Requirement for cAMP/calcium response element but not AP-1 site in fibroblast growth factor-2-elicited activation of tyrosine hydroxylase gene expression in PC12 cells.
Basic fibroblast growth factor (FGF-2) mediates numerous important physiological processes, including differentiation and survival of dopaminergic neurons. FGF-2 was found to trigger elevation of tyrosine hydroxylase (TH) gene expression in PC12 cells that was sustained for 1-8 days. FGF-2 induced chloramphenicol acetyltransferase (CAT) reporter activity under control of the TH promoter, indicating that the induction is transcriptionally mediated. The transcriptional activation of TH by FGF-2 was examined using various deletions and point mutations of the 5' flanking region controlling CAT reporter activity. In contrast to the reported mechanisms of transcriptional regulation of TH expression by NGF and phorbol esters, the AP-1 site at -205/-199 was not required for the activation by FGF-2. A construct containing only 60 nucleotides of the promoter was still inducible by FGF-2. However, a construct with a point mutation in the CRE/CaRE was not responsive to induction by FGF-2. These findings indicate that the CRE/CaRE, but not the AP-1, element is required for induction by FGF-2 and point to differences between NGF and FGF-2 in the regulation of TH gene expression.
Osaka
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Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla 10595, USA.
Sabban
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D000818:Animals; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism*; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D000242:Cyclic AMP / Q000378:metabolism*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D017930:Genes, Reporter; D007700:Kinetics; D009414:Nerve Growth Factors / Q000494:pharmacology; D016716:PC12 Cells; D010703:Phorbol Esters / Q000494:pharmacology; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017384:Sequence Deletion; D013997:Time Factors; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation / Q000187:drug effects; D014162:Transfection; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis* / Q000235:genetics
D017362:Cyclic AMP Response Element-Binding Protein; D009414:Nerve Growth Factors; D010703:Phorbol Esters; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D018808:Transcription Factor AP-1; D016222:Fibroblast Growth Factor 2; D000242:Cyclic AMP; D014446:Tyrosine 3-Monooxygenase; D015500:Chloramphenicol O-Acetyltransferase; D002118:Calcium