Dynamic chromatin: concerted nucleosome remodelling and acetylation

Abstract

The flexibility of chromatin that enables translation of environmental cues into changes in genome utilisation, relies on a battery of enzymes able to modulate chromatin structure in a highly targeted and regulated manner. The most dynamic structural changes are brought about by two kinds of enzymes with different functional principles. Changes in the acetylation status of histones modulate the folding of the nucleosomal fibre. The histone-DNA interactions that define the nucleosome itself can be disrupted by ATP-dependent remodelling factors. This review focuses on recent developments that illustrate various strategies for integrating these disparate activities into complex regulatory schemes. Synergies may be brought about by consecutive or parallel action during the stepwise process of chromatin opening or closing. Tight co-ordination may be achieved by direct interaction of (de-)acetylation enzymes and remodelling ATPases or even permanent residence within the same multi-enzyme complex. The fact that remodelling ATPases can be acetylated by histone acetyltransferases themselves suggests exciting possibilities for the coordinate modulation of chromatin structure and remodelling enzymes.

Kinetic proofreading of gene activation by chromatin remodeling

“…It corresponds essentially to the scenario of Fig. 1(C) in Eberharter et al (2005), with the difference that we have placed the transcription factor at the end of the gene activation process; we comment on this difference at the end of the paper. For simplicity we only consider a two-state case, a fully acetylated and a fully deacetylated nucleosome.…”

“…Each kinetic proofreading scheme is based on equilibrium and nonequilibrium reactions (Eberharter et al, 2005). For chromatin, the equilibrium step is provided by the association of an acetylated nucleosome of concentration ͓A͔ with a remodeler ͓R͔ via the reaction ͓A͔ + ͓R͔ ↔ ͓AR͔ with the on rate r + and the off-rate r − A .…”

Histone Acetylation and Flagellin Are Essential for Legionella pneumophila-Induced Cytokine Expression

“…The acetylation status of histones is controlled by a delicate balance between HATs increasing histone acetylation, thereby reducing DNA-histone binding and facilitating gene transcription and HDACs acting in the opposing way (32,33). Recruitment of the highly related HATs p300 and CBP to the IL-8 gene promoter was observed in L. pneumophila-infected epithelial cells.…”

Schizosaccharomyces pombe Histone Acetyltransferase Mst1 (KAT5) Is an Essential Protein Required for Damage Response and Chromosome Segregation

“…Work from several experimental systems shows that ScEsa1 histone acetyltransferase is a catalytic subunit of a large protein complex called NuA4 and a smaller subcomplex, Piccolo, that is part of NuA4 (Allard et al 1999;Boudreault et al 2003;Eberharter et al 2005;Selleck et al 2005). The NuA4 complex acetylates histone H4 and H2A (Smith et al 1998;Allard et al 1999;Galarneau et al 2000).…”