Self-association of Gata1 enhances transcriptional activity in vivo in zebra fish embryos.
Gata1 is a prototype transcription factor that regulates hematopoiesis, yet the molecular mechanisms by which Gata1 transactivates its target genes in vivo remain unclear. We previously showed, in transgenic zebra fish, that Gata1 autoregulates its own expression. In this study, we characterized the molecular mechanisms for this autoregulation by using mutations in the Gata1 protein which impair autoregulation. Of the tested mutations, replacement of six lysine residues with alanine (Gata1KA6), which inhibited self-association activity of Gata1, reduced the Gata1-dependent induction of reporter gene expression driven by the zebra fish gata1 hematopoietic regulatory domain (gata1 HRD). Furthermore, overexpression of wild-type Gata1 but not Gata1KA6 rescued the expression of Gata1 downstream genes in vlad tepes, a germ line gata1 mutant fish. Interestingly, both GATA sites in the double GATA motif in gata1 HRD were critical for the promoter activity and for binding of the self-associated Gata1 complex, whereas only the 3'-GATA site was required for Gata1 monomer binding. These results thus provide the first in vivo evidence that the ability of Gata1 to self-associate critically contributes to the autoregulation of the gata1 gene.
Nishikawa
Keizo
K
Center for Tsukuba Advanced Research Alliance, and Institute of Basic Medical Sciences, University of Tsukuba, Tsukuba 305-8577, Japan.
Kobayashi
Makoto
M
Masumi
Atsuko
A
Lyons
Susan E
SE
Weinstein
Brant M
BM
Liu
P Paul
PP
Yamamoto
Masayuki
M
D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D008239:Lysine / Q000737:chemistry; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015533:Transcriptional Activation; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016335:Zinc Fingers / Q000235:genetics
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D011994:Recombinant Proteins; D014157:Transcription Factors; D029961:Zebrafish Proteins; C494691:gata1a protein, zebrafish; D008239:Lysine