N. Lehming et al., CHROMATIN COMPONENTS AS PART OF A PUTATIVE TRANSCRIPTIONAL REPRESSINGCOMPLEX, Proceedings of the National Academy of Sciences of the United Statesof America, 95(13), 1998, pp. 7322-7326
The Drosophila HMG1-like protein DSP1 Has identified by its ability to
inhibit the transcriptional activating function of Dorsal in a promot
er-specific fashion in yeast, We show here that DSP1 as Hell as its ma
mmalian homolog hHMG2 bind to the mammalian protein SP100B and that SP
100B in turn binds to human homologs of HP1, The latter is a Drosophil
a protein that is inolved in transcriptional silencing. Each of these
proteins represses transcription when tethered to DNA in mammalian cel
ls. These results suggest how heterochromatin proteins might be recrui
ted to specific sites on DNA with resultant specific effects on gene e
xpression.