Identification of GATA3 binding sites in Jurkat cells.

Determining binding sites of transcription factors is important for understanding the transcriptional control of target genes. Although a transcription factor GATA3 plays a pivotal role in Th2 lymphocyte development, its physiological role is not clearly defined because the target genes remain largely unknown. In this study, we modified chromatin immunoprecipitation (ChIP), and isolated 121 GATA3 binding sites and 83 different annotated target genes. Re-ChIP analysis using anti-GATA3 and anti-RNA polymerase II mAbs and chromosome conformation capture assay demonstrate that GATA3-bound fragments interact with basal transcriptional units of target genes. GATA3 regulation of target genes under the control of binding fragments was confirmed by reporter assay and quantification of target gene mRNA expression in the presence of GATA inhibitor or short interfering RNA against GATA3. These data demonstrate that GATA3 binds to regulatory elements and controls target gene expression through physical interaction with core promoter regions.