[Cloning cDNA of extracellular domain of human erythropoietin receptor and its expression in Escherichia coli].

Human erythropoietin receptor (hEpoR) plays an important role in regulating the red blood cell production by promoting the proliferation and differentiation of RBC from erythroid precursors. hEpoR is a transmembrane protein, and its extrocellular domain (sEpoR) is of great importance in Epo signal transduction pathway. We cloned the gene of sEpoR by RT-PCR from the total RNA of human fetal liver and expressed it in E. coli after insertion of the gene in the expression vector pBV220. The cloned gene was confirmed by sequencing analysis and gene product was confirmed by both Western blot and its first 11 amino acid residues sequence of the N-terminal. In vitro bioassay showed that the purified gene product can repress the growth of TF-cells in the presence of Epo.