PEBP2/PEA2 represents a family of transcription factors homologous to the 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 runt (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 companion beta subunit. The human AML1 gene related to t(8;21) acute myeloid leukemia also had a run homology region. Together with the beta subunit, which increases the affinity of the alpha subunit to DNA without binding to DNA by itself, PEBP2 represents a newly discovered family of transcription factor. The major species of PEBP2 alpha mRNA was expressed in T-cell lines but not in B-cell lines tested. Evidence indicated that PEBP2 functions as a transcriptional activator and is involved in regulation of T-cell-specific gene expression.