Phospholipase A₂ promotes raft budding and fission from giant liposomes

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• 作者：Staneva ; Galya ; Angelova ; Miglena I. ; Koumanov ; Kamen
• 关键词：GUV ; Rafts ; PLA₂ ; Budding ; Vesiculation ; Fission ; GUV ; giant unilamellar vesicle ; PLA₂ ; phospholipase A₂ ; PC ; egg yolk l-α ; -phosphtidylcholine ; SM ; egg yolk sphingomyelin ; Chol ; cholesterol ; PC^* ; fluorescent
• 刊名：Chemistry and Physics of Lipids
• 出版年：2004
• 出版时间：April, 2004
• 年：2004
• 卷：129
• 期：1
• 页码：53-62
• 全文大小：389 K

文摘

Cellular processes involving membrane vesiculation are related to cellular transport and membrane components trafficking. Endocytosis, formation of caveolae and caveosomes, as well as Golgi membranes traffic have been linked to the existence and dynamics of particular types of lipid/protein membrane domains, enriched in sphingolipids and cholesterol, called rafts [Nature 387 (1997) 569; Trends Cell Biol. 12 (2002) 296; Biochemistry 27 (1988) 6197]. In addition, the participation of phospholipases in the vesiculation of Golgi and other membranes has been already established [Traffic 1 (2000) 504] essentially in their role in the production of second messenger molecules. In this work we illustrate with raft-containing giant lipid vesicles a mechanism for raft-vesicle expulsion from the membrane due to the activity of a single enzyme-phospholipase A₂ (PLA₂). This leads to the hypothesis that the PLA₂, apart from its role in second messenger generation, might play a direct and general role in the vesiculation processes underlying the intermembrane transport of rafts through purely physicochemical mechanisms. These mechanisms would be: enzyme adsorption leading to membrane curvature generation (budding), and enzyme activity modulation of the line tension at the raft boundaries, which induces vesicle fission.