title: AP-2beta represses D(1A) dopamine receptor gene transcription in neuro2a cells.
abstract: Expression of the D(1A) dopamine receptor in brain is restricted to specific neuronal populations. To investigate the mechanism of this selective expression, we localized a silencer upstream of the human D(1A) gene and identified its binding transcription factor in the D(1A)-negative neural cell line Neuro2a. Using deletion CAT analysis, we narrowed this silencer to the region between nucleotides -561 and -532 relative to the CAP site. This 30-bp region, designated D1AS1, contains a sequence homologous to the AP-2 binding site and binds to a factor that also interacts with the AP-2 consensus sequence. In gel supershift assays, this factor is recognized by anti-AP-2beta antibody. Co-transfection of Neuro2a cells with an AP-2beta expression vector repressed the basal CAT activity of D(1A) promoter-reporter plasmids in a D1AS1-dependent manner. RT-PCR analysis indicated that, among AP-2 family members, Neuro2a cells express only AP-2beta. Furthermore, co-transfection of these cells with decoy oligonucleotides corresponding to the D1AS1 sequence de-repressed the D(1A) gene promoter. Unlike in Neuro2a cells, AP-2beta could not repress the D(1A) promoter in the D(1A)-positive neural cell line, NS20Y. In addition, the expression of AP-2beta in different brain regions does not inversely correlate with that of D(1A) dopamine receptor. These observations taken together indicate that AP-2beta is a repressive transcription factor that acts on the D1AS1 silencer of the D(1A) dopamine receptor gene via some cell-specific mechanism(s) in Neuro2a.
authors.affiliation: Department of Neurology, Graduate School of Medicine, University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Takeuchi
authors.forename: I
authors.initials: I
authors.lastname: Imafuku
authors.forename: M
authors.initials: M
authors.lastname: Waragai
authors.forename: C
authors.initials: C
authors.lastname: Roth
authors.forename: I
authors.initials: I
authors.lastname: Kanazawa
authors.forename: R
authors.initials: R
authors.lastname: Buettner
authors.forename: M M
authors.initials: MM
authors.lastname: Mouradian
authors.forename: H
authors.initials: H
authors.lastname: Okazawa
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005786:Gene Expression Regulation; D006801:Humans; D051379:Mice; D009687:Nuclear Proteins / Q000378:metabolism; D009841:Oligonucleotides / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D017447:Receptors, Dopamine D1 / Q000235:genetics* / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured; D015854:Up-Regulation
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D009841:Oligonucleotides; D017447:Receptors, Dopamine D1; D011993:Recombinant Fusion Proteins; C493677:TFAP2B protein, human; C493669:Tfap2b protein, mouse; D050656:Transcription Factor AP-2; D014157:Transcription Factors; C098593:dopamine D1A receptor; D015500:Chloramphenicol O-Acetyltransferase