title: Ras/MEK pathway is required for NGF-induced expression of tyrosine hydroxylase gene.
abstract: Neurotrophins are essential for the development and survival of catecholaminergic neurons. However, the critical pathway for expression of the tyrosine hydroxylase (TH) gene induced by neurotrophin is still unclear. Here we found that Ras/MEK pathway is required for NGF-induced expression of the TH gene in PC12D cells. Induction of TH mRNA by NGF was abolished by pretreatment of the cells with U0126, an inhibitor for MEK1/2, but not with inhibitors for p38 MAPK, PI3K, and PKA. U0126 inhibited TH promoter activity at the same concentration as it acted on ERK1/2 phosphorylation. A dominant-negative form of Ras suppressed the NGF-induced activation of the TH reporter gene, and transient transfection of cells with wild-type Ras and an active form of MEK1 increased the TH promoter activity. The reporter assay also demonstrated that the Ras/MEK pathway acted on both the AP-1-binding motif and the cAMP-responsive element in the TH promoter.
authors.affiliation: Department of Life Science, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Yokohama, Japan. tsuzuki@bio.titech.ac.jp
authors.forename: Takahiro
authors.initials: T
authors.lastname: Suzuki
authors.forename: Hiroki
authors.initials: H
authors.lastname: Kurahashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ichinose
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D008156:Luciferases / Q000378:metabolism; D020930:MAP Kinase Kinase Kinases / Q000378:metabolism*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009154:Mutation; D020932:Nerve Growth Factor / Q000378:metabolism*; D009414:Nerve Growth Factors / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D016716:PC12 Cells; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D048051:p38 Mitogen-Activated Protein Kinases; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D002070:Butadienes; D004791:Enzyme Inhibitors; D009414:Nerve Growth Factors; D009570:Nitriles; D012333:RNA, Messenger; C113580:U 0126; D020932:Nerve Growth Factor; D000242:Cyclic AMP; D008156:Luciferases; D014446:Tyrosine 3-Monooxygenase; D019869:Phosphatidylinositol 3-Kinases; D017868:Cyclic AMP-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D020930:MAP Kinase Kinase Kinases; D018631:ras Proteins