Activation of delta-, kappa-, and mu-opioid receptors induces phosphorylation of tuberin in transfected HEK 293 cells and native cells.
A number of G protein-coupled receptors have been shown to stimulate tuberin phosphorylation, which is critical for the regulation of translation and is apparently involved in neurotrophin-promoted survival of serum-deprived cells. Here, in HEK 293 cells transiently expressing the delta-, kappa-, or mu-opioid receptors, Western blotting analysis using a phosphospecific anti-tuberin antibody revealed a dose- and time-dependent increase in tuberin phosphorylation upon stimulation by specific opioid agonists. In NG108-15, PC12, and SH-SY5Y cells that endogenously express delta-, kappa-, and mu-opioid receptors, respectively, specific opioid agonists also stimulated tuberin phosphorylation in a dose- and time-dependent manner. Pretreatment of cells with pertussis toxin or PI3K inhibitor wortmannin blocked the opioid-stimulated tuberin phosphorylation, implicating the possible involvement of the G(i/o) proteins and the phosphatidylinositol-3 kinase/Akt pathway in opioid-induced tuberin phosphorylation. This is the first study that demonstrates the regulatory role of opioid receptors on tuberin.
Wu
Eddy H T
EH
Department of Biochemistry, The Molecular Neuroscience Center, The Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Wong
Yung H
YH
D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer / Q000494:pharmacology; D002460:Cell Line; D002478:Cells, Cultured; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism; D006801:Humans; D037342:Pertussis Toxin / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D017465:Receptors, Opioid, delta / Q000502:physiology*; D017473:Receptors, Opioid, kappa / Q000502:physiology*; D017450:Receptors, Opioid, mu / Q000502:physiology*; D015533:Transcriptional Activation; D014162:Transfection; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins / Q000378:metabolism*
D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; C000624653:TSC2 protein, human; D000077005:Tuberous Sclerosis Complex 2 Protein; D025521:Tumor Suppressor Proteins; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D019900:3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer; D020881:Enkephalin, D-Penicillamine (2,5)-; D037342:Pertussis Toxin; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; D019206:GTP-Binding Protein alpha Subunits, Gi-Go