The cAMP responsive element and CREB partially mediate the response of the tyrosine hydroxylase gene to phorbol ester.
Tyrosine hydroxylase (TH) gene promoter activity is increased in PC12 cells that are treated with the phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA). Mutagenesis of either the cAMP responsive element (CRE) or the activator protein-1 element (AP1) within the TH gene proximal promoter leads to a dramatic inhibition of the TPA response. The TH CRE and TH AP1 sites are also independently responsive to TPA in minimal promoter constructs. TPA treatment results in phosphorylation of cAMP responsive element binding protein (CREB) and activation of cAMP-dependent protein kinase (PKA) in PC12 cells; hence, we tested whether CREB and/or PKA are essential for the TPA response. In CREB-deficient cells, the response of the full TH gene proximal promoter or the independent response of the TH CRE by itself to TPA is inhibited. The TPA-inducibility of TH mRNA is also blocked in CREB-deficient cells. Expression of the PKA inhibitor protein, PKI, also inhibits the independent response of the TH CRE to TPA. Our results support the hypothesis that TPA stimulates the TH gene promoter via signaling pathways that activate either the TH AP1 or TH CRE sites. Both signaling pathways are dependent on CREB and the TH CRE-mediated pathway is dependent on PKA.
Piech-Dumas
K M
KM
Department of Pharmacology and Physiology, and the Neuroscience Program, University of Rochester Medical Center, Rochester, New York, USA.
Best
J A
JA
Chen
Y
Y
Nagamoto-Combs
K
K
Osterhout
C A
CA
Tank
A W
AW
D000818:Animals; D001665:Binding Sites; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives* / Q000494:pharmacology; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D007700:Kinetics; D016716:PC12 Cells; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013873:Thionucleotides / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*
D017362:Cyclic AMP Response Element-Binding Protein; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D013873:Thionucleotides; D018808:Transcription Factor AP-1; D005576:Colforsin; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000242:Cyclic AMP; D014446:Tyrosine 3-Monooxygenase; D015500:Chloramphenicol O-Acetyltransferase; D017868:Cyclic AMP-Dependent Protein Kinases; D013755:Tetradecanoylphorbol Acetate