Cell-cycle-dependent regulation of erythropoietin receptor gene.
To understand the regulatory mechanism of erythropoietin (EPO) receptor (EPOR) gene expression, the effect of EPO on the steady-state level of EPOR mRNA was examined using the human EPO-dependent cell line UT-7 as a model system. We found that the treatment of UT-7 cells with EPO resulted in a transient decrease of the EPOR mRNA level. This transient downregulation was also induced by stimulation with granulocyte-macrophage colony-stimulating factor (GM-CSF), another stimulator of UT-7 cell growth. These results raised the possibility that EPOR gene expression is in part related to cell growth. Moreover, it was found that EPO-induced downregulation of EPOR mRNA level was preceded by a transient downregulation of GATA-1 mRNA. To examine the relationship between the expression of EPOR, GATA-1, and GATA-2 mRNA levels and the cell cycle, logarithmically growing UT-7 cells were centrifugically fractionated according to the cell-cycle phase. Both EPOR and GATA-1 mRNA levels, but not the GATA-2 mRNA level, concomitantly decreased at the G0/G1 phase and increased at the S and G2/M phases. An electrophoretic mobility shift assay (EMSA) showed that in EPO-stimulated UT-7 cells, the dynamic changes in EPOR gene expression paralleled the GATA-1 DNA-binding activity to the oligonucleotide probe containing a GATA-binding site located at the promoter region of the EPOR gene. These findings suggest that the regulation of EPOR mRNA level is mainly associated with GATA-1 gene expression in UT-7 cells undergoing proliferation, and that these serial events are under the control of, or related to, the cell cycle.
Komatsu
N
N
Department of Medicine, Institute of Hematology, Jichi Medical School, Tochigi-ken, Japan.
Kirito
K
K
Kashii
Y
Y
Furukawa
Y
Y
Kikuchi
J
J
Suwabe
N
N
Yamamoto
M
M
Miura
Y
Y
D002453:Cell Cycle; D002455:Cell Division; D002460:Cell Line; D002469:Cell Separation; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics; D050981:Erythroid-Specific DNA-Binding Factors; D004921:Erythropoietin / Q000494:pharmacology; D050982:GATA1 Transcription Factor; D050989:GATA2 Transcription Factor; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006801:Humans; D007947:Leukemia, Megakaryoblastic, Acute / Q000473:pathology; D008957:Models, Genetic; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D017467:Receptors, Erythropoietin / Q000096:biosynthesis / Q000235:genetics*; D011994:Recombinant Proteins / Q000494:pharmacology; D016192:Resting Phase, Cell Cycle; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D017467:Receptors, Erythropoietin; D011994:Recombinant Proteins; D014157:Transcription Factors; D004921:Erythropoietin; D016178:Granulocyte-Macrophage Colony-Stimulating Factor