Department of Laboratory Medicine, University of California, San Francisco 94143-0724.
The human homolog of mouse NF-E2 was isolated from the K562 cell line and found to encode a member of the basic leucine-zipper family of DNA-binding regulatory proteins. The deduced amino acid sequence of the mouse and human proteins exhibited near identity. Comparison to the related protein, Nrf1, revealed significant homologies at isolated regions, particularly within the basic domain, suggesting that NF-E2 and Nrf1 are members of a distinct subfamily of basic leucine-zipper proteins that share similar DNA-binding properties. High levels of human NF-E2 mRNA were observed in human erythroleukemic cell lines examined. Extensive survey of human tissue samples found NF-E2 expression not limited to erythropoeitic organs. Expression in the colon and testis suggests that NF-E2 may participate in the regulation of genes other than globin.