Erythropoietin production switches from fetal liver to adult kidney during development. GATA transcription factors 2 and 3 could be involved in modulating this switch, because they were shown to negatively regulate erythropoietin gene transcription through a promoter proximal GATA site. Herein, we analyzed the role of several GATA factors in the regulation of the erythropoietin gene in human liver and in hepatoma cells. Although GATA-3 expression in hepatocytes increases during human development, erythropoietin mRNA accumulation is unaltered in mutant mice lacking GATA-3. We found that GATA-2, -3, -4, and -6 are all expressed in human hepatocytes and that GATA-4 exhibits the most prominent Epo promoter binding activity in vitro and in vivo. Inhibition of GATA-4 expression by RNA interference leads to a dramatic reduction in Epo gene transcription in Hep3B cells. Moreover, GATA-4 expression is high and limited to hepatocytes in the fetal liver, whereas GATA-4 expression in the adult liver is low and restricted to epithelial cells surrounding the biliary ducts. Thus, GATA-4 is critical for transcription of the Epo gene in hepatocytes and may contribute to the switch in the site of Epo gene expression from the fetal liver to the adult kidney VSports手机版. .