Inhibition of the DNA-binding activity of Drosophila suppressor of hairless and of its human homolog, KBF2/RBP-J kappa, by direct protein-protein interaction with Drosophila hairless.
We have purified the sequence-specific DNA-binding protein KBF2 and cloned the corresponding cDNA, which is derived from the previously described RBP-J kappa gene, the human homolog of the Drosophila Suppressor of Hairless [Su(H)] gene. Deletion studies of the RBP-J kappa and Su(H) proteins allowed us to define a DNA-binding domain conserved during evolution. Because Su(H) mutant alleles exhibit dose-sensitive interactions with Hairless (H) loss-of-function mutations, we have investigated whether the RBP-J kappa or Su(H) proteins directly interact with the H protein in vitro. We show here that H can inhibit the DNA binding of both Su(H) and RBP-J kappa through direct protein-protein interactions. Consistent with this in vitro inhibitory effect, transcriptional activation driven by Su(H) in transfected Drosophila S2 cells is inhibited by H. These results support a model in which H acts, at least in part, as a negative regulator of Su(H) activity. This model offers a molecular view to the antagonistic activities encoded by the H and Su(H) genes for the control of sensory organ cell fates in Drosophila. We further propose that a similar mechanism might occur in mammals.
Unité de Biologie Moléculaire de l'Expression Génique, URA 1149 Centre National de la Recherche Scientifique (CNRS), Institut Pasteur, Paris, France.
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C
Brou
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Logeat
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M
Lecourtois
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J
Vandekerckhove
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P
Kourilsky
F
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Schweisguth
A
A
Israël
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004247:DNA / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins; D017344:Genes, Insect; D006801:Humans; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D008954:Models, Biological; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D014157:Transcription Factors
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D009687:Nuclear Proteins; D011506:Proteins; C497570:RBPJ protein, human; D012097:Repressor Proteins; C088731:Su(H) protein, Drosophila; D014157:Transcription Factors; C076560:H protein, Drosophila; D004247:DNA