[Functional analysis of human A gamma-globin gene promoter with-173 T-->C mutation].
OBJECTIVE
To investigate the effect of the human A gamma-globin gene-173 T-->C mutation on the binding of transacting factors to the promoter and the activity of the promoter.


METHODS
Electrophoretic mobility shift assay and transient transfection assay were used in this study.


RESULTS
The A gamma-globin gene-173 T-->C mutation decreased the affinity of GATA-1 to the mutant promoter fragment (-201(-)-158) 96% (P < 0.01) and the binding of Oct-1 to the same DNA fragment 55% (P < 0.05). The activity of the mutant promoter was 2-fold (P < 0.05) as strong as that of the normal one in MELGM979 cells. The mutant and the normal promoters exhibited basically same activities in K562 and Hela cells.


CONCLUSIONS
The -173 T-->C mutation decreased dramatically the binding of GATA-1, implicating that GA-TA-1 may act as a negative regulator of A gamma-globin gene in adults. The -173 T-->C mutation may enhance the activity of A gamma-globin gene promoter in the adult erythroid cell environment.
Huang
X
X
National Laboratory of Medical Molecular Biology, Institute of Basic of Medical Sciences, CAMS and PUMC, Beijing 100005.
Zhang
J
J
Yang
X
X
Wang
Y
Y
Zhao
H
H
D000328:Adult; D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D005914:Globins / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D020014:K562 Cells; D004915:Leukemia, Erythroblastic, Acute / Q000473:pathology; D051379:Mice; D017354:Point Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494688:GATA1 protein, human; C494689:Gata1 protein, mouse; D014157:Transcription Factors; D005914:Globins