G. Pennetta et D. Pauli, THE DROSOPHILA SIN3 GENE ENCODES A WIDELY DISTRIBUTED TRANSCRIPTION FACTOR ESSENTIAL FOR EMBRYONIC VIABILITY, Development, genes and evolution, 208(9), 1998, pp. 531-536
Expression of many mammalian genes is activated by the binding of hete
rodimers of the Myc and Max proteins to specific DNA sequences called
the E-boxes. Transcription of the same genes is repressed upon binding
to the same sequences of complexes composed of Max, Mad/Mxi1, the co-
repressors Sin3 and N-CoR, and the histone deacetylase Rpd3. Max-Mad/M
xi1 heterodimers, which bind to E-boxes in absence of co-repressors, d
o not inhibit gene expression simply by competition with Myc-Max heter
odimers, but require Sin3 and Rpd3 for efficient repression of transcr
iption. We have cloned a Drosophila homolog of Sin3 (dSin3) and found
it to be ubiquitously expressed during embryonic development. Yeast, m
ouse and; Drosophila proteins share six blocks of strong homologies, i
ncluding four potential paired amphipathic helix domains. In addition,
the domain of binding to the histone deacetylase Rpd3 is strongly con
served. Null mutations cause recessive embryonic lethality.