title: dSAP18 and dHDAC1 contribute to the functional regulation of the Drosophila Fab-7 element.
abstract: It was described earlier that the Drosophila GAGA factor [Trithorax-like (Trl)] interacts with dSAP18, which, in mammals, was reported to be a component of the Sin3-HDAC co-repressor complex. GAGA-dSAP18 interaction was proposed to contribute to the functional regulation of the bithorax complex (BX-C). Here, we show that mutant alleles of Trl, dsap18 and drpd3/hdac1 enhance A6-to-A5 transformation indicating a contribution to the regulation of Abd-B expression at A6. In A6, expression of Abd-B is driven by the iab-6 enhancer, which is insulated from iab-7 by the Fab-7 element. Here, we report that GAGA, dSAP18 and dRPD3/HDAC1 co-localize to ectopic Fab-7 sites in polytene chromosomes and that mutant Trl, dsap18 and drpd3/hdac1 alleles affect Fab-7-dependent silencing. Consistent with these findings, chromatin immunoprecipitation analysis shows that, in Drosophila embryos, the endogenous Fab-7 element is hypoacetylated at histones H3 and H4. These results indicate a contribution of GAGA, dSAP18 and dRPD3/HDAC1 to the regulation of Fab-7 function.
authors.affiliation: Departament de Biologia Molecular i Cel.lular, Institut de Biologia Molecular de Barcelona, CSIC Parc Científic de Barcelona, Josep Samitier, 1-5 08028 Barcelona, Spain.
authors.forename: Silvia
authors.initials: S
authors.lastname: Canudas
authors.forename: Silvia
authors.initials: S
authors.lastname: Pérez
authors.forename: Laura
authors.initials: L
authors.lastname: Fanti
authors.forename: Sergio
authors.initials: S
authors.lastname: Pimpinelli
authors.forename: Navjot
authors.initials: N
authors.lastname: Singh
authors.forename: Steven D
authors.initials: SD
authors.lastname: Hanes
authors.forename: Fernando
authors.initials: F
authors.lastname: Azorín
authors.forename: M Lluïsa
authors.initials: ML
authors.lastname: Espinás
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000032:analysis / Q000235:genetics; D004330:Drosophila / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D020868:Gene Silencing; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases / Q000235:genetics / Q000502:physiology*; D006657:Histones / Q000378:metabolism; D018398:Homeodomain Proteins / Q000096:biosynthesis / Q000235:genetics; D009154:Mutation; D020218:Response Elements; D014157:Transcription Factors / Q000032:analysis / Q000235:genetics / Q000502:physiology*
chemical_list: C062393:Abd-B proteins, Drosophila; D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D006657:Histones; D018398:Homeodomain Proteins; D014157:Transcription Factors; C063460:Trl protein, Drosophila; C407043:bicoid interacting protein 1, Drosophila; C512966:HDAC1 protein, Drosophila; D056284:Histone Deacetylase 1; D006655:Histone Deacetylases