STAT1 is involved in signal transduction in the EPO induced HEL cells.
Erythropoietin (EPO) is the major regulator of mammalian erythropoisis, which stimulates the growth and differentiation of hematopoietic cells through interaction with its receptor (EPO-R). Here we use HEL cells (a human erythro-leukemia cell line) as a model to elucidate the pathway of signal transduction in the EPO-induced HEL cells. Our data show that the EPOR (EPO receptor) on the surface of HEL cells interacts with the Janus tyrosine protein kinase (Jak2) to transduce intracellular signals through phosphorylation of cytoplasmic proteins in EPO-treated HEL cells. Both STAT1 and STAT5 in this cell line are tyrosine-phosphorylated and translocated to nucleus following the binding of EPO to HEL cells. Furthermore, the binding of both STAT1 and STAT5 proteins to specific DNA elements (SIE and PIE elements) is revealed in an EPO-dependent manner. Our data demonstrate that the pathway of signal transduction following the binding of EPO to HEL cells is similar to immature erythroid cell from the spleen of mice infected with anemia strain of Friend virus.
Shanghai Institute of Cell Biology, Chinese Academy of Sciences, China.
J
J
Chu
C Y
CY
Gui
J
J
Fan
X D
XD
Tang
R L
RL
Qiao
D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D016384:Consensus Sequence; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D004921:Erythropoietin / Q000378:metabolism / Q000494:pharmacology*; D006801:Humans; D053613:Janus Kinase 1; D053614:Janus Kinase 2; D004915:Leukemia, Erythroblastic, Acute; D008894:Milk Proteins; D009687:Nuclear Proteins / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D017467:Receptors, Erythropoietin / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D050794:STAT1 Transcription Factor; D050799:STAT5 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D008894:Milk Proteins; D009687:Nuclear Proteins; D011518:Proto-Oncogene Proteins; D017467:Receptors, Erythropoietin; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D050799:STAT5 Transcription Factor; D015534:Trans-Activators; D004921:Erythropoietin; D011505:Protein-Tyrosine Kinases; C507904:JAK1 protein, human; C507924:JAK2 protein, human; D053613:Janus Kinase 1; D053614:Janus Kinase 2