title: Modulation of μ-opioid receptor signaling by RGS19 in SH-SY5Y cells.
abstract: Regulator of G-protein signaling protein 19 (RGS19), also known as Gα-interacting protein (GAIP), acts as a GTPase accelerating protein for Gαz as well as Gαi/o subunits. Interactions with GAIP-interacting protein N-terminus and GAIP-interacting protein C-terminus (GIPC) link RGS19 to a variety of intracellular proteins. Here we show that RGS19 is abundantly expressed in human neuroblastoma SH-SY5Y cells that also express µ- and δ- opioid receptors (MORs and DORs, respectively) and nociceptin receptors (NOPRs). Lentiviral delivery of short hairpin RNA specifically targeted to RGS19 reduced RGS19 protein levels by 69%, with a similar reduction in GIPC. In RGS19-depleted cells, there was an increase in the ability of MOR (morphine) but not of DOR [(4-[(R)-[(2S,5R)-4-allyl-2,5-dimethylpiperazin-1-yl](3-methoxyphenyl)methyl]-N,N-diethylbenzamide (SNC80)] or NOPR (nociceptin) agonists to inhibit forskolin-stimulated adenylyl cyclase and increase mitogen-activated protein kinase (MAPK) activity. Overnight treatment with either MOR [D-Ala, N-Me-Phe, Gly-ol(5)-enkephalin (DAMGO) or morphine] or DOR (D-Pen(5)-enkephalin or SNC80) agonists increased RGS19 and GIPC protein levels in a time- and concentration-dependent manner. The MOR-induced increase in RGS19 protein was prevented by pretreatment with pertussis toxin or the opioid antagonist naloxone. Protein kinase C (PKC) activation alone increased the level of RGS19 and inhibitors of PKC 5,6,7,13-tetrahydro-13-methyl-5-oxo-12H-indolo[2,3-a]pyrrolo[3,4-c]carbazole-12-propanenitrile and mitogen-activated protein kinase kinase 1 2-(2-amino-3-methoxyphenyl)-4H-chromen-4-one, but not protein kinase A (H89), completely blocked DAMGO-induced RGS19 protein accumulation. The findings show that RGS19 and GIPC are jointly regulated, that RGS19 is a GTPase accelerating protein for MOR with selectivity over DOR and NOPR, and that chronic MOR or DOR agonist treatment increases RGS19 levels by a PKC and the MAPK pathway-dependent mechanism.
authors.affiliation: Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, USA.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.forename: John R
authors.initials: JR
authors.lastname: Traynor
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D005576:Colforsin / Q000494:pharmacology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)- / Q000494:pharmacology; D057809:HEK293 Cells; D006801:Humans; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D009020:Morphine / Q000494:pharmacology; D018847:Opioid Peptides / Q000494:pharmacology; D016716:PC12 Cells; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D020710:RGS Proteins / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D011957:Receptors, Opioid / Q000235:genetics / Q000378:metabolism; D017465:Receptors, Opioid, delta / Q000819:agonists / Q000235:genetics / Q000378:metabolism; D017450:Receptors, Opioid, mu / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D000262:Adenylyl Cyclases; D001549:Benzamides; D005576:Colforsin; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020928:Mitogen-Activated Protein Kinases; D009020:Morphine; D018847:Opioid Peptides; D010879:Piperazines; D011493:Protein Kinase C; D020710:RGS Proteins; D011957:Receptors, Opioid; D017465:Receptors, Opioid, delta; D017450:Receptors, Opioid, mu; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C492009:GIPC1 protein, human; C097187:regulator of G-protein signalling 19; C088464:4-(alpha-(4-allyl-2,5-dimethyl-1-piperazinyl)-3-methoxybenzyl)-N,N-diethylbenzamide