title: Differential targeting of two distinct SWI/SNF-related Drosophila chromatin-remodeling complexes.
abstract: The SWI/SNF family of ATP-dependent chromatin-remodeling factors plays a central role in eukaryotic transcriptional regulation. In yeast and human cells, two subclasses have been recognized: one comprises yeast SWI/SNF and human BAF, and the other includes yeast RSC and human PBAF. Therefore, it was puzzling that Drosophila appeared to contain only a single SWI/SNF-type remodeler, the Brahma (BRM) complex. Here, we report the identification of two novel BRM complex-associated proteins: Drosophila Polybromo and BAP170, a conserved protein not described previously. Biochemical analysis established that Drosophila contains two distinct BRM complexes: (i) the BAP complex, defined by the presence of OSA and the absence of Polybromo and BAP170, and (ii) the PBAP complex, containing Polybromo and BAP170 but lacking OSA. Determination of the genome-wide distributions of OSA and Polybromo on larval salivary gland polytene chromosomes revealed that BAP and PBAP display overlapping but distinct distribution patterns. Both complexes associate predominantly with regions of open, hyperacetylated chromatin but are largely excluded from Polycomb-bound repressive chromatin. We conclude that, like yeast and human cells, Drosophila cells express two distinct subclasses of the SWI/SNF family. Our results support a close reciprocity of chromatin regulation by ATP-dependent remodelers and histone-modifying enzymes.
authors.affiliation: Gene Regulation Laboratory, Centre for Biomedical Genetics, Department of Molecular and Cell Biology, Leiden University Medical Centre, 2300 RA Leiden, The Netherlands.
authors.forename: Lisette
authors.initials: L
authors.lastname: Mohrmann
authors.forename: Karin
authors.initials: K
authors.lastname: Langenberg
authors.forename: Jeroen
authors.initials: J
authors.lastname: Krijgsveld
authors.forename: Arnoud J
authors.initials: AJ
authors.lastname: Kal
authors.forename: Albert J R
authors.initials: AJ
authors.lastname: Heck
authors.forename: C Peter
authors.initials: CP
authors.lastname: Verrijzer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: C485119:BAP170 protein, Drosophila; D018797:Cell Cycle Proteins; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D046911:Macromolecular Substances; D009687:Nuclear Proteins; C102195:PBRM1 protein, human; D021122:Protein Subunits; D015534:Trans-Activators; D014157:Transcription Factors; C086469:brm protein, Drosophila; C117995:osa protein, Drosophila