THE EVI-1 ZINC-FINGER MYELOID TRANSFORMING PROTEIN BINDS TO GENOMIC FRAGMENTS CONTAINING (GATA)(N) SEQUENCES

The EVI1 gene is activated by chromosomal translocations and inversion s in approximately 5% of human acute myeloid leukemia (AML) and by ret roviral insertion in approximately 20% of murine myeloid leukemias, EV I1 encodes a nuclear DNA-binding protein having 10 zinc finger motifs in two noncontiguous domains consisting of an amino-terminal domain of seven fingers and a carboxyl domain containing three fingers, To eval uate the sequence specificity of Evi-1 binding and potentially identif y genomic targets, whole-genome PCR was utilized to isolate multiple S au3A fragments which specifically bind to the amino-terminal zinc fing er domain, The majority of these clones represented single copy sequen ces and virtually all contained variable numbers of repeats of the GAT A motif, the target sequence for the erythroid-specific transcription factor GATA-1, GST/Evi-1 fusion proteins containing the amino-terminal domain of zinc fingers bound the GATA motif in these clones as well a s to those present in the human gamma-globin promoter, similar to the binding of purified GATA-1 protein, By obtaining corresponding large g enomic clones for eight of these fragments, transcription units were f ound associated with two. One corresponded to the glyceraldehyde-3-pho sphate dehydrogenase gene and its expression was not affected by Evi-1 , The second is a novel gene whose expression is repressed in murine m yeloid cell lines that express Evi-1.