Effect of AML/ETO expression on NF-E2 protein levels. (A) Suppression of NF-E2 expression by the leukemic fusion protein AML/ETO. UKE-1 and K562 cells were retrovirally transduced either with the empty vector (pSF91) or with a vector expressing the AML/ETO fusion protein (pSF91-AML/ETO). At 72 hours after transduction, cells were sorted for green fluorescent protein expression, to yield a population of 100% transduced cells. Three days after the sort, protein extracts were prepared and analyzed by Western blotting for AML/ETO, NF-E2, and β-actin expression. A representative experiment is shown. (B) AML/ETO and NF-E2 expression in various hematopoietic cell lines. Total cell extracts from the indicated cell lines were subjected to Western blotting and interrogated with antibodies directed against AML/ETO, NF-E2, and beta-actin as indicated. A representative experiment is shown.