Transcriptional cofactors of the FOG family interact with GATA proteins by means of multiple zinc fingers.
Friend of GATA-1 (FOG-1) is a zinc finger protein that has been shown to interact physically with the erythroid DNA-binding protein GATA-1 and modulate its transcriptional activity. Recently, two new members of the FOG family have been identified: a mammalian protein, FOG-2, that also associates with GATA-1 and other mammalian GATA factors; and U-shaped, a Drosophila protein that interacts with the Drosophila GATA protein Pannier. FOG proteins contain multiple zinc fingers and it has been shown previously that the sixth finger of FOG-1 interacts specifically with the N-finger but not the C-finger of GATA-1. Here we show that fingers 1, 5 and 9 of FOG-1 also interact with the N-finger of GATA-1 and that FOG-2 and U-shaped also contain multiple GATA-interacting fingers. We define the key contact residues and show that these residues are highly conserved in GATA-interacting fingers. We examine the effect of selectively mutating the four interacting fingers of FOG-1 and show that each contributes to FOG-1's ability to modulate GATA-1 activity. Finally, we show that FOG-1 can repress GATA-1-mediated activation and present evidence that this ability involves the recently described CtBP co-repressor proteins that recognize all known FOG proteins.
D000429:Alcohol Oxidoreductases; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D056970:Co-Repressor Proteins; D017124:Conserved Sequence; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D050981:Erythroid-Specific DNA-Binding Factors; D050982:GATA1 Transcription Factor; D017930:Genes, Reporter; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics; D016415:Sequence Alignment; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015003:Yeasts; D016335:Zinc Fingers / Q000235:genetics*