c oxidase (mitochondria) were recovered in the fractions intermediate between tonoplast and plasma membrane. Immunoblot analysis of membrane fractions by antibodies directed against tonoplast and plasma membrane proteins confirmed the nature and the purity of the isolated membranes. The cytoskeletal protein actin, which was also identified by immunoblotting, was found to be specifically attached to the plasma membrane vesicles. The structural and functional integrity of the isolated membranes from Arabidopsis thaliana is discussed in the light of results obtained for the location of receptors and enzymes, or for the determination of ligand binding activity.
authors.affiliation: Signaux et Messages Cellulaires chez les Végétaux, UMR 5546 CNRS, Université Paul Sabatier, Toulouse, France.
authors.forename: N
authors.initials: N
authors.lastname: Bardy
authors.forename: A
authors.initials: A
authors.lastname: Carrasco
authors.forename: J P
authors.initials: JP
authors.lastname: Galaud
authors.forename: R
authors.initials: R
authors.lastname: Pont-Lezica
authors.forename: H
authors.initials: H
authors.lastname: Canut
mesh_terms: D000937:Antigen-Antibody Reactions; D017360:Arabidopsis; D015415:Biomarkers / Q000032:analysis; D002458:Cell Fractionation / Q000379:methods*; D002462:Cell Membrane / Q000737:chemistry / Q000201:enzymology / Q000276:immunology; D002736:Chloroplasts / Q000737:chemistry / Q000276:immunology; D004586:Electrophoresis / Q000379:methods*; D007425:Intracellular Membranes / Q000737:chemistry / Q000201:enzymology; D008565:Membrane Proteins / Q000032:analysis* / Q000276:immunology; D010940:Plant Proteins / Q000032:analysis; D013347:Subcellular Fractions / Q000737:chemistry / Q000201:enzymology
chemical_list: D015415:Biomarkers; D008565:Membrane Proteins; D010940:Plant Proteins