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SU(VAR)3‐7, a Drosophila heterochromatin‐associated protein and companion of HP1 in the genomic silencing of position‐effect variegation
Author(s) -
Cléard Fabienne,
Delattre Marion,
Spierer Pierre
Publication year - 1997
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/16.17.5280
Subject(s) - biology , heterochromatin , variegation (histology) , heterochromatin protein 1 , position effect , gene silencing , genetics , drosophila melanogaster , chromosome , gene
An increase in the dose of the Su(var)3‐7 locus of Drosophila melanogaster enhances the genomic silencing of position‐effect variegation caused by centromeric heterochromatin. Here we show that the product of Su(var)3‐7 is a nuclear protein which associates with pericentromeric heterochromatin at interphase, whether on diploid chromosomes from embryonic nuclei or on polytene chromosomes from larval salivary glands. The protein also associates with the partially heterochromatic chromosome 4. As these phenotypes and localizations resemble those described by others for the Su(var)2‐5 locus and its heterochromatin‐associated protein HP1, the presumed co‐operation of the two proteins was tested further. The effect of the dose of Su(var)3‐7 on silencing of a number of variegating rearrangements and insertions is strikingly similar to the effect of the dose of Su(var)2‐5 reported by others. In addition, the two loci interact genetically, and the two proteins co‐immunoprecipitate from nuclear extracts. The results suggest that SU(VAR)3‐7 and HP1 co‐operate in building the genomic silencing associated with heterochromatin.