title: delta-Opioid receptor gene: effect of Sp1 factor on transcriptional regulation in vivo.
abstract: delta-Opioid receptor (DOR) promoter exhibited a cell-type-specific expression pattern. Protein-DNA interactions in this promoter were identified by dimethyl sulfate in vivo footprinting analysis of NG108-15 cells, expressing endogenous DOR. Complete protection of the putative Sp1 cis-element and partial protection of the sequence defined as X-NotI in the basal promoter were observed only in the G0/G1 phase of the cell cycle. No protection was detected in Neuro2A cells that do not express DOR. In vivo formaldehyde cross-linking confirmed Sp1 factor binding to its cis-acting element during the G0/G1 phase. The functional significance of these Sp1 and X-NotI sites was evaluated by transient transfection analysis. Northern blot analysis and nuclear run-off assays revealed maximum DOR mRNA level and transcription rate, respectively, during the G0/G1 phase of NG108-15 cells. In summary, the protein-DNA interactions at the Sp1 and X-NotI sites are necessary for cell cycle-dependent and cell-type-specific up-regulated DOR gene expression.
authors.affiliation: Department of Pharmacology, University of Minnesota Medical School, Minneapolis, Minnesota, USA. smirn001@tc.umn.edu
authors.forename: D
authors.initials: D
authors.lastname: Smirnov
authors.forename: H J
authors.initials: HJ
authors.lastname: Im
authors.forename: H H
authors.initials: HH
authors.lastname: Loh
mesh_terms: D017398:Alternative Splicing; D000818:Animals; D015152:Blotting, Northern; D002453:Cell Cycle / Q000502:physiology; D003432:Cross-Linking Reagents / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D018983:DNA Footprinting; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000378:metabolism; D005557:Formaldehyde / Q000378:metabolism; D005786:Gene Expression Regulation; D006822:Hybrid Cells; D051379:Mice; D011401:Promoter Regions, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017465:Receptors, Opioid, delta / Q000235:genetics*; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D017465:Receptors, Opioid, delta; D016329:Sp1 Transcription Factor; D005557:Formaldehyde; D004247:DNA