T-cell expression of the human GATA-3 gene is regulated by a non-lineage-specific silencer.
The GATA-3 transcription factor is required for development of the T-cell lineage and Th2 cytokine gene expression in CD4 T-cells. We have mapped the DNase-I-hypersensitive (HS) regions of the human GATA-3 gene in T-cells and non-T-cells and studied their transcriptional activities. HS I-III, located 5' from the transcriptional initiation site, were found in hematopoietic and non-hematopoietic cells, whereas HS IV-VII, located 3' from the transcriptional start site, were exclusively observed in T-cells. Among these hypersensitive sites, two transcriptional control elements were found, one in the first intron of the GATA-3 gene and the other between 8.3 and 5.9 kilobases 5' from the GATA-3 transcriptional initiation site. The first intron acted as a strong transcriptional activator in a position-dependent manner and with no cell-type specificity. The upstream regulatory element could confer T-cell specificity to the GATA-3 promoter activity, and analysis of this region revealed a 707-base pair silencer that drastically inhibited GATA-3 promoter activity in non-T-cells. Two CAGGTG E-boxes, located at the 5'- and 3'-ends of the silencer, were necessary for this silencer activity. The 3'-CAGGTG E-box could bind USF proteins, the ubiquitous repressor ZEB, or the basic helix-loop-helix proteins E2A and HEB, and we showed that a competition between ZEB and E2A/HEB proteins is involved in the silencer activity.
Grégoire
J M
JM
INSERM U.474, Hôpital Henri Mondor, 94010 Créteil, France.
Roméo
P H
PH
D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism*; D002460:Cell Line; D019070:Cell Lineage / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D050990:GATA3 Transcription Factor; D005786:Gene Expression Regulation; D018257:Helix-Loop-Helix Motifs; D006801:Humans; D008969:Molecular Sequence Data; D015534:Trans-Activators / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D050990:GATA3 Transcription Factor; C494749:GATA3 protein, human; D015534:Trans-Activators