[Analysis of the binding of GATA factors to the regulatory elements of human beta-globin gene in hydroxyurea-induced and uninduced HEL cells].
HEL cells, a human erythroleukemia cell line, expressing mainly the gamma-globin genes, small amount of epsilon-globin gene, but not beta-globin gene. Our previous studies demonstrated that beta-globin gene could be expressed in HEL cells induced by hydroxyurea. However, the molecular mechenism is still unknown. Here the binding patterns of GATA factors (GATA-1 and GATA-2) to the regulatory elements of human beta-globin gene were examined with the nuclear extracts from hydroxyurea-induced and uninduced HEL cells. Our results showed in EMSA assay that GATA factors could bind to the core sequence of HS2(-10681 to -10971 bp), the 3' flanking sequence of HS2 core(-10323 to -10680 bp) and the promoter of human beta-globin gene(+20 to -112 bp). However, the binding patterns between hydroxyurea-induced and uninduced HEL cells were different. Furthermore, by using Western-blot analysis, our data showed that the amount of GATA-2 was decreased in hydroxyurea-induced HEL cells. In contrast to GATA-2, the amount of GATA-1 was increased in hydroxyurea-induced HEL cells. These results showed that the different members of GATA family might play different roles during the differentiation of erythrocytes. GATA-1 may stimulate the differentiation of HEL cells, while GATA-2 can probably inhibit the differentiation of HEL cells.
Zhao
H
H
Shanghai Institute of Cell Biology, Chinese Academy of Science, Shanghai 200031, China.
Zhang
S B
SB
Jiang
S
S
Qian
R L
RL
D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000502:physiology*; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D050989:GATA2 Transcription Factor; D015870:Gene Expression; D005914:Globins / Q000096:biosynthesis / Q000235:genetics*; D006801:Humans; D006918:Hydroxyurea; D004915:Leukemia, Erythroblastic, Acute / Q000378:metabolism* / Q000473:pathology; D014157:Transcription Factors / Q000502:physiology*; D014407:Tumor Cells, Cultured
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; D014157:Transcription Factors; D005914:Globins; D006918:Hydroxyurea