Human ITCH Is a Coregulator of the Hematopoietic Transcription Factor NF-E2

Abstract We have cloned a new protein that interacts with the hematopoietic DNA-binding transcription factor, p45/NF-E2, by screening a human erythroleukemia cell cDNA library with the yeast two-hybrid approach. Predicted peptide sequence and chromosomal mapping identified the cloned molecule to be the product of the human ortholog of the mouse Itch gene, which has been implicated previously in the regulation of growth and differentiation of erythroid and lymphoid cells. Transfection experiments indicate that this human ITCH protein can act as a transcriptional corepressor of p45/NF-E2. Our data provide novel insights into the functional roles of the mammalian ITCH proteins in the development of hematopoietic cell lineages.