Visualizing differences in ligand-induced beta-arrestin-GFP interactions and trafficking between three recently characterized G protein-coupled receptors.

摘要: beta-Arrestin 1-GFP or beta-arrestin 2-GFP were coexpressed transiently with G protein-coupled receptor kinase 2 within cells stably expressing the orexin-1, apelin melanin-concentrating hormone (MCH), receptors. In response to agonist ligands both orexin-1 and receptors able rapidly translocate from cytoplasm plasma membrane. For MCH this was only observed for 2-GFP. translocated by remained at membrane during prolonged exposure ligand even though became internalized. By contrast, receptor, internalization of punctate vesicles could be over 60 min in continued presence agonist. Co-internalization monitoring binding trafficking TAMRA-(5- 6-carboxytetramethylrhodamine) labelled orexin-A. Subsequent addition an antagonist resulted cessation incorporation into a gradual clearance intracellular vesicles. bulk maintained concentrated foci close to, at, These results demonstrate very distinct features beta-arrestin-GFP interactions three which natural have recently been identified thus previously considered as orphan