title: EAST affects the activity of Su(Hw) insulators by two different mechanisms in Drosophila melanogaster.
abstract: Recent data suggest that insulators organize chromatin architecture in the nucleus. The best characterized Drosophila insulator, found in the gypsy retrotransposon, contains 12 binding sites for the Su(Hw) protein. Enhancer blocking, along with Su(Hw), requires BTB/POZ domain proteins, Mod(mdg4)-67.2 and CP190. Inactivation of Mod(mdg4)-67.2 leads to a direct repression of the yellow gene promoter by the gypsy insulator. Here, we have shown that such repression is regulated by the level of the EAST protein, which is an essential component of the interchromatin compartment. Deletion of the EAST C-terminal domain suppresses Su(Hw)-mediated repression. Partial inactivation of EAST by mutations in the east gene suppresses the enhancer-blocking activity of the gypsy insulator. The binding of insulator proteins to chromatin is highly sensitive to the level of EAST expression. These results suggest that EAST, one of the main components of the interchromatin compartment, can regulate the activity of chromatin insulators.
authors.affiliation: Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334, Moscow, Russia.
authors.forename: Larisa
authors.initials: L
authors.lastname: Melnikova
authors.affiliation: Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334, Moscow, Russia.
authors.forename: Igor
authors.initials: I
authors.lastname: Shapovalov
authors.affiliation: Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334, Moscow, Russia.
authors.forename: Margarita
authors.initials: M
authors.lastname: Kostyuchenko
authors.affiliation: Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334, Moscow, Russia. georgiev_p@mail.ru.
authors.forename: Pavel
authors.initials: P
authors.lastname: Georgiev
authors.affiliation: Department of Drosophila Molecular Genetics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St., 119334, Moscow, Russia. agolovnin@mail.ru.
authors.forename: Anton
authors.initials: A
authors.lastname: Golovnin
mesh_terms: D000483:Alleles; D000818:Animals; D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation; D038101:Insulator Elements; D008297:Male; D009154:Mutation; D010641:Phenotype; D010750:Phosphoproteins / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016601:RNA-Binding Proteins / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C114107:EAST protein, Drosophila; D010750:Phosphoproteins; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C117962:mod protein, Drosophila; C083738:su(Hw) protein, Drosophila
keywords: CP190; Chromatin insulators; Mod(mdg4); Nuclear bodies; Repression of transcription