Transbilayer distribution of phosphatidylcholine and phosphatidylethanolamine in the vacuolar membrane of Acer pseudoplatanus cells.
The distribution of phosphatidylethanolamine (PE) and phosphatidylcholine (PC) among the outer and inner monolayers of the vacuolar membrane of Acer pseudoplatanus was investigated using isolated vacuoles, chemical labelling agents (trinitrobenzene-sulfonate and fluorescamine), phospholipase A2 from bee venom, phospholipase C and phospholipase D. Treatments were performed with intact or sonicated vacuoles. Analysis of the transbilayer distribution of PC and PE in the vacuolar membrane of Acer was limited by phospholipid fractions which were inaccessible to the probes. Lipid-protein interactions and modification of the surface charge and surface pressure in the membrane layers during treatments may obviously exert a strong influence on labelling or hydrolysis of membrane phospholipids. However, simultaneous treatments carried out with phospholipase A2 and phospholipase C show that PE is approximately 20% more abundant in the outer monolayer than in the inner monolayer and PC is equally distributed between both leaflets of tonoplast. Compared to the phospholipids asymmetrical distribution observed in plasma membrane of erythrocyte, the vacuolar membrane of Acer is not characterized by a marked asymmetrical distribution of its major phospholipids.
Tavernier
E
E
Laboratoire de Biochimie et Biologie Moléculaire, UFR Sciences et Techniques, Besançon, France.
Pugin
A
A
D002478:Cells, Cultured; D005450:Fluorescamine / Q000737:chemistry; D006868:Hydrolysis; D008051:Lipid Bilayers / Q000737:chemistry*; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D010713:Phosphatidylcholines / Q000737:chemistry* / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000737:chemistry* / Q000378:metabolism; D010739:Phospholipase D / Q000737:chemistry / Q000378:metabolism; D010741:Phospholipases A / Q000737:chemistry / Q000378:metabolism; D054467:Phospholipases A2; D014197:Trees / Q000737:chemistry* / Q000166:cytology; D014302:Trinitrobenzenesulfonic Acid / Q000737:chemistry; D010738:Type C Phospholipases / Q000737:chemistry / Q000378:metabolism; D014617:Vacuoles / Q000737:chemistry* / Q000648:ultrastructure
D008051:Lipid Bilayers; D008563:Membrane Lipids; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D005450:Fluorescamine; D014302:Trinitrobenzenesulfonic Acid; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases; D010739:Phospholipase D