title: An HMG-like protein that can switch a transcriptional activator to a repressor.
abstract: One protein can activate some genes and repress others in the same cell. The Drosophila protein Dorsal (which, like the human protein NF-kappa B3, is a member of the Rel family of transcriptional activators) activates the twist gene and represses the zen gene in the ventral region of early embryos. Here we describe a Drosophila HMG1 protein, called DSP1 (dorsal switch protein), that converts Dorsal and NF-kappa B from transcriptional activators to repressors. This effect requires a sequence termed a negative regulatory element (NRE), found adjacent to Dorsal-binding sites in the zen promoter and adjacent to the NF-kappa B-binding site in the human interferon-beta (IFN-beta) enhancer. Previous studies have shown that another type of HMG protein, HMG I(Y), can stimulate NF-kappa B activity. Thus, the HMG-like proteins DSP1 and HMG I(Y) can determine whether a specific regulator functions as an activator or a repressor of transcription.
authors.affiliation: Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
authors.forename: N
authors.initials: N
authors.lastname: Lehming
authors.forename: D
authors.initials: D
authors.lastname: Thanos
authors.forename: J M
authors.initials: JM
authors.lastname: Brickman
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: T
authors.initials: T
authors.lastname: Maniatis
authors.forename: M
authors.initials: M
authors.lastname: Ptashne
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins; D004742:Enhancer Elements, Genetic; D025741:HMGA1a Protein; D006367:HeLa Cells; D006609:High Mobility Group Proteins / Q000378:metabolism*; D006801:Humans; D016899:Interferon-beta / Q000235:genetics; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D006609:High Mobility Group Proteins; D016328:NF-kappa B; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011994:Recombinant Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C062236:dl protein, Drosophila; D025741:HMGA1a Protein; D016899:Interferon-beta; D004247:DNA