title: The chromatin remodelling complex B-WICH changes the chromatin structure and recruits histone acetyl-transferases to active rRNA genes.
abstract: The chromatin remodelling complex B-WICH, which comprises the William syndrome transcription factor (WSTF), SNF2h, and nuclear myosin 1 (NM1), is involved in regulating rDNA transcription, and SiRNA silencing of WSTF leads to a reduced level of 45S pre-rRNA. The mechanism behind the action of B-WICH is unclear. Here, we show that the B-WICH complex affects the chromatin structure and that silencing of the WSTF protein results in a compaction of the chromatin structure over a 200 basepair region at the rRNA promoter. WSTF knock down does not show an effect on the binding of the rRNA-specific enhancer and chromatin protein UBF, which contributes to the chromatin structure at active genes. Instead, WSTF knock down results in a reduced level of acetylated H3-Ac, in particular H3K9-Ac, at the promoter and along the gene. The association of the histone acetyl-transferases PCAF, p300 and GCN5 with the promoter is reduced in WSTF knock down cells, whereas the association of the histone acetyl-transferase MOF is retained. A low level of H3-Ac was also found in growing cells, but here histone acetyl-transferases were present at the rDNA promoter. We propose that the B-WICH complex remodels the chromatin structure at actively transcribed rRNA genes, and this allows for the association of specific histone acetyl-transferases.
authors.affiliation: Department of Cell Biology, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Vintermist
authors.forename: Stefanie
authors.initials: S
authors.lastname: Böhm
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sadeghifar
authors.forename: Emilie
authors.initials: E
authors.lastname: Louvet
authors.forename: Anethe
authors.initials: A
authors.lastname: Mansén
authors.forename: Pergiorgio
authors.initials: P
authors.lastname: Percipalle
authors.forename: Ann-Kristin
authors.initials: AK
authors.lastname: Ostlund Farrants
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry*; D001665:Binding Sites; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry*; D042002:Chromatin Assembly and Disassembly; D047369:Chromatin Immunoprecipitation; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry*; D004275:DNA, Ribosomal / Q000737:chemistry; D003850:Deoxyribonuclease I / Q000378:metabolism; D006367:HeLa Cells; D051548:Histone Acetyltransferases / Q000737:chemistry*; D006657:Histones / Q000737:chemistry; D006801:Humans; D047468:Immunoprecipitation; D008954:Models, Biological; D024461:Myosin Type I / Q000737:chemistry*; D011401:Promoter Regions, Genetic; D012335:RNA, Ribosomal / Q000737:chemistry*; D014157:Transcription Factors / Q000737:chemistry*; D014158:Transcription, Genetic; D000092468:Bromodomain Containing Proteins
chemical_list: D000251:Adenosine Triphosphatases; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D004275:DNA, Ribosomal; D003850:Deoxyribonuclease I; D051548:Histone Acetyltransferases; D006657:Histones; D024461:Myosin Type I; D012335:RNA, Ribosomal; D014157:Transcription Factors; C116750:BAZ1B protein, human; D000092468:Bromodomain Containing Proteins; C409462:SMARCA5 protein, human; C460367:MYO1C protein, human