A novel erythroid differentiation related gene EDRF2 inhibited α-globin gene expression in K562 cells

In previous studies, we found that EDRF2 was an erythroid differentiation related factor, whose expression was markedly upregulated during erythroid differentiation. It suggested that this factor played a role in erythropoiesis. By using rapid amplification of cDNA ends technology, we cloned EDRF2 gene 5 ′- and 3 ′-cDNA ends successfully. Transfection and Northern blot analysis demonstrated that EDRF2 inhibited mRNA expression of a-globin gene, while did not regulate γ-globin gene expression. Gel shift assay confirmed that DNA-binding activity of erythroid specific transcription factors GATA-1, NF-E2 and AP1 was not affected by either forced overexpression or artificial downregulation of EDRF2 gene in K562 cells. However, we detected that the negative regulator of expression of GATA-1 transcription factor was increased in EDRF2 overexpressed K562 cells. These results strongly suggested that EDRF2 was involved in a-globin gene expression and erythroid differentiation and served as a negative regulator of PU.1 transcription factor.