4xzq
From Proteopedia
Nucleosome disassembly by RSC and SWI/SNF is enhanced by H3 acetylation near the nucleosome dyad axis
Structural highlights
Function[H2B11_XENLA] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. [H32_XENLA] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. [H4_XENLA] Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling. Publication Abstract from PubMedSignaling associated with transcription activation occurs through post-translational modification of histones and is best exemplified by lysine acetylation. Lysines are acetylated in histone tails and the core domain / lateral surface of histone octamers. While acetylated lysines in histone tails are frequently recognized by other factors referred to as "readers" that promote transcription, the mechanistic role of the modifications in the lateral surface of the histone octamer remain unclear. Using x-ray crystallography, we show that acetylated lysines 115 and 122 in histone H3 are solvent-accessible, but in biochemical assays appear not to interact with the bromodomains of SWI/SNF and RSC to enhance recruitment or nucleosome mobilization as was previously shown for acetylated lysines in H3 histone tails. Instead we find that acetylation of lysines 115 and 122 increases the predisposition of nucleosomes for disassembly by SWI/SNF and RSC up to seven-fold, independent of bromodomains, and only in conjunction with contiguous nucleosomes. Thus, in combination with SWI/SNF and RSC, acetylation of lateral surface lysines in the histone octamer serve as crucial regulators of nucleosomal dynamics distinct from the histone code readers and writers. Histone acetylation near the nucleosome dyad axis enhances nucleosome disassembly by RSC and SWI/SNF.,Chatterjee N, North JA, Dechassa ML, Manohar M, Prasad R, Luger K, Ottesen JJ, Poirier MG, Bartholomew B Mol Cell Biol. 2015 Sep 28. pii: MCB.00441-15. PMID:26416878[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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