Plasma membrane and lysosomal localization of CB1 cannabinoid receptor are dependent on lipid rafts and regulated by anandamide in human breast cancer cells |
| |
Authors: | Sarnataro Daniela Grimaldi Claudia Pisanti Simona Gazzerro Patrizia Laezza Chiara Zurzolo Chiara Bifulco Maurizio |
| |
Affiliation: | Dip.di Scienze Farmaceutiche, Università degli Studi di Salerno, Italy. |
| |
Abstract: | In this report we show, by confocal analysis of indirect immunofluorescence, that the type-1 cannabinoid receptor (CB1R), which belongs to the family of G-protein-coupled receptors, is expressed on the plasma membrane in human breast cancer MDA-MB-231 cells. However, a substantial proportion of the receptor is present in lysosomes. We found that CB1R is associated with cholesterol- and sphyngolipid-enriched membrane domains (rafts). Cholesterol depletion by methyl-beta-cyclodextrin (MCD) treatment strongly reduces the flotation of the protein on the raft-fractions (DRM) of sucrose density gradients suggesting that CB1 raft-association is cholesterol dependent. Interestingly binding of the agonist, anandamide (AEA) also impairs DRM-association of the receptor suggesting that the membrane distribution of the receptor is dependent on rafts and is possibly regulated by the agonist binding. Indeed MCD completely blocked the clustering of CB1R at the plasma membrane. On the contrary the lysosomal localization of CB1R was impaired by this treatment only after AEA binding. |
| |
Keywords: | AEA, anandamide Cav1, caveolin 1 DRMs, detergent-resistant microdomains MCD, methyl-β-cyclodextrin GPCRs, G-protein-coupled receptors TNE/TX-100, Tris Na EDTA/Triton X-100 buffer PBS, phosphate buffer saline |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|