Distinct roles for the two cGATA-1 finger domains.
We have generated and analyzed by functional assays mutations of the chicken erythroid transcription factor GATA-1. The cGATA-1 protein contains two related finger domains highly conserved across species and characteristic of the family of GATA-binding factors. We find that mutations in the C-terminal finger or adjacent basic region abolish sequence-specific DNA binding, confirming that this region constitutes a novel DNA-binding domain sufficient to recognize the consensus WGATAR motif. At least three separate regions outside of this finger II domain contribute in a cooperative manner to the trans-activation potential of the protein. As expected from previous results analyzing the mouse homolog, we find that the N-terminal finger plays a role in DNA binding by affecting the stability of the DNA-protein complex. In addition, we find mutations of finger I subtly altered in DNA-binding function which greatly diminish trans-activation. Our results support the notion that the GATA-1 protein must be positioned precisely on the GATA cis element to enable the activation of target genes.
Yang
H Y
HY
Department of Biological Sciences, University of Pittsburgh, Pennsylvania 15260.
Evans
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D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002642:Chick Embryo; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D050981:Erythroid-Specific DNA-Binding Factors; D008745:Methylation; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D015533:Transcriptional Activation; D016335:Zinc Fingers / Q000235:genetics / Q000502:physiology*
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; D014157:Transcription Factors; D004247:DNA