Cutting edge: Identification of an alternative GATA-3 promoter directing tissue-specific gene expression in mouse and human.

The GATA family of transcription factors regulates development of multiple tissues. Several GATA factors have two promoters directing distinct tissue-specific expression. Although GATA-3 acts in both neuronal and thymocyte development, no alternative promoter usage has been reported. We examined various cell types and tissues for potential alternative GATA-3 transcripts and identified an alternative transcript directed by a promoter located 10 kb upstream of the recognized promoter. Sequences within this promoter and alternative first exon are highly conserved between mouse and human genomes. This new promoter is expressed selectively in the brain but is essentially undetectable in the thymus. In contrast, the recognized promoter is selectively expressed in the thymus but not in the brain. We also observed a gradual increase in expression from this new promoter during Th2 development. These results indicate that similar to other GATA factors, the GATA-3 gene can be controlled by two promoters that may direct lineage- and tissue-specific expression.