Regulation of mu opioid receptor internalization by the scaffold protein RanBPM.
Mu opioid receptors (MOP) are transducers of the pharmacological effects of many opioid drugs, including analgesia and tolerance/dependence. Previously, we observed increased MOP signaling during postnatal development that was not associated with increased MOP or G protein expression. A yeast two-hybrid screen of a human brain cDNA library using the MOP C-terminus as bait identified RanBPM as a potential MOP-interacting protein. RanBPM has been recognized as a multi-functional scaffold protein that interacts with a variety of signaling receptors/proteins. Co-immunoprecipitation studies in HEK293 cells indicated that RanBPM constitutively associates with MOP. Functionally, RanBPM had no effect on MOP-mediated inhibition of adenylyl cyclase, yet reduced agonist-induced endocytosis of MOP. Mechanistically, RanBPM interfered with beta arrestin2-GFP translocation stimulated by MOP but not alpha(1B)-adrenergic receptor activation, indicating selectivity of action. Our findings suggest that RanBPM is a novel MOP-interacting protein that negatively regulates receptor internalization without altering MOP signaling through adenylyl cyclase.
Department of Pharmacology and Experimental Neuroscience, 985800 Nebraska Medical Center, Omaha, NE 68198-5800, USA.
Jeffery N
JN
Talbot
Donald A
DA
Skifter
Elisabetta
E
Bianchi
Daniel T
DT
Monaghan
Myron L
ML
Toews
L Charles
LC
Murrin
D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis / Q000502:physiology*; D000067956:Adenylyl Cyclase Inhibitors; D000262:Adenylyl Cyclases / Q000502:physiology; D019390:Arrestins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D000242:Cyclic AMP / Q000096:biosynthesis; D003598:Cytoskeletal Proteins / Q000096:biosynthesis / Q000502:physiology*; D004705:Endocytosis; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000502:physiology*; D025941:Protein Interaction Mapping; D021381:Protein Transport; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000378:metabolism*; D020798:Two-Hybrid System Techniques; D000071557:beta-Arrestins
C547716:ADRA1B protein, human; D048868:Adaptor Proteins, Signal Transducing; D000067956:Adenylyl Cyclase Inhibitors; D019390:Arrestins; D003598:Cytoskeletal Proteins; D009687:Nuclear Proteins; C116005:Ran binding protein 9; D018340:Receptors, Adrenergic, alpha-1; D017450:Receptors, Opioid, mu; D000071557:beta-Arrestins; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D049452:Green Fluorescent Proteins; D000242:Cyclic AMP; D000262:Adenylyl Cyclases