title: Signalling pathway leading to an activation of mitogen-activated protein kinase by stimulating M3 muscarinic receptor.
abstract: The signalling pathway leading to an activation of mitogen-activated protein (MAP) kinase subtypes Erk-1 and -2 upon stimulation of muscarinic receptor with carbachol in human neuroblastoma SK-N-BE2(C) cells was investigated. Carbachol activated Erk-1/-2 by stimulating M3 muscarinic receptor, as determined by specific antagonists for individual muscarinic receptors. The activation of Erk-1/-2 by carbachol was blocked by the inhibition or down-regulation of protein kinase C (PKC). Among the multiple PKC isoforms expressed in SK-N-BE2(C) cells, only PKCepsilon was activated by the treatment of carbachol, and selective down-regulation of PKCepsilon was sufficient to block Erk-1/-2 activation. Carbachol treatment induced activation of the serine/threonine protein kinase Raf, and an inhibition of Raf blocked Erk-1/-2 activation. Ectopic expression of inhibitory small GTPase Ras, RasN17, blocked the carbachol-induced Raf activation without affecting the activation of PKCepsilon, while the inhibition of PKC blocked the Raf activation. Thus, these results suggest that carbachol-induced activation of PKCepsilon mediates Erk-1/-2 activation by a sequential activation of Ras, Raf and MAP kinase kinase.
authors.affiliation: Department of Biology, Kyungpook National University, Taegu 702-701, Korea.
authors.forename: J Y
authors.initials: JY
authors.lastname: Kim
authors.forename: M S
authors.initials: MS
authors.lastname: Yang
authors.forename: C D
authors.initials: CD
authors.lastname: Oh
authors.forename: K T
authors.initials: KT
authors.lastname: Kim
authors.forename: M J
authors.initials: MJ
authors.lastname: Ha
authors.forename: S S
authors.initials: SS
authors.lastname: Kang
authors.forename: J S
authors.initials: JS
authors.lastname: Chun
mesh_terms: D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002217:Carbachol / Q000494:pharmacology; D004789:Enzyme Activation; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D011493:Protein Kinase C / Q000378:metabolism*; D051744:Protein Kinase C-epsilon; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic / Q000378:metabolism*; D015398:Signal Transduction; D014407:Tumor Cells, Cultured
chemical_list: D007527:Isoenzymes; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic; D002217:Carbachol; D019908:Proto-Oncogene Proteins c-raf; C497255:PRKCE protein, human; D011493:Protein Kinase C; D051744:Protein Kinase C-epsilon; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)