Chromatin components as part of a putative transcriptional repressing complex.
The Drosophila HMG1-like protein DSP1 was identified by its ability to inhibit the transcriptional activating function of Dorsal in a promoter-specific fashion in yeast. We show here that DSP1 as well as its mammalian homolog hHMG2 bind to the mammalian protein SP100B and that SP100B in turn binds to human homologs of HP1. The latter is a Drosophila protein that is involved in transcriptional silencing. Each of these proteins represses transcription when tethered to DNA in mammalian cells. These results suggest how heterochromatin proteins might be recruited to specific sites on DNA with resultant specific effects on gene expression.
Lehming
N
N
Department of Molecular and Cellular Biology, Harvard University, 7 Divinity Avenue, Cambridge, MA 02138, USA.
Le Saux
A
A
Schüller
J
J
Ptashne
M
M
D000818:Animals; D034961:Antigens, Nuclear; D001324:Autoantigens / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism*; D000090266:Chromobox Protein Homolog 5; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004330:Drosophila; D029721:Drosophila Proteins; D006609:High Mobility Group Proteins / Q000378:metabolism*; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000378:metabolism
D034961:Antigens, Nuclear; D001324:Autoantigens; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; C104348:DSP1 protein, Drosophila; D029721:Drosophila Proteins; D006609:High Mobility Group Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; D012097:Repressor Proteins; D014157:Transcription Factors; C062236:dl protein, Drosophila; D000090266:Chromobox Protein Homolog 5; C066642:SP100 protein, human; D004247:DNA; D001616:beta-Galactosidase