Premium
Local action of long‐range repressors in the Drosophila embryo
Author(s) -
Nibu Yutaka,
Zhang Hailan,
Levine Michael
Publication year - 2001
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/20.9.2246
Subject(s) - biology , embryo , drosophila (subgenus) , genetics , repressor , drosophila melanogaster , action (physics) , range (aeronautics) , drosophilidae , microbiology and biotechnology , evolutionary biology , gene , transcription factor , physics , materials science , quantum mechanics , composite material
Previous studies have identified two corepressors in the early Drosophila embryo: Groucho and dCtBP. Both proteins are recruited to the DNA template by interacting with short peptide motifs conserved in a variety of sequence‐specific transcriptional repressors. Once bound to DNA, Groucho appears to mediate long‐range repression, while dCtBP directs short‐range repression. The short‐range Krüppel repressor was converted into a long‐range repressor by replacing the dCtBP interaction motif (PxDLSxH) with a Groucho motif (WRPW). The resulting chimeric repressor causes a different mutant phenotype from that of the native Krüppel protein when misexpressed in transgenic embryos. The different patterning activities can be explained on the basis of long‐range silencing within the hairy 5′ regulatory region. The analysis of a variety of synthetic transgenes provides evidence that Groucho‐dependent long‐range repressors do not always cause the dominant silencing of linked enhancers within a complex cis ‐regulatory region. We suggest a ‘hot chromatin’ model, whereby repressors require activators to bind DNA.