A single-stranded DNA binding site in the human A1 adenosine receptor gene promoter.
Human A1 adenosine receptor gene expression is controlled by two independent promoters. The upstream promoter, promoter A, is subject to tissue specific regulation because not all cells express the mRNA associated with this promoter. One potential regulatory sequence located downstream of the TATA box is an AGG element appearing in a tandem repeat. In a previous study, transient transfection assays showed that mutations made in those AGG elements substantially reduced promoter activity. In the current study, DNase I footprinting indicated nuclear protein binding to this sequence between the TATA box and transcriptional start site. Electrophoretic mobility shift assay confirmed further the presence of an AGG element binding protein (AGBP) in human brain nuclear protein extracts. This binding protein has much higher affinity for single-stranded than for double-stranded DNA, and the binding is sequence specific. A series of assays also showed that AGBP is not related to the nuclear factor SP1 and the binding does not require metal cofactors. Therefore, AGBP is likely to be a specific single-stranded DNA binding protein that is required for the full expression of A1 adenosine receptor gene and particularly abundant in brain tissue.
Ren
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Department of Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA.
Stiles
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D001483:Base Sequence; D001665:Binding Sites; D001921:Brain / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D018983:DNA Footprinting; D015342:DNA Probes; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000378:metabolism; D004533:Egtazic Acid / Q000494:pharmacology; D004586:Electrophoresis; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000502:physiology*; D018047:Receptors, Purinergic P1 / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D016329:Sp1 Transcription Factor / Q000378:metabolism; D013379:Substrate Specificity; D016385:TATA Box / Q000502:physiology; D015032:Zinc / Q000494:pharmacology
D015342:DNA Probes; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D018047:Receptors, Purinergic P1; D016329:Sp1 Transcription Factor; D004533:Egtazic Acid; D004247:DNA; D003850:Deoxyribonuclease I; D015032:Zinc