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Etapes membranaires de la transduction du signal par les récepteurs couplés aux protéines G : organisation dynamique du récepteur mu aux opioïdes humain à la surface de neuroblastomes.

Abstract : We address the question of the existence of a specific membrane organization which could favor the interactions between the G protein coupled receptor (GPCR), the G protein and the effector. Here we examine the lateral diffusion of the human mu opioid receptor (hMOR) in regard to its activation by ligands and to membrane environment modifications. The T7-EGFP-hMOR stably expressed in SH-SY5Y is found to be fully functional. Its mobility analysis was achieved using two complementary biophysical approaches which are vrFRAP (variable radii fluorescence recovery after photobleaching) and SPT (single particle tracking). At 22°C these analyses reveal a double compartimentation of the receptors in permeable domains (about 1 µm radius) and in smaller domains (200 nm radius). Moreover receptors exhibiting a directed diffusion are observed. The temperature was modulated, the actin cytoskeleton was partially destroyed, and the G protein/receptor interaction was impeded to determine the sources of the receptor organisation. It appears that many parameters are playing a part in the complex receptor organisation. Our results show that the interactions of hMOR with G proteins or with the cortical cytoskeleton influence its membrane organisation. Antagonists binding don't modify the receptor organisation in permeable sub-micrometer size domains. On the contrary agonists binding induce a decrease of both the domain size and the diffusion coefficient. Our results highlight the influence of numerous parameters on the hMOR dynamic organisation. They demonstrate the interest of a conjoint use of vrFRAP and SPT approaches to obtain a global vision of a protein plasma membrane organisation.
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https://tel.archives-ouvertes.fr/tel-00192796
Contributor : Aude Sauliere <>
Submitted on : Thursday, November 29, 2007 - 2:06:25 PM
Last modification on : Thursday, October 15, 2020 - 9:35:25 AM
Long-term archiving on: : Friday, November 25, 2016 - 6:07:15 PM

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  • HAL Id : tel-00192796, version 1

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Aude Sauliere. Etapes membranaires de la transduction du signal par les récepteurs couplés aux protéines G : organisation dynamique du récepteur mu aux opioïdes humain à la surface de neuroblastomes.. Biochimie [q-bio.BM]. Université Paul Sabatier - Toulouse III, 2007. Français. ⟨tel-00192796⟩

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