The ets family proteins are important transcriptional activators that regulate a variety of genes which control cell proliferation, differentiation and development. The ets proteins bind DNA, in a sequence-specific manner, to purine-rich GGAA core sequences. The function and regulation of the ets family of genes has been investigated and it has been found that the ets-1 proto-oncogene is positively autoregulated. By using synthetic oligonucleotides, it has been shown that the ets-1 protein binds to its own promoter, as well as several other promoter/enhancer regions of cellular and viral genes. In this study, it is shown that the ets-1 protein binds to the erythroid-specific transcription factor, GATA-1 promoter, HIV-1 LTR and MHC class I promoter/enhancer sequences. In a transient cotransfection experiment, it was observed that the ets proteins can transactivate transcription from vectors containing the reporter CAT gene linked to the synthetic ets DNA- binding sequences from either MHC class I or GATA-1 gene promoters and HIV LTR. Interestingly, similar to ets family proteins, many of the gene promoters that contain ets DNA-binding sequences are active in hematopoietic cells. The ability of the ets proteins to interact with these ets motifs will likely depend upon the particular ets family protein that is expressed in that cell or tissue type.
