Kappa-opioid receptor signals through Src and focal adhesion kinase to stimulate c-Jun N-terminal kinases in transfected COS-7 cells and human monocytic THP-1 cells.
Opioid peptides exert diverse physiological functions through their cognate receptors. One subtype of the opioid receptors, kappa-opioid receptor, is endogenously expressed in human monocytic THP-1 cells. Stimulation of the THP-1 cells with a kappa-opioid receptor-selective agonist exerted a Gi-dependent activation of c-Jun N-terminal kinase (JNK). To further investigate the signaling mechanism by which the kappa-opioid receptor regulates JNK activity, heterologous expression assays in COS-7 cells were utilized. Overexpression of Galphat in COS-7 cells clearly suppressed kappa-opioid receptor-stimulated JNK activity, indicating that the pathway is primarily regulated by Gbetagamma. In both THP-1 and transfected COS-7 cells, pretreatment of the selective Src family kinase inhibitor pyrazolopyrimidine PP1 abolished the JNK activation, whereas the epidermal growth factor receptor inhibitor AG1478 [N-(3-chlorophenyl)-6,7-dimethoxy-4-quinazolinanine] failed to do that. Furthermore, the JNK activation in response to kappa-opioid receptor was suppressed by an autophosphorylation-resistant mutant of focal adhesion kinase (FAK). Consistently, activated kappa-opioid receptor induced Src stimulation and FAK autophosphorylation and promoted the formation of Src-FAK complex. The participation of small GTPases as well as a guanine nucleotide exchange factor was also implicated because dominant-negative mutants of Rac, Cdc42, and Son-of-sevenless (Sos) attenuated the agonist-induced activation of JNK. These studies demonstrate that the activation of JNK by kappa-opioid receptors is routed via Gbetagamma, Src, FAK, Sos, Rac, and Cdc42.
Kam
Angel Y F
AY
Department of Biochemistry, the Molecular Neuroscience Center, and the Biotechnology Research Institute, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Chan
Anthony S L
AS
Wong
Yung H
YH
D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D004268:DNA-Binding Proteins; D004789:Enzyme Activation; D066246:ErbB Receptors / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D020558:GTP Phosphohydrolases / Q000378:metabolism; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009000:Monocytes / Q000201:enzymology / Q000378:metabolism*; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D017473:Receptors, Opioid, kappa / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D014162:Transfection; D019061:src-Family Kinases / Q000378:metabolism*
D004268:DNA-Binding Proteins; D017473:Receptors, Opioid, kappa; C480633:SLC2A4RG protein, human; D014157:Transcription Factors; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; D019061:src-Family Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D020558:GTP Phosphohydrolases; D019206:GTP-Binding Protein alpha Subunits, Gi-Go