Transgenic over-expression of GATA-1 mutant lacking N-finger domain causes hemolytic syndrome in mouse erythroid cells.
Transcription factor GATA-1 is essential for erythroid cell differentiation. GATA-binding motifs have been found in the regulatory regions of various erythroid-specific genes, suggesting that GATA-1 contributes to gene regulation during the entire process of erythropoiesis. A GATA-1 germ-line mutation results in embryonic lethality due to defective primitive erythropoiesis and GATA-1-null embryonic stem cells fails to differentiate beyond the proerythroblast stage. Therefore, the precise roles of GATA-1 in the later stages of erythropoiesis could not be clarified. Under the control of a GATA-1 gene hematopoietic regulatory domain, a GATA-1 mutant lacking the N-finger domain (DeltaNF mutant) was over-expressed in mice. These mice exhibited abnormal morphology in peripheral red blood cells (RBCs), reticulocytosis, splenomegaly, and erythroid hyperplasia, indicating compensated hemolysis. These mice were extremely sensitive to phenylhydrazine (PHZ), an agent that induces hemolysis, and their RBCs were osmotically fragile. Importantly, the hemolytic response to PHZ was partially restored by the simultaneous expression of wild-type GATA-1 with the DeltaNF mutant, supporting our contention that DeltaNF protein competitively inhibits the function of endogenous GATA-1. These data provide the first in vivo evidence that the NF domain contributes to the gene regulation that is critical for differentiation and survival of mature RBCs in postnatal erythropoiesis.
Nakano
Mayu
M
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8577, Japan.
Ohneda
Kinuko
K
Yamamoto-Mukai
Harumi
H
Shimizu
Ritsuko
R
Ohneda
Osamu
O
Ohmura
Sakie
S
Suzuki
Mikiko
M
Tsukamoto
Saho
S
Yanagawa
Toru
T
Yoshida
Hiroshi
H
Takakuwa
Yuichi
Y
Yamamoto
Masayuki
M
D000818:Animals; D001853:Bone Marrow / Q000502:physiology; D048430:Cell Shape; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism*; D004912:Erythrocytes / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D041905:Erythroid Cells; D050981:Erythroid-Specific DNA-Binding Factors; D004920:Erythropoiesis / Q000502:physiology*; D050982:GATA1 Transcription Factor; D018507:Gene Expression Regulation, Developmental; D006461:Hemolysis; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D009996:Osmotic Fragility; D018384:Oxidative Stress; D010659:Phenylhydrazines / Q000378:metabolism; D017434:Protein Structure, Tertiary; D013154:Spleen / Q000033:anatomy & histology / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; C494689:Gata1 protein, mouse; D010659:Phenylhydrazines; D014157:Transcription Factors