We have previously identified the region which is required for the ETS2 transcription. We used the minimal ETS2 promoter region to identify factors that are involved in ETS2 transcriptional regulation. Gel mobility shift and methylation interference assays reveal that at least five distinct protein complexes interact with the region surrounding the major transcription initiation site. None of the interactions involve known proteins, as indicated by the inability to complete the effect with target sequences by known transcription factors (Sp1, AP1, AP2, AP3, NF1). Two of the DNA protein complexes involve the GC element with dyad symmetry which we previously identified to exist in other genes. Three other complexes have been localized to the region immediately 3' of the major transcription initiation points; one of these complexes is lymphoid specific and the others are ubiquitous (detected in every nuclear extract tested). Point mutagenesis of the DNA binding sites and subsequent determination of the promoter activity reveals that the integrity of the sites is required for proper ETS2 MRNA transcription. The identification of the DNA binding sites on the ETS2 promoter will allow the isolation and characterization of the genes involved in the ETS2 transcription unit.
