PEBP2 PEA2 REPRESENTS A FAMILY OF TRANSCRIPTION FACTORS HOMOLOGOUS TOTHE PRODUCTS OF THE DROSOPHILA RUNT GENE AND THE HUMAN AML1 GENE/

cDNAs representing the alpha subunit of polyomavirus enhancer binding protein 2 (PEBP2; also called PEA2) were isolated. The products of the cDNAs are highly homologous to that of Drosophila segmentation gene r unt (run) for an N-proximal 128-amino acid region showing 66% identity . The run homology region encompasses the domain capable of binding to a specific nucleotide sequence motif and of dimerizing with the compa nion beta subunit. The human AML1 gene related to t(8;21) acute myeloi d leukemia also has a run homology region. Together with the beta subu nit, which increases the affinity of the alpha subunit to DNA without binding to DNA by itself, PEBP2 represents a newly discovered family o f transcription factor. The major species of PEBP2alpha mRNA was expre ssed in T-cell lines but not in B-cell lines tested. Evidence indicate d that PEBP2 functions as a transcriptional activator and is involved in regulation of T-cell-specific gene expression.