Synergistic activation of transcription is mediated by the N-terminal domain of Drosophila fushi tarazu homeoprotein and can occur without DNA binding by the protein.
Synergistic activation of transcription by Drosophila segmentation genes in tissue culture cells provides a model with which to study combinatorial regulation. We examined the synergistic activation of an engrailed-derived promoter by the pair-rule proteins paired (PRD) and fushi tarazu (FTZ). Synergistic activation by PRD requires regions of the homeodomain or adjacent sequences, and that by FTZ requires the first 171 residues. Surprisingly, deletion of the FTZ homeodomain does not reduce the capacity of the protein for synergistic activation, although this mutation abolishes any detectable DNA-binding activity. This finding suggests that FTZ can function through protein-protein interactions with PRD or other components of the homeoprotein transcription complex, adding a new layer of mechanisms that could underlie the functional specificities and combinatorial regulation of homeoproteins.
Ananthan
J
J
Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Florida 33101-6129.
Baler
R
R
Morrissey
D
D
Zuo
J
J
Lan
Y
Y
Weir
M
M
Voellmy
R
R
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D051717:Fushi Tarazu Transcription Factors; D005801:Genes, Homeobox / Q000235:genetics; D018398:Homeodomain Proteins; D007301:Insect Hormones / Q000235:genetics*; D008957:Models, Genetic; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins; D017384:Sequence Deletion; D014157:Transcription Factors / Q000235:genetics; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051717:Fushi Tarazu Transcription Factors; D018398:Homeodomain Proteins; D007301:Insect Hormones; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C497169:ftz protein, Drosophila