Interactions between an HMG-1 protein and members of the Rel family.
We show that the Drosophila protein DSP1, an HMG-1/2-like protein, binds DNA highly cooperatively with three members of the Rel family of transcriptional regulators (NF-kappaB, the p50 subunit of NF-kappaB, and the Rel domain of Dorsal). This cooperativity is apparent with DNA molecules bearing consensus Rel-protein-binding sites and is unaffected by the presence of a negative regulatory element, a sequence previously proposed to be important for mediating repression by these Rel proteins. The cooperativity observed in these DNA-binding assays is paralleled by interactions between protein pairs in the absence of DNA. We also show that in HeLa cells, as assayed by transient transfection, expression of DSP1 increases activation by Dorsal from the twist promoter and inhibits that activation from the zen promoter, consistent with the previously proposed idea that DSP1 can affect the action of Dorsal in a promoter-specific fashion.
Brickman
J M
JM
Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA.
Adam
M
M
Ptashne
M
M
D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins; D024243:HMGB1 Protein; D006367:HeLa Cells; D006609:High Mobility Group Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics; D014157:Transcription Factors; D014158:Transcription, Genetic; D014162:Transfection
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C104348:DSP1 protein, Drosophila; C084428:Dif protein, Drosophila; D029721:Drosophila Proteins; D024243:HMGB1 Protein; D006609:High Mobility Group Proteins; D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D009687:Nuclear Proteins; D010750:Phosphoproteins; D014157:Transcription Factors; C062236:dl protein, Drosophila