CLONING, MAPPING AND EXPRESSION OF PEBP2-ALPHA-C, A 3RD GENE ENCODINGTHE MAMMALIAN RUNT DOMAIN

PEBP2/CBF is a heterodimeric transcription factor composed of alpha an d beta subunits. Previously, we reported two distinct mouse genes, PEB P2 alpha A and PEBP2 alpha B, which encode the a subunit. PEBP2 alpha B is the homologue of human AML1, encoding the acute myeloid leukemia 1 protein. AML1 and human PEBP2/CBF beta were detected independently a t the breakpoints of two characteristic chromosome translocations obse rved frequently in two subtypes of acute myeloid leukemia. The PEBP2 a lpha proteins contain a 128-amino-acid (aa) region highly homologous t o the Drosophila melanogaster segmentation gene runt. The evolutionari ly conserved region, named the Runt domain, harbors DNA-binding and he terodimerizing activities, In this study, we identified the third Runt -domain-encoding gene, PEBP2 alpha C, which maps to 1p36.11-p36.13 in the human chromosome and encodes a 415-aa protein. PEBP2 alpha C forms a heterodimer with PEBP2 beta, binds to the PEBP2 site and transactiv ates transcription, similar to PEBP2 alpha A and PEBP2 alpha B.