부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.bbamem.2008.03.017 Byline: Aurore Andre, Gerald Gaibelet, Laurent Le Guyader, Michele Welby, Andre Lopez, Chantal Lebrun Keywords: GPCR; hDOR; Lateral organization; Raft; Hydrophobic mismatch; Cholesterol Abstract: Lipid rafts depicted as densely packed and thicker membrane microdomains, based on the dynamic clustering of cholesterol and sphingolipids, may help as platforms involved in a wide variety of cellular processes. The reasons why proteins segregate into rafts are yet to be clarified. The human delta opioid receptor (hDOR) reconstituted in a model system has been characterised after ligand binding by an elongation of its transmembrane part, inducing rearrangement of its lipid microenvironment [Alves, Salamon, Hruby, and Tollin (2005) Biochemistry 44, 9168-9178]. We used hDOR to understand better the correlation between its function and its membrane microdomain localisation. A fusion protein of hDOR with the Green Fluorescent Protein (DOR[cor]) allows precise receptor membrane quantification. Here we report that (i) a fraction of the total receptor pool requires cholesterol for binding activity, (ii) G-proteins stabilize a high affinity state conformation which does not seem modulated by cholesterol. In relation to its distribution, and (iii) a fraction of DOR[cor] is constitutively associated with detergent-resistant membranes (DRM) characterised by an enrichment in lipids and proteins raft markers. (iv) An increase in the quantity of DOR[cor] was observed upon agonist addition. (v) This DRM relocation is prevented by uncoupling the receptor-G-protein interaction. Author Affiliation: IPBS, MR5089 CNRS/UPS, 205 Route de Narbonne, 31077 Toulouse Cedex 4, France Article History: Received 8 January 2008; Revised 10 March 2008; Accepted 24 March 2008