Phosphorylation of the erythroid transcription factor GATA-1.
GATA-1 is a zinc finger DNA-binding protein thought to be involved in the expression of the vast majority of erythroid specific genes. We have examined the phosphorylation of GATA-1 in murine erythroleukemia (MEL) cells and have mapped the sites of phosphorylation by overexpression of GATA-1 in monkey kidney COS cells. We show that GATA-1 is phosphorylated on 6 serines within its amino terminus in uninduced MEL cells and that a 7th site, serine 310, becomes phosphorylated after MEL cells are induced to differentiate by exposure to dimethyl sulfoxide. This site lies near the carboxyl boundary of the DNA-binding domain in a conserved region of the protein believed to be involved in DNA bending. Detailed analyses indicate, however, that phosphorylation at this site, or the other sites identified, does not significantly influence DNA-binding affinity or specificity, DNA bending, or transcriptional transactivation by GATA-1.
Crossley
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Division of Hematology-Oncology, Children's Hospital, Dana-Farber Cancer Institute, Boston, Massachusetts 02115.
Orkin
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D016475:3T3 Cells; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001345:Autoradiography; D001483:Base Sequence; D001665:Binding Sites; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D002522:Chlorocebus aethiops; D017124:Conserved Sequence; D017931:DNA Primers; D015342:DNA Probes; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D015870:Gene Expression; D007668:Kidney; D004915:Leukemia, Erythroblastic, Acute; D051379:Mice; D008969:Molecular Sequence Data; D010449:Peptide Mapping; D010748:Phosphopeptides / Q000737:chemistry / Q000302:isolation & purification; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation; D010957:Plasmids; D016133:Polymerase Chain Reaction; D014157:Transcription Factors / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured; D016335:Zinc Fingers
D000596:Amino Acids; D017931:DNA Primers; D015342:DNA Probes; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494689:Gata1 protein, mouse; D010748:Phosphopeptides; D010761:Phosphorus Radioisotopes; D014157:Transcription Factors; D004121:Dimethyl Sulfoxide