title: AP1 proteins mediate the cAMP response of the dopamine beta-hydroxylase gene.
abstract: Neurotransmitter biosynthesis is regulated by environmental stimuli, which transmit intracellular signals via second messengers and protein kinase pathways. For the catecholamine biosynthetic enzymes, dopamine beta-hydroxylase and tyrosine hydroxylase, regulation of gene expression by cyclic AMP, diacyl glycerol, and Ca2+ leads to increased neurotransmitter biosynthesis. In this report, we demonstrate that the cAMP-mediated regulation of transcription from the dopamine beta-hydroxylase promoter is mediated by the AP1 proteins c-Fos, c-Jun, and JunD. Following treatment of cultured cells with cAMP, protein complexes bound to the dopamine beta-hydroxylase AP1/cAMP response element element change from consisting of c-Jun and JunD to include c-Fos, c-Jun, and JunD. The homeodomain protein Arix is also a component of this DNA-protein complex, binding to the adjacent homeodomain recognition sites. Transfection of a dominant negative JunD expression plasmid inhibits cAMP-mediated expression of the dopamine beta-hydroxylase promoter construct in PC12 and CATH.a cells. In addition to the role of c-Fos in regulating dopamine beta-hydroxylase gene expression in response to cAMP, a second pathway, involving Rap1/B-Raf is involved. These experiments illustrate an unusual divergence of cAMP-dependent protein kinase signaling through multiple pathways that then reconverge on a single element in the dopamine beta-hydroxylase promoter to elicit activation of gene expression.
authors.affiliation: Department of Biochemistry and Molecular Biology, Oregon Health Sciences University, L224, Portland, Oregon 97201, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Swanson
authors.forename: E
authors.initials: E
authors.lastname: Zellmer
authors.forename: E J
authors.initials: EJ
authors.lastname: Lewis
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D002999:Clone Cells; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000378:metabolism* / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D004299:Dopamine beta-Hydroxylase / Q000096:biosynthesis / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D019204:GTP-Binding Proteins / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016716:PC12 Cells; D011401:Promoter Regions, Genetic; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis; D016385:TATA Box; D013873:Thionucleotides / Q000494:pharmacology*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D020668:rap GTP-Binding Proteins
chemical_list: D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D011994:Recombinant Proteins; D013873:Thionucleotides; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000242:Cyclic AMP; D004299:Dopamine beta-Hydroxylase; D017868:Cyclic AMP-Dependent Protein Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019204:GTP-Binding Proteins; D020668:rap GTP-Binding Proteins