Functional GATA-3 binding sites within murine CD8 alpha upstream regulatory sequences.
Genes encoding the accessory molecules CD8 and CD4 are activated early in thymocyte development, generating CD4+8+ double positive intermediates, which give rise to two functionally distinct mature T cell subsets that express either CD4 or CD8. The mechanisms that govern the activation or suppression of the CD8 gene are likely to be central to the T cell development program. To identify the key regulatory factors, we have initiated an analysis of the transcriptional regulation of the murine CD8 alpha gene. We have identified three CD8+ cell-specific DNAase I hypersensitive sites (HSS) located upstream of the murine CD8 alpha gene. In vitro mobility shift analysis of the -4.0-kb HSS region has revealed multiple binding sites for the T cell-restricted transcription factor GATA-3. In vitro translated murine GATA-3 binds specifically to both CD8 GATA sites, and coexpression of this factor in transient transfection assays transactivates a reporter construct containing these sequences. These results provide the first evidence for the role of a T cell-restricted factor in the regulation of either CD8 or CD4 genes.
Landry
D B
DB
Rosenstiel Basic Sciences Center, Brandeis University, Waltham, Massachusetts 02254.
Engel
J D
JD
Sen
R
R
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016827:CD8 Antigens / Q000235:genetics*; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004742:Enhancer Elements, Genetic; D050990:GATA3 Transcription Factor; D005786:Gene Expression Regulation; D066298:In Vitro Techniques; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D016827:CD8 Antigens; D004268:DNA-Binding Proteins; D050990:GATA3 Transcription Factor; C494748:Gata3 protein, mouse; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors