title: ISWI remodelling of physiological chromatin fibres acetylated at lysine 16 of histone H4.
abstract: ISWI is the catalytic subunit of several ATP-dependent chromatin remodelling factors that catalyse the sliding of nucleosomes along DNA and thereby endow chromatin with structural flexibility. Full activity of ISWI requires residues of a basic patch of amino acids in the N-terminal 'tail' of histone H4. Previous studies employing oligopeptides and mononucleosomes suggested that acetylation of the H4 tail at lysine 16 (H4K16) within the basic patch may inhibit the activity of ISWI. On the other hand, the acetylation of H4K16 is known to decompact chromatin fibres. Conceivably, decompaction may enhance the accessibility of nucleosomal DNA and the H4 tail for ISWI interactions. Such an effect can only be evaluated at the level of nucleosome arrays. We probed the influence of H4K16 acetylation on the ATPase and nucleosome sliding activity of Drosophila ISWI in the context of defined, in vitro reconstituted chromatin fibres with physiological nucleosome spacing and linker histone content. Contrary to widespread expectations, the acetylation did not inhibit ISWI activity, but rather stimulated ISWI remodelling under certain conditions. Therefore, the effect of H4K16 acetylation on ISWI remodelling depends on the precise nature of the substrate.
authors: Department of Molecular Biology, Adolf Butenandt Institut, Ludwig-Maximilians-Universität München, Munich, Germany ; Center for Integrated Protein Science Munich, Munich, Germany.
authors: Henrike
authors: H
authors: Klinker
authors: Department of Molecular Biology, Adolf Butenandt Institut, Ludwig-Maximilians-Universität München, Munich, Germany.
authors: Felix
authors: F
authors: Mueller-Planitz
authors: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors: Renliang
authors: R
authors: Yang
authors: Center for Integrated Protein Science Munich, Munich, Germany ; Protein Analysis Unit, Adolf Butenandt Institut, Ludwig-Maximilians-Universität München, Munich, Germany.
authors: Ignasi
authors: I
authors: Forné
authors: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors: Chuan-Fa
authors: CF
authors: Liu
authors: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors: Lars
authors: L
authors: Nordenskiöld
authors: Department of Molecular Biology, Adolf Butenandt Institut, Ludwig-Maximilians-Universität München, Munich, Germany ; Center for Integrated Protein Science Munich, Munich, Germany.
authors: Peter B
authors: PB
authors: Becker
mesh_terms: D000107:Acetylation; D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000818:Animals; D002843:Chromatin / Q000378:metabolism*; D042002:Chromatin Assembly and Disassembly; D004331:Drosophila melanogaster / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D008239:Lysine / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000378:metabolism; D009707:Nucleosomes / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D002843:Chromatin; D006657:Histones; C086468:ISWI protein; D046912:Multiprotein Complexes; D009707:Nucleosomes; D014157:Transcription Factors; D000251:Adenosine Triphosphatases; D008239:Lysine