title: Erythropoietin stimulates phosphorylation and activation of GATA-1 via the PI3-kinase/AKT signaling pathway.
abstract: Erythropoietin (Epo) stimulation of its receptor's downstream signaling pathways and optimum function of GATA-1 transcription factor are both essential for normal erythroid cell development. Epo-receptor (EpoR) signaling and GATA-1 regulate proliferation, survival, differentiation, and maturation of erythroid cells. Whether any signal that is generated by EpoR targets GATA-1 or affects GATA-1 transcriptional activity is not known. Here, we demonstrate that stimulation of EpoR results in phosphorylation of GATA-1 at serine 310 (S310) in primary fetal liver erythroid progenitors and in cultured erythroid cells. We show that phosphorylation of GATA-1 is important for Epo-induced maturation of fetal liver erythroid progenitor cells. The PI3-kinase/AKT signaling pathway is identified as a mediator of Epo-induced phosphorylation of GATA-1. AKT serine threonine kinase phosphorylates GATA-1S310 in vitro and in erythroid cells and enhances GATA-1 transcriptional activity. These data demonstrate that EpoR signaling phosphorylates GATA-1 and modulates its activity via the PI3-kinase/AKT signaling pathway.
authors.affiliation: Department of Gene and Cell Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Claire
authors.initials: C
authors.lastname: Kitidis
authors.forename: Mark D
authors.initials: MD
authors.lastname: Fleming
authors.forename: Harvey F
authors.initials: HF
authors.lastname: Lodish
authors.forename: Saghi
authors.initials: S
authors.lastname: Ghaffari
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D015672:Erythroid Precursor Cells / Q000166:cytology / Q000502:physiology*; D004920:Erythropoiesis / Q000187:drug effects* / Q000502:physiology; D004921:Erythropoietin / Q000378:metabolism / Q000494:pharmacology*; D005333:Fetus / Q000166:cytology / Q000378:metabolism*; D050982:GATA1 Transcription Factor / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000502:physiology; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D017467:Receptors, Erythropoietin / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects* / Q000502:physiology
chemical_list: D050982:GATA1 Transcription Factor; D017467:Receptors, Erythropoietin; D004921:Erythropoietin; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt