There are some indications that biased μ-opioid ligands may diversely affect μ-opioid receptor (MOR) properties. Here, we used confocal fluorescence recovery after photobleaching (FRAP) to study the regulation by different MOR agonists of receptor movement within the plasma membrane of HEK293 cells stably expressing a functional yellow fluorescent protein (YFP)-tagged μ-opioid receptor (MOR-YFP). We found that the lateral mobility of MOR-YFP was increased by (D-Ala2,N-MePhe4,Gly5-ol)-enkephalin (DAMGO) and to a lesser extent also by morphine but decreased by endomorphin-2. Interestingly, cholesterol depletion strongly enhanced the ability of morphine to elevate receptor mobility but significantly reduced or even eliminated the effect of DAMGO and endomorphin-2, respectively. Moreover, the ability of DAMGO and endomorphin-2 to influence MOR-YFP movement was diminished by pertussis toxin treatment. The results obtained by agonist-stimulated [35S]GTPγS binding assays indicated that DAMGO exhibited higher efficacy than morphine and endomorphin-2 did and that the efficacy of DAMGO, contrary to the latter agonists, was enhanced by cholesterol depletion. Overall, our study provides clear evidence that biased MOR agonists diversely affect receptor mobility in plasma membranes as well as MOR/G protein coupling and that the regulatory effect of different ligands depends on the membrane cholesterol content. These findings help to delineate the fundamental properties of MOR regarding their interaction with biased MOR ligands and cognate G proteins.

• Klíčová slova
• Biased agonists *, Cholesterol *, FRAP *, G protein coupling *, μ-Opioid receptor *,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• cholesterol nedostatek   MeSH
• enkefalin, Ala(2)-MePhe(4)-Gly(5)- metabolismus   farmakologie   MeSH
• FRAP MeSH
• guanosin 5'-O-(3-thiotrifosfát) metabolismus   MeSH
• HEK293 buňky MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• ligandy MeSH
• luminescentní proteiny genetika   metabolismus   MeSH
• morfin metabolismus   farmakologie   MeSH
• narkotika - antagonisté farmakologie   MeSH
• oligopeptidy metabolismus   farmakologie   MeSH
• pertusový toxin farmakologie   MeSH
• proteiny vázající GTP - alfa-podjednotky Gi-Go metabolismus   MeSH
• receptory opiátové mu agonisté   genetika   metabolismus   MeSH
• rekombinantní fúzní proteiny metabolismus   MeSH
• transfekce MeSH
• transport proteinů MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Názvy látek
• bakteriální proteiny MeSH
• cholesterol MeSH
• endomorphin 2 MeSH Prohlížeč
• enkefalin, Ala(2)-MePhe(4)-Gly(5)- MeSH
• guanosin 5'-O-(3-thiotrifosfát) MeSH
• ligandy MeSH
• luminescentní proteiny MeSH
• morfin MeSH
• narkotika - antagonisté MeSH
• oligopeptidy MeSH
• pertusový toxin MeSH
• proteiny vázající GTP - alfa-podjednotky Gi-Go MeSH
• receptory opiátové mu MeSH
• rekombinantní fúzní proteiny MeSH
• yellow fluorescent protein, Bacteria MeSH Prohlížeč